Transcirculation Approaches to Endovascular Flow Diversion of Intracranial Aneurysms: A Systematic Review and Technique Commentary

Introduction: Flow diversion (FD) of intracranial aneurysms (IAs) is an increasingly utilized and efficacious treatment modality. Transcirculation approaches, or approaches that cross the contralateral or anteroposterior arterial supply prior to reaching a target vessel, have been used to treat cerebrovascular pathologies when traditional approaches are unsuitable or require intraoperative complication management. The present study sought to determine the safety and efficacy of transcirculation approaches in the treatment of IAs with FD.

Methods: A systematic review of the PubMed, Scopus, Web of Science, and Embase databases was completed per PRISMA guidelines. Studies were included if they described transcirculation approaches in adult patients undergoing FD of IAs. Outcomes of interest included intraoperative complications and aneurysm occlusion rates.

Results: Twelve studies with nineteen (N=19) patients (89.5% female) were identified with a mean age of 54.1 years. Wide-necked (N=5, 26.3%) and saccular (N=5, 26.3%) aneurysms were most represented, while 57.9% (N=11) of IAs were non-ruptured and 15.8% (N=3) of IAs were ruptured (N=5, unspecified rupture status). The mean aneurysm sac and neck size were 16.9 mm and 11.9 mm, respectively. The most commonly deployed flow diverter was the Pipeline Embolization Device (N=14, 73.9%). Successful FD (complete occlusion and/or good wall apposition) was recorded in 84.6% of qualifying patients with follow-up data while two patients (15.4%) developed an intraoperative carotid-cavernous fistula.

Conclusion : Transcirculation approaches to FD offer neurointerventionalists a safe and efficacious method for device deployment, rescue scenarios, and treatment of difficult IAs. Prospective studies may determine the most appropriate indications for transcirculation approaches in IA patients undergoing FD.