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 for adult patients with hydrocephalus caused by primary aqueductal stenosis. METHODS: Eighteen of 64 patients who underwent endoscopic third ventriculostomies (ETVs) between lune 1991 and July 1995 were treated because of primary aqueductal stenosis. All of these patients accepted follow-up investigations, which were performed 3 months to 5 years after surgery. If hydrocephalic symptoms persisted, the patency of the ventriculostomy was investigated; in cases of open ventriculostomies, the patients were offered shunt surgery. 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 demonstrated temporary improvements. The ventriculostomies were patent in all nine patients who experienced less than excellent results. Subsequent ventriculoperitoneal shunt placement produced improvements for all seven patients who accepted the surgery. CONCLUSION: In our experience, the long-term effectiveness of ETVs for adult patients with noncommunicating hydrocephalus was sufficient in only 50% of the cases. One-third of the patients exhibited temporary improvements, lasting 1 to 12 months (average duration, 5 mo) after the ETVs, and then demonstrated deterioration to even worse clinical conditions, despite patent ventriculostomies. All patients who did not exhibit permanent improvements after the ETVs benefited from shunt surgery. Efforts should be made to establish methods for the selection of patients for ETV or ventriculoperitoneal shunt surgery.