Transcirculation Approaches to Endovascular Flow Diversion of Intracranial Aneurysms: A Systematic Review With Technical Considerations.

Background and objectives: Flow diversion (FD) of intracranial aneurysms (IAs) is an increasingly used and efficacious treatment modality. Transcirculation approaches, or approaches that cross the contralateral or anteroposterior arterial supply before reaching a target vessel, have been used to treat cerebrovascular pathologies when traditional approaches are unsuitable or require intraoperative complication management. This study sought to review IAs treated with FD using a transcirculation approach to determine the technique's safety and efficacy.

Methods: A systematic review of the PubMed, Scopus, Web of Science, and Embase databases was completed per Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were included if they described transcirculation approaches in adult patients with IAs undergoing FD. Outcomes of interest included intraoperative complications and aneurysm occlusion rates.

Results: Twelve studies with 19 patients (N = 19, mean age = 54.1 y, 89.5% female) were identified. Wide-necked (N = 5, 26.3%) and saccular (N = 5, 26.3%) aneurysms were most represented, while 57.9% (N = 11) of aneurysms were unruptured and 15.8% (N = 3) of aneurysms were ruptured. 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 2 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 challenging anatomy. Prospective studies may determine the most appropriate indications for transcirculation approaches to FD, while novel, lower profile devices may improve its technical feasibility and safety.