Microanatomic Study On Preauricular Subtemporal-Infratemporal Fossa Approach

Microanatomic Study on Preauricular Subtemporal-infratemporal Fossa ApproachThe preauricular subtemporal-infratemporal fossa approach that is mainly useful for the tumors involving the sphenoid sinus,petrous apex and clivus, creats a simultaneous exposure of the intracranial and extracranial aspects of the middle fossa. The anatomic structure related to the approach is complex. And the Chinese anatomic study related to the approach has been limited until now. Objective: To gain the Chinese anatomic parameters related to the approach. Methods: By imitating the operative procedure of preauricular subtemporal-infratemporal fossa approach under microscope, we studied and measured the anatomic structure related to the approach on fifteen adult cadaveric heads. Results: 1. The frontotemporal branch of the facial nerve runs between the superficial temporalis fascia and the superficial layer of the deep temporalis fascia or in the superficial temporalis fascia, and the distance from the frontal branch of the facial nerve to tragus was 23.4(17-27)mm. The distance from stylomastoid foramen to styloid precess was 5.3(4-7)mm, to the internal aspect of mastoid base was 3.2(2-4)mm. 2. The distance from the mandibular segment of the maxillary artery to articulertubercle was 17.2(15-20)mm, to the top point of mandibular joint capsule was 22.8(19-26)mm. 3. The distance from infratemproal crest to the base of lateral pterygoid process was 20.5(16-23)mm, to foramen ovale was 21.2(17-25)mm. And the distance from foramen ovale to the base of lateral pterygoid process was 3.3(2-5)mm, to foramen spinosum was 2.4(0-5)mm. 4. The distance from the genu of the petrous ICA to the cochlea was 4.8(2-6)mm, to the tympanic cavity was 1.9(1-4)mm. And the distance from the ICA at the external opening of the carotid canal to the line between spine of sphenoid and styloid precess was 4.1(3-6)mm. The depth of the bone between the bony part of the eustachian tube and the genu of the petrous ICA 1.4(1-3)mm. Conclusion : The preauricular subtemporal-infratemporal fossa approach is useful for resection of the tumors occupying the infratemporal fossa and the middle skull base, especially for extradural lesion. Referring to the anatomic parameters related to this approach, surgeons can easily locate the important structure, raise the ratio of tumor resection and decrease complications.