Internal Mammary Graft Research Articles

Urgent trans‐axillary valve‐in‐valve procedure using the Edwards 16‐F expandable introducer

Transcatheter aortic valve implantation could represent an alternative option to conventional surgery in high-risk patients with degeneration of aortic bioprosthesis. Herein, we report the performance of a valve-in-valve procedure in urgent conditions and via the left axillary artery in a patient with patent left internal mammary artery coronary graft. A 23-mm Edwards Sapien(®) transcatheter valve was deployed within a 23-mm Edwards Magna Ease bioprosthesis through the novel Edwards 16-F expandable introducer. In this non-elective case, the expandable introducer allowed a safe procedure, reduced the risk of subclavian injury, and preserved the left internal mammary artery graft flow.

Two questions on bilateral internal mammary artery usage

The use of a single internal mammary graft to the left anterior descending artery has been the gold standard in surgical coronary revascularization since its introduction. However, the take-up rate of use of bilateral internal mammary arteries has been slow despite emerging evidence. This has been partly due to the worry of postoperative complications, in particular, sternal wound complications. Skeletonization of the internal mammary has been proposed as a technique that can preserve the sternal microcirculation and therefore reduce this complication. In this article, we examine the evidence comparing the skeletonization technique versus the conventional pedicled technique for harvesting the internal mammary artery.

To stent or not to stent - a challenging decision in a rare condition

Introduction: In this case we discuss the management of a patient with recurrent acute coronary syndrome due to Takayasu arteritis (TA). Case report description: In 2007, a 13-year-old Caucasian male with angina, electrocardiographic and troponin abnormalities consistent with an acute coronary syndrome, and widespread bruits, was found to have multiple arterial stenoses involving the aorta, renal and carotid arteries. The erythrocyte sedimentation rate was 32mm (0-7), C reactive protein 36 mg/L (0-7) with a mild normocytic anaemia. Coronary angiography showed triple vessel disease and he was diagnosed with TA with coronary artery involvement. Coronary artery bypass graft surgery (free left internal mammary graft to the left anterior descending artery and sequential saphenous vein graft to the intermediate and left posterolateral vessels) was performed. The patient received intensive medical therapy and angioplasty for hypertension due to bilateral renal artery stenosis. His condition continued to progress and angina recurred in 2012 with coronary angiography demonstrating occlusion of the vein graft segment to the posterolateral artery. The patient was managed medically but was diagnosed with a non-ST elevation myocardial infarction in 2013 due to occlusion of the vein graft to the intermediate. He suffered ongoing symptoms of cardiac ischaemia and after discussion with the Cardiosurgical team a decision was made to treat the diseased native right coronary artery by percutaneous coronary artery intervention (PCI) with drug eluting stents. Despite this measure the patient has experienced ongoing angina and further PCI to the ungrafted left coronary artery territories is under consideration. Discussion: TA most commonly presents in 20-30 year-old females of East Asian descent and coronary artery involvement in children is very rare. From a cardiac perspective this case highlights the challenge of managing coronary artery disease in the setting of active large vessel vasculitis. Limited data exist to guide clinicians in this setting. Whether redo cardiac surgery at age 18 would be superior to a percutaneous approach is unclear. Implications to clinical practice: 1. Our case highlights the importance of considering vasculitis in the differential diagnosis of a young patient presenting with chest pain. 2. Rare clinical scenarios can pose a management dilemma for the treating physician due to the paucity of supporting research available to direct the decision making process. Treatment strategies should be decided on a case-by-case basis and consensus opinion from the multidisciplinary team is recommended.

Long-Term Survival and Repeat Coronary Revascularization in Dialysis Patients After Surgical and Percutaneous Coronary Revascularization With Drug-Eluting and Bare Metal Stents in the United States

Few published data describe long-term survival of dialysis patients undergoing surgical versus percutaneous coronary revascularization in the era of drug-eluting stents (DES). Using United States Renal Data System data, we identified 23 033 dialysis patients who underwent coronary revascularization (6178 coronary artery bypass grafting, 5011 bare metal stents, 11 844 DES) from 2004 to 2009. Revascularization procedures decreased from 4347 in 2004 to 3344 in 2009. DES use decreased by 41% and bare metal stent use increased by 85% from 2006 to 2007. Long-term survival was estimated by the Kaplan-Meier method, and independent predictors of mortality were examined in a comorbidity-adjusted Cox model. In-hospital mortality for coronary artery bypass grafting patients was 8.2%; all-cause survival at 1, 2, and 5 years was 70%, 57%, and 28%, respectively. In-hospital mortality for DES patients was 2.7%; 1-, 2-, and 5-year survival was 71%, 53%, and 24%, respectively. Independent predictors of mortality were similar in both cohorts: age >65 years, white race, dialysis duration, peritoneal dialysis, and congestive heart failure, but not diabetes mellitus. Survival was significantly higher for coronary artery bypass grafting patients who received internal mammary grafts (hazard ratio, 0.83; P<0.0001). The probability of repeat revascularization accounting for the competing risk of death was 18% with bare metal stents, 19% with DES, and 6% with coronary artery bypass grafting at 1 year. Among dialysis patients undergoing coronary revascularization, in-hospital mortality was higher after coronary artery bypass grafting, but long-term survival was superior with internal mammary grafts. In-hospital mortality was lower for DES patients, but the probability of repeat revascularization was higher and comparable to that in patients receiving a bare metal stent. Revascularization decisions for dialysis patients should be individualized.

