Long-term access to cystic brain stem lesions using the Ommaya reservoir: technical case report

Unresectable cystic brain stem lesions are often responsible for neurological dysfunction. Stereotactic aspiration of such lesions can lead to clinical improvement, but cyst recurrence is common and multiple aspirations may be necessary.

Three children with unresectable cystic brain stem lesions were treated at the University of Florida. Two patients initially underwent stereotactic biopsy and cystic aspiration, both improving after cystic decompression. Both patients returned 3 months later with symptomatic cyst recurrences requiring further intervention. Six years after surgical resection of a posterior fossa medulloblastoma, the third patient presented with a dorsal midbrain cyst.

All three patients had catheters placed into the cyst cavities under stereotactic guidance. A subcutaneous Ommaya reservoir was attached to the existing catheter. In the event of symptomatic cyst recurrence, the Ommaya reservoir can be tapped in an outpatient setting.

Cystic decompression resulted in clinical improvement in all three children. Multiple aspirations were necessary in two patients for symptomatic cyst recurrences. The Ommaya reservoir allows for cyst aspiration in an outpatient setting and avoids multiple stereotactic manipulations. This system may also be used to instill radioisotopes or it may be converted to a cyst-peritoneal shunt if multiple aspirations fail to achieve cystic control.