Transorbital Transnasal Endoscopic Combined Approach to Anterior and Middle Skull Base

Background: The aim of this study is to investigate the feasibility of a combined transorbital and transnasal approach to the anterior and middle cranial fossa. Method: Cadaveric dissection of five silicon-injected heads. A total of 10 bilateral transorbital approach and 5 extended endonasal approaches were performed. Identification of the surgical landmarks, main anatomical structures, feasibility of combined approach, and reconstruction of the superior orbital defect were examined. Results: Transorbital approach showed great versatility and provides the surgeon a direct route to the anterior and middle cranial fossa. Anterior/posterior ethmoid arteries, optic nerve, and superior orbital fissure were the landmarks for the superior orbital wall craniectomy. Transorbital avascular plane showed no conflict with major nerves or vessels. Large exposure area from crista galli to the third ventricle was demonstrated with significant control of different neurovascular structures. Combined transorbital transnasal approach provides considerable value in form of extent of the exposure and the free hand movement of the two surgeons. Conclusion: Combined transorbital transnasal approach demonstrates better visualization and control of the ventral skull base and can overcome the current surgical limits of a single approach. Combination of these two minimally invasive approaches should reduce the overall morbidity. Clinical trials are needed to evaluate the virtual applications of this approach.