Technical aspects of modern coronary artery bypass surgery

Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery Technical Aspects of Modern Coronary Artery Bypass Surgery

C H A P T E R Closing the gap between best evidence and common practice in surgical coronary revascularization: The rationale for superspecialization John D Puskas1 and David P Taggart2,3 Department of Cardiovascular Surgery, Mount Sinai Morningside, New York, NY, United States 2Department of Cardiovascular Surgery, University of Oxford, Oxford, United Kingdom Consultant Cardiac Surgeon, Oxford University Hospitals, Oxford, United Kingdom Everybody is against specialization except the patient Francis D Moore (Surgeon Scientist) 1913 2001 In an effort to improve outcomes for patients with valvular heart disease, there has been a concerted push over the past decade toward the creation of “Heart Valve Centers” or “Heart Valve Reference Centers.” In 2017 the European Society of Cardiology and European Association for Cardiothoracic Surgery even jointly published a document outlining the standards that would define such a center [1] The same year, six North American professional organizations preeminent in the fields of Cardiac Surgery, Interventional Cardiology, Anesthesiology and Echocardiography published a Systems of Care Document, entitled A Proposal to Optimize Care for Patients with Valvular Heart Disease These same organizations recently published an update [2], stating that their document was necessary because “providing optimal care to patients with valvular heart disease is an increasingly complex process, starting with early recognition and diagnosis MDT assessment, shared decision-making, and long-term follow-up.” They also note, “there are an increasing number of treatment options available to patients with valvular heart disease; yet not all patients are aware of or have access to the full spectrum of interventions.” The authors go on to propose an improved system of care for patients at valvular heart disease centers, whose primary goal is to optimize outcomes for all patients They argue that the “case for centers with the ability to offer more comprehensive care is logical.” The authors state their intent is “to set performance and Technical Aspects of Modern Coronary Artery Bypass Surgery DOI: https://doi.org/10.1016/B978-0-12-820348-4.00001-7 © 2021 Elsevier Inc All rights reserved Closing the gap between best evidence and common practice quality goals for a valve center to meet benchmarks to be considered either comprehensive or primary in a manner that would be more objective than simple self-designation.” There are few who would argue with such sentiments, motivation, and logic Of course, that then begs the question: why the same statements not also apply equally well to patients with ischemic heart disease? Yet the stark reality is that no similar joint multinational or multidisciplinary proposal has ever been undertaken or even suggested for patients with ischemic heart disease This is truly remarkable and counterintuitive, especially considering that vastly more patients in the developed world undergo procedures to treat coronary artery disease than valvular heart disease Although the 2014 ESC/EACTS guidelines on myocardial revascularization [3] recommend to “perform [CABG] procedures in a hospital structure and by a team specialized in cardiac surgery, using written protocols” (Class I, LOE B), they stop well short of recommending any special training, team, or focus on surgical coronary revascularization The STS Adult Cardiac Surgery Database 2019 update on outcomes and quality [4] makes clear that the majority of all adult cardiac surgical procedures performed in North America is isolated coronary artery bypass grafting (CABG) (55%), while CABG plus mitral valve (MV) or aortic valve (AV) procedures comprise an additional 8% of all procedures; thus while isolated MV or AV procedures cumulatively account for 16% of all procedures, CABG makes up 63% of all procedures recorded in the contemporary STS database Not only does CABG make up the large majority of all procedures performed by adult cardiac surgeons but also it continues to be performed by much the same techniques that were developed 40 years ago Full sternotomy with aortic cannulation and clamping for cardioplegic arrest and bypass with a single internal thoracic artery graft to the left anterior descending coronary artery plus reversed saphenous vein grafts (SVGs) to all non-left anterior descending (LAD) coronary targets, remaining the most commonly performed procedure in cardiothoracic surgery While this is an excellent and well-proven option for many patients, it does not mean that it is the best option for all patients It ignores the fact