Effects of Obesity on Outcomes in Endoscopically Assisted Coronary Artery Bypass Operations

  • Thomas A. Vassiliades
  • James L. Nielsen
  • James L. Lonquist

Abstract

Background: Obesity has been shown to be an independent risk factor for adverse outcomes and prolonged hospitalization following conventional coronary artery bypass (CAB). For this reason and because of increased technical challenges, obesity has been considered a relative contraindication for minimally invasive bypass. The purpose of this study was to determine if in fact severe or morbid obesity is an independent risk factor for patients undergoing minimally invasive CAB.

Methods: Outcome data of 350 consecutive endoscopic, atraumatic CAB procedures performed at our institution over a 4-year period were reviewed with respect to patient body mass index (BMI). All operations consisted of thoracoscopic left or right internal mammary artery (IMA) harvesting followed by off-pump grafting of the left anterior descending (with/without diagonal coronary artery) or right coronary artery via a 4-cm thoracotomy. Patients were divided into 4 groups: small (BMI £ 24 kg/m2), normal to mild obesity (24 kg/m2 < BMI 34 kg/m2), severe obesity (34 kg/m2 < BMI £ 40 kg/m2), and morbid obesity (BMI >40 kg/m2). Results: Although the BMI >34 kg/m2 groups had a higher incidence of hypertension, diabetes, and hypercholesterolemia, there was no statistical difference in operative risk between groups. Thirty-day mortality, conversion to sternotomy, transfusion rate, and wound, pulmonary, neurological, and myocardial complications were not significantly different between groups. The BMI >34 kg/m2 patients required longer IMA harvest times and total operating times, but the intensive care unit length of stay was not significantly different between groups. Hospital length of stay was longer for the BMI £ 24 kg/m2 group than for the BMI 18 to 34 kg/m2 group (P = .025). Conclusion: Despite increased technical difficulty caused by obesity, it is not an independent risk factor for patients undergoing minimally invasive CAB.

References

[WHO] World Health Organization. 1998. Obesity: preventing and managing the global epidemic: report of a WHO Consultation on Obesity, Geneva; June 3-5, 1997. Geneva, Switzerland: WHO.\nYamagishi T, Ishikawa S, Ohtaki A, Takahashi T, Ohki S, Morishita Y. 2000. Obesity and postoperative oxygenation after coronary artery bypass grafting. Jpn J Thorac Cardiovasc Surg 48:632-6.\nBader DS, Maguire T, Spahn C, O'Malley C, Balady G. 2001. Clinical profile and outcomes of obese patients in cardiac rehabilitation stratified according to National Heart, Lung, and Blood Institute criteria. J Cardiopulm Rehabil 21:210-7.\nBirkmeyer N, Charlesworth D, Hernandez F, et al. 1998. Obesity and risk of adverse outcomes associated with coronary artery bypass surgery. Northern New England Cardiovascular Disease Study Group. Circulation 97:1689-94.\nBrandt M, Harder K, Walluscheck K, et al. 2001. Severe obesity does not adversely affect perioperative mortality and morbidity in coronary artery bypass surgery. Eur J Cardiothorac Surg 19:662-6.\nCriqui MH, Klauber MR, Barrett-Connor E, Holdbrook MJ, Suarez L, Wingard DL. 1982. Adjustment for obesity in studies of cardiovascular disease. Am J Epidemiol 116:685-91.\nEngelman D, Adams D, Byrne J, et al. 1999. Impact of body mass index and albumin on morbidity and mortality after cardiac surgery. J Thorac Cardiovasc Surg 118:866-73.\nGurm H, Whitlow P, Kip K. 2002. The impact of body mass index on short- and long-term outcomes in patients undergoing coronary revascularization. Insights from the bypass angioplasty revascularization investigation (BARI). J Am Coll Cardiol 39:834-40.\nRanucci M, Cazzaniga A, Soro G, Morricone L, Enrini R, Caviezel F 1999. Obesity and coronary artery surgery. J Cardiothorac Vasc Anesth 13:280-4.\nSchwann T, Habib R, Zacharias A, et al. 2001. Effects of body size on operative, intermediate, and long-term outcomes after coronary artery bypass operation. Ann Thorac Surg 71:521-31.\nVassiliades T. 2001. Atraumatic coronary artery bypass (ACAB): technique and outcome. Heart Surg Forum 4:331-4.\n
Published
2005-02-02
Section
Articles