Endovascular thrombectomy (EVT) and best medical treatment are both effective and safe options for patients with acute extracranial internal carotid artery occlusions, according to a study published January 21 in Radiology.
The finding is from an analysis that compared outcomes between the treatments among 354 patients and offers valuable information, as these types of strokes are challenging to treat, noted lead author Lukas Meyer, MD, of University Medical Center Hamburg, and colleagues.
“Increasing evidence has shown beneficial treatment effects of EVT across many subgroups. However, some subgroups, such as isolated acute [internal carotid artery] occlusions below the circle of Willis, remain insufficiently investigated,” the group wrote.
Symptomatic acute occlusions of the internal carotid artery (ICA) below the circle of Willis – a junction of arteries just below the hypothalamus — can cause a variety of stroke symptoms, even if the major intracranial cerebral arteries remain unobstructed, the authors explained.
EVT is a minimally invasive image-guided surgical procedure that can be used to dissolve these occlusions and restore blood flow to prevent further brain damage, yet how the procedure compares to best medical treatment such as intravenous thrombolysis is not well established, they noted.
To address the knowledge gap, the researchers explored the role of EVT versus best medical treatment in 354 patients from 22 comprehensive stroke centers in Europe and Asia. Of these patients, 291 (82%) underwent EVT and the rest were managed with best medical treatment. The researchers assessed functional and clinical outcomes, safety measures, mortality, and procedural complications.
Key results included the following:
- Both treatments resulted in comparable rates of favorable functional outcomes, with no statistically significant difference between treatment options (adjusted odds ratio [AOR], 0.82; p = 0.68).
- EVT led to complete recanalization of ICA occlusions in 80.9% (229 of 283) of patients, but periprocedural distal embolization occurred in 27.8% (81 of 291) of patients, which was associated with poor outcomes (AOR, 0.41; p = 0.03).
- An adjusted analysis showed no difference between the occurrence of symptomatic intracerebral hemorrhages (AOR, 1.48; p = 0.6) and long-term mortality (AOR, 0.43; p = 0.07) between EVT and best medical treatment, indicating no differences regarding safety.
“For patients with symptomatic acute occlusions of the internal carotid artery below the circle of Willis, endovascular and best medical treatment were both effective and safe therapeutic options,” the researchers wrote.
Ultimately, the overall numbers of patients included in the study and the distribution between treatment arms were imbalanced and thus are likely not sufficiently powered to detect differences in treatment effects, the authors noted. Moreover, while recanalization (restoration of blood flow) in an occluded ICA lesion with EVT is associated with improved outcomes, its risk for periprocedural downstream emboli may compromise favorable outcomes, they wrote.
In an accompanying editorial, Badih Junior Daou, MD, and Neeraj Chaudhary, MD, both of the University of Michigan Health, noted that despite the study’s limitations, it adds valuable information due to the scarcity of studies about acute extracranial ICA occlusions.
“EVT with mechanical thrombectomy, angioplasty, and carotid artery stenting offers a promising alternative or adjunct to medical therapy, although one must weigh the risk of distal embolization and reperfusion injury against the severity of the clinical presentation,” the pair wrote.
Further large-scale studies evaluating acute extracranial ICA occlusions are needed to clarify optimal patient selection criteria for endovascular therapy to improve patient outcomes, Daou and Chaudhary concluded.
The full study is available here.