How effective is endoscopic third ventriculostomy in treating adult hydrocephalus caused by primary aqueductal stenosis?

OBJECTIVE: To evaluate the long-term efficacy of third ventriculostomies fo r adult patients with hydrocephalus caused by primary aqueductal stenosis. METHODS: Eighteen of 64 patients who underwent endoscopic third ventriculos tomies (ETVs) between lune 1991 and July 1995 were treated because of prima ry aqueductal stenosis. All of these patients accepted follow-up investigat ions, which were performed 3 months to 5 years after surgery. If hydrocepha lic symptoms persisted, the patency of the ventriculostomy was investigated ; in cases of open ventriculostomies, the patients were offered shunt surge ry. The effects of the shunt surgery were evaluated after 3 months. RESULTS: After ETV, nine of the patients exhibited excellent improvements, two exhibited slight improvements, one displayed no change, and six demonst rated temporary improvements. The ventriculostomies were patent in all nine patients who experienced less than excellent results. Subsequent ventricul operitoneal shunt placement produced improvements for all seven patients wh o accepted the surgery. CONCLUSION: In our experience, the long-term effectiveness of ETVs for adul t patients with noncommunicating hydrocephalus was sufficient in only 50% o f the cases. One-third of the patients exhibited temporary improvements, la sting 1 to 12 months (average duration, 5 mo) after the ETVs, and then demo nstrated deterioration to even worse clinical conditions, despite patent ve ntriculostomies. All patients who did not exhibit permanent improvements af ter the ETVs benefited from shunt surgery. Efforts should be made to establ ish methods for the selection of patients for ETV or ventriculoperitoneal s hunt surgery.