Comparative Anatomical Study On The Three Endoscopic Transnasal Transantral Operative Approach In The Pterygopalatine Fossa Region.

Objective: The purpose of this study is to find some endoscopic landmarks that are useful for location of the neurovascular structures in the pterygopalatine fossa and to provide anatomic basis for the selection of operative approach in relation to the endoscopic transnasal surgery in the pterygopalatine fossa region.Materials and methods: An anatomical dissection of twelve pterygopalatine fossa in six fresh cadaveric heads prepared with intravascular injection of colored latex was pergormed with rod-lenses endoscope. Finish comparative anatomical study on the middle meatal transantral approach, the inferior turbinectomy transantral approach and the nasal lateral wall dissection transantral approach and anatomical Orientational study on the neurovascular structures in the pterygopalatine fossa.Results: The crista ethmoidalis and sphenopalatine foramen, the prominence of the infraorbital canal and the impression of maxillary artery served as three important endoscopic landmarks in orientation the neurovascular structures in the pterygopalatine fossa. The middle meatal transantral approach allows for exposure of the structures in the superior part of the pterygopalatine fossa, the inferior turbinectomy transantral approach and the nasal lateral wall dissection transantral approach both allow for exposure of all the structures in the pterygopalatine fossa and the structures in the medial part of the infratemporal fossa.The former has advantages in exposure of the structures in the lateral region,and the latter has advantages in exposure of the structures in the medial aera. The plane of the lateral pterygoid muscle is the lateral boundary line of the endoscopic transnasal transantral approach.Conclusion: Our anatomic study shows that these landmarks which was significant to location of all the neurovascular structures in the pterygopalatine fossa will allow the surgeon to enter the region with more accuracy and less complication. There are four major decisive factors in determining the most reasonable endoscopic transnasal transantral approach: the extent of the lesion in the pterygopalatine fossa; invasion with or without the inferior turbinate and the nasolacrimal duct; the extent of the lesion in the maxillary sinus; the operation type.