Irfan v Western Sydney Local Health District

Background

1. Professor Brew and Professor Yan are both trained neurologists: they are within the same field of specialty. However, unlike Professor Brew, Professor Yan has particular expertise in clot retrieval. That distinction is at the heart of the present application.
2. In response to a series of questions, Professor Brew's 25 July 2024 report provided the following answers: "2. Could you please provide a short overview of your current appointment/s as a Consultant Neurologist, particularly in relation to your historical and current clinical experience as an On-Call neurologist in: (a) The management of patients with acute strokes or suspected strokes generally? (b) The management of patients who are candidates for thrombolysis or clot retrieval? I have been a senior staff specialist at St Vincent's Hospital since 1989, working in both the Neurology and Immunology Departments. I have been on call for acute neurology approximately every 5 weeks for 24 hours and every 6 weeks for 72 hours. I established the Stroke Unit at St Vincent's Hospital and when I am on call for neurology this includes acute stroke calls, which require clinical assessment and consideration of thrombolysis and clot retrieval. The unit has 6 acute stroke beds with monitoring and sees approximately 30 to 40 patients per month, with approximately one quarter of those being eligible for thrombolysis. Clot retrieval is assessed and managed in approximately 2 patients, on average, per month. The Stroke Unit has regular morbidity and mortality meetings (approximately every 3 to 6 months) where all the cases of thrombolysis are discussed both for appropriateness and for potential issues in relation to delays in administration of thrombolysis. The same is true for patients who have clot retrieval. … 4. Could you please distinguish, as you see it, your role and expertise as a Consultant Neurologist, as against that of a Neuro-interventionist such as Professor Bernard Yan? My role is essentially more at the frontline (so to speak). I assess patients acutely who have presented with what appears to be acute stroke. I am involved with assessment of the history and examination and interpretation of the results of investigations, including the appropriateness for treatment with what is known as hyperacute stroke therapy, namely thrombolysis and/or clot retrieval. My understanding of Professor Bernard Yan's role is that relating more to the procedural aspects of clot retrieval and the interpretation of imaging for the appropriateness of clot retrieval. I am sure that Professor Yan is involved (although to a lesser extent) in the clinical aspects of the assessment, as this is primarily the role of the referring neurologist. For the clarification of the Court, when a patient presents with potential acute stroke they are triaged Category 2 after the ambulance staff (usually) have alerted the emergency staff of an incoming patient requiring urgent assessment. Once the patient has been quickly triaged, a stroke code is issued. Apart from emergency department staff in attending the patient, a stroke registrar is called. He or she then assesses the patient and discusses it with the neurologist on call, who then frequently goes to the hospital to assess the patient himself or herself. All this is happening whilst the patient is either having (or just had) imaging to assess whether thrombolysis should or should not be given and whether clot retrieval is a possibility. The decision to consider thrombolysis is made by the neurologist on call. The decision for clot retrieval is also made by the neurologist on call but with a subtle difference. The neurologist on call will potentially consider a patient as being appropriate for clot retrieval and then the case is discussed with the neurointerventionist who is on call. As I understand it, Professor Yan's position is one of neurointerventionist. There is then a discussion between the neurologist on call and the neurointerventionist as to the best way to proceed. Sometimes the neurologist on call is keen for the patient to have clot retrieval but the neurointerventionist considers it to be inappropriate. As such, clot retrieval is not performed. In other circumstances the neurologist on call, after discussion with the neurointerventionist, is not supportive of clot retrieval, even though the neurointerventionist may be. In such a circumstance, it is the neurologist on call who has the final decision making capacity."
3. Since Mr Irfan's earlier application, the first defendant has completed service of evidentiary statements, including the statement of Dr Andrew Martin, dated 20 October 2023. A relevant summary for present purposes of what happened on the day in question, taken from Dr Martin's statement, is as follows.
4. Dr Martin was employed as a Staff Specialist Neurologist at Blacktown Hospital at the time of the subject incident in May 2020. On Sundays, Blacktown Hospital is staffed by a 24 hour on-call consultant neurologist but there are no neurology staff on-site. On 17 May 2020, Dr Martin was the on-call neurologist for the hospital.
5. At around 16.50 hours, he was contacted by the Emergency Department in relation to Mr Irfan. He reviewed Mr Irfan's CT brain scan and CT angiogram remotely from home. Dr Martin says that without the CT brain scan and CT angiogram "I could not make a diagnosis or treatment plan". At around 17.00 hours he called the Liverpool Network Hotline for clot retrievals and was put through to Dr Jason Wenderoth. Dr Martin describes Dr Wenderoth as an "interventionalist" [sic] at Liverpool Hospital.
