Fistulous connection between internal mammary graft and pulmonary vasculature after coronary artery bypass grafting: a rare cause of continuous murmur

A 58-year-old male who had undergone coronary artery bypass grafting (CABG) using left internal mammary artery and a sequential saphenous vein graft 2 years ago presented with new onset angina. His initial physical examination revealed an unexpected continuous murmur over the left sternal border, and two-dimensional echocardiography has failed to identy the cause. Cardiac catheterization then performed and revealed patent left internal mammary artery and saphenous vein grafts. Besides, selective injection of the left internal mammary artery graft also showed a fistula formation between left internal mammary artery graft and pulmonary vasculature of the left upper lobe. He was managed conservatively because of the severely diseased left anterior descending artery distal to internal mammary artery anastomosis and low pulmonary artery pressure. The development of fistulous connection between internal mammary artery and pulmonary vasculature is an extremely rare complication following CABG. Patients with such fistulae usually present with chest pain due to coronary steal syndrome. A new heart sound, especially a continuous murmur, may be detected during physical examination. Surgical correction is indicated in the event of refractory angina, growing fistula causing heart failure or endarteritis. Otherwise, a conservative approach with instruction of the patient for prophylactic precautions of subacute bacterial endocarditis may be recommended for asymptomatic patients.     

Claudication pain in the left arm of a coronary artery bypass graft patient using crutches: Coronary subclavian steal syndrome - a case report

A 77-year-old male former smoker with hypercholesterolemia and diabetes, who underwent coronary artery bypass graft surgery three years before admission and right carotid endarterectomy four years before admission, presented with recent-onset exertional chest pain. His medical history revealed that the chest pain was preceded by gradually worsening exertional claudication pain in his left arm when he was using crutches. The chest pain was similar to the pain he experienced before the coronary artery bypass graft surgery was performed. Coronary angiography and bypass graft imaging showed significant stenosis of the left subclavian artery proximal to the origin of the left internal mammary artery bypass, decreased flow in the left internal mammary artery with partial retrograde filling from the left anterior descending artery, and severe narrowing of the left vertebral artery with preserved centrifugal flow. Percutaneous stent implantation into the left subclavian artery was performed together with proximal balloon angioplasty of the left vertebral artery. The patient has been symptom free since the stent implantation.     

Sequential internal mammary artery bypass for multiple coronary stenoses

Long-term studies (10 years) show a 50 per cent patency rate of saphenous vein autograft and 95 per cent patency rate of internal mammary artery coronary bypass grafts. In some situations (after saphenous vein stripping, varicose and fibrotic veins) it is not possible to use venous grafts and the internal mammary artery has to be used. However, the internal mammary artery is usually only used for revascularisation of the left anterior descending artery. Sequential internal mammary artery bypass is a technique which can be used for revascularizing the left anterior descending artery. Seven men aged 44 to 68 years (average 55 years) were operated between November 1983 and February 1985. These patients had clinically stable (4 cases) or instable (3 cases) angina. Two patients had previously undergone bilateral saphenous vein stripping and one patient a terminal anastomosis on the left anterior descending and a latero-lateral anastomosis on the diagonal artery. Three patients had an associated venous bypass graft and one patient also underwent aortic valve replacement. There were no cases of postoperative myocardial infarction. Five control angiographies were carried out during the first postoperative month. In 4 patients the internal mammary graft ant the latero-lateral and termino-lateral anastomoses were patent. In the other case, the latero-lateral anastomosis and the diagonal artery was occluded but the internal mammary graft and the termino-lateral anastomosis on the left anterior descending artery were patent. The average follow-up period is now 18 months: there have been no recurrences of chest pain or any ECG changes. These results show that internal mammary artery bypass grafting is a delicate procedure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Early postoperative occlusion of a left internal mammary artery bypass graft with subsequent restoration of patency.

