Abstract WP10: Incidence, Etiology And Predictors Of Mechanical Thrombectomy Failure

Background: Despite advances in endovascular techniques, mechanical thrombectomy fails to achieve successful revascularization in approximately 20% of patients. This study evaluates the incidence, and identifies the etiologies and predictors of failed thrombectomy in a contemporary series. Methods: A prospectively maintained database of MT between January 2013 and August 2021 was interrogated. We gathered demographic data, clinical presentation, procedural details and etiology of MT failure on adult patients who underwent MT with subsequent failed recanalization. Angiographic images were interpreted by an independent neuro-interventionalist. Results: Out of a total of 1010 thrombectomies, 120 (11.9%) were unsuccessful. Mean age was 66.8, 51.5% were male and 61.1% were Caucasian. The most common failure location was intracranially (93.3%) followed by failure at the arch and neck (3.3% each). Of those who failed intracranially, underlying intracranial stenosis (ICAS) was seen in 84 patients (70%). Compared to successful MT, failed MT patients had longer onset to puncture time (444 vs 351 minutes, p=0.012) and longer procedural time (55 vs 23 minutes, p=<0.001). Rescue stenting was more common in the successful MT group (12% vs 5.1%, p=0.024). Multivariate analysis demonstrated that DM (OR 1.82; 95% CI 1.05 - 3.16, p=0.03), more than one pass (OR 4.39; 95% CI 1.96 - 9.80, p<0.001), and longer procedural time (OR 1.06, 95% CI 1.03-1.09, p=<0.001) were independently associated with unsuccessful recanalization. Conclusion: Failed MT was encountered in approximately 12% of cases. The most common cause of failed MT was underlying ICAS. Further studies to evaluate better treatment modalities of ICAS related LVO are warranted.