A case of coronary artery bypass utilizing natural bifurcation of the right internal mammary artery

A Forty five year old male with unstable angina due to multiple coronary artery stenosis underwent successful complete coronary revascularization utilizing the natural bifurcation of the right internal mammary artery. As this procedure has not been reported in detail previously in the literature and since the use of the natural bifurcation of the internal mammary artery was considered to be useful for the treatment of multiple coronary stenosis, this case was presented. Pre and post operative angiography is included.     

Free internal mammary artery for coronary bypass

We studied 12 cases of free internal mammary artery (IMA) grafting. We used IMAs as free grafts mainly because of its shortness (6 cases 50%) and injury during dissection (4 cases 33%) and found the varicose change of saphenous vein in 5 cases (42%). Most of the grafting sites are distal parts of coronary arteries. Proximal anastomosis sites are other vein grafts (3 cases), other IMA grafts (3 cases), vein grafts interposing to the aorta (3 cases), and aorta (1 case). Patency rate of the free IMA grafts 4 weeks after operations was good (82%). Free IMA grafting is safe alternative to in situ IMA grafting when IMA grafts are short or injured and saphenous vein grafting is impossible.     

Free internal mammary artery for coronary bypass.

An improved technique of free internal mammary artery (IMA) to ascending aorta anastomosis for coronary bypass is described. A small patch vein with a suitable side branch or branches is interposed, connecting the proximal end of a detached IMA to the ascending aorta. A single or double free IMA alone or in combination with an additional saphenous vein graft was performed in 77 patients. A total of 125 free IMA grafts were done. The hospital mortality was 2-7% and late mortality 1-4%. Seventy-one of the 74 surviving patients had no angina and returned to a normal life. Postoperative coronary arteriography in 65 patients showed a patency rate of 96%. On year's experience with this technique is very encouraging. However, prolonged follow-up is necessary to determine if free IMA, as used by us, will increase the long-term patency rate.     

Twelve-year experience with internal mammary artery for coronary artery bypass

From Feb. 1, 1972, to Jan. 30, 1984, 1,000 patients had isolated coronary bypass with at least one internal mammary artery, and 103 of them had bilateral internal mammary artery grafts. There were 1,395 associated vein grafts and 1,158 internal mammary artery anastomoses, for a total of 2,556 grafts (2.5 per patient). Patients were followed up for 1 to 12 years (mean 6.3 years) and 77 patients were lost to follow-up at a mean of 4.0 years. Operative mortality was 1.4%, with 11 of 14 deaths in the first 240 patients (4.6%) and eight of 14 in the 103 patients with bilateral internal mammary artery grafts. There were 93 late deaths, with an actuarial survival rate of 93% at 5 years and 84% at 10 years. Angina occurred at a mean rate of 6.2% +/- 1.2% per year. Perioperative infarction was detected in 37 patients (3.7%). Late infarction occurred in 75 patients, for a mean rate of 1.5% +/- 0.3% per year. Reoperation (or percutaneous transluminal coronary angioplasty) was necessary in 35 patients, for a mean rate of 0.85% +/- 0.28% per year. Graft patency was assessed by 1,029 follow-up catheterizations in 519 patients. The patency rate of the left internal mammary artery was 96.4% at 1 year, 88.1% at 5 years, and 88.1% at 10 years. That of the right internal mammary artery was 92.8% (p = NS) at 1 year, 84.6% (p = NS) at 5 years, and at 10 years the numbers were too small to be meaningful. Comparison of patency rates for all internal mammary artery grafts with vein grafts gave 1 year graft patency rates of 95.7% versus 93.4% (p less than 0.025), 5 year rates of 87.9% versus 74.0% (p less than 0.001), and 10 year rates of 83.0% versus 41.0% (p less than 0.001). Included in these patency data are 20 free internal mammary artery grafts; 16 were studied (mean 2.3 years) and 12 of these 16 (75%) were patent. Of the 58 sequential internal mammary artery grafts, 18 were studied by catheterization (mean interval 2.0 years); 35 of 36 anastomoses were patent and one end-to-side anastomosis was closed. Morbidity and mortality for patients having internal mammary artery grafting are comparable to those of patients having saphenous vein bypass only. The demonstrated superior patency for internal mammary artery grafts supports the routine use of bilateral internal mammary artery grafting.     

Sequential internal mammary-coronary artery bypass

A total of ten patients have undergone sequential bypass grafting of the internal mammary artery (IMA) to the coronary arteries at Osaka Medical College. Operative procedures included left IMA bypass to the left anterior descending (LAD) artery and its major diagonal branch in six patients; to the obtuse marginal branch and diagonal branch in three patients; and to the first and the second diagonal branches in one patient. The right internal mammary artery was concomitantly utilized in 4 patients and saphenous vein graft was also utilized in 6 patients. Postoperative angiographic studies were performed in nine patients within 6 months after operation and in all 18 sites of IMA anastomoses, the IMA sequential grafts were patent. Since sequential IMA-coronary bypass technique means the increase of arterial graft, we believe that this technique should be used for multivessel coronary revascularization especially in younger patients.     

Sequential internal mammary-coronary artery bypass

Since April, 1977, a total of eight patients have undergone sequential bypass grafting of the internal mammary artery (IMA) to the coronary arteries at our institution. The indication for this newly described procedure was either insufficient supply of adequate veins (four patients) or the presence of a diseased aortic wall (two patients). Operative procedures included left IMA bypass to the left anterior descending (LAD) artery and its major diagonal branch in six patients; to the obtuse marginal branch and distal circumflex artery in one patient; and to two consecutive sites on the LAD in one patient. All patients became angina-free after operation for a follow-up period lasting up to 6 years. Recatheterization studies were performed in four patients, in all of whom the IMA sequential grafts were found patent. We believe that IMA sequential grafting is an important option available to the cardiac surgeon in managing some patients with coronary artery disease.     

