Abstract 307: Mechanical Thrombectomy of Superior Cerebellar Artery Occlusion: Case Report and Literature Review

Introduction Distal medium vessel occlusions (DMVOs) account for 25‐40% of acute ischemic stroke (AIS). Mechanical thrombectomy (MT) has demonstrated similar rates of reperfusion in DMVOs as compared to large vessel occlusions (LVO). While randomized clinical trials have not demonstrated clear superiority of MT over best medical management (BMM) in DMVOs, several retrospective studies suggest improved functional outcomes with intervention. Occlusion of the superior cerebellar artery (SCA) represents a particularly rare subset of AIS. We present a single institutional case and literature review assessing the role and outcomes of MT for SCA stroke. Methods We retrospectively reviewed one case of SCA occlusion treated with aspiration thrombectomy. Additionally, a systematic literature search was performed using the following terms: (superior cerebellar artery) AND (mechanical thrombectomy OR embolectomy OR endovascular thrombectomy). Reported cases were analyzed for clinical presentation, imaging, treatment approach, and outcomes. Descriptive statistics were performed. Results A total of 19 cases of SCA occlusion treated with MT were identified, including 6 isolated SCA events and 12 secondary SCA occlusions from basilar or posterior cerebral artery strokes. Median NIHSS at presentation was 13. Isolated SCA occlusions had lower initial NIHSS (mean 5.8) compared with secondary occlusions (mean 17.8). Thirteen patients received IV thrombolysis. Aspiration‐only thrombectomy was used in 8 cases, stent retriever in 4, and a combined or rescue strategy in 4. Two patients received intra‐arterial tPA. There was 1 case of perforation prior to MT being performed. Complete recanalization (mTICI 2C‐3) was achieved in 57.89% overall, including 83.33% of isolated and 41.67% of secondary occlusions. Of 16 patients with outcome data, 12 (75%) improved clinically, while 4 patients had similar neurological function as compared to presentation or experienced clinical deterioration. In cases of isolated SCA occlusion, 83.33% of patients experienced clinical improvement, whereas in secondary SCA occlusions only 66.67% of patients experienced clinical improvement. There were 3 reported complications (16.67% of cases), subarachnoid hemorrhage in 2 cases and 1 case of perforation. This resulted in 2 patient deaths and 1 patient discharged with an mRS of 4. Conclusions Overall, MT performed for SCA occlusion is rare. This review demonstrates that MT can lead to clinical improvement but has risk of injury to posterior circulation vessels resulting in perforation or SAH. Less severe NIHSS at presentation, complete recanalization and clinical improvement occurred at higher rates in the isolated SCA occlusion group. Our review lacks a medical management comparison group, so we are unable to determine if MT is more effective than past BMT.