Thrombectomy Using “Clamping Embolus with Semi-Retrieval” Technique in Acute Ischemic Stroke

Background

Embolization of thrombus fragments in new or downstream vascular territories is a potential adverse event in neurothrombectomy, requiring additional repeated thrombectomy attempts. This study aims to describe technical results of the thrombectomy with clamping embolus technique (TCET) method in acute ischemic stroke. This study also aims to evaluate the efficiency of mechanical thrombectomy by TCET, and to compare it with conventional stent retriever thrombectomy (CSRT).

Materials and Methods

A retrospective analysis was performed in 52 consecutive patients treated between January 2015 and October 2016 for intracranial large vessel occlusion by stent retriever thrombectomy. Recanalization rates, procedure durations, and thrombectomy attempts were compared between the TCET and the CSRT groups.

Results

Successful recanalization (thrombolysis in cerebral infarction [TICI] 2b or 3) with TCET was achieved in 91.7% (22 of 24) versus 92.9% (26 of 28) in the CSRT group (P = .921). To preserve the restored patency of severely affected atherosclerotic intracranial vessels, 7 and 8 patients received angioplasty or stenting in the TCET and CSRT groups, respectively. In embolic cases, the number of thrombectomy attempts with TCET was significantly lower than that obtained with CSRT (1.7 ± .2 versus 2.6 ± .5, respectively; P = .001); the one-pass thrombectomy rate was significantly higher in the TCET group than in the CSRT-treated patients (58.8% versus 25.0%, respectively; P = .014). Procedure duration was significantly shorter by TCET than by CSRT (35.8 ± 5.8 minutes versus 55.5 ± 7.2 minutes, respectively; P = .001).

Conclusions

The efficiency of mechanical thrombectomy by TCET in acute ischemic stroke might be improved compared with CSRT.

Introduction

Acute ischemic stroke due to emergent large vessel occlusion (ELVO) is one of the leading causes of disability and mortality worldwide.1, 2 To increase low recanalization rates of tissue plasminogen activator (tPA), mechanical thrombectomy with suction or retrieval instruments has been proposed. Five randomized studies demonstrated that mechanical thrombectomy with stent retrievers is superior to intravenous thrombolysis alone, and CSRT is considered the standard treatment for acute ischemic stroke with ELVO.3, 4, 5, 6, 7

Recently, different studies in vivo and in vitro have demonstrated that interactions between the thrombus and stent retriever are only superficial, with no thrombus integration into the stent retriever.8, 9, 10 Therefore, during retrieval, the thrombus rolls toward the stent retriever's tip before being introduced into the guide catheter; this causes clot fragmentation with embolization to new or downstream territories. Procedural-related embolic complications have been observed with various stent retrievers, with distinct designs, radial forces, and strut structures.11, 12, 13, 14, 15, 16, 17

Since CSRT became available at our institution in July 2012, it has been used in all thrombectomy cases until January 2016. Thrombectomy with clamping embolus technique (TCET) method was used since then. Here, we describe the technical results from all consecutive thrombectomy cases, comparing CSRT treatment in 2015 with the TCET group in 2016. We aimed to assess and highlight potential differences in recanalization rates, procedural times, thrombectomy attempt numbers, and one-pass thrombectomy rates between these 2 patient cohorts.