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. 2020 Sep 10;83(1):37-43.
doi: 10.1055/s-0040-1716691. eCollection 2022 Feb.

Morphometric Study of the Posterior Fossa: Identification of Practical Parameters for Tailored Selection of Surgical Routes to the Petroclival Region

Zaid Aljuboori  1 , Ahmad Alhourani  1 , Mohammed Nuru  1 , Candice Nguyen  1 , Heegook Yeo  1 , Brian Williams  1 , Norberto Andaluz  1
Affiliations

Morphometric Study of the Posterior Fossa: Identification of Practical Parameters for Tailored Selection of Surgical Routes to the Petroclival Region

Zaid Aljuboori et al. J Neurol Surg B Skull Base. .

Abstract

Introduction The petroclival region is an integral part of the skull base. It can harbor different pathologies and provides access to the petroclival junction and cerebellopontine angle. We present the results of the morphometric analysis of the posterior fossa and a prediction model to enable skull base surgeons to choose an optimal surgical corridor considering patient's bony anatomy. Methods Ninety patients (14 to assess interobserver reliability) with temporal bone computed tomography were selected. Exclusion criteria included patients <18 years of age, radiographic evidence of trauma, infection, or previous surgery. The images were analyzed using OsiriX MD (Bernex, Switzerland). We recorded clival length, vertical angle, and surface area, and petroclival angle, petrous apex, and translabyrinthine corridors volume. Results The average age was 49.5 years (55%) for males. The mean clival length and surface areas were 44.2 mm (standard deviation [SD] ± 4.1) and 8.1 cm 2 (SD ± 1.3). The mean petrous apex and translabyrinthine corridors volumes were 2.2 cm 3 (SD ± 0.6) and 10.1 cm 3 (SD ± 3.7). The mean petroclival angle at the internal auditory canal (IAC) was 154.9 degrees (SD ± 9). The clival length correlated positively with clival surface area (rho = 0.6, p <0.05), petrous apex volume (rho = 0.3, p < 0.05), and translabyrinthine volume (rho = 0.3, p < 0.05). Conclusion The petroclival region is complex and with high variability of surgical significance. The use of preoperative measurements of the clival length and petroclival angle as part of surgical planning that could help the surgeon to choose an optimal surgical corridor by overcoming the anatomical variability elements.

Keywords: approaches; clivus; petroclival; petrous apex; prediction; skull base.

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Conflict of interest statement

Conflict of Interest B.J.W. reports other from Monteris medical, outside the submitted work. All the other authors report no conflict of interest.

Figures

Fig. 1
Fig. 1
CT scan images (sagittal view) show ( A ) clival length (short), ( B ) clival length (long).
Fig. 2
Fig. 2
CT scan images show ( A ) clival surface area measurement (coronal view), ( B ) a 3-D reconstruction of the clivus.
Fig. 3
Fig. 3
CT scan images (axial view) show ( A ) wide petroclival angle, ( B ) narrow petroclival angle.
Fig. 4
Fig. 4
CT scan images (coronal view) show ( A ) short IAC-JF distance, ( B ) long IAC-JF distance.
Fig. 5
Fig. 5
CT scan images show ( A ) narrow clival angle (sagittal view), ( B ) narrow IAC angle (axial view).
Fig. 6
Fig. 6
CT scan images show ( A ) wide clival angle (sagittal view), ( B ) wide IAC angle (axial view).
Fig. 7
Fig. 7
A cross-correlation map shows the correlation between different anatomic variables. [CL, clival length; CSA, clival surface area; CT, clival thickness; CVA, clival vertical angle; CCD, central clival depression; IAC, internal auditory canal; PCF, petroclival fissure; JF, jugular foramen.
Fig. 8
Fig. 8
A scatter plot shows the linear correlation between the clival length and translabyrinthine ( A ), Petrous apex ( B ), and transclival ( C ) corridors.
See this image and copyright information in PMC

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