doi: 10.1161/01.CIR.0000120292.65143.F5
(Circulation. 2004;109:1206-1211.)
© 2004 American Heart Association, Inc.
Clinician Update |
Off-Pump Coronary Artery Bypass Surgery
Fundamentals for the Clinical Cardiologist
From the Division of Cardiac Surgery, Toronto General Hospital (S.V., P.W.M.F., R.D.W., P.E.S., M.V.B.), and the Division of Cardiac Surgery, St Michael’s Hospital (D.B., D.L., L.E., Y.L.), Toronto, Ontario, Canada.
Correspondence to Subodh Verma, MSc, MD, PhD, Division of Cardiac Surgery, Toronto General Hospital, 200 Elizabeth St, 14 EN-215, Toronto, Ontario, Canada M5G 2C4. E-mail subodh.verma{at}sympatico.ca
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Introduction |
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Case Report: Mrs. G is a 65-year-old retired banker who has had Canadian Cardiovascular Society class III angina for the past 2 months and symptomatic intermittent claudication for the past year. Her past medical history is unremarkable except for the presence of multiple vascular risk factors (smoking, hypertension, dyslipidemia, and diabetes). Coronary angiography revealed triple vessel disease involving the left anterior descending, second obtuse marginal, and right coronary arteries, as well as the akinetic anterior and inferior walls, with an estimated ejection fraction of 30%. Carotid duplex revealed 40% stenosis of the right internal carotid artery and 60% stenosis of the left internal carotid artery. A chest x-ray showed a possible calcified ascending aorta. The patient was referred for consideration of coronary artery bypass graft (CABG) surgery. Is Mrs. G a candidate for off-pump CABG? What are the indications, precautions, and considerations that facilitate decision-making about off-pump CABG surgery?
Conventional CABG surgery uses cardiopulmonary bypass (CPB) to allow cardiac surgeons to operate on a motionless heart that has been arrested by means of cardioplegia. CABG with CPB (on-pump CABG) quickly became the gold standard surgical procedure for myocardial revascularization, as it allowed surgeons to bypass multiple coronary arteries with greater control and precision. However, recently there has been increasing interest in the development and use of technologies that allow surgeons to perform CABG surgery without CPB (known as off-pump CABG or OPCAB).
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Rationale for the Development of OPCAB Surgery |
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TopIntroductionRationale for the Development...OPCAB TechnologyPatient SelectionRecent EvidenceWhat Does the Future...References |
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CPB is not a benign intervention. It is associated with a number of adverse consequences that are primarily related to a systemic inflammatory response elicited by the activation of cellular and humoral mediators as circulating blood comes into contact with the extracorporeal circuit of the CPB machine. The biochemical, cellular, and molecular aspects of this pump-induced inflammatory response are believed to contribute to postoperative myocardial, renal, and neurological dysfunction, coagulopathies, respiratory failure, and multiple organ dysfunction.1,2 On-pump CABG is also associated with microembolization of gaseous and particulate matter from blood constituents and lipids as they are cycled through the CPB circuit,3 a process implicated in the development of postoperative neurological and cognitive dysfunction.
The development and application of OPCAB technology has largely been driven by the hope of decreasing the incidence and/or severity of these adverse outcomes by performing CABG surgery without CPB. Impetus for this technology has been driven by reports indicating a reduction in early mortality,4–7 early neurocognitive dysfunction,8–11 stroke,7,12–14 and renal failure15–17 when compared with outcomes in patients undergoing conventional CABG with CPB.
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OPCAB Technology |
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TopIntroductionRationale for the Development...OPCAB TechnologyPatient SelectionRecent EvidenceWhat Does the Future...References |
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Successful OPCAB surgery depends on the optimization of cardiac positioning to access target coronary vessels, cardiac stabilization to dampen local cardiac wall motion around the distal anastomotic site, and techniques directed at minimizing myocardial injury from the interruption of coronary perfusion while adequately visualizing the distal anastomotic site.
Cardiac Positioning
Unlike on-pump CABG, hemodynamic compromise with OPCAB surgery is a concern during cardiac positioning. Lifting and rotating the heart during OPCAB may alter such hemodynamics as cardiac output, mean arterial pressure, stroke work, left ventricular end-diastolic pressure, and right atrial pressure. As expected, greater changes arise when the heart is positioned to expose the lateral wall compared with the anterior aspect of the heart.18–20 These hemodynamic effects are primarily related to the compression and geometrical distortion that occurs when the heart is displaced using either conventional deep pericardial retraction sutures or sutured stockinet.19 Fluid and inotropic use in addition to placing the patient in the Trendelenburg position may limit these effects18 and prevent intraoperative conversion to CPB.21
Heart positioning devices available for use during OPCAB are generally suction devices that pull the heart up either by apical or non-apical attachment (Figure 1 and Figure 2). Sepic et al19 reported that target vessel exposure using an apical suction device resulted in near-baseline hemodynamics when compared with exposure by means of deep pericardial retraction sutures.
