Correia v University Hospital of North Staffordshire NHS Trust [2017] EWCA Civ 356: where are the limits to the Chester v Afshar exception to causation?

In this blog Isaac Hogarth of 12KBW discusses the recent judgment of the Court of Appeal which considers the limits of the causation principles set down by the House of Lords in Chester v Afshar.

The Facts

The claim arose from the surgical treatment of a painful recurrent neuroma (benign tumour of the nerve tissue) in the appellant’s right foot.

On 10 January 2008, she attended a consultation where she was advised that the surgery would consist of three stages (1) exploration to locate the suspected neuroma, and neurolysis (a separation of the nerve ending from the neuroma if it were found), (2) excision of the neuroma, and (3) the nerve ending either tied or buried, depending on the available length of the nerve.

The appellant agreed to the operation.

On the day of the operation, 5 November 2008, the appellant spoke with the consultant’s registrar for the purpose of giving consent for the procedure, and the consent form was signed. The consent form made no reference to nerve relocation following excision of the neuroma.

It was common ground that relocation was a necessary part of the surgical process if a neuroma were located and excised. The consultant surgeon’s evidence at trial was that he believed he had carried out a relocation procedure. That evidence was rejected, and was not appealed.

It was therefore common ground on appeal that the operation was performed negligently.

However, it was also found that that negligence was not causative of damage sustained, which finding was on the basis of the joint statement of both parties’ pain experts.

The Appeal

There were two issues on appeal:

  • The informed consent issue:

In relation to the issue of informed consent, the appellant argued that the case fell within the exception to the normal causation rule as set out in Chester v Afshar [2004] UKHL 41; [2005] 1 AC 134. She argued that she had given consent to an operation which involved a three-stage procedure and had not been warned of the material risks of an operation which omitted the third and crucial step of relocation.

It was argued that if the appellant could bring herself within this Chester exception, she would not have to show that the respondent’s negligence caused the damage (which was an issue on which she lost at trial).

  • The causation issue:

This was a challenge to the trial judge’s rejection of the evidence of the appellant’s plastic surgeon in favour of the evidence of the pain experts. This challenge failed, and is of no wider interest.

The Court of Appeal’s Judgment

Simon LJ summarised Chester v Afshar as follows:

  1. … the defendant neurosurgeon advised the claimant to undergo an operation on her spine but failed to explain that, if performed without negligence, the procedure carried a small (1-2%) unavoidable risk of a neurological damage leading to a disabling condition. The claimant agreed to the procedure on a Friday and the operation was performed the following Monday. She subsequently developed the disabling condition which left her partially paralysed and sued the surgeon for negligence…
  2. It was common ground that, whenever the operation was carried out, the same small percentage risk of resulting disability would exist, and that in the light of the degree of risk, the probabilities were that the disabling condition would not arise. The point was expressed by Lord Hope of Craighead at [61]:

“…the failure to warn cannot be said to have increased the risk of injury. the risk was inherent in the operation itself… the evidence indicated that it was also liable to occur at random, irrespective of the degree of care and skill with which the operation was conducted by the surgeon. This means that the risk would have been the same whenever and at whoever’s hands she had the operation.”


  1. Each of [the majority] endorsed the opinions of the other; and in my view the ratio of the decision is contained in [87] of Lord Hope’s opinion. If there has been a negligent failure to warn of a particular risk from an operation and the injury is intimately connected to the duty to warn, then the injury is to be regarded as being caused by the breach of the duty to warn and this is to be regarded as a modest departure from established principles of causation.

Simon LJ (at [26]) noted that the trial judge had found that there was no justifiable complaint about the process of consent up to the moment when the operation began. The negligent omission of the third stage did not negate consent. It did not make the operation different for the purposes of consent, or require specific consent. The appellant made an informed choice to have the surgery, and the injury was not ‘intimately linked’ with the duty to warn.

Simon LJ went on the say (at [28]) that the “crucial finding” in Chester was that if the appellant had been warned of the risk, she would have deferred the operation, such that it could be said that it was not likely that the same risk would materialise on the next occasion.

In this particular case, he noted that it was not a part of the appellant’s evidence that she would have delayed the operation or gone to another surgeon, had she been warned of the risk.


This was never really a case about the Chester exception. The attempt by the appellant’s legal team to bring the case within that principle was a means of attempting to circumvent the trial judge’s reasoned findings on causation, on the basis of which the claim had failed.

To say (1) that a surgeon ought to warn of risks that may arise from his negligent performance of surgery, where on the respondent’s evidence, breach was denied and (2) that had the appellant been warned of such unanticipated risks, she would not have proceeded with that surgery with that surgeon, is not convincing. It would mean that any unanticipated breach during an operation would immediately being a case within the Chester exception as the claimant would not have given consent, and would obviously, if given the option have preferred not to proceed.

There will be many ways in which negligence may occur during an operation, and many of them cannot be, and will not have been, anticipated. The Court of Appeal’s finding that the negligent failure to perform the third stage of the surgery did not negate the consenting process, and in particular that this was not an operation in respect of which specific consent for this risk was needed, are clear and helpful findings.

Very significantly, Simon LJ stated (at [28]) that if a party wishes to rely on the principle in Chester, it is necessary to plead the point and support it by evidence. This is sensible, and will force both sides in such a case to consider the key elements of a claim under this exception at an early stage. In particular: (1) whether the risk was one inherent in the surgery such that the injury was ‘intimately linked’ with the duty to warn; (2) whether the claimant would have gone ahead with the same procedure at the same time had a warning been given. Claimants should be alive to the fact that any claim made relying on the Chester exception should be specifically pleaded, to avoid pleading points being taken.

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