Related Experiment Video
Updated: Jun 26, 2025
Role of Diffusion MRI Tractography in Endoscopic Endonasal Skull Base Surgery
Published on: July 5, 2021
Retrolabyrinthine approach to the lateral skull base: The value of preoperative temporal bone CT analysis
Fabrizio Salvinelli1, Francesca Bonifacio2, Carlo A Mallio3
1Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo, 21 - 00128, Rome, Italy; Multidisciplinary Group for Skull base surgery, Università Campus Bio-Medico di Roma, Rome, Italy.
Purpose:
The most used neurosurgical approach to reach cerebellar-pontine angle is the retrosigmoid route. This article describes the presigmoid approach which requires excellent knowledge of the labyrinthine block together with quantitative analysis of temporal bone CT.
Methods:
CT-based quantitative measurements were obtained in patients undergoing vestibular neurectomy with a presigmoid approach. Eighteen patients were enrolled, and five measures were taken: Trautmann's area, the petro-clival angle, presigmoid dura length and its angle. The relationship between these measurements and hospitalization days, operating times, and complications was explored.
Results:
The posterior semicircilar canal (PSC)-sigmoid sinus (SS) distance, presigmoid dura- internal auditory canal (IAC)-PSC angle, and duration of surgery are predictors of complications. Specifically, a PSC-sigmoid sinus distance <11 mm, a dura presig-IAC-PSC angle <14 are associated with the highest risk of complications.
Conclusion:
Preoperative temporal bone CT scan can guide the surgeon through the narrowest areas of the surgical approach. Trautmann's triangle area and petro-clival angle reduction are challenging and can be faced with combined microscopic-endoscopic technique, and with optics angulation-rotation. The retrolabyrinthine approach can enable hearing preservation and minimal cerebellar retraction.
