Ventriculoperitoneal shunt dysfunction in adults secondary to conditions causing a transient increase in intra-abdominal pressure: report of three cases.

Abstract

Abstract OBJECTIVE AND IMPORTANCE: Ventriculoperitoneal (VP) shunts function because of the pressure differential between the intracranial space and the peritoneal cavity. The pressure in the peritoneal cavity is the lower of the two in a properly functioning shunt; thus, cerebrospinal fluid flows distally. Although not reported in the literature, adult constipation, ileus, or small bowel obstruction can alter this pressure balance and cause dysfunction. If not recognized as a transient, easily treated phenomenon, patients may be subjected to unnecessary shunt revisions. This study analyzed the occurrence of shunt malfunction in three adults secondary to transient increases in intra-abdominal pressure. CLINICAL PRESENTATION: Three patients with clinical symptoms and radiographic evidence of VP shunt malfunction at presentation were found to have transient conditions causing a significant increase in intra-abdominal pressure. These patients' records were evaluated with an emphasis on risk factors, treatments, and outcomes. INTERVENTION: After resolution of the patients' abdominal issues, clinical signs and symptoms of VP shunt dysfunction resolved within 24 hours. Radiographic evidence of the resolution of shunt failure also was observed. CONCLUSION: Shunt malfunction or dysfunction consumes many person-hours and healthcare dollars. This study provides anecdotal evidence that transient and easily reversible increases in the intra-abdominal pressure of adults with VP shunts can result in dysfunction. Although it may not be practical to delay shunt revision while attempting to correct constipation, ileus, or small bowel obstruction, clinicians treating patients with these abdominal conditions should be aware that they could cause transient VP shunt failure. It would seem prudent that patients with VP shunts be started on a prophylactic bowel regimen before surgical procedures to decrease the risk of this somewhat preventable result.