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Ann Thorac Surg 1996;62:924-931
© 1996 The Society of Thoracic Surgeons
Oxford Heart Center, Oxford Radcliffe Hospital, Oxford, England
Accepted for publication May 20, 1996.
In March 1996, a capacity audience of 450 delegates met in Oxford for the First International Live Teleconference on Less Invasive Coronary Bypass Surgery. The aim of the meeting was to discuss the scope and current status of this new approach. The program included six live surgical procedures with active discussion between the auditorium and the operating room.
Background
In the late 1950s before cardiopulmonary bypass came into widespread use, coronary endarterectomy or segmental excision with saphenous vein or internal mammary artery grafts was performed on the beating heart [1–3]. Longmire recalls the first direct anastomosis between the left internal mammary artery (LIMA) and the left anterior descending coronary (LAD) in 1958: "At the time we were doing the coronary thrombo-endarterectomy procedure and we also performed a couple of the earliest internal mammary to coronary anastomoses. We were forced into it when the coronary artery we were endarterectomising disintegrated and, in desperation, we anastomosed the LIMA to the distal end of the right coronary artery and later decided it was a good operation." Sabiston performed a right coronary artery saphenous vein graft in 1962 and DeBakey succeeded with a vein bypass of the left coronary artery without cardiopulmonary bypass in 1964 [3]. This event was published only after 7-year angiographic follow-up showed that the graft was patent. From 1968 onward widespread adoption of cardiopulmonary bypass and cardioplegia greatly facilitated the coronary operation and provided the stimulus for a dramatic increase in the number and complexity of the procedure [4]. This stifled further efforts to operate on the beating heart at a time when vascular surgical techniques were relatively primitive.
Coronary bypass operations are undertaken without opening a cardiac chamber, and consequently it is not necessary to divert blood from within the heart. With continued ventilation of the lungs and unimpaired pulmonary blood flow, there is no need for an oxygenator. The only technical requirement for coronary bypass is a bloodless anastomotic field. This can be achieved by temporary coronary occlusion while the circulation is supported through uninterrupted cardiac action. Besides the historical documentation of this approach, we are progressively aware, from percutaneous transluminal angioplasty experience, that coronary occlusion and myocardial ischemia are well tolerated for up to 15 to 20 minutes, particularly after a short period of ischemic preconditioning [5]. This is longer than the time needed to isolate a coronary artery, open the vessel, and apply either an internal mammary artery or saphenous vein graft.
Motivation for Change
The current drive toward cost containment is changing clinical practice with the emphasis on less invasive procedures and simplicity. Although clinical trials of percutaneous transluminal coronary angioplasty versus operation show coronary artery grafting to be clearly superior, the patients' wish to avoid an operation, together with excessive surgical waiting times in some countries and the lesser, immediate expense, have promoted diversification of percutaneous transluminal coronary angioplasty to those with multivessel disease [6–8]. Percutaneous transluminal coronary angioplasty has usurped practically all of the straightforward one- and two-vessel interventions. However, given the facts, informed consent based on the randomized trials should lead more patients with a combination of left anterior descending and right coronary artery occlusion to opt for bypass grafting. The fact that percutaneous transluminal coronary angioplasty of the alleged culprit lesion (often with sacrifice of diagonal or marginal branches) gained acceptance in the medical community is an argument in support of less invasive nonbypass procedures.
Conventional coronary operations with cardiopulmonary bypass are both safe and effective. The pump oxygenator provides continuous systemic circulation, while cardioplegic arrest ensures myocardial protection and an accurate anastomosis in a still operative field. The method lends itself to complete myocardial revascularization with predictable long-lasting results, even in patients with severe three-vessel disease. A three- or four-graft operation can take less than 2 hours in the operating room with less than 2 hours of postoperative ventilation and a 5-day postoperative stay. With minimal surgical morbidity and mortality, why change this practice?
