I. Overview

[1] In February 2014 Dr. Glasine Lawson, a gynecologist and obstetrician, performed a laparoscopically-assisted surgical procedure on the plaintiff Christine Knight at Stevenson Memorial Hospital in Alliston, during which she removed Ms. Knight’s uterus and right ovary. Dr. Lawson had already removed Ms. Knight’s left ovary in an earlier operation two years earlier.

[2] The February 2014 operation seemed to go well, and Ms. Knight was discharged from the hospital the next day. Unfortunately, and unbeknownst to anyone at the time, it now seems likely that during the surgery Dr. Lawson accidentally damaged Ms. Knight’s right ureter, which is one of two tubes that drains urine from her kidneys to her bladder.

[3] Ms. Knight began feeling unwell a few days after the surgery, and on the fifth day she returned to the hospital. A CT scan showed that she had what appeared to be an abscess in her lower pelvis that was contacting her right ureter, which was distended, and that her right kidney was also swollen.

[4] The next day Ms. Knight was transferred back to Dr. Lawson’s care at Stevenson Memorial. Dr. Lawson decided that the cause of the problem with Ms. Knight’s right ureter and kidney and was either that the abscess was compressing her ureter and causing a blockage, or that she had a kidney infection. She put Ms. Knight on antibiotics with a view to addressing both of these potential issues. However, Dr. Lawson did not consider the alternative possibility that Ms. Knight’s ureter might have been injured during the surgery, and did not seek advice from a urologist.

[5] After five days in hospital on antibiotics Ms. Knight was feeling better and she was discharged. Eight days later she returned to the hospital, again feeling unwell. Tests showed that she now had a large collection of fluid in her abdomen, and at some point urine began leaking uncontrollably out of her vagina. A new CT scan revealed that Ms. Knight’s right ureter was now leaking, and that urine was collecting in her abdomen and draining out of her vagina through sutures from the operation, a condition known as a ureterovaginal fistula.

[6] The new CT scan clearly showed that Ms. Knight had a ureteric injury, and because Stevenson Memorial did not have any urologists on staff, Dr. Lawson immediately arranged for Ms. Knight to be transferred to a different hospital in Newmarket and put under the care of a urologist.

[7] The urologist, Dr. Steve Kim, successfully inserted a stent into Ms. Knight’s right ureter, but the hole in her ureter did not heal on its own, and Ms. Knight ultimately required open surgery to repair her ureter and reimplant the end into her bladder. Dr. Kim could not perform this surgery until late June 2014 because he had to wait for the swelling from the original operation to subside. During this time Ms. Knight had to have drainage tubes in her abdomen and right kidney and a catheter in her bladder, all of which caused her significant discomfort and did not entirely stop urine from leaking out of her vagina.

[8] After the June 2014 repair surgery Ms. Knight began to feel better, and over the next two months the drainage tubes and catheter were removed. By the fall of 2014 she had largely recovered, although she remained off work until 2015. She has now made essentially a full recovery.

[9] Ms. Knight has sued Dr. Lawson for the tort of negligence.[^1] It is common ground that Dr. Lawson probably accidentally injured Ms. Knight’s right ureter during the surgery. Although surgical ureteric injuries are not common, they are a known risk of pelvic surgery, and they sometimes happen even when the surgeon takes reasonable precautions to avoid them. Importantly, Ms. Knight does not claim that Dr. Lawson was negligent when she injured Ms. Knight’s ureter in the first place.

[10] Instead, Ms. Knight maintains that Dr. Lawson actions after she damaged Ms. Knight’s ureter fell below the applicable standard of care in two different respects. First, Ms. Knight contends that Dr. Lawson was negligent when she failed to detect the injury before finishing the February 2014 surgery. As I will discuss, the key question in relation to this theory of liability is whether it can be inferred that Dr. Lawson failed to properly check Ms. Knight’s ureters at the end of the operation.

[11] Ms. Knight’s second, and alternative, theory of liability is that when she later returned to the hospital and the CT scan showed that she had a distended right ureter and a swollen right kidney, Dr. Lawson fell below the standard of care when she did not consider the possibility that Ms. Knight might have suffered a ureteric injury during the surgery, and for this reason failed to seek advice from a urologist.

[12] Dr. Lawson denies that she was negligent. She maintains that she did properly check Ms. Knight’s injuries during the surgery, even though she did not specifically mention doing this in her operative notes. Dr. Lawson acknowledges that when Ms. Knight returned to her care six days later she did not consider the possibility that Ms. Knight had a surgical ureteric injury, but contends that this was not a breach of the applicable standard of care of a reasonable and prudent gynecologist in the circumstances.

[13] In the alternative, Dr. Lawson argues that even if she was negligent in either or both of these ways, her errors caused Ms. Knight no harm, since the evolution of Ms. Knight’s presentation, her treatment, and the eventual outcome would have been the same even if her ureteric injury had been detected sooner.

[14] As I will now explain, I have concluded that the evidence supports Dr. Lawson’s position on most, although not all, of these disputed issues.

[15] On the first theory of negligence – Dr. Lawson’s alleged failure to identify the ureteric injury during the operation – I find that the plaintiff has not demonstrated on a balance of probabilities that Dr. Lawson failed to properly examine Ms. Knight’s ureters for potential injuries at the end of the surgery. Dr. Lawson’s failure to detect the injury to Ms. Knight’s right ureter does not imply that her examination was inadequate, because the injury was unlikely to have been visually observable at the time.

[16] Ms. Knight’s second theory of liability is that Dr. Lawson fell short of the applicable standard of care after Ms. Knight returned to the hospital, feeling unwell and with a distended right ureter and swollen right kidney, and Dr. Lawson failed to consider the possibility that she might have a surgical ureteric injury, and accordingly failed to consult with a urologist.

[17] There is conflicting expert opinion evidence about whether a reasonable and prudent gynecologist who did properly consider the possibility of a ureteric injury would necessarily have consulted with a urologist immediately. However, Dr. Lawson never turned her mind to this possibility at all. As I will explain, I find that a reasonable and prudent gynecologist in Dr. Lawson’s position ought to have considered the possibility, and that in these circumstances her failure to consult with a urologist fell below the standard of care.

[18] However, I also find that even if Dr. Lawson had referred Ms. Knight to a urologist at this point, the earlier referral would not have made any real difference to Ms. Knight’s course of treatment or its outcome.

[19] Even if I assume that a urologist would have diagnosed the ureteric injury and successfully inserted a ureteric stent at this time, which would have been approximately two weeks earlier than Ms. Knight was actually stented, I am satisfied that the probable nature of Ms. Knight’s injury made it unlikely to heal on its own even with earlier stenting. She probably still would have required surgery to repair and reimplant her damaged ureter, and this surgery could not have been performed any more quickly that it was, even if she had been diagnosed two weeks earlier. Moreover, earlier stenting is unlikely to have prevented the hole from forming in the wall of Ms. Knight’s right ureter through which urine leaked out, and she still would have developed a ureterovaginal fistula and would have had to live with multiple drainage tubes and catheters for several months while she was waiting to have the repair and reimplantation surgery.

[20] In summary, although I find that Ms. Knight has shown that Dr. Lawson failed to meet the standard of care of a reasonable and prudent gynecologist, she has not demonstrated that Dr. Lawson’s negligence caused her any harm. It follows that her action must be dismissed.

II. The evidence

[21] I will now summarize the evidence at trial. As I do so, I will set out my findings on a few disputed factual points, but will postpone my consideration of most of the main contested factual disputes in this case until later in my reasons.

[22] I heard evidence from six witnesses. Ms. Knight and Dr. Lawson both testified, as did four medical experts: two gynecologists and two urologists, one of each from each side.

[23] The plaintiff’s medical expert witnesses were Dr. Andrew Browning, a gynecologist, and Dr. Richard Casey, a urologist. The defence’s experts were Dr. Glen Hunter, a gynecologist, and Dr. Roger Buckley, a urologist.

[24] All four expert witnesses have impressive credentials, and I was satisfied that they were each well qualified to give opinion evidence in their respective fields of expertise. However, a disputed issue that arose during the trial, and which I will address later, is whether Dr. Casey, a urologist, can properly give opinion evidence about the standard of care of a reasonable and prudent gynecologist.

[25] Another dispute that arose at the start of the trial was whether various medical illustrations commissioned by the plaintiff’s counsel should be admitted. In an earlier ruling, I held that the illustrations could be used at trial as demonstrative aids, but that I would instruct myself that they are not evidence, and would remind myself that they do not always accurately represent what happened in Ms. Knight’s case. I have found the illustrations somewhat useful as a general guide to basic anatomical structure, but am mindful of their limitations and have not relied on them to any significant extent when considering the factual issues in dispute between the parties.

A. Dr. Lawson’s professional background and experience

[26] Dr. Glasine Lawson obtained her medical degree in 1992. She completed her preliminary residency in 1996 and her residency in obstetrics and gynecology in 2002, and became certified with the American Board of Obstetrics and Gynecology in 2004.

[27] Dr. Lawson did her medical training and residencies in the United States and spent her first years of medical practice there. In 2008 she returned home to Canada and began a general obstetrics and gynecology practice at Stevenson Memorial Hospital in Alliston. The hospital has approximately forty beds, and its facilities are limited compared to those available in larger hospitals, such as the Royal Victoria Hospital in Barrie (“RVH”). In February 2014 there were only three physicians on the staff of Stevenson Memorial who regularly performed surgery there, including Dr. Lawson. A few visiting doctors occasionally carried out surgery at Stevenson, but there were no visiting urologists. Patients at Stevenson who needed urological care would have to be transferred to a larger hospital, with RVH in Barrie and Southlake Regional Health Centre in Newmarket being the two closest options.

B. The February 13, 2014 surgery performed on Ms. Knight by Dr. Lawson

[28] In February 2014 Christine Knight was 41 years old. She was the single parent of a six year old son, and worked as a receptionist at a law office. She had recently returned to school and trained as a paralegal but had not passed her qualifying exam.

[29] In 2014 Ms. Knight had already been a patient of Dr. Lawson’s for several years. In July 2012, she had seen Dr. Lawson about recurring pelvic pain she had been experiencing because of a cyst on her left ovary, and Dr. Lawson ultimately performed a laparoscopic surgical procedure in which she removed Ms. Knight’s left ovary and fallopian tube.

[30] During laparoscopic surgery, a tiny camera is inserted into the patient’s body through a small incision, and the surgeon then uses the camera’s images to guide instruments that are inserted through other small incisions, while a surgical assistant points the camera so the operating surgeon can see what he or she is doing.

[31] After the 2012 operation Ms. Knight continued to have recurring pelvic pain for the next year and a half. In March 2013, imaging showed that she had an enlarged cyst on her right ovary, which Dr. Lawson laparoscopically removed in May 2013. Ms. Knight continued to have pelvic issues, and in September 2013 imaging showed that she had developed another cyst on her right ovary. After further consultation with Dr. Lawson, Ms. Knight decided to have the problem permanently addressed by having Dr. Lawson surgically remove her uterus, right ovary and fallopian tube. In medical terminology, this operation is known as a “hysterectomy with right salpingo-oophorectomy”. The specific form of surgery that Dr. Lawson planned to perform on Ms. Knight is known as a “laparoscopic assisted vaginal hysterectomy (LAVH) with right salpingo-oophorectomy”. I will describe it in greater detail below.

[32] Dr. Lawson estimated that she has performed the LAVH procedure approximately 120 times as a practicing physician, and over 200 times altogether once her experience as a medical resident is included. When she performed this surgery on Ms. Knight on February 13, 2014 she was assisted by another gynecologist, Dr. Richard Simms, whose main job was to hold and position the laparoscope so that Dr. Lawson could see what she was doing. Dr. Lawson estimated that she and Dr. Simms had performed this procedure together approximately 30 to 40 times over the past four years, prior to operating on Ms. Knight.

[33] During the February 13, 2014 surgery, Dr. Lawson and Dr. Simms inserted a tiny camera into Ms. Knight’s abdomen through a small incision near the midline. They then inserted surgical instruments through two more small incisions, which Dr. Lawson used to sever and cauterize the blood vessels that supply the uterus, right ovary and fallopian tube. She also severed and cauterized most of the ligaments that hold these organs in place, as well as some scar tissue that had formed between Ms. Knight’s uterus and bowel. Dr. Lawson then made an incision at the end of Ms. Knight’s vagina, through which she severed and cauterized the remaining blood vessels and ligaments in order to free the organs for removal. She then removed them through Ms. Knight’s vagina, before closing the end with sutures.

[34] One of the known risks of the LAVH procedure is that the surgeon may accidentally damage the patient’s ureters. These are a pair of muscular tubes through which urine drains from the left and right kidneys to the bladder. Each ureter is approximately 24 centimetres long and has roughly the diameter of a phone charging cable. The ureters can be particularly hard for a surgeon to see at the end where they enter the bladder, which in medical terminology is referred to as the distal end, because at that point they become concealed by fatty tissue.

[35] Ureteric injuries during gynecological surgery are not common, but they are a known risk and can have serious consequences. To reduce the chances of damaging the ureters during gynecological surgery, reasonable and prudent surgeons will try to locate them at the start of the operation. They will also try to check the ureters for damage at the conclusion of the procedure. However, as I will discuss, damage to a ureter will not always be visually observable, depending on the nature of the injury.

[36] Dr. Lawson testified that she was aware of the risk of ureteric injury during the LAVH procedure, although she had never previously had a case where this had happened. She detailed the steps that she routinely took to reduce this risk, explaining that at several different points during the LAVH procedure she and her assistant would distend the patient’s abdomen with carbon dioxide gas and check her ureters. They would specifically look for peristalsis, which is a visible muscular contraction that runs along tubular organs such as ureters and bowels. They would check the patient’s ureters before moving to the vaginal portion of the surgery, and then distend her abdomen with gas and check them again after closing the vaginal cuff. Dr. Lawson acknowledged that she no longer had a “definitive memory” of performing the February 13, 2014 operation on Ms. Knight, but testified that she always carried out this procedure in the same step-by-step manner. She did not specifically mention checking Ms. Knight’s ureters in her post-operative report, but explained that it was not her usual practice to include this detail.

[37] Dr. Lawson testified further that if she had known at the time of the surgery that she had damaged one of Ms. Knight’s ureters, she would have consulted a urologist. Since there was no urologist available at Stevenson Memorial Hospital, if the need for Ms. Knight to be seen by a urologist had arisen, Dr. Lawson would have had to complete the surgery and then transfer Ms. Knight by ambulance to the closest hospital where there was a urologist available, which would likely have been either RVH in Barrie or Southlake in Newmarket.

[38] Dr. Lawson explained further that if she had been unsure during the surgery whether one of Ms. Knight’s ureter might have been damaged, she would have used intravenous dye to check for a leak. If she had become concerned about a possible ureteric injury postoperatively, she would have ordered a CT scan, which was something that could be done at Stevenson Memorial, although only during weekdays. Dr. Lawson also testified that if she had had any concerns about a possible ureteric injury either during or after the operation she would have documented these concerns in her notes.

