Assessing the Feasibility of Selective Piezoelectric Osteotomy in Transorbital Approach to the Middle Cranial Fossa: Anatomical and Quantitative Study and Surgical Implications

Abstract

Objective

To verify the feasibility and discuss advantages and disadvantages of a piezoelectric orbitotomy during superior eyelid endoscopic transorbital approach (SETOA). An illustrative case demonstrating the application of this novel technique is also presented.

Methods

Exoscopic/endoscopic SETOA to middle cranial fossa was performed on 5 adult specimens. The surgical corridor was created via piezoelectric orbitotomy by performing 3 selective and safe micrometric bone cuts providing a 1-piece trapezoid bone flap, which was repositioned and secured at the end of the procedure. A three-dimensional scan of the bone flap allowed us to reconstruct a three-dimensional model and calculate its volume.

Results

Anatomical-morphometric quantitative analysis showed a mean bone volume gain of 1574.26 mm³ by using piezoelectric orbitotomy. Piezoelectric orbitotomy also yielded concrete surgical advantages and theoretical benefits in terms of functional and esthetic outcomes. All osteotomies were micrometric clear-cut and precise, resulting in a very thin bone gap; complete sparing of soft tissues and neurovascular structures in and around the orbit was observed. Lateral orbital wall reconstruction by replacing the bone flap was performed to mitigate the risk of enophthalmos, proptosis, cerebrospinal leakage, pseudomeningocele, and pulsatile headache, which represent significant challenges.

Conclusions

Piezoelectric orbitotomy may offer a viable, selective, effective, safe alternative to high-speed drilling during SETOA, especially for patients with intra-axial pathologies, in which a watertight closure is mandatory. This procedure could prevent or decrease the risk of some of the main postoperative complications associated with standard SETOA, potentially resulting in better functional and esthetic outcomes.