[Treatment of recurrent chronic subdural hematoma--setting an Ommaya tube]

The rate of postoperative recurrences of chronic subdural hematomas is high. Several methods have been advocated, but each one remains controversial. We proposed a simple method of setting an Ommaya tube after burr-hole evacuation. The reservoir was placed in the subcutaneous space, the tip of the tube was placed in the subdural space. The reservoir was punctured with a needle, thereby allowing aspiration of fluid from the subdural space. Sixty one cases of chronic subdural hematomas were operated by simple burr-hole evacuation. The Ommaya tube was used in 46 selected patients.: 1) the volume of hematoma was more than 100 ml and, or 2) older than 70 years of age. Reaccumulation of subdural effusion was detected in 10 cases. The subdural effusions were drained by percutaneously needling the reservoir of the Ommaya tube. This procedure was curative in 9 of the patients. However 1 patient required a small craniotomy. The patient had two outer membranes therefore inner hematoma could not be removed. The authors propose this technique and discuss about it.