Anatomical Step-By-Step Dissection of the Transcavernous Approach to the Interpeduncular and Prepontine Cisterns: Surgical Anatomy of the Dorsoclival and Upper Basilar Area for Trainees

Background: The transcavernous approach (TcA) is a complex approach that provides access to the interpeduncular fossa, the prepontine cistern, and the Meckel cave region. Many descriptions of the TcA have been published, these descriptions usually either provide views that are difficult to achieve in the operating room or are written for an audience with considerable surgical knowledge and expertise. A practical, step-by-step surgical guide that allows neurosurgical trainees of different levels to easily understand this approach is needed.

Methods: Three (six sides) formalin-fixed, colored-injected specimens were prepared for bilateral dissection. The specimens were dissected under microscopic magnification. A TcA was performed and documented in a cadaveric surgical simulation video and stepwise 3D photographic images. One basilar aneurysm was selected to illustrate the surgical nuances of the technique ([Fig. 1]).

Results: The TcA provides excellent access to lesions located in the interpeduncular fossa superomedially, the prepontine cistern inferomedially, and the region of the Meckel cave laterally. A complete TcA significantly increases the working window to this deep and hidden region in the upper anterior third of the posterior fossa by opening and widening the two major triangles of the cavernous sinus roof: the clinoidal and the oculomotor triangles. After an extended pterional craniotomy with a temporal extension, key steps in the TcA included (1) an anterior clinoidectomy, (2) cutting of the proximal dural ring, (3) cutting of the distal dural ring, (4) opening of the cavernous sinus, and (5) a posterior clinoidectomy.

Conclusion: Detailed knowledge of the cavernous sinus's microsurgical anatomy has made cavernous sinus and retroclival surgery safe. We describe a comprehensive approach for learning the technical nuances of the TcA technique in a way that is intended to be understandable and usable for a junior skull base surgeon and resident audience.

Fig. 1

Publication History

Article published online:
12 February 2021