Endoscopic third ventriculostomy (ETV) for Chiari 1 malformation: a systematic review and meta-analysis

Meta-analysis and systematic review. To understand the role of endoscopic third ventriculostomy (ETV) for the treatment of concurrent Chiari Malformation Type I (CMI) and hydrocephalus in adults. A literature search on PubMed and Medline with MeSH terms relating to ETV and CMI identified 155 articles between 1988 and 2024. After excluding pediatric cases and other CNS pathologies with associated CMI, 11 articles met inclusion criteria. The Newcastle-Ottawa Scale was identified to assess heterogeneity and risk of bias among the 11 studies analyzed in this systematic-review and meta-analyses compared pre- and post-operative outcomes to examine the use of ETV as a treatment modality for CMI with hydrocephalus. From the 11 included studies, 35 cases of concurrent CMI and hydrocephalus treated with ETV were identified. ETV provided a pooled rate of symptom resolution or improvement of 66%. Additionally, meta-analysis discovered the following pooled rates: a reduction of tonsillar descent in 94% of patients, decreased ventriculomegaly in 94%, and ETV patency in 99%. Syringomyelia, nausea, papilledema and cerebellar dysfunction did not have sufficient numbers for meaningful statistical analyses. However, in each of these categories, more than 85% of the symptoms or radiographic findings improved. This review summarizes the safety and efficacy of ETV for the concurrent management of acquired CMI with hydrocephalus. Specifically, ETV improves radiological outcomes of both ventriculomegaly and tonsillar descent as well as the most prevalent neurological symptom, headaches.