Anatomic variations in basilar artery termination: a systematic review and meta-analysis with presentation of an illustrative case.

PURPOSE: Despite extensive literature on anatomical variations of the basilar artery, evidence on its termination patterns is limited. We sought out to systematically pool the prevalence of basilar artery termination variations and describe their neurointerventional implications with an illustrative case.

METHODS

We conducted a systematic review and meta-analysis of human basilar artery termination patterns in accordance with PRISMA guidelines. PubMed, Ovid MEDLINE, Web of Science, and Scopus were systematically searched. A risk of bias assessment was performed using the JBI critical appraisal tool. A meta-analysis of proportions was performed in R using random-effects models. Heterogeneity was assessed, and pre-specified subgroup analyses were conducted based on study type (deceased donor vs. imaging). We also present a case of basilar artery non-furcation identified during a dissection.

RESULTS

From 8469 initial records, 31 articles were eligible for quantitative analysis. The classic bifurcation pattern was most common, with a pooled prevalence of 85.94% [95% CI 56.65-96.62%]. The estimated pooled prevalences for variations were: non-furcation 8.95% [95% CI 6.20-12.74%], trifurcation 7.05% [95% CI 3.56-13.50%], quadrifurcation 5.30% [95% CI 2.16-12.45%], and pentafurcation 2.92% [95% CI 1.08-7.67%]. Hexafurcation was reported in a single study (0.87%). Imaging studies generally reported higher prevalence for variations compared to deceased donor cohorts.

CONCLUSION

A significant proportion (14% of the population) possess variations, with non-furcation and trifurcation being most common. An understanding of these anatomical variations, as highlighted by our review and case presentation, is critical for clinical practice in neuroradiology and neurosurgery.