Anatomicosurgical References for Endoscopic Localization of Sphenopalatine Foramen: A Cadaveric Study

Abstract

Introduction:In patients with posterior epistaxis, generally the source of bleeding is branches of sphenopalatine artery (SPA), which enter the nasal cavity through the sphenopalatine foramen (SPF). Cases of intractable massive bleeding may require endonasal endoscopic occlusion of these vessels. Materials and methods:A total of 32 hemisections of formalinfixed cadaveric heads were used. The anatomic variations of SPF, its distance from anatomical landmarks, and angle of elevation of endoscope were studied so as to facilitate accurate localization of the foramen and endoscopic arterial ligation. Results:The SPF was generally single; however, multiple exits in the form of accessory foramina were found in 36.75% hemisections. The transition of superior and middle meatuses was the most common location of SPF, followed by the superior meatus, and middle meatus was the least common site. The accessory foramina were commonly present in the superior meatus. Ethmoid crest was distinctly visible in all but two cases. In majority of the cases, the SPF was located within a range of 55 to 65 mm from the anterior nasal spine (ANS); 60 to 70 mm from piriform aperture, 50 to 60 mm from limen nasi, 20.1 to 25 mm vertically above the floor of nasal cavity, and 8 to 15 mm from the inferior turbinate (IT). The angulation of SPF from the floor of nasal cavity was 20 to 30°. Conclusion:Exploration of lateral nasal wall (LNW) up to middle meatus would minimize the risk of missing any arterial branch, and the data of distance from the anatomical references would assist in more precise localization of SPF during endoscopic ligation or cauterization of the branches of the SPA.