Use Of Internal Mammary Artery Research Articles

Internal Mammary Artery Use in Coronary Artery Bypass Grafting: Room for Improvement

Use of an internal mammary artery (IMA) during coronary artery bypass grafting is a nationally endorsed quality indicator. Nonetheless, the frequency

Should Saphenous Vein Grafts be the Conduits of Last Resort for Coronary Artery Bypass Surgery?

There is overwhelming evidence that internal mammary artery grafts improve survival and clinical outcomes after coronary artery bypass graft surgery. It has therefore become standard practice to use the left internal mammary artery as the graft of first choice. Given the overwhelming evidence for the superiority of internal mammary artery grafts, the question that naturally follows is whether the conduit of second choice should be the contralateral internal mammary artery, rather than a saphenous venous graft. This article reviews the evidence supporting the superiority of internal mammary artery grafts over other available conduits and addresses the selection of the second conduit after the left internal mammary artery. The current body of evidence, encompassing multiple clinical studies and employing different methodologies consistently, demonstrates that bilateral internal mammary artery grafting improves survival and long-term clinical outcome. The increasing longevity of postcoronary bypass patients with modern advances in medical and electrical therapies would augment the benefit of this procedure and argue for its greater utilization. Higher patency of arterial grafts may translate to a decreased need for repeat target vessel revascularization and may increase the cost-effectiveness of bilateral internal mammary artery use. However, in 2003, only 3% to 4% of patients undergoing surgical coronary revascularization received bilateral internal mammary artery grafts. There appears to be a potential to increase utilization of this procedure above the current rate. Increased utilization of this procedure would need a concerted effort by the cardiology and cardiac surgery community.

Prevalence and Variability of Internal Mammary Artery Graft Use in Contemporary Multivessel Coronary Artery Bypass Graft Surgery

Use of an internal mammary artery (IMA) is a well-recognized, nationally endorsed quality indicator for evaluating the process of operative care for coronary artery bypass graft surgery. An objective assessment of the current status of IMA use has not been systematically performed. This cross-sectional observational study analyzed data on 541 368 coronary artery bypass graft surgery procedures reported by 745 hospitals in the Society of Thoracic Surgeons National Cardiac Database from 2002 through 2005. We assessed the current status of IMA use, the association of hospital volume and IMA use, and disparities in IMA use by patient gender and race and by region of hospital location. Rates of using at least 1 IMA and bilateral IMA were 92.4% and 4.0%, with increasing trends over the years. Hospital volume was not significantly associated with IMA use. IMAs were used less frequently in women than men (for at least 1 IMA: odds ratio, 0.62; 95% confidence interval, 0.61 to 0.63; for bilateral IMA: odds ratio, 0.65; 95% confidence interval, 0.63 to 0.68) and less frequently in nonwhite patients than white patients (for at least 1 IMA: odds ratio, 0.84; 95% confidence interval, 0.81 to 0.87; for bilateral IMA: odds ratio, 0.79; 95% confidence interval, 0.75 to 0.83). There were significant differences in frequency of IMA use by hospital region. Frequency of IMA use in coronary artery bypass graft surgery is increasing; however, many patients still do not receive the benefits of IMA grafts, and some hospitals have a very low IMA use rate. Hospital volume is not associated with IMA use in coronary artery bypass graft surgery. Analysis of this critical performance measure reveals significant gender and race disparities.

Impact of Gender on Outcome after Coronary Artery Bypass Surgery

Following recent studies concerning the increased risk of coronary artery bypass surgery for women, the impact of sex is still a controversial issue. Between 1996 and 2006, 9,527 men and 3,079 women underwent isolated coronary artery bypass in our institute. To adjust for dissimilarities in preoperative risk profiles, propensity score-based matching was applied. Before adjustment, clinical outcomes in terms of operative mortality, arrhythmias, intensive care unit stay, and maximum creatine kinase-MB levels were significantly different for men and women. After balancing the preoperative characteristics, including height, no significant differences in clinical outcomes were observed. However, there was decreased use of internal mammary artery, less total arterial revascularization, and increasing creatine kinase-MB levels with decreasing height. This study supports the theory that female sex per se does not increase operative risk, but shorter height, which is more common in women, affects the outcome, probably due to technical difficulties in shorter patients with smaller internal mammary arteries and coronary vessels. Thus women may especially benefit from sequential arterial grafting.