C. The possible ways a patient’s ureter can be injured during pelvic surgery

[39] As I have noted, Ms. Knight does not suggest that Dr. Lawson’s performance of the February 13, 2014 surgery itself fell below the applicable standard of care. However, it is common ground that Dr. Lawson very likely did accidentally damage Ms. Knight’s right ureter during the operation.

[40] As I will now discuss, there is no conclusive evidence about exactly how the injury occurred, but the four medical experts who testified at trial outlined several possible mechanisms, and three of them agreed that one – an ischemic injury caused by the thermal cautery device Dr. Lawson used during the operation – was the most likely.

[41] The medical experts all agreed that there are three main ways that a patient’s ureter can be accidentally damaged during pelvic surgery.

[42] First, the surgeon can accidentally cut the wall of the ureter with a surgical instrument, creating a hole or sometimes severing the ureter entirely. These types of injuries are the easiest to detect during surgery, because urine will immediately start leaking through the hole or the severed end. These injuries are also the most amenable to repair if they are identified right away, because the blood supply to the ureter wall will not have been disrupted. Dr. Buckley explained that in this situation there are “two vascular ends that you can repair, if its recognized immediately”.

[43] The second mechanism of injury is that the ureter can be crushed with a surgical clamp or caught up in a suture. This can either wholly or partially block the ureter, preventing urine from draining into the bladder and causing it to back up in the upper end of the ureter and the kidneys.

[44] The clamp or suture can also cut off the blood supply to the ureter wall, causing the tissue to die and break down, which eventually results in a hole forming in the ureteric wall, through which urine starts leak out.

[45] The third mechanism of injury is that a surgeon who is using a thermal device to cauterize veins and arteries can accidentally damage the blood vessels that supply the ureteric wall. Dr. Hunter explained:

We often do use thermal energy for cauterization during these procedures. And there’s … sometimes thermal spread from these instruments that can damage the vasculature to the ureter which subsequently then can cause nephrosis or a sort of death of the area around the ureter, then subsequent breakdown of the wall of the uterus later on.

[46] These two last categories of injury, in which a hole develops in the ureter over time because the blood supply to the ureteric wall is disrupted, causing tissue death, are referred to as “ischemic” injuries.

[47] The four medical expert witnesses all agreed that surgical ureteric injuries of any type are rare, and that most gynecologists would see no more than a few such injuries during their careers, if any.

[48] The experts had varying levels of personal experience dealing with such injuries themselves.

[49] Dr. Browning recalled having had two cases during which a patient had suffered a laceration-type injury during surgery that had been detected intraoperatively. He also explained that if a gynecologist performing surgery checked the ureters and noticed that a ureter had been accidentally caught up in a suture, he or she could fix the problem without calling in a urologist by cutting the suture and re-doing it. He described this as something that “happens all the time”.

[50] Dr. Browning suggested that a thermal injury to the ureter might be observable intraoperatively because “if you follow the ureter’s path post up you would see, like a charcoal typical type of look where … you clearly cauterized the ureter and therefore [would] be able to examine it”. However, he acknowledged that he had “never had a case where I had a thermal injury to a ureter and had to call a urologist in to look at it.”

[51] Dr. Hunter had never personally had a case in which a ureteric injury had been identified during gynecological surgery. None of his own patients had ever had a surgical ureteric injury diagnosed after the fact, but he was aware of a handful of cases involving colleagues where this had happened. In his opinion, a surgeon would be unlikely to notice a thermal devascularization injury intraoperatively, because “the ureter would look totally normal at that particular time”.

[52] Unsurprisingly, the two urologists who testified at trial both had more personal experience with ureteric injuries than either of the gynecological experts.

[53] Dr. Casey estimated that during his nearly forty years of surgical practice he would see a ureteric injury perhaps every two or three years, and had probably seen ten to fifteen in total in his career.

[54] Dr. Buckley, who has been practicing as a urologist for nearly as long as Dr. Casey, testified that he had “probably conservatively done more than a hundred”, many of which had been gynecological surgery cases. He observed that this was an unusually high number, explaining that he had developed a particular interest in ureteric reimplantation surgery during his residency, and that as a result he “took over doing all the ureteric injuries from my senior colleagues” at the hospital where he spent most of his career, which had a high volume of gynecological and obstetrical surgeries.

D. Ms. Knight’s discharge from Stevenson Memorial (February 14, 2014)

[55] After the February 13, 2014 operation Ms. Knight was hospitalized overnight. She was discharged the next day, at which time she appeared to be recovering well.

[56] Dr. Simms, who prepared the discharge summary, noted that Ms. Knight had an elevated blood creatinine level. Creatinine is a waste product generated by muscle metabolism, and elevated levels in the blood can sometimes indicate a problem with kidney function. Dr. Simms commented in his discharge summary:

I see that she has an elevated creatinine of 115 measured February 14, 2014. There was no problem with her ureters at the time of the procedure. I have arranged for a repeat creatinine level to be done as well as other blood tests to be done as an outpatient in the next one or two days and the results will go to Dr. Lawson and to Dr. Pinto [Ms. Knight’s family doctor].

The patient knows the importance of having these tests carried out. She otherwise appears well. She will be seen in the future by her family doctor and Dr. Lawson in about four weeks but we will see her earlier if her creatinine level remains elevated. The normal value range would be between 46 and 92 and her value is 115 measured on February 14.

[57] Dr. Simms also made a handwritten note on the lab report in which he circled the elevated creatinine number and indicated that he had “arranged for a repeat test to be done as an outpatient”.

[58] Although Dr. Browning and Dr. Hunter both testified that they would not have routinely ordered creatinine level testing as part of their patients’ post-surgery blood work, Dr. Lawson testified that she had been trained to routinely include this as part of her post-operative blood test requisitions. She did not order creatinine level testing for Ms. Knight because of any specific concern she had about Ms. Knight’s kidney functioning, but because it was something she always did. Dr. Lawson added that if she had been worried about the possibility of Ms. Knight having a ureteric injury she would not only have noted this in her post-operative report, but would also have ordered a CT scan. She did not do either of these things because she had no such concerns.

[59] Ms. Knight acknowledges that she did not have the follow-up blood test done, but testified that Dr. Simms did not tell her to do so, or give her a requisition for it.

[60] Ms. Knight’s memory of who she spoke to during her various hospital visits, and what they told her, was generally poor. This is understandable in the circumstances, but leaves me unsatisfied that her positive present memory that Dr. Simms never gave her a blood work requisition is reliable. I prefer the documentary evidence that shows that Dr. Simms requisitioned the blood work, and I find it to be more likely than not that he then gave the requisition to Ms. Knight, and that she then forgot about it.

E. Ms. Knight’s return to hospital on February 18, 2014

[61] Ms. Knight testified that when she was discharged from the hospital the day after her surgery she was still in some pain, but that she expected this and assumed it would improve. However, over the next few days the pain in the right side of her abdomen became worse, and she began feeling weaker and sicker. Eventually, on the evening of February 18, 2014, which was five days after her surgery, she went to the emergency room at the Royal Victoria Hospital of Barrie. She went to RVH rather than returning to Stevenson because it was closer to her home.

[62] The RVH emergency room doctors requisitioned a CT-scan with contrast. The radiologist who reviewed the images, Dr. Jennifer Tynan, prepared a report in which she noted in her “findings” section that:

There is a phlegmonous fluid and air collection with developing peripheral enhancement in the pelvis measuring 5 × 3 cm which contacts the sigmoid colon and distal right ureter. There is proximal right hydroureter and severe hydronephrosis, renal enlargement and perinephric stranding with peripheral enhancement of the right renal collecting system. There is decreased enhancement of the right kidney as compared to the left. The right renal artery and vein are patent.

[63] Dr. Tynan also noted that there was “no left hydronephrosis”. She summarized her “impressions” as follows:

5 cm developing abscess in the pelvis. This contacts the right ureter, sigmoid colon and ileum. Severe right hydronephrosis with decreased renal enhancement in which pyelonephritis cannot be excluded.

[64] Some of the medical terminology in Dr. Tynan’s report requires further explanation:

• “Proximal right hydroureter” means that the right ureter was distended around the point where it joins the kidney;

• “hydronephrosis” is a swelling of the right kidney due to the buildup of urine;

• An abscess is a painful collection of pus that is usually caused by a bacterial infection;

• Pyelonephritis is an inflammation of the kidney and the lining of the “renal pelvis”, which is the part of the kidney where urine collects and is funneled into the ureter. It is often caused by a bacterial infection.

[65] Dr. Tynan’s findings and observations suggested that something was preventing urine from draining into Ms. Knight’s bladder through her right ureter, which in turn was causing the right kidney and top of the right ureter to become distended. As I will discuss later, the expert witnesses disagree about the extent to which these imaging observations suggested that Ms. Knight had a ureteric injury.

F. Ms. Knight’s transfer to Stevenson Memorial on February 19, 2014

[66] Ms. Knight stayed at RVH overnight. The next day, February 19, she was transferred back to Dr. Lawson’s care and taken by ambulance to Stevenson Memorial.

[67] RVH documents indicate that the transfer was arranged by an RVH gynecologist named Dr. Jan Moreau. The RVH “Emergency Report” chart states that a doctor in emergency reviewed the CT scan and “discussed with Dr. Moreau” at “0720”. Another document titled “Physicians Orders” directs Ms. Knight to be transferred to Stevenson Memorial Hospital “to see Dr. Lawson in ER”, describing this as a telephone order received from Dr. Moreau. However, the documents do not indicate if Dr. Moreau ever saw Ms. Knight personally, or whether he personally reviewed Dr. Tynan’s CT scan report, as opposed to merely discussing it with the emergency room doctor.

[68] There is also conflicting evidence about whether Ms. Knight’s inter-hospital transfer was unusual. Dr. Browning and Dr. Casey testified that in their experience it would be normal to transfer a patient with post-surgical issues back to the care of the physician who had performed the surgery, but Dr. Lawson testified that she had only seen this done when the patient was being transferred to a doctor at the same hospital.

[69] Dr. Lawson testified that she had a telephone conversation with Dr. Moreau before Ms. Knight arrived back at Stevenson. She would not yet have seen any of the medical records from RVH, since these would have come with Ms. Knight in the ambulance. Dr. Lawson recalled that all Dr. Moreau told her is that “the patient was being transferred back for abscess”. She explained in her testimony in chief that if Dr. Moreau had said anything about Ms. Knight having a suspected ureteric injury: “I would not have accepted her because we [did] not have urology service” at Stevenson Memorial, and would instead have recommended that Ms. Knight remain at RVH, which had urologists on staff. At a later point in her evidence in chief Dr. Lawson noted:

[M]y other thought was that if he thought the patient … could not be taken care of at Stevenson, it's unlikely that he would have transfer[red] a patient … to Stevenson that could not be taken care of there.

[70] After Ms. Knight arrived at Stevenson Memorial, Dr. Lawson received a “request for medical consultation” from the physician who first saw her in emergency, Dr. Ozon. At this point she would have received and reviewed Dr. Tynan’s CT scan report, although she did not see the image scans themselves.

[71] Dr. Lawson made a note on the consultation form in which she summarized Ms. Knight’s presentation, and stated: “CT revealed severe hydronephrosis. Possible pyelonephritis vs. abscess”. In cross-examination, she explained that her belief at the time was that the hydronephrosis noted in the CT scan report could be caused by “mass effect, so if there was [an] abscess compressing the ureter”, or that it could also be caused by pyelonephritis, which is an inflammation of the kidney. Dr. Lawson explained further:

I did not consider ureteric injury because we had seen the ureters. And, so that was why that was not on the differential.

[72] Ms. Knight had already been prescribed one antibiotic while at RVH, and Dr. Lawson prescribed two additional antibiotics, one that was directed at managing the possible abscess and the other at managing the possible pyelonephritis.

G. Ms. Knight’s discharge from Stevenson Memorial Hospital on February 23, 2014

[73] Ms. Knight remained at Stevenson Memorial for the next four days, during which time her symptoms improved. Dr. Lawson made a note on February 21, 2014 in which she indicated that Ms. Knight was “feeling better”, and set out her plan to continue treating Ms. Knight with antibiotics for “pyelonephritis/abscess”. On February 22, 2014 RVH faxed a report to Stevenson Memorial indicating that tests conducted on a sample of Ms. Knight’s urine that was taken before her transfer three days earlier showed the presence of bacteria.

[74] On February 23, 2014, Ms. Knight told the nurses that she wanted to go home. Dr. Lawson was consulted by phone, and ordered that Ms. Knight be discharged. In her discharge summary she noted that Ms. Knight’s white blood cell count, which had previously been high, consistent with her having an infection, had now gone down to normal levels. Dr. Lawson discontinued Ms. Knight’s antibiotic treatment and directed her to return in a week for a “follow up CT scan”, explaining at trial that the purpose of the CT scan was to “look for resolution of the hydroureter as well as [the] abscess”.

H. Ms. Knight returns to Stevenson Memorial (March 3, 2014)

[75] Ms. Knight remained out of the hospital for the next week, but on March 3, 2014, eight days after her discharge on February 23, and eighteen days after the February 13 surgery, she returned to the Stevenson Memorial emergency room and was readmitted. She testified that she had started feeling pain and nausea again within a day of her February 23 discharge. However, Dr. Lawson’s note made after Ms. Knight’s readmittance to the hospital stated: “Patient did well until one day ago”.

[76] An ultrasound imaging exam conducted on March 3 showed that Ms. Knight had ascites – an accumulation of fluid in the abdomen – which had not previously been present. The amount of fluid was measured as 700 millilitres. Dr. Lawson arranged for Ms. Knight to have a CT scan the next morning, on March 4, which was the earliest this could be conducted at Stevenson Memorial.

[77] The radiologist who conducted the CT scan the next morning, Dr. Bruno, called Dr. Lawson immediately to report that the scan showed urine leaking from Ms. Knight’s right ureter. At this point Dr. Lawson realized that Ms. Knight had a ureteric injury and needed to be seen and treated by a urologist. She proceeded to make arrangements for Ms. Knight to be transferred to Southlake Regional Health Centre and put in the care of a urologist, Dr. Steve Kim, who agreed to receive her.

[78] Ms. Knight testified that she had “no control over my bladder by this point”. The two expert witness urologists explained that what Ms. Knight thought was a loss of bladder control was actually urine that was leaking out of her right ureter, bypassing her bladder; pooling in her pelvis, and then draining out through the sutured end of her vagina. In medical terms, this is referred to as a “ureterovaginal fistula” or a “ureteral vaginal fistula”, meaning an abnormal connection between her ureter and her vagina through which urine can travel.

