Comparing Postoperative Stroke Incidence in Moyamoya Disease: Single-Barrel versus Double-Barrel STA-MCA Bypass—A Meta-analysis

Background: Moyamoya disease (MMD) involves progressive stenosis of intracranial arteries and compensatory collateral vessel formation. While the single-barrel STA-MCA bypass remains a cornerstone treatment, modifications such as the double-barrel bypass offer potential advantages via higher postoperative flow and draw, although a longer operative time is also required. Currently, there is a lack of consensus regarding the impact of double-barrel bypass techniques on the incidence of postoperative stroke after direct bypass for adult and pediatric patients with MMD.

Methods: We performed a PRISMA-compliant systematic review of MEDLINE and Embase from inception through March 2024. A supplemental bibliography review in Google Scholar was also performed to screen for additional candidate citations not captured by the primary screen. Among 62 candidate citations, 16 underwent full-text review, and 5 met study criteria and were included in a meta-analysis of proportions using random-effects modeling. The supplemental screen yielded two candidate citations that were ultimately included in the meta-analysis.

Results: The pooled odds ratio (OR) for postoperative stroke after single-barrel bypass as compared to double-barrel bypass was 1.19 (95% CI = 0.3–4.73). Studies reported either median or mean follow up times. Mean follow-up time was 20.2 months (range, 7–190) based on data from two studies reporting mean follow-up times and two studies reporting median follow-up times. One study did not report follow up time. Inter-study heterogeneity was minimal (I ² = 0%). In order to assess for latent confounding factors due to the inclusion of mixed study populations that were majority MMD, a supplemental sensitivity analysis was performed excluding Takanari et al (2015) and Cherian et al (2018). This yielded a pooled OR of 1.12 (95% CI = 0.23–5.46), validating the findings of the primary analysis. A second sensitivity analysis excluding studies with mean or median follow-up times less than 12 months yielded similar results (OR: 1.16 (95% CI = 0.05–27.97). Funnel plots and Egger’s test were negative for publication bias.

Conclusion: We report a novel meta-analysis comparing single-barrel and double-barrel techniques for direct extracranial–intracranial bypass for the treatment of MMD. Double-barrel techniques do not appear to provide additional postoperative stroke protection; however, given the relatively limited follow-up times, these results may under-represent the long-term benefits of a double-barrel bypass technique. Well-controlled long-term studies are needed to better interrogate the optimal treatment strategies for this vulnerable patient population.

Publication History

Article published online:
07 February 2025