that aortic manipulation is the single most important contributor to perioperative stroke and that SVGs have 50% rate of failure at 10 years For more than three decades it has been repeatedly demonstrated that arterial grafts have much superior angiographic patency rates when compared to vein grafts over the long term Numerous authors have reported superior survival, major adverse cardiovascular events-free survival, and intervention-free survival with multiple arterial conduits compared to a single internal thoracic artery (ITA)-LAD graft plus SVGs, since the seminal report by Lytle et al [5] This has been shown to be true even in diabetic patients, in whom the provision of bilateral internal thoracic arteries (BITA) grafting rather than single internal thoracic artery (SITA) grafting confers a greater survival benefit than SITA grafting in nondiabetic patients [6] Despite these compelling data, the use of bilateral ITA grafting remains less than 6% in the United States [7] An insightful analysis of intraoperative conversion from planned BITA to SITA grafting in the arterial revascularization trial (ART) suggests that even self-selected surgeons have highly variable expertise in deploying BITA conduits, despite having performed a large number of Technical Aspects of Modern Coronary Artery Bypass Surgery Closing the gap between best evidence and common practice CABG procedures in their careers In this report the overall rate of unintentional conversion from BITA to SITA was 14% and ranged from 0% to 100% among individual surgeons and 0% 49% for individual surgical centers [8] In the ART trial, patients who actually received more than one arterial conduit enjoyed significantly better 10 years survival and a significantly lower incidence of death/myocardial infarction/stroke than those who received a single arterial conduit [9] Gaudino and colleagues reported a metaanalysis of pooled patient-level data from six previous prospective randomized trials comparing outcomes after CABG with LITA-LAD plus SVGs (single arterial conduit) versus LITA-LAD plus at least one radial artery graft (multiple arterial conduits) This dataset confirmed that death/myocardial infarction/ repeat revascularization was less frequent when a radial artery graft was included (typically grafted to the second most important coronary target), driven by a significant reduction in graft failure among radial conduits [10] Ten-year follow-up of these same patients has yielded similar findings with the continued divergence of these curves in favor of multiple arterial grafting [11] Despite this and many other reports of superior graft patency and improved clinical outcomes with radial artery grafting, less than 7% of isolated CABG cases in the United States currently include a radial artery conduit [7] The combination of BITA grafting and radial artery grafting allows total arterial revascularization (TAR), which has been shown to confer a long-term benefit in terms of symptom relief and survival [12] Regrettably, TAR accounts for approximately 1% 2% of all multivessel CABG procedures worldwide The evidence that minimizing aortic manipulation can significantly reduce the incidence of stroke has been well documented over decades of practice Most recently, Zhao and colleagues reported a network metaanalysis of 13 studies, including 37,720 patients, comparing outcomes with four alternative CABG techniques, namely, traditional on-pump CABG, offpump CABG (OPCAB) with a partial aortic clamp for proximal anastomoses, OPCAB with a clampless facilitating device for proximal anastomoses, and OPCAB with a no-aortic-touch (an-aortic) technique in which all graft inflow was from in situ BITA conduits They reported that an-aortic OPCAB was associated with a hazard ratio of 0.22 for stroke, 0.50 for mortality, 0.73 for myocardial infarction, compared to traditional CABG Indeed, the relative risk of virtually every adverse event correlated with the extent of aortic manipulation in the surgical technique chosen as shown in Fig 1.1 [13] Perhaps due to the technical challenges that this surgical strategy entails, aortic TAR accounts for ,1% of all CABG procedures worldwide Intraoperative assessment of graft patency is routine in every vascular surgical procedure except CABG Transit-time flow measurement has been available for more than 20 years but is presently used in less than 20% of CABG cases in the United States It has been shown to detect imperfect or failed grafts whose poor flow is otherwise not clinically apparent in the operating room [14] So, why does the gap between best evidence and clinical practice in CABG not only persist but also that may even be widening? Why is this tolerated by cardiac surgeons and cardiologists? The answers to these