Asian Cardiovasc Thorac Ann 2003;11:107-112
© 2003 Asia Publishing EXchange Ltd
Total Arterial Revascularization on Beating Heart: Experience in 803 Cases
Sushil Kumar Singh, MCh,
Surya Kumar Mishra, MCh,
Deepak Kumar, MD,
Ram Deo Yadave, DM,
Rajiv Agarwal, DM,
Subhash Kumar Sinha, MCh
Department of Cardiology & Cardiothoracic Surgery, Batra Hospital & Medical Research Centre, New Delhi, India
For reprint information contact: Subhash K Sinha, MCh Tel: 91 11 608 6951 Fax: 91 11 608 7661 email: sksinha{at}del3.vsnl.net.in Batra Hospital & Medical Research Centre, M.B. Road, New Delhi 110 0062, India.
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ABSTRACT
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To avoid the deleterious effects of cardiopulmonary bypass, total arterial revascularization was performed on the beating heart, using an Octopus stabilizer, in this prospective study of 803 patients without selection bias. Single-vessel disease was present in 71 (9%) patients, double-vessel disease in 204 (25%), and triple-vessel disease in 528 (66%). An ejection fraction < 30% was found in 127 (16%) cases. Angiography was carried out before discharge in 204 (25%) patients. Grafts included left and right internal mammary arteries and the radial artery. There were 2,661 grafts placed with a mean of 3.31 grafts per patient (range, 1 to 6). Operative mortality was 0.5%. There was no postoperative stroke and few incidences of renal impairment, even in patients with chronic renal failure. Blood transfusion was not required in 558 (69%) patients. Mean hospital stay was 5.6 days. Overall angiographic patency was 98.6%. Total arterial revascularization on the beating heart was found to be safe, effective, and reproducible in almost all patients, with excellent short-term patency rates and minimal morbidity.
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INTRODUCTION
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Coronary artery bypass grafting (CABG) is the most effective treatment for symptomatic triple-vessel coronary disease, provided the graft and distal native vessel remain free of obstruction. Cardiopulmonary bypass (CPB) has been linked to a systemic inflammatory response involving multiple organ systems.1 Keeping the heart beating during CABG eliminates this reaction. Decreased operative mortality, less perioperative myocardial infraction, shorter hospital stay, and cost effectiveness are the most commonly reported advantages.2 Borst and colleagues3 developed a mechanical suction stabilization system (Octopus; Medtronic, Inc., Minneapolis, MN, USA) and using the pig model, they showed minimal arrhythmias, little superficial histologic change related to the suction, and an excellent and reproducible reduction of cardiac surface motion for CABG. Numerous reports have documented high rates of late failure of saphenous vein grafts, resulting in angina, infarction, or death.4 The pedicled left internal mammary artery-to-left anterior descending artery graft has shown excellent late patency and long-term survival.4 Although many surgeons doubted the ability of the internal mammary artery (IMA) to deliver adequate flow even to a single coronary artery, it was found that the meticulously prepared and anastomosed IMA has sufficient flow to supply the entire myocardium.5,6 This extended the use of IMA to bypass as many coronary arteries as possible with a combination of bilateral attached and free IMA, sequential bypass grafts, and Y-grafts.5,7 This report describes surgical results during a period of transition from CABG with CPB and few arterial conduits, to beating-heart total arterial revascularization using the Octopus device.
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PATIENTS AND METHODS
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In the 24 months from January 2000 to December 2001, total arterial revascularization on the beating heart was performed in 803 of 892 CABG operations (90%). Of the 89 patients excluded, 28 received a saphenous vein graft for various reasons (IMA damage during harvesting, diseased radial artery, inadequate length of conduit) and 61 required CPB for concomitant procedures (valve, heart defect, or aneurysm repair). In the initial period (learning curve) there was careful selection of patients for beating-heart CABG; with more experience, it was extended and in the later period, no patient was excluded on the basis of surgical urgency, high risk, reoperation, age, sex, or obesity (Figure 1
). The left IMA (LIMA) was used to revascularize the left anterior descending artery (LAD) in all cases, and the right IMA was used for the right coronary and proximal posterior descending artery. For marginal and distal posterior descending artery lesions, radial artery conduit was rotated after making a Y-graft with the LIMA and sequentially anastomosed to these vessels. The demographic and clinical profiles are shown in Table 1. Preoperatively, all patients underwent coronary angiography and echocardiography to evaluate coronary anatomy and left ventricular function. In the initial phase of the study, total arterial CABG on the beating heart was avoided if the diseased vessel had a diameter 
1.5 mm or an intramyocardial course, if the patient had cardiomegaly, a low ejection fraction, left main disease, or hemodynamic instability, and when there was an inadequate length of suitable conduit. After a few months of experience, only patients with inadequate conduits or those who became unstable due to cardiac manipulation were excluded from off-pump beating-heart CABG.
