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

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.

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.

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.

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.