Coronary artery bypass grafting (CABG) increases life

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1 Coronary Artery Reconstruction for Extensive Coronary Disease: 108 Patients and Two Year Follow-up Jean-Aubert Barra, MD, Eric Bezon, MD, Philippe Mondine, MD, Ahmed Resk, MD, Martine Gilard, MD, and Jacques Boshat, MD Service de Chirurgie Cardiaque, Thoracique et Vasculaire, CHU Hôpital de la Cavale Blanche, Brest, France Background. Surgical coronary artery reconstruction for diffuse coronary disease is described and assessed. Methods. A long arteriotomy, internal thoracic artery graft, and exclusion of atheromatous plaques from the coronary lumen are the bases of the technique. One hundred eighteen reconstructions were performed in 108 patients with a mean age of 59 years. Stable angina was present in 62% of patients and unstable angina in 22%. Sixteen percent had had a recent myocardial infarction. The reconstructions involved 94 left anterior descending coronary arteries, 17 marginal, 5 diagonal, and 2 right coronary arteries. Results. The perioperative mortality rate was 3.7% (4 patients). The rate of perioperative myocardial infarction was 6.3%. Mean follow-up was 29 months (standard deviation, 10 months). Two patients were lost to followup. Ninety patients were free from angina and cardiacrelated events. Five patients sustained a myocardial infarction, 3 were in congestive heart failure, 3 had class II angina, and 1 died of stroke. Seventy-four of the surgical coronary artery reconstructions have been angiographically evaluated (29 months): 94.6% of the internal thoracic artery grafts were completely patent, and 70 of the reconstructions were patent without restenosis. String signs and occlusions were present in two internal thoracic arteries each. Conclusions. This technique allows revascularization of severely and diffusely diseased coronary arteries with encouraging results. (Ann Thorac Surg 2000;70:1541 5) 2000 by The Society of Thoracic Surgeons Coronary artery bypass grafting (CABG) increases life expectancy and improves quality of life [1]. Use of the internal thoracic artery (ITA), the conduit of choice [2], decreases the rate of redo operations [3, 4]. In the Coronary Artery Surgery Study [5], extensive and calcified lesions could not be treated surgically in 4.9% of diseased coronary arteries. Coronary artery bypass grafting associated with open endarterectomy through a long arteriotomy closed with a vein patch has been described [6 8]. Anastomosing the ITA graft to the vein patch improves postoperative results, but intimal hyperplasia remains the major drawback [9, 10]. We have developed a technique of coronary artery reconstruction (CAR) in which atheromatous plaques are left outside the lumen of the reconstructed vessel. This technique decreases the need of a long endarterectomy in the case of diffuse and extensive coronary artery disease. The aim of this study is to evaluate the postoperative results of our CAR technique. Accepted for publication April 17, Address reprint requests to Dr Barra, Service de Chirurgie Cardiaque, Thoracique et Vasculaire, CHU Hôpital de la Cavale Blanche, Brest, France; jean-aubert-barra@wanadoo.fr. Material and Methods Surgical Technique Coronary artery reconstruction is a new way to perform CABG anastomosis when there are severe and extensive atheromatous plaques downstream from the first major proximal lesions. The ITA is used as the arterial graft. A long arteriotomy is made in the diseased coronary artery. The tip of the arteriotomy reaches the healthy distal part of the vessel. The coronary artery at the level of the first major proximal lesion is neither opened nor reconstructed to avoid competitive flow between the ITA and the native artery. Coronary artery reconstruction is performed by covering the arteriotomy with an ITA onlay graft in such a fashion as to exclude atheromatous plaques from the lumen of the coronary artery (Fig 1). U-shaped running sutures are used to fix the ITA patch inside the lumen of the diseased coronary vessel (see Fig 1). The ITA wall makes up 75% of the reconstructed vessel, and the newly reconstructed artery retains 25% of the native coronary artery, which contains the origins of the collateral arteries. For instance, in reconstruction of the left anterior descending coronary artery (LAD), the native artery forms a posterior gutter in which the origins of the septal and diagonal branches are found. In some instances, the needle cannot be passed through calcified plaques. Under these circumstances, a small and limited endarterectomy is performed with 2000 by The Society of Thoracic Surgeons /00/$20.00 Published by Elsevier Science Inc PII S (00)

