Utility of very high-pressure valves in persistent symptomatic shunt overdrainage.

Introduction: Shunt overdrainage is one of the long-term complications associated with ventriculoperitoneal shunts. Treatment of refractory cases may require further upgrading of both the valve opening pressure and antisiphon device. The aim of this paper is to describe the results of this combination in a selected group of patients.

Methods: Retrospective cohort study that included 18 pediatric patients between 2003-2022. Previous shunts were exchanged for the combination of a SOPHYSA Polaris® SPVA-300 valve and upgraded fixed or adjustable antigravitatory devices. The following variables were collected: etiology of the hydrocephalus, age at first shunt and type of valve, number of shunt revisions, other surgical procedures, age at inclusion, clinical and radiological outcomes, and follow-up time. A descriptive analysis was done with means, medians and ranges for quantitative variables; percentages and frequencies for the analysis of qualitative data.

Results: The median age at first shunt was two months (0-67). The mean number of shunt revisions before inclusion was three. Shunt removal was attempted in seven patients without success; temporary success was observed in two patients who underwent ETV. Two patients had previous cranial expansions. The mean age at inclusion was 9.1 years (2.7-15.2). After the shunt system was exchanged and upgraded, clinical improvement was observed in 94.4% (17/18) of patients, and radiological improvement was observed in 83.3% (15/18) of patients. The median follow-up was 21 months.

Conclusions: Before considering more invasive therapeutic measures, shunt system optimization by the combination of very high-pressure valves and upgraded in-line antisiphon devices is a valid and safe strategy for refractory symptomatic shunt overdrainage.