Nonprogrammable and programmable cerebrospinal fluid shunt valves: a 5-year study

Abstract
Programmable valves (PVs) for shunting CSF have increasingly replaced nonprogrammable valves (NPVs). There have been only a few longer-term studies (≥ 5 years) conducted that have compared the effectiveness of NPVs with that of PVs for children with hydrocephalus, and only 1 study has reported NPVs as being favorable over PVs. The objective of this retrospective study was to compare the long-term survival of these 2 types of shunt valves. The authors collected data for all patients who underwent CSF shunt insertion or revision between January 1, 2000, and December 31, 2008. Patients underwent follow-up for a minimum of 2 years postoperatively. Statistical analyses were done using chi-square, Kaplan-Meier survival curve, and multivariate analyses. A total of 616 valves were implanted, of which 313 were PVs and 303 were NPVs. Of these, 253 were original shunt implantations and 363 were revisions. The proportion of 5-year survival for NPVs (45.8%) was significantly higher than that for PVs (19.8%) (p = 0.0005, log-rank). The NPVs that survived longer than 6 months also survived through the 5th year better than the PVs (p = 0.0001). The authors' data suggest that NPVs survive longer than PVs in children, but there is a need for prospective, case-control studies to confirm these data.