KB-2023-001134 - [2025] EWHC 2121 (KB)

Preliminary Issue 3:was there a breach of duty in respect of informed consent and, if so, would the Claimant have opted to postpone her surgery in favour of awaiting a second opinion?

It is alleged that the Defendant was negligent in:

There are, therefore, two categories of allegations in relation to the consent process: (a) allegations as to the content of the discussions concerning the risks and mitigation measures and (b) an allegation as to the timing of the consent process, namely that it occurred too late, on the day of surgery.

It is also contended on behalf of the Claimant (paragraph 53 of the Re-Amended Particulars of Claim) that had the risks of the procedure been properly and timeously discussed with the Claimant (and her family) and had they been given time to consider the risks, the Claimant (and her family) would have chosen to postpone the surgery in order to consider the risks and benefits of surgery with and without exposing and slinging suitable vessels. It is further contended that the Claimant (and her family) would probably have sought a second opinion and that the second opinion would have advised that precautions should be taken in the form of exposing and slinging suitable vessels.

Mr Elgot submitted that if surgery had taken place on a different day, then, on the balance of probabilities, the injury to the aorta would not have occurred, with reliance placed on Chester v Afshar [2004] UKHL 41.

Ms Power drew my attention to the Court of Appeal’s analysis in Correia v University of North Staffordshire NHS Trust [2017] EWCA Civ 356 at [28]: “…if a claimant is to rely on the exceptional principle of causation established by Chester v Afshar, it is necessary to plead the point and support it by evidence” per Simon LJ) and submitted that the Chester v Afshar point was inadequately pleaded.

In Correia the court noted, at [28], that “it was not the appellant’s case that she would not have had the operation, or would have deferred it or have gone to another surgeon”. In the present case, in contrast, it is pleaded that had the risks been properly discussed and had the Claimant been given adequate time to consider them then “the Claimant and her family would have chosen to postpone the surgery in order to consider the risks and benefits of surgery with and without exposing suitable vessels and placing slings around the artery”. Similarly, it is pleaded that the second opinion “would have been that precautions should be taken in the form of exposing suitable vessels…”. It is right to note, however, that the pleaded case concerning the seeking of a second opinion and delay of the surgery are confined to the allegation that the consenting process should have advised as to the possibility of exposing the femoral vessels as a form of risk mitigation. The position is sufficiently pleaded, in my view, to mean that it is appropriate for me to make the relevant factual (or counterfactual) findings on this issue, albeit that the parties are agreed that the legal analysis of the Claimant’s reliance on Chester v Afshar, is not a matter for determination at this stage.

It is contended on behalf of the Claimant that following the MDT decision on 15 December 2021 “for surgical PVR and PEARS +/- aortic valve repair/replacement” there should have been a letter to the Claimant explaining the MDT outcome and the plan for surgery, but no such letter was sent.

Dr Jansen was clear that she was not in a position to provide detailed information to the Claimant about the risks of the proposed surgery as she is not a surgeon and was not undertaking the operation. Her evidence was that it would have been her standard practice to call the Claimant after the MDT meeting on 15 December 2021, and she believes she would have done, but she does not have a note of having called the Claimant. She says that she would have explained that the Claimant “should expect to hear from the surgeons with regard to the waiting list and pre-operative assessments (including potential imaging)”.

When the Claimant attended for pre-assessment on 20 January 2022 she was seen by the consultant anaesthetist, but not by Mr Nassar, who was unavailable. The clinical notes for that day record: “Risks mentioned: infection (mainly chest, blood), need for prolonged ventilation, renal failure requiring RRT, prolonged ITU stay. She had no answer and is awaiting discussion with the surgeon to sign consent”. Under “Any issues to Flag” it is recorded: “not seen consultant - ? surgical plan – MN [Mr Nassar] not available today. Secretary contacted and will arrange consultant review – pending.”

In his first statement, Mr Nassar asserts that the Claimant was aware of the kind of surgery she might require as she had spoken to Dr Jansen and had “been on the waiting list for many months and had attended a pre-operative assessment”. Dr Jansen, however, was not the surgeon and not able to provide details in respect of the risks of the surgery. Only Mr Nassar was able to advise the Claimant on the risks of the surgery as only he, within the hospital, carried out the PEARS procedure. In fact, the Claimant was not seen by Mr Nassar until the morning of the surgery on 3 May 2022.

