Blunt dissection

An update from a regular series written by Mr Robert Wheeler, director, department of clinical law, where he considers various aspects of clinical law that our nursing staff, medical staff and other professions rely on when caring for patients.

Surgeons fond of open surgery often opine that their fingertips are safer instruments than those made of metal; there is at least one judgment in the common law that tests this assumption. In a case where a woman had suffered a femoral nerve injury during a fistula repair, the court had to balance the evidence relating to competing potential causes of harm.

Mrs O’Connor originally underwent hysterectomy when she was forty; regrettably suffering a subsequent vesico-vaginal fistula. To deal with this, a urologist reopened her Pfannansteil wound and placed a Turner-Warwick ring retractor to maintain access. He then reflected the sigmoid colon, which was ‘…badly stuck to the vaginal side of the fistula which was then excised… allowing the vagina to be dissected off the back wall of the bladder.’ In Recovery, she found that her left leg was numb, with loss of movement. Latterly, pain developed. Nerve conduction studies revealed ‘…markedly severe left femoral neuropathy due to axon loss’. The fistula repair was otherwise successful.

Mrs O’Connor had undergone a 15-minute cystoscopy in the lithotomy position, and bilateral rectus sheath and inguinal nerve blocks, but the court found that these were unlikely causes of her injury; her BMI being low. The judge found that the two main likely causes of the injury were either an injury related to the placement of the retractor blades, or the blunt dissection of the fistula causing trauma to the elements of the femoral nerve within the psoas muscle. Since the court was later told that the blades of the retractor were insufficiently long to provide deep retraction, the High Court decision was that ‘…some form of blunt trauma injury’ was caused to the nerve, indicative of substandard care. This decision was appealed by the hospital to the Court of Appeal, partly on the grounds that the judge had erred in finding that dissection had damaged the nerve. The hospital did not appeal on the grounds that damage caused by dissection is not by itself indicative of substandard care.

The court was told that the surgical field was between 1-5 cm from the nerve, and that whilst femoral nerve injury was unlikely during vesico-vaginal fistula division, it remained ‘a possibility’: particularly in the context of the sigmoid colon’s adherence to both the pelvic and vaginal walls. Expert evidence suggested that rather than causing bruising or ischaemic damage to the psoas muscle, ‘…bruising it, haematoma, ischaemia or whatever else during the dissection process…the femoral nerve remains lateral, just slightly lateral to the psoas muscle…’ The appeal court was led to a letter written by the surgeon four months after the surgery, in which he conceded that he ‘…may have caused some form of trauma to the femoral nerve during the difficult task of dissecting the sigmoid colon.’ The Court of Appeal dismissed the hospital’s appeal, noting that there was ‘…no dispute that if the surgeon directly injured the femoral nerve during the dissection…’ this would equate to substandard care.

Such close analysis of factual evidence is unusual in appellate courts, who generally limit themselves to the legal process involved in reaching a decision in the lower court.

One would hope that if a case with similar facts emerged today, someone might suggest to the court that dissection, blunt or otherwise, can sometimes be difficult. After all, that is why during the preoperative disclosure of risks, patients are made aware of potential intraoperative damage to contiguous structures, the occurrence of which is not necessarily, on the balance of probabilities, indicative of substandard care.

O’Connor v The Pennine Acute Hospitals NHST [2015] EWCA Civ 1244

Mr Robert Wheeler
Department of clinical law
November 2025