Alison Winterbotham v Dr Arash Zaker Sharak

In clinical negligence claims concerning consent, the professional practice test does not determine whether material risks or reasonable alternatives should be disclosed. The clinician must take reasonable care to ensure that the patient understands material risks and reasonable alternative treatments. Materiality is fact-sensitive and includes the nature and consequences of the risk, available alternatives and the patient’s circumstances. A signed consent form is not sufficient where the required dialogue has not occurred.

Whether an alternative treatment is reasonable may involve clinical judgment assessed by the professional practice test. Where a patient would have deferred surgery after receiving an adequate warning of a material risk which then materialises, the modified causation principle in Chester v Afshar may apply.

The claimant underwent extraction of a lower right wisdom tooth by the defendant oral surgeon. The extraction damaged her lingual nerve. The extraction itself was not alleged to have been performed negligently. The claim concerned failure to explain the increased risks of nerve injury, failure to discuss a possible cone beam CT scan, and failure to offer coronectomy as a lower-risk alternative.

The claimant alleged that, if properly advised, she would have undergone a coronectomy or deferred treatment. The defendant contended that she would have undergone the same extraction and suffered the injury in any event. The court determined breach, informed consent, causation and damages.

1. Breach and informed consent. The defendant breached his duty by failing to provide the guidance note, provide a meaningful opportunity for questions, explain the material risks, identify the extraction as high risk, and explain coronectomy as a reasonable alternative with a lower risk of nerve injury.
2. The Bolam professional practice test applied to clinical assessment and treatment issues. It did not determine the content of the duty to obtain informed consent. Applying Montgomery and Duce, the clinician had to explain risks which a reasonable patient in the claimant’s position would find significant, or which the clinician should reasonably have appreciated she would find significant.
3. The claimant’s distoangularly impacted tooth created an increased risk to the lingual nerve. The proximity of the roots to the inferior alveolar canal meant that a CBCT should at least have been offered. Reliance on the traditional radiological signs alone was not logically sustainable in the circumstances, applying Bolitho.
4. Coronectomy was a reasonable alternative treatment. Its risks, including the possibility of revision surgery, and its lower risk of nerve injury should have been explained. The signed consent form could not establish informed consent because it did not replace the necessary discussion.
5. On the balance of probabilities, proper advice would have led the claimant to obtain a CBCT and choose coronectomy. She therefore avoided the nerve injury. Alternatively, she would have deferred the extraction. The modified causation principle in Chester v Afshar applied because the material risk which was inadequately explained subsequently materialised. The principle did not extend to a failure to advise about alternative treatment, for which ordinary causation applied.
6. The claim succeeded. Damages were assessed at £265,000.