HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Inderjit S. Gill W. Douglas Boyd Wilbert J. Keon Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gill, I. S. Articles by Keon, W. J. Search for Related Content PubMed PubMed Citation Articles by Gill, I. S. Articles by Keon, W. J.

Ann Thorac Surg 1998;65:659-662
© 1998 The Society of Thoracic Surgeons

---

Original Articles: Cardiovascular

Left Anterior Descending Endarterectomy and Internal Thoracic Artery Bypass for Diffuse Coronary Disease

Department of Cardiothoracic Surgery and Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario, Canada

Accepted for publication August 29, 1997.

Dr Gill, University of Ottawa Heart Institute, Ottawa Civic Hospital, 1053 Carling Ave, Ottawa, Ontario, K1Y 4E9 Canada.

	Abstract

Top Abstract Introduction Patients and Methods Results Comment References

 
Background. The risk and efficacy of using an arterial conduit to bypass an endarterectomized coronary artery remain incompletely defined. To address this question we analyzed retrospectively 74 patients from 1989 to 1994 in whom bypass grafting using the left internal thoracic artery to an endarterectomized left anterior descending artery was performed.

Methods. There were 60 men and 14 women with a mean age of 60.1 ± 8.6 years. Of this cohort, 55 patients (74.3%) had a previous infarction, 18 (24.3%) were diabetic, and 5 (6.7%) had reoperations; 25 patients (34%) had a totally occluded left anterior descending artery and the average ejection fraction was 45%. Each patient had 2.95 ± 0.52 grafts with 48 patients (65%) requiring multiple endarterectomies. The average length of the endarterectomized segment was 3.1 ± 1.6 cm. Average anoxia time was 49 ± 13 minutes. Postoperatively 19 patients (25.6%) required intraaortic balloon and 18 (24.3%) required inotropic support. Perioperative infarction in the left anterior descending artery distribution occurred in 5 patients (6.7%).

Results. There were 3 (4.0%) early and 4 (5.4%) late deaths at a mean follow-up of 36 ± 16 months. Recurrent angina was present in 9 patients (14.7%). Actuarial 5-year survival was 84.5%. Angiographic follow-up obtained in 23 patients (37.4%) demonstrated 74% anastomotic patency, with good distal run-off in 13 (65%). The anterior segmental wall motion was preserved.

Conclusions. The use of the left internal thoracic artery bypass and adjunctive left anterior descending artery endarterectomy to expand the scope of myocardial revascularization in carefully selected circumstances appears to be beneficial.

	Introduction

Top Abstract Introduction Patients and Methods Results Comment References

 
The primary goal in the surgical management of coronary artery disease is to obtain revascularization of all occluded or significantly stenosed coronary arteries that supply viable myocardium [1]. When the coronary artery disease is local it is technically possible to perform a direct anastomosis with reversed saphenous vein graft or arterial conduits. However, when the coronary artery is diffusely diseased (ie, has diffuse calcification involving most or all of its epicardial portion or it has multiple areas of stenosis) the goal of complete revascularization can be achieved only by performing an endarterectomy as proposed by Bailey and colleagues [2]. Incomplete revascularization with residual disease specifically of the left anterior descending artery (LAD) is an independent variable affecting both perioperative and late mortality [3].

Several studies have attested to the feasibility of coronary endarterectomy and saphenous vein grafting [4][5][6]. Saphenous vein graft atherosclerosis, however, is the principal cause of recurrent angina. The use of a saphenous vein graft to the LAD is also a significant independent predictor of late mortality [7].

Concerns about hypoperfusion of the recipient endarterectomized vessel and the size mismatch have prevented surgeons from using the internal thoracic artery (ITA) as a conduit in spite of the proven patency and long-term survival provided by it [8]. We therefore analyzed patients in whom bypass grafting using the ITA to an endarterectomized LAD was performed to assess the surgical risk and efficacy of this procedure.

	Patients and Methods

Top Abstract Introduction Patients and Methods Results Comment References

 
Between July 1972 and June 1994, 2,483 patients underwent 2,859 coronary bypass procedures combined with an endarterectomy at the University of Ottawa Heart Institute. They constituted 21.9% of all patients undergoing coronary bypass grafting. Between July 1989 to June 1994, 442 patients underwent coronary endarterectomy, and 74 (16.7%) had an internal thoracic artery used to bypass an endarterectomized LAD.

Data were collected by hospital chart reviews and late follow-up was conducted using a telephone survey and a postal questionnaire. All 61 surviving patients were required to undergo postoperative angiography; 23 patients (37.3%) agreed and the remainder declined because of reasons of distance (7 patients), risk involved (5), or because they were asymptomatic (22) or had other health problems (4 patients).

