The applicability of fixed and adjustable gravitational shunt valves in two different clinical settings

Abstract

Background: Gravitational shunt valves and most recently the adjustable proSA® gravitational valve have been designed to counteract overdrainage and thereby improving clinical outcome. So far, the applicability in a broader mix of hydrocephalus patients is unrevealed. The aim of this study was to evaluate the utility of gravitational valves in two different clinical settings.

Methods: This retrospective double-center cohort study was enabled by two different shunt management policies. At Rigshospitalet, patients with a complicated shunt history receiving a proGAV® and proSA® shunt system during surgical revision were included, and clinical outcome in the follow-up periods before and after was compared. At Aarhus University Hospital, a combination of a proGAV® and a fixed (SA®) or adjustable (proSA®) gravitational valve was used in all shunt procedures. Clinical outcome in a 2-year follow-up period was compared to a cohort receiving non-gravitational valves in the period before the transition to gravitational valves.

Results: Twenty-two patients were included at Rigshospitalet. Mean follow-up time before and after proGAV® and proSA® implantation was 2.3 and 1.5 years, respectively. In each patient, roughly two surgical revisions (p 0.031) and two hospitalizations (p 0.009) were avoided each year after proGAV® and proSA® implantation. At Aarhus University Hospital, 90 patients with non-gravitational valves and 98 patients with gravitational valves were included. Changes in clinical outcome parameters and shunt survivals were either stable or statistically insignificant.

Conclusions: Gravitational valves are safe and useful in clinical practice and represent an equivalent alternative as a first-line shunt valve in a broad mix of patients, while proSA® valves should be considered for complex shunt patients.

Keywords: Cerebrospinal fluid shunt; Gravitational valve; Hydrocephalus; Shunt revision; Shunt survival; proSA.