Expanding the use of the internal mammary artery to improve patency in coronary artery bypass grafting

To improve the early and late benefits from coronary artery bypass grafting, we have expanded the use of the internal mammary artery by bypassing three or more coronary arteries with mammary grafts. Experience with higher power magnification and the use of the single internal mammary artery are necessary prerequisites of this procedure. The first 100 patients who had three or more mammary artery-coronary artery anastomoses are reviewed. Eighty-six patients received three mammary-coronary anastomoses, 13 received four, and one received six. An average of 3.2 internal mammary artery grafts and 1.7 saphenous vein grafts per patient were placed. Twenty-five of 27 mammary grafts were open on postoperative graft visualization. There were no early deaths and only one patient died late of complications of gangrene of the lower extremities. None of the patients had significant left ventricular failure and only three had perioperative myocardial infarctions. None of the patients complain of angina and 58 of 59 postoperative stress tests were normal. This procedure should significantly reduce the late closure of bypass grafts and the complications thereof, including the need for reoperation.     

Coronary bypass surgery for solitary stenosis of the left main coronary artery

Ten patients with solitary stenosis of the left main coronary artery underwent coronary artery bypass grafting. All patients suffered from unstable angina and were in NYHA class III or IV. Two of them required intravenous infusion of nitroglycerin preoperatively. The degree of stenosis of the left main coronary artery was 75% in 3 patients, 90% in 5, 95% in one and total obstruction in the other one. Five patients received saphenous vein grafts to the LAD and circumflex artery and the other 5 patients received IMA grafts to the LAD and saphenous vein grafts to the circumflex arteries. In 2 patients with 75% stenosis of the left main coronary artery we found narrow internal mammary artery grafts, the so called "string sign", on postoperative angiography. Although several causes of string sign were proposed previously, we supposed that the main cause of the "string sign" was the competition for flow between the IMA graft and the native coronary artery or grafted coronary artery. Postoperatively, all patients showed improvements in cardiac function and were in NYHA class I. No evidence of ischemic findings was found in postoperative exercise stress tests.     

Reoperation for myocardial revascularization using the internal mammary artery

From October 1984 up to February 1989, 40 patients had "redo" myocardial revascularizations using one or both internal mammary arteries (IMA) in over 1000 cases operated upon in our Department for coronary bypass grafts. Thirty-one patients had a further operation for unstable angina difficult to control with drugs. Mean interval of recurrence of angina after previous surgery was 48.5 months for all the cases, but the mean interval before the second bypass operation was 68 months. Severe disease of previous vein grafts was the reason for surgery in 25 patients and progressive atherosclerosis in native coronary arteries in 15 patients. Twenty-one patients had a single mammary artery; both mammary arteries were used in 19. Two cases had endarterectomy on left anterior descending (LAD). Four patients had peroperative acute myocardial infarction (AMI), 3 a low cardiac output syndrome, postoperative bleeding occurred in 3 cases and wound infection in one case. An intraaortic balloon pump was used preoperatively in one case and coming off bypass in two others. One patient died on the second day postoperatively from cardiac arrest following bilateral pneumothorax. There were no late deaths. At a mean follow-up of 20.5 months, 28 patients are free of symptoms but 11 are complaining of angina, 5 during exercise and 6 at rest. An exercise test was positive in 8 patients.     

Use of the inferior epigastric artery for coronary bypass.

Between December 1988 and April 1991, 74 free inferior epigastric arteries were used in 73 patients for coronary artery bypass grafts. In addition, 72 of the patients received a left internal mammary artery for single or sequential grafting to the left anterior descending system and 62 a right internal mammary artery to the circumflex or the right coronary artery. Twenty-seven patients had no saphenous vein available, and two had no suitable internal mammary artery; in an attempt to make a complete arterial revascularization, we chose the inferior epigastric artery as an alternative conduit in 24 young patients and in 10 reoperations; bilateral internal mammary artery dissection was avoided in four patients with impaired lung function and in six patients with selected two-vessel disease to spare one internal mammary artery. The technique for harvesting the inferior epigastric artery is described. Fifty-three inferior epigastric artery grafts were anastomosed to the distal right coronary artery or to its branches, 18 to the distal obtuse marginals of the circumflex artery (three as sequential grafts and one as a natural Y graft), and three to the left anterior descending system. The mean number of distal anastomoses is 3.60 per patient. Seventy proximal anastomoses of the inferior epigastric artery were made to the aorta and four to one internal mammary artery. There were four early deaths and one nonfatal myocardial infarction. Four abdominal wound hematomas needed surgical drainage. Sixty-one patients underwent angiographic study on postoperative day 10:59 of 61 inferior epigastric artery grafts (63 of 65 inferior epigastric artery distal anatomoses) and 111 of 111 internal mammary artery grafts (155 of 156 internal mammary artery distal anastomoses) were patent. Clinical follow-up of all the survivors (100% follow-up) could be obtained with a mean period of 9 months (1 to 28 months). There was no late cardiac death, no infarction, and all the patients were free of angina. Nineteen patients underwent a 6-month postoperative angiographic study. Seventeen of 19 inferior epigastric artery grafts were patent and 16 of 19 were intact; 34 of 34 internal mammary artery grafts (46 of 47 internal mammary artery distal anastomoses) were patent and intact. In conclusion, free inferior epigastric artery grafts can reach the diaphragmatic ischemic areas of the heart. The early patency rate and the clinical results are encouraging but only long-term evolution and evaluation can determine the true efficacy of the inferior epigastric artery graft as a reliable conduit for coronary artery bypass graft operations.     