The aims of less invasive coronary surgery are to reduce perioperative morbidity further and promote earlier hospital discharge. In turn the effectiveness of the coronary operation and the long-term outcome must be preserved. In thoracic, abdominal, and pelvic surgery, less invasive techniques equate with smaller incisions. It is generally agreed that postoperative morbidity in cardiac surgery stems from the damaging effects of cardiopulmonary bypass, rather than the median sternotomy [9–11]. Median sternotomy is a more comfortable incision than thoracotomy and requires less postoperative hospital time than recovery from cardiopulmonary bypass. Interaction between blood and foreign surfaces activates complement and neutrophils to produce a whole-body inflammatory response [9]. Intrapulmonary sequestration of white cells with generation of oxygen free radicals and protease enzymes causes the interstitial edema generally implicated in the need for postoperative ventilation [10]. These mechanisms, together with cerebral microembolism, also contribute to the debilitating cerebral neuropsychological consequences of cardiopulmonary bypass [12–14]. Together with the cost of bypass equipment, intensive care, and extended hospital stay, they argue in favor of coronary operations without cardiopulmonary bypass [15].
After the early nonpump coronary operations, a few surgeons persisted, largely for economic reasons. In Argentina and Brazil, Benetti and associates [16] and Buffolo and colleagues [17] independently reported large series performed by simple interruption of coronary flow. Postoperative angiographic studies showed no significant difference in graft patency between patients operated on with and without cardiopulmonary bypass, or when saphenous vein or the internal mammary artery was used. Persuasive results led to renewed interest in the United States. Pfister and associates [18] of the Washington Hospital Center reported 220 operations off bypass, comparing the outcome with 220 conventional operations matched for number of grafts, left ventricular function, and date of operation. They concluded that selected patients with disease of the left anterior descending and right coronary arteries could safely undergo coronary operations without cardiopulmonary bypass and that left ventricular function was better preserved than after cold cardioplegic arrest. Akins and colleagues [19], in a comparative study of coronary operations performed with and without extracorporeal circulation, documented superior preservation of left ventricular function, despite extended periods of unprotected regional ischemia. Postoperative septal wall motion abnormalities were found in patients operated on with cardiopulmonary bypass and cross-clamp fibrillation, whereas those operated on without either had no change or an improvement in septal motion after revascularization. Benetti and associates [20] explored this aspect further by performing intraoperative left ventricular biopsies, which showed superior preservation of the mitochondria in the nonbypass patients. Myocardial reperfusion injury has a central role in the pathophysiology of myocardial stunning but does not appear to be important in nonpump patients, despite occlusion times of 15 to 20 minutes [21]. Cardiopulmonary bypass activates leukocytes, which contribute to reperfusion injury [9]. It appears that temporary obstruction of a partially occluded vessel in a non-cardiopulmonary bypass case does not produce the same degree of injury as global ischemia followed by reperfusion with activated leukocytes.
Collectively the data from these groups suggest that nonpump coronary bypass procedures are safe, cost-effective, and advantageous, notably for those with impaired ventricles [22]. For those who wish to avoid blood transfusion, the avoidance of hemodilution virtually guarantees this [16]. For those at high risk of morbidity from cardiopulmonary bypass, for example with a calcified (eggshell) aorta or carotid occlusion, grafting of a culprit lesion in an accessible territory with one or both internal mammary arteries is preferable to the near-certainty of cerebral injury through conventional techniques. Perhaps the most compelling reason for avoiding cardiopulmonary bypass is the absence of perfusion-related cerebral injury. The ability to extubate early, together with rapid rehabilitation and early hospital discharge, are secondary considerations because rapid extubation is feasible in cardiopulmonary bypass patients [23].