I. Ms. Knight’s treatment at Southlake

[79] After Ms. Knight was transferred to Southlake a drainage catheter was inserted into her bladder. The following day, on March 5, 2014, Dr. Kim performed an imaging test called a “retrograde pyelogram”, in which he injected radio-opaque dye into her right ureter from her bladder. The test showed that Ms. Knight’s right ureter was leaking approximately 5 centimetres from where it meets the bladder, but that the ureter was not completely severed, since dye was also flowing further up past the leak. After performing this test, Dr. Kim was able with some difficulty to place a stent in Ms. Knight’s right ureter. He concluded his operative note by observing that “[t]his patient certainly has a right ureteric injury”, and adding optimistically: “Hopefully, the leak and injury will heal over the stent”.

[80] Dr. Buckley explained that a ureteric stent is different from a coronary stent, in that it does not expand to press against the side of the ureter’s wall, and is also perforated with holes. While some urine will flow down the inside of the stent once it is in place, placing the stent in the ureter causes the ureter to dilate significantly, and a considerable amount of urine continues to flow outside the stent, between the stent and ureteral wall. Accordingly, Dr. Kim’s successful placement of the stent on March 5 did not stop Ms. Knight’s right ureter from leaking, nor was it expected to, although he hoped stenting would reduce the flow of urine into her abdominal cavity and also help the injury heal.

[81] Ms. Knight was discharged from hospital the next day, at which point urine appears to have stopped leaking from her vagina. Unfortunately, the stent did not permanently relieve Ms. Knight’s symptoms, and she continued to have fevers, and urine once again began leaking out of her vagina uncontrollably. In a March 18, 2014 note summarizing Ms. Knight’s follow-up appointment, Dr. Kim commented that Ms. Knight was continuing to have “some leakage of fluid”. The catheter in her bladder was also “causing her significant discomfort”, so Dr. Kim removed it.

[82] On March 26, 2014 Dr. Kim performed another retrograde pyelogram that showed that urine was still leaking out of Ms. Knight’s right ureter, collecting in her abdomen, and draining out through her vagina. He also reinserted a catheter into her bladder during this procedure. Dr. Kim’s operative notes conclude by stating:

I will make arrangements for a drainage and possible further diversion with a nephrostomy tube. If things do not resolve, she will require surgical ureter repair and reimplantation.

[83] On March 28, 2014, Ms. Knight had a further medical procedure in which a nephrostomy tube was inserted to drain urine from her right kidney, and a catheter was installed in her abdomen to drain the collected urine and pus. Dr. Casey and Dr. Buckley both explained that the purpose of the nephrostomy tube was to try to drain urine from Ms. Knight’s right kidney and stop as much of it as possible from flowing down her right ureter, while the abdominal drain was meant to prevent urine that leaked out of her right ureter from collecting in her abdomen. Dr. Buckley explained that urine is “a very, very, toxic substance to the abdominal cavity, and that when urine pools in the abdomen and drains out through a patient’s vagina, bacteria can enter the patient’s abdomen through the same route, causing an infection. Dr. Casey described the process of having a nephrostomy tube inserted as “not a lot of fun” for the patient, while Ms. Knight described the experience as “horrible”.

[84] Ms. Knight was discharged from Southlake on March 31, 2014, with the three drainage catheters – in her right kidney, her bladder, and her abdomen, respectively – still in place. Ms. Knight found the experience of living with drainage tubes and bags uncomfortable and humiliating, and had to have nurses come in to change the bags. Nevertheless, after the drainage tubes were installed her condition improved, and when Dr. Kim saw her for a follow-up appointment on April 8, 2014 he noted that she was doing “quite well” and “feeling much better.”

[85] On April 30, 2014 Dr. Kim performed another retrograde pyelogram imaging test on Ms. Knight, which showed that “[u]nfortunately, there is a very tiny opening still, in the right distal ureter, communicating with the vagina”. Dr. Kim concluded his operative note by observing:

Unfortunately, this patient despite maximal diversion drainage continues to experience persistent ureteral vaginal fistula, and this has not healed. It has already been several weeks and therefore it is doubtful and unlikely that this will heal on its own with conservative measures. I did discuss with her that we will likely require an open ureteric repair with possible reimplantation and fistula closure.

During a follow-up appointment on May 6, 2014 they discussed scheduling the repair operation for June or July.

[86] Dr. Kim ultimately performed the repair and reimplantation on June 20, 2014. During the surgery he was able to identify a “small ureteric injury” on the right ureter near Ms. Knight’s bladder. After performing the reimplantation Dr. Kim made a number of observations that he found “reassuring”. He concluded his operative note optimistically by stating: “I am hoping that this will successfully get Ms. Knight dry and no longer have further infections”.

[87] Dr. Casey explained that reimplantation surgery is a significant operation that typically takes three or four hours under general anaesthesia. It is done openly rather than laparoscopically, and:

… requires quite a large abdominal incision. The site of the injury has to be identified and closed, and the ureter has to be inspected and sometimes reimplanted if it’s been damaged.

During his trial testimony Dr. Buckley adopted a passage from his report where he had explained that this surgery:

… can be performed in the first couple of days following abdominal or pelvic surgery if it is recognized but once this time period has occurred it is wiser to wait until the pelvic field has settled down and healed. This typically would be a minimum of two months following the original surgery.

In Ms. Knight’s case the delay was slightly more than three months.

[88] Ms. Knight was released from the hospital two days after the June 20, 2014 repair and reimplantation surgery, and slowly began to recover. She still had a ureteric stent in her right ureter and a Foley catheter in her bladder. When she returned for further imaging on July 2, 2014, Dr. Kim noted that she had a “small ureteric anastomotic leak” which had not yet healed, and commented: “I fear that she has had ongoing problems with catheter drainage and therefore is not decompressing as nicely and healing properly”.

[89] Dr. Casey explained that this new ureteric leak was at the point where Ms. Knight’s right ureter had been surgically reconnected to her bladder, and that while it showed that she was “not out of the woods yet”, it was “not that worrisome”. However, the presence of this leak led Dr. Kim to decide to leave the ureteric stent and the bladder catheter in for another few weeks.

[90] When Ms. Knight returned for another follow-up examination a few weeks later, on July 23, 2014, her situation was improving and Dr. Kim decided to remove the catheter, but leave in the ureteric stent. He removed the stent a month later, on August 20, 2014, and noted that Ms. Knight “has had no further vaginal leaking, which is excellent”.

[91] By September 2014 Dr. Kim was declaring himself “quite satisfied with the overall outcome”, and noted that “[o]verall, the patient is happy”, although he noted that “[u]nfortunately, given her re-implantation, she really does have a freely refluxing ureter and collecting system”. Dr. Casey explained that patients who have ureteric reimplantation surgery lose the mechanism that prevents urine from flowing back up into the kidneys when the bladder contracts, which can put them at a higher risk of kidney infections.

[92] Ms. Knight continued to have occasional checkups with Dr. Kim for the next two years. In his final note, written after Ms. Knight’s final appointment on May 9, 2016, Dr. Kim noted that she had had “recurrent” kidney and urinary tract infections, but that “things have actually settled down for her for the most part”.

[93] Ms. Knight described the six month period between the February 13, 2014 operation and the final removal of the stent in August 2014, as an extremely difficult time for her. The drainage tubes and catheter were very uncomfortable, and she found them humiliating. They also interfered with Ms. Knight’s relationship with her boyfriend – now her husband – by preventing them from having sexual relations. Until the bladder catheter was finally removed, Ms. Knight also constantly felt a burning sensation when she urinated.

[94] Ms. Knight found herself unable to work full time during this period, although she tried to work from home when she was able. She ended up remaining off work until February 2015, which she attributed to “emotional stuff”, since by the fall of 2014 she was “physically feeling better”. When she eventually did return to work she could not bring herself to re-take the exam to qualify as a paralegal, which she had first taken but failed the day before her February 2014 surgery.

[95] However, Ms. Knight now seems to have made essentially a full recovery. She never did retake the exam to qualify as a paralegal, but eventually switched careers and now works at a cannabis facility, where she earns substantially more than she did in her old job as a law office receptionist. Her medical issues in 2014 did not have any lasting impact on her romantic relationship with her partner, and they married in 2017.

[96] Although Ms. Knight testified that her “bladder is still pretty weak” and she has to urinate frequently, she has not sought medical attention for this problem. I agree with the defence that there is no clear evidence in the record establishing that this latter problem is attributable to the 2014 ureteric injury and repair surgery. To the contrary, Dr. Hunter’s uncontradicted evidence was that this issue is common among women of Ms. Knight’s age who have similar risk factors (for example, having gone through childbirth and being a smoker).

III. Analysis

A. General Principles

[97] The parties are agreed on the general legal principles that govern actions for the tort of negligence, and that apply in the special context of alleged medical malpractice.

[98] As McLachlin C.J.C. observed in Mustapha v. Culligan of Canada Ltd., 2008 SCC 27, [2008] 2 SCR 114, at para 3:

A successful action in negligence requires that the plaintiff demonstrate (1) that the defendant owed him a duty of care; (2) that the defendant’s behaviour breached the standard of care; (3) that the plaintiff sustained damage; and (4) that the damage was caused, in fact and in law, by the defendant’s breach.

[99] In the case at bar, there is no dispute that Dr. Lawson, as Ms. Knight’s treating physician, owed her patient a duty of care. It is Ms. Knight’s burden to establish the three remaining essential elements of negligence, on a balance of probabilities.

[100] On the second essential element – whether Dr. Lawson breached the standard of care – it is well established that the standard of care in medical negligence cases is determined by reference to what should be expected of a reasonable physician with comparable expertise. As Sopinka J. explained in Ter Neuzen v. Korn, 1995 CanLII 72 (SCC), [1995] 3 SCR 674, at para 33:

It is well settled that physicians have a duty to conduct their practice in accordance with the conduct of a prudent and diligent doctor in the same circumstances. In the case of a specialist, such as a gynaecologist and obstetrician, the doctor's behaviour must be assessed in light of the conduct of other ordinary specialists, who possess a reasonable level of knowledge, competence and skill expected of professionals in Canada, in that field. A specialist, such as the respondent, who holds himself out as possessing a special degree of skill and knowledge, must exercise the degree of skill of an average specialist in his field …

[101] As a gynecologist, the adequacy of Dr. Lawson’s medical treatment of Ms. Knight must be measured against what should have reasonably been expected from a prudent and diligent gynecologist who had been faced with the same circumstances that confronted Dr. Lawson. She cannot properly be held to a standard of perfection, since even prudent and diligent specialist physicians sometimes make mistakes or commit errors of judgment.

[102] It is also an error to reason backwards and conclude that because a patient had a bad medical outcome, his or her treating physician must have been negligent. Some patients have unfortunate health outcomes even when they receive reasonably appropriate medical care.

[103] Moreover, Dr. Lawson’s medical decisions and judgment cannot be viewed through the lens of hindsight, but must be assessed from the perspective of what would have been known to a reasonable specialist in her position. Doctors are not omniscient, and they often have to make tentative diagnoses and treatment choices based on substantially incomplete information. Their decisions cannot fairly be criticized on the grounds that they were not aware of facts that no doctor could reasonably be expected to have known at the time. To adopt an expression that was used throughout the trial, both by counsel and by some of the expert witnesses, a doctor’s conduct cannot be viewed using a “retrospectoscope”.

[104] Two further related points that bear mentioning are that the issues of standard of care and causation must be kept separate, and that the question of whether a defendant doctor breached the standard of care should ordinarily be considered first: see, e.g., Bafaro v. Dowd, 2010 ONCA 188, at para. 35; Armstrong v. Royal Victoria Hospital, 2019 ONCA 963, at paras. 60-61 (per Paciocco J.A.) and 138 (per van Rensburg J.A., dissenting); rev’d, 2021 SCC 1 (sub nom Armstrong v. Ward). As van Rensburg J.A. noted in Armstrong, dissenting in the result but giving reasons that were later adopted by the Supreme Court of Canada, at para. 138:

Determining standard of care before causation ensures that the trial judge does not wrongly reason backwards from the fact of the injury to determine that the standard of care has been breached.

However, she added that trial courts must sometimes:

… determine “what happened” (that is, the factual cause of the plaintiff’s injury) in order to resolve whether the standard of care has been breached. Determining factual (and not “but-for”) causation is sometimes necessary before a conclusion can be reached on whether there has been a breach of the standard of care.

B. Findings of fact regarding the cause of Ms. Knight’s ureteric injury

[105] In this case, I find it helpful to begin by addressing the question of how Ms. Knight’s right ureter came to be injured in the first place. To reiterate, she is not alleging that Dr. Lawson was negligent in causing this injury. However, as I will discuss, the probable nature of Ms. Knight’s ureteric injury is a highly relevant factor when assessing both of her alternative theories of liability. For this reason, I find it useful at the outset to consider the question of how the injury was caused.

[106] I am mindful of the cautions expressed in Armstrong about the pitfalls of determining issues of causation before addressing the issue of standard of care. However, this concern is reduced in this case, because Ms. Knight is not arguing that Dr. Lawson breached the standard of care when she injured Ms. Knight’s ureter during the February 13, 2014 operation.

[107] As I have already discussed, the medical expert witnesses identified three main mechanisms by which a patient’s ureters can be damaged during surgery.

[108] The first type of injury is a laceration-type injury, in which the wall of the ureter is cut by a sharp surgical instrument. Sometimes the ureter is completely transected, but it can also be lacerated without being completely severed.

[109] I am satisfied that the possibility of a laceration injury can be ruled out in this case, since if the wall of Ms. Knight’s right ureter had been cut during the February 13, 2014 operation, urine would have begun leaking out immediately. This evidently did not happen, since not only would Dr. Lawson and Dr. Simms almost certainly have seen it, but the CT scan that was conducted five days after the surgery, on February 18, 2014, showed that Ms. Knight’s right ureter was distended and her right kidney was swollen, but did not show any urine pooled in her abdomen. This strongly suggests that her right ureter was backed up due to some sort of blockage, but that it had not yet started to leak. Rather, the evidence indicates that Ms. Knight’s right ureter probably did not begin leaking until some time after her February 23, 2014 discharge from Stevenson Memorial, during the eight days prior to her readmittance on March 3, 2014.

[110] Importantly, none of the medical experts suggested that Ms. Knight’s symptoms and their progression were suggestive of a laceration-type injury. I have no hesitation treating this possibility as effectively ruled out by the evidence as a whole.

[111] The second mechanism, a ligation-type injury, involves the ureter being physically blocked by being squeezed in a surgical clamp or caught up in a loop of suture. Dr. Browning initially endorsed this mechanism as the most likely cause of Ms. Knight’s injury, testifying that he would “lean towards … some form of a suture accident, but it’s debatable”. However, later in cross-examination he acknowledged that he was really not sure how Ms. Knight’s injury had been caused, and questioned whether anyone could really make this determination, testifying:

Well, the reality is the nature of the injury is going to be a guess. Unless you visualize it operatively … it’s just a guess. It’s your best guess.

[112] The third possibility is that Ms. Knight suffered some form of ischemic devascularization injury, in which the blood supply to the wall of her right ureter was cut off, causing the tissue or the ureteral wall to eventually die, which over time led to it rupturing and leaking urine. Dr. Hunter, Dr. Casey and Dr. Buckley were all of the opinion that this was the most likely mechanism of injury in Ms. Knight’s case.

