ST-Segment elevation acute myocardial infarction due to severe hypotension and proximal left subclavian artery stenosis in a prior coronary artery bypass graft patient

Proximal subclavian artery stenosis may result in cardiac ischemia in coronary artery bypass graft patients with internal mammary grafts. We report a case of acute anterior myocardial infarction in such a patient who developed severe systemic hypotension. Symptoms and electrocardiographic changes resolved after proximal left subclavian artery stenting. Subclavian angiography should be considered in all prior coronary artery bypass graft patients with internal mammary grafts undergoing coronary angiography.     

Screening for subclinical subclavian artery stenosis before coronary artery bypass grafting: Should we do it?

Atherosclerotic subclavian artery disease is detected in about 5% of patients referred for coronary artery bypass (CABG) surgery. The internal mammary artery, a branch of the subclavian artery, is the most frequently utilized graft to restore coronary circulation because of its longevity. Stenosis or occlusion of the subclavian artery can cause retrograde blood flow in the ipsilateral internal mammary artery, known as “steal,” compromising coronary circulation supplied by the graft. Steal may be asymptomatic or may result in symptoms of myocardial ischemia. Symptomatic subclavian artery stenosis post bypass is referred to as coronary subclavian steal syndrome post‐CABG. The incidence is not well defined, and the benefits of screening patients referred for CABG are not known. Despite the various modalities available to detect subclavian artery stenosis, current guidelines fail to provide guidance about screening high‐risk patients for this entity. Detection of subclavian artery disease prior to CABG can reduce complications posed by post‐mammary artery graft cardiac ischemia. This review discusses the utility of preoperative subclavian artery screening prior to CABG.     

Screening for subclavian artery stenosis in patients who are candidates for coronary bypass surgery.

We prospectively evaluated 59 patients who were deemed candidates for coronary bypass surgery after coronary artery angiography for subclavian artery narrowing, which could compromise the ipsilateral internal thoracic artery graft. Bilateral arm blood pressure (BP) measurements, auscultation for supraclavicular or cervical bruits, and questioning about cerebrovascular ischemic symptoms were compared to brachiocephalic-subclavian arteriography. One neurologic complication occurred during arteriography. An upper extremity BP difference of > or = 15 mm Hg identified all patients with > or = 50% subclavian artery narrowing. We recommend brachiocephalic-subclavian arteriography only in patients with abnormal noninvasive screening for subclavian stenosis, not routinely.     

Successful stenting of total left subclavian artery occlusion post-coronary artery bypass graft surgery using dual left vertebral artery and left internal mammary artery protection

We report on a 68-year-old male patient (smoker, chronic obstructive pulmonary disease, diabetic for 25 years) who was admitted with acute pulmonary edema 5 months after undergoing coronary artery bypass grafting (left internal mammary artery to left anterior descending artery, saphenous vein graft to posterior descending artery, and sequential saphenous vein graft to obtuse marginal artery). He had no cardiac enzyme leakage and his left ventricular ejection fraction was > 50% on 2-dimensional echocardiography. He proved to have total calcific left subclavian artery occlusion and retrograde flow in both his left internal mammary artery and his left vertebral artery upon left subclavian angiography performed through the left brachial approach. Angiographic vertebral and coronary-subclavian steals were both supported with clinical manifestations. The patient underwent successful stenting to his left subclavian artery using dual protection to his left vertebral artery with filter protection device and to his left internal mammary artery using simple balloon inflation at its mouth before and after each subclavian artery angioplasty step. Three months later, the patient was free from any cardiac or neurologic complaints.     

Coronary subclavian steal syndrome after internal mammary artery bypass grafting. A cause of severe postoperative recurrent myocardial ischemia

A 65-year-old underwent a triple bypass: internal artery mammary-descending coronary artery, aorta diagonal-lateral coronary (sequential). Three weeks later he started to have severe angina pectoris with ST depression in anterior EKG leads. A left transradial coronary angiography was performed. The examination showed a total occlusion of the left subclavian artery 2 cm after the aortic arch and a retrograde flow in the internal mammary artery (IMA). Via transfemoral approach, angiography showed the patency of the aorto-veinous sequential graft and a retrograde flow through anastomosis in the left mammary artery. The patient underwent a reimplantation of the IMA on the brachiocephalic artery. One month later the patient is doing well without chest pain. A coronary subclavian steal syndrome should be suspected in case of recurrent ischaemia after IMA bypass, particularly if there is more than 20 mmHg systolic pressure differential between the arms. Left transradial approach achieved diagnostic in case of total left subclavian artery occlusion.     

