Non-invasive diagnosis of coronary-subclavian steal: role of the Doppler ultrasound

Symptomatic subclavian steal syndrome: Report of four Moroccan cases and literature review

Introduction

Subclavian steal syndrome (SSS) is the hemodynamic phenomenon of blood flow reversal in the vertebral artery due to significant stenosis or occlusion of the proximal ipsilateral subclavian artery.

Materials and methods

Four patients with subclavian steal syndrome were treated in our center. Percutaneous radial approach was used for angioplasty, primary stenting of subclavian artery was performed, surgical techniques in particular carotid-subclavian bypass and carotid-subclavian transposition were used.

Results

We report the cases of four patients, three of which are male, with an average age of 60 years. All of them were symptomatic. Diagnosis was made by duplex ultrasound, supplemented by CT-angiography and arteriography. Endovascular treatment was attempted in all four patients, which was successful in two patients, who underwent primary stenting, and failed for the two others, for whom surgical treatment was considered. One had a subclavio-carotid bypass graft with a polytetrafluorethylene (PTFE) prosthesis and the other had a subclavio-carotid transposition. The technical results were satisfactory in all patients with symptoms resolution. The postoperative evolution was without notable complications and the postoperative checkups were satisfactory.

Discussion

There are excellent screening tools and effective medical therapies which can be instituted if the SSS is diagnosed early. When the need for revascularization arises, percutaneous modalities are favored given their proven long-term efficacy, decreased morbidity and mortality, and cost-effectiveness. Nevertheless, large, prospective, randomized and controlled trials are needed to compare the long-term patency rates between the endovascular and surgical techniques.

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SSS is caused by the reversal of blood flow in the vertebral artery.

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Doppler ultrasound is the ultimate screening tool for diagnosis.

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Treatment of symptomatic SSS is always indicated.

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Endovascular approach is the first-line treatment.

Acute coronary syndrome following arteriovenous fistula creation in a post CABG patient: A steal phenomenon from coronary artery to subclavian artery

A 70-year-old man with a history of coronary artery bypass grafting 15 years back and arteriovenous (AV) fistula creation in the left arm 1 month back presented with acute coronary syndrome (ACS). He had not received dialysis before his referral. We felt the most likely etiology for these complaints was increased cardiac oxygen demand from an increased cardiac output related to the newly formed left AV fistula. Coronary angiography was done to detect any significant stenosis in the native or grafted vessels. This revealed that the left subclavian artery was totally occluded in the ostioproximal segment and the coronary arteries did not have occlusions to explain the ACS setting. CT angiography confirmed the angiographic findings of the totally occluded left subclavian artery followed by a well-developed and patent left internal mammary artery to left anterior descending artery. This led to the consideration of a steal syndrome from the coronary artery by the subclavian artery distal to the occlusion. A successful percutaneous endovascular intervention on the left subclavian artery occlusion was performed. Subsequently, the patient became asymptomatic and experienced a dramatic increase in left ventricular ejection fraction.

Neuro-ultrasonography

Transcranial Doppler ultrasonography (TCD) is a noninvasive, bedside, portable tool for assessment of cerebral hemodynamics. Modern TCD head frames allow continuous hands-free emboli detection for risk stratification and assessment of treatment efficacy in several cardiovascular diseases. Identifying a focal stenosis, arterial occlusion, and monitoring the treatment effect of intravenous tissue plasminogen activator can easily be accomplished by assessing TCD waveforms and determining prestenotic and poststenotic mean flow velocities. TCD is an excellent screening tool for vasospasm in aneurysmal subarachnoid hemorrhage. The use of intraoperative TCD during carotid endarterectomy and stenting allows optimal intraoperative hemodynamic management. Other applications are also discussed.

Endovascular treatment of coronary subclavian steal syndrome complicated with STEMI and VF: A case report and review of the literature

Endovascular treatment of coronary subclavian steal syndrome is usually successful and safe. However, it might be lethally complicated, such as our case of STEMI and ventricular fibrillation during stent deployment. Early diagnosis of subclavian stenosis, intermittent dilations of balloons during stent deployment, and choosing the accurate stent size are suggested to avoid such complications.

Clinical significance of reversal of flow in the vertebral artery identified on cerebrovascular duplex ultrasound

BACKGROUND

Reversal of flow in the vertebral artery (RFVA) is an uncommon finding on cerebrovascular duplex ultrasound examination. The clinical significance of RFVA and the natural history of patients presenting with it are poorly understood. Our objective was to better characterize the symptoms and outcomes of patients presenting with RFVA.

METHODS

A retrospective review was performed of all cerebrovascular duplex ultrasound studies performed at our institution between January 2010 and January 2016 (N = 2927 patients). Individuals with RFVA in one or both vertebral arteries were included in the analysis.

