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

Objective: This study aims to elucidate the indications and technical intricacies of orbital rim removal (ORR) within the endoscopic transorbital approach (ETOA). Additionally, it seeks to conduct a comparative analysis between cases utilizing ORR and a control group to discern the associated clinical outcomes.

Methods: The study included consecutive patients who underwent ETOA between August 2016 and October 2023 in a single center. The anatomical exploration, involving three cadaveric specimens and a bony model, employs three-dimensional photogrammetry methodology to precisely showcase the ORR technique and key landmarks. Furthermore, our study introduced a novel anatomical demarcation—the “spheno-arcuate line” (SpAL)—which can serve as valuable metrics for surgical planning.

Results: A total of 121 patients were included. Pathological diagnoses included 56 (46%) patients of meningioma, 28 (23%) patients of schwannoma, 4 (3%) patients of pituitary adenoma, 15 (13%) patients of other malignant tumors, and 18 (15%) patients of other benign tumors. 53 (44%) patients underwent ORR, and good outcomes (gross total and near-total resection) were achieved in 90 (74.3%) patients. No significant difference in good outcomes was observed between the ORR group (73.1%) and the non-ORR group (75.9%) (p = 0.83). The impact of ORR on surgical outcomes was significant in meningioma patients (p = 0.04) and patients with tumors exhibiting lateral extension beyond the SpAL (p = 0.03). Three-dimensional reconstructed volumes of surgical exposure using photogrammetry for ETOA revealed that the SpAL demarcated volumes significantly expanded after ORR.

Conclusion: This study establishes ORR as a pivotal advancement in ETOA, demonstrating its capacity to significantly enhance surgical outcomes, particularly in specific tumor scenarios. The anatomical study convincingly demonstrated the inclusion of ORR significantly expanded the final volume of surgical exposure during the ETOA. The combination of clinical insights and the feasibility anatomical study demonstrates ORR as a valuable tool, augmenting outcomes and expanding the surgical armamentarium for complex cases in transorbital surgery ([Figs. 1] [2] [3] [4]).

Fig. 1 Spheno-arcuate line.

Fig. 2 The three-dimensional reconstructed CT images depict extent of orbital rim removal.

Fig. 3 The three-dimensional reconstructed models generated through photogrammetry with dedicated software.

Fig. 4 The bar graphs illustrate the overall impact of orbital rim removal in extend of resection.

 

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

Publication History

Article published online:
07 February 2025