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Cardiac Wall Motion Stabilization
Local cardiac wall immobilization at the site of the coronary arteriotomy is essential to allow for optimal anastomotic suturing. A number of devices have been developed whereby surgeons can immobilize small areas of the heart either by local compression to the epicardial surface of the heart or by vacuum suction to pull up on the epicardium surrounding the target arteriotomy site. Some devices, such as the Coro-Vasc System (CoroNeo Inc), use silastic snares that are looped around the target coronary vessel and then fixed to a small immobile plate, thus directly immobilizing the target vessel (Figure 1). As with cardiac positioning, cardiac wall immobilization devices used during OPCAB surgery can also compromise hemodynamic stability, an effect that has been observed with both compression-type and suction-type immobilizers.22
Preventing Intraoperative Myocardial Ischemia
Displacement of the beating heart, combined with local wall motion fixation during OPCAB surgery, may interfere with coronary blood flow and contribute to myocardial ischemia.23,24 Furthermore, temporary occlusion of the target coronary vessel during OPCAB surgery is typically required to allow adequate visualization for creation of the distal anastomosis. This causes regional myocardial ischemia and may contribute to hemodynamic instability.
Intraluminal shunts can be placed within the anastomotic vessel, allowing distal perfusion during bypass grafting (Figure 2). Several studies have reported that these shunts are safe, protecting the regional myocardium from ischemia and preventing left ventricular dysfunction.24–27 Because distal regional ischemia is generally localized, transient, and well tolerated, especially in cases of bypass to an occluded vessel, shunts are used only when necessary to minimize the risk of vessel damage via intraluminal coronary manipulation and subsequent graft failure.28
Other techniques, including passive and active distal coronary perfusion through the coronary artery being bypassed, have been developed and studied.29–33 Passive distal coronary perfusion involves shunting of blood typically from either the aorta or the femoral artery through to the distal coronary target, whereas active perfusion uses an in-line pump to augment flow to the distal coronary artery. Studies examining the physiological effect of active versus passive distal coronary perfusion have shown that active distal coronary perfusion provides superior myocardial protection compared with passive perfusion.31,32
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Patient Selection |
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TopIntroductionRationale for the Development...OPCAB TechnologyPatient SelectionRecent EvidenceWhat Does the Future...References |
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Before the development of technology that gave surgeons safe access to the lateral and posterior coronary arteries, OPCAB surgery was reserved for patients who needed single or double coronary artery bypasses of the anterior vessels, for patients who tended to be younger, and for those who had intact left ventricular function. As multiple coronary bypasses covering all coronary territories became possible with the development of cardiac positioning and stabilization devices, OPCAB surgery was directed toward those patients who were at high risk of complication from CPB and thus would derive the most benefit from OPCAB. Such patients tended to be elderly and to have comorbid conditions, such as carotid disease, renal dysfunction, chronic pulmonary disease, peripheral vascular disease, and atherosclerotic ascending aortic disease.34 As technology has advanced and surgeons have become comfortable performing OPCAB surgery, a more diverse patient population has undergone CABG off-pump. Retrospective studies show that this procedure is safe and well tolerated by most patients. In fact, surgeons who routinely use this technology believe that up to 90% of patients referred for CABG can safely undergo OPCAB surgery.35 Furthermore, higher risk patients, including those undergoing reoperative CABG, diabetics, and the elderly may gain the most benefit from OPCAB surgery.36 Hemodynamic instability or poor targets (ie, intramyocardial and/or diffusely diseased vessels) are considered to be absolute contraindications to OPCAB surgery. Other precautions and relative contraindications are listed in Table 1.
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Recent Evidence |
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TopIntroductionRationale for the Development...OPCAB TechnologyPatient SelectionRecent EvidenceWhat Does the Future...References |
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With the growing interest in OPCAB surgery over the last decade, a number of studies have reported the safety and efficacy of OPCAB. Indeed, randomized trials demonstrate that OPCAB surgery yields results at least comparable to on-pump surgery in the early and mid-term postoperative periods, and that OPCAB surgery has advantages in a number of areas37–44 (Table 2).