questions are necessarily subjective and cannot be confirmed There are, however, a number of plausible reasons Technical Aspects of Modern Coronary Artery Bypass Surgery Closing the gap between best evidence and common practice FIGURE 1.1 A network metaanalysis demonstrating progressively improved clinical results with coronary bypass techniques that entail progressively less aortic manipulation [13] (A) Stroke, (B) mortality, (C) myocardial infarction, (D) renal failure, (E) bleeding, and (F) atrial fibrillation First, literally all of the quality metrics for which surgeons and hospitals are held accountable are based on 30-day outcomes; it is obvious that the conventional SITA-plusSVGs CABG approach can yield very good 30-day results in many/most patients while the benefit of the more technically challenging multiple arterial conduits will not become apparent until much later follow-up Second, most training programs continue to teach the conventional SITA-plus-SVGs CABG operation to virtually all trainees in a manner that has not changed meaningfully for more than three decades Hands-on training in even relatively simple techniques such as skeletonized harvest of BITA conduits is uncommon, yet facility with skeletonized BITA harvest is, arguably, the most important stepping-stone to virtually all advanced surgical coronary revascularization Radial artery conduits can be harvested very safely, quickly, and reliably by endoscopic techniques, but these skills are possessed by few surgical assistants and even fewer surgeons Training in skeletonized BITA harvest and endoscopic harvest of radial arteries remains a challenge that has not been emphasized by our professional bodies and, possibly as a consequence, being imperfectly met by industry Technical Aspects of Modern Coronary Artery Bypass Surgery Closing the gap between best evidence and common practice Similarly, the adoption of OPCAB has stalled and even receded, despite the numerous potential benefits of the procedure, in part because comprehensive training in the technical nuances that make the OPCAB approach reliable and reproducible has never been made widely available or supported Industry support for improvement in instruments to facilitate OPCAB has also stalled Poorly trained and equipped surgeons have sometimes performed imprecise OPCAB procedures, with mixed clinical results [15], while series reported by expert OPCAB surgeons have shown excellent clinical outcomes [16 19] The STS database reveals that there are approximately 1150 cardiac surgery programs in the United States, employing 2676 cardiac surgeons and performing 160,000 CABG operations per year This amounts, on average, to 139 CABG cases per center per year and approximately one CABG case per surgeon per week It is well known that there exists a volume quality relationship for complex procedures of many types and across many industries, especially those dependent on skilled teamwork Indeed, in other surgical fields such as orthopedics and neurosurgery superspecialization in a limited repertoire of procedures is the norm Similarly, our own field has endorsed the need for specialists in AV and MV disease, major aortic disease, and the surgical management of heart failure; trainees expect to enter these superspecialties after completing an additional year(s) of structured training Acknowledging the obvious fact that the margin for tolerable error in suture placement for a valvular or aortic procedure is on the order of mm and for a coronary anastomosis is on the order of 0.1 0.5 mm brings the greater technical difficulty of coronary surgery into sharp focus Oddly, however, it is the less technically demanding, less common procedures in our specialty that have received the greater focus on superspecialization, while surgical coronary revascularization is widely considered a “commodity” suitable for every cardiac surgeon to perform with no additional training Indeed it is often dismissed as “just another CABG.” It is, therefore, also possible that a major impediment to consistent excellence in CABG is that there are simply too many surgeons each performing too few CABG procedures It is intuitive and plausible that concentrating the experience of a larger number of CABG cases in the hands of fewer cardiac surgeons and surgical teams would promote the advancement of the field This could be the natural consequence of designating surgical coronary revascularization a superspecialty within cardiothoracic surgery However, it may not be necessary to redistribute CABG cases in order to promote innovation and improve quality in CABG surgery Simply adding the provision of multiple arterial grafts and avoidance of aortic manipulation to our quality metrics and providing additional remittance