[Applied anatomy of the internal maxillary artery in pterygopalatine fossa under transnasal endoscopic surgery].

OBJECTIVE: To explore the rules about the pathway and branch patterns of the internal maxillary artery in pterygopalatine fossa, provide the anatomic basis for treating the internal maxillary artery during the transnasal endoscopic surgery. METHOD: Ten adult cadaveric skull base were dissected, the sphenopalatine artery and its branches were observed. The pterygopalatine fossa was opened through trans-maxillary sinus endoscopic approach, all the branches of the internal maxillary artery in pterygopalatine fossa were exposed. The concave of the maxillary sinus posterior-medial wall was defined as point A, the cross point of the horizontal line pass through the infraorbital foramen, the maxillary sinus anterior wall and posterior-lateral wall as point B, the cross point of the maxillary sinus anterior wall, floor and posterior-lateral wall as point D, the midpoint of BD as C, the C' denoted the first branch root of internal maxillary artery in pterygopalatine fossa. Observed the pterygopalatine segment of internal maxillary artery based on the marking points. RESULT: The distance between the sphenoid sinus os and the sphenopalatine fossa was (5.88 +/- 2.21) mm. The C' point locate on AC at 13 sides specimen, locate on AB at 5 sides specimen, locate on AC at 1 side specimen, higher than AB at 1 side specimen. CONCLUSION: Being familiar with the pathway and branch patterns of the internal maxillary artery in pterygopalatine fossa is important for treating the uncontrol epistaxis and endoscopic pterygopalatine fossa surgery, the rules described by A, B, C, D in our experiments will be helpful in ligation of internal maxillary artery during the endoscopic transnasal/maxillary-pterygopalatine fossa surgery.