The Modified Anterior Temporal Lobectomy plus Amygdalohippocampectomy

Abstract

? 2012 Japanese Congress of Neurological Surgeons. All rights reserved.Objective: The authors intend to demonstrate the currently used technique of anterior temporal lobectomy plus amygdalohippocampectomy for treating refractory temporal epilepsy as developed by the lead author(HTW). The anatomy based modifications presented in this paper have been gradually added to the original technique throughout a 13-year span to make these surgeries both safer and faster. Material and methods: Three hundred and forty-six anterior temporal lobectomies plus amygdalohippocampectomies were performed by HTW from 1999 to 2011. The intraoperative observation of the difficulties encountered in each case motivated the search for modifications to overcome those difficulties. Results: The major modifications are: patient positioning with less rotation of the head and more extension of the neck, interfascial dissection of the temporalis fascia, detachment of the temporalis muscle from the angle formed by the frontal and the temporal processes of the zygomatic bone, craniotomy below the superior temporal line, a 2.5 to 3.0 cm neocortical removal with subpial ?peeling? technique, locating the temporal horn using the grey matter overlying the occipitotemporal sulcus, and resection of the amygdala based on a modified carotid-choroidal line. The modified sequence for the hippocampectomy is as follows: anterior disconnection, lateral disconnection, opening the choroidal fissure and the medial disconnection, and the posterior disconnection. Whenever possible, all the arachnoid membranes of the cisterns have to be kept intact during the intradural stage of the surgery. The overall seizure-free rate was 86%, and the complications were presented. Conclusion: The careful intraoperative observation of the procedural difficulties, the anatomy-based modifications to overcome those challenges, and extensive practice of the microsurgical techniques helped the authors to design the above described technical modifications, making medial temporal resections safer and faster.