Outcome of endoscopic third ventriculostomy. Results from an unselected series with noncommunicating hydrocephalus

Endoscopic third ventriculostomy (ETV) has gained acceptance as the treatment of choice for noncommunicating hydrocephalus despite a relatively high failure rate and a higher surgical risk than the placement of a shunt. The benefits of shunt independence overcome both drawbacks. This argument also serves to consider candidates for ETV patients with a poor chance of success, a fact which may to a certain degree explain failure rates higher than 20% in most unselected series of patients with noncommunicating hydrocephalus.

From 1997 to 2003 sixty-six patients with suspected noncommunicating hydrocephalus were treated with ETV. Male and female patients were equally distributed. It is an adult-based series (median age 53 years). The etiology of hydrocephalus was a space-occupying lesion in 39 patients (59%) and primary aqueductal stenosis in 27 (41%). Forty-seven patients presented an acute form of hydrocephalus (71%), the remainder presented a chronic form of hydrocephalus. The morbidity and outcome of the procedure were reviewed. Criteria for success was shunt independence and failure was considered when any surgical manoeuvre was further required for the treatment of hydrocephalus. The outcome was evaluated using the Kaplan-Meier survival method.

The probability of remaining with a functioning ETV at 5.7 years (mean follow-up period) is 71.6% (95% confidence interval: 60.5-82.8). Failure occurred in 18 patients (27.3%). If failure occurs, there is a cumulative probability of 90% (95% confidence interval: 84-97) that the failure declares itself during the first 16 days after surgery. There were transient complications in five patients (7.5%), permanent in one (1.5%) and no mortality related to the procedure.

ETV had a 5-year success rate of 71.6% with a low rate of permanent complications. When ETV is successful, the result tends to hold up over time. Delayed failure is a rare event.