[Endoscopic assistance in deep lateral orbital wall decompression]

This study was conducted to develop a technique for endoscopic assistance during deep lateral orbital bone decompression.

The study included 349 patients (603 orbits) with thyroid-associated ophthalmopathy (225 women and 124 men, mean age 42.6±11.3 years) who underwent endoscopic-assisted deep lateral wall decompression (DLWD) at the M.M. Krasnov Research Institute of Eye Diseases.

Near-maximum depth of osteodestruction in the deep portion of the lateral wall (LW) of the orbit in the projection of the lateral rectus muscle was achieved in 256 patients (442 orbits). In 290 of these orbits, slight prominence of semi-transparent thinned cortical plates under the influence of the underlying dura mater (DM) was observed. In 19 cases, reaching the cortical layer of the greater wing of the sphenoid bone adjacent to the DM was indicated by the appearance of thin cortical fragments in the projection of the middle cranial fossa oriented at an acute angle to the bone defect; in 5 of these cases, cortical fragments occupied almost the entire orbital surface of the sphenoid trigone (ST). Additionally, exposure of the DM occurred in 49 cases during deep DLWD. One of the anatomical variants of the orbital vascular system found in 75 orbits was a vascular branch within the ST, which topographically corresponded to the course of the anastomosis between a. meningea media and a. lacrimalis.

The obtained results indicate the high importance of endoscopic assistance during critical stages of DLWD, particularly in hard-to-reach areas of the LW, which helps minimize the incidence of intraoperative complications.