[113] On all the evidence, I agree with the majority expert view that the ischemic devascularization scenario is considerably more likely than any of the alternatives.

[114] For a number of reasons, I think that this possibility is substantially more likely than the alternative possibility that Ms. Knight suffered a ligation-type injury, which was at least initially favoured by Dr. Browning.

[115] There is no evidence that Dr. Lawson used any surgical clamps during the operation, and her unchallenged testimony was that she did not use any sutures during the laparoscopic part of the procedure, and used only one suture during the second vaginal part of the operation. Dr. Buckley described this suture as “in the right cul-de-sac, which is deep down in the pelvis”. While it might perhaps be possible that this single suture became looped around Ms. Knight’s right ureter, Dr. Hunter, Dr. Casey and Dr. Buckley all thought it was more likely that the blood supply to her ureter was thermally damaged by the device Dr. Lawson had used during the operation to cauterize blood vessels.

[116] During his trial testimony, Dr. Buckley adopted the comments he made in one of his reports, where he had explained:

I have personally managed more than 100 of these types of cases. In my experience, ureteral ischemia secondary to coagulation from a thermal injury is by far the most likely cause of ureterovaginal fistulas. These patients typically present 1-2 weeks postoperatively. The pathophysiology is that the cautery causes ischemia to the ureter. There is subsequent swelling which causes obstruction. The ureteric tissue then breaks down in that 1-2 week postoperative period. The urine then leaks into the abdomen and eventually through the vaginal cuff, creating a ureteral vaginal fistula.

[117] Dr. Casey agreed with Dr. Buckley’s opinion on this point, stating that he also considered it “likely” that Ms. Knight had suffered an “ischemic surgical injury”. The defence gynecologist, Dr. Hunter, was of the same opinion, testifying:

[I]n my opinion it was likely related similar to Dr. Buckley’s opinion to some type of ischemic or vascular injury to the ureter itself that presented with a sort of delayed presentation. And that would be based on the history of the chronology of what happened in this case.

[118] As I have already noted, the fourth expert witness, Dr. Browning, initially favoured the ligation-type injury scenario but later clarified that in his opinion there is simply no way to tell what caused Ms. Knight’s injury.

[119] I accept the expert’s majority view that a thermal ischemic injury is the most likely explanation for Ms. Knight’s injury. It fits the progress and timing of her presentation and symptoms far better than any of the other alternatives, particularly after taking into account Dr. Lawson’s uncontradicted evidence that she used only one suture during the vaginal part of the procedure, and that she used a thermal cauterization device throughout the operation.

C. The plaintiff’s first theory of liability

[120] It is undisputed that Dr. Lawson did not observe anything wrong with Ms. Knight’s ureters while she was performing the February 13, 2014 operation. The plaintiff’s first theory of liability is that Dr. Lawson ought to have spotted the problem, and was negligent in failing to do so.

1. Did Dr. Lawson fail to meet the duty of care by not detecting Ms. Knight’s ureteric injury intraoperatively?

[121] Ms. Knight’s argument that Dr. Lawson was negligent in failing to detect the injury to Ms. Knight’s right ureter during the February 13, 2014 surgery has two main evidential planks.

[122] First, she points to the absence of any mention by Dr. Lawson in her operative notes that she checked Ms. Knight’s ureters at the conclusion of the operation. Dr. Lawson initially testified that she had checked Ms. Knight’s ureters, but she later acknowledged that she really had no specific memory of performing this particular surgery, and that her belief that she had checked Ms. Knight’s ureters was based on what was her ordinary practice.

[123] Second, Ms. Knight relies on Dr. Browning’s opinion that “if you checked the ureter properly you would have typically seen an injury”. She argues that because Dr. Lawson did not see an injury to Ms. Knight’s right ureter, it can be inferred that Dr. Lawson must have failed to check her ureters properly.

[124] The defence disputes both of these claims. According to the defence, there is no good reason to doubt Dr. Lawson’s evidence that she checked Ms. Knight’s ureters according to her usual practice, even though she did not specifically note this in her postoperative report. Moreover, the defence contends that it is unlikely that a thermal ischemic injury to Ms. Knight’s right ureter would have been visually observable during the operation.

[125] As I will now explain, I think the evidence supports Dr. Lawson on both of these points.

[126] I should note at the outset that there is no dispute between the parties that the standard of care requires doctors performing this type of operation to check the ureters both at the start and at the end of the procedure. The reason for this is clear. Surgical ureteric injuries, while not common, are serious. Identifying the ureters at the start of the procedure reduces the risk of damaging them accidentally, and examining them at the end to look for possible injuries is a sensible precaution for surgeons to take even though, as I will discuss, not all injuries will necessarily be visible.

[127] Dr. Lawson agreed that the standard of care required her to conduct both checks. She testified that she had been trained to do them, and that her usual practice was to do them in accordance with her training. The main disputed issue in relation to this theory of liability is whether it can be concluded on the evidence as a whole that Dr. Lawson probably failed to follow her usual practice when she operated on Ms. Knight on February 13, 2014. It is Ms. Knight’s burden to affirmatively establish on a balance of probabilities that Dr. Lawson did not perform a proper visual check of her ureters at the end of the February 13, 2014 operation.

[128] Ms. Knight argues that the absence of any mention in Dr. Lawson’s post-operative report that she checked Ms. Knight’s ureters is circumstantial evidence that she did not check them. However, Dr. Lawson’s evidence was that it was not her usual practice to include this detail in her post-operative notes, and that it cannot be inferred that because she did not specifically mention doing it, she must not have done it.

[129] Dr. Lawson’s evidence about her usual note-taking practices stands uncontradicted. Dr. Browning initially attached significance to the fact that the postoperative report from the earlier surgery Dr. Lawson had performed on Ms. Knight in 2013 did mention checking her ureters, but he had not realized that even though Dr. Lawson signed this note, it was actually dictated by her surgical assistant, Dr. Simms.

[130] Post-operative reports cannot realistically be a complete play-by-play commentary of everything that happened during an operation. Physicians who prepare these reports must inevitably make editorial choices about which details to include and which to omit. Different doctors are likely to have different practices when making these choices. I do not think that Dr. Simms’s mention of checking Ms. Knight’s ureters in the 2013 report that he dictated, and which Dr. Lawson then signed, stands against her evidence that she did not usually include this detail when she prepared post-operative reports herself.

[131] There is no basis for me to reject Dr. Lawson’s evidence about her usual report-writing practice. It follows that I cannot treat the absence of any specific mention of checking Ms. Knight’s ureters in Dr. Lawson’s February 13, 2014 report as evidence that she did not follow her usual practice of checking her patient’s ureters on this occasion.

[132] I find it unnecessary to decide whether gynecologists ought to specifically note in their post-operative reports of pelvic surgery that they performed ureter checks, as Dr. Browning suggested in his testimony. Even if I were to treat Dr. Lawson’s failure to include this detail in her February 13, 2014 report as a breach of the standard of care, it was not a breach that caused any direct harm to Ms. Knight, if Dr. Lawson really did properly check Ms. Knight’s ureters. Any omission by Dr. Lawson in documenting having done so after the fact would not have adversely affected Ms. Knight’s health or her subsequent medical treatment.

[133] It is undisputed that Dr. Lawson did not observe the injury to Ms. Knight’s right ureter that Ms. Knight was later found to have. However, I do not think this supports the inference that Dr. Lawson must not have conducted a proper visual check.

[134] It is clear from all of the evidence that some types of ureteric injuries are much easier to visually identify than others.

[135] If Dr. Lawson had accidentally transected or lacerated Ms. Knight’s right ureter, causing urine to immediately start leaking out, she and Dr. Simms very likely would have noticed this during the operation, even before they conducted any final visual check of Ms. Knight’s ureters. I accept that if they had failed to notice such an injury they would have fallen below the standard of care, but as I have already discussed, the evidence strongly weighs against Ms. Knight having suffered a laceration-type injury.

[136] If Dr. Lawson had accidentally looped a suture around Ms. Knight’s right ureter, I accept that this would also have been something that she probably could and should have spotted during a proper visual check. However, as I have already discussed, I find it much more likely that Ms. Knight suffered a thermal ischemic injury, and not a ligation-type injury.

[137] There was conflicting evidence from the experts about whether a thermal ischemic injury would be visible during an operation. Dr. Browning testified that a thermal injury could cause “charcoal coloured … discoloration” to the ureter, which he thought would be visually observable. However, he acknowledged that he had never dealt with such an injury personally.

[138] Dr. Hunter’s contrary opinion was that a thermal ureteric injury was “not something you would really be able to notice” intraoperatively. He explained:

[T]he ureter would look totally normal at that particular time. …[I]t takes time for the devascularization to occur from the thermal injury and then subsequent breakdown of the ureter.

[139] I prefer Dr. Hunter’s opinion on this issue. While I accept that it is possible for a patient’s ureter to be burned so severely that it turns “charcoal coloured”, as Dr. Browning described, I accept Dr. Hunter’s evidence that a doctor who is cauterizing a blood vessel during an operation will not “necessarily be able to tell” if the heat from the cauterization tool “went too far lateral to cause any damage to another structure”.

[140] In this regard, it is important to bear in mind the mechanism of injury described by Dr. Hunter, Dr. Casey and Dr. Buckley involves thermal damage to the blood vessels that connect to and supply the ureter, not direct thermal damage to the tissues of the ureter itself. As I understood their evidence, these blood vessels can be damaged without necessarily burning the ureter itself, and certainly without burning it so severely that it turns black. While I accept that it may be possible to burn the ureter so severely that it carbonizes, I am not satisfied that this is something that happens every time there is a thermal injury to the blood vessels that results in ischemia, or that such a severe burn is even likely.

[141] I would add that the evidential basis for Dr. Browning’s stated opinion that “you would see, like a charcoal typical type of look where you clearly cauterized the ureter” is unclear, since he acknowledged that he had never personally dealt with any thermal ureteric injury cases. His opinion is also beside the point, since there is no evidence that Dr. Lawson “clearly cauterized the ureter” during the operation. Rather, the evidence strongly suggests that she cauterized the blood vessels supplying the ureter, not the ureter itself.

[142] I am accordingly not prepared to draw the inference that Dr. Lawson’s failure to observe the injury to Ms. Knight’s right ureter means that she must have failed to conduct a proper visual check. To the contrary, I accept Dr. Hunter’s evidence on this point, and find that it is more likely than not that Ms. Knight’s ureteric injury would not have been visible at the time of the surgery.

[143] It follows that I am not persuaded that there is any circumstantial evidence that weighs against Dr. Lawson’s testimony that she probably followed her usual practice and checked Ms. Knight’s ureters.

[144] While I find Dr. Lawson to be a generally credible witness, she frankly acknowledged that she no longer has any real recollection of performing this particular operation. This is hardly surprising, since Ms. Knight’s operation occurred many years ago, and was a procedure Dr. Lawson has performed many other times during her medical career. Accordingly, Dr. Lawson’s testimony leaves open the possibility that she could have failed to follow her usual practice on this particular occasion.

[145] However, I do not find this possibility very likely, for three main reasons.

[146] First, as a matter of common sense, it would be somewhat surprising for an experienced doctor like Dr. Lawson not to follow her training and established practice when performing an operation that she had performed many times before. It is certainly possible, since even experienced doctors sometimes make mistakes, but in the absence of any affirmative evidence that this happened, it is not something I would characterize as probable.

[147] Second, Dr. Lawson did not perform the operation alone, but was assisted by Dr. Simms, who is also an experienced gynecologist. They had operated together many times before. It strikes me as implausible that they would have both simultaneously have forgotten to take the basic step of performing a visual check of Ms. Knight’s ureters at the end of the procedure. If Dr. Lawson for some reason forgot, I think it is more likely than not that Dr. Simms would have reminded her.

[148] Finally, Dr. Simm’s discharge notes to some extent confirm Dr. Lawson’s evidence that she would have followed her usual practice and checked Ms. Knight’s ureters. In the course of noting Ms. Knight’s slightly elevated creatinine levels, Dr. Simms specifically commented: “There was no problem with her ureters at the time of the procedure.”

[149] Dr. Simms wrote this note the day after the surgery, and was plainly turning his mind to the possibility that Ms. Knight’s elevated creatinine levels could be an early sign of a ureteric injury. If he and Dr. Lawson had both forgotten to check Ms. Knight’s ureters at the end of the surgery, I think it is likely that once the possibility of a ureteric injury occurred to Dr. Simms the next day he would have realized their mistake, and would have ordered further tests, rather than discharging Ms. Knight with a note in which he dismissed the prospect of a ureteric injury as unlikely.

[150] In summary, I am not persuaded that Dr. Lawson failed to check Ms. Knight’s ureters at the conclusion of the February 13, 2014 operation. To the contrary, I find it more likely than not that Dr. Lawson did properly check Ms. Knight’s ureters, but failed to see the injury to her right ureter because it was not visually observable at the time.

2. Did any failure by Dr. Lawson to properly check Ms. Knight’s ureters cause Ms. Knight any harm?

[151] Having found that Ms. Knight has not affirmatively established any intraoperative breach of the standard of care by Dr. Lawson, it is not strictly necessary for me to consider the issue of causation in relation to any such alleged breach. However, I will do so briefly.

[152] Even if Dr. Lawson did fail to perform a proper visual check of Ms. Knights ureters, contrary to my finding of fact, I am not satisfied that this caused Ms. Knight to suffer a worse medical outcome.

[153] As I have already explained, I have found that it is more likely than not that Ms. Knight’s injury was a thermal ischemic injury, which probably would not have been visible to Dr. Lawson intraoperatively. Accordingly, even if I had found that Dr. Lawson had failed to conduct a proper visual check of Ms. Knight’s ureters – contrary to my actual finding of fact – I would not have been satisfied on a balance of probabilities that a proper visual check would have allowed her to notice the injury. I would accordingly not have been prepared to find that Ms. Knight had met her burden on the issue of causation in relation to her first theory of liability.

[154] The parties also dispute the question of causation on a different footing. Specifically, the defence argues that even if Dr. Lawson had noticed Ms. Knight’s ureteric injury intraoperatively, this would not likely have led to a different or better outcome for her, because it would still not have been possible to perform the repair surgery for several months.

[155] There is some overlap between this issue and the causation issue that arises from the plaintiff’s second theory of liability. However, Dr. Buckley’s evidence weighs against the defence on this point. As I have already noted, he testified that ureteric repair and reimplantation:

can be performed in the first couple of days following abdominal or pelvic surgery if it is recognized but once this time period has occurred it is wiser to wait until the pelvic field has settled down and healed. This typically would be a minimum of two months following the original surgery.

