Transsylvian functional hemispherectomy.

OBJECTIVE: To describe the technique of transsylvian-transventricular functional hemispherectomy developed at our institution.

METHODS: We review appropriate patient selection and evaluation, timing of surgery, selection of surgical approach, preoperative preparation, details of operative procedure, and postoperative management.

CONCLUSIONS: The transsylvian "keyhole" functional hemispherectomy technique involves a smaller craniotomy than other functional hemispherectomy techniques and consists of transsylvian exposure, resection of mesial temporal structures, transventricular frontobasal disconnection, callosotomy, and occipitoparietal disconnection. The key advantages of this approach compared to the Rasmussen's "classic" functional hemispherectomy are smaller exposure, shorter operative time, and lower blood loss. The efficacy of functional hemispherectomy procedures in achieving seizure freedom appears to be at least as good compared to resective procedures. The long-term complication rate will require longer follow-up times.