Cirugía de revascularización miocárdica de la arteria descendente anterior con arteria mamaria interna izquierda sin circulación extracorpórea: Experiencia en el largo plazo

In recent years the use of left internal mammary artery (LIMA) as a gran to anterior descending artery (DA) with the off pump technique has been associated with similar good long term results as with the on pump technique.To report the results of LIMA to DA bypass grafting without extracorporeal circulation (EC) for isolated DA lesions.Descriptive study of 80 patients subjected to coronary surgery between 1999 and 2007.Mean age of patients was 63 + 10 years and 60 were male. There was no operative mortality or stroke. One patient with a myocardial infarction required a reoperation. Actuarial survival was 98% at 97 months.In this group of patients the use of LIMA as a coronary bypass gran to DA with the off pump technique is a safe surgical procedure, providing a prolonged cardiac event free survival (mortality, angina, myocardial infarction, and need for a new coronary procedure).

Beating heart anterior descending coronary artery grafting with left internal mammary artery: a long term follow up experience

In recent years the use of left internal mammary artery (LIMA) as a gran to anterior descending artery (DA) with the off pump technique has been associated with similar good long term results as with the on pump technique. To report the results of LIMA to DA bypass grafting without extracorporeal circulation (EC) for isolated DA lesions. Descriptive study of 80 patients subjected to coronary surgery between 1999 and 2007. Mean age of patients was 63 + 10 years and 60 were male. There was no operative mortality or stroke. One patient with a myocardial infarction required a reoperation. Actuarial survival was 98% at 97 months. In this group of patients the use of LIMA as a coronary bypass gran to DA with the off pump technique is a safe surgical procedure, providing a prolonged cardiac event free survival (mortality, angina, myocardial infarction, and need for a new coronary procedure).

Acute Presentation in Adult in Bland‐White‐Garland Syndrome: Double‐Conduit, Two‐Coronary Repair

Adult presentation with myocardial infarction in anomalous origin of the left main coronary artery from the pulmonary artery is rare. We describe the different coronary flow physiology in the adult form. A double-conduit repair with a separate feeder vessel to each limb of the left coronary circulation may be necessary to balance the myocardial demand and supply in large systemic collateral coronary beds. The report describes the use of the left internal mammary and radial artery for repair.

Sternectomy and Sternum Reconstruction for Infection After Cardiac Surgery

Sternum infection after cardiac surgery represents a severe complication with a high mortality rate. Therapeutic possibilities consist in "open packing" with specific antibiotic irrigation or in "en-block" resection. We report a case of sternum reconstruction using a titanium patch covered with bone-powder.

Factors affecting postoperative morbidity and mortality in isolated coronary artery bypass graft surgery

This study was conducted to investigate predictors of mortality before and after isolated coronary artery bypass grafting (CABG). Single-institutional data on risk factors and mortality were collected for 8890 patients who underwent isolated CABG by the same group of surgeons. The relationship between risk factors and outcome was assessed using univariate and multivariate analyses in two risk models: a preoperative model (model 1) and then a pre-, intra-, and postoperative model (model 2). The mean age of the patients (25.4% women and 74.6% men) was 58.5 +/- 9.7 years. Fifty-five (0.6%) patients died after surgery. Hypercholesterolemia was the most common comorbidity factor (61.1%), followed by hypertension, a smoking habit, recent myocardial infarction (MI) <21 days, and diabetes. Postoperative tamponade, graft occlusion, and MI (0.01%) were the least common complications. The patients spent 39.7 +/- 33.9 h in the intensive care unit (ICU) postoperatively. Patients were followed up for a minimum of 30 days. The multivariate analysis of our preoperative risk model revealed that the best predictors of operative mortality were a history of diabetes, hypertension, previous CABG, the presence of angina, arrhythmia, Canadian Cardiovascular Society Classification (CCS) of grade III or IV, ejection fraction (EF) < or =30%, three-vessel disease, and left main disease. After surgery, and with the inclusion of all the pre-, intra-, and postoperative variables into model two, the following were revealed to be prognostic factors for in-hospital mortality: a history of diabetes, hypertension, the presence of angina, CCS grades III or IV, EF -30%, absence of internal mammary artery (IMA) use, prolonged cardiopulmonary bypass (CPB) time, and prolonged ICU stay.