Coronary-subclavian steal syndrome: percutaneous approach.

Coronary subclavian steal syndrome is a rare ischemic cause in patients after myocardial revascularization surgery. Subclavian artery stenosis or compression proximal to the internal mammary artery graft is the underlying cause. The authors present a clinical case of a patient with previous history of non-ST elevation myocardial infarction, triple coronary bypass, and effort angina since the surgery, with a positive ischemic test. Coronary angiography revealed a significant stenosis of the left subclavian artery, proximal to the internal mammary graft.

A Case of Left Main Coronary Artery Disease in an Octogenarian Treated Surgically and Complicated by Myocardial Infarction: Decisions, Techniques, Rescue and Final Outcome

We report on an octogenarian patient presenting with an acute coronary syndrome due to significant left main coronary artery disease and severe ostial stenosis of the left anterior descending artery disease. Emergent bypass graft performed with “beating heart” consisted of left internal mammary graft to the mid left anterior descending artery with an “over-stent” anastomosis. The immediate post-operative phase was simple, however the patient presented on post-operative day 8 with extensive anterior myocardial infarction and cardiogenic shock. Emergent coronary angiogram showed subocclusive anastomotic stenosis. Percutaneous coronary intervention was performed on left main, proximal left anterior descending, and proximal circumflex arteries. Subsequently, the patient restored a satisfactory hemodynamic condition. A focus on the importance of decision for management of left main disease especially in octogenarian is presented, along with a review of the pertinent literature.

Anomalous Origin of the Left Internal Mammary Artery From the Aortic Arch

A 67-year-old diabetic man with a pacemaker for symptomatic bradycardia underwent cardiac catheterization for unstable angina, 19 years after coronary artery bypass graft surgery. There were bilateral pedicled internal mammary grafts—from the left internal mammary artery (LIMA) to the left

Late myocardial ischemia induced by a large fistula between left internal mammary graft and left pulmonary vein system.

A coronary fistula is an extremely rare coronary artery anomaly and its incidence is 0.08–0.4% (1). A fistula between the Left internal mammary graft (LIMA) graft and pulmonary vein after a coronary artery bypass graft (CABG) is a very rare event, which can result in recurrence of anginal symptoms related to coronary steal (2). We present a 57 year old male patient who had coronary bypass surgery 3 years earlier with a fistula between the LIMA graft and left pulmonary vein after CABG surgery. His ECG on admission revealed sinus rhythm with 1 mm ST depression in precordial leads V4 to V6. The patient was complaining of anginal symptoms with minimal exertion under medical care. Myocardial scintigraphy revealed large anteroseptal ischemia. The patient underwent coronary angiography and this revealed a critical stenosis in the middle of the aorto-right coronary bypass graft composed of a severe thrombotic component and critical stenosis of the proximal left anterior descending artery (LAD) with a patent distal runoff. LIMA graft angiography showed a large fistula draining to the left pulmonary vein system and then left atrium, which was causing cutting off of the distal blood supply of the LIMA graft to the LAD (Figure 1 and Video 1). The management of each individual patient who has LIMA graft fistula should depend on the anatomy of the fistula, clinical picture and the presence or absence of associated cardiac conditions. In our case, we decided to use warfarin and clopidogrel therapy for 2 months to decrease the amount of thrombus in the aorto-coronary saphenous graft then percutaneous stenting for the aorto-right coronary graft and the proximal LAD. Figure 1. Large fistula draining from left internal mammary graft to left pulmonary vein system and then left atrium

