Congenital atresia of the left main coronary artery ostium--a case suffering from ventricular tachycardia

A case of congenital atresia of the left main coronary ostium suffering from ventricular tachycardia underwent coronary artery bypass operation. The patient was 17 years old boy. When he was 9 years old he visited our department for the purpose of examining cardiac disease. The diagnostic impression was mitral regurgitation. At 16 years old he suddenly complained tachycardia during exercise. He admitted to our hospital and the tachycardia was proved to be ventricular tachycardia. Left ventriculogram demonstrated a small range of akinesis at the left ventricular apex. And coronary cineangiogram revealed atresia of the left main coronary artery. The left coronary artery was perfused with collateral circulations from right coronary artery. Electrophysiological study was performed. The ventricular tachycardia could be reproducibly initiated and terminated by programmed stimulation. The catheter endocardial mapping was also performed. The source of ventricular tachycardia was supposed to be at the left ventricular apex. At 18 years old coronary artery bypass operation was performed. Internal mammary artery graft was placed to the left anterior descending artery and a saphenous vein graft was placed from the ascending aorta to the left circumflex artery. A small size of myocardial infarction was recognized at the left ventricular apex. And epicardial mapping revealed that the source of arrhythmia was the same region as the myocardial infarction was recognized. Endocardial resection or cryoablation was not performed. Post-operative study was performed 8 months after surgery. The graft flow of the internal mammary artery to the left anterior descending artery was not sufficient.(ABSTRACT TRUNCATED AT 250 WORDS)     

Atherosclerosis in type IV dual left anterior descending artery and anomalous aortic origin of the left circumflex artery in association with rheumatic valve disease: a case report

Double left anterior descending coronary artery arising from the left and right coronary arteries is a very rare congenital coronary artery anomaly. In this case, there was also a circumflex artery arising from the right sinus Valsalva and in association with severe rheumatic valve disease. Subsequently, the patient underwent mechanical aortic valve replacement with a 21-mm bileaflet mechanical aortic valve and coronary artery bypass grafting. We performed coronary artery bypass grafting of 3 vessels, including the left internal mammary artery to the large diagonal branch and the saphenous vein graft to the circumflex artery and the right coronary artery, under cardiopulmonary bypass. In this report, we describe an unusual case of this combination in association with both atherosclerosis and rheumatic aortic and mitral valve disease.     

Minimally invasive direct coronary artery bypass grafting using the saphenous vein in redo CABG.

We describe a patient who underwent minimally invasive direct coronary artery bypass (MIDCAB), who had previously undergone coronary artery bypass grafting (CABG) through a median sternotomy with a left internal mammary artery (LIMA) graft to the left anterior descending artery (LAD) and a right gastroepiploic artery (GEA) graft to the posterior descending artery. MIDCAB was less invasive and was an effective alternative procedure for the second operation. Because the patient had no LIMA or GEA available for a graft because of prior use, we used a saphenous vein graft (SVG) for bypassing from the left subclavian artery to the coronary artery by MIDCAB via a left minithoracotomy. The left subclavian artery was selected as the proximal anastomotic site because this artery was less diseased and was easier to reach. The SVG-to-coronary artery anastomosis was facilitated by firm adhesion between the epicardium and the pericardium, which reduced the motion of the epicardium itself. These results suggest that the procedure is safe and promising in selected cases of redo CABG.     

Expanding retrograde saphenous vein graft aneurysm treated with endovascular coiling

Saphenous vein graft aneurysm is a potentially fatal complication of coronary artery bypass grafting and usually requires surgery. This report describes endovascular coiling of a saphenous vein graft aneurysm that developed after redo coronary artery bypass grafting. The aneurysm occurred in a proximally occluded saphenous vein graft after revascularization of the same target vessel. The procedure required a retrograde approach through a patent left internal mammary and left anterior descending artery to reach and successfully thrombose the aneurysm.     