Subclavian-coronary steal through a LIMA-to-LAD bypass graft

Eighteen months after coronary artery bypass grafting with a left internal mammary artery (LIMA) graft, a 58-year-old woman had a change in the character of her angina to include pain in the left arm, especially with upper extremity work, culminating in an episode of prolonged rest pain. Cardiac catheterization revealed retrograde flow through the LIMA graft to the subclavian artery and stenosis of the left subclavian artery at its origin from the aorta. Restoration of antegrade flow through the LIMA graft to the coronary arteries was achieved by a carotid-subclavian bypass resulting in a resolution of symptoms. The evaluation of recurrent angina after LIMA bypass grafting should exclude the possibility of subclavian artery stenosis as well as disease of the native and graft coronary anatomy.     

A uncommon cause of angina during upper limb exercise.

Subclavian artery stenosis or occlusion may be a cause of myocardial ischemia in patients treated using an internal mammary artery graft. Subclavian stenosis may cause myocardial ischemia during arm exercise by a coronary-subclavian steal phenomenon, with flow inversion in the graft from the coronary tree to the left subclavian artery. We here describe a case of a patient developing left subclavian occlusion after coronary artery bypass grafting with the left internal mammary artery. The lesion was successfully treated with a carotid-subclavian bypass. The article underscores the importance of an early diagnosis (possibly before bypass surgery) and discusses possible treatments. Percutaneous interventions with stent implantation appear the treatment of choice, but surgery has an important role in case of total occlusion.     

超声判断锁骨下动脉在冠状动脉旁路移植术应用的价值

目的:探讨冠状动脉旁路移植(CABG)术前常规超声检查锁骨下动脉的价值。方法:超声检查拟CABG术患者1546例共3092条锁骨下动脉,分析锁骨下动脉狭窄及同侧椎动脉、乳内动脉的血流频谱情况,发现锁骨下动脉中度以上狭窄时以血管造影为金标准,评价椎动脉及乳内动脉逆流诊断锁骨下动脉狭窄的价值。结果:103例患者(124条锁骨下动脉)存在锁骨下动脉起始段中度以上狭窄,狭窄发生率为6.7%。锁骨下动脉狭窄侧椎动脉逆流51条,无逆流73条,余锁骨下动脉无狭窄侧椎动脉均无逆流;锁骨下动脉狭窄侧乳内动脉逆流11条,无逆流113条,余锁骨下动脉无狭窄侧乳内动脉均无逆流。以椎动脉逆流诊断同侧锁骨下动脉狭窄的敏感性为41.1%,特异性为100%,ROC曲线下面积为0.706;以乳内动脉逆流诊断同侧锁骨下动脉狭窄的敏感性为8.87%,特异性为100%,ROC曲线下面积为0.544。结论:根据椎动脉及乳内动脉逆流诊断同侧锁骨下动脉狭窄的价值均较低,常规超声检查锁骨下动脉对指导CABG术桥血管选择避免出现冠状动脉锁骨下动脉窃血综合征是非常重要的。     

A further word of caution before using the internal mammary artery for coronary revascularization in patients with severe peripheral vascular disease!