There were 60 men (81%) and 14 women (19%) and the average age was 60.1 ± 8.6 years. Preoperatively 17 (23%) were smokers, hypertension was present in 31 (41.9%), and 18 patients (24.4%) were diabetic. Previous myocardial infarction was present in 55 (74.33%), and 6 (8.1%) had a previous percutaneous transluminal coronary angioplasty and 5 (6.8%) previous coronary artery bypass grafting. Class III or IV anginal symptoms were present in 48 patients (64.8%).

Preoperative angiographic data for the entire series (74 patients) showed >50% right coronary stenosis in 69 patients (93.2%), >50% left anterior descending stenosis in 72 patients (97.3%), 100% LAD occlusion in 25 (33.8%), >50% circumflex stenosis in 49 patients (66.2%), and >50% left main stenosis in 4 patients (5.4%). The average ejection fraction was 0.45 in 23 patients who eventually underwent postoperative angiography; preoperative studies were available in 20:

LAD disease Mild 4 (20%) Moderate 5 (25%) Severe 8 (40%) Occluded 3 (15%) Filling Prograde 14 (70%) Retrograde 4 (20%) Both 2 (10%)

All operations were conducted under total cardiopulmonary bypass, moderate hypothermia (32°C), and antegrade crystalloid cardioplegic arrest. Manual endarterectomy with extraction of the distal core was performed by enlarging the arteriotomy 10 to 12 mm. No attempt was made to extract the core proximally. In vessels with multiple areas of stenosis, the endarterectomy was attempted at the most distal site of narrowing. Intraaortic balloon counterpulsation was used prophylactically postoperatively in 19 patients (25.6%) undergoing multiple endarterectomies to augment cardiac output and reduce the risk of internal thoracic artery spasm. Inotropic support (ie, dopamine and dobutamine 5 µg/kg/min) was need in 18 patients (24.3%). Each patient had 2.95 ± 0.52 grafts, the mean anoxia time was 49.3 ± 13.4 minutes, and the mean pump time was 93.9 ± 26.9 minutes. One patient had an additional aortic valve replacement and 4 patients had plication of left ventricular aneurysms. The mean segment length extracted was 3.1 ± 1.59 cm and 48 patients (63.9%) had multiple endarterectomies (LAD + right coronary artery [RCA], 36 patients; LAD + diagonal, 3; LAD + circumflex, 1; LAD + RCA + diagonal, 2; and LAD + RCA + circumflex, 6 patients).

Postoperatively the patients were given intravenous heparin, 2,500 IU every 6 hours for 48 hours. Then warfarin administration to maintain an international normalized ratio of 2.0 to 2.5 was initiated and continued for 1 year. Aspirin was started immediately postoperatively and was continued indefinitely.

Preoperative and postoperative angiograms were reviewed in a blinded fashion. The definitions used to analyze them are given in Fig 1.

View larger version (29K): [in this window] [in a new window]   Angiographic definitions used for assessing preoperative and postoperative angiograms. (ds = disease; LAD = left anterior descending artery; LITA = left internal thoracic artery; LV = left ventricular; RAO = right anterior oblique.)

	Results

Top Abstract Introduction Patients and Methods Results Comment References

 
Early mortality was defined as death occurring within 30 days of operation. There were three early deaths (4.0%). The causes were perioperative myocardial infarction and multiorgan failure, sudden cardiac arrest, and low cardiac output and multiorgan failure (1 patient each).

Five patients (6.7%) sustained a perioperative myocardial infarction in the LAD territory. As 65% of the patients had multiple endarterectomies, myocardial infarction only in the left anterior descending territory were considered and electrocardiographic criteria were used. The overall incidence of perioperative infarctions was 21.6% (16 of 74 patients).

Ventricular arrhythmias developed in 6 patients (6.7%). Two of these had sustained a perioperative infarction by enzyme criteria; renal failure developed in only 3 patients (4.1%) and respiratory failure in 4 (5.4%).

The mean intensive care unit stay was 4.8 ± 6.7 days, and the mean hospital stay was 15.2 ± 11.3 days. Delayed tamponade developed in 2 patients (2.7%).

Late mortality was defined as death occurring after 30 days, and after a mean follow-up of 35.6 ± 16.2 months there were 4 (6.6%) late deaths. Recurrent angina was present in 9 (14.7%) of the survivors and 3 patients (4.9%) had recatheterization for angina, and of those 2 (3.2%) underwent angioplasty to vessels other than the left anterior descending. One patient (1.6%) had a transplant. There have been no reoperations.

Six patients were lost to follow-up. The 5-year actuarial survival rate was 84.5% (Fig 2). Anastomotic patency was demonstrated in 74% (17), with distal run-off judged to be good in 15 patients (65%) (Table 1). The left ventricular anterior segmental wall motion showed a trend toward improvement, although it did not reach statistical significance (Table 2).

