Quality over quantity: Consensus document outlines training guidelines for ischaemic stroke intervention


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Twelve international societies have joined together to produce a consensus document to guide physicians seeking to treat acute ischaemic stroke patients with mechanical thrombectomy as to the required training and qualifications.

This consensus document comes after the results of five randomised controlled trials have changed the face of acute ischaemic stroke treatment, providing overwhelming evidence in favour of mechanical thrombectomy for patients with emergent large vessel occlusions. It comes partly in response to suggestions that physicians without prior experience or formal neuroendovascular training should consider attempting treatment to address some of the geographical limitations to rapid access to acute stroke centres providing mechanical thrombectomy. The multi-society consensus states however, “We believe that a neuroscience background, dedicated neurointerventional training, and stringent peer-review and quality assurance processes are critical to ensuring the best possible patient outcomes. Well-trained neurointerventionalists are a critical component of an organised and efficient team needed to deliver clinically effective mechanical thrombectomy for acute ischaemic stroke patients”.

The new training guidelines were released simultaneously in eight journals including: Interventional Neuroradiology, American Journal of Neuroradiology, Interventional Neurology Journal, European Journal of Minimally Invasive Neurological Therapy, Journal of Neuroendovascular Therapy, Journal of NeuroInterventional Surgery, Neuroradiology, and Neurosurgery.

The document maintains that “it is important to recognise that modern endovascular stroke therapy focuses on direct clot removal with mechanical devices, as compared with previous paradigms where intra-arterial thrombolytic infusion was an acceptable treatment option for large vessel occlusions. The technical skills needed to safely deliver devices into the intracranial circulation are significantly more involved than simply placing a catheter for medication infusion. Catheter skills from other circulations do not replace the need for formal training in safe intracranial microcatheter navigation and device placement.”

It has been established that both patient selection and procedural expertise are critical in achieving a good clinical outcome. Hence, the authors have found a clear rationale for formal training in both clinical neuroscience and interventional neuroradiology.

The purpose of this document, they write, “is to define what constitutes adequate training for physicians who can provide endovascular treatment for acute ischaemic stroke patients. These training guidelines are modelled after prior standards of training documents such as the training, competency and credentialing standards for diagnostic cerebral angiography, carotid stenting and cerebrovascular intervention and the performance and training standards for endovascular ischaemic stroke treatment, written and endorsed by multispecialty groups. In addition, the importance of organ specific training, rigorous quality improvement benchmarks, and minimum volume requirements needed to maintain high quality care has been extensively described for acute myocardial infarction, an analogous time sensitive disease”.

According to the authors, this document represents an international consensus on adequate training to safely and effectively perform these procedures. The guidelines are divided into three main areas: baseline training and qualifications; maintenance of physician qualifications; and hospital requirements.

While acknowledging that specific training pathways may differ across nations, the consensus document maintains that adequate training to perform emergent endovascular stroke intervention is mandated. According to the document, new practitioners who are not currently performing acute stroke intervention with mechanical thrombectomy must undergo:

  1. Residency training (in radiology, neurology or neurosurgery) which should include documented training in the diagnosis and management of acute stroke, the interpretation of cerebral arteriography and neuroimaging under the supervision of a board-certified neuroradiologist, neurologist or neurosurgeon with subsequent board eligibility or certification. The residency programme and supervising physicians should be accredited according to national standards as they pertain to the countries involved. Those physicians who did not have adequate such training during their residencies must spend an additional period (at least one year) training in clinical neurosciences and neuroimaging, focusing on the diagnosis and management of acute stroke, the interpretation of cerebral arteriography and neuroimaging prior to their fellowship in neuroendovascular interventions.
  2. Dedicated training in interventional neuroradiology (also termed endovascular neurosurgery or interventional neurology) under the direction of a neurointerventionalist at a high-volume centre. It is preferred that this is a dedicated time (minimum one year), which occurs after graduating from residency. A training programme accredited by a national accrediting body is also strongly preferred but not required. Within these programmes, specific training for intra-arterial therapy for acute ischaemic stroke should be performed, including obtaining appropriate access even in challenging anatomy, microcatheter navigation in the cerebral circulation, knowledge and training of the use of stroke specific devices and complication avoidance and management.

