Retrolabyrinthine presigmoid transpetrosal approach for selective subtemporal amygdalohippocampectomy.

The retrolabyrinthine presigmoid transpetrosal approach is a modification of the subtemporal approach which is suitable for complete amygdalectomy. By drilling away the retrolabyrinthine presigmoid petrosal bone, at least 1 cm more space below and 1 cm more space medially is obtained than in the subtemporal approach, and temporal retraction pressure is diminished when approaching from below. Operative results according to the Engel's classification of seizure control, and pre- and postoperative Wechsler Adult Intelligence Scale (WAIS), revised WAIS, and Wechsler Intelligence Scale for Children scores were measured in 16 patients treated by normal or modified subtemporal amygdalohippocampectomy. Postoperative follow-up ranged from 8 to 79 months. There has been no morbidity or mortality among these 16 patients, and postoperative seizure frequency has been diminished to less than 10% of the preoperative level in 15 of the 16. In eight patients, seizures have been eliminated totally. Subtemporal amygdalohippocampectomy achieved significantly increased performance and full scale intelligence quotient within 2 months after surgery, compared to preoperative levels. Subtemporal amygdalohippocampectomy is an alternative to the transsylvian approach, but is less invasive.