for intraoperative graft assessment would certainly change surgeon behavior and improve surgical coronary revascularization Of course, formal endorsement by our professional bodies of a clinical training pathway to superspecialization in CABG, analogous to the additional training typically expected of surgeons intending to specialize in aortic surgery or transplantation/management of heart failure, would be the most effective way to systematically improve the quality of training in surgical coronary revascularization and thus the quality of CABG surgery provided to patients While not every cardiac surgeon who performs CABG would need to complete such an additional year(s) of training, every major department should have at least one surgeon who has a committed focus on the surgical management of coronary artery disease This must include a commitment Technical Aspects of Modern Coronary Artery Bypass Surgery Closing the gap between best evidence and common practice to a comprehensive Heart Team approach, with shared decision-making, adherence to guidelines and appropriateness criteria, public reporting of outcomes, participation in research trials, and training and education [20] Focused educational efforts dedicated to the state of the art in surgical coronary revascularization are sorely needed and should be strongly supported by all professional bodies in cardiothoracic surgery and especially cardiology The International Coronary Congress (www.internationalcoronarycongress.com) is the only international symposium dedicated annually to identifying the best practices in CABG and promulgating them worldwide Regrettably, textbooks in the field of cardiac surgery have typically included a single chapter for CABG, while devoting a similar amount of space to each of numerous niche procedures The first major comprehensive textbook on state-of-the-art surgical coronary revascularization will be published this year by Oxford University Press, and the present textbook of surgical techniques in CABG published by Elsevier is another important step forward References [1] Chambers JB, Prendergast B, Lung B, Rosenhek R, Zamorano JL, Pierard LA, et al Standards defining a “Heart Valve Centre”: ESC working group on valvular heart disease and European Association of Cardiothoracic Surgery Viewpoint Eur J Cardio-Thoracic Surg 2017;52:418 24 [2] Nishimura RA, O’Gara PT, Bavaria JE, Brindis RG, Carroll JD, Kavinsky CJ, et al AATS/ACC/ASE/SCAI/ STS expert consensus systems of care document: a proposal to optimize care for patients with valvular heart disease: a joint report of the American Association for Thoracic Surgery, American College of Cardiology, American Society of Echocardiography, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons Catheter Cardiovasc Interv 2018;2019 Available from: https://doi.org/ 10.1002/ccd.28196 [3] Eur Heart J 2014;35:2541 619 https://doi.org/10.1093/eurheartj/ehu278 [4] D’Agostino RS, Jacobs JP, Badhwar V, Fernandez FG, Paone G, Wormuth DW, et al The society of thoracic surgeons adult cardiac surgery database: 2019 update on outcomes and quality Ann Thorac Surg 2019;107:24 32 [5] Lytle BW, Blackstone EH, Loop FD, Houghtaling PL, Arnold JH, Akhrass R, et al Two internal thoracic artery grafts are better than one J Thorac Cardiovasc Surg 1999;117(5) [6] Puskas, et al Bilateral internal thoracic artery grafting is associated with significantly improved long-term outcomes even among diabetic patients Ann Thorac Surg 2012;94:710 16 [7] Gaudino M, Chikwe J, Falk V, Lawton JS, Puskas JD, Taggart DP Transatlanticeditorial: the use of multiple arterial grafts for coronary revascularization inEurope and North America Eur J Cardiothorac Surg 2020;57 (6):1032 1037 Available from: https://doi.org/10.1093/ejcts/ezaa077 [8] Benedetto U, Altman DG, Flather M, Gerry S, Gray A, Lees B, et al Incidence and clinical implications of intraoperative bilateral internal thoracic artery graft conversion: insights from the arterial revascularization trial J Thorac Cardiovasc Surg 2018;155 [9] Taggart DP, Benedetto U, Gerry S, et al Bilateral versus single internal-thoracic-artery grafts at 10 years N Engl J Med 2019;380:437 46 [10] Gaudino M, Benedetto U, Fremes S, Biondi-Zoccai G, Stat M, Sedrakyan A, et al Radial artery of saphenous vein grafts in coronary artery bypass surgery NEJM 2018;1 Available from: https://doi.org/10.1056/ NEJMoal716026 [11] Gaudino M, Benedetto U, Fremes S, et al Association of Radial Artery Graft vs Saphenous Vein Graft With Long-term Cardiovascular Outcomes Among Patients Undergoing Coronary Artery Bypass Grafting: A Systematic Review and Meta-analysis JAMA 2020;324(2):179 187 [12] Tatoulis J, Wynne R, Skillington PD, Buxton BF Total arterial revascularization: achievable