Ventriculoperitoneal shunt complications in an adult population: A comparison of various shunt designs to prevent overdrainage.

Background: Overdrainage after cerebrospinal fluid diversion remains a significant morbidity. The hydrostatic, gravitational force in the upright position can aggravate this. Siphon control (SC) mechanisms, as well as programmable and flow regulating devices, were developed to counteract this. However, limited studies have evaluated their safety and efficacy. In this study, direct comparisons of the complication rates between siphon control (SC) and non-SC (NSC), fixed versus programmable, and flow- versus pressure regulating valves are undertaken.

Methods: A retrospective chart review was performed over all shunt implantations from January 2011 to December 2016 within the Houston Methodist Hospital system. Complication rates within 6 months of the operative date, including infection, subdural hematoma, malfunction, and any other shunt-related complication, were analyzed via Fisher's exact test, with < 0.05 regarded as significant. Subgroup analyses based on diagnoses - normal pressure hydrocephalus (HCP), pseudotumor cerebri, or other HCP - were also performed.

Results: The overall shunt-related complication rate in this study was 19%. Overall rates of infection, shunt failure, and readmission within 180 days were 3%, 11%, and 34%, respectively. No difference was seen between SC and NSC groups in any complication rate overall or on subgroup analyses. When comparing fixed versus programmable and flow- versus pressure-regulating valves, the latter in each analysis had significantly lower malfunction and total complication rates.

Conclusions: Programmable and pressure regulating devices may lead to lower shunt malfunction and total complication rates. Proper patient selection should guide valve choice. Future prospective studies may further elucidate the difference in complication rates between these various shunt designs.