BACKGROUND: An aberrant right subclavian artery (ARSA) is a rare vascular anomaly defined by the origin of the right subclavian artery from the aorta, distal to the left subclavian artery (LSA). An ARSA was found in an 83-year-old female during cadaveric dissection for anatomy teaching, which had an unusually narrow lumen compared to previously reported cases.
METHODS: The specific morphology of this ARSA variant was characterised by further dissection and measurements. A systematic review of cadaveric case reports with quantitative evaluation of ARSA dimensions was conducted for comparison with this case.
RESULTS: This ARSA variant exhibited an unusually narrow lumen (8.22 mm²) compared to the LSA (152.55²), with an ARSA: LSA ratio of 0.24. The systematic review included 17 studies with 23 cases of ARSAs. Of these cases, 20 contained details of ARSA diameter, 19 of which were wider than in this case. In all studies where both ARSA and LSA diameters were measured, ARSA was found to be significantly wider than LSA (mean ratio of ARSA to LSA: 1.49, range: 1.09-2.00). Several other variations were reported in these studies, such as concomitant aortic arch branch anomalies and differing origins of ARSA as defined by vertebral level and relation to the aortic arch.
CONCLUSIONS: This case report presents an unusually narrow ARSA which has not been previously described in the literature. As there is limited evidence on how ARSA morphology affects clinical outcomes, further research is needed to better inform management of ARSAs.

BACKGROUND: Perioperative symptomatic carotid artery occlusion after carotid endarterectomy is a rare complication. In this study, we present a case of symptomatic acute carotid artery occlusion that occurred after carotid endarterectomy in a patient with coexistent subclavian artery steal phenomenon, which was successfully treated with subclavian artery stenting.
METHODS: A 57-year-old East Asian female presented with stenosis in the left common carotid artery and left subclavian artery along with subclavian steal. The proximal segment of the left anterior cerebral artery was hypoplastic, and the posterior communicating arteries on both sides were well-developed. Left internal carotid artery stenosis progressed during the follow-up examination; therefore, left carotid endarterectomy was performed. On the following day, symptoms of cerebral perfusion deficiency appeared due to occlusion of the left carotid artery. The stenotic origin of the left common carotid artery and the suspected massive thrombus in the left carotid artery posed challenges to carotid revascularization. Therefore, left subclavian artery stenting for the subclavian steal phenomenon was determined to be the best option for restoring cerebral blood flow to the whole brain. Her symptoms improved after the procedure, and the postprocedural workup revealed improved cerebral blood flow.
CONCLUSIONS: Subclavian artery stenting is safe and may be helpful in patients with cerebral perfusion deficiency caused by intractable acute carotid occlusion coexisting with the subclavian steal phenomenon. Revascularization of asymptomatic subclavian artery stenosis is generally not recommended. However, cerebral circulatory insufficiency as a comorbidity may be worth considering.

Subclavian steal syndrome results from subclavian artery stenosis that results in retrograde blood flow through the ipsilateral vertebral artery. Rarely, this retrograde flow can affect the vertebrobasilar junction and cause vertebrobasilar insufficiency, ischemia, and even aneurysm formation. We describe a unique presentation of a vertebrobasilar aneurysm presenting with subarachnoid hemorrhage in the setting of subclavian steal syndrome. The subclavian stenosis was endovascularly managed, with complete resolution of both retrograde flow and the dissection itself. Reestablishment of native flow mechanics in the subclavian artery may treat aneurysms at the vertebrobasilar junction, potentially eliminating the need for further interventions.

Early recognition and diagnosis of subclavian steal syndrome are vital to avoid unnecessary investigations and ensure appropriate management. This case highlights the significance of comprehensive evaluation, including bilateral blood pressure measurement, in patients with unilateral symptoms.

OBJECTIVE: Here, we report a case of the right-sided aortic arch with isolation of the left innominate artery and hypoplasia of the left internal carotid artery.
METHODS: A 42-year-old male patient underwent a whole-body computed tomography angiography (CTA) examination upon the clinical suspicion of vasculitis.
RESULTS: CTA revealed a right-sided aortic arch with the isolation of the left innominate artery and hypoplasia of the left internal carotid artery.
CONCLUSIONS: The right-sided aortic arch, with the isolation of the left innominate artery, is a scarce vascular variation that may occur with other cardiovascular anomalies such as ventricular septal defect. It can be asymptomatic or can present with symptoms of subclavian steal syndrome. Although its association with the agenesis of the left internal carotid artery has been reported, its association with the hypoplasia of the left internal carotid artery has not been reported previously to the best of our knowledge.