View larger version (9K): [in this window] [in a new window]   Five-year actuarial survival.

View larger version (16K): [in this window] [in a new window]   Comparison of preoperative and postoperative distal left anterior descending run-off.

	Comment

Top Abstract Introduction Patients and Methods Results Comment References

Quereshi and associates [11] reported a hospital mortality of 4% and a perioperative myocardial infarction rate of 12% in 278 patients with an endarterectomy of the left coronary system bypassed with saphenous vein. This study included 250 endarterectomies of the LAD. Ladowsky and associates [12] reported 18 patients in whom an "open" endarterectomy of the LAD was performed in combination with a saphenous vein patch to which an ITA graft was anastomosed. They reported an 11.1% perioperative infarction rate with 5.5% recurrent angina at 12 months of follow-up.

The perioperative morbidity of our series is in keeping with data from other published series. Thirty-day mortality reported by Brenowitz and colleagues [5] is 6.3% for patients with a single endarterectomy and 10.4% in patients with multiple endarterectomies. Our operative mortality was 4%, with 65% of patients needing multiple endarterectomies.

Late LAD vein graft patency data from the same series at an average of 31.4 months were 72.6% (69 of 95 patients). This compares favorably with our results demonstrating 74% anastomotic patency at 36 ± 16 months. The patency of vein grafts to an endarterectomized LAD reported by Quereshi and colleagues [11] restudied at 2 weeks to 1 year is 83% (156 of 188 patients). We also have earlier reported a patency of 83% (15 of 18) in vein grafts to an endarterectomized LAD at a mean of 9 weeks [13].

The advantage of the ITA graft, however, is likely to persist as vein graft atherosclerosis becomes a significant cause of recurrent angina beyond 5 years [14]. The incidence of recurrent angina in our series (14.7%) at 36 ± 16 months is considerably less than 33.7% at 58 months reported by Brenowitz and colleagues [5] using vein grafts.

The intramyocardial septal branches are usually disease free and endarterectomizing the epicardial diseased segment is sufficient to restore flow. Therefore, we perform distal core extraction by enlarging the arteriotomy only to 10 to 12 mm. This also prevents size mismatch. We do not use the open technique, which would necessitate a vein patch. This results in unacceptably long anoxia and cross-clamp times. We could also demonstrate that anterior wall motion was preserved by our technique.

The 5-year actuarial survival (84.5%) compares favorably with other published series [4][5], which varies from 92% to 36% although is is difficult to make direct comparisons.

In conclusion, the use of ITA bypass to an endarterectomized LAD in patients with diffuse coronary disease, many of whom would otherwise be inoperable, appears to be beneficial based on our early results, late survival, stable clinical status, acceptable graft patency in this setting, and preserved anterior wall motion.

	References

Top Abstract Introduction Patients and Methods Results Comment References

 

1. Cukingnan RA, Cavey JS, Wittig JH, et al. Influence of complete revascularization on relief of angina. J Thorac Cardiovasc Surg 1980;79:188-193.[Medline]
2. Bailey CP, May A, Newman WM Survival after coronary endarterectomy in man. JAMA 1957;164:641-647.
3. Lawrie GM, Morris GC, Silvers A, et al. The influence of residual disease after coronary bypass on the 5–10 survival rate of 1274 men with coronary artery disease. Circulation 1982;66:717-723.[Free Full Text]
4. Livesay JJ, Cooley DA, Hallman GL, et al. Early and late results of coronary endarterectomy: analysis of 3,369 patients. J Thorac Cardiovasc Surg 1986;92:649-660.[Abstract]
5. Brenowitz JB, Kayser KL, Johnson WD Results of coronary endarterectomy and reconstruction. J Thorac Cardiovasc Surg 1988;95:1-10.[Abstract]
6. Keon WJ, Hendry P, Boyd WD, et al. Long term follow up of coronary endarterectomy. In: Walter PJ, ed. . Treatment of end stage coronary artery disease. Basel, Karger: Adv. Cardiol, 1988:19-26.
7. Lytle BW, Loop FD, Taylor PC, et al. Vein graft disease: the clinical impact of stenosis in saphenous vein bypass grafts to coronary arteries. J Thorac Cardiovasc Surg 1992;103:831-840.[Abstract]
8. Loop FD, Lytle BW, Cosgrove DM, et al. Influence of internal mammary artery graft on 10 year survival and other cardiac events. N Engl J Med 1986;314:1-6.[Abstract]
9. Dodge HT, Sandler H, Ballew EW, et al. Use of biplane angio-cardiography for the measurement of left ventricular volume in man. Am Heart J 1960;60:762-776.[Medline]
10. Barkson J, Gage RP Calculation of survival rates for cancer. Mayo Clinic Proc 1950;25:270-286.[Medline]
11. Quereshi SA, Halim MA, Pillai R, et al. Endarterectomy of the left coronary system. Analysis of a 10 year experience. J Thorac Cardiovasc Surg 1985;89:852-859.[Abstract]
12. Ladowsky JS, Schatzlein MH, Underhill DJ, et al. Endarterectomy, vein patch and mammary bypass of the anterior descending artery. Ann Thorac Surg 1991;52:1187-1189.[Abstract]
13. Morton BC, Beanlands DS, Chambers RJ, et al. Fate of the graft and native vessel following endarterectomy of the left anterior descending coronary artery. Canadian J Surg 1979;22:142-144.[Medline]
14. FitzGibbon GM, Leach AJ, Keon WJ, et al. Coronary bypass graft fate: angiographic study of 1179 vein grafts early, one year and 5 years after operation. J Thorac Cardiovasc Surg 1986;91:773-778.[Abstract]