Total occlusion of a left internal mammary artery (LIMA) bypass graft is a rare complication, and reversal of a documented occlusion has not been reported. This is a case of an early postoperative occlusion of a LIMA graft that was found to be patent 4 months later. A patient with three vessel disease (including a moderate lesion in the proximal left anterior descending artery and a severe lesion in its mid-portion) underwent coronary artery bypass grafting with a LIMA to the mid-left anterior descending artery (LAD) and saphenous vein grafts to the right coronary and left circumflex arteries. Coronary angiography 3 months after surgery revealed a totally occluded internal mammary artery and saphenous vein grafts. The patient then underwent a successful angioplasty of the more distal lesion in the LAD. She subsequently returned with recurrent angina. Repeat coronary angiography revealed rapid progression of the disease in the proximal LAD with the more distal angioplasty site being widely patent. Selective arteriography of the internal mammary artery at that time revealed a patent vessel. Thus, the internal mammary graft is a physiologically active conduit that is dependent on flow dynamics. Competitive flow through the nonobstructive native LAD in combination with impedance of flow through the internal mammary artery due to a severe lesion in the LAD distal to the anastomosis led to a functionally occluded LIMA. When the obstruction in the proximal LAD progressed and the distal obstruction was successfully angioplastied, the flow dynamics in the internal mammary improved, allowing for its dilatation and restoration of patency.(ABSTRACT TRUNCATED AT 250 WORDS)     

Early postoperative occlusion of a left internal mammary artery bypass graft with subsequent restoration of patency

Total occlusion of a left internal mammary artery (LIMA) bypass graft is a rare complication, and reversal of a documented occlusion has not been reported. This is a case of an early postoperative occlusion of a LIMA graft that was found to be patent 4 months later. A patient with three vessel disease (including a moderate lesion in the proximal left anterior descending artery and a severe lesion in its mid-portion) underwent coronary artery bypass grafting with a LIMA to the mid-left anterior descending artery (LAD) and saphenous vein grafts to the right coronary and left circumflex arteries. Coronary angiography 3 months after surgery revealed a totally occluded internal mammary artery and saphenous vein grafts. The patient then underwent a successful angioplasty of the more distal lesion in the LAD. She subsequently returned with recurrent angina. Repeat coronary angiography revealed rapid progression of the disease in the proximal LAD with the more distal angioplasty site being widely patent. Selective arteriography of the internal mammary artery at that time revealed a patent vessel. Thus, the internal mammary graft is a physiologically active conduit that is dependent on flow dynamics. Competitive flow through the nonobstructive native LAD in combination with impedance of flow through the internal mammary artery due to a severe lesion in the LAD distal to the anastomosis led to a functionally occluded LIMA. When the obstruction in the proximal LAD progressed and the distal obstruction was successfully angioplastied, the flow dynamics in the internal mammary improved, allowing for its dilatation and restoration of patency. Therefore, an angiographically occluded internal mammary graft may be only functionally occluded and reversible even when the occlusion is demonstrated several days apart.     

Coronary-subclavian steal syndrome presenting with chest pain and syncope

The present case is a 68-year-old patient with complaints of chest pain and syncopal attacks during physical activity of the left arm, for the last six months. He had a coronary artery bypass graft operation 10 years ago. Angiographic examination demonstrated total occlusion of the subclavian artery. The subclavian artery was stealing blood from the left anterior descending artery via the left internal mammary artery and from the brain via the left vertebral artery, leading to the diagnosis of subclavian artery steal syndrome; a rare cause of coronary and cerebral ischaemia.     

Comparison of coronary hemodynamics in patients with internal mammary artery and saphenous vein coronary artery bypass grafts: a noninvasive approach using combined two-dimensional and Doppler echocardiography

Blood flow in bypass grafts and recipient left anterior descending coronary arteries was evaluated with combined two-dimensional and Doppler echocardiography in 15 patients with an internal mammary artery graft and in 24 patients with a saphenous vein graft. Comparative studies of coronary hemodynamics were also performed regarding these two different grafting techniques. The graft vessel was detected in 11 (79%) of 14 patients with an internal mammary artery graft and in 20 (87%) of 23 with a saphenous vein graft. The recipient left anterior descending coronary artery was detected in 10 (67%) of the former group and 17 (71%) of the latter. The blood flow patterns obtained were generally biphasic, consisting of systolic and diastolic phases with higher velocity during diastole. The maximal diastolic flow velocity in internal mammary artery grafts was much higher than that in saphenous vein grafts. In patients with an internal mammary artery graft, the flow pattern characteristics within the recipient coronary artery were quite similar to those within the arterial graft, and flow velocities within the recipient coronary artery and the arterial graft were quantitatively almost identical. This outcome may contribute to the long-term patency seen in internal mammary artery grafts. On the other hand, the flow velocity in saphenous vein grafts was fairly low throughout the cardiac cycle. Flow velocity in the recipient coronary artery in patients with a saphenous vein graft was accelerated only in early diastole. As a result, the recipient coronary artery flow pattern and velocity differed substantially from those in the saphenous vein graft.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fatal left internal mammary artery graft to subclavian vein fistula complicating dual-chamber pacemaker implantation.