2 1542 BARRA ET AL Ann Thorac Surg CORONARY RECONSTRUCTION FOR EXTENSIVE DISEASE 2000;70: When the LAD is involved, CAR is performed if a diagonal LAD sequential anastomosis is impossible or poses a risk. A long ITA graft is needed when the CAR exceeds 4 cm. A good way to obtain a long ITA graft is to implant the right ITA (used as a free graft) into the left ITA. With this Y procedure, it is possible to reach the LAD up to the apex of the heart with the right ITA and to bypass one marginal artery with the left ITA. In any event, the ITA must be harvested from the inferior edge of the first rib to its distal bifurcation. Fig 1. Coronary artery reconstruction (CAR) is performed by covering a long arteriotomy with an internal thoracic artery (ITA) onlay graft. Cross-sectional view: (1) opening of coronary artery (Coro); (2) enlargement of lumen; and (3) CAR with ITA 75% ITA and 25% native artery. Surgical view: (4) exclusion of plaque (Plq) with intracoronary U-shaped running suture (USRS). (Diag diagonal artery; I incision; Spt septal artery.) proximal and distal intimal suture fixation (Fig 2). As with straightforward CAR, the major part of the endarterectomized arterial wall is excluded from the lumen of the reconstructed vessel. Twenty-five percent of the new vessel is an endarterectomized coronary vessel wall and 75%, an ITA wall (see Fig 2). A narrow gutter of endarterectomized wall remains in contact with the bloodstream. Fig 2. When a needle cannot pass through calcified plaques (CP), a limited and minimal endarterectomy (Endart) is performed. Crosssectional view: (1) opening of diseased artery; (2) endarterectomy of plaque (Plq); (3) endarterectomized coronary artery wall; and (4) exclusion of 75% of endarterectomized wall. Surgical view: (5) calcified plaque and (6) limited endarterectomy with proximal and distal intimal fixation. (Coro coronary artery; Diag diagonal artery; ITA internal thoracic artery; Spt septal artery.) Study Population The study includes 108 patients with diffuse extensive coronary artery disease requiring operation for myocardial revascularization from 1990 to The mean age of the patients was years, and 16.7% were women. The risk factors were as follows: hypercholesterolemia, 98 patients (90.7%); smoker, 74 patients (68.5%); hypertension, 53 patients (49.1%); obesity, 33 patients (30.6%); diabetes mellitus, 11 patients (10.2%); and a family history of coronary artery disease, 48 patients (44.4%). Each patient had at least three risk factors ( one factor). Clinically 67 patients (62%) had stable angina, 24 (22.2%) had unstable angina, 17 (15.7%) had had a recent myocardial infarction (MI), 48 (44.4%) had a history of MI, and 49 (45.4%) had associated vascular diseases or cerebrovascular ischemic events. Three patients had previously undergone CABG. All patients were on a regimen of antianginal medication; 11 patients (10.2%), one antianginal drug; 58 patients (53.7%), two antianginal drugs; and 39 patients (36.1%), three antianginal drugs. The average was 2.2 drugs per patient (standard deviation, 0.7). Twenty patients (18.5%) had a dilated left ventricle. There were 87 patients (80.6%) with at least one hypokinetic myocardial segment. The ejection fraction was less than 0.50 in 24 patients (22.2%). Mean ejection fraction was Fifteen patients (13.9%) had singlevessel coronary artery disease, 21 patients (19.4%) had two-vessel disease, and 72 patients (66.7%) had threevessel disease. Twenty-two patients (20.4%) had stenosis of the left main coronary