This article has been cited by other articles:

				E. Gongora and T. M. Sundt III Myocardial Revascularization with Cardiopulmonary Bypass Card. Surg. Adult, January 1, 2008; 3(2008): 599 - 632. [Full Text]

				T. N. Ogus, M. Basaran, O. Selimoglu, T. Yildirim, H. Ogus, H. Ozcan, and M. H. Us Long-Term Results of the Left Anterior Descending Coronary Artery Reconstruction With Left Internal Thoracic Artery Ann. Thorac. Surg., February 1, 2007; 83(2): 496 - 501. [Abstract] [Full Text] [PDF]

				F. Nurozler, T. Kutlu, G. Kucuk, and C. Okten Off-Pump Coronary Endarterectomy in High-Risk Patients Asian Cardiovasc Thorac Ann, June 1, 2006; 14(3): 227 - 230. [Abstract] [Full Text] [PDF]

				H. A. Vohra, R. Kanwar, T. Khan, and W. R. Dimitri Early and late outcome after off-pump coronary artery bypass graft surgery with coronary endarterectomy: a single-center 10-year experience. Ann. Thorac. Surg., May 1, 2006; 81(5): 1691 - 1696. [Abstract] [Full Text] [PDF]

				T. Fukui, S. Takanashi, and Y. Hosoda Long Segmental Reconstruction of Diffusely Diseased Left Anterior Descending Coronary Artery With Left Internal Thoracic Artery With or Without Endarterectomy Ann. Thorac. Surg., December 1, 2005; 80(6): 2098 - 2105. [Abstract] [Full Text] [PDF]

				S. Sirivella, I. Gielchinsky, and V. Parsonnet Results of Coronary Artery Endarterectomy and Coronary Artery Bypass Grafting for Diffuse Coronary Artery Disease Ann. Thorac. Surg., November 1, 2005; 80(5): 1738 - 1744. [Abstract] [Full Text] [PDF]

				H. Nishi, S. Miyamoto, S. Takanashi, H. Minamimura, T. Ishikawa, Y. Kato, and Y. Shimizu Optimal Method of Coronary Endarterectomy for Diffusely Diseased Coronary Arteries Ann. Thorac. Surg., March 1, 2005; 79(3): 846 - 852. [Abstract] [Full Text] [PDF]

				J. G. Byrne, A. N. Karavas, T. Gudbjartson, M. Leacche, J. D. Rawn, G. S. Couper, R. J. Rizzo, L. H. Cohn, and S. F. Aranki Left anterior descending coronary endarterectomy: Early and late results in 196 consecutive patients Ann. Thorac. Surg., September 1, 2004; 78(3): 867 - 873. [Abstract] [Full Text] [PDF]

				M. A. Ruel, F. Wang, M. E. Bourke, J.-Y. Dupuis, J. A. Robblee, W. J. Keon, and F. D. Rubens Is tranexamic acid safe in patients undergoing coronary endarterectomy? Ann. Thorac. Surg., May 1, 2001; 71(5): 1508 - 1511. [Abstract] [Full Text] [PDF]

				O. M. Shapira, G. Akopian, A. Hussain, M. Adelstein, H. L. Lazar, G. S. Aldea, and R. J. Shemin Improved clinical outcomes in patients undergoing coronary artery bypass grafting with coronary endarterectomy Ann. Thorac. Surg., December 1, 1999; 68(6): 2273 - 2278. [Abstract] [Full Text] [PDF]

				T. M. Sundt III, C. J. Camillo, E. N. Mendeloff, H. B. Barner, and W. A. Gay Jr Reappraisal of coronary endarterectomy for the treatment of diffuse coronary artery disease Ann. Thorac. Surg., October 1, 1999; 68(4): 1272 - 1277. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Inderjit S. Gill W. Douglas Boyd Wilbert J. Keon Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gill, I. S. Articles by Keon, W. J. Search for Related Content PubMed PubMed Citation Articles by Gill, I. S. Articles by Keon, W. J.