The Scope of Less Invasive Coronary Operations
Surgical invasiveness depends on the severity of postoperative physiologic derangement and its effect on recovery. Viewed in this way, less invasive coronary surgery depends primarily on avoidance of the damaging effects of cardiopulmonary bypass and secondarily on access through smaller incisions. Technological advances in 1991 allowed a miniaturized video camera to be placed at the end of a thoracoscope, and percutaneous stapling devices permitted wedge resection of the lung. Initial enthusiasm for video-assisted thoracic surgery was tremendous until limited exposure and difficulty in manipulating tissues showed the method to be inappropriate for curative operations in patients with malignancy [24]. Regardless of the technique used for an operation, it is important to achieve the long-term aim of curing the patient's problem and not to overemphasize the importance of wound size or duration of hospital stay.
Median sternotomy provides unparalleled access to the left anterior descending and right coronary arteries, which can be grafted while the heart supports the circulation. This approach allows easy access to both internal mammary arteries and allows vein or radial arterial grafts to be anastomosed to the aorta with a side clamp. The coronary anastomosis can be facilitated by slowing the heart with a pharmacologic agent such as esmolol, verapamil, or adenosine [25, 26]. As surgeons gain increasing experience and familiarity with coronary anastomoses on the beating heart, the circumflex marginal branches can be approached by applying stay sutures to the posterior aspect of the pericardium and lifting this forward. There is now considerable experience with nonpump coronary operations through the sternotomy approach, and this is certainly the best starting point for the beginner. Sternotomy carries remarkably little morbidity and is perhaps the least painful surgical incision. Pain from the sternotomy will not delay discharge from the hospital after the second or third postoperative day, and partial lower sternotomy can provide sufficient access for LIMA grafting to the LAD or right internal mammary artery grafting to the right coronary artery.
There is now a drive toward minimal access coronary revascularization and a rapidly developing supportive industry. The minimal-access approach began with the LIMA graft to the LAD through a 10-cm transverse incision over the fourth costal cartilage [27]. One and sometimes two cartilages were excised to provide access to the LIMA above and below the incision. New thoracoscopic instrumentation is being developed to assist in dissection of this vessel [28]. When the pericardium is opened directly beneath the incision, the LAD is usually readily accessible, providing that this does not take an intramyocardial course. The minimally invasive direct coronary artery bypass (MIDCAB) procedure is performed by placing occlusive slings above and below the site of anastomosis and performing the suture line under direct vision. Because the chest wall incision lies directly over the LAD, the degree of cardiac motion and displacement of the heart are minimal. Patients are able to leave hospital between 48 and 72 hours postoperatively, but a proportion complain of persistent wound pain. This is caused by intercostal nerve injury through traction on the wound edges and has been addressed by not excising the costal cartilage and using single-lung anesthesia with videoscopic assistance to harvest the LIMA. Other less invasive approaches have followed. The right internal mammary artery can be mobilized through a fifth intercostal space incision and anastomosed to a proximally occluded right coronary artery. A subxiphoid approach can be used to mobilize the gastroepiploic artery and graft the posterior descending coronary artery for more distal right coronary disease [28]. This approach is particularly useful for reoperations where a LIMA or vein grafts to the left coronary branches are patent. In potentially difficult reoperations a left thoracotomy can be used to approach the circumflex coronary branches. Saphenous vein or radial arterial grafts can be used between the circumflex coronary and the ascending or descending thoracic aorta. Combinations of the so-called less invasive approaches can be used for multiple grafts, but it is difficult to see how these time-consuming incisions are an improvement over median sternotomy.
New Technology in Less Invasive Coronary Bypass
As with video-assisted thoracic surgery, new instrumentation is evolving to facilitate coronary anastomoses on the beating heart. The aim of cardiac support using miniature axial-flow pumps instead of cardiopulmonary bypass is to permit ventricular motion to be markedly slowed pharmacologically, while retaining coronary, systemic, and pulmonary blood flow even if the heart fibrillates. Two devices currently address this requirement; the Hemopump recently acquired by Medtronic (Minneapolis, MN) and the Jarvik Cannula Pump (Jarvik Research, NY) [29].