Breast necrosis following use of the internal mammary artery for coronary artery bypass

Coronary artery bypass grafting is a common surgical procedure for myocardial revascularization. This operation usually involves the use of the left internal mammary artery to bypass the left anterior descending coronary artery. The internal mammary artery and its perforators are also an important blood supply to the female breast, though not considered a critical blood supply. Due to an abundant blood supply from multiple sources, complications of the female breast are rare. We present a case report of a patient who developed necrosis of the entire medial left breast and superior abdominal wall following coronary artery bypass grafting which used the left internal mammary artery.     

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.     

全机器人胸廓内动脉游离非体外循环冠状动脉旁路移植术

目的总结全机器人下不开胸胸廓内动脉（IMA）游离心脏不停跳冠状动脉旁路移植术的初步经验。方法使用da Vinci S全机器人系统,完成胸廓内动脉游离心脏不停跳下冠状动脉旁路移植术15例。所有患者均有心绞痛症状,其中4例患者有心肌梗死病史,冠状动脉造影显示严重的前降支病变,2例患者对角支及回旋支亦有病变。手术过程中于左侧胸壁打直径为1cm的器械臂孔3个,医生于操作台前在三维成像系统下操控机器人进行胸廓内动脉的游离,其中13例行左侧胸廓内动脉游离,1例行双侧胸廓内动脉游离,1例行对侧胸廓内动脉游离。游离结束后,沿左胸前第4肋间行长度为6cm小切口开胸,13例于心脏跳动下行胸廓内动脉和前降支的吻合,2例同时吻合对角支或回旋支。其中1例是完全机器人不停跳下冠状动脉旁路移植术。结果所有患者均成功接受胸廓内动脉游离,无胸廓内动脉损伤及术式的转变。胸廓内动脉和前降支、对角支和回旋支吻合后桥血流良好。术中平均出血量80ml,平均ICU时间20h,术后恢复好。结论全机器人不开胸胸廓内动脉游离技术精细、安全,不停跳下冠状动脉移植术效果确实、可靠,术后效果良好。     

Coronary-coronary bypass using internal mammary artery

A free right internal mammary artery was used to bypass the right coronary artery in a patient with no available saphenous vein. The proximal end of the right internal mammary artery was anastomosed to the proximal right coronary artery, and the distal end of the free graft was anastomosed to the posterior descending coronary artery. Coronary-coronary bypass using a free internal mammary artery is an attractive approach to bypassing very distal vessels when other conventional grafting techniques are not possible.     

Dopexamine increases internal mammary artery blood flow following coronary artery bypass grafting.

OBJECTIVE: Vasoactive agents and inotropes influence conduit-coronary blood flow following coronary artery bypass grafting (CABG). It was hypothesized that dopexamine hydrochloride, a dopamine A-1 (DA-1) and beta(2) agonist would increase conduit-coronary blood flow. A prospective randomized double blind clinical trial was carried out to test this hypothesis. DA-1 receptors have previously been localized to human left ventricle. METHODS: Twenty-six American Society of Anaesthesiology class 2-3 elective coronary artery bypass graft patients who did not require inotropic support on separation from cardiopulmonary bypass (CPB) were studied. According to a randomized allocation patients received either dopexamine (1 microg/kg per min) or placebo (saline) by intravenous infusion for 15 min. Immediately prior to and at 5,10 and 15 min of infusion, blood flow through the internal mammary and vein grafts (Transit time flow probes, Transonic Ltd.), heart rate, cardiac index, mean arterial pressure and pulmonary haemodynamics were noted. The data were analysed using multivariate analysis of variance. RESULTS: Low-dose dopexamine (1 microg/kg per min) caused a significant increase in mammary graft blood flow compared to placebo at 15 min of infusion (P=0.028, dopexamine group left internal mammary artery (LIMA) flow of 43.3+/-14.2 ml/min, placebo group LIMA flow at 26.1+/-16.3 ml/min). Dopexamine recipients demonstrated a non-significant trend to increased saphenous vein graft flow (P=0.059). Increased heart rate was the only haemodynamic change induced by dopexamine (P=0.004, dopexamine group at 85.2+/-9.6 beats/min and placebo group at 71.1+/-7.6 beats/min after 15 min of infusion). CONCLUSION: This study demonstrates that administration of dopexamine (1 microg/kg per min) was associated with a significant increase in internal mammary artery graft blood flow with mild increase in heart rate being the only haemodynamic change. Low-dose dopexamine may improve graft flow in the early post CABG period with minimal haemodynamic changes.     

Coronary artery bypass using bovine internal mammary artery

Among 760 patients who underwent coronary artery bypass graft (CABG) 8 received one or two bovine internal mammary artery grafts. The surgical procedures were 4, 3 and 3 CABG respectively in 1, 3 and 4 cases with greater saphenous veins in 4 cases, internal mammary artery in 4 cases and bovine internal mammary artery in 11 cases. The 3 mm bioflow grafts were used to revascularize the left coronary artery in 6 cases (to the left anterior descending, circumflex artery) and the right coronary artery in 5 cases. The indications for the use of bovine mammary artery grafts were lack of suitable autologous vessels because of bilateral saphenous vein stripping in 4 cases, bilateral varicose veins in 3 cases and inadequate length of vein in 1 case. Post-operative angiographic studies of these bovine mammary grafts with a maximum follow-up of 11 months showed 5 occluded grafts, 2 grafts with proximal stenosis, one graft which remained patent until the patient died and 3 grafts still under evaluation. Bovine internal mammary artery grafts provide a solution for the acute stage of coronary disease, but do not achieve total and durable revascularization. Their use must remain exceptional.