Endoscopic anatomy of the postganglionic pterygopalatine innervation of the posterolateral nasal mucosa.

Background: Recent anatomic dissections have redefined the sinonasal parasympathetic pathway suggesting that individual rami project from the pterygopalatine ganglion (PPG) to innervate the nasal mucosa via multiple small nerve fascicles. The purpose of this study is correlate these anatomic descriptions with endoscopic findings and to define the pattern and location of the posterolateral neurovascular rami.

Methods: Eight cadaver heads were utilized for a total of 16 individual sides. A lateral nasal submucosal flap was elevated while preserving all neurovascular bundles perforating the palatine bone. All nerves were traced proximally to confirm their origin.

Results: Excluding the sphenopalatine foraminal contents, accessory posterolateral nerves were noted in 87.5% (14/16) of specimens, 50% (7/14) of which contained greater than one. All nerves could be traced directly to the PPG or greater palatine nerve. Of the 25 accessory nerves identified, the most common location was posterosuperior to the horizontal attachment of the inferior turbinate (40%, 10/25).

Conclusion: This study supports prior work suggesting that neurons project from the PPG via multiple individual postganglionic rami to supply the nasal mucosa. This new anatomic insight may be exploited to selectively lesion these nerve fascicles in patients with vasomotor rhinitis to improve outcomes while avoiding the morbidities associated with vidian neurectomy.