Mills v Oxford University Hospitals NHS Trust

In clinical negligence, the Bolam test applies to the choice and performance of surgical technique, subject to the requirement in Bolitho that supporting professional opinion has a logical basis. A doctor’s duty to obtain informed consent under Montgomery requires discussion of material risks and reasonable alternative or variant treatments. This includes a newer technique’s limited adoption, uncertain risks and material disadvantages compared with a conventional technique. The court must assess causation on the balance of probabilities. Where the warned risk materialises, the injury may fall within the scope of the duty even if an alternative causative route is disputed.

Mr Mills suffered a haemorrhage and stroke during resection of a left frontal glioma. He alleged that the operation was performed negligently and that the Trust failed to obtain informed consent. The alleged breaches included use of a minimally invasive endoscopically-assisted open craniotomy, migration into midline structures, failure to discuss surveillance and biopsy, failure to explain that the tumour was unlikely to cause his headaches, and failure to discuss microscopically-assisted surgery as an alternative.

The Trust admitted that the alternative surgical technique had not been discussed. The court determined liability only, applying Bolam and Bolitho to performance of the operation and Montgomery to informed consent.

1. Clinical negligence. The use of the minimally invasive endoscopically-assisted technique was not negligent. A responsible, competent and respectable body of neuro-oncological neurosurgical opinion supported its use, notwithstanding contrary expert opinion. The court was not entitled to prefer one logically supportable medical view over another.
2. The claimant failed to prove that the surgeon had migrated into the midline structures. The evidence of the assisting neurosurgeons, the absence of visible damage, the biopsy and postoperative scans, and the operative trajectory supported the conclusion that the stroke resulted indirectly from haemorrhage and pressure during attempts to control it. The clinical-negligence claim therefore failed.
3. Informed consent. Applying Montgomery v Lanarkshire Health Board [2015] UKSC 11, the duty required dialogue about material risks and reasonable alternative or variant treatments. The surgeon had discussed surveillance, biopsy and resection, together with their risks and benefits. There was no breach in that respect. However, he should have explained that the glioma was an incidental finding and was unlikely to have caused the headaches. That breach had no causative effect.
4. The surgeon breached the duty by failing to offer microscopically-assisted resection as an alternative and failing to explain the comparative risks and benefits. The patient should have been told that the endoscopically-assisted method was newer, not well established, less widely used, afforded more limited direct line of sight, might make bleeding more difficult to control, and had uncertain risks and benefits.
5. On the balance of probabilities, proper advice would have led the patient to choose the conventional microscopically-assisted technique. The court accepted that the initial limited access probably delayed control of the torrential bleeding and that earlier control would probably have avoided the stroke. The injury was also within the scope of the duty to warn because the risk of damage to a vessel outside the surgeon’s direct line of sight had materialised.

The claim based on clinical negligence failed. The claim based on informed consent succeeded.