Clinical Results With Left Axillary to Left Anterior Descending Coronary Artery Bypass James A. Magovern, MD, Timothy J. Hunter, MD, and Pyongsoo D. Yoon, MD Department of Cardiothoracic Surgery, Allegheny General Hospital, Pittsburgh, Pennsylvania, and Northside Medical Center/Forum Health, Youngstown, Ohio
Background. The minimally invasive direct coronary artery bypass procedure is not feasible if the left internal mammary artery has been used or has inadequate flow. We have applied a modified minimally invasive direct coronary artery bypass procedure, which uses a graft from the left axillary artery to the left anterior descending coronary artery in such situations. Methods. The graft is anastomosed to the left axillary artery adjacent to the clavicle and tunneled underneath the vein, where it enters the thorax through the first interspace and courses to the left anterior descending coronary artery along the mediastinum. Results. Since 1997 we have used this operation in 22 patients with a mean age of 70 years (range, 52 to 83 years). All patients were high-risk candidates because of advanced age (70 ⴞ 7 years), depressed left ventricular function (mean left ventricular ejection fraction, 38% ⴞ 6%), or previous heart operation (20 of 22, 91%). Conduits
for the graft were saphenous vein (n ⴝ 18) or radial artery (n ⴝ 4). Ten patients were extubated in the operating room, and the mean duration of mechanical ventilation was 5.8 ⴞ 6 hours. There was one operative death (1 of 22, 4.5%). The mean length of intensive care unit and hospital stay was 1.5 days (range, 1 to 6 days) and 6 days (range, 2 to 15 days), respectively. At a mean follow-up of 6 months, all discharged patients are alive and functionally improved. None have required surgical or catheter-based revascularization of the left anterior descending coronary artery. Conclusions. The left axillary artery to left anterior descending coronary artery graft should be considered for high-risk patients in whom a minimally invasive direct coronary artery bypass procedure is not possible.
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Material and Methods
inimally invasive direct coronary artery bypass (MIDCAB) is an effective technique for revascularization of the left anterior descending coronary artery (LAD) [1]. The procedure can be performed with minimal morbidity, low cost, and excellent graft patency [2, 3]. The MIDCAB operation is especially useful for high-risk patients [4]. A particularly difficult group of patients are those who need a redo coronary artery bypass graft (CABG) operation when the left internal mammary artery to LAD graft is occluded and the other grafts are still patent. These patients need a minimally invasive technique, but they are not candidates for MIDCAB because the left internal mammary artery has been used. For this group of patients we have applied a technique that mimics the MIDCAB procedure, by using the proximal axillary artery for inflow to a graft anastomosed to the LAD by means of an anterior thoracotomy. We have termed this procedure the left axillary artery (LAX) to LAD operation. This report summarizes our experience with this procedure during a 3-year period.
(Ann Thorac Surg 2001;71:561– 4) © 2001 by The Society of Thoracic Surgeons
Patient Population A total of 22 patients were operated on during a 3-year period at two institutions (Allegheny General Hospital and Northside Medical Center) from a total of approximately 4,000 patients undergoing CABG at these institutions during the study period. The mean age was 70 ⫾ 7 years, and the sex distribution was 10 men and 12 women. Ninety-one percent of the patients (20 of 22) had previous CABG. Two patients (2 of 22, 9%) were first-time operations in high-risk patients. One patient had endstage emphysema, and the other had a recent stroke and unstable angina. All of the patients were considered to be high-risk candidates for traditional operation owing to advanced age, depressed cardiac function, associated comorbid diseases, or previous operations (Table 1). Saphenous vein was used in 18 of 22 patients, but it was necessary to use the left radial artery in 4 patients (4 of 22, 18%) because they were having a third CABG operation and the saphenous vein was not available.
Surgical Technique Accepted for publication Sept 25, 2000. Address reprint requests to Dr Magovern, Department of Cardiothoracic Surgery, Allegheny General Hospital, 320 E North Ave, Pittsburgh, PA 15212; e-mail:
[email protected].
