Bone Overgrowth Causing a Proximal Ventriculoperitoneal Shunt Malfunction.

BACKGROUND: Hydrocephalus is an international disease process that is commonly treated surgically with a ventriculoperitoneal shunt. This device may be prone to malfunction, most commonly from obstruction, disconnection, or infection. CASE DESCRIPTION: A 35-year-old female with hydrocephalus and a ventriculoperitoneal shunt presented with altered mental status and imaging concerning for a shunt malfunction. Intraoperatively, she was found to have bone growing over and compressing the proximal occluder of the shunt valve, causing a mechanical obstruction. Removal of the bone allowed for egress of cerebrospinal fluid and return of proper shunt function. The patient did well postoperatively. CONCLUSION: Hydrocephalus, ventriculoperitoneal shunts, and shunt revisions represent a significant health burden and cost. Here we present an unusual cause of a shunt malfunction caused by bony overgrowth.