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Figure 1. Cases of off-pump and on-pump coronary artery bypass grafting during the 24-month study period.
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All patients received standard anesthesia and routine vascular access lines. Swan-Ganz catheter monitoring was used in those with ejection fractions < 20%. Specific strategies to prevent heat loss were an integral part of the operating technique. Normothermia was ensured by keeping the surgical suite relatively warm, using a warming blanket on the operating table, warming intravenous fluids, and actively heating and humidifying respiratory gases. Pharmacologically induced bradycardia was not needed as the Octopus device provides adequate target-vessel stabilization.2 General anesthesia was maintained with a balanced technique using short-acting volatile agents supplemented with short-acting narcotics. Hypnotics were used to provide rapid weaning and extubation. Continuous low-dose propofol infusion supplemented the anesthesia while providing excellent amnesia and early arousal for extubation. Intervenous fluids were administered conservatively to prevent hemodilution. Muscle relaxants were not reversed.
The IMA was harvested by a semi-skeletonizing technique, from the upper border of the first rib to its terminal division into the musculophrenic and superior epigastric segments, using titanium clips. The IMA was harvested extrapleurally, but if the pleura was opened accidentally, a transpleural method was employed. A lateral pericardectomy was made at the level of the left atrial appendage or its corresponding location on the right side, down to the phrenic nerve. This maneuver increases the usable length of the artery as it allows the IMA to drop into a groove, and because the IMA now lies medial and posterior to the lung, ventilation does not produce any notable stretch or distortion of the vessel. The artery was palpated to confirm the presence of a strong pulse, it was left intact and wrapped in a papaverine-soaked sponge (60 mg papaverine in 30 mL saline). Allen’s test and pulse oximetry were used to assess radial and ulnar artery collateralization. A skin incision was made just medial to the brachioradialis muscle bulk and extended down towards the radial styloid process, depending on the length of graft needed. The radial artery and its 2 satellite veins were harvested by clipping the lateral branches. At no time was the radial artery held directly. Heparin (2mg•kg-1) was given to maintain the activated clotting time between 200 and 300 seconds (twice normal). The distal end of the IMA and both ends of the radial artery were transected. Pulsatile flow in the IMA was assessed grossly, and if it was insufficient due to vasospasm, papaverine diluted with blood was injected via a 1-mm cannula (Medtronic DLP, Grand Rapids, MI, USA), taking care not to overdistend the artery. The fascia along the whole length of the radial artery was cut, and both ends of the artery were tailored for grafting. To construct a Y-graft, a bulldog clamp was applied to the IMA and a longitudinal arteriotomy was made distal to the clamp. The level of the arteriotomy depended on the shortest distance to the coronary vessels to be grafted.
Anastomoses were made with continuous 8/0 monofilament suture (Ethicon, Somerville, NJ, USA). The edges of the pedicles were sutured together to prevent twisting at the anastomotic site. The proximal bulldog clamp was released and flow at the distal end of the radial artery and IMA was assessed. Pericardial stay sutures were used on the left side behind the left phrenic nerve and just in front of the left pulmonary vein. When traction was applied, these sutures maintained good elevation of the heart. The heart was gently raised by placing one or two sponges behind it. The sequence of grafting was LAD followed by the circumflex and right coronary artery, because LAD grafting requires minimal displacement of the heart. Diagonal, marginal, and sometimes the posterior descending arteries were sequentially anastomosed with radial artery after making a Y-graft with the LIMA. Hypotension occurred occasionally and usually stabilized after sustained elevation. In some patients, a 20° Trendelenburg position, volume, or adrenaline were used to maintain the blood pressure. The target coronary artery was ligated proximal and distal to the proposed arteriotomy site by placing single pledgetted 5/0 Prolene sutures (Ethicon, Somerville, NJ, USA) with the help of the back of a forceps. The Octopus device was used to immobilize the segment between the sutures; suction was maintained at 400 to 600 mm Hg, depending on the target vessel. Intracoronary shunts were used in all except a few cases where atheroma was present (to avoid embolization). The operative field was kept free from blood with a saline spray or a blower mister (Medtronic DLP, Grand Rapids, MI, USA). The anastomosis was completed with an 8/0 or 7/0 running Prolene suture. Hemostasis and deairing were achieved before tying the knot.
