Endoscopic Transorbital Transconjunctival Approach to the Pterygopalatine Fossa

This study aimed to anatomically define the endoscopic transorbital(ETO)transconjunctival approach to access the pterygopalatine fossa(PPF).MethodsThis study was conducted using 5 formalin-fixed,silicone-injected humancadaver heads at the Bahçes¸ehir University Faculty of Medicine Rhoton Anatomy Laboratory.A total of 10 PPFs on both orbits of these cadavers wereexamined using the ETO transconjunctival approach.Endoscopic dissectionswere performed using a 0-degree Olympus endoscope,recorded with a fiberopticcable, light source,camera system,and a digital video recording system.ResultsThe surgical technique consisted of three steps:1.Orbital Conjunctival Stage:Anincision was made in the infraorbital region through a transconjunctivalapproach,followed by subperiosteal dissection extending posteriorly.2.Orbitomaxillary Stage:Osteotomy was performed with posterior compression on theinfraorbital floor, revealing the orbitomaxillary segment of the infraorbitalnerve(ION) and allowing entry into the maxillary sinus.3.Pterygopalatine Stage:The posterior maxillary wall was removed, exposing the PPF.The pterygopalatine segment of the ION was revealed,and other anatomical structures inthe region were identified.The distance from the inferior orbital rim to the distalend of the infraorbital canal(surface to depth) was measured as an average of21.8 ± 1.6mm.The course of the ION branch and CN V2 from the inferior orbitalrim to the foramen rotundum(FR)was calculated as an average of 47.3 ± 4.4mm.The minimum amount of posterior maxillary wall that needed to be removed toaccess the ION transitioning to CN V2 within the PPF was recorded as 12.7 ±3.5mm vertically and 11.9 ± 1.5mm horizontally(Table 1).ConclusionsThe ETO transconjunctival method has been shown to be an alternativeapproach to other techniques in selected cases for accessing the PPF.Its majoradvantages include a lower risk of complications and a more straightforwardapproach compared to other methods.Due to the limited number of anatomicaland clinical studies in the literature on this topic,there is a particular need fornew and extensive anatomical cadaver series.