Comparing the efficacy of Ventriculoperitoneal Shunts with Lumboperitoneal Shunts in the treatment of Idiopathic Normal Pressure Hydrocephalus: A Systematic Review and Meta-Analysis

Abstract Introduction Ventriculoperitoneal (VP) and Lumboperitoneal (LP) shunts are the most common treatments for Idiopathic Normal Pressure Hydrocephalus (iNPH). Shunt procedure choice is generally based on surgeon on preference rather than evidence. We performed a systematic review and meta-analysis to address this gap for evidence-based shunt selection in iNPH treatment. Methods Publications on post-operative outcomes for LP and VP shunts in iNPH were identified in MEDLINE and EMBASE. Papers were selected based on pre-specified inclusion and exclusion criteria and meta-analysis was conducted for outcome measures after shunt procedure. Results 17 papers were included. LP Shunt patients showed greater cognitive improvement with an average increase of 2.00 points (95% CI: 1.08; 2.93, p < 0.0001) on their MMSE score post-operatively compared to VP shunt patients who improved on average by 1.30 points (95% CI: 0.81; 1.79, p < 0.0001). The LP group had considerable heterogeneity (I 2 = 66.42%, p = 0.0003) whereas the VP shunt group had minimal heterogeneity (I 2 = 0.00%, p = 0.8447) reflecting more uniformity across its included studies. For overall symptomatic improvement measured by the iNPHGS, VP shunts patients demonstrated a larger reduction in overall symptom scores with an average decrease of 2.91 points (95% CI: -3.78; -2.05, p < 0.0001) but with a high heterogeneity (I 2 = 79.12%, p = 0.0012) compared to LP shunt patients with an average reduction of 1.91 points (95% CI: -2.31; -1.51, p < 0.0001) with no detected heterogeneity (I 2 = 0.00%, p = 0.8454). Conclusions Our findings demonstrate that LP and VP shunts show differing patterns of improvement across the cognitive domain and the broader iNPH triad, with LP shunting showing greater cognitive improvement and VP shunting showing greater overall symptomatic improvement. These differences represent a signal warranting further investigation, specifically whether symptom profiles should inform shunt selection.