The Learning Curve of Cavernous Sinus Surgery: Illustrated by Symptomatic Intra-cavernous Aneurysm Clipping Through Pre-temporal Trans-cavernous Approach

Introduction: Controlling the cavernous sinus (CS) bleeding during surgery has become effective and easy with the understanding of skull base anatomy and the application of suitable topic hemostatic agents. To present the learning curve of the CS surgery via the pre-temporal trans-cavernous (PTTC) approach, surgical procedures were examined and illustrated in the surgical treatment of symptomatic intra-cavernous aneurysms.

Methods: From January to June 2021, four patients with symptomatic intra-cavernous aneurysms, who underwent the PTTC approach in our institute were reviewed and served as demonstrative cases. The authors also proposed a classification scheme for the surgical difficulties of the pathologies involving the CS via this approach.

Results: Surgical steps were described and illustrated along with videos. Four levels of surgical difficulty are: Level 1, a basic Dolenc extradural approach, which involves opening the anterior third of the superior and lateral CS walls. In Level 2, mobilizing the internal carotid artery (ICA) and opening the proximal dural ring are the key steps to enter the CS roof and deal with the lesions around the clinoid and upper-cavernous ICA. In Level 3, opening the entire aspects of the superior and lateral CS walls is the goal, which includes opening the oculomotor triangle and peeling the lateral wall of the CS to the tentorial incisura. In Level 4, mobilizing the CN3, 4, and V1 to enter the supra-/infra-trochlear triangles is the key to have the proximal ICA control. Opening the posterior CS wall is the last step to get access to the posterior fossa.

Conclusion : In treating CS pathologies, the PTTC approach serves as an effective workhorse with minimal morbidity and high success rates of gross total resection when performed by experienced skull base surgeons.