Expanded use of internal mammary artery graft for myocardial revascularization

To improve the early and late benefits of coronary artery bypass grafting, use of internal mammary artery grafts was expanded. The first 60 patients to receive two mammary artery-coronary artery anastomoses and supplemental saphenous vein grafts are reviewed. Altogether 210 grafts (3.5/patient) were performed, including 54 mammary artery grafts in situ, six of them as free grafts. In 12 patients the right internal mammary artery was placed through the transverse sinus to revascularize the circumflex artery, and the left mammary artery was placed to the left anterior descending artery. In the remaining 48 patients both internal mammary arteries were used to revascularize the left anterior descending and the right coronary artery. There were no perioperative deaths and no sternal infections. Postoperative complications included re-exploration for bleeding and diaphragmatic dysfunction. Late follow-up was complete. Of 60 patients observed for 1/2 to 4 years, 57 were asymptomatic. Exercise stress tests were performed in 58 cases and were normal in 56.     

Coronary artery bypass grafting with the right gastroepiploic artery

The excellent results of coronary artery bypass with the internal mammary artery and the increasing numbers of patients who need coronary reoperations, but for whom conventional bypass conduits are not available, have prompted us to evaluate alternative arterial bypass conduits. The right gastroepiploic artery has been used as a coronary bypass graft in 36 patients (32 men), whose ages ranged from 29 to 71 years. Twenty-two patients had had previous coronary bypass grafting and six of these were undergoing their third bypass operation. The right gastroepiploic artery was used as an in situ graft to the right coronary artery or circumflex branches for 17 patients and as an aorta-coronary ("free") graft in 19 patients, six to the left anterior descending or diagonal, six to the circumflex, and seven to the right coronary artery. In conjunction with right gastroepiploic artery grafting, 16 patients received bilateral internal mammary artery grafts and 17 received one internal mammary artery graft. Histologically, right gastroepiploic artery segments from 18 patients could not be distinguished from internal mammary artery segments, and no evidence of atherosclerosis was found. Two patients died in the hospital, one intraoperatively and one 3 months after the operation, of a perioperative stroke. Perioperative morbidity included wound complication in three and reexploration for bleeding in two. At late follow-up 1 to 38 months after operation, two late deaths had occurred and 21 patients were free of symptoms. Postoperative angiography (postoperative interval 1 week to 13 months) was performed in nine grafts, three in situ grafts to the right coronary artery and six free grafts that included two to the left anterior descending, three to the circumflex, and one to the right coronary artery. All right gastroepiploic artery grafts were patient. The right gastroepiploic artery is an arterial conduit that can be used as an in situ graft to posterior coronary vessels and as a free graft to any coronary arterial system. Early graft patency has been excellent, and the histologic similarity between the right gastroepiploic artery and the internal mammary artery suggest that the long-term results will be favorable.     