Angiogenesis between coronary grafts through the aortic wall

Following a total coronary occlusion, residual perfusion to the myocardium persists through native coronary collateral channels. Provided that they are of adequate size, collateral circulation may protect against myocardial infarction and death [1]. However, there is tremendous individual variability in the function of those neovascularizations among patients with chronic stenosis. Thus, the detailed mechanism of collateral artery growth is still unknown in the human adult. This report describes a case of a 61-year-old man that was admitted with progressive angina (CCS III on admission) for the last 3 months. He had a previous history of hypertension, dyslipidemia and insulindependent diabetes and two surgical myocardial revascularizations performed 14 and 8 years prior to admission. Medications taken on a daily basis included atenolol, amlodipine, trimetazidine, propatylnitrate, atorvastatin, metformin and insulin. Tc-Sestamibi Scintigraphy demonstrated irreversible defect of basal-inferior wall and moderate reversible defect of anterior-apical wall, along with reduced ventricular function during exercise. Coronary angiography showed occlusion of native vessels, pervious left internal mammary graft to a marginal branch and collateral circulation (CC) grade III to right coronary artery. Moreover, there was an ostial occlusion of a free right internal thoracic artery graft (RITA) to left anterior descending artery, which had a delayed filling through CC from a saphenous vein graft (SVG) to a

Coronary Artery Disease in Adult Congenital Heart Disease: Outcome After Coronary Artery Bypass Grafting

Atherosclerotic coronary artery disease may be seen during repair of adult congenital heart disease (ACHD). There are few data outlining outcomes of concomitant coronary artery bypass grafting (CABG) in these patients. Between February 1972 and August 2009, 122 patients (77 men) underwent concomitant CABG at the time of ACHD repair; median age was 64 years (range 40 to 85 years). Thirty patients (25%) had preoperative angina, 7 patients (6%) had previous myocardial infarction (MI), and 6 patients (5%) had previous percutaneous intervention. Most common primary cardiac diagnoses included secundum atrial septal defect (ASD) in 73 patients (60%), Ebstein's anomaly in 14 patients (11%), and partial anomalous pulmonary venous connection in 8 patients (7%). Operations included ASD repair in 78 patients (64%), tricuspid/pulmonary valve procedures in 23 patients (19%), and ventricular septal defect repair in 10 patients (8%). One bypass graft procedure was performed in 69 patients (57%), 2 bypass graft procedures were performed in 32 patients (26%), 3 bypass graft procedures were performed in 14 patients (11%), 4 bypass graft procedures were performed in 5 patients (4%), and 5 bypass graft procedures were performed in 2 patients (2%). There were 4 early deaths (3.3%). During a median follow-up of 6 years (maximum follow-up, 32 years), actuarial survival was 76% at 5 years and 56% at 10 years. In patients with left anterior descending (LAD) artery disease, survival was higher when a left internal mammary graft (LIMA) was used (5 years, 86% versus 66%; 10 years, 66% versus 36%; p<0.05). Concomitant CABG may be required at the time of correction of ACHD. Survival is higher when a LIMA graft is used, and late functional outcome is good, with a low incidence of late angina and need for reintervention.

Multidetector computed tomography of a giant left mainstem aneurysm

A 68-year-old gentleman with prior uncomplicated coronary bypass grafting (CABG) presented with worsening symptoms of angina and was accordingly referred for urgent coronary computed tomography angiography (CTA). Coronary CTA showed a dilated left mainstem (LMS) artery measuring 9 mm at the ostium that filled a large aneurysm (51 mm × 52 mm × 49 mm) ( Figure 1A ). The wall of the aneurysm was partly calcified and contained thrombus ( Figure 1B ). The contrast-filled lumen measured 25 mm, with the neck of the aneurysm measuring <4 mm in diameter. The left anterior descending (LAD) artery was attached to the anterosuperior aspect of the aneurysm and was obstructed at its origin while the left internal mammary graft …

Utility of Noninvasive Imaging in Suspected Saphenous Vein Graft Aneurysm Thrombosis

A 70-year-old man presented with 2 weeks of progressive typical angina without myocardial infarction. He had undergone coronary artery bypass grafting (CABG) in December 2006, using a left internal mammary graft to the left anterior descending artery, saphenous vein grafts (SVG) to the distal right coronary artery, and the second obtuse marginal branch of the left circumflex coronary artery. Coronary angiography showed a patent left internal mammary and SVG to the right coronary. The SVG to the circumflex filled slowly and was occluded midgraft without apparent distal perfusion of the circumflex system. Instead, on late angiographic images, contrast diffusion into an indistinct aneurysmal structure was noted (online-only Data Supplement Video 1). The native circulation had a calcified 95% distal left main stenosis and no …

Hybrid treatment of an aortic arch aneurysm in a patient with a patent right and left internal mammary graft

The aim of this report is to describe a known hybrid surgical and endovascular technique for aortic arch aneurysm repair in a special setting of a patient with previous coronary mammary bypass. We present a case of aortic arch aneurysm in a 66-year-old man with previous coronary bypass. He underwent a hybrid endovascular and surgical repair. All supraaortic vessels were debranched, keeping a continuous antegrade blood flow through the left and right internal mammary arteries to avoid myocardial ischemia. Endovascular treatment of aortic arch aneurysms is associated with less mortality and morbidity as compared with open surgery. The hybrid procedure with surgical debranching of the supraaortic vessels is the most commonly used method. In cases of previous coronary bypass with mammary arteries, care must be taken to maintain constant flow through the grafts during debranching.