Total Arterial Myocardial Revascularization

Failure of saphenous vein graft conduits is the most common indication for coronary artery reintervention after coronary artery bypass surgery. To estimate the feasibility and efficacy of total arterial myocardial revascularization in our patients, routine use of pedicled bilateral internal mammary arteries with or without a radial artery was applied in our department for the past 7 years in 1825 consecutive patients. Total arterial revascularization was achieved in 1817 of 1825 consecutive patients (99.5%), with 5815 coronary anastomoses using only bilateral mammary arteries with or without a radial artery. Combined procedures were performed in 345 (18.9%) of the cases. Preoperative mean additive Euroscore was 7.4, and the early mortality rate was 2.6%. Regular use of both mammaries and radial artery in patients requiring myocardial revascularization is a feasible and efficient technique, and it is highly recommended as a gold standard.

Endovascular Treatment of Acute Type B Dissection and Kommerell’s Diverticulum

A 59-year-old man presented with severe hypertension and resistant interscapular pain. Transesophageal echocardiography and computed tomographic angiogram demonstrated acute type B dissection associated with aberrant right subclavian artery with 3.5 cm Kommerell's diverticulum. Open repair was deemed to be high risk to elevate perioperative mortality and morbidity of this surgical technique. Therefore the patient was managed with an endovascular procedure after 14 days of medical therapy because of resistant thoracic pain. We did not observe intraoperative or perioperative mortality and right arm ischemia or symptomatic subclavian steal.

Clinical and Angiographic Correlates of Short- and Long-Term Mortality in Patients Undergoing Coronary Artery Bypass Grafting

Differences in the clinical and angiographic factors associated with short- and long-term outcomes in patients undergoing coronary artery bypass grafting (CABG) are less known. Accordingly, differences were examined in clinical and angiographic correlates of short- and long-term mortality after CABG in 8,229 patients undergoing initial CABG enrolled in the Duke Cardiovascular Disease Database (1995 to 2002). Logistic regression and Cox proportional hazard modeling were performed to determine independent correlates of 30-day and long-term mortality. Death occurred in 2.4% at 30 days and 17.6% beyond 30 days at a median follow-up of 6 years in patients who underwent CABG. Multivariable models identified older age, lower left ventricular ejection fraction, lower or higher body mass index, cerebrovascular disease, lack of internal mammary artery use, and lower cholesterol to be associated with increased risk of both events. Although hemodynamic status (preoperative myocardial infarction, New York Heart Association class, and cardiogenic shock), female gender, and minority race were associated with 30-day death; co-morbid conditions (serum creatinine, chronic lung disease, diabetes, previous heart failure, peripheral vascular disease, and left main disease) were associated with increased long-term (beyond 30 days) death (c indexes 0.76 and 0.79 for the short- and long-term mortality models, respectively). In conclusion, our study suggested that correlates of acute and long-term death were different in patients undergoing CABG. These differences should be kept in context when counseling patients undergoing CABG and may help facilitate targeted strategies to improve short- and long-term mortality risks after CABG.