We describe the case of a 75-year-old woman with an iatrogenic fistula between a left internal mammary artery graft to the left anterior descending coronary artery and the left subclavian vein that developed after implantation of a dual-chamber pacemaker.     

Percutaneous transluminal angioplasty of proximal subclavian artery stenosis after left internal mammary to left anterior descending artery bypass surgery.

A patient is described who underwent percutaneous transluminal angioplasty, through a brachial approach, of a high grade stenosis at the proximal portion of the left subclavian artery 1.5 years after coronary artery bypass grafting including left internal mammary to left anterior descending artery anastomosis. Symptoms of class IV angina, vertebrobasilar insufficiency and occupational arm claudication that developed after bypass surgery were promptly relieved after balloon dilation. Percutaneous transluminal angioplasty of the subclavian artery can be performed safely and provides an alternative to carotid-subclavian or axillary-axillary bypass surgery for treatment of internal mammary artery graft malfunction.     

10-year results of anastomoses of the left internal mammary artery to the anterior interventricular artery. Angiographic and radionuclide controls

The long term patency of left internal mammary artery graft is better than that of saphenous vein graft. The aim of this study was to determined if this high patency rate was accompanied by a satisfactory myocardial perfusion. Among 143 patients treated with an internal mammary artery graft on the left anterior descending artery between 1972 and 1976, 42 patients underwent coronary angiogram and exercise tomoscintigraphy (thallium 201) over 10 years after surgery. The left internal mammary artery was patent in 92% without any atheromatous lesions. The myocardial perfusion in the area supplied by the left anterior descending artery was normal in 74%. A slight ischemia appeared during exercise in 19% without any clinical symptoms. This long term study shows excellent anatomical results correlated with a good myocardial perfusion during exercise in most cases.     

Balloon expandable stent implantation after latrogenic arterial dissection of the left subclavian artery

A patient undergoing attempted angioplasty of a left internal mammary artery graft to left anterior descending coronary artery developed an iatrogenic dissection of the left subclavian artery, with symptoms of left arm claudication. A balloon expandable stent was inserted with an excellent angiopgraphic result. The patient has remained free of symtoms or signs of decreased arm flow, with a patent subclavian artery demonstrate on angiography 8 months later. The excellent early-to-moderate term clinical and angiographic results support the efficacy of this technical approach. © 1995 Wiley-Liss, Inc.     

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.     

Chylothorax after myocardial revascularization with the left internal thoracic artery

A 38-year-old male underwent coronary artery bypass grafting (CABG). A saphenous vein graft was attached to the left marginal branch. The left internal thoracic artery was anastomosed to the left anterior descending artery (LAD). The early recovery was uneventful and the patient was discharged on the 5th postoperative day. After three months, he came back to the hospital complaining of weight loss, weakness, and dyspnea on mild exertion. Chest X-rays showed left pleural effusion. On physical examination, a decreased vesicular murmur was detected. After six days, the diagnosis of chylothorax was made after a milky fluid was detected in the plural cavity and total pulmonary expansion did not occur. On the next day, both anterior and posterior pleural drainage were performed by videothoracoscopy, and prolonged parenteral nutrition (PPN) was instituted for ten days. After seven days the patient was put on a low-fat diet for 8 days. The fluid accumulation ceased, the drains were removed and the patient was discharged with normal pulmonary expansion.     

The internal mammary artery bypass graft: praise versus practice

Patency rates and long-term clinical results after coronary artery bypass are superior when the internal mammary artery, rather than the saphenous vein, is used as a bypass graft. Four thousand forty-seven cardiac surgeons were surveyed to assess their theoretical preference of bypass graft, in comparison to their actual practice. The 750 surgeons performing myocardial revascularization who completed the questionnaire had done approximately 122,652 coronary artery bypass operations annually. Six hundred twenty-nine (84%) listed the internal mammary artery as the graft of choice for bypassing the left anterior descending coronary artery, whereas 114 (15%) listed the saphenous vein. Only about half (56%) of the surgeons actually used the internal mammary artery commonly, however, and only 228 (30%) used it in at least 90% of their operations. In actual practice, then, the internal mammary artery is often avoided in situations where it could be used as a coronary artery bypass graft. This practice can be expected to have a negative influence on late postoperative results. (The Texas Heart Institute Journal 1987; 14:139-143)     