微创冠状动脉搭桥术(附23例报告)

目的　探索冠状动脉搭桥术的微创治疗方法。　方法 1999年 1月至 2 0 0 0年 8月 ,用Octo pus方法给 2 3位冠状动脉狭窄的患者行冠状动脉搭桥术。搭桥数 1根 1例 ,2根 3例 ,3根以 19例。移植部位 :前降支 2 3例 ,对角支 8例 ,回旋 15例 ,右冠 14例 ,后降支 8例。移植血管 :左乳内动脉 2 0根 ,大隐静脉 4 8根。　结果　无手术死亡 ,无中转体外循环 ,术后心绞痛消失 ,MRI提示桥血管通畅。　结论　非体外循环下冠状动脉搭桥术适用于多支血管病变 ,包括回旋支和后降支。桥血管通畅率与常规冠状动脉搭桥术相同。并发症少 ,费用低 ,是一种安全、经济的微创手术方法。     

Use of gastroepiploic and internal mammary arteries for myocardial revascularization

Triple coronary artery bypass grafting utilizing the right gastroepiploic artery and both internal mammary arteries was performed successfully in a 37-year-old male, achieving primary myocardial revascularization. All grafts were in situ. The right gastroepiploic artery was anastomosed to the posterior descending artery. The right and left internal mammary arteries were anastomosed to the left anterior descending artery and the posterolateral branch, respectively. The postoperative angiogram showed good patency of all grafts. The patient recovered uneventfully with resolution of his angina pectoris.     

Right gastroepiploic artery as a coronary bypass graft

Between November 1987 and April 1988, the right gastroepiploic artery (GEA) was used as a coronary artery bypass graft in 11 patients, 9 men and 2 women. In 1 of them, the GEA was used because no veins were available; in the others, the GEA was used to avoid the use of vein grafts. The GEA was anastomosed to the right coronary artery in all patients, and internal mammary artery grafts were used to bypass the left anterior descending and circumflex coronary arteries. All patients survived the operation. There were no early and, to date, there have been no late complications of the abdominal component of the operation. Postoperative coronary angiography showed a patent right GEA in 9 patients (82%). In 1 patient the GEA was occluded, probably because of an enlarged liver. If the long-term patency of right GEA grafts is similar to that of internal mammary artery grafts, wider use of this viable graft is indicated.     

Myocardial revascularization with three native in situ arteries. Gastroepiploic and bilateral internal mammary artery grafting

Three native arteries were used for coronary artery bypass grafting in six patients in whom complete revascularization was not feasible because of varices or previous venous stripping. The right gastroepiploic and both internal mammary arteries were placed as pedicled conduits, and four patients additionally received a total of six vein grafts available from the greater or lesser saphenous system. Surgical complications were minimal and complete relief from angina was obtained in all patients, even in maximal stress testing. All 24 grafts were angiographically checked: 23 (96%) were patent and one gastroepiploic artery was occluded. All patients had at least three patent grafts. These native arteries are excellent conduits when suitable veins are not available. They should also be used on individual indications to replace occluded grafts.     

Clinical experience of bovine internal mammary artery graft (BIOFLOW) for coronary artery bypass surgery

Bovine internal mammary artery graft (BIOFLOW: BIOVASCULAR INC. Netherlands) has been used for coronary artery bypass grafting (CABG) in 8 patients since May 1988 at Osaka Medical College Hospital. There were 4 males and 4 females. Mean age was 66.9 year-old ranged from 62 to 72. Two were emergency CABG and other six had inadequate saphenous veins. The internal mammary artery and/or the saphenous vein were concomitantly used in all patients. Number of grafts was 2 to 6 with the mean of 2.9 and BIOFLOW (phi 3 mm) was anastomosed to 2 left anterior descending arteries and 6 right coronary arteries, the mean graft flow of BIOFLOW was 72.5 ml/min ranged from 52 to 120 ml/min. One patient died of ventricular arrhythmia on 5 postoperative day. There was no new Q wave infarction. Postoperative angiogram within 2 months showed 4 of 5 BIOFLOW grafts were patent, and no stenosis was found in those patent grafts. All survivors returned to home with a freedom from angina. From our experience, although the number was small and the follow-up period was short, BIOFLOW can be expected as an conduit of choice for CABG when the saphenous vein was not available and the internal mammary artery and the gastroepiploic artery were not enough to accomplish the complete revascularization.     

