410 Treatment of Idiopathic Normal Pressure Hydrocephalus With a Novel Programmable Valve With Gravitational Unit: Prospective Evaluation of Efficacy, Safety and Costs

Abstract

INTRODUCTION: Programmable valves provide an equal or superior neurological outcome when compared to fixed pressure ones, with fewer complications, in treating idiopathic normal pressure hydrocephalus (iNPH) patients. Long-term costs of these treatments have not been properly compared in literature. METHODS: A prospective cohort of iNPH patients treated with programmable valve between January 2018 and May 2020 was compared to a historical cohort of iNPH patients treated with fixed pressure valve from January 2016 through December 2017. Our primary outcome was the mean cost of treating iNPH up to one year. Cost variables assessed included number of surgeries, length of ICU and hospital stay, and number of imaging tests. Efficacy in treating iNPH, measured by mean NPH Japanese Scale, and safety, measured by complications rates, were assessed as secondary outcomes. RESULTS: A total of 19 patients were analyzed in each group (mean age 75 years, the majority male). Comorbidities and clinical presentation were similar between groups. Both fixed pressure and programmable valve patients had neurological improvement over time (p < 0.001), but no difference was seen between groups (p = 0.104). The fixed pressure valve group had more complications than programmable valve group (52.6% vs 10.5%, respectively, p = 0.013). Annual treatment cost per patient was US$ 3,820 ± 2,231 in the fixed pressure valve group and US$ 3,108 ± 553 in the programmable valve group. Mean difference was US$712 (95% CI, 393 – 1,805) in favor of the programmable valve group. CONCLUSIONS: The novel programmable valve with gravitational unit had one-year treatment cost not higher than that of fixed-pressure valve, and resulted in similar efficacy and fewer complications.