In the event, the surgery was initially expedited to 24 April 2022 and the Claimant saw Mr Mohamed on that day. According to Mr Mohamed’s witness statement, he used the Euroscore system to calculate the mortality risk, but he seems to have considered that the result (which he does not state) was an underestimate; he says that he “ended up quoting a mortality (risk of death) of around 20%. This was a very considerable risk and I remember was one which [the Claimant] specifically asked about. She asked me why it was that high. It was higher than she had been expecting and she was quite shocked. I discussed with her that I considered she was higher risk than normal cardiac patients because she had previously had other interventions so was likely to have adhesions in her chest”. Mr Mohamed’s evidence was that “the Claimant accepted all of the risks discussed, including a 20% risk of death, and had no further questions during our appointment”.

Mr Nassar says that he offered to speak to the Claimant before she left hospital on 24 April but she “declined to wait”. I am not satisfied, on the very limited evidence before me, that the Claimant had been informed that it was the surgeon who wanted to speak to her. In any event, and as Mr Yap emphasises, this is unlikely to have been an opportune moment to discuss the risks of the surgery given that it is likely that the Claimant would have been distressed at that point in time by the last minute cancellation of her surgery after having gone through the inevitable anxiety of preparing herself for a major operation.

The evidence of the Claimant’s husband was that “we would have wanted to take reasonable steps to see what could be done to minimise the risks of surgery” and “[i]f it had appeared to us that the surgeon was reluctant to take steps to minimise the risks we would have wanted at the very least a second opinion and we might have delayed the surgery until we were firmly of the understanding that we understood the risks and that they were going to be limited to a reasonable level”.

On 2 May 2022 the Claimant was re-admitted to the Freeman Hospital for planned surgery by Mr Nassar on the following day. In his first statement Mr Nassar does not say when he saw the Claimant to go through the consent process. However, given that 2 May was a bank holiday Monday, Mr Nassar accepted in his oral evidence that he probably only saw the Claimant on the morning of Tuesday 3 May. The consent form is dated 3 May 2022.

Mr Nassar says that he completed a new consent form with the Claimant and would have gone through each of the ten risks set out on the consent form, which included the risk of mortality, as well as explaining, in re-do cases, that “the heart is stuck to the back of the breast bone and that the first part of the operation is to free the heart from the bone. I say to them that if the first part of the operation goes well, then the overall risk of death reduces from 10% to around 2-3%. I would discuss that if anything went wrong in surgery, they may end up in intensive care with machines helping to keep them alive. I would warn them that sometimes they may wake up with an incision in their groin if we have been required to start the heart lung (cardiopulmonary bypass) machine through the groin vessels. I would always give my patients the opportunity to ask questions and clarify anything that they were unsure about”.

The clinical records contain a “Cardiothoracic Surgery Ward Round Note” recorded as being timed at 09:22 on 3 May 2022 which includes the following:

“Consultant Leading Ward Round

ACHD ward round – MN, KJ, ACHD nurse specialists

Plan and requested actions

…

-

New consent form signed

-

Await transfer to theatre”

It is apparent from the Claimant’s disclosed WhatsApp messages, that she texted her mother at 09:14. Prior to this point in time, there is no suggestion in her texts that the Claimant had been seen by a surgeon and, indeed, her texts demonstrate that she was acutely worried that the operation might be cancelled for a second time. She then texted again, at 09:17, to state: “All the surgeons just come in its going a head so next 2 hours they will come for is [sic]”.

These texts are consistent with the timing of the note of the surgery ward round. The texts, read with the ward round note, suggest that Mr Nassar may have spent a maximum of about 3 minutes with the Claimant in the ward round, that is, the period of time which is bookended by the Claimant’s two texts of 09:14 and 09:17. This also seems to have been when the second consent form was signed given the entry (timed at 09:22) on the Ward Round Note: “new consent form signed”. Mr Nassar has not suggested that there was any different occasion on which he took additional time to see the Claimant and to explain the benefits and risks of the proposed surgery with her.

The ward round note records Dr Jansen as having been in attendance. She says this in her statement: “I did see [the Claimant] very briefly when she was admitted to the ward prior to going into theatre”. The description “very briefly” seems to be consistent with the three-minute timing referred to above. She provides no evidence in her statement as to the consent process undertaken by Mr Nassar.