and prognostically effective—a multicenter analysis Ann Thorac Surg 2015;100:1268 75 Technical Aspects of Modern Coronary Artery Bypass Surgery Closing the gap between best evidence and common practice [13] Zhao DF, Edelman J, Seco M, Bannon PG, Wilson MK, Byrom MJ, et al Coronary artery bypass grafting with and without manipulation of the ascending aorta A network meta-analysis J Am Coll Cardiol 2017;69(8) [14] Taggart DP, Thuijs DJFM, Di Giammarco G, Puskas JD, Wendt D, Trachiotis GD, et al Intraoperative transittime flow measurement and high-frequency ultrasound assessment in coronary artery bypass grafting J Thorac Cardiovasc Surg 2020;159:1283 92 [15] Shroyer AL, Grover FL, Hattler B, Collins JF, McDonald GO, Kozora E, et al On-pump versus off-pump coronary artery bypass surgery N Engl J Med 2009;361:1827 37 [16] Puskas JD, Williams WH, Mahoney EM, Huber PR, Block PC, Duke PG, et al Off-pump vs conventional coronary artery bypass grafting: early and 1-year graft patency, cost and quality-of-life outcomes JAMA 2004;291:1841 [17] Puskas JD, Williams WH, O’Donnell R, Patterson RE, Sigman SR, Smith AS, et al Off-pump and on-pump coronary artery bypass grafting are associated with similar graft patency, myocardial ischemia and freedom from reintervention: long-term follow-up of a randomized trial Ann Thorac Surg 2011;91:1836 43 [18] Diegeler A, Borgermann J, Kappert U, Hilker M, Doenst T, Boning A, et al Five-year outcome after off-pump or on-pump coronary artery bypass grafting in elderly patients Circulation 2019;139:1865 71 [19] Lamy A, Devereaux PJ, Prabhakaran D, Taggart DP, Hu S, Straka Z, et al Five-year outcomes after off-pump or on-pump coronary artery bypass grafting N Engl J Med 2016;375:2359 68 [20] Mack M, Taggart D Coronary revascularization should be a subspecialty focus in cardiac surgery J Thorac Cardiovasc Surg 2019;157:945 Technical Aspects of Modern Coronary Artery Bypass Surgery C H A P T E R Surgical strategy in multiple arterial grafting Mario Gaudino Department of Cardiothoracic Surgery, Weill Cornell Medicine, New York, NY, United States Failing to plan is planning to fail Benjamin Franklin The importance of the strategy and good clinical sense While the cutting-and-sewing part of coronary surgery is important, the real key to a successful outcome is the surgical strategy It is important to keep in mind that: Percutaneous coronary interventions have very high periprocedural safety, and the results become inferior to surgery only in the midterm and only if the operative risk for surgery is very low The traditional coronary artery bypass grafting (CABG) operation [internal thoracic artery (ITA) and veins] is extremely safe and highly reproducible The available data not clearly prove a survival advantage with the use of multiple arterial grafts (MAG) and suggest that the difference in favor of the MAG strategy, if existent, is moderate and becomes evident only in the mid- to long-term follow-up Due to these considerations, it is my belief that MAG should be used only if the operative risk is not increased by its adoption In fact, I not believe that the available evidence justifies any increase in operative mortality and risk of major complications with adding one or more arterial grafts to the ITA The risk/benefit ratio of the use of MAG is dependent not only on patients’ characteristics but also, and critically, on the experience of the operating surgeon and of the operating team [1,2] It is key that the surgeon knows all the available technical solutions, but also that he or she has a realistic idea of his/her own skills and the experience of the team to be able to individualize the operation to the patient, the surgeon, and the setting Technical Aspects of Modern Coronary Artery Bypass Surgery DOI: https://doi.org/10.1016/B978-0-12-820348-4.00002-9 © 2021 Elsevier Inc All rights reserved 10 Surgical strategy in multiple arterial grafting In general, my advice is to err on the side of safety and privilege clinical outcomes over the surgeon’s ego and technique An alive patient with ITA and veins is a very good result, but a catastrophe after a complex all-arterial bypass operation is not The radial artery is more surgeon-friendly and reliable than the right ITA [3], individual grafts are easier than Y or T grafts, and sequentials have better hemodynamics but require more attention and time All this is even more evident when operating on the beating heart Those simple concepts have been the foundation of my grafting strategy in the last two decades Indications for the use of arterial grafts As explained earlier, while the use of MAG should be considered in every patient, the risk/benefit ratio must be carefully evaluated in light of the available evidence and of the operating