Surgical anatomy of the insular cortex

Objective The objective of the study was to investigate the surgical anatomy of the insular cortex, morphology and vascularization of the insula and adjacent opercula in terms of transsylvian and transcortical approaches, and identification of the permissible anatomical boundaries for resection of glial tumors of the insula. Material and methods The study was conducted on 18 anatomical specimens fixed in an alcohol-glycerol solution. Perfusion of the internal carotid artery with red latex was used to study the arterial system. Dissection of the arteries and Sylvian fissure, investigation of the morphological features of the opercula as well as simulation of the transsylvian and transcortical approaches to the insula were performed using a surgical microscope, in a certain sequence. Results In the trassylvian approach, the anteroinferior part of the insula (including the limen insulae) is the most technically easy-to-reach area, whereas the superior parts of the insula are the most difficult-to-reach areas. With the tumor localized in the superior insula, the transcortical approach may be recommended that, unlike the transsylvian approach, does not require a significant retraction of the brain matter and provides a larger surgical corridor. The transcortical approach, regardless the insular region, provides a better surgical view and workspace compared to the transsylvian approach. However, the previous approach is characterized by less access to the important anatomical landmarks such as the peri-insular sulci, limen insulae, and lateral lenticulostriate arteries. Furthermore, the approach requires dissection of the brain matter of the frontal and temporal lobes. Conclusion Detailed knowledge of the surgical anatomy of the insular region provides correct intraoperative identification of a number of the major anatomical landmarks (limen insulae, peri-insular sulci, most distal lenticulostriate artery) and facilitates choosing the proper surgical approach.