Clinical negligence update
Dr Jock Mackenzie explores a recent case involving a claimant practitioner's reliance on res ipsa loquitur
Claimant clinical negligence practitioners rarely rely upon the maxim res ipsa loquitur when advancing a case, but a recent judgment, Paula Thomas v Paul Curley  EWHC 2103 (QB), suggests that it still has its uses in the right circumstances.
The claimant claimed against a consultant general and vascular surgeon alleging primarily that he had caused an iatrogenic injury to her common bile duct (CBD) during a laparoscopic cholecystectomy on 10 October 2005. A secondary allegation related to the claimant's treatment between 19 and 21 October 2005 by failing to require fluid balance and renal monitoring of her condition.
The defendant appropriately performed a laparoscopic cholecystectomy for biliary colic due to a gallstone in the claimant's gallbladder. During the procedure, the defendant found a non-inflamed gallbladder and a single gallstone, and noted that the cystic duct came from the right hepatic duct rather than the CBD, a known but rare anatomical variation. As detailed in the operation note, the defendant isolated the cystic duct with clips and did likewise with the cystic artery, divided the structures and disconnected the gallbladder, removing it through an umbilical incision. He lavaged the gallbladder fossa with normal saline and left 100-200 mls in situ. The claimant's post-operative recovery was uneventful and she was discharged home the following morning.
However, the claimant awoke three days later with tremendous pain in her right upper quadrant and epigastrium, unrelieved by analgesia. She was admitted to A&E and a differential diagnosis of a bile leak or pancreatitis was made. The defendant took over care of the claimant and ordered a CT scan, which did not show any evidence of a bile leak. Over the next two days, the claimant remained in pain and her liver function tests became abnormal, such that the defendant suspected she might have a retained stone in her CBD. He planned for antibiotics and an endoscopic retrograde cholangiopancreatogram (ERCP) but, unfortunately, this procedure had to be abandoned because of the claimant's anxiety.
A further two days later, the defendant performed the ERCP himself. The cholangiogram revealed extravasation of contrast from the biliary tree into the gallbladder fossa, which the defendant thought suggested a cystic duct leak. An abdominal ultrasound scan later that afternoon revealed 'intraperitoneal leak of contrast from the biliary tree in the region of the confluence of the right and left hepatic ducts' with 'appearances in keeping of a biliary leak from the region of the stump of the cystic duct'. The defendant inserted a stent, opting not to perform a full sphincterotomy.
The next day, the claimant was afebrile, drinking normally and eating a little. The following day, she had some nausea and mild abdominal pain. Thereafter, her symptoms deteriorated, her liver function tests became increasingly deranged and she developed acute renal failure. The defendant at this point was on holiday and the claimant was transferred to a high dependency unit, following which she underwent a laparoscopy that revealed seven litres of bile in the peritoneal cavity. It was not possible to undertake biliary reconstruction because of the friable nature of the tissue, so a specialist hepatobiliary surgeon inserted multiple drains; he also noted in his operation note that there appeared to be a loss of tissue from the anterior wall of the CBD with the stent visible in the main CBD.
Thereafter, the claimant made a slow but steady recovery and was eventually discharged home a month later. A further three months later, the stent was successfully removed.
It was agreed that the claimant's post-operative symptoms were consistent with a bile leak, and the three main issues the court had to consider were: 1) the location of the bile leak; 2) the cause of the bile leak; and 3) whether there was negligence.
The claimant contended that the leak was from the CBD, while the defendant contended it was from the stump of the cystic duct. On the evidence, the judge agreed with the claimant.
The positioning of the stent was crucial: the defendant's ERCP note stated that he placed the stent in the CBD; the extravasation of contrast at ERCP supported a CBD leak and the defendant accepted this was possible; the defendant's expert was erroneous in thinking that the cystic duct drained into the common hepatic duct rather than the anatomically higher right hepatic duct, away from the contrast extravasation; the subsequent ultrasound noted 'the CBD stent is seen in situ'; the stent was probably not long enough to reach the right hepatic duct; and the stent might only exceptionally rarely have migrated up to the right hepatic duct.
Additionally, the specialist surgeon had noted anterior CBD tissue loss and the defendant's expert accepted it was unlikely the cystic duct would be anterior, and this fact had not been documented by the defendant; the absence of a stricture a year later was not relevant because strictures could develop up to 15 years later; symptoms of a CBD injury typically present after three to four days and rarely within 24 hours post-operatively; the defendant's own evidence was that the Hem-o-lock clips that he used were better than metal clips and that he had never known one come apart; and, while ischaemic necrosis was a theoretical possibility, it was unlikely because, as the experts agreed, the anatomical area had a rich blood supply.
The claimant claimed that it was an iatrogenic injury to the CBD, while the defendant argued that it was a clip falling off the cystic duct, either due to mechanical failure or ischaemic necrosis. The experts agreed that, if the defendant was correct, the cause was non-negligent.