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What Does the Future Hold? |
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TopIntroductionRationale for the Development...OPCAB TechnologyPatient SelectionRecent EvidenceWhat Does the Future...References |
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The last decade has witnessed a tremendous interest in OPCAB technology with promising preliminary results in diverse populations. Questions surrounding the adequacy of long-term revascularization with OPCAB remain; however, over the next few years, the results of late follow-up will be reported to determine whether OPCAB is associated with long-term graft patency, one of the most important considerations of this technique. In the interim, OPCAB technology seems to be safe and to offer equal, if not better, short-term results. As cardiac surgeons become more comfortable with the technique, it is expected that by the year 2005, up to 50% of CABG surgery will be performed off-pump.45 OPCAB surgery remains technically more demanding and has a steeper and longer learning curve. As OPCAB becomes more frequent, cardiac surgical trainees will have the opportunity to routinely incorporate it into their residency training. Devices such as the sutureless coronary anastomotic connectors have the potential of transforming this technically challenging procedure into one that is more easily performed.46
Mrs. G underwent OPCAB surgery with a left internal thoracic artery to the left anterior descending artery and left radial T graft (off the left internal thoracic artery) to the second obtuse marginal and distal posterior descending artery (Figure 3). Her perioperative course was unremarkable, and she was discharged from hospital at day 4 after surgery. By using the OPCAB technology and radial T grafting, complete revascularization was accomplished without manipulation or cannulation of the atherosclerotic aorta.
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Note Added in Proof
During the review process, several clinical trials comparing OPCAB to on-pump CABG were published. In a randomized study, Khan et al47 showed that OPCAB caused less myocardial damage and was as safe as on-pump coronary surgery, but it resulted in lower graft-patency rates after 3 months, which may influence long-term outcomes. In a randomized single-center trial conducted on 300 patients requiring CABG surgery, Legare et al48 were unable to demonstrate any advantage with OPCAB in terms of patient morbidity assessed in terms of mortality, transfusion, perioperative MI, stroke, new atrial fibrillation, sternal wound infection, or length of hospitalization. Similar conclusions were reached by Gerola et al.49
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References |
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1. Kirklin JK, Westaby S, Blackstone EH, et al. Complement and the damaging effects of cardiopulmonary bypass. J Thorac Cardiovasc Surg. 1983; 86: 845–857.[Abstract]
2. Paparella D, Yau TM, Young E. Cardiopulmonary bypass induced inflammation: pathophysiology and treatment: an update. Eur J Cardiothorac Surg. 2002; 21: 232–244.
3. Taggart DP, Westaby S. Neurological and cognitive disorders after coronary artery bypass grafting. Curr Opin Cardiol. 2001; 16: 271–276.[CrossRef][Medline] [Order article via Infotrieve]
4. Magee MJ, Jablonski KA, Stamou SC, et al. Elimination of cardiopulmonary bypass improves early survival for multivessel coronary artery bypass patients. Ann Thorac Surg. 2002; 73: 1196–1202.
5. Plomondon ME, Cleveland JC Jr, Ludwig ST, et al. Off-pump coronary artery bypass is associated with improved risk-adjusted outcomes. Ann Thorac Surg. 2001; 72: 114–119.
6. Cleveland JC Jr, Shroyer AL, Chen AY, et al. Off-pump coronary artery bypass grafting decreases risk-adjusted mortality and morbidity. Ann Thorac Surg. 2001; 72: 1282–1288.
7. Brown PP, Mack MJ, Simon AW, et al. Outcomes experience with off-pump coronary artery bypass surgery in women. Ann Thorac Surg. 2002; 74: 2113–2119.
8. Zamvar V, Williams D, Hall J, et al. Assessment of neurocognitive impairment after off-pump and on-pump techniques for coronary artery bypass graft surgery: prospective randomised controlled trial. BMJ. 2002; 325: 1268.
9. Diegeler A, Hirsch R, Schneider F, et al. Neuromonitoring and neurocognitive outcome in off-pump versus conventional coronary bypass operation. Ann Thorac Surg. 2000; 69: 1162–1166.
10. van Dijk D, Jansen EW, Hijman R, et al. Cognitive outcome after off-pump and on-pump coronary artery bypass graft surgery: a randomized trial. JAMA. 2002; 287: 1405–1412.
11. Lloyd CT, Ascione R, Underwood MJ, et al. Serum S-100 protein release and neuropsychologic outcome during coronary revascularization on the beating heart: a prospective randomized study. J Thorac Cardiovasc Surg. 2000; 119: 148–154.