Evaluation of flow reserve in internal mammary artery in situ bypass

The internal mammary artery, when used as a conduit for coronary artery bypass, offers a better long-term patency and survival rate than the saphenous vein. However, concern exists that the flow through the internal mammary artery may be inadequate during periods of peak myocardial demand. This flow was investigated in 18 consecutive patients who were selected for coronary bypass of the left anterior descending artery using the internal mammary artery. All patients were evaluated post-operatively within 12 months by means of graded maximal stress test, cardiac catheterization and exercise thallium-201 scintigraphy. Significant improvement in work capacity, maximal rate-pressure product, effort angina and ECG abnormalities during exercise stress testing were observed following internal mammary artery myocardial revascularization. The patency rate for internal mammary artery grafts was 100% (vs 85% for vein grafts); during the followup period, occlusion of a saphenous vein bypass or development of a new stenosis in a native coronary artery was noted in five patients, and two patients were classified as having partial revascularization. Ischemia, demonstrated by perfusion deficits at peak stress which disappeared in the 3-hour delayed film, was documented in 7.4% (4/54) of the areas supplied by internal mammary artery grafts, compared to 31% (13/42) of the regions revascularized using saphenous vein conduits. Although this result was not statistically significant, a definite trend is suggested. We conclude that ischemia demonstrated by stress thallium scintigraphy in the post-operative period is uncommon when an internal mammary artery graft has been used. This suggests that adequate coronary flow exists at peak myocardial demand during exercise.     

Percutaneous coil closure of recanalised anomalous origin of left coronary artery from pulmonary artery

An asymptomatic boy underwent surgical correction of anomalous origin of left coronary artery from pulmonary artery (ALCAPA) with trans-pulmonary artery interruption and saphenous vein grafting to left anterior descending coronary artery. He developed a shunt through the re-canalised pulmonary artery end of the ALCAPA which was successfully embolised using a detachable PDA coil delivered into the left main coronary artery from the pulmonary artery.     

Relocation of the internal mammary artery graft in a case of coronary-subclavian steal

Reverse flow in the internal mammary artery coronary graft in the presence of subclavian stenosis is rare. We describe a 67-year-old man who 7 years after coronary artery surgery was admitted with left subclavian artery stenosis and retrograde flow in the pedicled left internal mammary artery graft. Subsequent redo triple coronary artery bypass grafts included regrafting the left internal mammary artery graft to a new vein conduit.     

Effect of acetylcholine on arterial and venous grafts and coronary arteries in patients with coronary artery disease

Endothelium-dependent vasomotor responses differ in arteries and veins. The transfer of a given vessel from a different vascular bed into the coronary circulation by grafting may affect its endothelial function. In order to evaluate the differences in endothelial function of the internal mammary artery and aortocoronary venous grafts in patients with coronary artery disease, the response to acetylcholine (ach) was examined and compared with that of native coronary arteries. Eighteen patients were examined, including eight with internal mammary artery grafts (9 days to 48 months after surgery), and 10 with saphenous vein grafts (12-96 months after surgery). Ach (70-700 nmol min-1) was infused selectively into a graft on the left anterior descending coronary artery, and the effect on vessel diameters was assessed by quantitative arteriography. In both groups 84% and 83%, respectively, of the arterial segments distal to the bypass anastomosis were contracted by ach (greater than or equal to 70 nmol min-1). The segments of both groups did not show angiographic evidence of local atherosclerosis. A complete occlusion occurred in four cases. In contrast, internal mammary artery grafts were not contracted by ach; in four of 12 segments a dilatation was observed, whereas five of 20 aortocoronary venous graft segments showed a slight reduction in lumen diameter after the highest ach dose applied. The vasoconstricting effect of ach was reversed by intracoronary nitroglycerin. By using ach as an indicator of endothelial dysfunction it is concluded that the internal mammary artery grafts maintained an intact endothelial function after surgery, whereas the coronary artery segments showed an impaired endothelium-dependent vasodilatation. Some of the venous graft segments reacted as coronary arteries did with a less pronounced cholinergic vasoconstriction. This in vivo study supports the observation of a functional superiority of internal mammary artery over saphenous vein coronary grafts.     

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.     

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.