Presentation
Fight with left orbital stab wound by a screwdriver, facial trauma and bleeding per nose and mouth. Patient is dizzy and vomiting blood. No neurological defecit.
Patient Data
CT paranasal sinus in bone window demonstrates air pockets along the medial aspect of the left orbit traversing the left lamina papyracea/vertical plate of left ethmoid, bilateral ethmoid air cells, nasal septum, left side of sphenoid sinus, left pterygoid fossa and the bony canal of the horizontal left petrous temporal bone with involvement of the right petrous canal roof.
Irregularity of the arterial wall of the horizontal petrous part of the right internal carotid artery with small hypoattenuating foci within corresponds to tiny air locules in the right petrous canal.
The case was managed conservatively. A follow-up non-contrast CT brain done on the next day showed a right MCA territory infarct. This is can be caused by arterial spasm/dissection secondary to trauma.
Case Discussion
An uncommon mechanism of internal carotid artery injury, while the direct trauma was through the left orbital socket and injured the right ICA. Amazingly it did miss the left orbit.
The fracture tract raised bony chip of the petrous canal, irregular wall of the petrous ICA and suspected minimal contrast extravasation; all raised the potential of arterial injury. Being a tiny bony canal rendered a full assessment of the vessel hard by CT; though the aforementioned findings highly raised the possibility.
Again being in a bony canal mostly saved the patient from a catastrophic bleed, as it was "contained" by the tamponade effect.
Secondary spasm of the right ICA due to the direct trauma could have caused the right MCA infarct within less than 24 hours. Another theory is dissection extending into the right MCA.
The patient shifted to a neuroradiology centre where carotid angiogram showed pseudoaneurysm formation.