Pseudofailure of Ventriculoperitoneal Shunt due to Drug-Resistant Constipation, Dramatically Responsive to Rectal Tube Placement: Pitfall Case Series of Avoidable Shunt Revision.

Abstract

Ventriculoperitoneal shunt placement is a common standard treatment for hydrocephalus, and these shunts function appropriately in the presence of a pressure gradient between the ventricular and abdominal cavities. We encountered 2 cases of shunt malfunction that was due to an increase in intra-abdominal pressure, mainly caused by constipation and excessive accumulation of enteric gas. Although aggressive bowel regimens were implemented, this management failed in both patients. Careful physical examination revealed unusually elevated tonus of the anus sphincter muscle, and a fecal incontinence catheter was inserted into the rectum. Following this procedure, constipation rapidly improved together with a marked reduction in enteric gas, leading to a normalization of ventricular size on imaging and neurologic improvements. Both patients were able to avoid unnecessary surgical exploration or shunt revision. Constipation is one of the differential diagnoses of ventriculoperitoneal shunt malfunction, and bowel regimens are the first-line treatment. However, some cases can prove resistant to medical therapy, and mechanical tube placement can provide an alternative or additional solution. Before proceeding to surgical exploration, the intra-abdominal environment should be properly assessed and every option should be explored to address underlying causes of shunt failure to avoid unnecessary intervention.