A. Kaleel, MD, MSc

Luitse MJA, Velthuis BK, Dauwan M, Dankbaar JW, Biessels GJ, and Kappelle LJ. Residual High-Grade Stenosis After Recanalization of Extracranial Carotid Occlusion in Acute Ischemic Stroke. Stroke. 2014

The guidelines for secondary prevention after an acute ischemic stroke are under constant revision as new data becomes available. This study sought to provide insight into the future management of residual high-grade stenosis of the extracranial ICA after treatment of a symptomatic occlusion. This prospective study evaluated 126 patients (86 had adequate follow up imaging and were included in the analysis) from the prospective Dutch acute stroke study (DUST) between May 2009 and May 2013 who suffered an acute occlusion of the internal carotid artery followed by treatment with rtPA, endovascular treatment, mechanical clot disruption or retrieval, or a combination of these. Among these patients, 57.4% were treated with intravenous rtPA and 12.8% underwent endovascular treatment.

Inclusion criteria were clinical diagnosis of acute stroke; non-contrast head CT (NCCT), CT perfusion (CTP), and CT angiogram (CTA) studies performed within 9 hours of symptoms onset; and no known history of renal failure or allergy to contrast agents. Following treatment with one of the aforementioned approaches, assessment was recommended with NCCT, CTP, and CTA within three days after stroke onset with a required follow up imaging window of the carotid artery to be done within seven days of admission.

In 39.5% of the 86 patients the occluded ICA was completely recanalized following treatment, 17.4% had residual stenosis of <30%, 3.5% had residual stenosis of 40-49%, 2.3% had residual stenosis of 50-69%, 16.3% had residual high-grade stenosis of ≥70%, 3.5% had near occlusion, and 57% had persistent occlusion. Of the 14 patients with ≥70% stenosis, 8 were later treated with carotid endarterectomy, indicating that prompt follow up imaging after initial treatment led to added treatment options.

This study concluded that in one out of six patients, there is persistent residual high grade stenosis despite treatment, suggesting that follow up imaging within a week was needed to determine if further treatment may be indicated to prevent recurrent events.