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Gradual formation of an operative corridor by balloon dilation for resection of subependymal giant cell astrocytomas in children with tuberous sclerosis: specialized minimal access technique of balloon dilation.

BACKGROUND
Major sources of morbidity and mortality in patients with tuberous sclerosis who develop subependymal giant cell astrocytomas (SEGAs) relate to tumor growth and resultant hydrocephalus. We describe a modification of a specialized minimal access resection technique in which an operative corridor is formed with balloon dilation over the course of a week prior to tumor resection.


METHODS
Three patients with tuberous sclerosis who had an enlarging SEGA and concomitant hydrocephalus underwent surgical resection with this modified technique. A frontal craniotomy was performed and the optimal trajectory for tumor resection was confirmed by image guidance. After initial insertion of the deflated balloon into the ventricle and removal of the peel-away sheath, inflation of the balloon with a 1-mL saline injection sealed the tract. Additional 1-mL saline injections were continued during the next week until the balloon reached a 15-mm diameter, thus creating the operative corridor. One week after the first operation, the balloon was deflated and removed, and the patient underwent tumor resection via the newly formed operative corridor.


RESULTS
Three patients with tuberous sclerosis underwent gross total resections of SEGAs and experienced subsequent resolution of ventricular dilation. Postoperative imaging confirmed minimal cortical disruption.


CONCLUSIONS
Use of balloon dilation for the gradual formation of an operative corridor eliminated the need for additional retraction during SEGA resection, potentially decreasing injury to the surrounding neural tissue. In our three patients, the dilation tract retained its integrity during the operation and had sealed completely on postoperative imaging.