NSW Supreme Court Considers Inherent Risk and Peer Professional Opinion in Bariatric Surgery Case Polsen v Harrison (No. 8)

22 Juli 2023

On 6 July 2023, Lonergan J found in favour of Dr Harrison (Defendant), in a complex bariatric surgery case brought by Katrina Polsen (Plaintiff). A full decision can be read here.


On 22 July 2013, the Plaintiff underwent a sleeve gastrectomy procedure performed by the Defendant to manage her morbid obesity. She developed an early post-operative leak, which required her to return to theatre for a laparoscopic washout and insertion of peritoneal drain. She subsequently had a difficult and complex post-operative course due to intermittent sepsis and malnutrition, involving many admissions to hospital and multiple surgical procedures over the following five years.

The Plaintiff’s case was brought on the following grounds:

  1. Given her comorbidities of long-term alcohol abuse and liver dysfunction, she should have been counselled and the elective non urgent surgery delayed.
  2. Alternatively, Dr Harrison did not properly warn her of the risks and if he had, she would not have gone ahead with the procedure.
  3. Alternatively, Dr Harrison’s technical performance of the operation and initial management was negligent and that negligence caused or materially contributed to a gastric leak at the site of the surgery, causing ongoing illness and the need for the further surgeries.

In response the Defendant denied that the treatment was negligent and claimed:

  1. He acted in a manner that was widely accepted in Australia by peer professional opinion as competent professional practice and as such he was not liable pursuant to section 5O of the Civil Liability Act (2002) NSW (the Act).
  2. The complications and post-operative course were consistent with the inherent risks of the procedure and, as such, he was not liable pursuant to section 5I of the Act.

The Supreme Court Decision

Lonergan J found that the Plaintiff’s evidence of her significant alcohol consumption prior to the procedure was unreliable. If her evidence was a true reflection of her alcohol consumption, then she had misrepresented to all the medical professionals her level of alcohol consumption during 2012 and 2013.

The experts retained by the Plaintiff offered their views based on the assumption that she had told the Defendant that she was consuming a bottle of wine a night (rather than one standard drink as recorded in the notes). The evidence was so unsatisfactory on this issue that no such assumption could be made. Any expert opinion reliant on that assumption was disregarded.

There was no failure to warn of the many risks of the gastric sleeve procedure and she was comprehensively warned of those risks, including a gastric leak and sepsis. 

The Defendant’s surgical approach and technique was appropriate and the Plaintiff was an appropriate candidate for surgery. To the extent that the expert opinions suggested that she was an inappropriate candidate for surgery or surgery should have been delayed, Lonergan J rejected those views.

The decision was as follows:

  1. The Defendant acted in a manner that, at the time his professional service was provided, was widely accepted in Australia by peer professional opinion as competent professional practice. This was clearly established on the evidence of Professor Brown and Dr Garett Smith (the Defendant’s bariatric experts). As such, the Plaintiff’s case failed.
  2. There was no need to consider whether the Defendant was negligent under sections 5B and 5C of the Act. On the basis of other New South Wales case law when section 5O is invoked, the effect is that it provides a complete answer to the claim (rather than a defence once the issue of negligence has been determined).
  3. The Plaintiff did not prove causation although there was no need to consider that question.
  4. The Defendant established that the complicated post-operative course that followed the Plaintiff’s sleeve gastrectomy was within the risks inherent in the procedure.
  5. There was no failure to warn of the many risks of the gastric sleeve procedure and the Plaintiff was comprehensively warned of the many risks.

Implications of the Decision

Though a NSW decision, the decision is of interest in Victoria due to the parallels with Victorian legislation.

Some key takeaways are as follows:

  • The standard of care for professionals set out in section 5O of the Act is largely replicated in section 59 of the Wrongs Act (1958) VIC. The decision highlights the need to consider whether a section 59 defence should be pleaded and the subject of expert evidence.
  • The Defendant proved that pursuant to section 5I of the Act the Plaintiff’s stormy post-operative course was encompassed by the recognised risks of the procedure, of which she was warned. This section is largely replicated in section 55 of the Wrongs Act (1958) VIC. The decision highlights the need to consider whether a section 55 defence should be pleaded even in circumstances where the inherent risk is complex and suffered over a significant period following the procedure.
  • Expert opinion based on assumptions not supported by the evidence was disregarded. When assessing the strength of expert evidence, the assumptions on which the evidence is based are crucial.