Radionuclide shuntogram demonstrating migration of distal ventriculoperitoneal shunt tubing out of the peritoneal cavity.

An 81-year-old man with a history of ventriculoperitoneal (V-P) shunt placement for symptomatic normal pressure hydrocephalus presented with recurrence of confusion and gait disturbance. Radionuclide cisternography demonstrated loculation of In-111 DTPA in the abdominal wall. A soft tissue mass palpated at the location of tracer accumulation was confirmed to be extraperitoneal pooling of fluid at the site of coiling of the distal shunt tip. After surgical revision, with repositioning of the distal tube in the peritoneal cavity, the patient's symptoms promptly improved. When symptoms of hydrocephalus recur after successful V-P shunt placement, shunt malfunction should be suspected and evaluation for mechanical failure pursued. Catheter migration should be recognized as a correctable cause of shunt malfunction.