The transthoracic Hemopump is a catheter-mounted axial-flow pump introduced into the left ventricular cavity retrogradely via the ascending aorta and aortic valve (Fig 1
). The cannula length is 8.5 cm, and the maximum diameter is 8.1 mm (24F). A 12-mm Dacron graft is sutured onto the ascending aorta to facilitate introduction. The position of the cannula in the ventricle is confirmed by direct palpation of the ascending aorta. The occluding plugs around the drive cable are tied to prevent blood loss through the graft and to secure the cannula in its position. With a maximum speed of 26,000 revolutions per minute and a pressure difference of 70 mm Hg, the Hemopump produces a nonpulsatile flow of up to 4.8 L/min. There is already experience with this device for postcardiotomy support (instead of the intraaortic balloon pump) and for bypass grafts to the LAD and right coronary arteries. Attempts to graft the circumflex coronary have been unsuccessful due to displacement of the pump.
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) [30]. This drives the axial-flow pump impeller via a short shaft, which is supported on blood-immersed bearings. The device is inserted into the apex of the left ventricle, and a second device can be used within the right ventricle to completely unload the myocardium. A flexible, polymeric, wire-reinforced outflow cannula extends across the aortic valve, and inlet holes, similar to the slots of a suction tip catheter, permit the blood to enter the pump directly from the ventricular chamber while preventing myocardial tissue from occluding the openings. Insertion of the cannula across the aortic valve is relatively simple. The electric cable, which crosses the apex, is only a few millimeters in diameter and is highly flexible. The 10-mm-diameter cannula pump operates at an overall efficiency of 10% to 15%, which requires only 6 to 10 W of input power to produce flow at 5 L/min and 80 mm Hg pressure. This pump has the ability to completely capture the cardiac output so that at 15,000 revolutions per minute the aortic wave form becomes almost nonpulsatile at the systolic level, whereas left atrial pressure remains in the optimal range between 0 and 5 mm Hg. Left ventricular pressure averages 0 mm Hg, and right heart function is not altered. Neither the Hemopump nor the Jarvik Cannula Pump causes significant hemolysis.
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One of the principal difficulties in less invasive coronary surgery is accuracy of the coronary anastomosis on a beating heart with limited access. If this particular problem cannot be solved then graft patency will be disappointing and the method will fall into disrepute. Anastomosis between a small LIMA/right internal mammary artery or gastroepiploic arteries and a severely diseased coronary artery in constant motion is a technical challenge. Even with cardioplegic arrest, these anastomoses can be taxing. Consequently, new instruments have been designed to eliminate movement at the anastomotic site. One of these instruments from Cardiothoracic Systems (CA) is placed like a parallel pair of skis on either side of the artery and with light pressure on the myocardium greatly decreases cardiac motion at site of application (Fig 3). This instrument can be hand held or attached to a new retractor designed to improve access for internal mammary artery dissection with the anterior thoracotomy approach. This retractor elevates the second and third ribs and depresses the first and second ribs to improve visualization of the mammary pedicle (Fig 4). This type of instrument can be used in conjunction with new videoscopic equipment based on fighter pilot headgear from the Vista Medical Company (CA). The videoscopic image is transmitted directly into the surgeon's headset, which can also display pictures of the angiogram or other investigations while also allowing the surgeon direct vision of the operative site (Fig 5). Thoracoscopic mobilization of the LIMA or right internal mammary artery can be combined with direct access or via a separate videoscopic entry point (Fig 6).
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Six live operations were transmitted from the operating room to the auditorium. The quality of the camera work was such that the audience had either the same or a better view than the surgeon wearing magnifying glasses. The first operation was performed through a median sternotomy with an LIMA graft to the left anterior descending coronary artery and vein grafts to the principal diagonal and circumflex marginal branch of the left coronary artery. The operation was performed on the beating heart with circumferential stay sutures to steady the operative field. A gas jet was used to maintain a bloodless anastomotic field. Stay sutures in the posterior aspect of the pericardium elevated the heart to improve access to the circumflex marginal branch. The operation was performed uneventfully in less than 2 hours, and the patient appeared in the auditorium fit and well the following day.
