Syrinx shunts for syringomyelia: a systematic review and meta-analysis of syringosubarachnoid, syringoperitoneal, and syringopleural shunting.

Objective: Syringomyelia is a debilitating, progressive disease process that can lead to loss of neurological function in patients already experiencing significant compromise. Syringosubarachnoid, syringoperitoneal, and syringopleural shunts are accepted treatment options for patients with persistent syringomyelia, but direct comparisons have been lacking to date. The authors conducted a systematic review of the literature and meta-analysis to compare clinical outcomes between these three syrinx shunt modalities.

Methods: Utilizing PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews, Ovid Embase, PubMed, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, American College of Physicians Journal Club, and Database of Abstracts of Review of Effectiveness were searched to identify all potentially relevant studies published from inception until July 2020. Data were extracted and analyzed using meta-analysis of proportions. The primary study outcome was the rate of reoperation based on the initial shunt modality. Secondary outcomes included clinical improvement, clinical deterioration, and complications following shunt placement.

Results: A total of 22 articles describing 27 distinct treatment cohorts published between 1984 and 2019 satisfied the inclusion criteria. This captured 473 syrinx shunt procedures, 193 (41%) by syringosubarachnoid shunt, 153 (32%) by syringoperitoneal shunt, and 127 (27%) by syringopleural shunt, with an overall median clinical follow-up of 44 months. The pooled incidences of revision surgery were estimated as 13% for syringosubarachnoid, 28% for syringoperitoneal, and 10% for syringopleural shunts, respectively (p-interaction = 0.27). The rate of clinical improvement was estimated as 61% for syringosubarachnoid, 64% for syringoperitoneal, and 71% for syringopleural shunts. The rate of clinical deterioration following placement was estimated as 13% for syringosubarachnoid, 13% for syringoperitoneal, and 10% for syringopleural shunts.

Conclusions: The preferred modality of syrinx shunting remains a controversial topic for symptomatic syringomyelia. This study suggests that while all three modalities offer similar rates of clinical improvement and deterioration after placement, syringoperitoneal shunts have a greater rate of malfunction requiring surgical revision. These data also suggest that syringopleural shunts may offer the best rate of clinical improvement with the lowest rate of reoperation.