Invited commentary

Abstract

In a follow-up study of 696 patients with atherosclerotic occlusion of the cervical internal carotid artery, the authors discovered spontaneous recanalization (SR) in 16 patients (2.3%). The mean interval from the diagnosis of occlusion to the discovery of SR was 38 months (range, 5-98 months). Aspirin was the only coagulation modifier used in most patients with carotid occlusion experiencing SR. Of the 16 SR patients, 1 sustained a transient ischemic attack, 1 had a contralateral cardioembolic neurologic event, and 2 patients had nonhemispheric symptoms leading to the diagnosis of SR. The remaining 12 patients were asymptomatic. No patient sustained a stroke at the time of SR. The images provided by the authors reveal that the recanalized arteries have only thread-like lumens, with barely perceptible flow. On long-term follow-up after SR (mean, 71.2; range, 1-157 months), 1 patient had chronic nonhemispheric symptoms, 2 patients died of cancer without neurologic symptoms, and the remaining 13 patients were alive and asymptomatic. No patient experienced a stroke referable to the recanalized artery. The authors make four significant observations with respect to SR. First, it is uncommon (2.3%), but perhaps not as uncommon as it was previously thought to be. Second, it is usually an asymptomatic event. Third, SR restores a diminutive lumen with minimal flow not likely to contribute significantly to overall cerebral blood flow or to be a source of emboli. Finally, in long-term follow-up, recanalized arteries remain asymptomatic. In fact, no patient in their study sustained a stroke referable to the recanalized artery. From these observations, we can conclude first, that SR is not a clinically significant event, and second, that treatment of a recanalized artery in an attempt to enlarge the lumen and restore significant antegrade flow is unwarranted. Although it would seem tempting to cross the lesion with a guidewire and then to stent open the irregular and diminutive lumen, this cannot be justified based on these authors' experience. More plainly, after a well-documented atherosclerotic cervical internal carotid artery occlusion, the diagnosis of carotid recanalization by duplex, magnetic resonance angiography, computed tomography angiography, or catheter angiography is not an indication for intervention. The authors' observations and the conclusions logically drawn from them are timely. SR will be diagnosed more frequently as our carotid disease and stroke patients live longer and more often undergo cerebrovascular imaging studies with continually improving sensitivity for the detection of even minimal flow. The knowledge that SR is associated with a benign natural history should prevent well intentioned, but unnecessary, ill-advised, and potentially dangerous interventions. Benign outcome of objectively proven spontaneous recanalization of internal carotid artery occlusionJournal of Vascular SurgeryVol. 53Issue 2PreviewSpontaneous recanalization of intracranial internal carotid artery (ICA) occlusion is frequent in embolic strokes. Spontaneous recanalization of the extracranial portion of the ICA occlusion of atherosclerotic or embolic origin is only anecdotally reported, and data are lacking about its incidence, natural history, and outcome in long-term follow-up. Full-Text PDF Open Archive