A study of the maxillary and sphenopalatine arteries in the pterygopalatine fossa and at the sphenopalatine foramen.

OBJECTIVES: Arterial ligation remains a key option in the treatment of persistent epistaxis and clarification of the arterial configuration of the distal maxillary/sphenopalatine artery is important for understanding the rationale behind current surgical treatments. Greater understanding of the arterial anatomy will reduce the risk of technical failures and improve the reliability of surgical interventions for persistent epistaxis and will also be useful for surgeries involving the pterygopalatine fossa.

STUDY DESIGN: Anatomical study in cadavers.

METHODS: This is an anatomical study of 128 cadaveric tissue blocks containing the pterygopalatine fossa. In total, 118 tissue blocks were microdissected using a Watson-Barnet dissecting microscope. Ten injected tissue blocks were cleared by the Spalteholz technique. Photographic records were made.

RESULTS: Analysis demonstrated three common configurations of the maxillary artery in the pterygopalatine fossa: a single looped form (18%) and two double-looped forms, 'E' (51%) and 'M' (31%). The maxillary artery bifurcates before the sphenopalatine foramen in 105 cases (89%). The sphenopalatine foramen lies at the posterior end of the middle turbinate; in 58% of cases it lies in both the superior and middle meati. Asymmetry in the size of the maxillary arteries was uncommon; only 3% could be described as 'dominant'.

CONCLUSIONS: The arterial configuration of the maxillary artery in the pterygopalatine fossa can be complex but may be classified into one of three forms. Some configurations may be more liable to lead to difficulties with branch identification during surgical treatment of epistaxis particularly in combination with an inadequate osteotomy. Clinicians should expect to find more than one vessel exiting the sphenopalatine foramen and actively search for these during surgery. Asymmetry in the maxillary/sphenopalatine arteries is not common and contralateral ligations are not indicated.