6. After reviewing the imaging, Dr Wenderoth told Dr Martin that he (Dr Wenderoth) had accepted Mr Irfan for clot retrieval at Liverpool Hospital and gave Dr Martin instructions in relation to his transfer. They also discussed whether Mr Irfan would derive benefit from thrombolysis. The clinical records reveal that the clot retrieval procedure was performed by interventionists at about 21.41 hours.
7. Mr Irfan maintained that the following propositions emerge from this evidence of Dr Martin: 1. After doctors in the Emergency Department had ordered a CTB and CTA, Dr Martin's role as the on-call neurologist included making a diagnosis/differential diagnosis (if possible) and treatment plan. 2. Once Dr Martin had considered the potential for a clot retrieval, the protocol appears to have been that he made contact via the Liverpool Network Hotline for clot retrievals, and via that hotline, came into contact with an interventionist, in this case Dr Jason Wenderoth. 3. Dr Martin sought input from Dr Wenderoth regarding how to proceed. 4. Dr Wenderoth reviewed the imaging before making a decision on whether or not to accept Mr Irfan for clot retrieval. 5. The decision to include clot retrieval was informed by Dr Wenderoth's review and interpretation of the imaging and consideration of the case. 6. The ultimate decision on whether to perform clot retrieval sat with Dr Wenderoth, the interventionist, not Dr Martin, the on-call neurologist. 7. Clot retrievals are performed by interventionists, not on-call neurologists.
8. Mr Irfan submitted that Dr Martin's evidence is largely consistent with Professor Brew in relation to the distinction between the clinical practice and experience of an on-call neurologist as opposed to that of an interventionist. According to Professor Brew: 1. his role as a current practising on-call neurologist at St Vincent's Hospital includes being involved in clinical assessment of patients suffering an acute stroke or suspected stroke, and consideration of the appropriateness of thrombolysis. 2. the neurologist will potentially consider clot retrieval but then discuss the case with the neuro-interventionist who is on call, a clinician such as Professor Yan. 3. although they will discuss the best way to proceed, if the neuro-interventionist considers it to be inappropriate, clot retrieval will not be performed.
9. The potential significance of the present dispute is also highlighted by Mr Irfan's particulars of negligence which include the following: (l) Failing to carry out clot retrieval in a timely manner. 1. Failing to recognise the first plaintiff's neuroimaging showed large vessel occlusion warranting endovascular thrombectomy. 2. Failing to appreciate the first plaintiff's age and clinical picture warranted urgent transfer for endovascular thrombectomy. 3. Failing to organise urgent transfer to Liverpool Hospital where endovascular thrombectomy was available. 4. Failing to consult Mr Irfan about the urgent need to transfer the first plaintiff for thrombectomy.
10. The defendants deny all particulars of negligence, including (l).
11. Professor Yan is described on his website as a dual-trained neurologist and endovascular neuro-interventionist, a subspecialty which treats acute stroke, aneurisms and arterio-venous malformation.
12. In his report, Professor Yan answers a series of questions concerning "thrombectomy" in addressing aspects of breach and causation including: 1. what an endovascular thrombectomy (i.e. "clot retrieval") comprises, the benefits it carries, and its availability in Australian hospitals (supported by a survey of the literature); 2. whether vertebral artery dissection precluded thrombectomy in Mr Irfan's case; 3. what would have likely been revealed on imaging performed about 1 hour and 10 minutes to 1 hour and 40 minutes earlier than it was in fact performed; and 4. the likely outcome following earlier thrombectomy performed on 17 May.

