Cavernomas and Arteriovenous Malformations in the Mesial Temporal Region: Microsurgical Anatomy and Approaches.

BACKGROUND: The mesial temporal region (MTR) is located deep in the temporal lobe and it is surrounded by important vascular and nervous structures that should be preserved during surgery. OBJECTIVE: To describe microsurgical anatomy and approaches to the MTR in relation to cavernomas and arteriovenous malformations (AVMs). METHODS: Five formalin-fixed and red silicone-embedded heads of adult cadavers were used for this study. Between January 2003 and June 2014, 7 patients with cavernomas and 6 patients with AVMs in the MTR underwent surgery. RESULTS: The MTR of the cadavers was divided into 3 areas: anterior, middle, and posterior. Of the 7 patients with MTR cavernomas, 4 were located anteriorly, 2 were located medially, and 1 was located posteriorly. Of the 6 patients with MTR AVMs, 3 were located in the anterior sector, 2 in the middle sector, and 1 in the posterior sector. For the anterior portion of the MTR, a transsylvian-transinsular approach was used; for the middle portion of the MTR, a transtemporal approach was used (anterior temporal lobectomy); and for the posterior portion of the MTR, a supracerebellar-transtentorial approach was used. CONCLUSION: Dividing the MTR into 3 regions allows us to adapt the approach to lesion location. Thus, the anterior sector can be approached via the sylvian fissure, the middle sector can be approached transtemporally, and the posterior sector can be approached via the supracerebellar approach.