artery, and 85 patients (78.7%) had coronary calcifications. The LAD was occluded in 21 patients (19.4%). In 25% of the patients, CAR was indicated as a result of the preoperative angiographic observations. In 19% of the patients, diffuse lesions not visible on the preoperative angiogram were discovered intraoperatively. In the remaining patients, atheromatous plaques along the distal bed of the stenosed coronary arteries were visible at angiography. However, intraoperative assessment revealed severe lesions requiring reconstruction. In these last two groups of patients, the decision to perform CAR was made during the operation. The purpose of CAR is to exclude from the lumen of the vessel as much of the atheromatous material as possible. Two hundred twenty-six bypass grafts were placed, an average of 2.1 grafts per patient: CABG 1 in 14 patients (13%); CABG 2 in 72 patients (66.7%); CABG 3in20

3 Ann Thorac Surg BARRA ET AL 2000;70: CORONARY RECONSTRUCTION FOR EXTENSIVE DISEASE 1543 Table 1. Coronary Arteries Involved in Coronary Artery Reconstruction Coronary Artery With Left ITA With Right ITA LAD DIAG 5 0 OM 9 8 RCA 0 2 DIAG diagonal coronary artery; ITA internal thoracic artery; LAD left anterior descending coronary artery; OM obtuse marginal branch; RCA right coronary artery. patients (18.5%); and CABG 4 in 2 patients (1.9%). The ITA was used for 181 grafts (80%), the saphenous vein for 41 (18.1%), the gastroepiploic artery for one graft, and the radial artery for one. One hundred eighteen CARs were performed with ITA material. Ten patients underwent two CARs. Coronary artery reconstructions by left and right ITAs are shown in Table 1. Coronary artery endarterectomy was necessary in 19 instances (16%) and involved 15 LADs, 2 diagonal arteries, and 2 marginal arteries. The mean length of the CAR was cm (range, 2.5 to 12 cm). In 31 patients (28.7%), the CAR was longer than 4 cm and involved 27 LADs and six marginal arteries. Endarterectomy was performed in 33.3% of the long reconstructions (n 11) versus 9.4% (n 46) of those less than 4 cm long. An intraaortic balloon was inserted in 3 patients preoperatively because of severe unstable angina. Myocardial protection was achieved with antegrade cold crystalloid cardioplegia in the first 45 patients and retrograde cold blood cardioplegia in the next 63 patients. The average time of aortic cross-clamping was minutes, and the average time of cardiopulmonary bypass was minutes. Data Analysis The operative results included weaning from cardiopulmonary bypass (difficult when the dosage of dobutamine hydrochloride was greater than 5 mg kg 1 min 1 or when epinephrine or an intraaortic balloon was needed), perioperative mortality (30 days), perioperative MI, low cardiac output, infections, cerebral complications, and organ failure. Two-year clinical assessment comprised clinical anginal status, MI, and number of antianginal drugs prescribed. Further evaluation included treadmill stress test, angiographic study, or thallium treadmill stress test if the patient refused angiography. Graft patency was evaluated with reference to occlusion (the graft could not be seen) and threadlike arteries, orstring signs (the graft was patent but had a diameter of less than 1 mm). Complete patency meant that there was no stenosis of the CAR and that the diameter of the ITA was superior to the diameter of the native artery. The presence of threadlike arteries (string signs) has been considered graft failure. Statistical analysis was done with the Student-Fisher test and chi 2 test. Results Weaning from cardiopulmonary bypass was difficult in 12 patients (11.1%). The perioperative mortality rate was 3.7% (4 patients). Perioperative complications included the following: MI, 7 (6.7%) of 104 patients; low cardiac output, 2; pulmonary infections, 8 (7.7%); mediastinitis, 3 (2.9%); phrenic nerve paralysis with good outcome, 2; stroke, 5 (4.8%), three of which were transient; and renal failure, 3 (2.9%). Seventy-six patients were free from complications (73.1%). Follow-up at a mean of months included 102 patients (98.1%); 2 patients were lost to