LAUSR

INTRODUCTION Distal ophthalmic artery (OpA) aneurysms are a rare subset of vascular lesions with lack of optimal treatment. The management of these aneurysms may require complete occlusion of the parent vessel, carrying a risk of permanent visual impairment due to individual variations of extracranial collateral flow to the intraorbital OpA (iOpA). OBJECTIVE This study aimed to test the feasibility of a superficial temporal artery (STA) to iOpA bypass to prevent acute ischemic retinal injury. Two different transorbital corridors (superomedial and postero-lateral approaches) for this bypass were evaluated. METHODS Each approach was carried out in 10 specimens each (n=20). The corridors were compared to achieve the optimal exposure of the iOpA until the central retinal artery (CRA) origin was visualized. An end-to-end anastomosis was performed from STA-to-iOpA. The arterial caliber and length at the anastomotic sites, required donor artery length, and intraorbital surgical area were measured. RESULTS STA-iOpA bypasses were performed in all specimens. For the posterolateral transorbital approach, the mean caliber of STA was 1.8±0.2mm, and that of iOpA was 1.7±0.5mm. The required STA graft length was 78.3±1mm with lateral iOpA transposition of 8.2±1.1mm. For the superomedial approach, the average STA length required for an intraorbital bypass was 130.8±14.0mm. The mean calibers of iOpA and STA were 1.5±0.1mm and 1.5±0.1mm, respectively. CONCLUSION This study demonstrates the feasibility of a novel revascularization technique of the iOpA using two different transorbital approaches. These techniques can be used in the management of intraorbital lesions such as OpA aneurysms, tumoral infiltrations or intraoperative injuries.