Consideration

1. The defendants perceive that Mr Irfan's desire to ensure that he is entitled to rely upon Professor Yan is inspired by the existence of differences between Professor Brooder's 2 March 2023 report and his 31 March 2023 report. Professor Brooder is another neurosurgical expert qualified by Mr Irfan. The defendants point to the following portion of Dr Brooder's earlier report said to support that perception: "Clot Retrieval 19. Had Mr Irfan undergone brain CT by 14:30, or even 15:00, to exclude haemorrhage would you expect his neurological team to have considered clot retrieval as an alternative treatment to thrombolysis? The treatment consensus concerning the use of endovascular clot retrieval is that intravenous thrombolysis remains first-line therapy and that thrombolysis should be initiated for any eligible patients without delay even if the possibility of treatment by endovascular clot retrieval is being considered. Given the established treatment consensus concerning consideration of clot retrieval in the management of ischaemic stroke, even if Mr Irfan had undergone a brain CT by 14:30 hour (or even by 15:00 hour) to exclude haemorrhage, I would not expect that his neurological treatment would have considered clot retrieval as an alternative treatment to thrombolysis. 20. If so, would you expect his neurological team to contact Liverpool Hospital immediately for a consultation as to timing and arrangements for potential transfer for clot retrieval (even if thrombolysis was attempted in the meantime)? Not applicable." [Emphasis added]
2. That has to be compared with what Dr Brooder said in his 31 March 2023 report as follows: "22. During that period of time, would you expect a treating team (exercising reasonable skill and care) to take steps to prepare Mr Irfan for transfer to another hospital for 'clot retrieval' (endovascular thrombectomy) in case the thrombolysis turned out to be unsuccessful? If so, what would these steps have involved? During that period of time and considering Mr Irfan's relatively young age and his extremely critical clinical condition, then I would expect a treating team (exercising reasonable skill and care) to take urgent steps to prepare him for transfer to another hospital for 'clot retrieval' (endovascular thrombectomy) in case the thrombolysis turned out to be unsuccessful. The steps to effect Mr Irfan's transfer to another hospital for endovascular thrombectomy would have been to initially establish the nearest hospital capable of undertaking endovascular thrombectomy and then liaising directly with both that hospital's stroke team and the hospital's neurointerventionalist [sic]. At the same time arrangements would have been made for an urgent ambulance transfer as a time-critical inter-hospital transport. 23. Mr Irfan ultimately underwent clot retrieval at Liverpool Hospital at about 20:55 on 17 May 2020. If he had undergone this procedure 2-3 hours earlier, would he more likely than not have achieved a better outcome? Please provide the reasons for your answer. I would consider that, if Mr Irfan had undergone endovascular clot retrieval 2-3 hours earlier, then he would have been more likely than not to have achieved a better outcome. Studies have shown that endovascular clot retrieval undertaken within six hours of stroke results in a 20% absolute reduction in death and disability. Residual disability following a stroke is directly proportional to the amount of ischaemic damage that occurs within the affected brain tissue. The extent of ischaemic damage is related to the reduction in blood flow through the affected brain tissue and increasing the blood flow to the region potentially results in a corresponding reduction in the degree of ischaemic damage. Increasing the blood flow within Mr Irfan's basilar artery by endovascular clot retrieval would potentially have resulted in a reduction in the extent of ischaemic damage within his brainstem that would have then achieved a better clinical outcome."
3. The defendants wish to maintain that Dr Brooder's earlier opinion, that Mr Irfan's neurological treatment would not have included consideration of clot retrieval as an alternative treatment to thrombolysis, effectively forecloses any argument about that issue, even notwithstanding that on one view his later opinion is to the contrary. For reasons that are numerically understandable, the defendants did not, and do not, oppose Mr Irfan relying upon the opinion of both Professor Brew, a professor of neurology, whose 25 July 2024 opinion is extracted earlier in these reasons, or upon Dr Brooder. Professor Brew's specialty is the same as that of Dr Brooder.
4. Professor Brew has referred to the "subtle difference" in roles between a neurologist on-call and a neurointerventionist. It should be noted that, for obvious reasons, I did not have Professor Brew's report when deciding a similar dispute in 2023. However, Professor Brew expands upon his reference to the subtle difference in roles, and appears clearly to endorse the existence of Professor Yan's specialty as a neurointerventionist as what might be called a subspecialty.
5. Professor Yan's 22 March 2023 report was served on the first defendant on 28 March 2023. Dr Brooder's reports dated 2 March 2023 and 31 March 2023 were served on the first defendant later on 3 April 2023. Professor Brew's 25 July 2024 report could not have been served before that time. Unless I misunderstand the position, therefore, Professor Yan was the first specialist in the neurological field served upon the first defendant and yet the first defendant objects to it and not Professor Brew's report served somewhat later.