There are no other contemporaneous records relating to the consenting process. Mr Elgot notes that the lack of other contemporaneous records providing further details of the consenting process is at odds with the RCS guidance cited at [62] above.

The consent form signed by the Claimant on 3 May 2022 states that there was a 5-10% risk of mortality. There is no contemporaneous record of the Claimant being informed that her enlarged aorta was closely proximate to the rear of the sternum, nor that she was informed of the risks that this posed. Mr Nassar accepted in cross-examination that the aorta was “close” but not adherent and that the closer it is to the sternum, the higher the risks of the surgery. As noted at [121] above, this is somewhat at odds with his assertion that there was no reason to anticipate that this surgery would be any more difficult than other re-do sternotomies. Mr Nassar’s evidence is that he nevertheless considered Dr Mohamed’s risk assessment to overestimate the risk of mortality and that he tore up Dr Mohamed’s consent form as he did not want there to be two different risk assessments on file because this might cause confusion. Mr Nassar agreed with Mr Elgot’s statement that he should simply have put a line through the first consent form, rather than ripping up a medical record.

It is possible that Mr Nassar reviewed the CT imagery on the morning of 3 May 2022 before the ward round and before undertaking the consenting process, but it was clear to me that Mr Nassar did not have any specific recollection of the sequence of events in this regard.

Mr Nassar’s evidence is that he would not discuss with a patient the possibility of exposing groin vessels as a means of facilitating an emergency bypass in the event of damage to the aorta. He said that this level of detail was not appropriate and that he is not aware of any colleagues who would have such a discussion. He also stated that “it is important that my patients know about the risks of serious injury or death, but it is not necessary to discuss with them the mode of death. They are (understandably) usually extremely anxious about the surgery”.

Dr Jansen explains that had the Claimant sought a second opinion then she would have been happy to support and to try to find another surgeon, but that the Newcastle Freeman is “generally the last stop” with patients being referred to it, rather than the other way around as it is regarded as a centre of excellence.

As to the issue of the timing of the consent process, in their joint statement the experts agreed that “in an ideal world complex surgery should be discussed in an outpatient clinic with the operating surgeon”. Mr Yap’s evidence was that it was “unthinkable” that the Claimant was not offered an outpatient consultation with the operating surgeon to discuss the benefits and risks of the proposed operation given its complexity.

Mr Roberts considered that, taken as a whole, the Claimant had been given enough information to enable her to understand the major risks and benefits of the proposed surgery and, in any event, there was no other suitable surgical options for her. He also emphasises that there was a 7 day period between the original consenting process undertaken by Mr Mohamed on 24 April and the second admission on 2 May and then a further consenting process by Mr Nassar.

As to the content of the risk assessment in terms of the risk of mortality, the experts both used the Euroscore calculation method to estimate the risk of mortality and agreed that this comes out at either 6% or 9% depending on whether one is estimating for the known two procedures (“surgical PVR and PEARS”) or also including the third possible procedure (“+/- aortic valve repair/replacement”).

As to the possibility of exposing the femoral vessels in advance of the sternotomy, Mr Roberts’ evidence was that a reasonable body of cardiac surgeons would not discuss the details of cannulation for bypass and emergency cannulation strategies with patients. He says that it is not part of his practice and he is not aware of any cardiac surgeon who discusses cannulation strategies about re-do sternotomy as part of the consent process. In their joint statement, both experts agreed that details of cannulation strategies would not be discussed with patients as part of standard practice unless the patient asked.

The experts also agreed that if a patient ever asks for a second opinion and wants to cancel surgery whilst this second opinion is obtained, then all reasonable surgeons would facilitate this. Mr Yap makes the point that there are seven other congenital heart surgery units in the UK and it would have been easy to ask for a second opinion. He states that the relevant units at St Bartholemew’s Hospital and Great Ormond Street Hospital have weekly MDT meetings, held virtually, and discuss patients from the UK and abroad.

I do not consider that there was a breach of duty on the part of the Defendant in “delegating” the consenting process to Mr Mohamed on 24 April 2022. The evidence indicates that Mr Mohamed was an experienced clinician and, as Mr Nassar’s registrar, it seems likely that he had an adequate understanding of the intended surgery. In any event, if the surgery had not been cancelled on 24 April then it seems likely that Mr Nassar would have reviewed the consent form prior to operating, as he did on 3 May 2022, and would then have seen the Claimant to inform her that, in his opinion, the risk of mortality was 5-10% rather than 20%.

