Hydrocele after ventriculoperitoneal shunting.

Hydroceles were noted in six patients who had ventriculoperitoneal shunts at less than 1 year of age. These took a few days to several months to develop. The incidence was 7% in girls and 23% in boys less than 1 year of age. Hydrocephalus was especially severe in the older patients in the group. In one case, the hydroceles cleared spontaneously when a peritoneal catheter was removed. A patent processus vaginalis may allow development of a hydrocele in the face of increased intra-abdominal fluid and pressure. The catheter position may be important, and it is possible that CSF alters the absorbing properties of the peritoneum and also prevents closure of the processus vaginalis.