Vasospasm as a major complication after acute mechanical thrombectomy with stent retrievers

Mechanical thrombectomy using a stent retriever for acute large vessel occlusion is indispensable in stroke treatment, however, vasospasm may occur. The objective of this retrospective study was to investigate which cases are more likely to experience vasospasm after thrombectomy with stent retrievers.

We included 29 patients diagnosed with acute cardiogenic cerebral embolism who were treated with stent retrievers at our facility from December 2014 to December 2017. Atherothrombotic brain infarction cases were excluded because it was difficult to evaluate for vasospasms. Vasospasm was defined as reversible arterial narrowing of <80% of the normal vessel diameter after usage of the stent retriever. The age, sex, type of stent retriever, occlusion site, number of procedures, thrombolysis in cerebral infarction (TICI) grade, degree of vasospasm, intracranial hemorrhage by the procedure, and neurological outcomes were analyzed.

Among the 29 cases, 12 (41.4%) resulted in vasospasm; nine cases were mild (20-50% stenosis) and 3 cases were severe (≥50% stenosis). Vasospasm frequently occurred in the distal part of the anterior circulation when compared to the proximal part. In addition, the frequency of vasospasm increased as the number of procedures increased. Pooled analysis showed significant difference in the intravenous tissue-type plasminogen activator group (P = 0.029). There was no significant difference in the other groups.

Stent retrievers appear to cause vasospasm more than expected when including mild cases. Vasospasm tends to occur especially in cases with IV-tPA; prognosis is generally good, and it rarely requires any treatment.