surgeon’s experience It is important to remind that while we have data to suggest improvement in clinical outcomes with the addition of a second arterial graft, there is very little evidence to support a further benefit for three or more arterial grafts or total arterial revascularization, as treatment allocation bias is the likely explanation for the difference seen in the observational series [4] I am typically reluctant to use MAG for combined cases and in emergency or unstable situations except in very young patients with excellent cardiac function If the team is experienced, harvesting of the radial artery does not take longer than harvesting of a saphenous vein and can be considered, although the possible prolonged need for vasopressor may raise concerns of graft spasm I never use the right ITA in unstable cases A classical debate among coronary surgeons is the stenosis cutoff acceptable for arterial grafts The evidence on the detrimental effect of chronic coronary competitive flow on arterial grafts is relatively solid [5] The radial and gastroepiploic artery are much less tolerant than the ITA, and the left anterior descending (LAD) territory is much more forgiving than the others (especially the right coronary artery territory) The impact of preoperative fractional flow reserve (FFR) on arterial bypass graft anastomotic function (IMPAG) trial has shown that an FFR cutoff of 0.78 is associated with 97% anastomotic function of arterial grafts at months [6] The cutoff is higher (0.81) for sideto-side anastomosis and lower (0.71) for the right coronary artery [7] However, most of the patients referred for surgery not have FFR data, especially for the circumflex and right coronary distribution The degree of stenosis is of very limited utility because the same percentage of stenosis may have very different consequences in terms of residual flow based on the diameter of the vessel If FFR data are not available, I base my decisions on the ratio between the diameter of the conduit and the diameter of the residual lumen of the target vessel and generally accept a ratio of 1.2 or above Another important consideration is the graft configuration, as aorta-anastomosed grafts are less affected by competitive flow than in situ and Y grafts Technical Aspects of Modern Coronary Artery Bypass Surgery 11 Aorta-based or internal thoracic artery based grafts? A classic face-off: right internal thoracic artery or radial artery? As the left ITA is the cornerstone of CABG, the instinctive second arterial graft for many surgeons is the right ITA While the right ITA is a superb conduit (and my first choice for young patients), some points need to be made: The level and amount of the evidence supporting improved patency rate, and clinical outcomes compared to the saphenous vein are by far higher for the radial artery than for the right ITA (the latter is in fact a class I indication in myocardial revascularization guidelines, while the former is a class II [8]) (Fig 2.1) The radial artery is much easier to manipulate and to sew Surgeon’s experience and confidence with arterial grafts are much more important for the outcome of the right ITA than of the radial artery grafts [3] Because of its superior length and diameter, the radial artery allows much more freedom in terms of graft configuration and number of anastomoses The two considerations to be made when selecting which second arterial graft to use are the surgeon’s experience and the complexity of the grafting strategy For surgeons with limited experience and for complex graft configurations (multiple sequentials, distal targets, etc.), the radial artery is a better option (Fig 2.2) For simple grafting strategies and for surgeons with considerable experience in MAG, the right ITA is a good alternative There are clinical or anatomic situations that clearly indicate the use of one of the two conduits: the right ITA is better in case of moderate stenosis of the target vessel and the radial artery is better in patients at high risk of sternal wound complications Aorta-based or internal thoracic artery based grafts? The ITA is a third-order artery and has a dp/dt lower than the coronary arteries, while aorta-based grafts have hemodynamics more similar to the coronary arteries Angiographic randomized trials comparing the saphenous vein versus the radial or right internal thoracic artery FIGURE 2.1 Comparative evidence: the radial artery versus the saphenous vein and right internal thoracic artery versus saphenous vein RA versus SV RCTs Dreifaildt 2013 Gaudino 2005 Munereo 2004 Petrovic 2012 RAPCO 2003 RAPS 2000 RVSP 2008 Song 2012 VACSP 2011 2366 paents RITA versus SV RCTs Gaudino 2005 Kim 2014 304 paents Technical Aspects of Modern Coronary Artery Bypass Surgery