Objectives: To characterize the clinical and angiographic characteristics of patients with collateralization from the internal mammary artery to the iliac artery. Background: The use of the internal mammary arteries for coronary revascularization has become the standard of care in coronary artery bypass grafting (CABG). However, in patients with aortoiliac disease, the internal mammary arteries may become a major collateral route to the lower extremities. Methods: A case series of 15 patients admitted for diagnostic coronary angiography were retrospectively identified, who were observed to have collateral flow from one or both internal mammary artery(ies) to an occluded or stenotic iliac artery. Results: The mean age was 63.2 ± 11.2 years; eight were men (53.3%). Coronary angiography was done as a perioperative evaluation for peripheral vascular surgery in three patients (20%) and was done because of cardiac symptoms or a positive thallium scan in 12 (80%). The finding that the mammary artery collateralized the iliac artery led to major treatment changes in all patients, seven (46.6%) who required CABG. In five patients (33%), use of one or both internal mammary artery(ies) for coronary grafts was avoided. CABG was deferred in one patient, whereas in another, percutaneous intervention in both iliac arteries preceded CABG using both mammary arteries. There was no incidence of postoperative acute lower extremity ischemia. Conclusions: Selective angiographic visualization of the internal mammary artery is an essential part of the preoperative evaluation in patients with severe peripheral vascular disease undergoing CABG. © 2009 Wiley‐Liss, Inc.     

Late occlusion of the subclavian artery proximal to mammary bypass

We report the cases of two patients with an occlusion of the left subclavian artery several years after left internal mammary bypass of the anterior interventricular artery. The effect on the myocardium was only apparent after scintigraphy in one case, and was clinical in the second with angina pain on exertion of the upper limb. Re-implantation of the subclavian artery in the common carotid relieved the signs of myocardial ischaemia. While the internal mammary artery is the conduit of choice for coronary revascularisation because it is not affected by atheromatous lesions, this does apply to the proximal subclavian artery. Stenosis or occlusion here can entail ischaemia in the revascularised myocardial territory. Regular clinical and ultrasound surveillance can detect these lesions.     

A very unusual origin of left subclavian artery

The left internal mammary artery, a branch of the left subclavian artery, is the most commonly used arterial graft during coronary artery bypass grafting. Although extremely rare, an abnormal origin of left subclavian artery may lead to a difficult coronary angiography procedure or result in a catastrophic complication if iatrogenically occluded during a stent-graft repair of thoracic aneurysm. We present a case of an unusual anomalous origin of the left subclavian artery, which was discovered during a diagnostic coronary angiography.     

Complex right subclavian artery dissection during diagnostic cardiac catheterization

Vascular complications are important and unfortunate sequelae of cardiac catheterization. We report a case of complex right subclavian artery dissection following attempted diagnostic cardiac catheterization of a right internal mammary artery (RIMA) coronary bypass graft. Subsequent dissection of the right subclavian artery involved the origin of the right vertebral and internal mammary arteries, as well as producing critical right upper limb ischemia. The anatomy dictated that therapy consist of conservative management of the proximal dissection involving the vertebral artery and the RIMA graft origins, with endovascular stent deployment at the distal site of the vessel occlusion. This example reinforces the need for prompt diagnosis and management of vascular complications, and emphasizes the need for available, appropriate skills relevant to the peripheral vascular interventions.     

Transradial access in an occluded radial artery: new technique

Radial access is considered clearly impossible in patients who develop radial artery occlusion after a transradial procedure. Radial artery occlusion also prohibits an ipsilateral transulnar approach. For patient subsets such as those with dialysis access in the other upper extremity or an occluded left radial artery with left internal mammary artery bypass grafts, switching to the transfemoral approach becomes inevitable. In some instances, the femoral access is also not an option due to severe aortoiliac disease. We describe a technique that allows the operator to access the proximal circulation from the occluded radial artery.     

Percutaneous revascularization of the “unprotected” left main during acute myocardial infarction: “Dare to struggle! Dare to Win!”

Knowing the location of the vertebral and the internal mammary artery ostia is crucial during proximal subclavian artery percutaneous intervention to prevent inadvertent injury to either artery. We report a case of severe proximal left subclavian artery stenosis in a patient with a three‐vessel disease referred to coronary artery bypass graft surgery. Retrograde angiography via left radial access allowed visualization of the left internal mammary artery and the left vertebral artery ostia and placement of a Filterwire in the left vertebral artery. The proximal left subclavian artery was successfully stented without complications. Debris was retrieved in the Filterwire. © 2009 Wiley‐Liss, Inc.     

