Atypical attachment of the petrosphenoidal (petroclival) ligament to the posterior genu of the cavernous internal carotid artery – Case report

Abstract

IntroductionThe petrosphenoidal ligament (also termed as petroclival ligament) was described in 1859 by Wenzel Gruber, a Russian anatomist. Hence, the popular eponym of Gruber's ligament. Typically, the petrosphenoidal ligament is stretched between the petrous apex and in the vicinity of the posterior clinoid process, forming the posteromedial wall of the Dorello's canal located within the inferomedial paraclival triangle. This report presents a previously unreported attachment of the petrosphenoidal ligament to the posterior genu of the cavernous internal carotid artery. Since the ligament can be a helpful landmark during neurosurgical procedures, our report might have practical value. Case descriptionDuring routine dissection of the isolated sagittal section of the head from a male cadaver, an atypical attachment of the petrosphenoidal (petroclival) ligament was observed. The proximal ligament's attachment was bifid. Some ligament bundles originated from the lateral aspect of the clivus, while another group of bundles originated from the posteromedial aspect of the posterior genu of the cavernous internal carotid artery. The ligament had a triangular shape with a broader distal attachment to the petrous apex. The meningohypophysial trunk was in juxtaposition to the arterial attachment of the ligament. It was noted that the arterial attachment was well-fixed to the internal carotid artery's adventitia. ConclusionsThe dual origin of the petrosphenoidal ligament to the clivus and internal carotid artery's posterior genu causes atypical fixation of both structures. It can potentially alter selected surgical procedures, such as mobilization of the internal carotid artery's short vertical segment and posterior genu.