Morphometric Analysis of Abducens Nerve and Petroclinoid Ligament in Dorello’S Canal: A Cadaveric Study with Clinical Implications
Sarbani Das, Amit Kumar Pal, Ankita SahaBackground:
The Abducens cranial nerve (VI) is a motor cranial nerve which is vulnerable to injury due to its extensive intracranial course. One of its most critical segments traverses the Dorello’s canal, an osteofibrous tunnel bounded superiorly by the petroclinoid ligament (PCL).
Objective:
Primary - To perform a detailed morphometric analysis of the Abducens nerve and petroclinoid ligament within Dorello’s canal in a cadaveric population from Eastern India. Secondary - To evaluate anatomical variations, ossification patterns, and their relevance in surgery.
Materials and Methods:
A cross-sectional descriptive study was conducted on 40 samples from 20 adult embalmed cadaveric heads of Eastern Indian origin. A systematic morphometric analysis was performed within Dorello’s canal, focusing on VI CN and PCL. Statistical analysis was conducted using SPSS version 26.
Results:
The mean Abducens nerve diameter at dural entry was 1.41 ± 0.09 mm, and the mean dural entry aperture measured 1.75 ± 0.17 mm. The PCL was present in all specimens, most commonly as a single band (70%). Variant morphologies included expanded sheet-like (10%), Y-shaped (7.5%), double band (5%), trifurcated (5%), and hypoplastic (2.5%) configurations. Mean PCL length and width were 10.45 ± 2.70 mm and 1.86 ± 0.76 mm, respectively. The Abducens nerve coursed deep to the PCL in 95% of cases, with a transligamentous variant observed in 5%. PCL ossification was identified in 7.5% of specimens.
Clinical Significance:
Anatomical knowledge of Dorello’s canal with regional variations is crucial for optimizing surgical outcomes of skull base tumors, enhancing diagnostic interpretation in petroclival pathologies, including Gradenigo’s syndrome.