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

ABSTRACT

OBJECTIVES: To verify the feasibility and to discuss advantages and disadvantages of a piezoelectric orbitotomy (PO) during Superior Eyelid Endoscopic Transorbital Approach (SETOA). METHODS: Five adult specimens underwent exoscopic/endoscopic SETOA to middle cranial fossa. The surgical corridor was created via piezoelectric orbitotomy by performing three selective and safe micrometric bone cuts providing a one-piece trapezoid bone flap which was repositioned and secured at the end of procedure. A 3D scan of the bone flap allowed us to reconstruct a 3D model and calculate its volume. An illustrative case demonstrating the application of this novel technique was also presented. RESULTS: Anatomical-morphometric quantitative analysis showed a mean bony-volume gain of 1,574.26 mm3 by using PO. PO 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 bony gap; a complete sparing of soft tissues and neurovascular structures in- and around the orbit was observed. Lateral orbital wall reconstruction by replacing the bone flap aims to mitigate the risk of enophthalmos, proptosis, CSF leakage, pseudomeningocele and pulsatile headache, which represent significant challenges in the relevant literature. CONCLUSION: PO may offer a viable, selective, effective, safe alternative to high-speed drilling during SETOA, especially for patients affected by intra-axial pathologies in which a watertight closure is mandatory. This procedure could prevent/decrease the risk of some of the main postoperative complications associated to the standard SETOA, resulting potentially in better functional and esthetic outcome.