Analysis of retained ventricular shunt catheters.

To identify the causes of ventricular shunt catheter retention, 42 shunt removals in 28 patients in our neurosurgical clinic from 1982 to 1991 were analyzed. The mean patient age was 13.8 years (2 mos-78 yrs), and mean shunt duration was 20.1 months (0.5-94 mos). There were nine retained ventricular catheters, including five with obstruction of the ventricular catheter. Shunt duration was significantly longer compared with the unretained group. Three retained ventricular catheters were stained by HE for histological examination. Light microscopy showed the inner lumen of catheters filled with granulomatous connective tissue and reactive glial tissue, and giant cell reaction to silicone material. Scanning electron microscopy of two catheters found peeling on the inner surface of the catheter, evidence of aging of the material. Granulomatous connective tissue and glial tissue reaction to aged silicone are suggested as the cause of catheter retention.