Late spontaneous recanalization of symptomatic atheromatous internal carotid artery occlusion

New Cortical Spot Cerebral Infarction Out of Border Zone in ICA Occlusion Suggests Recanalization: A Case Report

Internal carotid artery occlusion rarely recanalizes spontaneously. Awareness of signs of recanalization is important, as it may necessitate changing the treatment strategy. We report a case of new cortical infarction outside the border zone, which led to the realization of internal carotid artery recanalization and revascularization.

A 76-year-old woman presented with mild dysarthria. Magnetic resonance imaging showed cerebral infarction in the left-hemispheric border zone and occlusion of the internal carotid artery origin. Cerebral angiography performed showed complete occlusion of the internal carotid artery origin and intracranial collateral blood flow from the external carotid artery through the ophthalmic artery. She was diagnosed with infarction due to a hemodynamic mechanism caused by internal carotid artery occlusion and was treated with supplemental fluids and antithrombotic drugs. Four days after hospitalization, the right paralysis worsened and a new cerebral infarction was observed in the cortex, outside the border zone. This infarction appeared to be embolic rather than hemodynamic; thus, we suspected recanalization of the internal carotid artery. The patient underwent emergency cerebral angiography again, which revealed slight recanalization. Thus, emergency revascularization and carotid artery stenting were performed. New cortical infarcts outside the border zone in patients with complete internal carotid artery occlusion is an important finding, suggesting spontaneous recanalization of the occluded internal carotid artery.

Mitophagy in Cerebral Ischemia and Ischemia/Reperfusion Injury

Ischemic stroke is a severe cerebrovascular disease with high mortality and morbidity. In recent years, reperfusion treatments based on thrombolytic and thrombectomy are major managements for ischemic stroke patients, and the recanalization time window has been extended to over 24 h. However, with the extension of the time window, the risk of ischemia/reperfusion (I/R) injury following reperfusion therapy becomes a big challenge for patient outcomes. I/R injury leads to neuronal death due to the imbalance in metabolic supply and demand, which is usually related to mitochondrial dysfunction. Mitophagy is a type of selective autophagy referring to the process of specific autophagic elimination of damaged or dysfunctional mitochondria to prevent the generation of excessive reactive oxygen species (ROS) and the subsequent cell death. Recent advances have implicated the protective role of mitophagy in cerebral ischemia is mainly associated with its neuroprotective effects in I/R injury. This review discusses the involvement of mitochondria dynamics and mitophagy in the pathophysiology of ischemic stroke and I/R injury in particular, focusing on the therapeutic potential of mitophagy regulation and the possibility of using mitophagy-related interventions as an adjunctive approach for neuroprotective time window extension after ischemic stroke.

Functional outcome after symtomatic internal carotid artery occlusion

Abstract Internal carotid artery occlusion accounts for 15-20% of ischemic strokes, caused by atherosclerosis or dissection. Clinical symptoms are variable, from asymptomatic cases to minor or severe strokes. Diagnosis in internal carotid artery (ICA) occlusion is based on imaging techniques. Prognosis after ICA occlusion depends on many factors: severity of neurologic deficit, spontaneous recanalization of the artery, and the occurrence of recurrent strokes. Patients with spontaneous recanalization of the occluded ICA tend to have a retained functional ability and favorable clinical outcomes. Medical treatment, recanalization techniques and intensive rehabilitation program are essential in improving functional outcome of patients with stroke produced by ICA occlusion. We present the case of a young patient diagnosed with ischemic stroke produced by internal carotid artery occlusion, with consecutive severe neurologic deficit, and an unfavorable functional outcome, as evaluated with the Modified Rankin Scale. Spontaneous recanalization of the occluded ICA was observed after 6 weeks, suggesting a carotid dissection. The patient was included in an intensive rehabilitation program, associated with best medical therapy, showing improvement of its functional status at 3 months follow up. Key words: ischemic stroke, carotid artery occlusion, carotid dissection, spontaneous recanalization, functional outcome,

Prognosis of patients with late spontaneous recanalization of the atherosclerotic occlusion of internal carotid arteries: A pilot case series

Late spontaneous recanalization (SR) of an occluded internal carotid artery (ICA) has been rarely reported and the prognosis of affected patients remains elusive. In the present study, the incidence of late SR of atherosclerotic occlusion of the ICA and associated outcomes were assessed in a single center. A total of 36 patients with ICA occlusion, who underwent carotid artery stenting or vertebral artery stenting in arteries other than the occluded ICA, were prospectively included and followed up for ≥18 months. SR was diagnosed by color Doppler ultrasound imaging. The incidence of late SR, the functional outcome and the incidence of adverse cardiovascular events in these patients were evaluated. During the follow-up, three patients had late SR of the occluded ICA (8.3%). All patients had vascular events prior to the confirmation of late SR of the ICA. Subsequent to SR, the patients were clinically stable with preserved functional ability, based on the Modified Rankin Scale. Of these patients, one suffered from re-occlusion of the recanalized ICA without presenting with any novel significant symptoms. In conclusion, patients with late SR of the ICA appear to have preserved functional ability and favorable clinical outcomes. Large-scale cohorts are required to determine the clinical characteristics that contribute to the incidence of late SR of the ICA.

Current understanding of chronic total occlusion of the internal carotid artery

At present, there is limited understanding of chronic total occlusion (CTO) of the internal carotid artery (ICA). Therefore, the present report collected related cases from PubMed and reviewed the literature. Cerebral vessels may form collateral circulation immediately or gradually following CTO of the ICA. The natural history of CTO of the ICA includes a variety of outcomes, all of which are biased toward a non-benign progressive process and are characterized by insufficient cerebral perfusion, embolus detachment and cognitive dysfunction. The majority of cases of CTO of the ICA require treatment. In early studies, the results of external-ICA bypass were unsatisfactory, while recanalization is now considered the only viable option. The current treatment indications mainly depend on the degree of injury to the cerebrovascular reserve and the extent to which the oxygen extraction fraction is increased. The length, height and duration of ICA occlusion are also relevant, though more frequently, the condition depends on multiple factors. Endovascular interventional recanalization, carotid endarterectomy (CEA) and hybrid surgery may be conducted in a select group of patients. As novel materials are developed, the success rate of simple recanalization may gradually increase; however, hybrid surgery may be more representative of the current trend, as advanced CEA can remove carotid atherosclerosis plaques, thus reducing the technological demands of the subsequent interventional recanalization. There are many complications that may result from recanalization following CTO of the ICA, including hyperperfusion and technical errors; therefore, the operation must be conducted carefully. If the recanalization is successful, it typically results in a stable improvement of patient condition in the long term. However, despite these conclusions, more studies are required in the future to further improve current understanding of CTO of the ICA.