Summary
The Claimant brought a claim of clinical negligence after suffering a rare but serious complication (anal stenosis) of an operation performed by the Defendant to surgically remove her haemorrhoids. The judge found that the evidence of the Claimant’s expert was based on limited experience or expertise. There were also several instances where he had not acted in accordance with his duties as an expert.
Learning points
Leaning points for experts
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Expert witnesses are under a duty to assess the arguments of both sides and weigh them up fairly. It may damage or even be fatal to your evidence if you do not engage with the arguments of the opposing side.
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You risk losing credibility if you refuse to admit when you have changed your opinion or make reasonable concessions when you have been shown to have been wrong.
Learning points for instructing parties
The case
The Claimant brought a claim of clinical negligence after suffering a rare but serious complication (anal stenosis) of an operation performed by the Defendant to surgically remove her haemorrhoids. The original allegations of negligence in respect of the conduct of the surgery were discontinued after the joint statement, but the Claimant continued to the allege that the Defendant acting negligently in: (i) grading her haemorrhoids, (ii) failing to discuss non-surgical options, and (iii) failing to adequately explain the risk and benefits of the surgery (a ligature haemorrhoidectomy).
Haemorrhoids are graded in severity from Grade 1, small swellings on the inside lining of the anus, to Grade 4, haemorrhoids which permanently hang down from within the anus and cannot be pushed back inside.
The expert evidence
Mr T provided expert evidence for the Claimant and Professor P for the Defendant. Both experts retired from clinical practice prior to the date of the surgery. Counsel for the Claimant conceded that Mr T’s level of expertise in terms of the live issues in this case was limited given how few haemorrhoidectomies he had ever carried out, and how few patients he had seen with grade 3 or 4 haemorrhoids.
The evidence of Mr T
Mr T is a retired general and colorectal surgeon with over 25 years’ experience in a District General Hospital. In cross-examination, he said that by the 1990’s he was working almost exclusively as a colorectal surgeon, mainly cancer but also haemorrhoids. However, he said he had not done many haemorrhoidectomies and had never done a ligature haemorrhoidectomy. From 2009 he was doing very little operating on haemorrhoids and none after 2010. He agreed that it was "a reasonable point" that it was difficult for him to identify the standard of a reasonably competent haemorrhoid surgeon in 2019.
The judge reached the conclusion that Mr T’s evidence was based on limited experience or expertise.
During cross-examination, it emerged that in several instances he had not acted in accordance with his duties as an expert under CPR Part 35 and the Practice Direction to Part 35. These included:
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Referring in his witness statement dated 21 July 2021 to his having read the Claimant’s and Defendant’s witness evidence when this was only served in April 2024.
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Although he accepted that he was under a duty to assess the arguments of both sides and weigh them up fairly, neither his expert report, nor his subsequent report, made any reference to the Defendant’s case and he had not analysed the Defendant’s case.
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Asserting, without any evidence to support it, that the Defendant had graded the haemorrhoids based on their size alone, rather than by using the Grade 1-4 grading system which was consistent with the practice of a responsible body of Consultant Colorectal Surgeons.
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Denying that he had changed his opinion despite stating in his first report that in his opinion the Claimant’s haemorrhoids were Grade 1 and in the Joint Statement that it was likely that the Claimant had Grade 1-2 piles.
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It was also clear in his report that he wrongly thought the fissure was not healed and therefore needing treating before changing his opinion in the Joint Statement which noted that “as the fissure is healed it needed no active treatment at that time”. Despite this Mr T denied he had changed his opinion. The judge found it concerning that Mr T was unable to make this reasonable concession and admit that he was wrong.
The evidence of Professor P
Until his retirement Professor P was a full-time colorectal surgeon at the National Bowel Hospital where he undertook a combination of complex and anorectal work. He also ran several clinical trials relating to haemorrhoids in which he did all the surgery. He was made an Honorary Professor of Colorectal Surgery by Imperial College London in 2000. He is the author of 9 recent textbooks in colorectal surgery and has contributed to 300 original articles and 59 book chapters. The Joint Statement listed twelve publications by Professor P on haemorrhoids, including diagnosis and treatment, haemorrhoidectomy and evidence-based practice.
The judge noted that “[Professor P] has extensive experience of diagnosing, grading and treating haemorrhoids and of undertaking haemorrhoidectomies. I found him to be a forthright, straightforward witness who gave direct answers to questions and made concessions where appropriate (as set out in the body of this judgment below). In my judgment his evidence is reliable, objective and unbiased and I therefore consider it appropriate to place considerable reliance on it. I prefer his evidence in all respects to the evidence of Mr T save where he and Mr T agree.”