Ann Thorac Surg 2007;84:1768-1770. doi:10.1016/j.athoracsur.2007.07.041
© 2007 The Society of Thoracic Surgeons
How To Do It
Repair of Separated Coronary Segments Resulting From a Complicated Coronary Endarterectomy
Du
ko G. Ne
i
, MD, PhDa,*,
Aleksandar M. Knezevic, MD, BSa,
Zelimir D. Antonic, MDb,
Miomir Dj. Jovic, MD, PhDc
a Department of Cardiac Surgery, "Dedinje" Cardiovascular Institute, Belgrade, Serbia
b Department of Radiology, "Dedinje" Cardiovascular Institute, Belgrade, Serbia
c Department of Anesthesiology, "Dedinje" Cardiovascular Institute, Belgrade, Serbia
Accepted for publication July 16, 2007.
* Address correspondence to Dr Nei, Department of Cardiac Surgery I, "Dedinje" Cardiovascular Institute, Heroja M. Tepia 1, Belgrade, 11000, Serbia (Email: nezic{at}eunet.yu).
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Abstract
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Cardiac surgeons are treating an increasing number of patients with diffuse coronary artery disease that requires the use of alternative surgical techniques. We present a patient who had a technically unsatisfactory endarterectomy of the left anterior descending coronary artery. We were left with only 3 segments of properly endarterectomized coronary bed areas, separated with totally disintegrated coronary bed portions. These 3 segments were incorporated into the venous graft, with the inflow obtained from the left internal thoracic artery. We believe that this approach may be the rescue technique for complicated coronary artery endarterectomy.
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Introduction
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The rapidly growing use of percutaneous coronary intervention for myocardial revascularization has led to a fundamental change in the patient subset referred for coronary artery bypass grafting (CABG) procedures. Therefore, surgeons are facing with an increasing number of patients with advanced and diffuse coronary artery disease (CAD). Diffusely diseased coronary arteries often require the use of complementary revascularization techniques. We describe an alternative technique to solve the problem of unsatisfactory endarterectomy of the left anterior descending (LAD) coronary artery.
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Technique
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A 54-year-old man was admitted with progressive angina and was at New York Heart Association (NYHA) class III. His history revealed hypertension, smoking, hypercholesterolemia, and insulin-dependent type 2 diabetes mellitus as risk factors for CAD. Cardiac catheterization showed preserved left ventricular function (ejection fraction, 0.60) and severe triple-vessel disease. There was a 90% stenosis of the right coronary artery at the crux level, occlusion of the circumflex coronary artery, and the occluded LAD (supplying viable myocardium) was vaguely filled by collaterals from the right coronary artery.
CABG using pedicled left internal thoracic artery (LITA) and vein grafts was planned. Myocardial protection was achieved by induction of antegrade and retrograde cold-blood cardioplegia. The vein graft was used to bypass the right coronary system. To revascularize the diffusely and heavily calcified circumflex coronary artery was an impossible task.
The procedure on the diffusely diseased LAD was started as a classic open endarterectomy. Unfortunately, the endarterectomy converted to a technically unsatisfactory procedure due to the lack of a proper plane for dissection in some portions of the LAD. Finally, along 9-cm of endarterectomized LAD area, only 3 segments of properly endarterectomized LAD were left (the diseased intima had been neatly removed with virtually all the media, leaving external elastic lamina and adventitial tissue [1]), separated with totally disintegrated coronary bed areas. The first segment was in the proximal LAD portion (including one septal and one diagonal branch), the middle segment contained a small septal branch, and the third extended as a very distal part of the LAD.
Because we were reluctant to ligate the LAD supplying viable myocardium, we decided to incorporate all 3 segments in a venous graft in which the proximal and distal segments were connected with the venous graft in an end-to-end fashion and the middle one in an end-to-side manner. Finally, the LITA was anastomosed end-to-side to the venous graft. The aortic cross-clamp time was 73 minutes.
The patient was easily weaned from the cardiopulmonary bypass. His postoperative course and convalescence progressed without any difficulty. The results of the postoperative electrocardiogram and cardiac-specific enzyme levels were normal. Anticoagulation (warfarin sodium), which was started on the first postoperative day, would be continued for the next 6 months to maintain an international normalized ratio of 2.0 to 2.5.
Postoperative transthoracic echocardiography confirmed no change in the ejection fraction. On postoperative day 8, a 64-slice multidetector row computed tomography scan confirmed the patency of the LITA graft as well as the sequential venous graft connecting LAD segments, thus reconstructing the LAD coronary bed (Figs 1 and 2.).
The patient had regular follow-up for the next 3 months and is in NYHA class I with a normal stress test result.