Further, the document urges practitioners to meet their national minimum procedural and training standards, adding that fellowships that are not accredited by national credentialing bodies should still have adequate training to meet their local minimum procedure requirements.

In terms of maintenance of physician qualifications, the consensus is that it is vital that the physician have ongoing stroke-specific continuing medical education. It suggests a minimum of 16 hours of stroke specific education every two years. Additionally, it reads, “the physician should participate in an ongoing quality assurance and improvement programme. The goals of this quality assurance programme for stroke therapy would be to monitor outcomes both in the periprocedural period and at 90 days. The quality assurance programme must review all emergency interventional stroke therapy patients”. In terms of threshold levels for recanalisation, complication rates, etc. the document suggests the following as a minimum: successful recanalisation (modified TICI 2b or 3) in at least 60% of cases; embolisation to new territory of less than 15%; and symptomatic intracranial haemorrhage rate less than 10%.

Finally, the consensus document outlines requirements for hospitals providing mechanical thrombectomy as treatment for acute ischaemic stroke, indicating that a centre must have 24/7 access to: “angiography suites suitably equipped to handle these patients, as well as equipment and capability to handle the complications; dedicated stroke and intensive care units, staffed by physicians with specific training in those fields; vascular neurology and neurocritical care experience; neurosurgery expertise, including vascular neurosurgery; and all relevant neuroimaging modalities, including 24/7 access to CT and MRI”.

The consensus document is the cumulative work of the following societies: American Academy  of Neurological Surgeons/Congress of Neurological Surgeons (AANS/CNS); American Society of Neuroradiology (ASNR); Asian Australasian Federation of Interventional Therapeutic Neuroradiology (AAFITN); Australian and New Zealand Society of Neuroradiology—Conjoint Committee for Recognition of Training in Interventional Neuroradiology (CCINR) representing the RANZCR (ANZSNR), ANZAN and NSA; Canadian Interventional Neuro Group (CING); European Society of Neuroradiology (ESNR); European Society of Minimally Invasive Neurological Therapy (ESMINT); Japanese Society for Neuroendovascular Therapy (JSNET); Sociedad Ibero Latino Americana de Neuroradiologica (SILAN); Society of NeuroInterventional Surgery (SNIS); Society of Vascular and Interventional Neurology (SVIN); and World Federation of Interventional and Therapeutic Neuroradiology (WFITN).

NeuroNews spoke to Istvan Szikora (National Institute of Clinical Neurosciences, Budapest, Hungary), Raul Nogueira (Emory School of Medince, Atlanta, USA) and Donald Frei (Radiology Imaging Associates, Denver, USA), the respective presidents of ESMINT, SVIN and SNIS, to find out what these societies are doing to help implement adequate training opportunities for physicians who would like to treat acute ischaemic stroke with mechanical thrombectomy.

Considering the concept of quality versus quantity, do you think that implementing these guidelines, thus initially limiting the number of practising physicians, will be better for the treatment approach (and patients) in the long run?

Istvan Szikora_main
Istvan Szikora (ESMINT)

Istvan Szikora:
The concept is not to limit the number of physicians but to make sure the treatment is done appropriately. Any neuroendovascular procedure requires thorough knowledge of cerebrovascular anatomy and pathology as well as skills and proper understanding of the devices and technologies applied. Acute stroke thrombectomy is an emergency procedure. Such knowledge and skills are of critical importance under emergency conditions. These skills cannot be provided without training and experience by maintaining sufficient case volume. Implementing the guidelines is primarily important not to harm patients but also not to ruin the excellent results of the method.

Raul Nogueira:
The idea is not to limit the number of practising physicians but to assure the proper quality of those delivering these highly complex treatments as we all know that in the wrong hands this therapy has higher chances of harming than helping patients.

