Pediatric peri-insular hemispherotomy and functional hemispherectomy for severe medically refractory epilepsy: comparison of two techniques

•The peri-insular hemispherotomy is a highly effective treatment for medically refractory epilepsy.•It consists of a removal of the frontotemporoparietal operculum, insula and underlying deep structures.•In comparison with the functional technique, it has a shorter surgical time, a low complication rate and a wider corridor. Since it was first described in the 1970s, functional hemispherotomy has been an essential tool in treating disabling, medically refractory epilepsy resulting from diffuse unilateral hemispheric disease. We report our experience with 23 patients who underwent hemispherotomy, both using the functional hemispherotomy (FH) as well as a modified peri-insular hemispherotomy (PIH) technique. We present the surgical technique for the latter, review outcomes following disconnection surgery and discuss the differences between the techniques when it comes to complications and postoperative results. A retrospective study of 23 patients with refractory seizures who underwent cerebral hemispherectomy. A thorough analysis of the clinical, imaging, surgical features and postoperative results was performed. We also present the surgical technique for a modified PIH technique. Between 2000 and 2020, 23 pediatric patients with refractory seizures underwent hemispherotomy (12 FHs, 11 modified PIHs). 91.3% of patients were seizure free at 6 months, 87% at 1 year, and 78.3% at last follow-up. None of the 23 patients presented Engel IV outcome. FH was found to have statistically longer surgical duration (5 ± 1.5 vs. 3.83 ± 0.5 h; p =