Heparin was neutralized with protamine sulfate. The sternum was closed after inserting drainage tubes. Patients were transferred to the intensive care unit on mechanical ventilator support. If there was no further significant blood loss, and if hemodynamics were stable, the patient was weaned off the ventilator and extubated. Routine postoperative investigations included blood gases, serial electrocardiograms, and plasma creatinine kinase and its MB fraction. Angiograms were performed routinely in the initial period of the study. In the later phase, angiography was carried out in patients with suspected angina and in those with no financial constraints on angiography. Patients who received a radial artery conduit were given oral diltiazem from the 1st postoperative day. All patients were contacted during follow-up to assess cardiac status.
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RESULTS
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Of the 803 patients, 71 (9%) had single-vessel disease, 204 (25%) had double-vessel disease, and 528 (66%) had triple-vessel disease. There were 2,661 grafts placed, with a mean of 3.31 grafts per patient (range, 1–6 grafts per patient). Operative details are given in Table 2. Grafts included LIMA (799), right IMA (142), and radial artery (708) and free IMA (24) as Y-grafts to the LIMA. Operative mortality was 0.5% (4/803). Two patients developed low cardiac output and died on the 1st and 2nd postoperative days. The other 2 were over 75 years old with history of chronic obstructive pulmonary disease, one had left main disease with unstable angina, neither could be weaned from ventilation, and both developed multiorgan failure. Postoperative details are shown in Table 3. Blood loss was low and few patients required blood transfusion. Reoperation in 9 patients was because of bleeding from an IMA branch. No patient displayed a postoperative neurological deficit. Three of the 13 patients with new renal failure required peritoneal dialysis. Bedside echocardiograms in the 6 patients with electrocardiographic and enzyme evidence of ischemia were normal in 4 cases, the other 2 showed hypokinetic apical segments that resolved within 7 days on medical management. Arrhythmias (mainly in patients on beta blockers preoperatively) responded to medical therapy in all but 2 who required cardioversion.
Postoperative angiography (Figure 2) showed a graft patency rate of 98.6% (639/648); 3 grafts (0.5%) were totally occluded and 6 (0.9%) had more than 50% stenosis. The LIMA-to-LAD graft patency was 99% (202/204). Radial artery spasm with good distal flow was noted in 2 patients (0.2%) whose radial arteries had been atheromatous and calcified preoperatively. Two of the grafted marginal vessels showed no flow. These vessels had less than 50% stenosis preoperatively; one had been accidentally grafted proximal to the lesion (Figure 2). Eight of the 23 patients who underwent endarterectomy had postoperative angiography; 2 grafts had low flow and 1 was occluded. In 2 cases, there was more than 50% stenosis distal to the LAD anastomosis, which had not been present preoperatively. These patients were asymptomatic and continued on medical management. Follow-up angiograms after 3 months do not show these stenoses which may have been caused during the ligation for anastomosis. All patients were followed up for 1 to 20 months. Six patients died during follow-up: 2 suffered sudden death, and 4 died from noncardiac causes. The survivors were all doing well at the last follow-up, with marked improvement in functional status.
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Figure 2. Arteriogram of the left coronary artery in left anterior oblique view, showing patent LIMA-to-LAD and LIMA-to-radial artery Y-grafts. Radial artery was sequentially anastomosed to the 1st and 2nd obtuse marginal branches. The graft on the 1st obtuse marginal was accidentally placed proximal to the lesion. LAD = left anterior descending coronary artery, LIMA = left internal mammary artery.