The second patient required grafts to the LAD and posterior descending branch of the right coronary artery. This operation was performed through a median sternotomy, using the Hemopump to decompress the left ventricle and sustain the circulation while the heart was slowed with esmolol. The Hemopump was inserted through a vascular graft anastomosed to the ascending aorta using a side clamp and passed retrogradely through the aortic valve. The LIMA was used to graft the LAD, and saphenous vein was anastomosed to the posterior descending branch of the right coronary artery. The procedure was uneventful, and the combination of left ventricular decompression and esmolol to provide a heart rate of 40 beats/min facilitated the anastomoses. Again, the operation took less than 2 hours and the patient recovered rapidly.
The next four operations were performed with a minimal access approach. For three patients this involved a fourth left intercostal space incision with mobilization of the LIMA. For the third of these patients it was also intended to perform a right fifth inter-space incision, to graft the right coronary artery. The last patient in the less invasive group was undergoing a reoperation in the presence of a patent LIMA graft to the LAD and a circumflex vein graft. The intention was to perform a gastroepiploic graft to the posterior descending artery.
On this occasion access in the MIDCAB thoracotomy patients was limited to the intercostal space without removing the costal cartilage. Visualization of the LIMA was improved by the purpose-built retractor, but in the first patient there was difficulty in mobilizing a sufficient length of LIMA. This aspect of the operation took almost 2 hours, but eventually length was achieved by dissecting the LIMA from the first intercostal space to the sixth interspace. The pericardium was then opened and the anastomosis performed with the aid of stay sutures and the stabilizing device attached to the retractor. The procedure was concluded satisfactorily.
The next 76-year-old patient had severe emphysema. At the end of a protracted LIMA dissection the vessel would not reach the LAD, and the patient underwent median sternotomy for a vein graft (performed uneventfully without cardiopulmonary bypass). The third MIDCAB procedure was difficult. An anastomosis between the LIMA and the LAD was performed but was compromised by calcification in the vessel. This patient underwent median sternotomy with a revised LIMA graft to the LAD and a vein graft to the right coronary artery. Thoracoscopic mobilization of the LIMA from a separate, more lateral access port helps to avoid these problems. The same operators have previously published a collective series of 30 patients from three centers where the operations were completed without morbidity or mortality and with angiographic proof of graft patency.
The last patient was approached through a midline epigastric incision, with excision of the xiphisternum. The peritoneum was opened to harvest the gastroepiploic artery, and then the lower end of the sternum was elevated to expose the diaphragmatic aspect of the pericardium. Access to the inferior aspect of the heart was made easier by intrapericardial adhesions from the first operation. The right coronary artery was easily identified and mobilized between silicone slings, which elevated the vessel away from the myocardium. The anastomosis between the epigastric artery and the posterior descending branch was performed uneventfully, and the patient made a straightforward recovery.
During the course of each operation, left ventricular function was monitored by continuous transesophageal echocardiography and myocardial ischemia by the electrocardiogram. When completely occluded vessels were grafted, there was no significant alteration of left ventricular wall motion and little change in the electrocardiogram. Segmental wall motion abnormalities were only seen when vessels with less than 75% occlusion were obstructed. For the MIDCAB patients the duration of occlusion exceeded 20 minutes, during which segmental wall motion abnormalities occurred, in conjunction with ST segment elevation. These changes resolved after the coronary snares were removed. Segmental wall motion disturbance and esmolol infusion caused a certain amount of hemodynamic instability, which was managed pharmacologically. The role of ischemic preconditioning, performed by a 5-minute preliminary coronary occlusion followed by reperfusion before reocclusion for the anastomosis, remains to be defined.
