A Comparative Surgical Analysis of Surgical Access to the Sellar and Perisellar Regions between the Frontotemporal-Orbitozygomatic Approach with Periclinoid Exposure of the Cavernous Sinus and the Endoscopic Transorbital Approach

Background: A number of studies have sought to quantitatively compare the traditional open anterolateral skull base approaches with the endoscopic transorbital approach. However, these comparisons have been generally limited to the area of exposure provided by the bone opening and trajectory and fail to account for the main avenues of exposure provided by subsequent requisite surgical maneuvers. We compare the surgical exposure and freedom around key structures in the middle cranial fossa provided by the frontotemporal-orbitozygomatic (FTOZ) and the superior eyelid endoscopic transorbital approaches, and discuss clinical scenarios amenable to each approach.

Methods: Eight FTOZ and 8 transorbital approaches were performed with subsequent applicable surgical maneuvers on 8 cadaveric heads (16 sides). In the FTOZ approach, extradural maneuvers included cutting of the meningo-orbital band, anterior clinoidectomy, unroofing of the optic canal, opening of the superior orbital fissure, displacement of the extra-annular structures, cutting of the distal dural ring, and interdural dissection. In the transorbital approach, extradural maneuvers included cutting of the meningo-orbital band, interdural dissection, anterior clinoidectomy, and displacement of the extra-annular structures. The length of exposure of cranial nerves II–V, length of the exposed segments of the ICA, surgical area of exposure of the lateral wall of the cavernous sinus, and respective angles of attack to a common target area were measured and compared using neuronavigation.

Results: As shown through the morphometric analysis, the FTOZ approach provided extradural access to the lateral, posterior, and anterior compartments of the cavernous sinus after removal of the anterior clinoid—including the carotid cave—as well as the intradural corridor through the roof of the cavernous sinus medially to the oculomotor nerve with excellent visualization of the medial compartments. The transorbital approach provided partial access to the lateral compartment. Temporal lobe retraction was more significant in the transorbital approach. Insufficient application of surgical maneuvers negate access to the cavernous sinus in both approaches.

Conclusion: This is the first study to quantitatively identify the relative advantages of the FTOZ and transorbital approaches at the target region following requisite surgical maneuvers. Understanding of this data will aid in selecting an optimal approach and maneuver set based on target lesion size and location.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
05 February 2024