Radiology Expert Witness Discusses Dissected Carotid Artery

This nuclear medicine case involves a seventy-four-year-old woman who had a fall at her residence. She was subsequently taken to the emergency department. Immediately after her arrival, an ensuing stroke was suspected, and interventional radiology was consulted. A CT showed ischemic stroke, and the patient was then sent for a MERCI clot retrieval. Upon entering the carotid artery, severe carotid artery stenosis was identified but shortly after a dissection occurred rendering the clot inextricable. This decreased cerebral perfusion leading to global ischemia in the brain parenchyma. Unfortunately, the patient was left permanently disabled, with left-sided paralysis and fully dependent for all activities of daily living. A cardiovascular radiology expert was sought to opine on the case.

Question(s) For Expert Witness

1. Should the carotid artery be dissected when performing MERCI clot retrieval?

Expert Witness Response E-000570

A number of mechanical thrombectomy devices are on the market, MERCI being one of the main methods used today. It is approved in the United States and Europe for clot removal within 8 hours of acute stroke symptom onset in selected patients. Procedural complications in MERCI, including embolization, dissection, subarachnoid hemorrhage, vessel perforation, and groin hemorrhages, which occurred in 13 percent and were considered clinically significant in 7 percent. Due to the high risk of carotid artery dissection, it is highly recommended to evaluate perfusion with carotid Doppler ultrasound to check for stenosis before MERCI to avoid dissection.