Sublabial and Endonasal Multicorridor Approaches to the Anterior Orbit: An Anatomic Cross-Sectional Study and Clinical Application.

BACKGROUND AND

OBJECTIVES

The endoscopic endonasal approach offers advantages for accessing lesions in the medial and inferior regions of the orbit; however, its feasibility and practical utility in accessing the anterior orbital region remain unclear. To evaluate the 3-dimensional feasibility and maneuverability of accessing the anterior orbit using sublabial and endonasal multicorridor approaches through anatomic study.

METHODS

A total of 18 sides from 9 anatomic specimens were used for evaluation through the endoscopic endonasal ipsilateral and contralateral transethmoidal approach, endoscopic modified medial maxillectomy, and sublabial transmaxillary approach. Staged coronal cross-sections were created from the lacrimal hamulus in the anterior-to-posterior direction. The accessible ranges in the superior, inferior, and central directions from each corridor were measured and analyzed.

RESULTS

The contralateral transethmoidal corridor provided significantly broader central access than the ipsilateral side, with expanded ranges of 8.9 mm (95% CI, 2.5-15.2; P = .001) and 15.6 mm (95% CI, 9.4-21.7; P < .001) at 10 and 20 mm posterior to the hamulus, respectively. Nasolacrimal duct mobilization through the endoscopic modified medial maxillectomy technique consistently expanded access in the ipsilateral transethmoidal corridor (9.6 mm at 10 mm [P < .001]; 12.7 mm at 20 mm [P < .001]), whereas its benefit in the contralateral corridor was limited to the anterior region only (11.0 mm at 10 mm [P < .001]) and was not significant at more posterior sections. The sublabial transmaxillary approach offered superior access only in the inferior direction and only in the most anterior region.

CONCLUSION

Lacrimal hamulus serves as a reliable bony landmark for the anterior orbital region. The transethmoidal approach benefited significantly from nasolacrimal duct mobilization, with the greatest impact observed in the anterior orbital region on the ipsilateral side. Three-dimensional understanding of the accessibility enables the selection of the optimal surgical approach to this challenging region.