Neurovascular conflict patterns in glossopharyngeal neuralgia: a systematic review and meta-analysis of offending vessels and outcomes after microvascular decompression

Background: Microvascular decompression (MVD) for glossopharyngeal neuralgia (GPN) presumes a compressive neurovascular conflict at the glossopharyngeal-vagal root entry zone, but the distribution of offending vessels has never been quantified across series. Objective: To estimate the pooled prevalence of each offending vessel identified at MVD for GPN, alongside pain relief, recurrence, mortality and complications. Methods: PubMed/MEDLINE, Embase, Web of Science and Cochrane CENTRAL were searched from inception through August 2026. Studies with at least five GPN patients undergoing MVD and extractable outcomes were included. Proportions were pooled using the Freeman-Tukey double arcsine transformation and a DerSimonian-Laird random-effects model. Risk of bias was assessed with the Newcastle-Ottawa Scale (NOS). Results: Nineteen observational studies (1,000 MVD patients) were included, and methodological quality was acceptable to moderate (modified NOS median 5/6; comparative cohorts 6–7/9). Fifteen studies (674 patients) reported vessel-specific findings. The posterior inferior cerebellar artery (PICA) was implicated, alone or in combination, in 87% of patients (95% confidence interval [CI] 83–90), the least heterogeneous outcome (I² = 27.9%). Vertebral artery involvement was 12% (7–17), anterior inferior cerebellar artery involvement 7% (4–12) and venous conflict 3% (1–6). Multiple-vessel conflict was present in 14% (9–20). Immediate pain relief was 94% (92–97) and relief at last follow-up 90% (85–94) after a weighted mean follow-up of 66 months, with recurrence in 4% (1–9). Five deaths occurred (0.5%), four in earlier surgical eras. Sensitivity analyses for cohort overlap, rootlet section and unretrieved reports changed no estimate by 2 percentage points or more. Conclusion: The PICA was involved in about nine of ten patients with vessel data, the most consistent estimate in the review. About one in seven patients had more than one offending vessel, supporting full-length inspection of the IX-X rootlets rather than treatment of the first conflict encountered.