Developments in mechanical thrombectomy devices for the treatment of acute ischemic stroke

Abstract

Several recent prospective randomized controlled trials of endovascular stroke therapy using latest generation thrombectomy devices, so called stent-retrievers, have shown significantly improved clinical outcome compared to the standard treatment with intra-venous thrombolysis using r-tPA alone. Despite some differences in inclusion criteria between these studies, all required non-invasive vessel imaging to proof occlusion of a major brain supplying vessel. Furthermore, in most studies additional imaging techniques were used to exclude patients with already established large cerebral infarction or unfavorable collateral or penumbral status. Patients with small infarct volume, severe neurological deficits and in whom thrombectomy can be initiated within the first 6 hours after symptom onset seem to benefit the most. Therefore, mechanical thrombectomy using stent-retrievers in addition to intra-venous thrombolysis is recommended for the treatment of acute ischemic stroke with proven major vessel occlusion in the anterior circulation.

Keywords:

• Acute ischemic stroke
• endovascular stroke treatment
• mechanical thrombectomy
• stent-retriever
• proximal thrombectomy
• distal thrombectomy
• clinical trials
• clinical outcome

Key issues

• Mechanical thrombectomy in addition to intravenous thrombolysis, if eligible, is the recommended treatment of acute ischemic stroke due to large vessel occlusion of the anterior cerebral circulation up to 6 h after onset of symptoms.

• Patients eligible for intravenous thrombolysis should receive intravenous r-tPA, even if endovascular treatment is being considered. However, intravenous thrombolysis should not delay mechanical thrombectomy.

• Selected patients with proximal cerebral vessel occlusion with larger cerebral infarcts or with initiation of endovascular treatment after 6 h seem to benefit from mechanical thrombectomy provided that recanalization could be achieved, however, to a lesser extent.

• For mechanical thrombectomy, approved latest generation thrombectomy devices, so-called stent retrievers, should be considered.

• Occlusion of major brain supplying vessel must be documented with noninvasive imaging whenever possible before considering endovascular treatment.

• Additional noninvasive imaging techniques to determine infarct and penumbra size, such as multiphase CTA or perfusion imaging, can be used for patient selection.

• Patient management and decision-making should be made jointly by a multidisciplinary team including a stroke physician and a neurointerventionalist and endovascular treatment should be performed in experienced centers providing comprehensive stroke care.

Financial & competing interests disclosure

J. Gralla is the global PI of STAR - study and is a consultant for Covidien. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.