12. Sharony R, Bizekis CS, Kanchuger M, et al. Off-pump coronary artery bypass grafting reduces mortality and stroke in patients with atheromatous aortas: a case control study. Circulation. 2003; 108 (suppl II): II-15–II-20.[Medline] [Order article via Infotrieve]
13. Stamou SC, Jablonski KA, Pfister AJ, et al. Stroke after conventional versus minimally invasive coronary artery bypass. Ann Thorac Surg. 2002; 74: 394–399.
14. Patel NC, Deodhar AP, Grayson AD, et al. Neurological outcomes in coronary surgery: independent effect of avoiding cardiopulmonary bypass. Ann Thorac Surg. 2002; 74: 400–405.
15. Sabik JF, Gillinov AM, Blackstone EH, et al. Does off-pump coronary surgery reduce morbidity and mortality? J Thorac Cardiovasc Surg. 2002; 124: 698–707.
16. Ascione R, Lloyd CT, Underwood MJ, et al. On-pump versus off-pump coronary revascularization: evaluation of renal function. Ann Thorac Surg. 1999; 68: 493–498.
17. Arom KV, Flavin TF, Emery RW, et al. Safety and efficacy of off-pump coronary artery bypass grafting. Ann Thorac Surg. 2000; 69: 704–710.
18. Mishra M, Malhotra R, Mishra A, et al. Hemodynamic changes during displacement of the beating heart using epicardial stabilization for off-pump coronary artery bypass graft surgery. J Cardiothorac Vasc Anesth. 2002; 16: 685–690.[CrossRef][Medline] [Order article via Infotrieve]
19. Sepic J, Wee JO, Soltesz EG, et al. Cardiac positioning using an apical suction device maintains beating heart hemodynamics. Heart Surg Forum. 2002; 5: 279–284.[Medline] [Order article via Infotrieve]
20. Mueller XM, Chassot PG, Zhou J, et al. Hemodynamics optimization during off-pump coronary artery bypass: the "no compression" technique. Eur J Cardiothorac Surg. 2002; 22: 249–254.
21. Soltoski P, Salerno T, Levinsky L, et al. Conversion to cardiopulmonary bypass in off-pump coronary artery bypass grafting: its effect on outcome. J Card Surg. 1998; 13: 328–334.[Medline] [Order article via Infotrieve]
22. Couture P, Denault A, Limoges P, et al. Mechanisms of hemodynamic changes during off-pump coronary artery bypass surgery. Can J Anaesth. 2002; 49: 835–849.[Medline] [Order article via Infotrieve]
23. Grundeman PF, Borst C, van Herwaarden JA, et al. Vertical displacement of the beating heart by the octopus tissue stabilizer: influence on coronary flow. Ann Thorac Surg. 1998; 65: 1348–1352.
24. Gandra SM, Rivetti LA. Experimental evidence of regional myocardial ischemia during beating heart coronary bypass: prevention with temporary intraluminal shunts. Heart Surg Forum. 2002; 6: 10–18.[Medline] [Order article via Infotrieve]
25. Rivetti LA, Gandra SM. An intraluminal shunt for off-pump coronary artery bypass grafting: report of 501 consecutive cases and review of the technique. Heart Surg Forum. 1998; 1: 30–36.[Medline] [Order article via Infotrieve]
26. Rivetti LA, Gandra SM. Initial experience using an intraluminal shunt during revascularization of the beating heart. Ann Thorac Surg. 1997; 63: 1742–1747.
27. Lucchetti V, Capasso F, Caputo M, et al. Intracoronary shunt prevents left ventricular function impairment during beating heart coronary revascularization. Eur J Cardiothorac Surg. 1999; 15: 255–259.
28. Izutani H, Gill IS. Acute graft failure caused by an intracoronary shunt in minimally invasive direct coronary artery bypass grafting. J Thorac Cardiovasc Surg. 2003; 125: 723–724.
29. Arai H, Yoshida T, Izumi H, et al. External shunt for off-pump coronary artery bypass grafting: distal coronary perfusion catheter. Ann Thorac Surg. 2000; 70: 681–682.
30. Puskas JD, Thourani VH, Vinten-Johansen J, et al. Active perfusion of coronary grafts facilitates complex off-pump coronary artery bypass surgery. Heart Surg Forum. 2001; 4: 65–68.[Medline] [Order article via Infotrieve]
31. Vassiliades TA Jr, Nielsen JL, Lonquist JL. Coronary perfusion methods during off-pump coronary artery bypass: results of a randomized clinical trial. Ann Thorac Surg. 2002; 74: S1383–S1389.
