Transantral Approach to the Lateral Orbit

Abstract

Objective: Depending on the type of pathology and location, various methods of access have been developed to overcome the obstacle of accessing the orbit. The endoscope provides minimally invasive surgical access to the medial and inferior orbit. Expanding endoscopic access to the lateral orbit transantrally could create a minimally invasive corridor. Method: Using late injected cadavers, endoscopic dissections of the infero-lateral orbit were undertaken. A sublabial transmaxillary ostomy was created and an endoscope was advanced into the sinus. The contents of the orbit were dissected laterally to the inferior optic nerve. Photographic evidence was obtained for review. Results: A 45° endoscope was required to adequately visualize the anatomy. The perpendicular nature of the corridor necessitated the use of angled instrumentation. This also created a challenge as the dissections were completed superiorly. Dissection was found to be facile until revealing the lateral rectus muscle. Proceeding superiorly past this point was limited by the length of the instruments. Tools of dissection with greater length could possibly overcome this limitation. Overall the transantral endoscopic approach to the orbit provided an adequate surgical window inferiorly and to a limited extent laterally. The relevant anatomy was identified without difficulty. Conclusion: An endoscopic transantral approach to the infero-lateral orbit is anatomically feasible. The morbidity associated with an open approach could possibly be avoided, improving patient outcomes. Further understanding of the endoscopic anatomy of the orbit can allow for advances in surgery with improved safety and efficacy.