A Radiographic Morphometric Analysis for the Preoperative Localization of the Sphenopalatine Artery

The sphenopalatine foramen (SPF) is a crucial anatomical landmark in major anterior skullbase procedures and in challenging situations, the traditional method of identification of the crista ethmoidalis may be inadequate or impossible. This study aimed to evaluate different radiological bony landmarks to assist endoscopic localization of the SPF. This was a cross sectional study which was done using computed tomography (CT) of the paranasal sinuses of 50 patients who presented to a tertiary care hospital with a history of recurrent posterior epistaxis. The distances from the SPF to the following surgical landmarks were measured from each side: nasal floor, choanal arch, maxillary line, anterior head of the middle turbinate, and the basal lamella of the middle turbinate. The mean (SD) SPF was 23.6 ± 4.6 mm above the nasal floor, as measured in the vertical dimension. In the anteroposterior dimension, the mean (SD) SPF measured 36.3 ± 2.3 mm deep to the maxillary line, 34.8 ± 3.1 mm deep to the anterior head of the middle turbinate, 7.5 ± 2.0 mm deep to the level of the basal lamella, and 9.0 ± 1.8 mm anterior to the choanal arch. This study found that the mean distances were almost the same in male and female patients. This study concluded that radiological measurements from the SPF to nasal floor, choanal arch, maxillary line, anterior head of middle turbinate and basal lamella are reliable for both sexes. Measurements from the choanal arch and basal lamella of the middle turbinate were reliable landmarks for finding the SPF. Hence, addition of above surgical bony landmarks has potential clinical application in rapid localization of the SPF.