Although the unsettling environment of a live teleconference does not necessarily reflect routine clinical practice, the difficulties encountered by experienced protagonists provided an important note of caution. It will be some time before the MIDCAB approach can be regarded as easily reproducible and as effective as a conventional operation. There is a learning curve, which may prove steeper than anticipated. "Off-pump" anastomoses via median sternotomy should perhaps be the first part of this learning curve.
Some of the delegates profoundly criticized the quality of the coronary anastomoses during the minimal access procedures. The cameras provided a greatly magnified image, and it was generally considered that the anastomosis looked less satisfactory than that obtained with cardioplegic arrest. Consequently, it was generally agreed that angiographic confirmation of graft patency would be required when publishing the results of minimally invasive procedures. Other methods cannot be relied upon to reflect graft patency months after the operation because of the propensity of collateral circulation to develop, which prevents symptoms in patients with single-vessel occlusion. At the end of the meeting the delegates were split between the evangelists, enthusiasts, and sceptics, with a predominance of the latter. A number of conclusions were drawn:
Acknowledgments
The program directors thank the faculty and surgeons who operated in a foreign environment with some new and unfamiliar instruments. These included Dr O. H. Frazier, Dr James D. Fonger, Dr Valavanur Subramanian, Dr Hani Shennib, Dr G. Sani, Dr Píerre A. Grandjean, Dr Piet Boonstra, and Mr David Taggart. The meeting was organized by ProMedica International and supported by Cardiothoracic Systems and the Vista Medical Corporation.
Footnotes
Address reprint requests to Dr Westaby, Department of Cardiac Surgery, Oxford Heart Center, Oxford Radcliffe Hospital, The John Radcliffe, Headington, Oxford OX3 9DU, England.
References
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|
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|
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|
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 R Ascione and G.D Angelini OPCAB surgery: a voyage of discovery back to the future Eur. Heart J., January 2, 2003; 24(2): 121 - 124. [Full Text] [PDF]
|
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|
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|
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|
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|
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|
|
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|
|
|
|
 |
|
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|
|
|
|
|
|
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|
|
|
|
|
|
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|
|
|
|
 |
|
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|
|
|
|
|
|
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|
|
|
|
|
|
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|
|
|
|
|
|
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|
|
|
|
 |
|
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|
|
|
|
|
|
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|
|
|
|
|
|
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|
|
|
|
 |
|
 R. DuBroff, S. Walji, L. I. Bonchek, and D. J. Ullyot Minimally Invasive Heart Surgery • Response Circulation, June 8, 1999; 99 (22): 2967 - 2967. [Full Text] [PDF]
|
|
|
|
|
|
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|
|
|
|
|
|
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|
|
|
|
|
|
H. J. Penttila, M. V.K. Lepojarvi, P. K. Kaukoranta, K. T. Kiviluoma, K. V. Ylitalo, and K. J. Peuhkurinen Myocardial metabolism and hemodynamics during coronary surgery without cardiopulmonary bypass Ann. Thorac. Surg., March 1, 1999; 67(3): 683 - 688. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
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|
|
|
|
|
|
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|
|
|
|
|
|