Clinical and angiographic assessment of complex mammary artery bypass grafting

The internal mammary artery has become the coronary bypass graft of choice in recent years because of enhanced long-term patency. Along with this trend, sequential, bilateral, and free mammary grafts have been employed more frequently in an effort to maximize the number of distal internal mammary anastomoses. This approach of maximally using the internal mammary artery (complex mammary grafting) seems logical, but at present little information about patency of the newer types of internal mammary artery grafts is available to justify the more complicated procedures. Over a 15 month period, 207 patients underwent bypass graft angiography from 1 to 32 weeks after operation. This is an 85% restudy rate for a consecutive series of coronary bypass procedures. Patency was defined as complete filling of the graft and distal vessel bypassed. A total of 841 distal vessels were grafted, or 4.1 per patient. The overall patency rate was 91% for 503 distal vein graft anastomoses and 99% for 338 internal mammary artery grafts. Individual patency rates of distal anastomoses, expressed as number patent/total (percent patent), were as follows: simple vein grafts, 262/285 (92%); sequential vein grafts, 196/218 (90%); left internal mammary artery to left anterior descending coronary artery, 109/110 (99%); left internal mammary to circumflex marginal artery, 14/14 (100%); right internal mammary to right coronary artery, 19/20 (95%); right internal mammary to left anterior descending coronary artery, 10/10 (100%); right internal mammary to circumflex marginal artery via transverse sinus, 18/20 (90%); sequential left internal mammary artery to left anterior descending system, 133/134 (99%); sequential left internal mammary to circumflex marginal system, 15/15 (100%); free internal mammary artery, 9/9 (100%); free sequential internal mammary artery, 6/6 (100%). Of the 18 patent transverse sinus right internal mammary grafts to the circumflex marginal artery, three exhibited very slow flow and probably were not functional. The hospital mortality associated with internal mammary revascularizations was 0.4% for nonemergency cases and 3.1% for emergency procedures. On the basis of clinical and postoperative graft patency data, expanded use of more complicated types of mammary grafts seems justified. Function of the right internal mammary graft to the circumflex marginal artery was suboptimal, and this method has been discontinued. All other complex mammary techniques had excellent patency rates as compared to vein grafts, and these differences may become even more significant in the late postoperative period.(ABSTRACT TRUNCATED AT 400 WORDS)     

Off-pump coronary bypass using interposed radial artery graft

We describe a patient with severely diseased ascending aorta and small internal mammary arteries, who underwent off-pump coronary artery bypass to the left anterior descending coronary artery and right coronary artery using composite arterial grafts consisting of the pedicled proximal internal mammary artery and interposed radial artery graft. The interposed radial artery graft provides advantages, such as making coronary anastomosis on the beating heart easier and to increasing the flow potentiality of the internal mammary artery.     

Surgical implications of anomalous aortic origin of the left coronary artery

We report a patient with exertional chest pain and anomalous aortic origin of the left coronary artery from the right coronary sinus. This patient also had circumflex coronary and right coronary artery stenoses. Following coronary bypass grafting of the circumflex and right coronary arteries in this patient, angina persisted and there was abnormal septal perfusion shown on the exercise thallium imaging despite patent grafts. The angina and perfusion defect were improved by bypass grafting of the unstenosed left anterior descending coronary artery in this patient. Thallium imaging may be useful in the preoperative assessment of patients with this anomaly.     

Bilateral internal mammary artery grafts for coronary artery bypass operations in children

We performed myocardial revascularization with bilateral internal mammary arteries in eight children for coronary artery complications consequent to Kawasaki disease. Subjects included seven boys and one girl, ranging in age from 3 to 13 years (mean age, 8.3 +/- 3.4 years). The body surface area ranged from 0.65 to 1.65 m2 (average, 1.08 +/- 0.35 m2). Three patients had a previous myocardial infarction. The right internal mammary artery was anastomosed to the right coronary artery and the left internal mammary artery was sutured to the left anterior descending artery in all patients. The patients received an average of 2.4 grafts. Magnifying loupes of 3.5 X were used for anastomosis with 8-0 monofilament polypropylene sutures. Subjects were followed up from 12 to 38 months (23 +/- 10.8 months) after operation. All were doing well with no recurrence of angina, and body development was normal, including the sternum and thorax according to chest x-ray films and computed tomography of the chest. Patency of the bilateral internal mammary arteries was 100% in the early (within 1 month) postoperative period and remained so in the late (over 1 year) postoperative period. Anastomotic junctions between the internal mammary artery and the coronary artery developed well angiographically in the late postoperative period. The internal mammary artery is the graft of choice for pediatric myocardial revascularization because of its excellent long-term patency and growth potential. Bilateral internal mammary arteries should be used whenever indicated, and the use of bilateral internal mammary arteries did not adversely influence chest wall development in the children.     

Bypass of the right and circumflex coronary arteries with the internal mammary artery.

