STA-MCA Double-Barrel Bypass: A Systematic Review of Technique and Single-Arm Meta-Analysis of Outcomes.

INTRODUCTION: Conventionally, one branch of the superficial temporal artery (STA) is utilized to revascularize the middle cerebral artery (MCA). However, there is the possibility of utilizing both branches of the STA when performing the bypass, characterizing the double-barrel (DB) STA-MCA bypass. Notably, a lack of studies evaluating this technique led the authors to conduct a systematic review and single-arm meta-analysis. METHODS: PubMed, Embase and Web of Science were searched systematically for publications of DB-STA-MCA bypass on November 1st, 2023. The findings were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Case reports were not included for statistical analysis purposes. RESULTS: The review included 408 patients and 534 bypasses from 34 studies. The main etiology was Moyamoya disease (64.6%), followed by cerebral ischemia (22.2%) and aneurysms (12.5%). The median of the mean follow-ups of each study was 12.8 months (range 1.5-87.9). The postoperative patency was 100%. The follow-up patency was 98% (95% CI: 96%-100%; I2 = 0%). The procedure-related mortality was 0% (95% CI: 0%-1%; I2 = 0%). Aneurysms obtained 87% (95% CI: 72%-100%; I2 = 4%) of good clinical outcomes, while Moyamoya disease yielded a rate of 70% (95% CI: 10%-100%; I2 = 97%). Ischemic complications occurred at a rate of 6% (95% CI: 2%-11%; I2 = 36%), while hemorrhagic occurred at 6% (95% CI: 1%-11%; I2 = 56%). Hyperperfusion syndrome rate was calculated as 18% (7%-30%; I2 = 55%) for Moyamoya disease. CONCLUSIONS: The procedure appears to be safe, with excellent patency rates. The clinical efficacy for ischemic and Moyamoya diseases warrants further standardized robust investigation with a broader number of patients, and aneurysm studies are required to enhance sample sizes. The main complication for the Moyamoya subgroup is hyperperfusion syndrome.

Maxillary artery utilization in subcranial-intracranial bypass procedures: a comprehensive systematic review and pooled analysis.

The utilization of the internal maxillary artery (IMAX) in subcranial-intracranial bypass for revascularization in complex aneurysms, tumors, or refractory ischemia shows promise. However, robust evidence concerning its outcomes is lacking. Hence, the authors embarked on a systematic review with pooled analysis to elucidate the efficacy of this approach. We systematically searched PubMed, Embase, and Web of Science databases following PRISMA guidelines. Included articles used the IMAX as a donor vessel for revascularizing an intracranial area and reported at least one of the following outcomes: patency, complications, or clinical data. Favorable outcomes were defined as the absence of neurologic deficits or improvement in the baseline condition. Complications were considered any adverse event directly related to the procedure. Out of 418 retrieved articles, 26 were included, involving 183 patients. Among them, 119 had aneurysms, 41 experienced ischemic strokes (transient or not), 2 had arterial occlusions, and 3 had neoplasia. Furthermore, 91.8% of bypasses used radial artery grafts, and 87.9% revascularized the middle cerebral artery territory. The median average follow-up period was 12 months (0.3-53.1). The post-operation patency rate was 99% (95% CI: 97-100%; I2=0%), while the patency rate at follow-up was 82% (95% CI: 68-96%; I2=77%). Complications occurred in 21% of cases (95% CI: 9-32%; I2=58%), with no significant procedure-related mortality in 0% (95% CI: 0-2%; I2=0%). Favorable outcomes were observed in 88% of patients (95% CI: 81-96%; I2=0%), and only 3% experienced ischemia (95% CI: 0-6%; I2=0%). The subcranial-intracranial bypass with the IMAX shows excellent postoperative patency and considerable favorable clinical outcomes. While complications exist, the procedure carries a minimal risk of mortality. However, long-term patency presents heterogeneous findings, warranting additional research.