Classification and management strategy of spontaneous carotid artery dissection

Spontaneous carotid artery dissections (sCADs) are the common cause of stroke in middle-aged and young people. There is still a lack of clinical classification to guide the management of sCAD. We reviewed our experience with 179 patients with sCAD and proposed a new classification for sCAD with prognostic and therapeutic significance.

This is a retrospective review of prospectively collected data from June 2018 to June 2023 of patients with sCAD treated at a large tertiary academic institution in an urban city in China. Based on imaging results, we categorize sCAD into four types: type Ⅰ, intramural hematoma or dissection with <70% luminal narrowing; type Ⅱ, intramural hematoma or dissection with ≥70% luminal narrowing; type Ⅲ, dissecting aneurysm; type ⅣA, extracranial carotid artery occlusion; and type ⅣB, tandem occlusion. We compared the clinical data and prognostic outcomes among various types of sCADs.

A total of 179 patients and 197 dissected arteries met the inclusion criteria. The mean age of the 179 patients with sCAD was 49.5 years, 78% were male, and 18 patients (10%) had bilateral sCAD. According to our classification, there were 56 type Ⅰ (28.4%), 50 type Ⅱ (25.4%), 60 type Ⅲ (30.5%), and 31 type Ⅳ (15.7%) dissections. During a mean hospitalization length of 11.4 ± 47.0 days, there were nine recurrent strokes (4.6%) after medical treatment, two type Ⅲ dissections (1.0%), seven type Ⅳ dissections (3.6%), all ipsilateral, and one death. Overall, there were seven (3.6%, 1 type Ⅰ dissection, 3 type Ⅱ dissections, 2 type Ⅲ dissections, and 1 type Ⅳ dissection) recurrent strokes and three (1.5%, all type Ⅲ dissections) recurrent transient ischemic attacks in patients treated with just medical therapy during the follow-up period, all ipsilateral, with a mean follow-up of 26 months (range, 3-59 months). These patients did not undergo further intervention due to the high difficulty associated with endovascular treatment (EVT) or the mild nature of recurrent cerebral ischemic symptoms. Twenty-nine type I dissections (51.8%) were completely recanalized after antithrombotic therapy. A total of 19 type II dissections (38%) and 44 type III dissections (73%) received EVT for persistent flow-limited dissections, enlargement of dissecting aneurysms, or aggravation of neurological symptoms despite antithrombotic therapy. Type Ⅳ dissections are more likely to lead to the occurrence of ischemic stroke and presented with more severe symptoms. Eight type IVB dissections (33%) received acute phase intervention due to distal thromboembolism or aggravation of neurological symptoms after medical treatment. In terms of cerebral ischemic events and mortality, there were no statistically significant differences among the four types of sCAD (all P > .05). Favorable outcome was achieved in 168 patients (93.9%).

This study proposed a novel and more comprehensive classification method and the modern management strategy for sCAD. Antithrombotic therapy is beneficial to reduce the risk of recurrent stroke for stable sCAD. Non-emergent EVT can be an alternative therapeutic approach for patients who meet indications as in type II to IVA dissections. Urgent procedure with neurovascular intervention is necessary for some type IVB dissections. The short-term results of EVT for sCAD are encouraging, and long-term device-related and functional outcomes should undergo further research.