Morphometric evaluation of the sphenopalatine foramen for endonasal surgery.

OBJECTIVE: Ligation of the sphenopalatine artery is used to treat severe nasal haemorrhage. Despite the high rates of success reported, errors and complications may occur in locating the sphenopalatine foramen (SPF) through which the vasculonervous structures penetrate the nasal cavity. Thus, the objective of this study was to investigate the numerical variation of the SPF, its relation to the ethmoid bone crista of the palatine bone in the lateral nasal wall, its distance from the anterior nasal spine and the angle between this distance and the anterior nasal floor.

DESIGN: Anatomical study.

SETTING: Regional tertiary reference center. MATERIAL AND INTERVENTIONS: Fifty-four hemiskulls were submitted to anatomical study and measurements were made on more than 12 dissected hemiskulls using the Image Tool 3.0 software.

RESULTS: The SPF was single in 87% of the specimens, and more than one orifice was present in 13%. In most specimens it was possible to establish a relation with the ethmoid crista, which is a surgical reference for the SPF location. The mean values of the measurements were significantly higher in the hemifaces than in the hemiskulls, ranging from 54 to 63 mm, and angulation ranged from 20 to 32 degrees.

CONCLUSIONS: The study demonstrated that in most specimens studied the SPF was single and located in the superior nasal meatus. The distances measured suggest that these values can be used as distance references for the use of the endoscope for ligation or endonasal cauterization of the branches of the sphenopalatine artery, preventing possible errors and complications.