[156] If Dr. Lawson had somehow managed to identify the injury to Ms. Knight’s right ureter during the February 13, 2014 operation, I agree with the defence that she would not have been able to repair it immediately herself while Ms. Knight was still on the operating table. She is not a urologist; there were no urologists on staff at Stevenson Memorial; and the repair and reimplantation procedure could not have been performed laparoscopically in any event. Accordingly, I agree with the defence that Dr. Lawson’s only recourse in this scenario would have been to finish the LAVH procedure and transfer Ms. Knight to a hospital that had urological services.

[157] It is not entirely clear from the evidence what would have happened if a urologist had received Ms. Knight into his or her care a day after the LAVH procedure, knowing that she had suffered a thermal ischemic injury to her right ureter that would probably cause the ureter to start leaking in the coming weeks, but that it was not yet leaking now.

[158] However, in view of Dr. Buckley and Dr. Casey’s evidence that thermal ischemic injuries are unlikely to heal on their own, even with early stenting – an issue I will return to later – I think it is more likely than not that a urologist would not have let the narrow window for performing early repair and reimplantation surgery pass, and accordingly would have performed this operation on Ms. Knight or about February 14, 2014. If this had happened, Ms. Knight would have avoided at least several months of extremely unpleasant waiting to have this same surgery later. Moreover, if she had not gone through the psychological distress caused by having tubes implanted in her for months, and urine leaking uncontrollably out of her vagina, I think there is at least some reasonable prospect that she would not have required as much time off work.

[159] That said, this scenario is entirely hypothetical, and in my view unlikely to have ever materialized. As I have already explained, I think it is more likely than not that Dr. Lawson did properly check Ms. Knight’s ureters at the conclusion of the February 13, 2014 operation, and that she did not notice the nascent injury to Ms. Knight’s right ureter because it was not yet visually observable. While I accept that Ms. Knight would probably have been better off if her injury could have been identified intraoperatively, I think that the probable nature of her injury made the possibility of intraoperative detection unlikely, no matter how carefully Dr. Lawson performed her visual checks.

3. Conclusions on Ms. Knight’s first theory of liability.

[160] In summary, I find that Ms. Knight has not met her burden of establishing her first theory of tort liability, namely, an intraoperative breach of the standard of care by Dr. Lawson. I find that it is more likely than not that Dr. Lawson did perform a proper visual check of Ms. Knight’s ureters at the conclusion of the February 13, 2014 surgery, and accordingly did not fall below the standard of care. Moreover, even if Dr. Lawson did fail to perform a proper check, I find it more likely than not that this made no difference to Ms. Knight’s subsequent treatment and outcome, because I find that her ureteric injury was probably of a type that would not have been visually observable on that date.

D. Ms. Knight’s second theory of liability

[161] Ms. Knight’s alternative theory of liability is that when she returned to Stevenson Memorial Hospital on February 19, 2014, six days after her surgery, Dr. Lawson failed to meet the standard of care by not considering the possibility that her patient might have a ureteric injury, and by not consulting a urologist.

[162] Ms. Knight argues that if a urologist had been consulted at this point, this would probably have resulted in a stent being placed in her right ureter approximately two weeks earlier than actually happened. She contends further that earlier stenting would probably have resulted in a better outcome for her.

[163] Dr. Lawson’s position on this theory of liability is twofold. First, she argues that she did not fall below the standard of care when she decided to treat Ms. Knight on the basis that Ms. Knight probably had some form of infection, without also considering the possibility that her right ureter might have been injured during the February 13 surgery. Although it is now undisputed that Ms. Knight did have a right ureteric injury, as well as probably having an infection, Dr. Lawson contends that based on what she knew on February 19 it was not unreasonable for her to fail to include the possibility of a ureteric injury in her differential diagnosis.

[164] Dr. Lawson argues further that even if she was negligent by not considering this possibility, and even if an earlier urological consultation would have led to Ms. Knight’s right ureter being stented sooner, this would likely not have made any difference to Ms. Knight’s subsequent presentation and treatment. Her right ureteric injury is unlikely to have healed on its own even with earlier stenting; Ms. Knight would probably still have needed to have it surgically repaired and reimplanted; and this surgery could not have been performed any earlier even if Ms. Knight’s ureter had been stented two weeks earlier.

[165] As I will now explain, I have concluded that Dr. Lawson was negligent by not even considering the possibility of Ms. Knight having a surgical ureteric injury on February 19, 2014. Had she done so, I think it is more likely than not that she would have consulted with a urologist, and that this would have probably led to a stent being placed in Ms. Knight’s right ureter within the next few days, rather than two weeks later, on March 5.

[166] However, I am not satisfied that earlier stenting would have made any real difference in this case. To the contrary, I find that it is more likely than not that Ms. Knight’s presentation and treatment would have been essentially the same. The thermal ischemic injury to her right ureter was unlikely to have healed on its own even with earlier stenting, and she still would have required repair and implantation surgery, which could not have been conducted feasibly and safely any earlier than it was, even if the injury had been detected two weeks sooner.

[167] Accordingly, although I find that Ms. Knight has met her burden of establishing negligence, her second theory of liability fails under the causation branch of the analysis.

1. Did Dr. Lawson breach the standard of care by not considering the possibility of ureteric injury on February 19, 2014?

a) The evidence

[168] The first question that I must consider is whether Dr. Lawson fell below the standard of care when Ms. Knight came back under her medical care on February 19, 2014, and Dr. Lawson did not consult with a urologist about the possibility that Ms. Knight might have a ureteric injury.

[169] The question of what a reasonable and prudent gynecologist would have done in the situation Dr. Lawson found herself in must be determined based on what Dr. Lawson knew at the time, or could reasonably have known. Accordingly, it is helpful to begin by recapping the information that was available to her on February 19, 2014, when Ms. Knight was transferred from RVH to Stevenson Memorial and came back under Dr. Lawson’s care.

[170] It was now six days after Ms. Knight’s surgery. She had been discharged on February 14, 2014 with slightly elevated creatinine levels that had been sufficiently concerning to Dr. Simms to cause him to order follow-up blood tests to be done “in the next one or two days”, but had not alarmed him unduly. Ms. Knight had then failed to have these blood tests done.

[171] Ms. Knight had then returned to the hospital five days later, on February 18, 2019, feeling ill and complaining of abdominal and flank pain. A CT scan showed what the radiologist, Dr. Tynan, reported was “a developing abscess” in Ms. Knight’s lower pelvis that was contacting her right ureter. There were also observable problems with her right ureter and right kidney: the kidney was badly swollen (“severe hydronephrosis”), and her right ureter was distended around the point that it emerges from the kidney (“proximal right hydroureter”).

[172] Dr. Lawson received Dr. Tynan’s report as part of the documentation that would have been sent in the ambulance with Ms. Knight when she was transferred from RVH to Stevenson Memorial Hospital. Dr. Lawson also recalled that before Ms. Knight arrived at Stevenson, and thus before she would have seen Dr. Tynan’s report, an RVH gynecologist, Dr. Jan Moreau, had telephoned her to say that Ms. Knight “was being transferred back for abscess”.

[173] After Dr. Lawson reviewed the CT scan report that arrived with Ms. Knight, she settled on a differential diagnosis of “possible pyelonephritis vs. abscess”, and put Ms. Knight on a course of antibiotics that was meant to address both of these potential problems.

[174] In essence, Dr. Lawson assumed on February 19, 2014 that Ms. Knight’s distended right ureter and swollen kidney were secondary symptoms of an infection, but did not turn her mind to the alternative possibility that Ms. Knight had a surgical injury to her right ureter that was blocking the flow of urine to her bladder and causing it to back up in her right kidney, resulting in the distention and swelling of the right ureter and kidney that Dr. Tynan had noted in her CT scan report.

b) The expert opinions

(1) Dr. Browning

[175] The plaintiff’s expert witness gynecologist, Dr. Browning, believes that Dr. Lawson fell below the applicable standard of care by not considering the possibility of a ureteric injury, and by not seeking advice from a urologist. In his opinion, Dr. Lawson was:

focussed on treating either pyelonephritis or … an evolving abscess and really not focussed on what would have caused these findings in the first place or could have caused these findings in the first place and, and what is, you know, the problem with the hydronephrosis. It looks like there’s not much attention being paid to the hydronephrosis.

[176] In his view, given the combination of hydronephrosis, a dilated ureter, and recent gynecological surgery, the possibility “that there’s some kind of a ureteric injury that’s causing the hydronephrosis would be at the top of the differential diagnosis”, even if Ms. Knight could also have an infection. Dr. Browning explained:

[T]hese other things could …. also be occurring at, at the same time but they don’t relinquish the fact that this lady has … a severely dilated ureter … and the most likely reason for that is some kind of a ureteric injury, you know. … I would think even at this stage it would be appropriate to refer this woman to urology and have urology, you know, take a look at the situation and, and have a game plan for the dilated ureter.

[177] Dr. Browning found it “perplexing” that Dr. Lawson’s treatment plan did not directly address Ms. Knight’s hydronephrosis, but instead relied on the assumption that it was caused by an infection, such that treating the infection would make the hydronephrosis abate.

(2) Dr. Hunter

[178] The defence’s gynecological expert, Dr. Hunter, testified in chief that he thought Dr. Lawson’s decision to focus on Ms. Knight’s problems being caused by an infection was reasonable in the circumstances, emphasizing that there were:

other findings that are a little more consistent with infection and pyelonephritis and elevated white count. She had fever initially. Those things would all sort of go more in favour of infection which is, obviously, more common than ureteric injury.

[179] However, in cross-examination Dr. Hunter agreed with the following statements from a leading textbook, Te Linde’s Operative Gynecology:

Cautery devices must be used with care as the fusion of thermal energy can cause a cold ureteral injury resulting in delayed stricture or urine leak presenting days to weeks post-operatively. … And a high index of suspicion must be carried through the post-operative period to ensure early diagnosis and management if necessary.

He also acknowledged that based on Dr. Lawson’s notes from February 19, 2014, she “did not have a high index of suspicion for the problem [ureteric injury] at that time”.

[180] When counsel for the plaintiff suggested to Dr. Hunter that “it would have been reasonable and prudent to consider ureteric injury based on Ms. Knight’s presentation on February 19th”, Dr. Hunter responded:

I believe some physicians may have gone down that pathway of diagnosis and others may have been more swayed toward infection based on the information they had at hand at the time. So, in terms of standard of care, I don’t believe it is standard of care that everyone would have jumped to that conclusion immediately.

[181] However, Dr. Hunter agreed that the possibility of ureteric injury was “a consideration”, and that he “can only presume” that Dr. Lawson failed to consider it. He testified further that a reasonable and prudent gynecologist who had included ureteric injury in his or her differential diagnosis “probably would have” pursued further investigation. This led to the following exchange:

Q. That would have been the standard of care, you would have expected at the time

A: If that was – index of suspicion was high for uretic injury, that would be [the] next steps, yes.

[182] Dr. Hunter ultimately agreed that Dr. Lawson “should have considered” the possibility of a ureteric injury, and that although he had not heard her trial testimony, “[i]t wasn’t considered in the notes”. This led to the following exchange with the plaintiff’s counsel:

Q. And, you’d agree with me that her not considering it, it does fall below the standard of care.

A. One could argue that, yes. It’s not – I don’t think that’s a definitive below standard of care in the fact that she was still treating the patient and still considering other options and follow up if things did not improve.

[183] As I understood Dr. Hunter’s evidence, his opinion was that although the standard of care required a reasonable and prudent gynecologist in Dr. Lawson’s position to consider the possibility of a ureteric injury, it would still have been a reasonably acceptable choice for her to decide to hold off on consulting with a urologist to wait and see how Ms. Knight responded to the antibiotics. He noted that “it takes time for an observable change in hydronephrosis or an abscess”, and testified that in his view Dr. Lawson’s plan to have a follow up CT scan conducted in a week was reasonable. Dr. Hunter explained further that in his opinion it was:

… not inappropriate to follow the patient closely and … make sure that the condition that you’re believing it is at that particular time improves and if not further imaging should be done to rule out something like a uretic injury.

(3) Dr. Casey

(a) The admissibility of Dr. Casey’s standard of care evidence

[184] A preliminary issue that arose during the trial, and which I will now address, is whether opinion evidence about the standard of care to which reasonable gynecologists should be held can only come from other gynecologists – in this case, Dr. Browning and Dr. Hunter – or whether Dr. Casey, a urologist, can also give opinion evidence on this issue. The defence objected to Dr. Casey giving any such evidence, but agreed that since I was trying this case without a jury, I could hear his testimony and rule on its admissibility in my final judgment.

[185] As I have noted, in medical malpractice cases where the defendant doctor is a medical specialist, the question of negligence hinges on whether he or she “exercise[d] the degree of skill of an average specialist in his [or her] field”: Ter Neuzen, at para. 33. Unsurprisingly, opinion evidence about the applicable standard of care for a medical specialist is ordinarily given by other doctors who have expertise in the same area of specialization.

[186] However, there is no absolute rule that opinions about the standard of care in a particular case can only be offered by physicians who have the same level of specialist training as the defendant doctor. Rather, in Robinson v. The Sisters of St. Joseph, 1999 CanLII 2199 at para. 1 (Ont. C.A.), the Ontario Court of Appeal explained:

There is no general rule that a specialist cannot offer an opinion as to the applicable standard of care governing medical treatment provided by a general practitioner, or that the specialist cannot offer an opinion as to whether the general practitioner met the applicable standard. The admissibility of the specialist’s opinion depends on the subject matter on which that opinion is offered and the specialist's training and experience. Surely, there are treatments and procedures which are common to the practices of general practitioners and specialists alike.

[187] Although Robinson and Barber deal with the issue of when a specialist can opine about the standard of care that should apply to generalists, medical specialists with different areas of speciality and generalist physicians all share the same baseline medical training. In Barber, Cronk J.A. agreed with the proposition that while the standard of care expected of a specialist can be higher than “the minimum standard expected of all MDs”, it can never be lower.

[188] In my view, it follows that in appropriate circumstances a specialist in one area can properly opine about the minimum standard of care that should be observed by all physicians, whether they are specialists or generalists.

[189] In this case, the plaintiff seeks to have Dr. Casey give his opinion about when doctors who are not specialists in urinary system disorders – whether they are generalists, or specialists in some other area, such as gynecology – ought to seek the advice of a urologist. In my view, Dr. Casey’s ability to give this evidence falls within the scope of Robinson and Barber. It does not require Dr. Casey to express any opinions about the adequacy of the gynecological care and treatment that Ms. Knight received, which would plainly fall outside his area of expertise.

[190] I recognize that it would be inappropriate for Dr. Casey to hold Dr. Lawson to the higher standard of care that may apply within his own area of speciality, urology, and that there is a real concern that he might unconsciously do so. However, I am satisfied that I can address this concern when deciding the weight I give to his standard of care evidence, and that it does not make his evidence inadmissible.

