Applied microanatomy of the petrous internal carotid artery, greater superficial petrosal nerve, and tensor tympani muscle to improve safety during middle fossa surgery: laboratory cadaveric investigation

Authors

Ali Tayebi Meybodi, The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, United States.
Andrea L. Castillo, The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, United States.
Michael T. Lawton, The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, United States.
Mark C. Preul, The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, United States. Electronic address: Neuropub@barrowneuro.org.

Document Type

Article

Abstract

BACKGROUND: Middle cranial fossa surgery is challenging due to the proximity of several neurovascular structures, such as the otic capsule, greater superficial petrosal nerve (GSPN), and petrous internal carotid artery (pICA). The concept of middle fossa triangles aids in the recognition of landmarks and increases the safety of middle fossa surgery. However, a definitive description of the microanatomical interrelationship between the pICA, tensor tympani, and GSPN in middle fossa surgery is lacking. METHODS: This study investigates the relationship between the GSPN, pICA, and tensor tympani to improve the safety of pICA exposure during surgery of the middle fossa. The middle fossae of 5 cadaveric heads (10 sides) were drilled to expose the GSPN, pICA, and tensor tympani. The crossing points between the pICA, GSPN, and tensor tympani were recorded for the proximal and distal pICA using a stereotactic navigation system. Distances between the crossing points and the borders of the horizontal pICA were calculated. The GSPN and pICA crossed in all specimens. RESULTS: The mean (SD) distance between the GSPN and pICA was 3.0 (4.9) mm proximally and 5.3 (2.8) mm distally. The tensor tympani was lateral to the pICA with a mean (SD) distance of 4.2 (1.9) mm in all specimens (proximally and distally), except in 1 specimen in which it crossed only the proximal pICA. CONCLUSIONS: Drilling the Kawase triangle on the medial side of the GSPN is not universally safe because the pICA and GSPN frequently cross along the course of the horizontal pICA. The tensor tympani muscle may be used as a reliable landmark to systematically localize the pICA.

Medical Subject Headings

Humans; Cadaver; Carotid Artery, Internal (anatomy & histology, surgery); Cranial Fossa, Middle (surgery, anatomy & histology); Tensor Tympani (anatomy & histology, surgery); Neurosurgical Procedures (methods); Petrous Bone (anatomy & histology, surgery)

Publication Date

11-1-2025

Publication Title

Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia

E-ISSN

1532-2653

Volume

141

First Page

111561

PubMed ID

40829245

Digital Object Identifier (DOI)

10.1016/j.jocn.2025.111561

Recommended Citation

Tayebi Meybodi, Ali; Castillo, Andrea L.; Lawton, Michael T.; and Preul, Mark C., "Applied microanatomy of the petrous internal carotid artery, greater superficial petrosal nerve, and tensor tympani muscle to improve safety during middle fossa surgery: laboratory cadaveric investigation" (2025). Neurosurgery. 2238.
https://scholar.barrowneuro.org/neurosurgery/2238