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Mechanical Thrombectomy

Mechanical Thrombectomy 

Download the Oxford AHSN Mechanical thrombectomy for acute ischaemic stroke: an implementation guide for the UK


Interventional Neuroradiology (INR) training for non-radiologists in the UK: current status (Feb 2019)


Training a non-radiologist to perform an INR procedure such as coiling a brain aneurysm, or mechanical thrombectomy (MT) for stroke is possible in the UK (a very small number of neurosurgeons from the UK and overseas have been trained to coil aneurysms in UK centres), but as yet there is no GMC approved INR training process for a non-radiologist. To date, supervision of INR training for non-radiologists has been undertaken ad hoc as a local process, complying with local NHS Trust governance procedures. Such informal ‘qualification’ may not be recognised by other institutions.


The Royal College of Radiologists (RCR) has assembled a multidisciplinary working group to prepare a credential ‘INR (Acute Stroke)’ that outlines the training required for a non-radiologist to perform aneurysm coiling and mechanical thrombectomy procedures. The GMC has supported credential development and the credential proposal is due to be submitted to the GMC later this year.


The current curriculum for INR training is contained within the sub-specialty training curriculum for IR.


The BSNR has also published training guidance for MT which broadly maps to multi-society international guidance for INR/MT training.


In the three years since meta analysis of modern trials showing clear evidence of the benefit of MT there has been a substantial expansion of radiology trainees subspecialising in INR in the UK (currently n=30) and for a number of reasons, it is not yet clear how many credential training posts will be required to further expand INR operator numbers at a rate that matches the development of MT services within the NHS.


The UK INR community is receptive to the concept of INR training for non-radiologists with the following reservations:


  1. While there is wide interest in INR training from other specialties, requirements for training and acquisition of experience are often underestimated.


  1. There are concerns that practitioners from a non-radiology background may desire outcomes of training that impair future INR and radiology service delivery (such as a preference not to report cerebrovascular imaging studies, or to only treat patients with aneurysms and not to contribute to 24/7 rotas for delivery of MT services).


  1. Other Royal Colleges have not yet made provision to recognise pre-CCT INR training time within their specialty training programs resulting in a significant additional training time penalty for StRs who are interested in the INR credential and a consequent requirement for funded post CCT training for consultants.




In the era of thrombectomy for acute stroke due to large vessel occlusion, alternative pathways to INR training in the UK are being developed (GMC credential). Widening access to INR training in the UK will facilitate ongoing expansion of INR operator numbers. However, the total number of INR practitioners required to staff future MT services remains unclear and for a number of reasons it is debatable whether trainee numbers will be a rate limiting step for MT service development in the longer term.


It is anticipated that the credential INR (Acute Stroke) will enable expansion of trainee numbers and will become the recognised pathway for INR procedural training for non-radiologists. Anyone seeking to pursue a local training process without formal qualification should be mindful of the potential limitations and risks associated with this approach, which would be particularly acute once a formal credential is in place.


R Lenthall, P White, P Flynn and N McConachie




Interventional Neuroradiology (INR) training for non-radiologists in the UK: current status (Feb 2019)


See also:

Download the Oxford AHSN Mechanical thrombectomy for acute ischaemic stroke: an implementation guide for the UK

The British Society of Neuroradiologists (BSNR) has produced Training Guidance for Mechanical Thrombectomy (Lenthall, R. et al. Clinical Radiology, Volume 72 , Issue 2 , 175.e11 – 175.e18) which details the training that will be required for practitioners from different clinical backgrounds to achieve the necessary skills and experience to effectively contribute to the acute stroke service. This guidance will underpin all routes to increasing the workforce.

The Supplementary Guidance to Facilitate the Training of Interventional Radiology Consultants to Undertake Stroke Thrombectomy has been produced by The Royal College of Radiologists, the British Society of Interventional Radiology, the British Society of Neuroradiologists and the UK Neurointerventional Group.

This BSNR/UKNG/RCR/BSIR collaboration released this guidance to help hospitals train more doctors in emergency mechanical thrombectomy for acute stroke.