Impact of mammary grafts on coronary bypass operative mortality and morbidity

doi:10.1016/0003-4975(94)90546-0

The Annals of Thoracic Surgery

Volume 57, Issue 3, March 1994, Pages 559-569

https://doi.org/10.1016/0003-4975(94)90546-0 Get rights and content

Abstract

The internal mammary artery is frequently used as a coronary artery bypass graft conduit because of superior long-term patency. The purpose of this study was to determine if there was also an advantage to the internal mammary artery in terms of operative mortality and morbidity. The Department of Veterans Affairs Cardiac Surgery Database was reviewed for two separate time periods, April 1987 through March 1989 and October 1990 through September 1991. During these periods, 14,172 patients underwent coronary artery bypass grafting. Univariate and multivariate logistic regression analyses were used to determine preopetative variables predictive of operative mortality and morbidity, with the independent variable of use of the internal mammary artery added to previously determined indicators. The total group was analyzed in risk quartiles according to expected mortality. Univariate analysis revealed an operative mortality of 6.8% in the early period and 6.5% in the latter period for the saphenous vein groups compared with 3.7% and 3.2%, respectively, for the internal mammary artery groups (p = 0.000). Multivariate analysis revealed an odds ratio of operative death with use of the internal mammary artery graft versus use of vein grafts of 0.78 during the first period and 0.72 during the second period, reductions of 22% and 28%, respectively. There were 29% and 37% reductions in the odds of operative mortality in the highest-risk quartile group of patients using the internal mammary artery graft. The odds ratio of developing mediastinitis with one internal mammary artery graft was 1.84 (p < 0.01) in the first time period and 1.11 in the second time period (p = not significant). However, with multiple mammary bypass grafts, the odds ratios were 3.70 (p < 0.01) and 2.96 (p < 0.01) in the respective time periods. On the basis of this study, it is concluded that internal mammary artery grafts in addition to providing superior long-term patency also decreased operative mortality after adjustment for patient risk factors. Use of the mammary artery does not consistently increase operative complications with the exception of mediastinitis when both internal mammary arteries are employed.

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Cited by (79)

