Interhemispheric transcallosal subchoroidal fornix-sparing craniotomy for total resection of colloid cysts of the third ventricle.

OBJECT: Endoscopic surgery has been reported to be more cost-effective and safer than open craniotomy for resection of colloid cysts, despite a 5-10% conversion rate to craniotomy, a 5% recurrence rate, a 5-10% ventricular shunting rate, a 5-10% epilepsy rate, and a 3-4 day hospital stay. In 1985, the authors developed a interhemispheric, transcallosal, subchoroidal, fornix-sparing approach that allowed safe total resection of the colloid cyst and that appeared to be superior to the endoscopic approach. The long-term results are analyzed and compared with findings in the literature.

METHODS: Fifty-seven consecutive colloid cysts were totally removed via a 3 x3-in paramedian craniotomy flap and a microscopic interhemispheric, transcallosal, subchoroidal approach sparing the ipsilateral fornix. The length of the callosotomy was 1.5-2 cm in all patients. The mean follow-up duration was 12 years (range 2-22 years). A retrospective analysis comparing the authors' results with those reported in the endoscopic literature was performed.

RESULTS: All patients had 1-year postoperative imaging studies (CT or MR imaging) documenting gross-total resection with no deaths, infection, hemiparesis, seizures, or disconnection syndrome. One surgery was complicated by bilateral subdural hematomas, which were successfully treated. There has been a zero recurrence rate. Three patients required a permanent ventriculoperitoneal shunt (including 2 who required emergency ventriculostomy before surgery). The mean hospital stay was 4.8 days (range 2-24 days). There was 1 patient with permanent short-term memory loss who presented with a herniation syndrome requiring emergency ventriculostomy.

CONCLUSIONS: The interhemispheric, transcallosal, subchoroidal, fornix-sparing approach to gross-total resection of colloid cysts is safe and led to a zero recurrence rate with no permanent neurological sequelae including epilepsy, and these results are superior to any reported results with endoscopy.