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

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.

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.

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.

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.