[191] I would add that while there is no dispute over Dr. Browning and Dr. Hunter’s qualifications to express opinions about the standard of care expected of a fellow gynecologist, their limited first-hand experience dealing with patients with ureteric injuries constrains their practical ability to assess how a reasonable and prudent gynecologist ought to handle such cases. Dr. Casey’s own personal experience with surgical ureteric injury cases is also limited, but is more extensive than that of either Dr. Browning or Dr. Hunter. In these circumstances I find it helpful to also take into account Dr. Casey’s views about when reasonable surgeons who are not urologists should seek urological advice, while keeping in mind that his opinion may be unduly influenced by his own expertise as a urologist.

(b) Dr. Casey’s opinion

[192] In Dr. Casey’s view, the clear indication of potential ureteric and kidney problems on the February 18, 2014 CT scan made it incumbent on any physician who was responsible for Ms. Knight’s care to at least discuss her case with a urologist. He testified:

[I]f a patient such as this presented to the emergency room with right flank pain and evidence of an obstructed ureter, they would be referred to urology immediately. I can see that because this was a post-op surgical patient that the gynaecologist would then become the most responsible physician, but in my opinion, this – these findings are mandatory that a urologist get involved and should have been, should have been at least – the case should have been discussed with the urologist at that time, in my opinion.

[193] Dr. Casey also emphasized the importance of follow-up imaging “to determine whether … the issue is resolving or getting worse, particularly if you’ve demonstrated an obstructed right kidney and abscess”. He was somewhat critical of Dr. Lawson’s decision to discharge Ms. Knight on February 23, 2014, five days after her readmittance to hospital, without further imaging showing that her kidney and ureteric issues were improving along with her other symptoms.

c) Findings and conclusions on standard of care

[194] On all the evidence, I find that Dr. Lawson fell short of the applicable standard of care when she failed to consult with a urologist after learning on February 19, 2014 that Ms. Knight had a severely swollen right kidney and distended right ureter, six days after her surgery on February 13.

[195] The expert witnesses, including Dr. Hunter, all agreed that a reasonable and prudent gynecologist in Dr. Lawson’s position should have been concerned about the possibility of Ms. Knight’s ureter having been injured during the surgery, even if this seemed less likely than the alternative possibility that her kidney and ureteric issues were caused by an infection, either in the form of the apparent abscess or in her right kidney. It is of some significance that the problems with Ms. Knight’s ureteric system were on the right side of her body, which is the same side that Dr. Lawson had performed the salpingo-oophorectomy.

[196] Since problems with a patient’s kidney and ureter are plainly issues that fall within a urologist’s area of expertise, I think it is more likely than not that if Dr. Lawson had properly turned her mind to the possibility of a ureteric injury, she would have arranged a urological consultation, even if I accept Dr. Hunter’s evidence that some reasonable gynecologists in her position might have made a considered decision to watch and wait before taking this step.

[197] I am mindful that physicians cannot be held to a standard of perfection, and that not all mistakes in judgment, or decisions that turn out to be mistakes with the benefit of hindsight, can properly be viewed as negligent. However, the defence’s own gynecological expert, Dr. Hunter, agreed in cross-examination that when a gynecologist has recently performed surgery that involved using a cautery device in close proximity to the patient’s ureters, the possibility of the patient having a thermal ureteric injury must be considered, and that “[a] high index of suspicion must be carried through the post-operative period”. Dr. Lawson, who had used a cautery device when she performed Ms. Knight’s surgery six days earlier, acknowledged that she did not consider this possibility when Ms. Knight returned to her care on February 19, and that this was why she did not include it in the differential diagnosis that she recorded in her notes.

[198] Dr. Lawson offered three main explanations for why she did not turn her mind to this possibility.

[199] First, she testified that Dr. Moreau had told her during their earlier phone call, before Ms. Knight arrived back at Stevenson Memorial, that she was being transferred back to Dr. Lawson’s care with an abscess, but that Dr. Moreau did not say anything about the possibility that Ms. Knight might have a ureteric injury.

[200] Dr. Lawson testified that if Dr. Moreau had mentioned this possibility, she would have declined to accept the transfer of Ms. Knight from RVH, since Stevenson Memorial, unlike RVH, did not offer any urological services. Dr. Lawson later explained that she also did not think that Dr. Moreau would have proposed the transfer if he had suspected a ureteric injury himself.

[201] Second, Dr. Lawson explained that when she arrived at her differential diagnosis, she had relied on Dr. Tynan’s CT scan report, which had specifically “indicated abscess or pyelonephritis”, but not mentioned the possibility of a ureteric injury.

[202] Third, Dr. Lawson explained that another reason she did not suspect a ureteric injury was because she had checked Ms. Knight’s ureters at the end of the February 13 surgery and had not seen any problems. As she put it in cross-examination,

I did not consider ureteric injury because we had seen the ureters. And, so that was why that was not on the differential.

[203] Although I accept Dr. Lawson’s evidence about the reasons why she did not turn her mind to the possibility that Ms. Knight might have a surgical ureteric injury, I do not think her reasons provide a justification for her failure to consider this possibility.

[204] As I have already discussed, I accept that Dr. Lawson probably did check Ms. Knight’s ureters at the conclusion of the February 13, 2014 surgery, and did not see anything amiss with them. However, on Dr. Hunter’s evidence, which I also accept, a thermal injury to the ureteric blood vessels would probably not have been visually observable at the time.

[205] In my view, a reasonable gynecologist in Dr. Lawson’s position ought to have known that a negative visual check of the patient’s ureters at the time of surgery was far from definitive, and did not substantially reduce the possibility that Ms. Knight could now be displaying post-surgical signs of a ureteric injury.

[206] It is certainly understandable why Dr. Lawson’s thinking was influenced by Dr. Moreau’s suggestion during their telephone conversation that Ms. Knight had an abscess, particularly after she saw Dr. Tynan’s CT scan report that suggested this same diagnosis. Indeed, Ms. Knight probably did have an abscess. However, it was incumbent on Dr. Lawson to keep an open mind, consider other possibilities, and guard against the risk of confirmation bias. She could not simply accept Dr. Moreau and Dr. Tynan’s suggestions, but had to use her own skill and judgment to form her own independent conclusions. She had no reason to think that Dr. Moreau had superior information about Ms. Knight, or that he was otherwise in a better position to assess Ms. Knight’s condition.

[207] While Dr. Tynan did have some superior information – she had seen the CT scans themselves, whereas Dr. Lawson only saw Dr. Tynan’s report describing what she had seen on the scans – Dr. Lawson also knew things about her long-time patient, Ms. Knight, that Dr. Tynan might very well not have known.

[208] Perhaps most importantly, Dr. Lawson knew that she had recently performed LAVH surgery on Ms. Knight, and that during the surgery she had made extensive use of a cautery device. Ureteric injuries are known to be a serious, although infrequent, complication of this type of surgery, and the use of a cautery device during this surgery creates a particular risk that the patient might suffer a thermal ischemic ureteric injury, which will probably not be detectable intraoperatively, and will only reveal itself days or weeks later.

[209] Dr. Lawson had no particular reason to assume that Dr. Moreau or Dr. Tynan necessarily knew these important details of Ms. Knight’s recent medical history. In my view, this made it all the more important for Dr. Lawson to make her own independent assessment of the situation and draw her own conclusions, rather than simply accepting what she thought the RVH doctors were suggesting.

[210] The defence argues that because numerous other doctors, including two other gynecologists, were involved in Ms. Knight’s treatment at RVH, and later at Stevenson Memorial, and because none of these other physicians ever thought to bring in a urologist, I should find that Dr. Lawson did not fall below the standard of care when she did not do so herself.

[211] I do not accept this argument, for four main reasons.

[212] First, until the CT scan was conducted and interpreted, there seems to have been no concrete reason to believe that Ms. Knight had any problem with her urinary system. Although the scan seems to have been performed on February 18, 2014, the day that Ms. Knight was first admitted to RVH, Dr. Tynan’s report interpreting the scan is dated the next day, February 19.

[213] Dr. Tynan’s report does not indicate what time it was prepared that day, but other RVH documentation indicates that an emergency room physician reviewed her report and discussed it with Dr. Moreau at 7:20 a.m. that morning. Other RVH documents show that Ms. Knight was then sent to Stevenson by ambulance less than four hours later, shortly before 11:00 a.m.

[214] I cannot speculate about how many RVH physicians might have reviewed Dr. Tynan’s report before Ms. Knight was transferred back to Stevenson Memorial. However, it is clear that at least some of the doctors who had contact with Ms. Knight during her stay at RVH from February 18-19 could not have reviewed the report, because Dr. Tynan did not write it until some time in the early morning of February 19.

[215] Second, while the defence is correct that Dr. Moreau “would have had access to Ms. Knight’s CT scan” and other documentation, this is true only in the limited sense that he could have reviewed these materials. There is no evidence that he actually did review them, although one document shows that Dr. Moreau did at least discuss the CT scan with an emergency room physician before he directed that Ms. Knight be transferred back to Dr. Lawson’s care at Stevenson.

[216] Dr. Browning, who spent most of his career practicing at RVH and was formerly its chief of gynecology, interpreted the RVH documents as indicating that Dr. Moreau was only consulted by the emergency room staff informally, which in his view made it unlikely that Dr. Moreau would have read all of the available documents. Dr. Browning testified:

Dr. Moreau, I don’t believe performed a consultation, so I doubt very much that he would have reviewed that information per se. He might have been told it by the ER doctor, but I doubt very much that … he reviewed it if he didn’t do a consultation on the patient.

[217] Dr. Browning’s understanding of the limited role that Dr. Moreau probably played in Ms. Knight’s care at RVH strikes me as a plausible reading of the documentary record. I think it would be speculative for me to conclude that Dr. Moreau was necessarily as fully-informed about Ms. Knight’s condition as the defence suggests. I am not prepared to reject Dr. Browning’s evidence on this point on the basis that he and Dr. Moreau are long-time professional colleagues and business partners.

[218] Third, even if I were to assume that Dr. Moreau was aware that the CT scan showed that Ms. Knight had a severely swollen right kidney and a distended right ureter, and that he also knew about her recent surgery, I am not prepared to treat Dr. Moreau as a proxy for a hypothetical reasonable and prudent gynecologist.

[219] Essentially, the defence’s argument is that because Dr. Moreau did not refer Ms. Knight to a urologist at RVH, and instead arranged her transfer to a hospital that had no urologists on staff, it can be concluded that a reasonable and prudent gynecologist with the same information as Dr. Moreau and Dr. Lawson would not have thought that a urological consultation was necessary.

[220] Even if I accept Dr. Browning’s acknowledgement that Dr. Moreau is a reasonable and competent gynecologist, I am not prepared to treat Dr. Moreau’s actions and inactions as setting the bar for the applicable standard of care.

[221] As I understood Dr. Hunter’s evidence, his opinion was that a reasonable and prudent gynecologist who was fully informed of the relevant facts should have turned his or her mind to the possibility that Ms. Knight’s ureter had been damaged during her recent surgery but that, having done so, it might still have been reasonable for the gynecologist to delay consulting with a urologist to see how Ms. Knight responded to antibiotics. I cannot properly conclude on the sparse documentary record available to me that Dr. Moreau ever made such a considered decision, without either discussing it with Dr. Lawson or creating any written record of his thought process in RVH’s files.

[222] Fourth, I attach no significance to the evidence that during Ms. Knight’s hospitalization at Stevenson Memorial from February 19 to 23, 2014, she was seen on one day – February 22 – by another gynecologist, Dr. Kilani, who was filling in for Dr. Lawson. By this date Ms. Knight’s condition seemed to be improving, and she was discharged the next day.

[223] In my view, it not realistic to expect a locum in Dr. Kilani’s position to second-guess Dr. Lawson’s treatment decisions when making her rounds and to arrange a urological consultation, particularly when the patient seemed to be responding well to the antibiotics prescribed by Dr. Lawson, and reported feeling better. Moreover, Dr. Kilani might well have reasonably assumed that Dr. Lawson had already discussed her treatment plan with a urologist.

[224] In summary, I find that Dr. Lawson fell below the applicable standard of care on February 19, 2014 when she failed to turn her mind to the possibility that Ms. Knight had suffered a ureteric injury during the surgery that Dr. Lawson herself had performed six days earlier.

[225] On February 19 Ms. Knight obviously had a problem with her right kidney and ureter. It was certainly possible that these problems were caused by an infection, and there were reasons to think this was the most likely explanation. However, it was also possible, even if perhaps less likely, that something different and more serious was going on. Accidental damage to the ureters is one of the known risks of the surgical procedure that Dr. Lawson had performed on Ms. Knight a few days earlier, and when the surgery is performed using a thermal cautery device, as Dr. Lawson did, it is foreseeable that the blood supply to the ureter may be compromised in a way that will not be observable to the operating surgeon.

[226] All three expert witnesses who addressed the standard of care issue agreed that a gynecologist in Dr. Lawson’s position should, at a minimum, have given the possibility of Ms. Knight having a ureteric injury serious consideration. Dr. Hunter, who of the three experts was the least critical of Dr. Lawson, agreed that a gynecologist in her position should have approached the possibility of a ureteric injury with a “high index of suspicion”. Dr. Lawson, on her own evidence, did not do this.

[227] The defence relies on my colleague Woodley J.’s comments in Owala v. Makary, 2021 ONSC 7476, at para 88, where she noted that a physician cannot be faulted for failing to “anticipate the worst case but most unlikely scenario”. Woodley J. took this proposition from Gilmore J., judgment in Lee (Litigation guardian of) v. Southlake Regional Health Centre, 2015 ONSC 7509, at para. 143, where the plaintiff’s experts had described the risk of the patient suffering the complication at issue as “either one in a billion or as close to zero as possible”.

[228] The situation in the case at bar is very different. While the chances of Ms. Knight having suffered a surgical ureteric injury may not have been high, this possibility was not vanishingly small. Rather, it was a possibility that the three standard of care expert witnesses unanimously agreed had to be given serious consideration.

[229] All that said, I agree with the defence that Dr. Lawson’s liability in tort is not determined by what she was thinking, but by what she did and did not do. A defendant’s negligent thought process is not tortious if it does not translate into negligent actions or inaction. As Mr. McLeod and Mr. Lewis put it in their factum:

[A] failure to consider a possible issue, or to include a possible issue in one’s differential diagnosis, cannot ground a finding of liability in the circumstances of this case; only a negligent act or omission by Dr. Lawson can.

[230] In this regard, the standard of care expert witnesses parted company over the question of whether a reasonable gynecologist in Dr. Lawson’s position, who unlike her did properly consider the possibility of a ureteric injury, would necessarily have taken the next step of seeking advice from a urologist.

[231] Dr. Browning and Dr. Casey answered this question in the affirmative. Dr. Casey, who I acknowledge sees this issue from a urologist’s perspective, considers it incumbent on any physician confronted with evidence of a blocked ureter to seek advice from a urologist.

[232] Dr. Browning also thought that in this situation a reasonable and prudent gynecologist would have referred Ms. Knight to a urologist to come up with “a game plan for the dilated ureter”. However, his opinion on this point is influenced by his view that a ureteric injury was the mostly likely cause of Ms. Knight’s right hydronephrosis and distended right ureter. I am not prepared to go that far. While I have found that the possibility of a ureteric injury was one that had to be given serious consideration, I accept Dr. Hunter’s evidence that there were a number of reasons to believe that the alternative infection scenarios were collectively more likely.

