Adult Internal Cerebrospinal Fluid Shunt Overall Survival: A Meta-Analysis of Restricted Mean Survival Times from Reconstructed Kaplan-Meier Data

Objective: To assess the overall survival (OS) of internal cerebrospinal fluid shunt (ICSFS) in the adult population.

Methods: MEDLINE database was searched from 2000 to 2023 to identify studies reporting on ICSFS OS. Only articles reporting on adult ICSFS OS by a Kaplan-Meier (KM) OS curve were included. Numerical data were extracted from KM curves and were then reconstructed to estimate 3, 6, 9, 12, 18, 24, 36, 48, and 60 months restricted mean survival times (RMSTs). RMSTs of ICSFS and its SE at each time of interest were used as summary measure and primary outcome across studies. To account for the effect of between-study heterogeneity, RMSTs were pooled using a random effects model.

Results: Out of 421 screened studies, only 6 were included in the meta-analysis. Calculated ICSFS OS at 3, 6, 9, 12, 18, 24, 36, 48, and 60 months were 92.4% (95% CI, 89.6-95.2), 89.5% (95% CI, 86.3-92.8), 87.5% (95% CI, 83.9-91.1), 85.2% (95% CI, 80.4-90.0), 83.4% (95% CI, 79.0-87.9), 81.6% (95% CI, 76.7-86.5), 78.8% (95% CI, 72.9-84.6), 76.7% (95% CI, 70.3-83.1), and 74.5% (95% CI, 67.8-81.1), respectively. There was a significant heterogeneity as indicated by a high I² value of 82.5% (95% CI, 63.1-91.7). Heterogeneity test of Q = 28.63 was also significant (P < 0.001).

Conclusions: On contrary to what one might think, there are few available studies assessing adult ICSFS OS. We used a novel technique to meta-analyze adult ICSFS OS. ICSFS failure rate is maximal within the 3 to 6 postoperative months. Afterward, the risk slowly decreases over time. At 5 years, less than three quarters of the patients still have a naïve functional ICSFS never revised.