Erdheim-Chester disease (ECD) is a histiocytosis that infiltrates all organs, but especially large arteries such as the aorta and its branches, which become sheathed and lead to multiple stenoses or even occlusions. Subclavian steal syndrome (SSS) has not been reported in ECD. A 68-year-old female was diagnosed with ECD due to the typical sheathing of the aorta and its major branches. Five years previously, asymptomatic SSS due to stenosis of the left subclavian artery was incidentally diagnosed. In the following years, occlusion of the subclavian and left vertebral artery, and stenosis of basilar artery and right middle cerebral artery occurred. The abnormal cerebral perfusion had consequences on the perfusion of the left upper extremity and was presumably responsible for falls. Basilar and middle cerebral artery stenosis is rare in ECD and vertebral artery occlusion and double subclavian steal have not been reported in ECD. This case is the first to show that the initial manifestation of ECD can be unilateral SSS and that subclavian artery occlusion can even lead to double SSS. Patients with SSS should undergo a thorough diagnostic evaluation to detect rare causes of SSS, such as ECD.

We present a rare manifestation of a common pathology: left sided sensorineural hearing loss secondary to subclavian steal syndrome after thoracic endovascular aortic repair for complicated acute aortic dissection. We describe the vascular physiology that can result in unilateral hearing loss and provide a brief review of subclavian steal syndrome. This case report highlights the importance of avid clinical recognition of an atypical presentation of a common vascular disease.

Vascular ring is a rare congenital anomaly in which the abnormal origin of the aorta or its branches and pulmonary arteries leads to encircling and compression of the trachea and esophagus. A right aortic arch (RAA) with an aberrant left subclavian artery is one of the most common forms of vascular ring. Here, we report a case of a prenatally diagnosed vascular ring resulting from an RAA with an aberrant left subclavian artery. When the infant was 7 months of age, the development of noisy breathing prompted further evaluation with cardiac magnetic resonance imaging that showed an atretic left subclavian artery associated with collateral retrograde flow from the left vertebral artery to the distal portion of the subclavian artery. Our findings indicate that an untreated RAA with an aberrant left subclavian artery may be associated with an increased risk of developing subclavian artery steal syndrome.

Introduction Subclavian steal syndrome is a phenomenon of arterial flow reversal secondary to occlusive disease in proximal subclavian arteries, occasionally resulting in neurologic sequelae. Case Presentation The authors present the case of a 67-year-old man with stroke risk factors and a history of receiving head and neck radiation therapy who developed subclavian steal physiology leading to a transient ischemic attack and posterior circulation stroke. He was medically optimized without substantial progression or recurrence of disease. Conclusion This case illustrates a case of vertebrobasilar transient ischemic attack and posterior circulation stroke from subclavian steal syndrome in the setting of prior radiation therapy manifesting as extremity weakness and discoordination. Further research on therapeutic radiation dosages and subsequent incidence of arterial disease which could contribute to subclavian steal syndrome is necessary.

The prevalence of subclavian steal (defined as retrograde/bidirectional vertebral artery flow) in the general population and in patients undergoing cerebrovascular duplex ultrasound (CDUS) examinations is variable. This is the largest study to date to analyze the incidence of duplex-suggested subclavian steal in 5615 CDUS examinations over a 1-year period and to examine its clinical implications.
All consecutive CDUS examinations performed over a 1-year period were analyzed for the presence of subclavian steal. Indications of testing, presence of posterior cerebral circulation/subclavian steal symptoms, and any interventions for subclavian steal were analyzed.
A total of 171 of 5615 (3.1%) CDUS examinations were found to have subclavian steal (duplex-suggested). One hundred seventeen (2.1%) had retrograde flow and 54 (1%) had bidirectional flow. Of 171, 104 (60.8%) were left sided. Indications for CDUS were post-carotid endarterectomy/carotid artery stenting surveillance in 39 patients (22.8%), surveillance for progression of carotid stenosis in 76 patients (44.4%), transient ischemic attack/stroke in 26 patients (15%), asymptomatic screening/carotid bruit in 18 patients (10.5%), and isolated posterior cerebral circulation symptoms in 12 patients (7%). A total of 63% patients had associated >50% carotid stenosis. The mean arm Doppler pressure gradient was 32.2 mm Hg for asymptomatic patients vs 37 mm Hg for patients with posterior circulation symptoms (P = .3254). There were significant differences between the mean systolic arm pressure for patients with retrograde vs antegrade vs bidirectional flow (105 mm Hg vs 146 mm Hg vs 134 mm Hg, respectively, P < .0001). All patients with retrograde flow had >50% subclavian stenosis or occlusion (100 of 117 had subtotal/total occlusion) except for one patient. Meanwhile, 52 of 54 patients with bidirectional flow had >50% subclavian stenosis (6 of 54 with subtotal/total occlusion), whereas two patients were normal/<50% stenosis (P < .0001). Overall, 26 of 171 patients (15.2%) had interventions for disabling symptoms. Eleven of 26 of all interventions were for disabling arm claudication, and only 10 of 171 patients (5.8%) were intervened for disabling posterior circulation symptoms with complete resolution of symptoms in all except one. At a late follow-up with a mean of 18 months (range: 1-37 months), there was no late major stroke with only two lacunar infarcts (not subclavian steal related). There were also seven late deaths, none stroke related.
The incidence of subclavian steal in patients who undergo CDUS is relatively rare. Most of these patients are asymptomatic and can be treated conservatively, and only a few may need intervention for disabling symptoms with good symptom resolution.