[233] Dr. Hunter’s opinion was that a reasonable and prudent gynecologist who concluded that an infection was more likely than a ureteric injury could reasonably decide to hold off consulting a urologist until he or she saw how Ms. Knight responded to antibiotics.

[234] I find it unnecessary to resolve this dispute between the expert witnesses, because in the circumstances here I do not think that Dr. Lawson, who did not turn her mind to the possibility of Ms. Knight having a ureteric injury, can take shelter behind the possibility that a reasonable and prudent physician who had properly considered this possibility might still have made a reasoned decision not to consult with a urologist immediately.

[235] Even if I were to accept Dr. Hunter’s opinion that the question of when to consult with a urologist was a discretionary judgment call, over which reasonable gynecologists who properly considered the issue could disagree, Dr. Lawson did not make a considered decision to delay seeking urological advice. Rather, on her own evidence, she never turned her mind to the advisability of consulting with a urologist, because she simply assumed that the issues with Ms. Knight’s right kidney and ureter were caused by the probable infections and were not symptoms of an underlying ureteric injury.

[236] I think if Dr. Lawson had properly considered the issue, it is more likely than not that she would have erred on the side of caution and arranged to speak with a urologist. There would have been no compelling reason for her not to do so. Even though Stevenson Memorial did not have any urologists on staff, it is undisputed that Dr. Lawson could have very easily arranged to consult with a urologist at another hospital by telephone. As Dr. Casey put it, “if there were phones in the area, [urologists] were available”.

[237] Even if some reasonable and prudent gynecologists who considered the possibility of a ureteric injury might have identified some case-specific reason not to seek advice from a urologist right away, Dr. Lawson did not articulate any such reason in Ms. Knight’s case.

[238] I am also satisfied that if Dr. Lawson had spoken to a urologist on February 19, 2014, the urologist would probably have recommended stenting Ms. Knight’s right ureter, which the CT scan plainly showed was obstructed. Dr. Casey testified that:

[I]t would be my opinion that most urologists would agree that early stenting is an important part of the management of an injury like this.

[239] Dr. Casey also noted that he had reviewed the report prepared by another defence urologist, Dr. Sid Radomski, who did not testify at trial, and observed:

Dr. Radomski’s report suggested that early intervention wouldn't have made … a big difference but in the same breath mentioned that he would have, had he been asked to stent the patient, or see the patient earlier, he would have stented the patient immediately.

Dr. Casey added:

I think you'd be hard pressed to find a urologist based who, based with the facts of the presentation on day six with an obstructed kidney and febrile patient post-abdominal pelvic surgery would not have stented that patient to treat the infection.

[240] Although Dr. Buckley does not think in hindsight that earlier stenting would have done Ms. Knight any good, he also agreed that if Ms. Knight had been his patient he would still have tried to stent her at the earliest opportunity, testifying:

I personally do stent them if … given the opportunity. Nothing against stenting; I think it’s a logical first step if a patient presents with a scenario that you could get a stent up.

[241] On all the evidence, I am satisfied that if Dr. Lawson had consulted with a urologist on February 19, 2014, the most likely result would have been that Ms. Knight would have been transferred to a hospital with urological services, so that an attempt could be made to place a stent in her right ureter. I also find that this would likely have happened relatively quickly, within no more than one or two days.

[242] There is no guarantee that a urologist would have been able to successfully install a stent at this time, as Dr. Kim was ultimately able to do with some difficulty two weeks later on March 5, 2014. However, Dr. Casey and Dr. Buckley both agreed that if a urologist had been unable to stent Ms. Knight’s right ureter, he or she would probably have installed a nephrostomy tube to drain urine from her right kidney and relieve her hydronephrosis. Dr. Casey explained that this would have been a second-best option as compared with stenting, “because while it drains urine away from the … site it doesn’t drain all the urine away, and it doesn’t keep the ureter open when it heals”.

[243] For the purpose of my analysis, I am prepared to assume that there was at least a slightly better than 50% chance that Ms. Knight could have been successfully stented within a few days of February 19, 2014. The critical question, to which I will now turn, is whether earlier stenting would likely have appreciably changed the course of Ms. Knight’s medical condition and outcome.

2. Causation: Did Dr. Lawson’s failure to consult with a urologist affect the course of Ms. Knight’s recovery?

[244] Ms. Knight’s burden on her second theory of liability is to establish not only that Dr. Lawson was negligent in not taking steps that would have resulted in her being stented sooner, some two weeks before she was actually stented by Dr. Kim, but also that earlier stenting would probably have substantially improved her prognosis and outcome.

[245] Although the burden of proving causation is born by Ms. Knight, as the plaintiff, the Supreme Court of Canada has endorsed taking a “robust and practical approach” to issues of causation in medical malpractice cases: Snell v. Farrell, 1990 CanLII 70 (SCC), [1990] 2 S.C.R. 311 at p. 330. As Sopinka J. explained for the Court, at p. 330: “

The legal or ultimate burden remains with the plaintiff, but in the absence of evidence to the contrary adduced by the defendant an inference of causation may be drawn although positive or scientific proof of causation has not been adduced. If some evidence to the contrary is adduced by the defendant, the trial judge should weigh that evidence according to the proof.

[246] However, as the Ontario Court of Appeal observed in Salter v. Hirst, 2011 ONCA 609 at para. 14:

There is no issue that “loss of a chance” is not compensable in medical malpractice cases. The plaintiff must prove on the balance of probabilities that, but for the doctor's negligence, the unfavourable outcome would have been avoided with prompt diagnosis and treatment: Cottrelle v. Gerrard (2003), 2003 CanLII 50091 (Ont. C.A.), 67 O.R. (3d) 737, [2003] O.J. No. 4194 (C.A.), at paras. 25, 36.

[247] In summary, Ms. Knight bears the onus of proving that it is more likely than not that she would have been materially better off if she had been stented two weeks earlier than she actually was, either because she would have avoided the need for further repair and reimplantation surgery entirely, or because earlier stenting would have substantially alleviated her symptoms and discomfort while she waited for this surgery to take place.

a) The evidence

[248] In this case, both sides have presented expert opinion evidence on the issue of causation.

[249] Ms. Knight relies primarily on Dr. Casey’s evidence. However, Dr. Browning, who is not a urologist, also suggested that earlier stenting might have prevented Ms. Knight’s ureter from rupturing by relieving the pressure of the backed-up urine. He testified:

I mean if the ureter was stented early, you know, it’s certainly more likely than not that there wouldn’t have been as much pressure on the area of concern, and it’s possible that … that area may not have ever leaked, it may have healed… on its own with time if it didn’t have the added pressure on a lumen … that you get if you’ve got high pressure in the lumen of the tube. That pressure is relieved if the ureter is stented.

[250] During his evidence in chief, Dr. Casey also suggested that early stenting could have prevented the rupture by relieving the pressure buildup, testifying:

It’s hard to be certain, but it, it would be hoped that by stent, stenting the ureter … before the ureter ruptured, that none of this would be present and, and it’s my opinion that early on when the right kidney was obstructed and swollen, that if stenting had been done then, there’s a much more likely that you wouldn’t have seen the pressure build up and the blow out of the ureter and the hole. We can’t be certain and it’s possible that none of this would have been present.

[251] However, Dr. Buckley explained in detail why he believes the premise that the hole in Ms. Knight’s ureter was caused by the pressure of backed-up urine to be incorrect. He made what I consider to be two important points in support of his opinion.

[252] First, Dr. Buckley gave detailed evidence about the underlying mechanism of a surgical thermal ischemic ureteric injury. As I have already discussed, this is the type of injury that he, Dr. Casey and Dr. Hunter all believe Ms. Knight suffered, and I have already explained why I accept their opinion on this point.

[253] In the thermal ischemic injury scenario, the blood vessels that supply and sustain the wall of the ureter are damaged by the heat from a surgical cautery device. The resulting ischemia – that is, lack of adequate blood supply – eventually causes the ureteric tissue to die and break down (“ischemic necrosis”), which leads to a hole, or multiple holes, forming in the ureteric wall. Urine then leaks out through these holes into the patient’s abdomen. Dr. Buckley explained:

The pathophysiology is that the cautery causes ischemia to the ureter. There is subsequent swelling which causes obstruction. The ureteric tissue then breaks down in that 1-2 week postoperative period. The urine then leaks into the abdomen and eventually through the vaginal cuff, creating a ureteral vaginal fistula.

[254] Dr. Buckley testified further that once holes have formed in the ureteric wall because of ischemic necrosis they rarely heal on their own, unless they are very small. He explained:

[I]f it’s an ischemic injury … what’s going to happen, a stent isn’t going to influence that whatsoever. If it heals, it heals, that’s great, but more often than not it doesn’t heal, it either scars down .., or it opens up and it – that depends on how … how [bad] the … devascularization injury is.

In contrast, he explained that laceration injuries usually will heal after ureteric stenting “because you’ve got two vascularized edges that you’ve sewn together, so they, they should heal normally.”

[255] Importantly, in my view Dr. Casey agreed that the likelihood of an ischemic necrosis injury healing without surgical correction “depends on the degree of ischemia that was produced on the injury”. In other words, he agreed that small holes may heal on their own, but that larger ones are unlikely to do so.

[256] Second, Dr. Buckley provided a helpful and unchallenged explanation of how ureteric stents work. Unlike coronary stents, ureteric stents do not expand and press up against the wall of the ureter. Rather, they have a fixed diameter, and the ureter tends to dilate once a stent has been installed, leaving additional space between the stent and the ureteric wall. Ureteric stents are also permeated with holes. Once a ureteric stent is in place, some urine will flow through the stent from the kidney to the bladder, but more urine will flow in the space between the outside of the stent and the ureteric wall. Accordingly, installing a ureteric stent will not stop urine from leaking into the abdomen through any holes that are in the ureteric wall.

[257] In a passage from one of his reports that he adopted at trial, Dr. Buckley explained why, in his opinion, earlier stenting would probably not have had any impact on Ms. Knight’s progression or the speed of her recovery:

It is my opinion that had Ms. Knight been stented earlier in the course of her recovery this more likely than not would not have prevented the subsequent development of her ureterovaginal fistula. Specifically if she had been stented during her February 19-23, 2014 admission, I think she still would have presented on March 3, 2014 with a urine leak. This is the nature of an ischemic injury to the ureter. The ureter will break down and leak despite the presence of the stent. It is actually quite unusual for injuries such as this to heal on their own. Definitive treatment of a ureterovaginal fistula with a ureteric reimplantation is usually needed. This can be performed in the first couple of days following abdominal or pelvic surgery if it is recognized but once this time period has occurred it is wiser to wait until the pelvic field has settled down and healed. This typically would be a minimum of two months following the original surgery. In summary, Ms. Knight very likely would have required the same definitive treatment that she received in the postoperative period.

[258] Importantly, Dr. Casey ultimately did not dispute Dr. Buckley’s opinion that it was more likely than not that earlier stenting would not have made a difference in Ms. Knight’s case. In the course of preparing his report Dr. Casey had reviewed several journal articles in which the authors had concluded that earlier stenting of patients with ureteric injuries increased the chances of the patients not needing reimplantation surgery. In his report, he had stated:

While published results vary somewhat, all recent publications agree that early intervention (within 2 weeks of the surgical injury) will likely avoid subsequent renal loss and the need for an open repair. Approximately 20 percent of ureteral injuries will resolve without the need for further procedures when there is early endoscopic intervention.

In cross-examination, he explained that he had arrived at the 20 percent estimate:

… based on looking at three or four of the references and it ranges from, you know, 12 percent to 30 - and it really depends on the nature, like I mentioned earlier, the nature of injury, the mechanism of action.

Dr. Casey also agreed that the literature he had reviewed did not provide “specifics about what type of injuries are discussed in these articles”.

b) Findings

[259] While I agree that the literature Dr. Casey reviewed and referenced tends to suggest that earlier stenting can benefit some patients, it does not logically follow that early stenting will benefit all patients equally or, even more importantly, that earlier stenting would have benefitted Ms. Knight, given the specific nature of her ureteric injury.

[260] As Dr. Buckley explained, there are well-understood physiological reasons why laceration-type ureteric injuries heal better with stenting than ischemic injuries. The studies Dr. Casey relied on do not distinguish between any of the different injury mechanisms.

[261] Moreover, the statistical evidence Dr. Casey cited does not support the conclusion that stenting Ms. Knight approximately two weeks earlier would have made it more likely than not that she would have avoided surgery.

[262] Even if I accept Dr. Casey’s conclusion that “approximately 20 percent of ureteral injuries will resolve” without surgery when the patient is stented within the first two weeks following the injury, some percentage of these injuries would also have resolved without surgery even if the patient had been stented later. Equally significantly, the implication of Dr. Casey’s 20% figure is that approximately 80 percent of ureteral injuries will not resolve on their own, even with early stenting.

[263] Dr. Casey relied in particular on one published paper that conducted a “meta-analysis” of other published papers, from which the authors concluded that patients who were stented in less than two weeks of their ureterovaginal fistulas being detected had a 95% “pooled success rate”, whereas patients stented between two and six weeks of fistula detection had a pooled success rate of 63%, while patients who were stented after six weeks had a pooled success rate of only 20%. However, the authors also noted that the papers they had reviewed did not always agree on the definition of “success”, and that some had not defined it at all.

[264] Even I were to assume that “success” can be taken to mean “avoiding surgery”, I do not think it can be concluded that Ms. Knight’s chances of avoiding surgery would have been appreciably higher if she had been stented approximately two weeks earlier than she actually was.

[265] Dr. Casey and Dr. Buckley both agreed that an extremely significant factor that affects the likelihood of patients avoiding surgery, regardless of when they are stented, is “the nature of injury [and] the mechanism of action”. As Dr. Buckley explained, laceration-type ureteral injuries are much more likely to heal without surgery than ischemic injuries, for well-understood physiological reasons. The reported high “success rate” of patients who are stented very early is very likely skewed by the fact that laceration-type injuries are both the most likely to heal with stenting, and also the most likely to be detected intraoperatively because they are often observable visually: see para. 42, supra.

[266] In this case, Ms. Knight was stented on March 5, 2014, 20 days after her right ureter was injured. Her injury did not heal on its own after stenting, and she ultimately needed to have surgical reimplantation surgery. Even if I were to accept that around 20 percent of patients with all forms of ureteric injury will heal without surgery when they receive early stenting, it does not follow that earlier stenting of Ms. Knight’s ureter would have put her in this 20 percent group, rather than leaving her in the larger 80 percent group who still required surgery. Dr. Buckley’s opinion was that the nature of Ms. Knight’s specific injury made it very unlikely to heal spontaneously, no matter when she was stented. Nothing in the literature that Dr. Casey reviewed and relied on stands against Dr. Buckley’s opinion on this point.

