The Pterygopalatine Ganglion Within the Pterygopalatine Fossa: Quantitative Topography and Implications for Posteriorly Directed Percutaneous Access

Abstract

A detailed understanding of the anatomy of the pterygopalatine fossa (PPF) is essential for performing radiofrequency, anesthetic blockade, and neuromodulation procedures targeting the pterygopalatine ganglion (PPG). This study aimed to characterize the spatial relationships among the PPG, the walls of the PPF, and the maxillary artery and its branches, and to identify safer access pathways. Twenty-two PPFs from 11 adult human cadaveric heads were dissected. Precise morphometric measurements of the PPG and surrounding neurovascular structures were obtained, with particular emphasis on their relationships to the PPF walls. The PPG was consistently located near the posterior wall [0.8 mm (0.6-1.1)] and the superior wall [1.4 mm (1.0-1.9)], and at progressively greater distances from the medial [2.1 mm (1.8-2.7)] and anterior walls [2.7 mm (1.7-3.1)]. The maxillary artery and its main branches occupied the anterior half of the PPF and were closely related to the anterior wall. In most specimens, the pharyngeal and Vidian arteries coursed anteroposteriorly within the fossa, frequently in close relationship with the PPG. Consistent with previous anatomical descriptions, the PPF comprises an anterior predominantly vascular compartment and a posterior predominantly neural compartment. In the present study, the posterior compartment consistently contained the PPG in a superomedial position and, in most cases, exhibited a relatively avascular corridor extending toward the infratemporal fossa, now quantitatively defined relative to the PPG and surrounding vascular structures. These findings provide anatomical support for posteriorly directed trajectories used in percutaneous infrazygomatic and suprazygomatic approaches, in which advancement along the posterior wall may allow access to the PPG while minimizing the risk of vascular injury.