In terms of the specific information imparted to the Claimant, the consent form of 3 May 2022 records a risk of mortality of 5-10% and this is broadly consistent with the estimation arrived at by both experts, namely 6-9%, derived with the assistance of Euroscore. Insofar as it continued to be argued on behalf of the Claimant that inadequate information was given to the Claimant by Mr Nassar as to the risk of mortality of the proposed surgery, I do not accept that there was any breach of duty on the part of the Defendant in this regard.

I am troubled by Mr Nassar’s actions in tearing up the previous consent form which the Claimant signed on 24 April 2022. Had it not been possible to obtain a statement from Mr Mohamed and/or had he forgotten the details of his assessment of the risk, then it is possible that the facts of the April consent process would not have been before this court. Mr Nassar was not able to justify his actions in destroying this clinical record and he accepted that he could, and should, have made clear that it was superseded by drawing a line across the consent form or otherwise marking it as an obsolete form. However, there was no pleaded breach of duty in relation to this issue and, in any event, the advice which Mr Nassar did in fact give in respect of the risks of the surgery, including of mortality, was not, in my judgment, negligent; whether any regulatory issues arise from the destruction of a medical record is a separate matter.

The other aspect of the Claimant’s pleaded case on the content of the consent process was the allegation that Mr Nassar was in breach of duty for failing to explain the steps which could be taken to mitigate the risk of mortality or serious injury posed by the proposed surgery. In particular, it is alleged that Mr Nassar should have explained that there was an option of exposing the groin vessels in advance of the sternotomy in order to facilitate emergency cardiopulmonary bypass should it be required.

As set out at [188] above, Mr Nassar’s clear evidence was that he would not provide this level of detail to a patient about possible risk mitigation. Mr Roberts’ evidence was that a reasonable body of cardiac surgeons would not discuss the details of cannulation for bypass and emergency cannulation strategies with patients. In the joint statement, the question answered by the experts was whether it would be standard practice to discuss the steps to be taken “in the event of aortic injury”. The question posed in the joint statement did not ask, in terms, whether a surgeon should discuss the options which might be taken in advance of the sternotomy to mitigate the injury that might be suffered in the event of aortic injury. However, it is clear that neither Mr Yap nor Mr Roberts considered that a surgeon would typically explain that there was an option to expose the femoral vessels in advance of the sternotomy.

In circumstances in which I have found that it was negligent not to expose the femoral vessels in advance of the sternotomy given the medium to high risk of aortic injury in this case, it follows, in my judgment that it was negligent not to advise the Claimant that exposing and preparing the femoral vessels was a variant form of the standard sternotomy procedure and one which, in the Claimant’s circumstances, was appropriate in light of the risks.

However, if I am wrong in my assessment that the Defendant was negligent in failing to expose the femoral vessels, then the issue does arise as to whether the Claimant should nevertheless have been advised of the fact that the sternotomy could be carried out either with the femoral vessels exposed and prepared, or not. This is an issue which goes to the question of the level of detail which a surgeon should provide to a patient in relation to the surgical procedure in order to enable the patient to make a properly informed decision.

A reasonable person in the patient’s position would, in my view, be likely to attach significance to the fact that the risk of mortality in this case was 5-10%, with a separate, and no doubt higher, risk of aortic injury. A patient who is informed that the procedure can be carried out with or without taking a step which may facilitate more rapid establishment of cardiopulmonary bypass in the event of aortic injury, is in a position to begin to ask questions to explore the pros and cons of the options and so give informed consent. The surgeon would then be likely to have to explain why they consider that one variant is more appropriate. No doubt, in such circumstances, Mr Nassar would have explained his reasons for concluding that it was not appropriate to expose and prepare the femoral vessels in advance (see [88] above).

The advisability of taking a step, such as this, to mitigate potential risks undoubtedly involves medical considerations, but not only medical considerations. As noted in Montgomery at [89], the nature of the risk, including the effect which its occurrence would have on the life of the patient and the importance to the patient of the benefits sought to be achieved may be of relevance, rather than merely the percentage chance of the risk materialising.

