Comparison of Programmable and Non-Programmable Shunts for Normal Pressure Hydrocephalus: A Meta-Analysis and Trial Sequential Analysis.

Abstract

The use of programmable ventriculoperitoneal shunt (P-VPS) in idiopathic normal pressure hydrocephalus (iNPH) has increased over the last two decades, however, there is no definitive evidence to favor them over non-programmable VPS (NP-VPS). Thus, there is a growing need for studies comparing these two procedures for their efficacy and safety profile in iNPH. In this study, we attempt to quantitatively summarize the findings of all the prospective and retrospective studies that have directly compared the P-VPS and NP-VPS in terms of efficacy, complications, or overall healthcare expenditure. A systematic search was performed of PubMed, the Cochrane Library databases, and Google Scholar for studies till June 2021 comparing the outcomes of P-VPS with NP-VPS. Four studies were finally included in the quantitative analysis. A trial sequential analysis was done to evaluate the need for further studies. The total rates of subdural collection (odds ratio (OR) 1.03; 95% Confidence interval (CI): 0.73-1.46; P = 0.85; I2 = 12%) as well as surgically evacuated subdural collection (OR 0.46; 95% CI: 0.14-1.55; P = 0.21; I2 = 75%) were not significantly different for P-VPS compared to NP-VPS with pooled data. Similarly, the rate of postoperative infection was found to be similar between the two types of VPS (OR 0.98; 95% CI: 0.39-2.5; P = 0.97; I2 = 0%). The trial sequential analysis (TSA) for the need of surgical evacuation of subdural collection and shunt revision revealed that the meta-analysis of the currently accrued information is not conclusive. Though, associated with higher initial costs, P-VPS does not seem to result in increased healthcare costs in the long run while enabling the surgeon to titrate the opening pressure and avoiding additional surgical procedures like shunt revision or evacuation of subdural collection at least theoretically. However, further trials with a greater sample size are needed to confirm these findings as the current accrued information size is insufficient to reach an unequivocal verdict.