follow-up. Three patients (2.9%) were in congestive heart failure but without angina; 1 of them underwent heart transplantation. During follow-up, 1 patient (1.0%) died of stroke. Of the other 98 patients, 3 (3.1%) had New York Heart Association Class II angina, and 5 patients (5.1%) had an MI in the posterior area. Ninety patients were free from angina and cardiac-related events (91.8%). Twenty-six patients (26.5%) required no medical treatment postoperatively; 58 patients (59.2%) were on a regimen of one antianginal drug; 12 patients (12.2%), two antianginal drugs; and 2 patients (2.0%), three antianginal drugs. The average number of antianginal drugs per patient (0.9) was lower after the operation ( p 0.01). A Treadmill stress test was performed by 79 patients (80.6%). Nineteen patients were not able to do this test because of other medical problems. The test results were negative for 48 patients (60.8%), positive for 8 (10.1%), and equivocal for 23 (29.1%). Sixty-eight patients (67.3%) with 74 CARs underwent control angiography at a mean of 29 months after operation. Angiography was contraindicated in 14 patients (14.3%) because of anaphylactic shock in 1, bilateral hip prosthesis with sepsis in 1, cancer in 2, stroke in 2, and amyotrophic lateral sclerosis in 1. Twenty-two patients refused control angiography; they were angina free. A thallium stress test was available for 16 of these 22 patients. There was one uptake defect in a nongrafted area, one in a CAR area, and one in a venous graft area. Angiographic results were as follows: ventricular dilatation in 6 patients (versus 9 before operation); akinetic ventricular segment in 33 patients (49% versus 81% before operation); and an ejection fraction lower than 0.5 in 5 patients (7% versus 19% before operation). Mean ejection fraction was 0.69 postoperatively versus 0.65 preoperatively ( p 0.05). One hundred forty-two coronary bypass grafts were controlled angiographically. Of the ITA grafts, 95% (n 113) were completely patent. Four (4%) had threadlike arteries (string signs) and two (2%) occlusions. Of the vein grafts, 56% (n 13) had complete patency. There were five diseased vein grafts (22%) and 5 vein graft occlusions (22%). The rate of complete patency was better with ITA grafts than with vein grafts ( p 0.05). Seventy-four CARs (62.7%) were controlled angiographically: the rate of complete patency was 94.6% (70 procedures; string signs and occlusion were present in two ITAs (2.7%) each. The rate of complete patency of the

4 1544 BARRA ET AL Ann Thorac Surg CORONARY RECONSTRUCTION FOR EXTENSIVE DISEASE 2000;70: Table 2. Patency of 74 Coronary Artery Reconstructions at Angiographic Follow-up at an Average of 29 Months Postoperatively a CAR ITA in CAR was the same as the rate for the ITA without CAR: 94.6% versus 94.9% ( p 0.05). Patency of CAR with reference to length of the reconstruction (short and long) and association with endarterectomy is shown in Table 2. Comment Complete Patency Threadlike Artery Occlusion Short (n 45) 41 (91.1) 2 (4.4) 2 (4.4) Short endarterectomy 6 (100) 0 0 (n 6) Long (n 19) 19 (100) 0 0 Long endarterectomy (n 4) 4 (100) 0 0 a Numbers in parentheses are percentages. CAR coronary artery reconstruction; 4 cm; short CAR shorter than 4 cm. long CAR longer than In this series, the indication for CAR was based on preoperative angiographic findings in 25% of the patients. In 56% of the study group, severe and extensive lesions were discovered during operation and necessitated CAR. Currently, more patients are scheduled for CAR before operation because cardiologists are aware of the possibilities of the technique. Noncalcified atheromatous plaques are excluded from the lumen of the reconstructed vessel, which prolongs the aortic cross-clamp time. However, modern cardioplegia allows complex and long procedures. Theoretically, the growth of these excluded plaques should stop. Calcified plaques were endarterectomized, but we performed limited endarterectomy to decrease the risk of postoperative myofibrointimal proliferation. Myofibrointimal proliferation remains a major risk of