The defendant confirmed that he had used mainly blunt dissection, but also had used diathermy. He accepted that there was a risk of excessive diathermy use and of excessive traction. Having determined the likely location of the leak as the CBD, the judge rejected the cause as possibly being clip failure or cystic duct stump necrosis, and concluded that the likely cause of the leak was, on the balance of probabilities, iatrogenic, from one of the three mechanisms postulated by the experts.
If the leak was iatrogenic, the experts were agreed that possible mechanisms of injury were diathermy, laceration by a sharp instrument or traction. Having determined that the CBD injury was iatrogenic, the final issue for the judge was: which of these was the mechanism and was it negligent?
The claimant's expert stated that, in the circumstances of a non-inflamed gallbladder, the injury was avoidable. The defendant's expert declared that he did 'not believe that all bile duct injuries are negligent and that some bile duct injuries are an unavoidable risk' and that 'there was no evidence that the operation was carried out negligently'. The defendant argued that the claimant was putting forward a case of res ipsa loquitur: if there was a bile duct injury, the defendant must have been negligent as iatrogenic injury is, in itself, evidence of negligence. The defendant submitted that there was no evidence of any error of surgical technique and medical literature demonstrated that a CBD injury was a recognised non-negligent risk of laparoscopic cholecystectomy.
The judge, having regard to Ratcliffe v Plymouth and Torbay Health Authority and Ors  Lloyd's Rep Med 162, rejected the assertion that this was a res ipsa loquitur argument. Nor did he accept that CBD injuries are always non-negligent, noting that the claimant's expert accepted that there are risks in surgery no matter how careful the surgeon is (which is why patients are asked to sign consent forms), concluding that 'it would be a novel proposition that a consent form absolves a surgeon from his duty of care'. The judge concluded that the claimant's case was that CBD injuries are avoidable by competent surgeons acting with normal care in uncomplicated cases, and that this was an uncomplicated case. The judge noted that even the defendant's expert '“ in saying 'I do not consider that iatrogenic bile duct injury in every circumstance is due to a negligent action by the operating surgeon. When there is very abnormal bile duct anatomy'¦ the likelihood of bile duct injury in the hands of a competent surgeon is high' '“ seemed to accept that there were circumstances in which a CBD injury could be caused negligently.
The judge concluded: 'As the defendant was carrying out an uncomplicated procedure some distance from the site of the common bile duct injury, and no explanation has been provided as to how such an injury could have been occasioned other than due to a want of care on the defendant's part, my conclusion is that the defendant negligently caused the injury.' On balance, he concluded that it was the diathermy that was the most likely culprit.
In relation to the second allegation, the judge also found against the defendant. Breach having been established, there was no argument about causation, and the claimant was awarded £92,931 in compensation.
A case of res ipsa loquitur?
The defendant in this case claimed that the claimant was relying on the legal maxim of res ipsa loquitur. As noted by Brooke LJ in Ratcliffe, in its purest form the maxim applies 'where the [claimant] relies on the 'res' (the thing itself) to raise the inference of negligence, which is supported by ordinary human experience, with no need for expert evidence'; for example, a surgeon cutting off the right foot instead of the left. However, Brooke LJ accepted that, in practice, in contested medical negligence cases, the claimant's evidence 'is likely to be buttressed by expert evidence to the effect that the matter complained of does not ordinarily occur in the absence of negligence'. At the close of the claimant's evidence, the judge would be entitled to infer negligence unless the defendant adduced evidence that discharged this inference, which could be achieved either by providing a plausible, but not a theoretical or remotely possible, non-negligent explanation of what happened (which does not need to be more likely than any other explanation) or by demonstrating that, on balance, there was proper care.
In the instant case, the defendant argued that the claimant's case was based on the argument that a bile duct injury during a laparoscopic cholecystectomy must be negligent, applying the maxim. In determining whether this was so, the judge would have considered whether the fact that the claimant suffered an unexpected bile leak during the operation established a prima facie case of negligence against the defendant, as per Ratcliffe; the judge, however, disagreed with the defendant and did not consider the case to be one of res ipsa loquitur.
It is, though, arguable that, in the context of an uncomplicated laparoscopic cholecystectomy, once the claimant had established that the leak had occurred from the CBD, and with no apparent cause for the leak, it was open to the judge to infer that the procedure must have been performed negligently so as to cause an iatrogenic injury, thus necessitating that the defendant demonstrate either that there was a possible non-negligent explanation for the injury or that he carried out the operation with all due care, both of which he failed to do.
So, while this case may not be a demonstration of the maxim in its purest form, it is difficult not to think that, where there is injury to the CBD in an uncomplicated laparoscopic cholecystectomy, there could be an inference of negligence to be rebutted by the defendant.