Our experience with the internal mammary artery (IMA) for coronary bypass grafting in the past 3 years includes 323 grafts in 253 patients. After an initial group of IMA to left anterior descending (LAD) coronary artery grafts, we began using the IMA to bypass circumflex and small right coronary arteries (RCA). This report describes our experience with IMA bypass of coronary vessels other than the LAD. A total of 96 patients have had an IMA graft to the circumflex or RCA. Most of these patients had two or more bypasses. The mortality rate for this group has been 7 per cent, 7 of 96 patients. Postoperative angiography in 82 of 89 survivors has shown a patency rate of 98 per cent in 83 of 85 grafts studied. We conclude that the IMA is the vessel of choice for coronary artery bypass and that it can be used to bypass any of the main coronary arteries.     

Long-term blood flow potentials in sequential internal mammary artery grafts. Exercise thallium scan for myocardial perfusion study.

In two groups of patients, coronary artery bypass surgery for angina pectoris included internal mammary artery (IMA) sequential grafts (group I) or single grafts (group II). At postoperative angiography all grafts were patent. In addition, the patients received on average 1.8 vein grafts into other coronary arteries. The mean interval to postoperative follow-up was 9.5 years in group I and 9.7 years in group II. The preoperative incidence of acute myocardial infarction was 44% and 45% in groups I and II. Exercise thallium scan at follow-up showed IMA graft-related ischemia in 33% of the patients with sequential graft and in 64% of those with single graft (ns). Our results indicated that sequential IMA grafts functioned at least as well as single grafts and maintained adequate myocardial supply even 10 years postoperatively. Internal mammary arteries are superior graft material and can be recommended both as single and as sequential graft in coronary artery bypass surgery.     

Simultaneous coronary artery bypass grafting and ascending aorta bifemoral bypass in small aorta syndrome.

A 55-year-old man with severe coronary artery disease and aortoiliac occlusive disease with small aorta syndrome was admitted to our department with angina pectoris and bilateral claudication. Intravenous subtraction angiography showed total occlusion of the right common iliac artery and 99% stenosis of the left common iliac artery with a markedly hypoplastic infrarenal aorta only 9 mm in diameter. It also revealed 90% stenosis at the origin of the left subclavian artery. Coronary angiography showed total occlusion of the left anterior descending artery and 90% stenosis of the circumflex artery. Simultaneous coronary artery bypass grafting and an ascending aorta-bifemoral bypass were conducted using an in-situ right internal mammary artery graft, an autologous saphenous vein graft, and a Y-figured expanded polytetrafluoroethylene graft. Postoperative angiography showed grafts to the coronary and bifemoral arteries were patient. This combined procedure is useful for patients with coronary artery disease and aortoiliac occlusive disease, especially in those with small aorta syndrome.     

Internal mammary artery bypass graft--long-term patency rate and follow-up

Between December, 1968, and January, 1974, 814 internal mammary artery and 351 saphenous vein bypass graft procedures were performed in 628 patients. Operative mortality during the past 3 years has been 1.7%. Internal mammary artery bypasses were performed to the anterior descending, circumflex, obtuse marginal, distal right, and posterior descending right coronary arteries. Ninety-one patients having 137 internal mammary artery and 32 saphenous vein grafts were studied angiographically 12 to 36 months postoperatively. All but 2 internal mammary artery bypasses were patent, a patency rate of 98.5%; 27 of the 32 saphenous vein bypasses in this group were patent (84.3%). The majority of the internal mammary artery bypasses were to distal coronary arteries, while the saphenous veins were used primarily for proximal anastomosis. Cineangiographic volume/flow studies were also performed. The average flow in the more distal internal mammary artery bypasses was 61 ml. per minute as compared with 91 ml. per minute in the proximal saphenous vein grafts.     

非体外循环下双侧乳内动脉Y型桥的冠状动脉旁路移植术125例

目的总结非体外循环下采用双侧乳内动脉Y型桥进行完全心肌血运重建的冠状动脉旁路移植手术125例的近期疗效。方法2002年10月至2005年12月,完成125例不停跳非体外循环下双侧乳内动脉Y型桥的冠状动脉旁路移植手术,术中采用带蒂半骨骼化的方法分别取材左、右侧的乳内动脉,将左、右乳内动脉端侧吻合成Y型桥;在非体外循环下,应用序贯吻合的方法进行冠状动脉搭桥手术。结果全组125例患者共搭桥413支,平均搭桥支数3．3支／例。术中流量测定桥血管均通畅。全组患者无围手术期死亡。结论非体外循环下双乳内动脉Y型桥的冠状动脉旁路移植手术是安全、有效的方法,可以实现全动脉化的完全心肌血运重建,又避免手术中对升主动脉的操作,近期效果满意。