Abstract WP52: There is No Association Between the Number of Stent Retriever Passes & the Incidence of Hemorrhagic Transformation for Patients Undergoing Mechanical Thrombectomy

Abstract

Background: Previous research has primarily investigated the association between hemorrhagic transformation (HT) incidence and baseline variables (i.e. pre-procedural variables) rather than the association between HT incidence and endovascular treatment (EVT) procedural variables (e.g. the number of passes with a stent retriever). Current stent retriever guidelines recommend a maximum of 2 passes per device and not more than 3 passes per vessel. Objective: To assess the association, if any, that exists between the number of passes with a stent retriever and the incidence of HT for patients undergoing mechanical thrombectomy. Materials and Methods: Data from patients who underwent EVT with a Trevo, Solitaire, or Penumbra stent retriever from the years 2012 to 2018 was collected and categorized according to the incidence of HT. HT was defined as any intracranial hemorrhage in the territory of the initial ischemic event within admission and determined via CT scan read by radiology. Univariate and bivariate statistical analyses were conducted on the number of passes per procedure with a stent retriever, patient demographic data, patient morbidities, and patient outcomes to investigate their association with HT incidence. Results: Of 329 total patients, 46 (14%) had HT. The HT group had an average[SD] of 1.65[0.67] and range of [1-3] passes while the non-HT group had an average[SD] of 1.63[0.86] and range of [1-5] passes per procedure. Admission NIHSS score (p = 0.0003) and the incidence of diabetes mellitus (DM) (p=0.05) were significantly higher in the HT group. Upon bivariate logistic regression, the number of passes failed to show any association with HT (p = 0.804) while admission NIHSS score was found to have an OR of 1.07 (95% CI: 1.03 - 1.12, p = 0.001) with HT incidence. Conclusion: No significant association was found between HT incidence and the number of passes with a stent retriever. Further research investigating additional EVT procedural variables is warranted.