Technique of Y and T grafts
2020, Technical Aspects of Modern Coronary Artery Bypass Surgery
Coronary artery bypass grafting is the treatment of choice for patients with three-vessel and left main coronary artery disease and the left internal thoracic artery (ITA) is the conduit of choice for coronary artery bypass grafting because of superior graft patency, reduced cardiac events, and enhanced short- and long-term results. It is estimated that approximately 95% of patients who undergo coronary artery bypass grafting in the United States and approximately 90% in Europe receive one ITA, usually the left, plus a saphenous vein graft.
The exclusive use of arterial conduits, namely, both ITAs or one ITA plus the radial artery (RA), is seen by a few as a potential solution for the late failure of saphenous vein grafts. It can be pursued using both pedicled ITAs or one ITA, usually the left, plus the RA as a composite Y/T-graft. This configuration as the double advantage to (1) extend as much as possible the number of distal anastomosis reducing at the same time the invasiveness in terms of conduit harvesting length and (2) avoid ascending aorta manipulation when combined with an off-pump procedure, significantly reducing the incidence of postoperative cerebrovascular accidents (CVAs) [anaortic-coronary artery bypass graft (CABG)]. The risk of CVAs after coronary artery bypass grafting still remains the major disadvantage for CABG when compared with percutaneous coronary intervention and its incidence increases as patient population ages.
Notwithstanding these relevant benefits the adoption of composite Y/T-graft along with an off-pump procedure is limited by a few concerns mainly attributable to:
- 1.
  the adequacy of the left ITA as single inflow for all the left ventricle;
- 2.
  the crucial importance and the technical complexity of the Y/T-graft anastomosis on the left ITA; and
- 3.
  the use of an off-pump technique plus sequential coronary artery anastomoses during anaortic-CABG.
Moreover, the whole procedure is perceived as much more technically demanding than standard coronary artery bypass grafting, hence to be performed only by a niche of specifically trained and expert surgeons.
This paper will discuss the reasons upon which these concerns are based along with the state-of-the-art technique to perform Y/T-graft anastomosis.
Bilateral internal thoracic artery grafting in India—Time to raise the bar
2017, Indian Heart Journal
Citation Excerpt :
The objective of coronary artery bypass graft (CABG) surgery is to ameliorate the symptoms of patients with coronary artery disease and of long– term survival benefit.1 The use of left internal thoracic artery (LITA) to bypass stenosed left anterior descending (LAD) coronary artery as a surgical strategy in patients undergoing coronary artery bypass grafting has demonstrated improved survival which may be due to the higher rates of long-term patency of LITA grafts.2–4 The evidence of improved survival from several observational studies is so convincing that over 95% of patients undergoing CABG in the Unites States and 90% of patients in United Kingdom receive at least one ITA graft.5,6
Bilateral internal thoracic artery (BITA) grafting strategy is the current trend in coronary artery bypass grafting for multivessel coronary artery disease. Although better long-term outcomes have been shown, BITA grafting is underutilized as a main strategy for revascularization by most of the surgeons. The survey was conducted to ascertain the current usage and concerns of BITA grafting in India.
Database of 856 Indian cardiac surgeons currently with predominantly adult practice was prepared and a questionnaire was sent about use of single and bilateral ITA grafts and BITA grafting strategy in different clinical scenarios.
A total of 112 surgeons (13.08%) from 75 institutions responded and 92 surgeons (10.7%) completed the survey. Single ITA is used by 79% of surgeons in more than 90% of their patients. 31% and 29% of surgeons use BITA grafting in 5–10% and 11–98% of their patients respectively. 53% of surgeons avoided the usage of BITA grafting in patients with smoking, 35% of surgeons in chronic obstructive pulmonary disease, 58% of surgeons in obesity and 62% of surgeons in acute coronary syndrome, 36% of surgeons in patients with left ventricular dysfunction and 61% of surgeons in patients with poor coronary anatomy. The concerns for BITA usage are risk of deep sternal wound infection (DSWI) (40%), increased operative time (27%), unknown superiority (12%) and limited length of right ITA (5%).
The usage of BITA grafting is restricted to 10% in India and main concerns are DSWI and increased operative time.
The Surgical Treatment of Coronary Artery Occlusive Disease: Modern Treatment Strategies for an Age Old Problem
2017, Surgical Clinics of North America
Mediastinitis
2014, Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases
Risk stratification and prognostic effects of internal thoracic artery grafting during acute myocardial infarction
2013, Journal of Thoracic and Cardiovascular Surgery
Citation Excerpt :
The positive benefits of ITA grafting on long-term survival, freedom from cardiac events, reoperation, and graft patency are well documented.19,20 Lower operative mortality also has been reported in the general population undergoing CABG.21-23 However, outcomes with ITA grafting in the early post-MI state have not been studied, and in the present analysis, ITA grafting in patients with MI in less than 24 hours was associated with a halving of operative mortality.
Surgeons are occasionally requested to perform coronary artery bypass grafting during acute myocardial infarction. We intended to test the safety of coronary artery bypass grafting and internal thoracic artery grafting early after myocardial infarction using the Society of Thoracic Surgeons database.
The database was queried for isolated coronary artery bypass grafting less than 24 hours after a myocardial infarction from 2002 to 2008. By using multivariable logistic regression and classification trees, risk models were created to stratify this group of patients. The independent prognostic effect of internal thoracic artery grafting was examined using standard risk-adjusted mortality comparisons.
A total of 44,141 patients were identified, with an overall operative mortality of 7.9%. Cardiogenic shock occurred in 21%, percutaneous coronary intervention within 6 hours before surgery was performed in 11%, myocardial infarction within 6 hours before surgery occurred in 37%, preoperative intra-aortic balloon pump was used in 50%, and internal thoracic artery grafting was performed in 79% of the patients. Myocardial infarction in less than 24 hours was associated with higher operative mortality (odds ratio, 3.25) and major morbidity (odds ratio, 2.54). Emergency/salvage status (odds ratio, 6.43), age more than 80 years (odds ratio, 4.07), dialysis (odds ratio, 3.08), and cardiogenic shock (odds ratio, 2.79) were independent mortality predictors. Patients with nonemergence salvage status, absence of cardiogenic shock, creatinine less than 1.5 mg/dL, and age less than 70 years represented 48% of the population and exhibited a lower mortality rate of 2%. Internal thoracic artery grafting was independently associated with a lower risk of mortality (odds ratio, 0.52; P < .0001) and did not seem to compromise outcomes.
Coronary artery bypass grafting less than 24 hours after myocardial infarction carries a higher operative risk but can be performed safely in selected patients. Although confounding variables may exist, internal thoracic artery grafting was associated with improved outcomes. Internal thoracic artery use in this setting is less than ideal, and taking time to harvest internal thoracic artery grafts in patients with acute myocardial infarction might be encouraged.
Does the use of bilateral internal mammary artery grafts impact survival of veterans undergoing coronary artery bypass surgery?
2008, American Journal of Surgery
The impact of bilateral internal mammary artery (BIMA) versus single left internal mammary artery (LIMA) grafts on long-term survival in veterans after coronary artery bypass graft (CABG) surgery is unknown.
A review of prospectively collected data identified all patients (n = 784) who underwent primary isolated CABG surgery from December 1991 through December 1998. Grafting was performed with LIMA in 713 (90.9%) patients and with BIMA in 71 (9.1%) patients. We identified 66 propensity-matched patient pairs.
The matched cohort was all male. The mean follow-up was 9.7 ± 3.8 years. Comparing matched patients showed no significant survival benefit for the BIMA group versus the LIMA group at 5 years (89% versus 86%) and 10 years (73% versus 69%) (P = .99). Factors associated with decreased survival were advanced age, higher New York Heart Association heart failure class, and diabetes.
Using BIMA grafting instead of LIMA grafting had no significant survival benefit for male veterans who underwent CABG surgery. Further study is needed to fully evaluate the role of BIMA grafting in this unique patient population.

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^☆: Presented at the Twenty-ninth Annual Meeting of The Society of Thoracic Surgeons, San Antonio, TX, Jan 25–27, 1993.

^☆☆: Supported by the Department of Veterans Affair Health Services Research and Development Service and the Office of Quality Management, Department of Veterans Affairs Central Office.

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Original articleImpact of mammary grafts on coronary bypass operative mortality and morbidity☆,☆☆

Abstract

J Thorac Cardiovasc Surg

Ann Thorac Surg

Ann Thorac Surg

Ann Thorac Surg

Ann Thorac Surg

J Thorac Cardiovasc Surg

Ann Thorac Surg

Ann Thorac Surg

Original article
Impact of mammary grafts on coronary bypass operative mortality and morbidity☆,☆☆