© 2001 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
A double-lumen endotracheal tube was used to allow collapse of the left lung. An anterior thoracotomy incision was made, starting adjacent to the sternum and extending past and above the left nipple. The chest was entered through the fourth intercostal space. Adhesions were 0003-4975/01/$20.00 PII S0003-4975(00)02460-7
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Table 1. Preoperative Risk Factors Factor Ejection fraction ⬍ 40% Age ⬎ 70 years Redo operation Third-time operation Current smoking Peripheral vascular disease Diabetes mellitus
Number (%) 12 (55) 10 (45) 20 (91) 4 (18) 13 (59) 6 (27) 10 (45)
divided between the lung and the mediastinum, and between the lung and the heart. The LAD was identified and inspected, which was facilitated by the presence of a previous graft to the vessel. Once it was clear that the LAD was graftable, then the axillary artery was exposed by means of an incision just below and parallel to the middle part of the clavicle. The axillary artery and vein were encircled as they exit from beneath the clavicle. An incision that admits two fingers was made in the medial aspect of the first interspace. Ten thousand units of heparin was given and the artery was clamped. A 4-mm punch was used to prepare a site on the axillary artery for the proximal anastomosis. The graft was anastomosed with a 6-0 polypropylene suture, tunneled beneath the axillary vein, and placed in the thoracic cavity. The graft was then retrieved from the apex of
the chest through the thoracotomy incision, taking care not to twist or kink the graft. The distal anastomosis was made using 7-0 polypropylene and with the assistance of a mechanical stabilizer, a shunt, and a carbon dioxide blower. Graft flow was confirmed with a micro-Doppler device (Fig 1).
Follow-up All operative survivors were seen in the office at 6 weeks after operation and were contacted by telephone 6 months later. Patients were specifically questioned about the need for cardiac catheterization, interventional cardiology procedure, and operation.
Results Operative Morbidity and Mortality There was 1 operative death (1 of 22, 4.5%). This patient was an 81-year-old man with severely depressed left ventricular function and previous coronary operation who died of respiratory failure. The mean 24-hour blood loss was 622 ⫾ 560 mL, and 36% (8 of 22) received packed red blood cell transfusion. No patients required platelets or fresh-frozen plasma. Slightly less than half of the patients (10 of 22, 46%) were extubated in the operating room. The mean time for postoperative mechanical ventilation was 5.8 ⫾ 6 hours, and all were extubated within 24 hours. Mean intensive care length of stay was 1.5 days (range, 1 to 6 days), and mean postoperative length of stay was 6 days (range, 2 to 15 days), excluding 1 patient who stayed 22 days. Reexploration for bleeding, stroke, renal failure, or wound infection did not occur.
Late Follow-up All patients were seen at 6 to 8 weeks after operation for an office visit. Long-term survival and the need for repeat revascularization procedures were evaluated by telephone contact or an office visit. In a 6-month time frame all patients were alive and none required additional surgical revascularization or interventional procedures. The first patient had coronary angiography at 6 months after operation because of atypical chest pain. The graft was widely patent and is shown in Figure 2.
Comment
Fig 1. Doppler flow velocity in left axillary artery to left anterior descending coronary artery grafts. (Top) Saphenous vein graft. (Bottom) Radial artery graft. Both show flow throughout diastole, indicating a patent graft.
Our clinical experience with the LAX to LAD graft shows that this procedure shares many of the benefits of the MIDCAB operation. The technical aspects are straightforward, the blood loss is minimal, and the morbidity is very low, even in high-risk patients. In this series, 91% of the patients were redo procedures, and 18% (4 of 22) were third-time surgical revascularization operations. In addition, the mean age was 70 years, and many of the patients had depressed left ventricular function. Despite these multiple adverse risk factors, the early morbidity and mortality were low. Late follow-up demonstrates excellent relief of symptoms and no need for reintervention. Others have reported using the axillary artery for
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inflow for coronary grafts. Previous reports have outlined the technical aspects of the procedure and demonstrated feasibility [5–7]. The procedure provides an option during a MIDCAB procedure when the left internal mammary artery is injured or has inadequate flow [8]. Use of the axillary artery can also be helpful during a standard CABG operation when the ascending aorta is calcified or severely atherosclerotic [9]. The axillary artery is only rarely the site of significant arteriosclerosis, even in the presence of peripheral vascular or cerebrovascular disease. The high risk for stroke from atherosclerotic emboli in patients with a diseased aorta has been well documented. Bonatti and colleagues [10] have reported good, short-term results using the axillary artery in a series of patients with a diseased ascending aorta. This is an excellent concept and should be more widely used in these difficult patients. This is not a difficult operation, but a few comments about technical details are in order. We use a 4-mm punch to create the site for the proximal anastomosis on the axillary artery. This provides a fuller proximal anastomosis and avoids distortion of the axillary artery. In addition, the graft should be tunneled beneath the subclavian vein, rather than above it, to avoid compression of the vein and to provide a better anatomic position for the graft. Lastly, a wide incision should be made in the medial aspect of the first interspace to prevent compression of the graft as it enters the chest. Others have recommended partial rib resection, but we have not found this to be necessary if the intercostal incision is wide enough to admit two fingers [11]. Tunneling of the graft under the pectoralis major muscle before entering the thoracic cavity in the third or fourth interspace has also been advocated, but we have not used this approach [6]. This study has several limitations. This is a small series and more patients are needed to gain a fuller and more varied experience with the operation. In addition, we do not have extensive follow-up data, except survival and the need for reintervention. Stress testing and angiography have not been systematically obtained. Duplex scanning of the graft would be an excellent, noninvasive method for documenting late patency, but we have no data on this technique. Nonetheless, the functional status of the patients has been surprisingly good, and we do not have any reasons to be concerned about late graft patency. Finally, this is an uncommon operation, which in this series comprised approximately 0.25% of patients having CABG during the study period. The most common indication is the need for revascularization of the LAD in a high-risk patient with an occluded left internal mammary artery to LAD graft. Thus, the LAX-LAD procedure is a niche operation, but one that is simple, reliable, and effective when it is needed. In summary, a modified MIDCAB procedure using the saphenous vein or radial artery for an LAX to LAD graft is an effective method for revascularization of selected patients who are poor candidates for a traditional redo CABG. Operative morbidity and mortality are low and initial postoperative results are excellent. This procedure
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Fig 2. Functioning left axillary artery to left anterior descending coronary artery saphenous vein graft. (Top) Proximal anastomosis. (Bottom) Distal filling of the left anterior descending coronary artery.
