Endoscopic anatomy of the sphenopalatine and posterior nasal arteries: implications for the endoscopic management of epistaxis.

BACKGROUND: Refractory posterior epistaxis is a challenge for otolaryngologists. Most algorithms for managing this condition ultimately call for interrupting the arterial blood supply to the nasal mucosa. Traditionally, this was accomplished either by transantral arterial ligation or by arteriographic-guided embolization. More recently, the endonasal endoscopic approach has also been described. Because the primary blood supply to the posterior nasal cavity is derived from the terminal branches of the sphenopalatine and the posterior nasal arteries, we conducted this anatomic study to examine and describe the anatomic relationship of these two arteries as they exit the pterygopalatine fossa and enter the nasal cavity.

METHODS: We performed endoscopic dissections of this anatomic region in nine fresh and one formalin-preserved cadaver specimens. A total of 19 sides were examined.

RESULTS: In 3 of 19 specimens (16%), the sphenopalatine artery branched from the sphenopalatine artery within the sphenopalatine canal, allowing the two arteries to exit together. In 8 of the 19 specimens (42%), the sphenopalatine artery exited much more posteriorly, yet from within a shared posteriorly elongated sphenopalatine foramen. In the remaining eight specimens (42%), the sphenopalatine artery exited through a distinct foramen directly posterior to the larger sphenopalatine foramen.

CONCLUSION: Understanding this anatomic relationship is important in performing endoscopic arterial ligation. If the sphenopalatine artery is not specifically identified and ligated, an important component of the posterior nasal circulation will not be addressed adequately by this surgical approach.