Brain aneurysm rupture during mechanical thrombectomy for large vessel occlusion: Technical case series and complication avoidance strategies.

Endovascular therapy became the mainstream treatment for patients with acute stroke due to emergent large vessel occlusion (LVO). With increasing number of interventions, it is not uncommon for incidental vascular pathologies to be found during mechanical thrombectomy. Overall, intracranial aneurysms can occur in up to 4% of the population, but previous studies suggest a slightly higher prevalence of intracranial aneurysms in stroke patients as they may share common risk factors. We report on three patients with acute stroke secondary to LVO undergoing mechanical thrombectomy with brain aneurysms incidentally discovered and discuss the potential implications and technical considerations of performing revascularization in these scenarios. In the first case, a patient treated with stent-retriever and aspiration developed a carotid-cavernous fistula without clinical repercussion. The second case illustrates an internal carotid artery posterior communicating segment aneurysm rupture with a massive subarachnoid hemorrhage. The third case exemplifies an unruptured middle cerebral artery bifurcation aneurysm related to an M2 occlusion managed with a different strategy, avoiding aneurysm rupture. Intraprocedural aneurysm rupture is a potential complication during mechanical thrombectomy, especially when anatomical challenges are present. Interventionalists should be aware of the potential risk and constraints in this setting in order to mitigate adverse events.