Microneuroanatomy of the Anterior Frontal Laser Trajectory to the Insula.

Abstract

BACKGROUND\nMRI-Guided Laser Interstitial Thermal Therapy (LITT) is an emerging minimally invasive procedure for the treatment of deep intracranial lesions. Insular lesions are challenging to treat due to the risk of damaging important surrounding structures. The precise knowledge of the neural structures that are at risk along the trajectory and during the ablation is essential to reduce associated complications.\n\n\nOBJECTIVE\nThis study aims to describe the relevant anatomy of the anterior frontal LITT trajectory to the insular region by using sectional anatomy and fiber dissection technique.\n\n\nMETHODS\nThree silicone injected cadaveric heads were used to implant laser catheters bilaterally to the insular region by using a frameless stereotactic technique from a frontal approach. Sections were cut in both in oblique axial plane parallel to the trajectory and in the coronal plane. White matter fiber dissections were used to establish the tracts related to the laser trajectory from lateral to medial and medial to lateral.\n\n\nRESULTS\nSupraorbital regions were selected as entry points. After crossing the frontal bone, the track intersected the inferior frontal lobe. The catheter was illustrated reaching the insular region medial to the inferior fronto-occipital fasciculus and insular cortex, and superior to the uncinate fasciculus. Uncinate fasciculus, extreme capsule, claustrum, external capsule and the putamen were traversed, preserving the major vascular structures.\n\n\nCONCLUSION\nIndependent of the insular area treated, an understanding of the neuroanatomy related to the anterior frontal laser trajectory is essential to improve the ability to perform LITT of this challenging region.