RESULTS

Seventy-four patients (74/2927 patients [2.5%]) with RFVA were identified. Half of the patients were male. Mean age at the time of the first ultrasound study demonstrating RFVA was 71 years (range, 27-92 years); 78% of patients had hypertension, 28% were diabetic, and 66% were current or former smokers. Indications for the ultrasound examination were as follows: 44% screening/asymptomatic, 7% anterior circulation symptoms, 20% posterior circulation symptoms, 28% follow-up studies after cerebrovascular intervention, and 5% upper extremity symptoms. At the time of the initial ultrasound examination, 21 patients (28%) had evidence of a prior carotid intervention (carotid endarterectomy or carotid stenting), 21 patients had evidence of moderate (50%-79%) carotid artery stenosis (CAS) in at least one carotid artery, and 12 patients (16%) had evidence of severe (>80%) CAS. Of the 15 patients presenting with posterior circulation symptoms, 11 (73%) had evidence of concomitant CAS. In contrast, 22 of the 59 patients (37%) without posterior circulation symptoms had duplex ultrasound findings of CAS (P = .01). The mean duration of follow-up was 28 ± 22 months. Follow-up data were available for 63 patients (85%), including the 15 patients who presented with posterior circulation symptoms. Of these 15 patients, 5 underwent subclavian artery revascularization, including balloon angioplasty and stenting in 4 patients and open/hybrid revascularization in 1 patient. Five individuals were awaiting intervention. Three patients underwent carotid endarterectomy for CAS, with resultant improvement in posterior circulation symptoms. Finally, one patient was deemed too high risk for intervention, and one patient was found to have an alternative cause for symptoms. The remaining 59 patients continued to be asymptomatic during follow-up. One patient progressed to vertebral artery occlusion, and six patients had progression of CAS.

CONCLUSIONS

Symptomatic RFVA responds well to intervention, including subclavian artery stenting and carotid intervention in patients with CAS. The majority of patients with this finding are asymptomatic at the time of presentation. Although progression of vertebral artery disease is rare, these patients may benefit from monitoring for progression of CAS with surveillance ultrasound.

Axillo-femoral bypass steal due to subclavian artery stenosis

Subclavian artery stenosis can cause a flow reversal-so-called steal-not only in the ipsilateral vertebral artery, but also in the internal mammary artery in patients with a history of coronary-artery bypass grafting. Subclavian artery stenosis is also associated with peripheral artery disease elsewhere. We report a novel finding of axillo-femoral bypass steal due to subclavian artery stenosis identified by vascular ultrasonography.

Coronary subclavian steal syndrome

PURPOSE OF REVIEW

Coronary subclavian steal syndrome (CSSS) is the reversal of blood flow in an internal mammary artery bypass graft that results in coronary ischemia. CSSS is an uncommon but treatable cause of coronary ischemia. In this review, we highlight the historical background and epidemiology of CSSS, common clinical presentations, diagnosis of CSSS and management strategies for relieving ischemia. We also present a case report to illustrate the complexity of CSSS and percutaneous management using current technology.

RECENT FINDINGS

Most commonly, CSSS results from atherosclerotic stenosis of the subclavian artery and occurs in 2.5-4.5% of patients referred for coronary artery bypass grafting (CABG). All patients referred for CABG should have bilateral noninvasive brachial blood pressures checked to screen for the underlying subclavian stenosis. A review of 98 case reports with 128 patients demonstrated a diverse clinical presentation of CSSS, including acute myocardial infarction, unstable angina and acute systolic heart failure. Resolution of CSSS symptoms has been reported with both surgical and percutaneous revascularization. Long-term patency with either revascularization strategy is excellent. Percutaneous revascularization is largely considered the first-line therapy for CSSS and can be safely performed prior to CABG to prevent CSSS.

SUMMARY

CSSS should be suspected in patients presenting with angina, heart failure or myocardial infarction after CABG. Successful amelioration of CSSS symptoms can be safely and effectively performed via percutaneous revascularization.

Subclavian steal syndrome presenting as recurrent pulmonary oedema associated with acute left ventricular diastolic dysfunction

Subclavian steal syndrome typically presents as angina in patients with internal mammary artery grafts. Atypical clinical presentations have been rarely described. We report an unusual case of subclavian steal syndrome presenting as pulmonary oedema with acute left ventricular diastolic dysfunction and preserved ejection fraction in a patient with internal mammary artery graft and severe stenosis of the proximal left subclavian artery. After successful angioplasty and stenting of subclavian artery, the patient remained asymptomatic for six months, but then experienced acute diastolic dysfunction and recurrent pulmonary oedema associated with critical subclavian in-stent restenosis with stent deformation. This report points out that, in patients with internal mammary-to-LAD grafts, subclavian steal syndrome may present as acute left ventricular diastolic dysfunction and pulmonary oedema even in the presence of normal ejection fraction.

A review of subclavian steal syndrome with clinical correlation

Subclavian 'steal' phenomenon is a function of the proximal subclavian artery (SA) steno-occlusive disease, with subsequent retrograde blood flow in the ipsilateral vertebral artery (VA). The symptoms from the compromised vertebrobasilar and brachial blood flows constitute the subclavian steal syndrome (SSS), and include paroxysmal vertigo, drop attacks and/or arm claudication. Once thought to be rare, the emergence of new imaging techniques has drastically improved its diagnosis and prevalence. The syndrome, however, remains characteristically asymptomatic and solely poses no serious danger to the brain. Recent studies have shown a linear correlation between increasing arm blood pressure difference with the occurrence of symptoms. Atherosclerosis of the SA remains the most common cause. Doppler ultrasound is a useful screening tool, but the diagnosis must be confirmed by CT or MR angiography. Conservative treatment is the initial best therapy for this syndrome, with surgery reserved for refractory symptomatic cases. Percutaneous angioplasty and stenting, rather than bypass grafts of the subclavian artery, is the widely favored surgical approach. Nevertheless, large, prospective, randomized, controlled trials are needed to compare the long-term patency rates between the endovascular and open surgical techniques.