Related Experiment Video
Updated: Apr 10, 2026
Coronoid-Temporalis Pedicled Flap for Orbital Floor Defect Reconstruction
Published on: December 5, 2025
Biportal Endoscopic Transorbital Approach with an Accessory Lateral Orbital Port for Anterior Petrosal Corridor : A
Seonah Choi1, Woo Hyun Kim2, Soo Jeong Park3
1Department of Neurosurgery, Brain Tumor Center, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Objective:
The anterior transpetrosal approach (ATPA) is one of the useful methods for targeting the middle clival and ventrolateral pontine areas. Thanks to the advances in endoscopic skull base surgery, there have been increased attempts to perform anterior petrosectomy via the endoscopic transorbital approach (ETOA), although some limitations and drawbacks have also been suggested. This study aimed to analyze the contribution of the endoscopic biportal transorbital technique to anterior petrosectomy.
Methods:
A total of ten cadaveric heads (twenty sides) were dissected at the Surgical Neuroanatomy Laboratory. The biportal ETOA was established by combining the main transorbital port with an accessory lateral orbital port created beyond the lateral orbital rim. In each head, anterior petrosectomy through uniportal ETOA was performed on one side, followed by the biportal ETOA on the same side, while the transcranial subtemporal ATPA was done on the other side. The extent of exposure for each approach was documented using representative photographs obtained during dissection. The angle of attack (AOA) was measured at key surgical landmarks, including Meckel's cave, the root entry zone (REZ) of cranial nerves V, VI, VII, and VIII, and the internal acoustic porus. The drilled volume of the petrous apex was calculated by comparing pre- and post-dissection CT scans.
Results:
By utilizing the accessory port, it was possible to obtain a more medial trajectory, allowing wider exposure of CN V, CN VI, CN VII, CN VIII, and the ventrolateral pons than the uniportal approach. The angle of attack (AOA) increased with the biportal transorbital approach compared to the uniportal route by approximately 26.1-46.7% in the horizontal axis, 21.6-52.4% in the vertical axis. When measuring the drilled volume of the petrous apex, no statistically significant difference was observed between the biportal ETOA and the traditional transcranial craniotomy method. (0.9339 ± 0.1037 vs 0.9729 ± 0.0692 cm3, p = 0.067).
Conclusion:
This study demonstrates that the biportal ETOA can compensate for the limitations of the uniportal approach in performing anterior petrosectomy by providing a wider field of view and greater surgical freedom.m neurodevelopmental outcomes in vulnerable pediatric neurosurgical patients.