Evaluation of postoperative flow reserve in internal mammary artery bypass grafts

The internal mammary artery has been advocated for use in bypass grafting owing to its superior long-term patency when compared to saphenous vein grafts. Concern exists that the flow through the internal mammary artery may be inadequate during periods of peak myocardial demand. This flow was investigated in 24 consecutive patients with a mean proximal left anterior descending artery stenosis of 87.5% who were selected for coronary bypass using the internal mammary artery. Within 8 weeks of operation, all were evaluated by exercise thallium 201 scintigraphy. Thallium activity, expressed as a ratio of anteroseptal activity to posterolateral wall activity (or inferior wall activity if the posterolateral wall was deemed abnormal), was 0.97 +/- 0.15. A second group of 25 patients, with normal coronary arteries, was similarly evaluated. The mean septal to posterolateral wall thallium activity ratio for these control patients was 1.0 +/- 0.15. A third group of 26 patients who underwent single-vessel percutaneous transluminal coronary angioplasty of the left anterior descending artery and a fourth group of 28 saphenous vein graft recipients were compared by stress thallium scintigraphy. Thallium 201 activity for the vein graft group (0.96 +/- 0.19) was not significantly different from that for the mammary artery group, whereas the flows obtained with a single attempt at angioplasty were significantly inferior (p less than 0.05). The internal mammary artery provides excellent coronary flow at peak myocardial demand and compares favorably to angioplasty and saphenous vein grafting.     

Symptomatic coronary-subclavian steal corrected by carotid-subclavian bypass

Angina recurred after a left internal mammary-to-left anterior descending coronary artery bypass graft. Subsequent development of a subtotal stenosis in the proximal left subclavian artery caused reversal of flow in the patent internal mammary artery graft, which produced an angiographic steal of myocardial perfusion. Angina and ischemia were relieved by reoperation, which consisted of left common carotid-to-left subclavian artery bypass in conjunction with right internal mammary-to-right coronary artery bypass and aorto-to-lateral circumflex coronary artery bypass with reversed saphenous vein.     

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.     

Combined operation for renovascular hypertension and ischemic heart disease

We have experienced two patients of ischemic heart disease associated with renovascular hypertension. Patient 1 (60-year-old man) underwent LV aneurysmectomy and triple aortocoronary bypass grafting (saphenous vein to diagonal branch, left internal mammary artery to obtuse marginal branch, and right gastroepiploic artery to right coronary artery). Seventy five days after the initial cardiac surgery endarterectomy for the left renal artery and bifurcated Dacron graft implantation for the iliac artery obstruction were performed. Patient 2 (62-year-old woman) underwent simultaneous operation of both right nephrectomy and triple aortocoronary bypass grafting (saphenous vein grafts to obtuse marginal branch and right coronary artery, and left internal mammary artery to left anterior descending artery). Their postoperative courses were uneventful except unstable and high blood pressure for four to seven days after the operation. It appears that it should be decided to achieve either simultaneous or two stage approach for ischemic heart disease associated with renovascular hypertension based on the preoperative cardiac function. And both postoperative cardiac function and hypertension should be carefully managed until the blood pressure becomes stable after the surgery.     

Biochemical composition of human internal mammary artery and saphenous vein

The long-term patency of the internal mammary artery graft is better than that of the saphenous vein graft in coronary bypass surgery because of a low incidence of atherosclerosis in the internal mammary artery. In search of a possible biochemical explanation of the low degree of atherosclerosis in the internal mammary artery we compared the chemical compositions of human internal mammary artery and saphenous vein obtained from 37 patients undergoing coronary bypass surgery. The levels of esterified cholesterol and free cholesterol were higher in the internal mammary artery than in the saphenous vein (p less than 0.001 and p less than 0.01, respectively), but lower than the levels reported in previous studies for coronary arteries. The amount of collagen was higher in the saphenous vein (p less than 0.001). Heparan sulfate was the major glycosaminoglycan fraction in the internal mammary artery, probably reflecting the higher cellularity and thicker media in the arterial rather than in the venous tissue. The level of dermatan sulfate was higher (p less than 0.001) in the saphenous vein than in the internal mammary artery. This difference is in a direction that could favor atherogenesis in the saphenous vein graft.     