32. Kamiya H, Watanabe G, Doi T, et al. A coronary active perfusion system for off-pump coronary artery bypass: advantage over passive perfusion regarding the physiology of the coronary artery. ASAIO J. 2002; 48: 658–664.[CrossRef][Medline] [Order article via Infotrieve]
33. Cooper WA, Corvera JS, Thourani VH, et al. Perfusion-assisted direct coronary artery bypass provides early reperfusion of ischemic myocardium and facilitates complete revascularization. Ann Thorac Surg. 2003; 75: 1132–1139.
34. Diegeler A, Matin M, Falk V, et al. Indication and patient selection in minimally invasive and off-pump coronary artery bypass grafting. Eur J Cardiothorac Surg. 1999; 16: S79–S82.
35. de Carvalho LR, Escobar M, Lobo Filho JG. Patient selection in off-cardiopulmonary bypass revascularization. Heart Surg Forum. 2002; 5: 229–233.[Medline] [Order article via Infotrieve]
36. Magee MJ, Coombs LP, Peterson ED, et al. Patient selection and current practice strategy for off-pump coronary artery bypass surgery. Circulation. 2003; 108 (suppl II): II-9–II-14.[Medline] [Order article via Infotrieve]
37. van Dijk D, Nierich AP, Jansen EW, et al. Early outcome after off-pump versus on-pump coronary bypass surgery: results from a randomized study. Circulation. 2001; 104: 1761–1766.
38. Angelini GD, Taylor FC, Reeves BC, et al. Early and midterm outcome after off-pump and on-pump surgery in Beating Heart Against Cardioplegic Arrest Studies (BHACAS 1 and 2): a pooled analysis of two randomised controlled trials. Lancet. 2002; 359: 1194–1199.[CrossRef][Medline] [Order article via Infotrieve]
39. Nathoe HM, van Dijk D, Jansen EW, et al. A comparison of on-pump and off-pump coronary bypass surgery in low-risk patients. N Engl J Med. 2003; 348: 394–402.
40. Puskas JD, Williams WH, Duke PG, et al. Off-pump coronary artery bypass grafting provides complete revascularization with reduced myocardial injury, transfusion requirements, and length of stay: a prospective randomized comparison of two hundred unselected patients undergoing off-pump versus conventional coronary artery bypass grafting. J Thorac Cardiovasc Surg. 2003; 125: 797–808.
41. Gundry SR, Romano MA, Shattuck OH, et al. Seven-year follow-up of coronary artery bypasses performed with and without cardiopulmonary bypass. J Thorac Cardiovasc Surg. 1998; 115: 1273–1277.
42. Drenth DJ, Veeger NJ, Winter JB, et al. A prospective randomized trial comparing stenting with off-pump coronary surgery for high-grade stenosis in the proximal left anterior descending coronary artery: three-year follow-up. J Am Coll Cardiol. 2002; 40: 1955–1960.
43. Sharony R, Grossi EA, Saunders PC. Propensity case match analysis of off-pump CABG in patients with atheromatous aortic disease. Presented at the 83rd annual meeting of the American Association for Thoracic Surgery, Boston, Mass, April 5, 2003.
44. Al Ruzzeh S, Nakamura K, Athanasiou T, et al. Does off-pump coronary artery bypass (OPCAB) surgery improve the outcome in high-risk patients? A comparative study of 1398 high-risk patients. Eur J Cardiothorac Surg. 2003; 23: 50–55.
45. Shennib H. A renaissance in cardiovascular surgery: endovascular and device-based revascularization. Ann Thorac Surg. 2001; 72: S993–S994.
46. Tozzi P, Corno AF, von Segesser LK. Sutureless coronary anastomoses: revival of old concepts. Eur J Cardiothorac Surg. 2002; 22: 565–570.
47. Khan NE, De Souza A, Mister R, et al. A randomized comparison of off-pump and on-pump multivessel coronary-artery bypass surgery. N Engl J Med. 2004; 350: 21–28.
48. Legare JF, Buth KJ, King S, et al. Coronary bypass surgery performed off pump does not result in lower in-hospital morbidity than coronary artery bypass grafting on pump. Circulation. 2004; 109: 887–892.
49. Gerola LR, Buffolo E, Jasbik W, et al. Off-pump versus on-pump myocardial revascularization in low-risk patients with one or two vessel disease: perioperative results in a multicenter randomized controlled trial. Ann Thorac Surg. 2004; 77: 569–573.
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