Results of surgical treatment in patients with arachnoid cysts.

A retrospective study of 35 patients operated upon for arachnoid cysts during the last 10 years was carried out. In 19 patients treated by craniotomy, membrane resection and drainage into the basal cisterns, clinical improvement could be noted in 13 cases. Correspondingly on the CT-controls the cysts were found to have disappeared in two cases and were reduced in size in seven patients. In 11 patients, however, who were initially treated by a shunting procedure, seven patients became free of symptoms. Postoperative CT-controls showed in three cases a significant reduction of the size of the cyst, which remained unchanged in two other cases. In five patients with the combination of a nonspace-occupying arachnoid cyst and subdural effusions, drainage of the latter only was sufficient to relieve the clinical symptoms. The prominent findings were the high complication rate of the primary or secondary shunting procedures (48%), as well as the close correlation between the clinical outcome and the postoperative CT-controls.