A case of ischemic mitral regurgitation treated by mitral annuloplasty (MAP) and coronary artery bypass grafting (CABG)]

A 79-year-old woman with a previous history of myocardial infarction, suffered acute myocardial infarction again. A coronary angiogram revealed triple vessel disease, and a left ventriculogram showed severe mitral regurgitation. The patient fell into cardiogenic shock after cardiac catheterization, and IABP was started. She underwent MAP and saphenous vein bypass grafting to the left anterior descending coronary artery and left circumflex coronary artery. Although the postoperative course was complicated by acute renal failure and respiratory dysfunction, the patient recovered from the operation and was discharged on the 137th postoperative day. Since the operative mortality of conventional valve replacement combined with CABG in ischemic mitral regurgitation has been high, we preferred MAP for this case.     

非体外循环冠状动脉旁路移植术围手术期心肌梗死发生率与移植血管血流量的关系

目的探讨冠状动脉旁路移植术（CABG）中移植血管血流量与围手术期心肌梗死（MI）发生率之间的关系,为临床提供借鉴。方法采集2010年1～6月在北京大学第一医院连续58例因冠心病接受单纯择期非体外循环冠状动脉旁路移植术（（）PcAB）患者的临床资料。术中均采用左乳内动脉（I,IMA）吻合于左前降支（I．AD）,其他靶血管则以大隐静脉（SV）作为旁路移植血管,在关胸前循环状态稳定条件下,应用瞬时流量测定技术测量各移植血管的血流量,并计算移植血管总血流量。根据术后是否发生围手术期MI,将患者分成两组：MI组11例,其中男7例,女4例;年龄67．4±10．3岁;非MI组,47例,其中男38例,女9例;年龄63．3±9．9岁。分析两组患者术前及术中的相关危险因素。结果MI组与非MI组的手术时间差异无统计学意义（205．44±59．6rainVS．183．4±32．4min,t=1．69l,P=0．096）。MI组与非MI组移植血管数量（3．00±1．oo支VS．2．96±0．78支,t=0．154,P=0．878）、LIMA-LAD移植血管血流量（15．40±）1．37mi／minVS．16．50±10．83mJ／min,f=0．301,P=0．764）差异均无统计学意义;MI组与非MI组移植血管总血流量（41．03土19．50ml／minVS．64．09±32．44ml／min,t=2．254,P=0．028）差异有统计学意义。移植血管总血流量〈48．5ml／min为发生MI的危险因素EoR：4．706,95％CI（1．099,20．147）]。结论移植血管总血流量可在一定程度上预测CABG后急性心肌缺血事件的发生,总血流量〈48．5ml／min的患者术后发生围手术期MI的概率将明显增加。     

Modification of repeat lateral minimally invasive direct coronary artery bypass; left axillary artery to circumflex artery bypass

A 69-year-old man underwent triple coronary artery bypass graftings [LITA (left internal thoracic artery)-LAD (left anterior descending artery), SVG (saphenous vein graft)-PD (postac-descending artery), SVG-PL (postero-lateral artery)] 11 years previously. Recently, angina pectoris occurred due to the graft disease of SVG-PL. A repeat modified lateral minimally invasive direct coronary artery bypass (MIDCAB) [left axillary artery-PL using SVG] was performed. The left axillary artery was chosen as inflow vessel for coronary artery bypass graft because of the difficult descending aorta and patent LITA-LAD. Postoperative course was uneventful. The left axillary artery to circumflex artery bypass could be one of the option of the lateral MIDCAB.     

Internal mammary artery grafts: technical factors influencing patency

Eight hundred fourteen patients with internal mammary artery (IMA) coronary artery bypass grafts have been restudied 961 times with coronary arteriography, primarily to evaluate the patency of the grafts in the setting of symptomatic coronary occlusive disease. Their records were reviewed to assess graft patency as related to the technical aspects of coronary artery bypass surgery. Patency was evaluated using life-table analysis of the data. The method of harvesting the IMA played no role in patency. The left anterior descending coronary artery was the recipient coronary artery with the highest patency rate. The left IMA had a significantly higher patency rate than the right IMA. As a group, the IMAs had a significantly higher patency rate than saphenous vein grafts. However, there was no difference between right IMA grafts and saphenous vein grafts. The mammary artery grafts that remained patent throughout the study had a significantly higher blood flow after bypass than did those that became occluded (43.0 +/- 0.9 versus 28.9 +/- 1.8 ml/min; p less than .001).     

