Petrolingual ligament

The petrolingual ligament is the posteroinferior attachment of the lateral wall of the cavernous sinus, where the internal carotid artery enters the cavernous sinus. 

The petrolingual ligament surrounds part of the dorsal and lateral walls of the lacerum segment of the internal carotid artery (ICA), just under the anteroinferior portion of the anteromedial wall of cavum trigeminal (Meckel’s cave).

The petrolingual ligament is spanned from the lingula of the sphenoid bone anteriorly to the petrous apex posteriorly and covers the superolateral surface of the lacerum segment of the internal carotid artery. The petrolingual ligament is bow shaped and can be divided into three portions: anterior wing, body and posterior wing. The anterior wing insert onto the lingula, which was a crest-shaped or thorn-shaped bony projection, arising from the lateral aspect of the carotid sulcus and projecting posteriorly for a variable distance. The posterior wing is mixed with the fibers of the the petroclinoid ligament (petrosphenoidal ligament) at the superior aspect of the petrous apex.

The petrolingual ligament is located medial to the lacerum segment of the internal carotid artery and lateral to the medial surface of cavum trigeminal (Meckel’s cave). The posteroinferior tip of the body is located deep to the junction of the maxillary division (V2) and the mandibular division (V3) at the trigeminal (Gasserian) ganglion. The superior margin of the petrolingual ligament run parallel to the abducens nerve. The greater petrosal nerve cross anterolaterally to the petrolingual ligament and the internal carotid artery and ran into the fibrocartilaginous tissue filling the foramen lacerum.

The petrolingual ligament demarcates two of the segments of the internal carotid artery, the petrous part of the internal carotid artery inferiorly and the cavernous part of the internal carotid artery superiorly.

The ligament is surgically important due to its identification as a landmark for dissection of the internal carotid artery during the approaches to posterolateral intracavernous and extracavernous lesions.