Anastomosis between the internal carotid and vertebral artery in the neck

Thrombectomy by Direct Cervical Access in Case of Common Carotid Occlusion with Collateral Supply to Internal Carotid Artery: Uncommon Anatomic Variant

BACKGROUND

Mechanical thrombectomy for acute ischemic stroke recently proved its superiority to standard medical management alone. With the increasing number of procedures, practitioners are exposed to unexpected situations that may lead to failure of access and significantly worse clinical outcome. Being able to plan the procedure and use alternative techniques may be useful in case of peculiar anatomy.

CASE DESCRIPTION

We report here the case of a 60-year-old man referred to our institution for an acute ischemic stroke. The patient had an initial National Institutes of Health Stroke Scale score of 19. The patient's medical history revealed an unspecified cervical treatment at the level of C5-C6 20 years previously. Magnetic resonance imaging showed a left M1 occlusion and the absence of ipsilateral common carotid. The digital subtraction angiography revealed an anastomosis through the left inferior and superior thyroid artery. Mechanical thrombectomy was performed through direct cervical access with a TICI 3 recanalization score.

CONCLUSIONS

Absence of viable access to perform mechanical thrombectomy during acute ischemic stroke is a rare but pejorative event. Direct common carotid puncture, even in its distal segment, when necessary is a feasible technique to perform internal carotid catheterization.

Dangerous extracranial-intracranial anastomoses and supply to the cranial nerves: vessels the neurointerventionalist needs to know

Transarterial embolization in the external carotid artery (ECA) territory has a major role in the endovascular management of epistaxis, skull base tumors, and dural arteriovenous fistulas. Knowledge of the potential anastomotic routes, identification of the cranial nerve supply from the ECA, and the proper choice of embolic material are crucial to help the interventionalist avoid neurologic complications during the procedure. Three regions along the skull base constitute potential anastomotic routes between the extracranial and intracranial arteries: the orbital, the petrocavernous, and the upper cervical regions. Branches of the internal maxillary artery have anastomoses with the ophthalmic artery and petrocavernous internal carotid artery (ICA), whereas the branches of the ascending pharyngeal artery are connected to the petrocavernous ICA. Branches of both the ascending pharyngeal artery and the occipital artery have anastomoses with the vertebral artery. To avoid cranial nerve palsy, one must have knowledge of the supply to the lower cranial nerves: The petrous branch of the middle meningeal artery and the stylomastoid branch of the posterior auricular artery form the facial arcade as the major supply to the facial nerve, and the neuromeningeal trunk of the ascending pharyngeal artery supplies the lower cranial nerves (CN IX-XII).