B. L. Bufkin, J. D. Puskas, J. Vinten-Johansen, S. T. Shearer, and R. A. Guyton Controlled intermittent asystole: pharmacologic potentiation of vagal-induced asystole Ann. Thorac. Surg., October 1, 1998; 66(4): 1185 - 1190. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
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|
|
|
|
|
|
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|
|
|
|
|
|
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|
|
|
|
|
|
M. Massetti, G. Babatasi, A. Lotti, S. Bhoyroo, O. Le Page, and A. Khayat Less invasive cardiac operations through a median sternotomy: 100 consecutive cases Ann. Thorac. Surg., September 1, 1998; 66(3): 1050 - 1054. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Y. Karagoz, M. Kurtoglu, G. Ozerdem, B. Battaloglu, S. Korkmaz, and K. Bayazit Minimally invasive coronary artery bypass grafting: The rib cage-lifting technique J. Thorac. Cardiovasc. Surg., August 1, 1998; 116(2): 354 - 356. [Full Text] [PDF]
|
|
|
|
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G. Watanabe, T. Misaki, K. Kotoh, A. Yamashita, and K. Ueyama Bilateral Thoracoscopic Minimally Invasive Direct Coronary Artery Bypass Grafting Using Internal Thoracic Arteries Ann. Thorac. Surg., June 1, 1998; 65(6): 1673 - 1675. [Abstract] [Full Text] [PDF]
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 B Bridgewater, R S Steyn, S Ray, and T Hooper Minimally invasive aortic valve replacement through a transverse sternotomy: a word of caution Heart, June 1, 1998; 79(6): 605 - 607. [Abstract] [Full Text]
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A. M. Calafiore, G. D. Giammarco, G. Teodori, S. Gallina, N. Maddestra, L. Paloscia, G. Scipioni, T. Iovino, M. Contini, and G. Vitolla Midterm results after minimally invasive coronary surgery (last operation) J. Thorac. Cardiovasc. Surg., April 1, 1998; 115(4): 763 - 771. [Abstract] [Full Text] [PDF]
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V. R. Machiraju, M. H. Culig, R. L. Heppner, R. A. Minella, and J. D. O'Toole Value of Reversed Saphenous Vein in Minimally Invasive Direct Coronary Artery Bypass Graft Procedures Ann. Thorac. Surg., March 1, 1998; 65(3): 625 - 627. [Abstract] [Full Text] [PDF]
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R. R. Lazzara, B. A. McLellan, F. E. Kidwell, D. T. Combs, J. T. Hanlon, and E. K. Young Intraoperative Angiography During Minimally Invasive Direct Coronary Artery Bypass Operations Ann. Thorac. Surg., December 1, 1997; 64(6): 1725 - 1727. [Abstract] [Full Text]
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M. Takahashi, S. Yamamoto, and S. Tabata IMMOBILIZED INSTRUMENT FOR MINIMALLY INVASIVE DIRECT CORONARY ARTERY BYPASS: MIDCAB DOUGHNUT J. Thorac. Cardiovasc. Surg., October 1, 1997; 114(4): 680 - 682. [Full Text]
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I. S. Gill, G. M. FitzGibbon, L. A. J. Higginson, A. Valji, and W. J. Keon Minimally Invasive Coronary Artery Bypass: A Series With Early Qualitative Angiographic Follow-up Ann. Thorac. Surg., September 1, 1997; 64(3): 710 - 714. [Abstract] [Full Text]
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I. Birdi, M Caputo, J. A. Hutter, A. J. Bryan, and G. D. Angelini TROPONIN I RELEASE DURING MINIMALLY INVASIVE CORONARY ARTERY SURGERY J. Thorac. Cardiovasc. Surg., September 1, 1997; 114(3): 509 - 510. [Full Text]
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R. A. Ott, D. E. Gutfinger, M. P. Miller, A. Selvan, M. A. Codini, H. Alimadadian, and T. M. Tanner Coronary Artery Bypass Grafting "On Pump": Role of Three-Day Discharge Ann. Thorac. Surg., August 1, 1997; 64(2): 478 - 481. [Abstract] [Full Text]
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G. Watanabe, T. Misaki, K. Kotoh, Y. Abe, A. Yamashita, and K. Ueyama BILATERAL MINIMALLY INVASIVE DIRECT CORONARY ARTERY BYPASS GRAFTING WITH THE USE OF TWO ARTERIAL GRAFTS J. Thorac. Cardiovasc. Surg., May 1, 1997; 113(5): 949 - 951. [Full Text]
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L. P. Perrault, P. Menasche, J.-P. Bidouard, C. Jacquemin, N. Villeneuve, J.-P. Vilaine, and P. M. Vanhoutte Snaring of the Target Vessel in Less Invasive Bypass Operations Does Not Cause Endothelial Dysfunction Ann. Thorac. Surg., March 1, 1997; 63(3): 751 - 755. [Abstract] [Full Text]
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