Whilst Mr Yap and Mr Roberts were of the view that details of cannulation strategy did not need to be discussed with a patient, it seems to me that they were both approaching this issue as one concerning the technical details of the surgery, rather than asking themselves whether a patient should be informed as to the existence of a variant of a surgical procedure which has the capacity to reduce the risk of death and/or permanent brain injury in the event that the foreseeable and known risk of aortic injury eventuates. It was agreed by all the surgeons that the assessment of the risk of aortic injury should inform the decision as to whether the femoral vessels should be exposed in advance of sternotomy. The difference between the surgeons was whether the risks in this case warranted such a step being taken.

The Claimant was in her mid-twenties with three young children; whilst she was prepared to take the risks inherent in the surgery given the absence of any real alternative options, had she been informed that steps could be taken to minimise the risk of death or permanent brain damage in the event of aortic injury then she may have consented to the surgery, but only provided that such steps were taken. The very process of being required to explore the risks of the surgery and the options to mitigate those risks with the patient, and to hear the concerns and questions of the patient, may itself inform the thinking of the surgeon. The GMC and RCS guidance set out at [62] and [63] above and, further, the GMC guidance quoted in Montgomery at [77], emphasises the collaborative nature of the consent process and the need to try to reach a shared understanding of the expectations and limitation of the available options. Even where the surgeon continues to recommend one particular course over another, the patient is at least equipped to decide whether to proceed on the recommended basis or whether they wish to seek a second opinion.

When one is dealing with surgery such as this, which involves a risk of mortality of 5-10% for a young patient with three young children in a case in which the patient’s enlarged aorta was proximate to the rear of the sternum, leading to a real risk of aortic injury, I can see no good reason why a surgeon should take it upon themselves to determine whether a risk-mitigation step of this nature should or should not be taken without first discussing the availability of the option with the patient as part of the consenting process. To the contrary, as identified in Montgomery,at [83], the patient has an entitlement to decide on the risks to her health which she is willing to run. It is not for the surgeon to determine, for the Claimant, what the Claimant’s risk appetite should be. In all the circumstances of this case, it was, in my judgment, a breach of the duty of care owed by the surgeon not to explain to the Claimant that an option was available which might mitigate, to some extent, the risks consequential upon the inherent risk of aortic injury.

In the present case, the injury sustained by the Claimant means that I have no direct evidence from the Claimant as to whether she would or would not have been persuaded to proceed without the femoral vessels being exposed and prepared. There is clearly a real difficulty in relying on statements made with the benefit of hindsight in a case of this nature. However, I do place some weight on Mr Mohamed’s evidence that the Claimant was “quite shocked” by the risk of mortality that he quoted (albeit of 20%) and that she “specifically asked about this”. I also accept the evidence of the Claimant’s husband (see [178] above) that the Claimant “would have wanted to take reasonable steps to see what could be done to minimise the risks of surgery”.

Had the risks inherent in the proximity of her enlarged aorta to the sternum been fully explained to the Claimant and had the option of exposing the femoral vessels to reduce the risks consequential upon injury to the aorta been explained to her then, it seems more likely than not that the Claimant would have opted for the variant which improved her chances of survival and mitigated the risks of more serious brain damage in the event of aortic injury – at least in the absence of compelling reasons not to do so. Whilst there were some “cons” involved in exposing the femoral vessels (see [88] above), they were limited and, in any event, the surgeons agreed that the femoral vessels should have been exposed if the risk of aortic injury was medium to high. In my judgment, it is therefore likely, on the balance of probabilities, that had the Claimant been properly informed as to this option then she would have opted to proceed with the sternotomy provided that the femoral vessels were first exposed and prepared. There is no evidence before me to suggest that Mr Nassar would have refused to take this preliminary step had the Claimant requested it.

As to the timing of the consent process, I accept the force of the Defendant’s submission that the consenting process in this case must be seen in the relevant context of a patient with serious congenital heart issues and under the care of a consultant cardiologist and who has received ongoing support and advice on her congenital conditions and appropriate treatment.

Nevertheless, even taking into account the Claimant’s long history of receiving consultant care for her congenital heart issues, the complexity and seriousness of the proposed surgery was such that the Claimant should have been booked in for an outpatient appointment to see the operating surgeon in advance of the day on which the surgery was scheduled. This is what the clinical notes for the 20 January 2022 pre-operative assessment indicate would happen given that Mr Nassar was not available on that day to see the Claimant and it is what should have happened. In my view, this goes beyond what should have happened “in an ideal world” (the words used in the joint statement of the experts).