[267] I accept Dr. Buckley’s evidence. While I found him and Dr. Casey to both be impressive witnesses, Dr. Buckley has considerably more extensive experience dealing with ureteric injuries. His opinion that Ms. Knight would more likely than not have needed reimplantation surgery even if she had been stented earlier was based not just on his empirical experiences treating these types of injuries, but also on his understanding about how ischemia affects the ability of tissue to heal.

[268] Moreover, as I understood Dr. Casey’s evidence, he did not disagree with Dr. Buckley about either of these points. Ultimately, his opinion was that early stenting was advisable even if it only improved the patient’s chance of avoiding surgery by a small amount, if at all. As he explained in his testimony:

[T]he literature that … we looked at, suggested that early intervention before there's chance for cross-healing and everything resulted in correction in a certain percentage - 10 percent, 20 percent, which is what, if I was a patient, I, I'd want a 10 percent chance of not needing more surgery, if I had an option.

[269] I do not think the literature to which Dr. Casey was referring to supports the conclusion that an individual patient’s chances of avoiding surgery will improve by 10 percent if stenting is done earlier rather than later. However, I agree with his broad point that since patients who can avoid surgery will be better off than patients who require surgical reimplantation of their ureters, anything that can be done to reduce the odds of a patient requiring surgery even slightly is worth doing. Indeed, Dr. Buckley agreed with this, testifying that if it had been up to him, he would have stented Ms. Knight as soon as possible.

[270] However, I do not agree with the plaintiff that this undermines Dr. Buckley’s opinion that early stenting would probably not have significantly changed Ms. Knight’s situation. His opinion was based on his belief that she had probably suffered a thermal ureteric injury that was unlikely to heal without surgery. Since there is at least some chance that her injury was of a different nature, making it one that might be more likely to heal on its own after stenting, and since some thermal ischemic injuries also heal without surgery, I think it makes perfect sense for Dr. Buckley to acknowledge that he would still have stented Ms. Knight if she had been his patient, even though he would not have thought that it was likely to result in her avoiding surgery. Moreover, even when patients with ureterovaginal fistulas ultimately require repair and reimplantation surgery, stenting may relieve their symptoms by reducing the amount of urine that flows into their abdomen, even though it will not stop the flow entirely.

[271] Ms. Knight’s burden in this case is to show that earlier stenting would more likely than not have led to an improved outcome for her. I am not satisfied that the evidence establishes this. To the contrary, I accept Dr. Buckley’s evidence that even if a stent had been placed in Ms. Knight’s right ureter on or about February 20, 2014, the progress of her presentation and treatment would have remained essentially the same. In all likelihood she still would have needed repair and reimplantation surgery, and Dr. Kim, or any other urologist who treated Ms. Knight in this alternative timeline, would still have delayed the surgery for several months to avoid the problems that would have likely arisen if the surgery had been attempted before her tissues had had time to heal.

[272] I should add that if repair and reimplantation surgery would have been required in any event, I find that it would be speculative, on the evidential record before me, to conclude that earlier stenting would have significantly ameliorated Ms. Knight’s condition during the time she was awaiting surgery. In particular, I am not satisfied on the evidence that earlier stenting would have prevented Ms. Knight from developing a ureterovaginal fistula. Dr. Buckley’s evidence, which I accept, is that a hole would still have formed in the wall of her right ureter once the tissue broke down because of ischemic necrosis, through which urine would still have flowed into her abdomen and eventually drained out of her vagina. While the flow of urine through her vagina may have been reduced by earlier stenting, I find that it is unlikely that it would have stopped altogether, since the flow did not entirely stop even after she was successfully stented.

3. Conclusions on Ms. Knight’s second theory of liability

[273] In summary, I agree with Ms. Knight that Dr. Lawson fell below the standard of care on February 19, 2014 when she did not consider the possibility that Ms. Knight might have a surgical ureteric injury. I also find that if Dr. Lawson had turned her mind to this possibility she probably would have referred Ms. Knight to a urologist, and that this would likely have led to Ms. Knight’s right ureter being stented approximately two weeks earlier than it actually was.

[274] However, I am not satisfied that earlier stenting would have made any real difference in this case. Rather, I find that the probable nature of Ms. Knight’s injury – an ischemic injury to her ureter that was probably caused by the cautery device Dr. Lawson had used during the LAVH surgery – made it one that was unlikely to heal on its own without surgical repair. Earlier stenting would not likely have led to Ms. Knight avoiding the need for further surgery, nor would it have accelerated the timeline when she could have had the surgery.

[275] It follows that I am not satisfied that Ms. Knight has established that Dr. Lawson’s negligence caused her any compensable injury.

IV. Damages

[276] In view of my conclusion that I am not satisfied that Ms. Knight has met her burden on either of her two alternative theories of liability, it follows that her action must be dismissed. This makes it strictly unnecessary for me to consider the issue of her damages.

[277] However, I will do so briefly out of an abundance of caution, in the event that I am wrong in my conclusions with respect to either of Ms. Knight’s alternative theories of liability.

[278] I should note that the parties have agreed on OHIP damages under both scenarios.

A. Damages under Ms. Knight’s first theory of liability

[279] If, contrary to my actual findings, Dr. Lawson was negligent in not identifying Ms. Knight’s ureteric injury intraoperatively, I find that the outcome of an intraoperative diagnosis would have been that Ms. Knight would probably have had repair and reimplantation surgery within a few days of February 13, 2019. A urologist would not have delayed surgery in the faint hope that the ureteric injury might heal on its own, since the undisputed evidence at trial is that there is only a narrow window during which the repair and reimplantation surgery can be performed after the initial operation, after which it must be delayed for several months.

[280] On this scenario Ms. Knight would still have experienced the pain and discomfort associated with the open repair surgery, and very likely would still have required a nephrostomy tube, a ureteric stent, and a Foley catheter for some time postoperatively, although she might have avoided needing an abdominal drain. Essentially, she would have avoided spending approximately 126 days, from February 14, 2014 to June 20, 2014, waiting for surgery in what I accept were extremely uncomfortable conditions. I do not accept that her current complaints of urinary frequency issues have been demonstrated to be causally related to her 2014 surgeries, and find that she has now made essentially a complete recovery.

[281] I agree with the defendant that on this scenario a reasonable figure for general damages would be on the order of $40,000, and that the cases relied on by the plaintiff where higher general damage awards were made are distinguishable on their facts.

[282] I will not review all of the cases relied on by both sides, but will address a few examples.

[283] In Bollman v. Soenen, 2012 ONSC 7090, where the trial judge awarded the plaintiff the equivalent of approximately $120,000 in inflation-adjusted damages, the premise of the trial judge’s finding of liability was that the defendant surgeon had operated on the plaintiff without her informed consent, and then made further negligent errors in her post-operative care after he accidentally but non-negligently transected her ureter during the surgery. In other words, the damages awarded in that case were premised on the assumption that but for the defendant’s tortious acts the plaintiff would have avoided surgery entirely because she would never have consented to it in the first place. Moreover, unlike Ms. Knight, the plaintiff in Bollman had suffered lasting injuries that the trial judge found left her “partially disabled”.

[284] Moreover, the defendant correctly points out that the trial decision in Bollman was reversed by the Ontario Court of Appeal on the issue of liability and a new trial ordered (2014 ONCA 36). At the new trial, the trial judge rejected the plaintiff’s claim that the operation had been performed without her informed consent, and awarded her $35,000 in general damages solely on the basis of delayed diagnosis (2016 ONSC 1424), although his finding on liability was also later reversed on appeal (2017 ONCA 391).

[285] In Knight v. Sloan, 2003 CarswellOnt 6374, the plaintiff was awarded the equivalent of $110,000 in today’s dollars. The plaintiff in that case, also named Ms. Knight, had spent approximately four months wearing a urine collection bag after her ureter was damaged during surgery. However, the defendant doctor in that case was found to have been negligent in damaging the plaintiff’s ureter by accidentally suturing it, and the plaintiff had to undergo eleven additional surgeries to address the complications, and had been left with lasting complications.

[286] In contrast, in the case at bar Dr. Lawson’s alleged failure to identify Ms. Knight’s ureteric injury intraoperatively did not result in Ms. Knight having to undergo any additional surgery. If her injury had been detected during the February 13, 2014 operation I find that she would still have had had to undergo the same repair and reimplantation surgery, although she would not have had to wait as long to have this surgery as she actually did. Moreover, I have found that she has made a full recovery.

[287] In summary, on this theory of liability I would fix the plaintiff’s general damages at $40,000. Since on this scenario she would have had the same surgeries that she actually had, but had the second surgery 126 days earlier, I agree with the defendants that the most she can claim for lost income is based on the assumption that she would have been able to return to work 126 days earlier than she did.

[288] I agree with the defendant that Ms. Knight has not made out her claim for loss of competitive advantage. I think it is speculative to conclude that she would have re-written the paralegal exam, which she had failed shortly before her surgery, if she had been able to return to work some four months earlier. In any event, she has now changed careers and is earning more money at her current employment than she was making in her previous line of work.

[289] In summary, I would assess Ms. Knights damages under her first theory of liability as follows:

i) General damages – $40,000;

ii) Loss of income – $4,938 (126 days of lost income);

iii) OHIP – $35,000 (agreed on between the parties).

TOTAL: $79,938

B. Damages under Ms. Knight’s second theory of liability

[290] On Ms. Knight’s alternative theory of liability, earlier stenting would have led to her injury healing without the need for repair and reimplantation surgery. Although my actual finding of fact is that this was unlikely, I will now attempt to play out the counterfactual scenario in which Ms. Knight’s injury did heal without surgery because of the earlier stenting, for the purposes of assessing Ms. Knight’s damages on this theory of liability.

[291] I do not agree with the defendant that on this scenario “Ms. Knight’s damages are limited to her clinical course between February 19, 2014 and March 5, 2014”. As I have already explained, I do not think the evidence supports the conclusion that earlier stenting would have prevented the development of Ms. Knight’s ureterovaginal fistula. In my view, the only basis on which Ms. Knight can claim damages under her second theory of liability is if it were concluded – contrary to my actual finding on the evidence – that earlier stenting would probably have made the June 20, 2014 repair and reimplantation surgery entirely unnecessary.

[292] For the purposes of this scenario, I will assume that Ms. Knight’s ureteric injury would have substantially healed by April 30, 2014. I base this on Dr. Kim’s decision to arrange surgery at this time, once he had satisfied himself that Ms. Knight’s injury had not yet healed, and his conclusion that at this point it was “doubtful and unlikely that [it] would heal on its own”. I take from this that Dr. Kim believed that if Ms. Knight’s injury was ever going to heal on its own, it would have done so by the end of April 2014.

[293] On this scenario, while Ms. Knight would still have probably developed a ureterovaginal fistula, she would have spent several fewer months than she did living with urine leaking out of her vagina, and presumably would have been able to have the stent, nephrostomy tube, abdominal drain, and Foley catheter removed by some time in May or June. She would then have been physically able to return work relatively soon thereafter, having avoided the June 20, 2014 open surgery and its associated recovery time.

[294] Moreover, since Ms. Knight’s evidence was that she delayed her actual return to work for some months even after she was physically able, because she was still suffering from the psychological effects of the terrible experience she had gone through over the past six months, I am prepared to assume for the purpose of my alternate timeline analysis that on this scenario Ms. Knight would have would have been able to go back to work by July 2014.

[295] However, I would still not give effect to Ms. Knight’s loss of competitive advantage claim. I am not satisfied that her decision to not re-take the paralegal examination was causally linked to her medical problems, or that qualifying as a paralegal would have put Ms. Knight on a significantly better career path than she is now on in her new field of work.

[296] On this analysis, I would assess Ms. Knight’s damages as:

i) General damages – $80,000;

ii) Loss of income – $8,344 (seven months of lost income);

iii) OHIP – $30,000 (agreed on between the parties).

TOTAL: $118,344

V. Disposition

[297] In the result, I am not satisfied that Ms. Knight has established liability under either of her two alternative theories. Her action is accordingly dismissed.

[298] I would urge counsel to try to agree on costs. If they are unable to do so, they may file brief written submissions of no longer than 5 pages in length, along with their bills of costs. The defendant’s submissions and bill of costs should be served and filed within 30 days of the date of release of this judgment, and the plaintiff’s responding submissions within a further 15 days. The defendant may then file brief reply submissions of no more than a single page within a further 15 days. All submissions may be served electronically and filed by email to my judicial assistant, or by posting them on Caselines.

The Honourable J. Dawe

Released: January 27, 2023

ONTARIO

SUPERIOR COURT OF JUSTICE

BETWEEN:

CHRISTINE KNIGHT

Plaintiff

– and –

DR. GLASINE LAWSON and STEVENSON MEMORIAL HOSPITAL

Defendants

REASONS FOR JUDGMENT

The Honourable J. Dawe

Released: January 27, 2023

[^1]: Ms. Knight also sued Stevenson Memorial Hospital, but the hospital was released from the litigation before trial.

I. Overview

II. The evidence

A. Dr. Lawson’s professional background and experience

B. The February 13, 2014 surgery performed on Ms. Knight by Dr. Lawson

C. The possible ways a patient’s ureter can be injured during pelvic surgery

D. Ms. Knight’s discharge from Stevenson Memorial (February 14, 2014)

E. Ms. Knight’s return to hospital on February 18, 2014

F. Ms. Knight’s transfer to Stevenson Memorial on February 19, 2014

G. Ms. Knight’s discharge from Stevenson Memorial Hospital on February 23, 2014

H. Ms. Knight returns to Stevenson Memorial (March 3, 2014)

I. Ms. Knight’s treatment at Southlake

III. Analysis

A. General Principles

B. Findings of fact regarding the cause of Ms. Knight’s ureteric injury

C. The plaintiff’s first theory of liability

1. Did Dr. Lawson fail to meet the duty of care by not detecting Ms. Knight’s ureteric injury intraoperatively?

2. Did any failure by Dr. Lawson to properly check Ms. Knight’s ureters cause Ms. Knight any harm?

3. Conclusions on Ms. Knight’s first theory of liability.

D. Ms. Knight’s second theory of liability

1. Did Dr. Lawson breach the standard of care by not considering the possibility of ureteric injury on February 19, 2014?

a) The evidence

b) The expert opinions

(1) Dr. Browning

(2) Dr. Hunter

(3) Dr. Casey

(a) The admissibility of Dr. Casey’s standard of care evidence

(b) Dr. Casey’s opinion

c) Findings and conclusions on standard of care

2. Causation: Did Dr. Lawson’s failure to consult with a urologist affect the course of Ms. Knight’s recovery?

a) The evidence

b) Findings

3. Conclusions on Ms. Knight’s second theory of liability

IV. Damages

A. Damages under Ms. Knight’s first theory of liability

B. Damages under Ms. Knight’s second theory of liability

V. Disposition

Judge

Counsel

Parties

Areas of Law

Fact Patterns

Expert Witnesses

Issues

Legal Tests 2