Revascularização do miocárdio com emprego de ambas artérias mamárias internas em pacientes com diabetes mellitus

We sought to describe the use of both internal mammary arteries (IMA) in patients with diabetes mellitus (DM) submitted to coronary artery bypass grafting (CABG). Between January of 1995 to August of 2005, 4.569 patients received isolated CABG in our institution, of these, 1.298 had DM. Mean sample age was 62 years, and total mortality was 2.18% (100 patients). We have used both IMA's in 700 patients, that here are split in two groups, with DM (group I, 148 patients), and without DM (group II, 552 patients). Patient selection for double IMA grafting was based on coronary artery anatomy and sternal bone quality, the later was evaluated during sternal transsection. When these two factors were considered favorable, we harvested both IMA's, not mattering if the patient had or had not DM. During IMA's harvest, care was taken not to open the pleural spaces. There was small difference between the two groups in terms of morbidity and mortality. Our data suggest that patients with DM can benefit of double IMA's grafting, with little increase in risk for complications if its application is carefully indicated.

Long drug-eluting stent implantation for a diffusely diseased right internal mammary artery

The frequent use of the internal mammary artery as a bypass graft has brought about an increasing need for angioplasty to treat stenotic arterial grafts. Percutaneous interventions of internal mammary artery grafts by balloon angioplasty or stenting with bare-metal stents have been described in the past. However, implantation of bare-metal stents was associated with high rates of restenosis. The introduction of drug-eluting stents for the treatment of diseased native coronary vessels has been associated with a reduced need for repeat intervention compared with bare-metal stents for both low-risk lesions and high-risk, complex lesions, including the 'long lesion' subset. We describe a case of long drug-eluting stent implantation for a diffusely diseased right internal mammary artery.

Predictors of Early Postoperative Atrial Fibrillation after Off-Pump Myocardial Revascularization

: We determined the incidence and the predisposing factors of atrial fibrillation (AF) after aorta nontouch coronary artery bypass grafting without extracorporeal circulation. : From February 2001 to November 2005, 1359 patients (1159 men, 85.3%) of mean (±SD) age 64.8 (±9.8) years, who underwent off-pump coronary artery bypass grafting (OP-CAB), were prospectively enrolled. Demographics, perioperative data, and comorbidities were recorded in all patients. A 24-hour rhythm monitoring was performed in all patients until hospital discharge. : Among 1359 patients, 273 (20.1%) had development of atrial fibrillation in the early postoperative period. Patients with AF had higher mean (±SD) age, 68.3 (±8.8) years, compared with control subjects [63.9 (±9.9)] (P ≤ 0.0005). Univariate analysis showed that apart from age, history of arterial hypertension (P ≤ 0.02), chronic obstructive pulmonary disease (P ≤ 0.02), and the use of bilateral internal mammary arteries (P ≤ 0.01) were predisposing factors for the development of AF. Logistic regression analysis showed that age, history of arterial hypertension, and the use of bilateral internal mammary arteries were predisposing factors for early postoperative AF after OP-CAB. : Atrial fibrillation occurred in approximately 20% of patients undergoing OP-CAB, mainly in older patients with arterial hypertension who received bilateral internal mammary artery grafts.

Semi-skeletonized internal mammary grafts and phrenic nerve injury: Cause-and-effect analysis

Phrenic nerve injury after cardiac surgery increases postoperative pulmonary complications. The purpose of this study was to analyze the causes and effects of phrenic nerve injury after cardiac surgery. Prospectively collected data on 2084 consecutive patients who underwent cardiac surgery from Jan. 1995 to Feb. 2002 were analyzed. Twenty-eight preoperative and operation related variables were subjected to logistic analysis with the end point being phrenic nerve injury. Then phrenic nerve injury and 6 perioperative morbidities were included in the analysis as variables to determine their independent predictive value for perioperative pulmonary morbidity. An identical approach was used to identify the independent risk factors for perioperative mortality. There were 53 phrenic nerve injuries (2.5%). There was no phrenic nerve injury in non-coronary surgery or coronary surgery using conduits other than the internal mammary artery. The independent risk factors for phrenic nerve injury were the use of internal mammary artery (Odds ratio (OR) = 14.5) and thepresence of chronic obstructive pulmonary disease (OR = 2.9). Phrenic nerve injury was an independent risk factor (OR = 8.1) for perioperative pulmonary morbidities but not for perioperative mortality. Use of semi-skeletonized internal mammary artery harvesting technique and drawing attention to possible vascular or mechanical causes of phrenic nerve injury may reduce its occurrence. Unilateral phrenic nerve injury, although rarely life-threatening, is an independent risk factor for postoperative respiratory complications. When harvesting internal mammary arteries, it should be kept in mind avoiding stretching, compromising, or inadvertently dissecting phrenic nerve is as important as avoiding damage of internal mammary artery itself.

