A review of mechanical thrombectomy techniques for acute ischemic stroke

Abstract

Mechanical thrombectomy is established as standard of care in the management of acute ischemic stroke due to large vessel occlusion and evidence-based guidelines for mechanical thrombectomy have been defined. As research continues to further expand the eligibility criteria for thrombectomy and the number of thrombectomy procedures increase worldwide, there is also growing focus on innovation of thrombectomy devices, procedural techniques, and related outcomes. Thrombectomy primarily involves use of stent retrievers and distal aspiration techniques, but variations and different combinations of techniques have been reported. As this is a rapidly evolving area in stroke management, there is debate as to which, if any, of these techniques leads to improved clinical outcomes over another and there is a lack of data comparing them. In this review, currently published and distinct techniques of mechanical thrombectomy are described methodically along with illustrations to aid in understanding the subtle differences between the techniques. The perceived benefits of each variation are discussed.

Keywords: Mechanical thrombectomy; ischemic stroke; recanalization; techniques.

Figure 1.

Illustration of standard mechanical thrombectomy techniques. Stent retriever alone: Stent-retriever deployed at the site of the thrombus (A) and retrieval of stent-retriever and thrombus within the guide catheter (B). Contact aspiration: Placement of aspiration catheter at the proximal tip of the thrombus (C), aspiration initiated (D) and retrieval of both aspiration catheter and thrombus inside the guide catheter (E). Combined stent retriever and aspiration: Deployment of stent-retriever at the site of thrombus and initiation of aspiration through the aspiration catheter (F) followed by retrieval of stent-retriever, thrombus and aspiration catheter as a unit through the guide catheter (G).

Figure 2.

CAPTIVE: continuous aspiration prior To intracranial vascular embolectomy. Deployment of stent-retriever under aspiration from catheter proximal to the thrombus (A), removal of microcatheter and advancement of aspiration catheter (B) and removal of stent-retriever, aspiration catheter and thrombus as a unit (C). SAVE: Stent-retriever Assisted Vacuum-locked Extraction technique. Deployment of stent-retriever, removal of the microcatheter and initiation of aspiration (D), advancement of the aspiration catheter to the proximal tip of the thrombus (E) and removal of stent-retriever, aspiration catheter and the thrombus as a unit under aspiration suction (F). ARTS: Aspiration-Retriever Technique for Stroke: Placement of an aspiration catheter proximally to thrombus (G), deployment of stent-retriever under constant aspiration (H), inflation of BGC and retrieval of the stent-retriever, the thrombus and the aspiration catheter as a unit through the BGC (I). STRAP: Stent Retrieval - Aspiration and Proximal Flow Arrest Placement of an aspiration catheter proximally to the thrombus (J), deployment of a stent-retriever and initiation of aspiration from aspiration catheter and BGC (K), followed by retrieval under constant suction (L). BADDASS: Balloon Guide with Large Bore Distal Access Catheter with Dual Aspiration with Stent-retriever as Standard. Partial deployment of stent-retriever with or without aspiration catheter on (M), advancement of aspiration catheter to proximal portion of thrombus, full deployment of the stent-retriever and removal of microcatheter (N), inflation of BGC and thrombus retrieval under constant suction from distal catheter and BGC (O). ASAP: A Stent-Retrieving into an Aspiration Catheter with Proximal Balloon Technique. Deployment of stent-retriever at the site of the thrombus while the aspiration catheter is under suction and BGC is inflated (P), the stent-retriever is the retrieved inside the aspiration catheter (Q) followed by removal of the aspiration catheter under continuous suction (R). PROTECT: Proximal Balloon Occlusion Together with Direct Thrombus Aspiration. Deployment of a stent-retriever at the site of the thrombus while suction is applied through the aspiration catheter and manual suction is done through the inflated BGC (S) followed by retrieval under constant suction through the aspiration catheter and through the BGC (T).