Ventriculoperitoneal (VP) shunt placement is one of the most commonly performed procedures in neurosurgery. One rare complication is the formation of an abdominal pseudocyst, which can cause shunt malfunction. It may happen due to inflammatory process, ranging from an infectious cause or to a hypersensitivity reaction to the composition of the shunt catheter, leading to malabsorption of CSF.

Abdominal pseudocyst (APC) formation is a rare complication with reports in literature varying from 0.25% to 10%. Pseudocysts are usually found in the pediatric population, which may be due to the increased incidence of hydrocephalus in children. Some are benign and cause no symptoms whereas some can result in significant abdominal pain and even malfunction of the shunt system.

With regard to abdominal pseudocysts, the presentation can be more variable. Abdominal pain is often the chief complaint in most patients, accompanied by nausea and vomiting, there may be absence of neurological signs.

The diagnosis of pseudocysts may be made by abdomen ultrasound and is most accurately made by a contrast CT scan of the abdomen.

Treatment of pseudocysts is highly variable and the method of treatment should be tailored to the overall clinical picture. Treatment options include percutaneous drainage of the pseudocyst with distal repositioning of peritoneal catheter (open or laparoscopic), placement of distal catheter in an alternative location such as the contralateral abdomen, the pleural space or the right atrium.