Transsylvian transopercular peri-central core hemispherotomy for treating epilepsy: anatomy, surgical technique, and clinical outcome.

Objective: The objective of this study was to display the anatomical landmarks, surgical technique, and clinical outcome of transsylvian transopercular peri-central core hemispherotomy (TTPH) for treating refractory epilepsy.

Methods: From 2011 to 2023, 26 patients (12 with Rasmussen syndrome, 8 with hemimegalencephaly/cortical malformations, and 6 with hypoxic-ischemic encephalopathy; mean [range] age 11.3 years [16 months to 35 years]; 13 females; and 13 with right-side pathology) underwent TTPH. The mean (range) follow-up was 88 (14-156) months. The intradural surgical time, use and amount of blood transfusion, postoperative fever, hospital stay, weight at surgery, and seizure onset to surgery interval are reported.

Results: TTPH consists of 1) sylvian fissure opening, 2) coagulation of the M2 and M3 branches, 3) frontoparietal opercula removal, 4) suprainsular resection, 5) insula removal, 6) selective amygdalohippocampectomy, 7) disconnection of the posterior temporal and occipital lobes using the tentorium and falx as landmarks, 8) intraventricular callosotomy, and 9) disconnection of the basal frontal lobe. In cortical malformation, the gray-white matter interface serves as a landmark. The average intradural operating time was 7 hours 18 minutes (3 hours 33 minutes to 13 hours 45 minutes); all patients were Engel class I; and 2 patients presented with procedure-related complications (meningitis and transient abducens nerve palsy). No patient required shunt surgery or reoperation.

Conclusions: TTPH offers anatomical landmarks as intraoperative guides and has achieved good seizure control and low complication rates.