Orbital Rim Removal in Endoscopic Transorbital Approaches: Unveiling Indications and Technical Nuances

The aim of this study was to elucidate the indications and technical intricacies of orbital rim removal (ORR) within the endoscopic transorbital approach (ETOA). In addition, it seeks to conduct a comparative analysis between cases using ORR and a control group to discern the associated clinical outcomes.

The study included consecutive patients who underwent ETOA between August 2016 and October 2023 in a single center. The anatomic exploration, involving 3 cadaveric specimens, uses 3-dimensional photogrammetry methodology to precisely showcase the ORR technique. Furthermore, our study introduced a novel anatomic demarcation-the "sphenoarcuate line" (SpAL)-which can serve as valuable metrics for surgical planning.

A total of 121 patients were included. Pathological diagnoses included 56 patients (46.3%) of meningioma, 28 patients (23.1%) of schwannoma, 15 patients (12.4%) of other malignant tumors, and 22 patients (18.2%) of other benign tumors. ORR was performed in 54 patients (44.6%). Good outcomes-defined as gross total or near-total resection-were achieved in 90 patients (74.3%). No significant difference in good outcome rate was observed between the ORR group (73.1%) and the non-ORR group (75.9%; P = .83). However, ORR was associated with significantly improved good outcome rate in meningioma patients ( P = .04) and patients with tumors exhibiting lateral extension beyond the SpAL ( P = .03). 3-dimensional reconstructed volumes of surgical exposure using photogrammetry for ETOA revealed that the SpAL-demarcated volumes significantly expanded after ORR.

This study establishes ORR as a pivotal advancement in ETOA, demonstrating its capacity to significantly enhance surgical outcomes, particularly in specific tumor scenarios. The anatomic study convincingly demonstrated the inclusion of ORR significantly expanded the surgical exposure during the ETOA. The combination of clinical insights and the feasibility of anatomic study demonstrates ORR as a valuable tool, augmenting outcomes and expanding the surgical armamentarium for complex cases in transorbital surgery.