OCT Characteristics of Saphenous Vein Graft Atherosclerosis

CORONARY ARTERY BYPASS GRAFTING (CABG) REMAINS A FIRST-LINE TREATMENT FOR CORONARY ARTERY DISEASE, with good long-term clinical outcomes. Although left internal mammary grafts have high long-term patency rates, in current CABG practice the overwhelming majority of patients also require saphenous

Transcatheter aortic valve implantation by left subclavian access in the presence of a patent LIMA to LAD graft

We present a case of successful implantation of the Corevalve aortic bioprosthesis via the left subclavian artery in a patient with a patent internal mammary graft to the left anterior descending artery. This unusual choice of access, in the presence of adequate caliber femoral arteries, was justified by the presence of mobile thrombi in the abdominal aorta. The risk of thrombus dislodgement and subsequent major cholesterol embolization was deemed higher than the risk of coronary ischemia due to the large caliber sheath required for transcatheter aortic valve implantation. This case shows that presence of a LIMA to LAD graft is not an absolute contraindication for homolateral subclavian access and that the procedure is feasible and relatively safe provided that certain rules are followed.

Chylothorax – a Rare Complication after Cardiac Surgery (a Case Report)

Chylothorax is a rare but severe complication of cardiac surgery. The authors present the case of a 76-year-old woman suffering from ischemic heart disease, after coronary artery bypass grafting that included a left internal mammary artery pedicle graft. On the ninth postoperative day the left-sided fluidothorax developed. The results of biochemical analysis were consistent with the chyle. Combined treatment with pleural drainage and total parenteral nutrition was effective.

Arteriovenous Fistula from the Left and Right Coronary Arteries -to- Pulmonary Artery Presenting with Acute Myocardial Infraction

This is a review of a case study of a bilateral coronary artery fistulae originating from the left anterior descending artery, plus the right coronary artery to form a spiral shape arteriovenous malformation, and draining into the pulmonary artery. The patient presented with an acute coronary syndrome and a myocardial infarction due to a complete occlusion of the left anterior descending, distal to the origin of the fistula branches arising from the proximal left anterior descending. The left anterior descending was grafted with left internal mammary graft with surgical resection of the fistula; the post operative course was uneventful. After 2 years, the patient continues to be asymptomatic and was back to heavy work with no complaints.

Prevalence and variability of internal mammary graft use in contemporary multivessel coronary artery bypass graft

To assess the current status of the prevalence and variability of internal mammary graft use in contemporary multivessel coronary artery bypass graft (CABG). The internal mammary artery (IMA) is considered the gold-standard conduit in coronary artery bypass graft (CABG) surgery. There is universal agreement that the IMA graft is associated with significantly improved short-term and long-term survival in CABG and the use of the IMA is recognized as a key performance measure world wide. In the recently developed Society of Thoracic Surgeons (STS) composite measure for CABG, use of an IMA was found to be the only intra-operative performance measure associated with quality of care. Furthermore, several studies have shown that bilateral IMA (BIMA) use improves long-term outcome compared with single IMA use. An objective assessment of surgical quality is essential to improve surgical outcomes. There is strong evidence that IMA graft use is associated with significantly improved short-term and long-term survival in CABG. In spite of this, the prevalence of IMA grafting is less than expected. Moreover, there is a large variability in IMA use by hospital. There are also disparities in IMA use by sex and race, which should be addressed in the interest of expanding the benefits of IMA grafting to the maximum possible number of patients. Although the frequency of IMA use in CABG procedures seems to increase each year, further actions are necessary at the individual clinician, institutional, and political levels to improve quality of care.

Invited Commentary

Invited Commentary

64-Slice Computed Tomography of Bovine Internal Mammary Artery Coronary Grafts

In cases where conventional aortocoronary grafts cannot be used, No-React bovine internal mammary artery is a possible alternative. The aim of this study was to assess the patency and clinical performance of bovine internal mammary artery as a coronary bypass conduit, using 64-slice computed tomography coronary angiography. Eleven patients (mean age, 68.2 + or - 5.9 years) received 11 bovine grafts between 2002 and 2006. Eight of these patients were alive after a mean follow-up of 29.4 + or - 16.3 months. Their mean additive EuroSCORE was 6.5 + or - 3.2. The mean number of distal anastomoses was 2.5 + or - 0.5. Six grafts were anastomosed to the right coronary artery, 2 to the left anterior descending artery, and 3 to the circumflex artery. All 11 bovine grafts were found to be occluded after 14.1 + or - 3.6 months. This demonstrates very poor results with the bovine coronary graft, thus we do not recommend its use, and we suggest considering an hybrid approach in selected cases.