Objective To evaluate the outcome and explore the mechanism of coronary vein bypass grafting （CVBG） performed by anastomosing the right internal mammary artery with the middle cardiac vein via off-pump surgery. Methods Twelve Chinese experimental miniswines （either male or female, age from 7 to 10 months, body weight 40±5 kg） with severely diffuse stenosis in the right coronary artery were randomly divided into control group and experiment group with 6 miniswines in each group, using a random number table method. CVBG was performed in the experiment group and sham surgery was performed in the control group. To assess cardiac function, graft flow, graft patency and micro-circulation reperfusion of ischemia myocardium, following measurements were conducted. Eight weeks after right coronary endarterectomy, transthoracic echocardiography was performed for both groups. Coronary angiography, graft flow and echocardiography were performed or measured 6 hours and 3 months after CVBG or sham surgery. Measurement of myocardial blood flow with non-radioactive colored microspheres was also conducted 3 months after surgery for two groups. Results There was no statistical difference in cardiac function 8 weeks after right coronary endarterectomy between the two groups. There were significant improvements in cardiac systolic and diastolic function （ejection fraction 3 months after operation: 52%±6% vs. 44%±5%, t=-2.500, P=0.031） in the experiment group after CVBG compared with the control group. Graft flow of the experiment group 6 hours and 3 months after CVBG were 44.50±5.86 ml/min and 43.33±5.01ml/min respectively （P=0.718）, and pulsatility index （PI） was 0.73±0.14 and 0.80±0.14 respectively（P=0.858）. Internal mammary artery grafts and the anastomoses were all patent without stenosis, documented by coronary artery angiography for the experiment group 6 hours and 3 months after CVBG. Myocardial flow in all aspects especially in the subendocardial layer, estimated by non-radioactive colored microsphere injection, was significantly higher in the experiment group after CVBG than that of the control group, transmural flow was 0.33±0.05ml/（g • min） vs. 0.19±0.03 ml/（g • min） （P＜0.05）. Conclusion Ischemic conditions of the myocardium can be relieved by CVBG using internal mammary artery in a short-term to medium-term period. The mechanism may be due to improvement of the myocardial micro-circulation.
ObjectiveTo investigate surgical treatment strategies for diffuse coronary artery disease (CAD). MethodsFrom January 2003 to June 2013, 92 patients with diffuse CAD received complete coronary revascularization including coronary artery bypass grafting (CABG)and coronary endarterectomy (CE)in the First Affiliated Hospital of China Medical University. There were 63 male and 29 female patients with their age of 52-81 (68.7±10.5)years. After CE and during follow-up, coronary CT angiography (CTA)was used to assess graft patency, and improvement of patients' cardiac function and angina symptoms were observed. ResultsTarget vessel diameter of the 92 patients was all larger than 1.5 mm after CE. Sixty-three patients (with 69 CE grafts)received intraoperative graft blood flow measurement, showing 59 grafts (85.5%)with satisfactory blood flow[blood flow 13-42 (23.4±12.7)ml/min, pulsatility index (PI)1.6-4.2 (2.1±1.1)]. Six patients (6.5%)had perioperative myocardial infarction (MI), and 4 patients (4.3%)died within 30 days after surgery including 2 patients with acute MI and cardiogenic shock, 1 patient with low cardiac output syndrome and multiple organ failure, and 1 patient with massive cerebral infarction. Seventy-three patients (83%)were followed up for 6-108 (49.3±26.7)months after discharge, and 15 patients were lost during follow-up. During follow-up, coronary CTA showed graft patency of 83.9% after CE. Four patients (5.5%)died including 1 patient with heart failure and pulmonary infection, 1 patient of unexplained sudden death, 1 patient with cerebral hemorrhage, and 1 patient with lung cancer. Five-year survival rate was 87% after CE. Six months after CE, ejection fraction (EF)was significantly higher than preo-perative EF (55.6%±9.7% vs. 50.2%±10.5%, P < 0.05), patients' cardiac function significantly improved, and their angina symptoms were significantly relieved. ConclusionCABG with CE can improve coronary revascularization for patients with diffuse CAD, and short-and long-term results are satisfactory.