6. It is instructive in those circumstances to consider the defendants' written submissions at paragraph 26 and 27: "26. In Guerin v Hillier; Netherwood v Hillier; Moore v Pell [2020] NSWSC 1322 Fagan J considered the applicable principles relating to multiplicity of experts in a medical negligence matter. In noting that the Court had a discretion pursuant to s. 62(3)(b) of the CPA and UCPR r 31.20(2)(e) to limit the number of witnesses including experts that a party may call to give evidence, and in ordering the plaintiffs to limit the number of experts to be relied upon in their case, his Honour explained the rationale behind the discretionary powers of the Court as follows at [7]: '[7] The clear purpose of s 62(3)(b), r 31.20(2)(e) and the Practice Note is to enable the Court to achieve efficiency and economy, for itself and for the parties, in cases where expert opinion evidence is to be adduced. When a plaintiff serves reports of multiple experts who all express substantially the same opinions, as occurred here, the time required for the defendant's experts to respond is increased; the defendant's experts reports necessarily have to be longer and more expensive ; delay is incurred in finding a suitable date for a larger than necessary number of professionals to participate in a conclave; the duration of the conclave is extended and the length of its report is unnecessarily increased; greater expense is incurred in securing the attendance of all of the professional experts at trial and, of course, finding a suitable day within the hearing for all of them to attend and give concurrent evidence is made more difficult.' 27. As before, those concerns continue to apply here: if evidence from Prof Yan report is allowed, the defendants face Hobson's choice: either suffer Krause and Simon being outnumbered in the joint conference, or incur the time and expense of garnering expert evidence from an additional subspecialty in reply to Yan. They should not be put to that choice by the plaintiffs' mismanagement of their case." [Emphasis added]
7. The defendants' concerns about disruption, expense and delay referred to in those submissions have to be compared with what emerged in an exchange between Mr Cheney SC and me in the course of the application: "HIS HONOUR: Let me ask you this. I'm not sure what's your procedural position in terms of prejudice. I haven't a view about it yet, as I never do. If Prof Yan were entitled to give evidence, if the report that the plaintiff wants to rely upon is admitted into evidence, would the defendant then want to call a neurointerventionalist to meet that report or would it be content to rely upon the reports from those neurologists, or whoever you have, that are already in evidence? CHENEY: I suspect, but I don't know, your Honour, but I suspect the latter. We might be able to deal with it by asking our existing experts to respond, but I don't know. Because Prof Yan's report has not been in play before this application. HIS HONOUR: It's not been? CHENEY: Has not been. No leave to rely upon has been given before this application. We have not asked our experts to respond to Prof Yan. It was supplied to Prof Simon, by the second defendant's previous solicitors, but he expressly defers about responding to it. He does respond to Dr Brooder, but he doesn't say anything about Prof Yan's. HIS HONOUR: The reason I say it, more than one expert in a single expertise issue is not limited to this, but questions about whether or not a further report from an additional expert would send an opposing party off to chase another expert, expend more money, incur more delay and the like, is an issue that informs the question. CHENEY: Yes. HIS HONOUR: So that is the reason I ask. CHENEY: I suspect that the position ultimately will be that we are instructed to commission a counterpart to Prof Yan to say there is complete parity of practice experience. For all I know, it may be that our existing neurologists do say that they can't respond to all aspects of Yan because of that fine distinction in practices: Clinical neurologists versus the practice proceduralist. But I am not in a position to say, your Honour."
8. In my view, the spectre of the defendants having to incur the time and expense of garnering expert evidence from an additional subspecialty seems more apparent than real. It does not appear to me to be a matter of much significance in this case. The issue of procedural or other prejudice is of course not decisive but these decisions are discretionary and the defendants have raised the issues of expense and delay.
9. Practice Note SC CL 7 is instructive: "31. The Court is concerned about the number of experts often expected to give evidence in personal injury cases. The practice of having a large number of experts qualified, both medical and otherwise, whose opinions may be overlapping and whose reports either are not used or are of little assistance to the court is costly, time-consuming and productive of delay. … 33. The Court recognises that the liability aspects of medical negligence claims often involve complex issues as to breach and causation. This may require more than one expert from a party to give evidence on a particular issue or issues…"
10. In my opinion, this is such a case. The defendants will undoubtedly contend that Dr Brooder has expressed inconsistent opinions. Professor Yan may be better placed to give an objective opinion about that criticism than Dr Brooder. Professor Brew's recognition of the subtleties would also tend to support Mr Irfan's assertion that Professor Yan brings a unique perspective to the neurological landscape.
11. Doing the best I can I consider that the principled considerations that support the restriction upon multiple experts should yield in this case to Mr Irfan's concern to explore the comparison between the clinical indications for thrombolysis and clot retrieval. I will make orders 1A and 1B of the amended notice of motion filed on 18 November 2024.

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