Proximal catheter obstruction

What it is

Proximal catheter obstruction is a blockage of the proximal (ventricular) catheter — the part of the shunt placed in a ventricle. It is the most common single cause of shunt failure.

Understanding Proximal catheter obstruction

The ventricular catheter has small holes through which CSF enters the shunt, and these can become blocked over time — for example, by choroid plexus tissue growing into the holes, by debris, or by cells and protein. When the proximal catheter is obstructed, CSF can no longer enter the shunt properly, causing a malfunction with a return of raised-pressure symptoms. Estimates often place proximal catheter obstruction as the leading cause of shunt failure (a notable share of malfunctions). It is treated by replacing the obstructed catheter during a shunt revision, sometimes with techniques to remove or bypass the blockage. Understanding this helps explain why this part of the shunt is a frequent source of problems.

Why it matters

Understanding proximal catheter obstruction helps families see why the ventricular catheter is the most frequent source of shunt failure, and why replacing it during a revision restores function.