Sonographic Evaluation of Complications of Extracranial Carotid Artery Interventions

Intimal Injury Potentially Plays a Key Role in the Formation of Carotid Artery Dissection: A Novel Animal Model Establishing

Research on the pathophysiological mechanism of carotid artery dissection and its clinical translation is limited due to the lack of effective animal models to simulate the occurrence of this condition. Assuming that intimal injury is an important factor in the formation of carotid dissection, we established a novel method for inducing carotid dissection models by scraping the carotid intima using a fine needle. Scraping the carotid intima with fine needles can induce the rapid formation of carotid dissection. Magnetic resonance imaging and hematoxylin-eosin staining suggest the presence of false lumens and mural hematomas in the vessels. Our model-induction technique, inspired by iatrogenic catheter-induced artery dissections (carotid, coronary, aortic), significantly mimics the pathological process of clinical carotid dissection. The results suggest that mechanical injury may be a significant cause of carotid dissection and that intimal injury is a major factor in the formation of arterial dissections. This approach will provide assistance in the understanding of medically induced arterial dissection.

Ultrasound diagnosis of carotid artery stenosis and occlusion

Carotid artery ultrasonography is capable of diagnosing or inferring the presence or absence of stenosis or occlusion of the internal carotid artery (ICA) and vertebral artery (VA), as well as the not directly observable distal ICA, middle cerebral artery (MCA), and basilar artery (BA). Stenosis at the origin of the ICA is mainly evaluated using the parameter peak systolic velocity (PSV), with values of ≥ 200-230 cm/s indicating severe stenosis. Recently, the acceleration time ratio has been reported for diagnosis of ICA origin stenosis. An indicator called the end-diastolic (ED) ratio can be used for diagnosing occlusion of the distal ICA or the M1 segment of the MCA. The PSV of stenosis can be used to diagnose stenosis at the beginning of the VA or V1, and mean flow velocity, mean ratio, and diameter ratio can be used to diagnose distal VA occlusion. Furthermore, the usefulness of the VA pulsatility index and resistance index has been suggested for diagnosing stenosis or occlusion of the BA. This review outlines diagnostic sonography criteria for stenosis and occlusion of extracranial and intracranial arteries.

Ileal hemorrhagic infarction after carotid artery stenting: A case report and review of the literature

BACKGROUND

Ileal hemorrhagic infarction after carotid artery stenting (CAS) is a fatal complication. The prognosis of ileal hemorrhagic infarction after CAS is very poor if not treated in a timely manner. We describe a rare case of ileal hemorrhagic infarction due to acute embolism of the mesenteric artery after CAS.

CASE SUMMARY

A 67-year-old man with acute ischemic stroke underwent CAS via the right femoral artery approach 21 d after intensive medical treatment. On the first day after surgery, the patient had abdominal distension and abdominal pain. Abdominal enhanced computed tomography revealed intestinal obstruction, severe stenosis of the superior mesenteric artery, and poor distal angiography. An exploratory laparotomy was performed, and pathological examination showed hemorrhagic ileal infarction. It was subsequently found that the patient had intestinal flatulence. With the guidance of an ultrasound scan, the patient underwent abdominal puncture, drainage, and catheterization. After 58 d of treatment, the patient was discharged from hospital with a National Institutes of Health Stroke Scale score of 2 points, and a Modified Rankin Scale score of 1 point. At the 6-mo follow-up, the patient had an excellent functional outcome without stroke or mesenteric ischemia. Furthermore, computed tomography angiography showed that the carotid stent was patent.

CONCLUSION

Ileal hemorrhagic infarction is a fatal complication after CAS, usually caused by mesenteric artery embolism. Thus, more attention should be paid to the complications of embolism in the vascular system as well as the nervous system after CAS, and the complications should be identified and treated as early as possible.