Cerebrospinal fluid diversion from the cisterna magna in patients with idiopathic intracranial hypertension and slit ventricles: long-term effectiveness, revision rates, and clinical outcomes

Objective Idiopathic intracranial hypertension (IIH) is a cerebrospinal fluid (CSF) disorder defect that is frequently treated with CSF shunts. Shunts utilizing the cisterna magna as a proximal reservoir have been described in literature, however, long-term outcomes are unknown. The present study aims to describe the long-term effectiveness, revision rates, and clinical outcomes of this shunt in 14 patients with IIH and slit ventricles. Methods A single-center retrospective review of 14 IIH patients treated by cisterna magna shunts was performed. Shunt histories, including revision rate and time until first shunt failure for ventricular, lumbar, and cisterna magna shunts were recorded. “Revision rate” was calculated as the total number of shunt revisions over years of total shunt placement. The average follow-up time was 12.08 years. Results The mean age at first cisterna magna shunt placement was 18.1 years (6.6 – 43.3 years) and all patients had radiological evidence of slit ventricles. Cisterna magna shunts improved or resolved clinical symptoms for all 14 patients and had a lower rate of revisions (0.42 revision/year) compared to ventricular (0.72 revision/year) and lumbar (1.30 revision/year) shunts. Of the 11 patients still requiring CSF diversion at the end of the study, eight had functioning shunts that utilized the cisterna magna. Conclusions The cisterna magna shunt may be a suitable option for patients with IIH and slit ventricles. Further study is needed to understand the clinical utility of this shunt for the population in which it is indicated.