Surgical Freedom in Lacrimal Keyhole-Assisted Lateral Orbitotomy: A Radiographic Evaluation

To quantitatively compare the degrees of surgical freedom achieved by a lateral orbitotomy without bone removal versus a lacrimal keyhole-assisted approach, in which the superolateral orbital rim is shaved without full removal.

Preoperative orbital computed tomography scans from consecutive lateral orbitotomy patients (January 2023-April 2025) were retrospectively analyzed. Using Brainlab software, the authors compared the theoretical volume of surgical freedom and horizontal and vertical attack angles between a simulated orbitotomy without bone removal and the keyhole-assisted technique with incremental rim shaving (25% to 100%). Statistical analysis included paired t tests and linear regression.

Twelve patients (mean age: 52.2 years; 58% female) were evaluated. The complete keyhole-assisted approach significantly increased the volume of surgical freedom by 21% (6.2 ± 2.2 mm³ vs. 5.1 ± 2.0 mm³; p = 0.005) and the horizontal and vertical attack angles by 62% (20.4 ± 7.2° vs. 12.6 ± 4.2°; p < 0.001) and 38% (36.4 ± 9.5° vs. 26.4 ± 8.4°; p < 0.001), respectively. Partial rim shaving also yielded significant, progressive gains ( p < 0.05). Linear regression showed that each 1 mm of bone shaved improved the horizontal angle by 16%, the vertical angle by 10%, and the volume of surgical freedom by 6%. The size of the rim prominence strongly correlated with surgical freedom (r = 0.74, p = 0.02). No postoperative cosmetic or functional deficits were observed.

The lacrimal keyhole-assisted orbitotomy significantly enhances surgical freedom for orbital lesions. This minimally invasive technique offers a titratable alternative to marginotomy, allowing tailored bone removal for required maneuverability while preserving orbital rim integrity.