Totally endoscopic quadruple coronary artery bypass grafting is feasible using robotic technology

Multivessel robotic totally endoscopic coronary artery bypass grafting is currently under development. Quadruple totally endoscopic coronary artery bypass has so far not been reported. A 75-year-old patient with multivessel coronary artery disease underwent daVinci Si-assisted completely endoscopic placement of a left internal mammary artery bypass to the left anterior descending artery and construction of a right internal mammary artery Y-graft off the left internal mammary artery to the posterior descending artery. The left internal mammary artery was also connected to a diagonal branch as a sequential graft. The obtuse marginal branch was revascularized using an endoscopically harvested vein graft originating from the left axillary artery.     

Utilizing a patent proximal vein graft stump in a case of coronary artery reoperation

A patient was referred for coronary artery bypass reoperation. The right internal mammary artery (RIMA) was anastomosed to the left anterior descending artery (LAD) and a left radial artery graft (RA) was sequentially anastomosed to the posterior descending artery (PDA) and left ventricular branches (LVB) of the right coronary artery (RCA). The patent proximal stump of an occluded saphenous vein graft was used as an interposition segment to lengthen the RA graft, thereby avoiding the need for a further anastomosis on the ascending aorta.     

Clinical results with left axillary to left anterior descending coronary artery bypass

BACKGROUND: The minimally invasive direct coronary artery bypass procedure is not feasible if the left internal mammary artery has been used or has inadequate flow. We have applied a modified minimally invasive direct coronary artery bypass procedure, which uses a graft from the left axillary artery to the left anterior descending coronary artery in such situations. METHODS: The graft is anastomosed to the left axillary artery adjacent to the clavicle and tunneled underneath the vein, where it enters the thorax through the first interspace and courses to the left anterior descending coronary artery along the mediastinum. RESULTS: Since 1997 we have used this operation in 22 patients with a mean age of 70 years (range, 52 to 83 years). All patients were high-risk candidates because of advanced age (70 +/- 7 years), depressed left ventricular function (mean left ventricular ejection fraction, 38% +/- 6%), or previous heart operation (20 of 22, 91%). Conduits for the graft were saphenous vein (n = 18) or radial artery (n = 4). Ten patients were extubated in the operating room, and the mean duration of mechanical ventilation was 5.8 +/- 6 hours. There was one operative death (1 of 22, 4.5%). The mean length of intensive care unit and hospital stay was 1.5 days (range, 1 to 6 days) and 6 days (range, 2 to 15 days), respectively. At a mean follow-up of 6 months, all discharged patients are alive and functionally improved. None have required surgical or catheter-based revascularization of the left anterior descending coronary artery. CONCLUSIONS: The left axillary artery to left anterior descending coronary artery graft should be considered for high-risk patients in whom a minimally invasive direct coronary artery bypass procedure is not possible.     

From Vineberg to bypass: a "second-hand" internal mammary artery.

A patient operated upon 20 years ago for myocardial revascularization with two Vineberg procedures and one coronary artery bypass graft (CABG) on the right coronary artery had a recurrence of unstable angina due to the thrombosis of the left internal mammary artery (IMA) and the right CABG. The right IMA was patent but stenosed distally. Reoperation was performed with a direct end to side anastomosis of the patent right IMA onto the left anterior descending artery and a saphenous vein graft as a CABG on the marginal branch. We comment on the choice of this "second hand" IMA graft and the pathological appearances of the patent IMA.     

Vasoactive drug effects on blood flow in internal mammary artery and saphenous vein grafts

