Pseudocysts of the abdomen associated with ventriculoperitoneal shunts: a report of twelve cases and a review of the literature.

Shunt complications are reported to occur at a rate of approximately 26%. One of the less frequent but important complications is that of the pseudocyst. Since Harsh's first mention of a periumbilical cyst associated with a shunt in 1954, 44 cases have been reported in the literature. These are reviewed in addition to 12 cases of our own. From the collected series several features about the etiology and management become apparent. The most common presentation is that of abdominal distension and/or pain rather than shunt malfunction. Diagnosis is then readily made with ultrasonography. Etiologically, it is evident that an inflammatory process is a frequent predisposing factor. In our series 16% had acute infection, 41.6% had a past history of CSF infection (6 months to 6.2 years), and 16% had CNS tumor although tumor cells were not isolated from the peritoneal cysts. Our management of the cyst itself was different from that reported in other series; it was found that the cyst reabsorbed spontaneously without excision or aspiration once the CSF was diverted. The peritoneal cavity could then be used for shunting once the cyst had reabsorbed. This sometimes required conversion to an atrial or pleural shunt before reutilization of the peritoneal cavity. There were no problems with cyst recurrence despite the conversion of 58% of the shunts to ventriculoperitoneal shunts with follow-up ranging from 3 months to 4 years. The mode of management of both the cyst and the hydrocephalus is reviewed.