THE SUPRACAROTID-INFRAFRONTAL APPROACH

Abstract

Many symptomatic cavernous malformations deep in the anteroinferior basal ganglia are deemed to be inoperable and managed conservatively because transcortical, transsylvian-transinsular, and transcallosal approaches are unsuitable. We present an approach to these lesions through the supracarotid triangle, between ascending perforators, and through the basomedial frontal lobe. The supracarotid-infrafrontal approach incorporates an orbitozygomatic craniotomy, wide microsurgical exposure of the supracarotid triangle, dissection of perforating arteries, and image-guided resection through the posterior part of the medial orbital gyrus and anterior perforated substance. During 10 years of surgical experience with 269 patients with cavernous malformations, 5 patients were identified with lesions in the basal ganglia that were resected completely using the supracarotid-infrafrontal approach. Transient neurological deficits were observed postoperatively in 2 patients, and all patients had excellent outcomes (modified Rankin Scale score of 0 or 1; mean duration of follow-up, 1.4 years). Cavernous malformations in the anteroinferior basal ganglia come to the brain surface directly behind the internal carotid artery bifurcation, and the supracarotid-infrafrontal trajectory best matches the lesions' axes. The surgical corridor runs between perforating arteries, but entrance into these lesions opens additional working space that is not normally present when the approach is used with aneurysms. Careful handling of crossing and ascending perforating arteries is critical, as is delicate dissection of the lesion's superior pole where it abuts the internal capsule.