María Gutiérrez, MD
Large vessel occlusion of the posterior circulation has devastating effects and carries high morbidity and mortality. One of the main causes for this stroke subtype is vertebral atherosclerosis. The optimal treatment for the non-acute intracranial vertebral artery occlusion (NA-ICVAO) in patients at high risk of stroke despite the best medical treatment remains unclear. Some case-report studies showed that endovascular recanalization (ER) is feasible. However, a large heterogeneity of perioperative outcomes and a high incidence of complications makes critical to identify which patients would benefit from intervention.
In this study, the authors aimed to define an angiographic classification to explore the feasibility and safety of endovascular recanalization for symptomatic atherosclerotic NA-ICVAO that might become a reference for patient selection and risk stratification in future trials. They retrospectively analyzed 50 patients with atherosclerotic NA-ICVAO that were treated with angioplasty and stenting. Patients were divided into 4 groups according to the following angiographic classification: type I (Figure 1A), the occlusion length is ≤15 mm; type II (Figure 1B), the occlusion length is >15 mm; type III (Figure 1C and 2), the occlusion length is >15 mm, and the tortuosity angle of the occluded segment is ≥45°; and type IV (Figure 1D), the occlusion extends to the epidural segment.
The median duration of occlusion was 45 days, and the median time from last symptom onset to endovascular treatment was 15 days. The overall technical success rate was 76%. The perioperative complication rate was 16% (8/50); vascular dissection occurred in 5 cases (4 asymptomatic and 1 mild stroke). One patient died of vascular perforation. Stroke or death beyond 30 days was 10.2% (5/49), 2 patients died (one for cerebral hemorrhage and another from ischemic stroke), 1 patient experienced severe ischemic stroke, and 2 patients had mild ischemic stroke. In angiographic follow-up, 4 patients developed in-stent restenosis and 3 developed reclusions.
Regarding the angiographic classification, type I was the most favorable, with recanalization rates of 94.1% and a complication rate of 0%. Type II, III, and IV showed a rate of recanalization of 76%, 70%, and 50% and a complication rate of 7.7%, 20%, and 50%, respectively.
According to these results, it seems that the length of the occlusion and the tortuosity of the vertebral artery is related with the success of recanalization and the rate of complications. Therefore, in those cases in which medical treatment fails to prevent stroke, patients with atherosclerotic NA-ICVAO and a favorable angiographic classification (type I) may benefit from vertebral recanalization.
Although this study has some limitations such as the small sample size and the lack of long-term follow-up, it provides some interesting aspects to objectively evaluate risk-benefits of recanalization in order to decide the best therapeutic option for such type of patients. Prospective multicentric registries or clinical trials would be welcome to establish the utility of such approach.