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DISCUSSION
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The ultimate achievement in CABG is for all patients to survive with freedom from coronary events, angina, and reoperation for as long as possible. Total arterial revascularization aims to overcome the late failure rate of saphenous vein grafts due to development of disease within the conduit.4 Until recently, bilateral IMA use was infrequent despite excellent results.8 Redeployment of the radial artery for bypass grafting 20 years after it had been discarded revealed good early results.9 Radial artery has many inherent advantages as a conduit for CABG: a wide and thick lumen, good length, and low injury rate during harvesting. Recent studies have demonstrated superior patency of free arterial grafts anastomosed proximally to pedicled in-situ arterial grafts, rather than directly to the aorta.10 Current CABG methods are based on techniques that evolved from beating-heart operations before the development of CPB. Encouraging reports of minimally invasive direct coronary artery bypass since the early 1990s have established off-pump CABG as a popular alternative technique of myocardial revascularization.11,12 However, there has been concern regarding the safety and efficacy of the procedure compared to the excellent results obtained with CPB, particularly because of a lack of angiographic follow-up.13 The LIMA has the highest patency rate of all bypass conduits, and an increase in the diameter of the IMA graft in response to flow demand has been observed.7 In this series, graft patency rates were comparable to those reported previously.11,12 Myocardial ischemia and coronary artery injury due to traction on proximal and distal occluding sutures are a major concern in beating-heart CABG. Intracoronary shunts were used in all except a few cases where the coronary arteries were atheromatous; the back of a forceps was used to occlude the artery during the arteriotomy. Performing CABG on a beating heart carries the risk of suboptimal anastomosis, but with devices to immobilize the heart and the use of intracoronary shunts, this risk has been minimized, as shown in this study.11,12
Incomplete revascularization has been identified as a major cause of hospital mortality and morbidity and early recurrence of angina after beating-heart CABG.14 Our goal was complete revascularization, as indicated by the high number of grafts per patient. Hypoperfusion syndrome was neither seen nor expected because the construction of composite grafts increases flow through LIMA grafts. The mortality rate of 0.5% compares well with reported rates between 0% and 3.7% for T- or Y-graft techniques.6,15 Sternal wound infection is a concern in bilateral IMA grafting, with reported incidences of up to 7%.6 Kouchoukos and colleagues16 found bilateral IMA harvesting to be the strongest predictor of a sternal complication. To reduce this problem, we used the left radial artery to make a Y-graft with the LIMA.
The low perioperative incidence of myocardial infarction confirmed the recent report by Bouchard and Cartier17 that despite cardiac elevation, hypotensive episodes, and a bluish color from venous congestion of the myocardium, a beating-heart operation can provide adequate myocardial protection compared to cardioplegic arrest. Intraoperative and postoperative blood requirements were low in this study, as noted by Arom and colleagues.18 These results are undoubtedly related to the avoidance of CPB and less use of heparin. The absence of cerebrovascular stroke and neuropsychiatric abnormalities is one of the greatest advantages of beating-heart CABG.18 It also avoids using the aorta as the site of proximal anastomosis. Despite risk factors such as diabetes mellitus, generalized atherosclerosis, and previous stroke, no major cerebrovascular event was observed in this series. Maintaining pulsatile blood flow in the off-pump procedure preserves normal homeostatic vascular function. This is manifested in the appearance and alertness of patients in the immediate postoperative period; cognitive testing was not performed in this study. However, Taggart and colleagues19 showed a pattern of early decline and late recovery of cognitive function in patients undergoing CABG with and without CPB. We observed a low incidence of renal failure, in agreement with the findings of Ascione and colleagues20 that off-pump CABG offers superior renal protection compared to revascularization on CPB. It was concluded that total arterial CABG on the beating heart is a reproducible, effective, and safe option in almost all patients, with results comparable to the conventional technique. Nevertheless, the importance of CPB should not be forgotten.
