SIR publishes new training guidelines for endovascular thrombectomy


guidelinesThe Society of Interventional Radiology (SIR) has today published new training guidelines for endovascular stroke treatment in the Journal of Interventional Radiology (JVIR). This is the first update since 2009, when the society released training guidelines for intra-arterial catheter-directed treatment of acute ischaemic stroke.

“Obviously, the world of stroke intervention has changed tremendously since then”, lead author of the guidelines David Sacks (The Reading Hospital and Medical Center, West Reading, USA) tells Interventional News. At the time, catheter-directed thrombolysis was the only such therapy studied in randomised trials. In the intervening decade, mounting positive evidence for endovascular thrombectomy from randomised trials and meta-analyses, and the subsequent growth in the number of these procedures being performed each year, has led the SIR to believe that these new recommendations are timely and necessary.

The guidelines were authored by a diverse group of interventional radiologists, specifically-trained neurointerventionalists, endovascular specialists, and stroke neurologists, as well as academics and community hospital staff; they varied to being freshly out of training themselves, to having over 30 years’ experience of stroke interventions. Sacks explains to this newspaper: “We solicited people from a range of backgrounds so that we could have a diversity of opinion, experience and knowledge. We wanted to make sure that we were meeting the needs of people in many different environments, as well as meeting the needs of patients.”

However, no official representative of the Society of NeuroInterventional Surgery (SNIS) participated in the creation of these guidelines. Despite the SIR inviting various leaders and former leaders of SNIS to participate in the creation of these guidelines, “for various reasons those individuals declined”, Sacks reports. Several of the guidelines authors are members of SNIS, though. Sacks also adds, “We [SIR and the guidelines authors] have maintained lines of communication with the current leaders of SNIS, and we remain open to working with them in whatever ways would advance patient care for stroke interventions”.

“Interventional radiologists are seeking guidance as to how they should train”

Earlier this year, SIR, the Cardiovascular and Interventional Radiology Society of Europe (CIRSE), and the Interventional Radiology Society of Australasia published a joint position statement in the Journal of Vascular and Interventional Radiology (JVIR) outlining the role of interventional radiologists in acute ischaemic stroke interventions. Sacks, who was also the lead author of this joint statement, describes this as “an acknowledgement that interventional radiologists have an important role to play in stroke care”, but adds that “it was also cautionary, stating that interventional radiologists must be adequately trained”. These latest guidelines provide the training pathway alluded to in the earlier joint statement.

Sacks says that the new guidelines “make clearer what training and experience interventional radiologists are expected to have to be performing these [endovascular stroke] procedures”. He continues: “I think there are an increasing number of interventional radiologists already who are involved in stroke interventions, and like any kind of medical care, there will be a range of experiences and capabilities. We are trying to bring more uniformity at a high level of what that training and experience should be. I think there are already many hospitals that are turning to their interventional radiologists to help provide this care, and those interventional radiologists are seeking guidance as to how they should train. They want to do a good job, and they need to know what the recommendations are for them to train to be able to do the good job they are committed to.”

Specific training requirements

The updated guidelines state: “The IR physician is expected to have baseline mastery in accordance with the Accreditation Council for Graduate Medical Education (ACGME) milestones of level 4 or higher of arterial access, selective vascular catheterisation, including microcatheters, and mechanical revascularisation, including thrombectomy and thrombolysis of extracranial vessels.  The IR physician is also expected, as part of core training and certification in diagnostic radiology, to have experience with neuroimaging including CT, MRI, and perfusion imaging.”

There is no requirement for full-scope neuroendovascular training through either a formal neurointerventional fellowship or near equivalent. “However”, the authors note, “specific and rigorous training with demonstration of competence is required”. Adequate training, according to Sacks et al, involves the following:

  1. Formal training that imparts the required depth of cognitive knowledge of the brain and its associated pathophysiological vascular processes, clinical syndromes, the full array of ischemic stroke presentations, and pre-, peri-, and post-procedural care.
  2. Procedural skill, including management of complications secondary to endovascular procedures, that is achieved by supervised training by a qualified instructor.
  3. Diagnostic and therapeutic acumen, including the ability to recognise procedural/angiographic complications. This is achieved by studying, performing and correctly assessing an adequate number of diagnostic and interventional/endovascular procedures with proper tutelage.

In addition, the new SIR guidelines stipulate that “a minimum of six months of documented cognitive neuroscience training during or post-residency is necessary to become competent in the interventional care of patients with acute ischaemic stroke”.

Three training pathways are outlined in the document to highlight how this competency could be achieved. Firstly, the new ACGME accredited IR/diagnostic radiology residency programme in the USA will provide trainees with at least two years of dedicated clinical and procedural training, with “motivated residents” able to access up to six months of neuroscience training. Alternatively, practicing interventional radiologists could achieve competency to treat ischaemic stroke through a proctorship. The guidelines authors elaborate: “Ideally, supervised training would include robust, hands-on training, not limited to interventional techniques but also workup prior to and management after thrombectomy”. The final training pathway detailed in the guidelines is for physicians to enrol in an educational stroke course involving procedural simulations and potentially virtual reality to supplement stroke training.

The consensus of the guidelines’ authors is that a minimum of 10 procedures per year for each operator is recommended for maintenance of physician competence. The onus also falls on institutions to provide appropriate infrastructure and support, according to Sacks and colleagues. They conclude: “Institutions performing stroke intervention must establish quality assurance programmes to optimise processes and outcomes, and both technical and clinical outcomes must be entered into a database or registry”.

Endovascular thrombectomy procedures on the rise

“I think the number of stroke interventions will continue to increase”, Sacks predicts. The current number of stroke interventions are vastly fewer than the number of patients generally acknowledged to be eligible. A 2018 survey from the European Stroke Organisation (ESO), the European Society of Minimally Invasive Neurological Therapy (ESMINT), the European Academy of Neurology (EAN) and the Stroke Alliance for Europe (SAFE) investigated the access to and delivery rates of stroke care in 44 European countries—and found that over 65,000 stroke patients eligible for endovascular treatment were not provided with this intervention. On average, 1.9% (95% confidence interval [CI], 1.3–2.5) of all patients with an ischaemic stroke in Europe received endovascular treatment, while a recent UK study estimated that approximately 10% of stroke patients are good candidates.

The most common reason that stroke intervention was not performed on an eligible patient was the lack of adequately trained physicians, leading Sacks to argue that there is a need for well-trained interventional radiologists to perform these procedures. “Having more interventional radiologists who are adequately trained will allow more patients in total to be treated when it is appropriate to treat them”, he says.

In addition to the potential increase in stroke interventions caused by treating a greater majority of eligible patients, Sacks also believes the overall number of eligible patients will rise. “The estimates on which these articles are relying [for estimates of eligible patients] are based on the well-accepted indications: patients within six hours, patients with ICA-M1/M2 occlusions, and patients whose strokes are sufficiently severe but do not have large core [infarcts]”, he says. “There are multiple trials underway looking at whether patients with mild strokes or patients with large core [infarcts] will benefit.

“I think that in the future, we are going to be treating increasing numbers of patients with a broader set of indications. Stroke patients will be treated at an increasing number of centres [in the USA] rather than [just at] the current number of thrombectomy-capable stroke centres. I think there will be more uniformity in the way people are training, and more uniformity in the expectations for outcomes.”


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