Selective amygdalohippocampectomy: which route is the best? An experimental study in 80 human cerebral hemispheres

Four different approach routes have been used to perform the selective amygdalohippocampectomy for the surgical treatment of epilepsy: transcortical through the middle T2 gyrus [1], translyvian through the deep sylvian fissure, transcortical subpial through the anterior T1 gyrus [2] and transcortical through the first temporal sulcus [3]. The choice between them, based on the advantages and disadvantages of each one, depends upon the different view angles they allow, and the parenchymal and vascular relationships they involve. This requires accurate knowledge of the microsurgical anatomy of this region and its features along the different acceding routes. The authors made an experimental study on 80 adult cerebral hemispheres they randomly submitted to selective amygdalohippocampectomy through these four alternative approach routes. They measured the dimensions of the major temporal limbic structures, namely the amygdala and the hippocampus, and their distances from the brain convexity and the deep sylvian fissure along those acceding routes; they also registered the main distinct microsurgical features of each. The results emerge as anatomical guidelines useful to decide for each case which way is preferable to make amygdalohippocampectomy complete, safer and easier.