A case of Coronary-Subclavian Steal Syndrome

Surgical bypass of left coronary artery disease using the internal mammary artery (IMA) as a conduit is standard practice. Adequate blood supply to the IMA is dependent on normal flow in the subclavian artery. Stenosis of the subclavian can impair coronary supply from the internal mammary artery. This may create a steal syndrome whereby the left arm may rob the coronary system of flow especially during arm exercise. In the present report a case of angina with left coronary system steal via an internal mammary graft due to atherosclerotic subclavian stenosis. Successful treatment of the anginal symptoms by native coronary stenting is described.     

Subclavian Artery Disease: Diagnosis and Therapy

The diagnosis of brachiocephalic disease is often overlooked. Symptoms include arm claudication and vertebrobasilar insufficiency. In patients who have had the use of the internal mammary artery for coronary bypass surgery, the development of symptoms of myocardial ischemia should alert the clinician to the possibility of subclavian artery stenosis. Also, in patients who have had axillofemoral bypass, lower-extremity claudication may occur. Recognition involves physical examination and accurate noninvasive testing. Endovascular therapy has proven to be effective in alleviating symptoms in properly selected patients.     

Interventional treatment of the left subclavian in 2 patients with coronary steal syndrome

In patients with history of coronary artery disease angina pectoris is usually attributed to the progression of atherosclerotic lesions. However,in patients with previous coronary artery bypass graft operation(CABG) using internal mammary artery grafts,great vessel disease should also be considered. Herein we present two patients with history of CABG whose symptoms were suspicious for coronary ischemia. During cardiac catheterization reverse blood flow was observed from the left artery disease to the left internal mammary artery(LIMA) graft in both cases. After angioplasty and stent implantation of the left subclavian artery antegrade flow was restored in the LIMA grafts and both patients had complete resolution of symptoms.     

Stenting of the left carotid artery to relieve anginal symptoms.

Stenting of the carotid artery is usually performed either to prevent an acute neurologic event or to treat episodes of recurrent transient ischemic attacks. Occasionally, it may be performed for other indications. We describe the case of a patient with prior coronary artery bypass grafting using a left internal mammary arterial graft, in addition to left carotid artery to left subclavian artery bypass for symptomatic left subclavian stenosis, who subsequently underwent left common carotid artery stenting to relieve anginal symptoms.     

Stent PTA in secondary symptomatic proximal subclavian artery obstruction

Stent-PTA of secondary symptomatic proximal subclavian artery stenosis In comparison with conventional surgical revascularisation, percutaneous transluminal angioplasty (PTA) is an alternative treatment for short stenoses or occlusions involving the origin of the subclavian artery. If there is clinical suspicion of subclavian artery obstruction (e.g. blood pressure difference in both arms), digital subtraction angiography of the aortic arch and upper limb should be performed prior to creating radial haemodialysis shunts or coronary bypass crafting involving the internal mammary artery. PTA and stenting can be successfully carried out in symptomatic secondary proximal subclavian artery stenosis, e.g. in radial haemodialysis fistulas with distal ischaemia.     

Evaluation of coronary subclavian steal syndrome using sestamibi imaging and duplex scanning with observed vertebral subclavian steal

Coronary subclavian steal is defined as retrograde blood flow from the myocardium through the internal mammary artery graft, secondary to a proximal subclavian artery stenosis. The incidence of this syndrome in patients undergoing internal mammary artery grafts for coronary artery bypass is estimated to be 0.44%. Angiography remains the definitive diagnostic test for confirming this condition. We describe a noninvasive method for evaluating coronary subclavian steal syndrome in a 57-year-old man, with a 50-55% subclavian stenosis confirmed by angiography. Noninvasive evaluation using duplex scanning demonstrated normal vertebral artery blood flow. Technetium 99m-sestamibi (99mTc) imaging confirmed a fixed anterolateral defect. When left-arm isometric exercise was employed, retrograde vertebral artery blood flow was observed by Doppler imaging. A repeat 99mTc-sestamibi study documented an increase in tracer distribution in the anterolateral defect confirming reperfusion of the myocardium through the left internal mammary artery graft. The use of duplex scanning and 99mTc-sestamibi may serve as an adjunct in evaluating coronary subclavian steal syndrome as well as documenting transient vertebral subclavian steal in this patient population.