should be considered when a patient with an occluded left internal mammary artery to LAD graft requires surgical revascularization of the LAD.
References 1. Landreneau RJ, Mack MJ, Magovern JA, et al. Keyhole coronary artery bypass surgery. Ann Surg 1996;224:453– 62. 2. Calafiore AM, Giammarco GD, Teodori G, et al. Left anterior descending coronary artery grafting via left anterior small thoracotomy without cardiopulmonary bypass. Ann Thorac Surg 1996;61:1658– 65. 3. Mack MJ, Magovern JA, Acuff, TA, et al. Results of graft patency by immediate angiography in minimally invasive coronary artery surgery. Ann Thorac Surg 1999;68:383–90. 4. Magovern JA, Benckart DH, Landreneau RJ, Sakert T, Magovern GJ Jr. Morbidity, cost and six-month outcome of minimally invasive direct coronary artery bypass grafting. Ann Thorac Surg 1998;66:1224–9. 5. Coulson AS, Bakhshay SA. Subclavian artery origin for a coronary bypass graft. Contemp Surg 1997;50:65– 6.
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6. Knight WL, Baisden CE, Reiter CG. Minimally invasive axillary-coronary artery bypass. Ann Thorac Surg 1997;63: 1776–7. 7. Tovar EA, Blau N, Borsari A. Axillary artery-coronary artery bypass grafting. J Thorac Cardiovasc Surg 1998;115:242–3. 8. Machiraju VR, Culig MH, Heppner RL, Minella RA, O’Toole JD. Value of reversed saphenous vein in minimally invasive direct coronary artery bypass graft procedures. Ann Thorac Surg 1998;65:625–7.
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9. Bonatti J, Hangler H, Antretter H, Muller LC. Axillocoronary bypass for severely atherosclerotic aorta in coronary artery bypass grafting. J Thorac Cardiovasc Surg 1998;115:956–7. 10. Bonatti J, Hangler H, Oturanlar D, et al. Beating heart axillocoronary bypass for management of the untouchable ascending aorta in coronary artery bypass grafting. Eur J Cardiothorac Surg 1999;16(Suppl):S18 –23. 11. Tovar EA. The route of choice for the axillocoronary bypass graft. J Thorac Cardiovasc Surg 1998;116:1086–7.
Discussion Groups on the Internet The following three articles will be published in the March 2001 issue of The Annals of Thoracic Surgery, and have been selected for discussion topics on the Internet. These discussion groups can be accessed by going to the Society of Thoracic Surgeons Home Page (http://www.sts.org) and clicking on “Discussion Forums.” We encourage everyone to participate, as our goal is to make the discussion as interactive as possible.
Coronary Artery Bypass Combined With Bilateral Carotid Endarterectomy
Individualized Heparin and Protamine Management in Infants and Children Undergoing Cardiac Operations Massimiliano Codispoti, MD, Christopher A. Ludlam, PhD, David Simpson, FRCA, and Pankaj S. Mankad, PhD
Role of Apolipoprotein E in Cognitive Decline After Cardiac Operation Liz Steed, MSc, Robert Kong, FRCA, Jan Stygall, MSc, Jayshree Acharya, PhD, Manjeet Bolla, MSc, Michael J. G. Harrison, FRCP, Steve E. Humphries, PhD, and Stanton P. Newman, DPhil Tom R. Karl, MD
Mark Dylewski, MD, Charles C. Canver, MD, Jyotirmay Chanda, MD, PhD, R. Clement Darling III, MD, and Dhiraj M. Shah, MD
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