Optimizing techniques for in-office endoscopic transnasal sphenopalatine ganglion block injections

Otolaryngologists play a central role in diagnosing and treating facial pain syndromes and headache disorders. Although sphenopalatine ganglion block is a recognized treatment option, literature on transnasal injection techniques is limited. This study's objective is to refine anatomic landmarks and optimize a technique for in-office transnasal sphenopalatine ganglion blocks. Eight cadaveric head specimens were dissected to record 16 measurements of critical anatomic landmarks and surgical instruments for sphenopalatine ganglion block. On average, the sphenopalatine foramen center was 5.94 mm (±1.65 mm) superior to the inferior border of the middle turbinate's basal lamella attachment to the lateral nasal wall. We describe the reliability of using a 20G spinal needle bent at 70-degree to perform a transnasal injection technique for sphenopalatine ganglion block. The inferior border of the middle turbinate basal lamella attachment to the lateral nasal wall may be used as an intranasal landmark in transnasal injection of the sphenopalatine ganglion. Further testing in the clinical setting is required to assess efficacy.