Abdominal pseudocyst

What it is

An abdominal (CSF) pseudocyst is a walled-off pocket of fluid that can form around the tip of a ventriculoperitoneal (VP) shunt's distal catheter in the abdomen. It can cause shunt malfunction (by impairing drainage) and abdominal symptoms.

Understanding Abdominal pseudocyst

Sometimes the area around the distal catheter tip in the abdomen becomes walled off by inflammation or scarring, trapping the draining CSF in a pocket (a pseudocyst). This impairs the absorption of CSF, leading to a shunt malfunction, and can cause abdominal symptoms such as pain, swelling, or a mass. Abdominal pseudocysts are sometimes associated with prior infection or inflammation. They are identified with abdominal imaging (such as ultrasound or CT) and treated by addressing the cyst — draining it and repositioning or revising the distal catheter to a new location, along with treating any infection. Understanding pseudocysts helps explain one way the abdominal end of a VP shunt can cause problems.

Why it matters

Understanding abdominal pseudocyst helps families see how a fluid pocket can form around the shunt's abdominal end, causing malfunction and abdominal symptoms, and how it is identified and treated.