endarterectomy [11, 12]. It has been shown that an incomplete endothelial covering of the endarterectomized arterial wall enhances myofibrocyte proliferation, and in turn, this proliferation slows endothelial cell growth [13, 14]. On the contrary myofibrointimal proliferation is stopped when the endothelial covering is complete [15]. With our technique, 75% of the endarterectomized coronary artery wall is excluded from the reconstructed coronary lumen. As the endarterectomized area is reduced, complete endothelial covering must be achieved rapidly and thus should decrease the risk of a long period of intimal proliferation. This could explain our low rate of cardiacrelated events (no restenosis, few MIs) 29 months after operation. The operative mortality rate in our series is similar to the 2.5% to 10% rate in other series involving coronary operation for diffuse disease [6 8, 10]. The mortality associated with CAR is slightly higher than that we [16, 17] reported for classic coronary operations for nondiffuse disease, but the morbidity including MIs is the same [16]. Myocardial revascularization has been advocated to delay or avoid heart transplantation [18]. The survival rate of patients with diffuse coronary artery disease is 80% to 90% at 1 year and 40% to 80% at 5 years [19]. In our series 2 patients were lost to follow-up, and there were no cardiac-related deaths among the patients in follow-up. Their quality of life has been improved; 92% of the patients are free from angina, and the number of antianginal drugs per patient has been significantly lowered. Only 10% of postoperative treadmill stress tests were positive. Five patients sustained an MI in a nongrafted posterior area. These good clinical results were confirmed by postoperative coronary angiography at 29 months. In the literature, the patency rate at 1 year of the vein graft associated with endarterectomy is between 56% and 90% [6 8]. When an ITA is anastomosed to the vein patch, the patency rate is increased, ranging between 81% and 98% [10]. In our study, the rate of complete patency of the ITA in CAR with or without endarterectomy is 94.6%. It is difficult to compare our study with other reports because threadlike arteries are considered graft failure in our study, whereas this is not always the case in reported series. The ITA patency in our series is similar to the patency of classic ITA bypass grafts on nondiffuse coronary artery lesions [2, 4, 16]. Coronary artery reconstruction does not increase the rate of ITA graft failure despite diffuse coronary lesions. Some atheromatous plaques are very fragile, with a lipid nucleus and a low level of fibrosis. These plaques cannot cause major stenosis of the coronary vessel, but the risk of plaque rupture remains great. Such rupture is the major cause of vascular thrombosis, unstable angina, and MI [20]. It is possible that the exclusion of this kind of plaque explains the low incidence of MI and cardiacrelated events at 2 years in our series. In this series of 108 patients, CAR allowed safe coronary revascularization in patients with diffuse and extensive disease and produced good results. Exclusion of atheromatous plaques from the lumen of the reconstructed vessel may delay the evolution of the plaques, and limited endarterectomy with exclusion of the endarterectomized arterial wall may decrease the rate of postoperative myofibrointimal proliferation and restenosis. Our encouraging results confirm this hypothesis, but longer follow-up is needed. The technique of CAR provides a surgical option for patients with diseased vessels that cannot be treated by percutaneous transluminal coronary angioplasty or conventional CABG. References 1. Myers WO, Schaff HV, Gersh BJ, et al. Improved survival of surgically treated patients with triple vessel coronary artery disease and severe angina pectoris. A report from the Coronary Artery Surgery Study (CASS) registry. J Thorac Cardiovasc Surg 1989;97: Zeff RH, Kongtahworn C, Iannone LA, et al. Internal mammary artery versus saphenous vein graft to the left anterior

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