Endoscopic third ventriculostomy in the management of communicating hydrocephalus: a preliminary study

Abstract

The purpose of this study was to elucidate the efficacy of endoscopic third ventriculostomy (ETV), the procedure's indications, and prognosis after treatment in patients with communicating hydrocephalus. Between August 2002 and January 2007, 32 ETVs were performed in 32 patients with communicating hydrocephalus (24 men and 8 women) at the authors' institution. The patients ranged in age from 25 to 82 years old (mean 61.4 years), and had a follow-up of 2-53 months (mean 14 months). The patients were divided into 2 groups according to the results of preoperative tests. The first group included 17 patients with idiopathic normal-pressure hydrocephalus, and the second group included 15 patients with secondary communicating hydrocephalus who experienced meningitis, spontaneous subarachnoid hemorrhage, or hypertensive intracranial hemorrhage. Both univariate and multivariate statistical analyses were performed to assess the prognostic relevance of the cause of communicating hydrocephalus, the preoperative Kiefer scale score, and hydrodynamic findings in predicting the results after ETV. Excellent results were achieved in 25% of patients, good results in 40.6%, satisfactory in 12.5%, and poor in 21.9% of patients. The authors found that the preoperative Kiefer score and the patient's age had a high correlation with overall ETV outcome. Nineteen patients (59.3%) with comparatively mild symptoms (Kiefer Score 0-10) had a favorable course after ETV. Three patients in this group showed a satisfactory course, and 1 had a poor course. Among patients with Kiefer scores of 11-21 points, 6 (46%) had a favorable course, 1 (8%) a satisfactory one, and 6 (46%) had no relief from symptoms at all. Fourteen (88%) of 16 patients < 65 years of age had a favorable course after ETV. However, only 7 of 16 patients (44%) > 65 years showed definite improvement after ETV. Among the Kiefer score indicators, the preoperative mental state played an important role in predicting ETV outcome. The results of this test imply that the relative risk of ETV failure in a patient with a concentration disorder is about 2 times that in a patient without. Of the 7 patients with secondary communicating hydrocephalus who had elevated intracranial pressure (range 205-265 mm H2O), 5 patients had a favorable result from ETV. Meanwhile, in the same group, 5 (63%) of 8 patients with normal intracranial pressure had an excellent or good result. In comparing the findings on cine MR imaging before and after surgery, there was evidence of a decrease in the velocity and quantity of cerebrospinal fluid flow in the aqueduct after ETV. The new hydrodynamic concept of hydrocephalus opens the possibility that ETV may be an effective treatment for communicating hydrocephalus. It thus constitutes an interchangeable alternative to shunting. Patient age, analysis of the causes of hydrocephalus, and mental state evaluation play important roles in outcome prediction in patients with communicating hydrocephalus who undergo ETV. Randomized clinical studies are needed to explore further the role of this treatment in communicating hydrocephalus therapy.