The internal mammary artery is a dynamic coronary graft, whereas the saphenous vein graft is passive. Therefore, potential exists not only for beneficial vasodilation but also for catastrophic spasm of the artery. The purpose of this study was to examine blood flow in the internal mammary and saphenous vein grafts during infusion of drugs that are commonly used after cardiac operations. A canine right heart bypass preparation allowed precise control of cardiac output, blood pressure, and heart rate, which were maintained constant during drug infusion. Both the internal mammary and saphenous vein grafts were constructed so that they perfused the same coronary bed: They were anastomosed in a Y fashion to a ligated anterior descending coronary artery. Electromagnetic flow probes measured graft flow (with the other graft occluded) before and after 15 minutes of drug infusion. The order of drug infusion was randomized and changes were compared by tests for paired differences. Phenylephrine (2 micrograms/kg/min) decreased flow in both the internal mammary and saphenous vein grafts, whereas norepinephrine (0.1 microgram/kg/min) increased flow in both grafts. Epinephrine (0.05 microgram/kg/min) increased mammary artery flow 16% +/- 6% but decreased saphenous vein graft flow 9% +/- 7%. Nitroglycerin (1 microgram/kg/min) significantly increased internal mammary flow (36% +/- 13%), from 47 +/- 7 to 59 +/- 7 ml/min (p less than 0.01), whereas flow decreased significantly in the saphenous vein graft 14% +/- 3%, from 64 +/- 9 to 59 +/- 8 ml/min (p less than 0.01). Nitroprusside (1 microgram/kg/min) decreased mammary artery flow 12% +/- 2%, from 50 +/- 7 to 44 +/- 7 ml/min (p less than 0.01), but increased saphenous vein graft flow 25% +/- 8%, from 64 +/- 9 to 77 +/- 7 ml/min (p less than 0.01). All hemodynamic variables were unchanged, except for norepinephrine, which significantly increased the first derivative of left ventricular pressure. The results suggest that flow through the canine internal mammary artery is changed by the drugs commonly used in perioperative management. Epinephrine and nitroglycerin increased internal mammary artery flow and decreased saphenous vein graft flow, whereas nitroprusside had the opposite effect. The vascular reactivity of the internal mammary artery must be considered when these drugs are used after coronary revascularization.     

Triple coronary bypass in a child with homozygous familial hypercholesterolemia

Here we report triple coronary bypass procedure in a 12-year-old girl with familial homozygous hypercholesterolemia and extensive coronary atherosclerosis. She had successful cardiopulmonary resuscitation at home by her father 4 months before the operation. Total cholesterol level was 1300 mg/dL initially without antilipidemic treatment. Extensive three vessel disease with right coronary proximal stenosis and left coronary ostial stenoses was determined by angiography. Left internal thoracic artery, left radial artery, and saphenous vein grafts were used for coronary revascularization. Saphenous vein graft to right posterior descending artery, radial artery graft to obtuse marginal artery, and LITA to left anterior descending artery anastomoses were performed consecutively. Ten months after the operation, she is in good condition under intensive antilipidemic therapy and weekly lipid apheresis.     

Evaluation of postoperative flow capacity of internal mammary artery

The internal mammary artery has been advocated for use in coronary artery bypass grafting because of its excellent long-term patency. We compared the flow capacities of internal mammary artery and saphenous vein grafts under exercise conditions by means of radionuclide angiocardiography. Fifty-two patients were divided according to the type of bypass graft done to the left anterior descending artery: group 1 comprised 27 patients with the internal mammary artery graft, and group 2 included 25 patients with the saphenous vein graft. Saphenous vein grafts were placed into the right and circumflex systems. Before the operation, global and regional ejection fractions decreased similarly in both groups with exercise. After the operation, the global ejection fraction measured in groups 1 and 2 increased significantly from 54% +/- 2% to 57% +/- 2% and from 54% +/- 1% to 60% +/- 2%, respectively, the anteroseptal ejection fraction from 29% +/- 1% to 32% +/- 2% and from 29% +/- 1% to 35% +/- 1%, respectively, and the apical ejection fraction from 75% +/- 3% to 82% +/- 2% and from 77% +/- 2% to 86% +/- 2%, respectively. There were no differences in exercise-induced increases in the global and regional ejection fractions between groups 1 and 2. Six patients in group 1 had exercise-induced wall motion abnormalities at the anteroseptal and/or apical segments. In contrast, patients in group 2 had no exercise-induced wall motion abnormalities at these segments (p less than 0.05, group 1 versus group 2). Results of this study show that internal mammary artery grafts respond to the increased blood flow demand of exercise in essentially the same way as saphenous vein grafts. However, there seems to be a slightly greater potential for inadequate flow in patients with the internal mammary artery graft, as evidenced by the small group of patients with exercise-induced wall motion abnormalities.