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Fig 1. (A) A 3-dimensional volume-rendered image with multisegment reconstruction depicts the patent left internal thoracic artery (lita) graft attached to patent venous graft reconstructing the left anterior descending (LAD) artery coronary bed. The crescents indicate 3 successfully endarterectomized LAD segments incorporated into the vein graft. (B) A purified 3-dimensional volume-rendered image depicts patent native distal LAD bed (dashed arrow) and patent venous graft (arrows). (dg = diagonal branch.)
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Fig 2. Coronary artery composite graft. Sequential venous graft (crescents indicate 3 successfully endarterectomized left anterior descending artery segments, dashed arrows indicate septal branches) plus left internal thoracic artery conduit patency at 64-slice row multidetector computed tomographic angiography. (Inset A) Purified three-dimensional volume rendered image shows patent composite graft. (dg = diagonal branch; dashed arrow indicates the middle segment septal branch.)
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Comment
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Complete revascularization of all occluded or significantly stenosed coronary arteries that supply viable myocardium yields the best long-term results and should be the primary goal in CABG surgery. Nowadays cardiac surgeons are confronted with an increasing number of patients with diffuse CAD disease that require the use of alternative surgical techniques. Complementary surgical revascularization techniques include extensive reconstruction of the LAD with an autologous vein patch (with or without the plaque exclusion technique) completed by ITA grafting onto the patch [2] or using an on-lay ITA patch [3], as well as multiple sequential grafting [4] on a single vessel, and coronary artery endarterectomy [5]. Although the benefits of the LAD endarterectomy have been reported [5, 6], many surgeons are still reluctant to use this technique because of its higher perioperative and postoperative morbidity and mortality rates.
Another major concern with coronary artery endarterectomy is the development of myofibrointimal proliferation, which impairs early and long-term clinical and angiographic results. After endarterectomy, denuded endothelium enhances myofibroblast proliferation [1]. The endarterectomized arterial wall acts as a trigger for the new thrombus formation. An increase of platelet-activating factor was observed in damaged LADs in a canine model and in endarterectomy samples that were taken from the severely diseased coronary arteries of patients with diffuse CAD [7].
Although it seems that reconstructive techniques offer better results [2, 3], it is sometimes impossible to avoid coronary artery endarterectomy. Almost 1% of such attempts led to technically unsatisfactory procedure [5]. The incidence of postoperative myocardial infarction if those vessels were ligated was 40% [5]. Thus, being reluctant to ligate the LAD that was supplying viable myocardium after a technically unsatisfactory coronary artery endarterectomy, we decided to repair the separated LAD segments. All successfully endarterectomized LAD segments were incorporated into a venous graft, with the inflow obtained from the LITA. In such a manner, the endarterectomized area is reduced due to the exclusion of totally disintegrated LAD areas and endothelial covering might be achieved rapidly, decreasing the risk of thrombus formation in the early stage and myofibrointimal proliferation later on. We strongly believe that such an approach to solve a problem of complicated LAD endarterectomy may sometimes be a good rescue technique for a complicated coronary artery endarterectomy.
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References
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- Walley V, Byard R, Keon W. A study of the sequential morphologic changes after manual coronary endarterectomy J Thorac Cardiovasc Surg 1991;102:890-894.[Abstract]
- Bernet F, Hirschmann M, Reineke D, Grapow M, Zerkowski H. Clinical outcome after composite grafting of calcified left anterior descending arteries J Cardiovasc Surg (Torino) 2006;47:569-574.[Medline]
- Ogus TN, Basaran M, Selimoglu O, et al. Long-term results of the left anterior descending coronary artery reconstruction with left internal thoracic artery Ann Thorac Surg 2007;83:496-501.[Abstract/Free Full Text]
- Nezic D, Knezevic A, Milojevic P, Jovic M, Sagic D, Djukanovic B. Tandem pedicled internal thoracic artery conduit for sequential grafting of multiple left anterior descending coronary artery lesions Tex Heart Inst J 2006;33:469-472.[Medline]
- Sirivella S, Gielchinsky I, Parsonnet V. Results of coronary artery endarterectomy and coronary artery bypass grafting for diffuse coronary artery disease Ann Thorac Surg 2005;80:1738-1745.[Abstract/Free Full Text]
- Byrne J, Karavas A, Gudbjartson T, et al. Left anterior descending coronary endarterectomy: early and late results in 196 consecutive patients Ann Thorac Surg 2004;78:867-874.[Abstract/Free Full Text]
- Mueller H, Haught C, McNatt J, et al. Measurement of platelet-activating factor in a canine model of coronary thrombosis and in endarterectomy samples from patients with advanced coronary artery disease Circ Res 1995;77:54-63.[Abstract/Free Full Text]
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eComment: Islets technique to reduce endarterectomized area included into graft during left anterior descending coronary artery endarterectomy
Interactive CardioVascular and Thoracic Surgery,
June 1, 2009;
8(6):
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Abstract
Introduction