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REFERENCES
|
|---|
- Matata BM, Sosnowski AW, Galinanes M. Off-pump bypass graft operation significantly reduces oxidative stress and inflammation. Ann Thorac Surg
2000;69:785–91.[Abstract/Free Full Text]
- Spooner TH, Dyrud PE, Monson BK, Dixon GE, Robinson LD. Coronary artery bypass on the beating heart with the Octopus: a North American experience. Ann Thorac Surg
1998;66:1032–5.[Abstract/Free Full Text]
- Borst C, Jansen EW, Tulleken CA, Grundeman PF, Mansvelt Beck HJ, van Dongen JW, et al. Coronary artery bypass grafting without cardiopulmonary bypass and without interruption of native coronary flow using a novel anastomosis site restraining device ("Octopus"). J Am Coll Cardiol
1996;27:1356–64.[Abstract]
- Zeff R, Kongtahworn C, Iannone L, Gordon D, Brown T, Philips S, et al. Internal mammary artery versus saphenous vein graft to the left anterior descending coronary artery: prospective randomized study with 10-year follow-up. Ann Thorac Surg
1988;45:533–6.[Abstract]
- Royse A, Royse C, Raman J. Exclusive Y graft operation for multivessel coronary revascularization. Ann Thorac Surg
1999;68:1613–9.
- Tector AJ, Amundsen S, Schmahl TM, Kress DC, Peter M. Total revascularization with T graft. Ann Thorac Surg
1994;57:33–9.[Abstract]
- Tector AJ, Schmahl TM, Canino VR. Expanding the use of the internal mammary artery to improve patency in coronary artery bypass grafting. J Thorac Cardiovasc Surg
1986;91:9–16.[Abstract]
- Pick A, Orszulak T, Anderson B, Schaff H. Single versus bilateral internal mammary artery grafts: 10-year outcome analysis. Ann Thorac Surg
1997;64:599–605.[Abstract/Free Full Text]
- Acar C, Jebara VA, Portoghese M, Beyssen B, Pagny JY, Grare P, et al. Revival of the radial artery for coronary artery bypass grafting. Ann Thorac Surg
1992;54:652–60.[Abstract]
- Calafiore AM, Di Giammarco G, Luciani N, Maddestra N, Di Nardo E, Angelini R. Composite arterial conduits for a wider arterial myocardial revascularization. Ann Thorac Surg
1994;58:185–90.[Abstract]
- Calafiore AM, Teodori G, Di Giammarco G, Vitolla G, Iaco A, Iovino T, et al. Minimally invasive coronary artery bypass grafting on a beating heart. Ann Thorac Surg
1997;63:S72–5.
- Subramanian VA, McCabe JC, Geller CM. Minimally invasive direct coronary artery bypass grafting: two-year clinical experience. Ann Thorac Surg
1997;64:1648–55.[Abstract/Free Full Text]
- Lytle BW. Minimally invasive cardiac surgery. J Thorac Cardiovasc Surg
1996;111:554–5.
- Jones EL, Weintraub WS. The importance of completeness of revascularization during long-term follow-up after coronary artery operations. J Thorac Cardiovasc Surg
1996;112:227–37.[Abstract/Free Full Text]
- Nicholson IA, Paterson HS. Modified T graft for triple-vessel disease. Ann Thorac Surg
1997;64:451–3.[Abstract/Free Full Text]
- Kouchoukos NT, Wareing TH, Murphy SF, Pelate C, Marshall WG Jr. Risk of bilateral internal mammary artery bypass grafting. Ann Thorac Surg
1990;49:210–9.[Abstract]
- Bouchard D, Cartier R. Off-pump revascularization of multivessel coronary artery disease has a decreased myocardial infarction rate. Eur J Cardio-thorac Surg
1998;14(Suppl 1):20–4.
- Arom KV, Flavin TF, Emery RW, Kshettry VR, Janey PA, Petersen RJ. Safety and efficacy of off-pump coronary artery bypass grafting. Ann Thorac Surg
2000;69:704–10.[Abstract/Free Full Text]
- Taggart DP, Browne SM, Halligan PW, Wade DT. Is cardiopulmonary bypass still the cause of cognitive dysfunction after cardiac operation? J Thorac Cardiovasc Surg
1999;118:414–21.[Abstract/Free Full Text]
- Ascione R, Lloyd CT, Underwood MJ, Gomes WJ, Angelini GD. On-pump versus off-pump coronary revascularization: evaluation of renal function. Ann Thorac Surg
1999;68:493–8.[Abstract/Free Full Text]
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ABSTRACT
INTRODUCTION