Composite arterial grafting

The success of coronary artery bypass grafting, the gold standard for the treatment of multivessel coronary artery disease, is limited by poor long-term vein-graft patency. By contrast, the left internal mammary artery has been demonstrated to have a superior graft patency rate and has provided excellent clinical results. This suggests that the use of arterial conduits for coronary artery bypass grafting may be beneficial for long-term results. Recently, there has been an upsurge in the use of arterial grafts for myocardial revascularization based on the clinical advantage of the use of the left internal mammary artery as a bypass conduit. Many retrospective studies have supported the safety and the effectiveness of arterial grafting, and it has become apparant that the free arterial graft can be used as a branched or a lengthened conduit to the in situ arterial graft by adopting one or more of the several composite grafting techniques. Arterial composite grafts with or without sequential grafting techniques appear an attractive strategy as increased number of distal coronary anastomoses can be performed, with a limited number of grafts, avoiding proximal aortic anastomoses. However, concerns regarding the total dependence of the coronary bypass flow on the flow of one in situ arterial graft and technical error, resulting in compromised flow in one or both limbs of the composite graft have prevented composite arterial grafting from being universally adopted. It is expected that in the near future a prospective, multi-institutional, randomized controlled trial, to compare the short- and long-term outcomes of exclusive arterial grafting using composite and conventional aortocoronary revascularization strategies, will be undertaken to validate the safety and efficacy of composite arterial grafting.

Late Results of Combined Carotid and Coronary Surgery Using Actual Versus Actuarial Methodology

Controversy exists over the short-term results and long-term efficacy of concomitant coronary artery bypass grafting and carotid endarterectomy. Additionally, in this population actual versus actuarial assessment of nonfatal late events has not been previously reported. Hospital records of 500 consecutive patients having concomitant carotid endarterectomy and coronary artery bypass grafting between 1979 and 2001 were reviewed, allowing at least 1 year of follow-up on all patients. Long-term nonfatal complications were assessed by actual and actuarial methods. Patient demographics revealed a mean age of 69 years; 74% (370 patients) were male; 75% (377 patients) presented with unstable coronary syndromes; 10% (50 patients) had an intraaortic balloon pump; and 66% (329 patients) were neurologically asymptomatic. Hospital mortality was 3.6% (18 patients). Significant multivariable predictors of hospital death were preoperative transient ischemic attack or myocardial infarction, and nonelective operation. Perioperative strokes were 4.6% (23 patients), of which 2.4% (12 patients) were ipsilateral and 2.2% (11 patients) were contralateral. Significant multivariable predictors of stroke were peripheral vascular disease and use of the right internal mammary artery. Ten-year actuarial survival was 43%. Ten-year actual versus Kaplan-Meier actuarial freedoms with 95% confidence limits from late events were myocardial infarction 87% (78% and 92%) versus 81% (75% and 87%); percutaneous coronary intervention 92% (85% and 96%) versus 89% (84% and 94%); reoperative coronary grafting 96% (89% and 99%) versus 94% (90% and 98%); total stroke 85% (77% and 91%) versus 82% (76% and 87%); ipsilateral stroke 90% (83% and 94%) versus 87% (82% and 92%); carotid endarterectomy 82% (73% and 88%) versus 75% (69% and 82%). Concomitant carotid and coronary artery surgery is safe and effective, particularly in preventing ipsilateral stroke, and neutralizes the impact of unilateral carotid stenosis on early and late stroke. Actual, not actuarial, methods more accurately represent the true risk of nonfatal late events.

