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.

To determine the quality of survival for children with posterior fossa tumors, comprehensive neuropsychological, behavioral, and academic assessment and physician ratings of functional status were obtained on 15 brain tumor patients (ages 6-19 years) at a median of 20 months post-diagnosis. More than 50% of the children (whether irradiated or not) experienced major problems in academic, motor, sensory, cognitive, and emotional function. All but two children were reported by teachers to be "slow workers," and four of 15 patients were able to maintain their school work in regular classes. Although 80% of the patients were rated by physicians as having "excellent" or "good" functional status, no relationship was found between these global ratings and psychometric measures. Although the affected site was the posterior fossa, deficits also involved higher cortical function. These findings indicate the need for further evaluation of treatment effects and the provision of intervention for survivors.

A series of 16 patients with chronic or subacute subdural hematomas treated with continuous external drainage of the subdural space is reviewed. Of these only 44% went on to require subdural-peritoneal shunt placement. There were no complications in treatment and no clinical or laboratory evidence of infection in any case. The outcome, measured by neurological examination, was not different between the shunted and nonshunted groups. In conclusion, continuous external drainage of the subdural space in chronic and subacute hematomas of infancy frequently is an effective, definitive treatment. This approach should be considered as the initial procedure prior to subdural-peritoneal shunting.