Donald Frei:
The excellent results found in the recently published clinical trials were achieved because the physicians performing the procedures were fellowship trained neurointerventional surgeons practicing in conjunction with other physicians (stroke neurologists and neurointesivists) in high volume centres, offering comprehensive care of the stroke patient. These results cannot be duplicated by physicians with no training in neurointerventional surgery, who in effect, would be practicing or experimenting on patients. We have over 1,000 fellowship trained neurointerventional surgeons in the USA. That is more than enough qualified, experienced physicians to take care of our patients with acute ischaemic stroke secondary to ELVO.

What steps can be taken to ensure that as many patients as possible get access to mechanical thrombectomy in the current environment where the majority of qualified physicians are at a relatively small numbers of centres?

Istvan Szikora:
Centralisation of stroke care is needed. Patients with large vessel occlusion strokes need to be transferred and treated in comprehensive stroke centres. This requires proper organisation involving stroke centres, ambulance services and fast teleradiology/teleconsulting systems. To assist this work, ESMINT, together with ESO and ESNR will conduct a survey around Europe on the current situation of stroke care to help local organisations and governments. ESMINT is organising a European stroke registry collecting procedural and outcome data from as many European centres as possible.
Regarding human resources, I recommend ESMINT’s “Standards of practice in interventional stroke treatment” document published in September 2015 as follows: “The increased demand for a round-the-clock interventional service creates a significant challenge for most neurointerventional sites. ESMINT recommends that sites without sufficient number of trained neurointerventionists may employ dedicated specialists without full training in neurointerventions as supervised members of the neurointerventional team. Such individuals need to be trained to collect the necessary knowledge and experience level.”

Raul Nogueira_main
Raul Nogueira (SVIN)

Raul Nogueira:
I believe the main issue is not a number of physicians or stroke centres but rather their distribution. I think we must develop the concept of a certification of need for endovascular capable stroke centres where a catchment radius would be defined based on population density and ground/air medical transport access. This would avoid redundancy and volume dilutions in certain areas and promote the need for the development of new centres in currently underserved areas.

Donald Frei:
The concept of treating patients with ELVO only in a comprehensive stroke centre is not new. We have level 1 trauma centres that perform the same function for patients with severe trauma. Systems of care and EMS transport guidelines need to be developed and refined to get patients to a facility where comprehensive stroke care is available 24/7/365, including: rapid assessment by stroke neurologists, mechanical thrombectomy by stroke surgeons, and post procedure care in a neurointensive care unit by neurointensivists. These transport protocols will vary across the country depending on population density. What is needed in large cities will differ from what is needed in areas of lower population density. I practice in the western USA, where the population is dispersed across a wide area. In our region, we use air transport with helicopters and fixed wing aircraft to bring the patient from a five state area to our comprehensive stroke centre for treatment.

What plans does your society have in terms of training courses to help more physicians become qualified in treating acute stroke patients with mechanical thrombectomy?

Istvan Szikora:
Again, I refer to the above document: “ESMINT offers didactic education and certified exams through its ECMINT training course (http://www.esmint.eu/training-education/teaching-course). The practical training needs to be provided by the clinical site.”
Our ECMINT training course provides education in the entire neurointerventional field in four, four to five day courses in a two-year cycle. Treatment of acute ischaemic stroke represents a high priority among other neurointerventional topics.

Raul Nogueira:
We do not believe training courses are an acceptable solution. There is no replacement for dedicated neuroscience-based fellowship training in a high-volume centre given the complexity of what is involved. What we have done as a society is to promote the need for proper certification of fellowship training in order to assure that high-quality treatment will be available to our patients.

Donald Frei_main
Donald Frei (SNIS)

Donald Frei:
Neurointerventional surgery is a well-defined subspecialty with an accredited fellowship pathway to train physicians with expertise in the treatment of all neurovascular disease, which includes ELVO, brain aneurysms, arteriovenous malformations, etc. This multi-year fellowship training is available to any physician who has completed a residency in neuroradiology, neurosurgery or neurology. There is no weekend course or shortcut that would adequately prepare a physician to safely take care of these patients with the most dangerous form of stroke.