A Secure Approach to the Inferior Horn Using the Deep Medullary Vein as an Anatomic Guide.

Abstract

Safe entry to the inferior horn is required for a selective approach to the medial temporal region. This can be challenging sometimes for inexperienced surgeons. Our objective was to verify the usefulness of the deep medullary vein (DMV) as an intraoperative landmark for safely entering the inferior horn during the transsylvian selective approach to the mesial temporal region. Videos of 8 cases of transsylvian selective amygdalohippocampectomies performed at the University of Tokyo Hospital from 2013 to 2015 were reviewed. Consistency of the DMV and time required to open the inferior horn via the temporal stem through the inferior limiting sulcus were retrospectively evaluated. DMVs were identified in all cases; the average number identified was 2.5 ± 0.3 (mean ± SE). The inferior horn was opened without disorientation in all cases, with mean dissecting time of 7.0 minutes ± 1.1. No complications were caused by disorientation within the temporal stem white matter. Consideration of the venous system within the white matter and following the DMV could reduce the risk of disorientation and enable the surgeon to reach the inferior horn in a straightforward manner without accidental white matter damage.