In my judgment Mr Yap was correct when he stated in his report that in this case, a third re-do sternotomy, with a medium to high risk of aortic injury given the proximity of the aorta to the sternum, it was unacceptable practice for the surgeon to see the patient for the first time on the day of the intended surgery in order to explain the risks of the operation for the purposes of seeking to obtain informed consent. This opinion evidence is also consistent with the RCS’s guidance, quoted at [62.b] above, to the effect that the process of consent should begin well in advance of treatment, that the patient should be able to take away a copy of the signed consent from for reference and reflection, and that a letter should be sent to the GP giving an account of the discussion that has taken place. In my view a good reason would be required to explain and justify a failure to see a patient in the position of the Claimant as an outpatient in advance of surgery.

Mr Nassar’s explanation as to why no appointment was arranged for the Claimant to see him as an outpatient well in advance of the surgery was unsatisfactory. He said “I assume we tried”, but he was unsure as to what, if any, steps were taken in this regard. His evidence was that his clinic would usually be on a Wednesday, but might be cancelled if there were emergencies. He suggested that patients were often contacted at short notice when spaces emerged in his schedule and he did not appear to consider that it was part of his responsibility to identify which patients should attend his clinic. I was left with the impression that there were no clear systems in place to (a) identify which patients should be seen as a matter of priority and (b) to ensure that these patients were contacted. This might be an incorrect impression, but, if so, then it is unfortunate that Mr Nassar was not able to explain the system pertaining to his clinic more satisfactorily. I have seen no documentary evidence of any effort being made on the part of the Defendant to contact the Claimant to arrange an appointment following 20 January 2022. I agree with Mr Yap’s characterisation of the consenting process in this case as “chaotic”.

In the absence of a good reason to explain and justify the failure to see the Claimant in advance of the day of surgery, the Defendant fell below the requisite standard of care in failing to ensure that the Claimant was contacted for an outpatient appointment to see Mr Nassar in advance of the day of the surgery.

When Mr Nassar did eventually see the Claimant, on the morning of the surgery of 3 May 2022, the contemporaneous evidence, set out at [183] above, suggests that he may have spent only three minutes with the Claimant during the ward round to explain the benefits and risks of the surgery and obtain her signature on the consent form. If this is correct, then it seems a very short period of time to devote to the consenting process, even taking into account the fact that this followed on from the previous consenting process with Mr Mohamed in April.

In any event, it is apparent from the Claimant’s WhatsApp messages to her mother on 24 April 2022 and on the morning of 3 May 2022 (see [65] above) that she was exceedingly keen for the surgery to proceed without further delay. The Claimant had attended accident and emergency on 17 April because of her worsening symptoms and her surgery had been expedited on this basis. As set out at [208] above, on the balance of probabilities, the Claimant would, in my judgment, have consented to the procedure on the basis that the femoral vessels were exposed and I have no reason to believe that Mr Nassar would have refused to proceed on that basis. In the circumstances, I do not consider that it is likely that there would have been any need for a second opinion nor, in any event, do I find that the Claimant would have elected to postpone the surgery on 3 May 2022.

In the circumstances, it is not necessary to engage with the further questions as to who, where and when any second opinion would have likely been provided as such issues do not arise. In case I am wrong on my conclusions, it is evident that there were other tertiary referral centres to which the Claimant could have been referred (including Mr Yap’s MDT at Barts, see [194] above) and Dr Jansen is clear that she would have endeavoured to refer the Claimant for a second opinion had she asked. Had the Claimant obtained a second opinion then it seems likely that the advice as to the risks of mortality would have been the same, namely 5-10%. If the evidence of Mr Yap and Mr Roberts is correct then, on the balance of probabilities, another surgeon would not, in fact, have advised the Claimant of the existence of the option to expose and prepare the femoral vessels as a means of mitigating the consequences of aortic injury. However, as set out above, in my judgment, such advice should have been given in accordance with the principles set out in Montgomery.

In light of the agreement between counsel that the determination of the preliminary issues should be narrowly confined to findings of fact and should not deal with the legal issues of causation which arise in relation to the Claimant’s reliance on Chester v Afshar, I make no comment on the application of the legal principles set out in that case.