Single Versus Bilateral Internal Mammary Artery for Isolated First Myocardial Revascularization in Multivessel Disease: Long-Term Clinical Results in Medically Treated Diabetic Patients

We evaluated our experience to investigate if the use of bilateral internal mammary artery (BIMA) grafting, with or without complementary saphenous vein grafts (SVG), increases the quality of the results of coronary bypass grafting in medically treated diabetic patients who undergo first myocardial revascularization, when compared with the use of a single left internal mammary artery (LIMA) and SVG. From October 1991 to December 2001, 558 diabetic patients with multivessel coronary disease had first isolated myocardial revascularization using LIMA and SVG (group LIMA) in 217 cases and BIMA +/- SVG (group BIMA) in 341. Propensity score analysis identified 400 patients, 200 for each group, with similar preoperative characteristics. Thirty-day outcome and 8-year freedom from death from any cause, cardiac death, acute myocardial infarction (AMI), AMI in a grafted area, redo/percutaneous transluminal coronary angioplasty (PTCA), redo/PTCA in a grafted area, target cardiac events, and any event were evaluated. Follow-up ranged from 2.0 to 12.2 years (mean 6.0 +/- 2.0). There was no difference between groups except the cardiac deaths, which were significantly higher in the LIMA group (7 versus 0, p = 0.015). The BIMA group showed better 8-year freedom from death any cause (86.7 +/- 3.2 versus 79.5 +/- 4.1, p = 0.0274), cardiac death (96.3 +/- 1.4 versus 88.4 +/- 4.0, p = 0.0406), acute myocardial infarction (99.5 +/- 0.5 versus 92.0 +/- 3.9, p = 0.0092), and acute myocardial infarction in a grafted area (99.5 +/- 0.5 versus 93.4 +/- 3.7, p = 0.0204). Cox analysis confirmed that the use of LIMA and SVG was an independent predictor for lower freedom from death (hazard ratio [HR] = 1.8, p = 0.0310), cardiac death (HR = 1.9, p = 0.0426), AMI (HR = 9.7, p = 0.0033) and AMI in a grafted area (HR = 8.2, p = 0.0410). In diabetic patients with multivessel disease who undergo first myocardial revascularization, BIMA +/- SVG provides higher freedom from death, any cause, and cardiac-related death, if compared with LIMA + SVG. It plays a protective role in reducing the incidence of late AMI.

Revascularización miocárdica de la arteria descendente anterior con arteria mamaria interna izquierda con circulación extracorpórea: seguimiento a 10 años

The use of left internal mammary artery (LIMA) as a graft to anterior descending artery (LAD) has been associated with better long term results in coronary surgery. To assess and report the long-term results of LIMA to LAD bypass grafting for isolated LDA lesions. Retrospective analysis of the medical records and surgical protocols of 40 patients (aged 60+/-10 years, 28 male) subjected to coronary surgery between 1992 and 2002. Thirty-four patients presented with unstable angina. On angiography, the LAD had a proximal obstruction in 35 patients. Sixteen presented with a myocardial infarction of the LAD territory. Six were managed previously with angioplasty; four had a new critical obstruction, 1 was catalogued as a procedure failure, and one was totally occluded. There was no operative mortality, myocardial infarction, stroke or need for re operation. There were two late deaths, caused by an advanced cardiac failure at 120 months in one patient, and chronic renal failure at 61 months of follow-up in another. Actuarial survival probability was 100%, 93% and 75% at 1, 5 and 10 years. Probability of freedom from angina was 98%, and freedom of suffering a new myocardial infarction was 100% at more than 10 years. The probability of no need for a new coronary procedure (angioplasty or surgery) also was 100% at more than 10 years. The use of LIMA as a coronary bypass graft to LAD is a safe surgical technique, with an excellent duration and permeability and also provides a prolonged time free from cardiac events as mortality, angina, myocardial infarction, and the need of a new coronary procedure.