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.
Objective To investigate the use of intraoperative transit time flow measurement （TTFM） to accuratelyevaluate graft patency during sequential coronary artery bypass grafting （CABG）. Methods Clinical data of 131 patientsundergoing sequential off-pump coronary artery bypass grafting （OPCAB） with the great saphenous vein （with or without internal mammary artery） as graft vessels in Beijing Anzhen Hospital from April 2012 to January 2013 were retrospectivelyanalyzed. There were 92 male and 39 female patients with their age of 61.35±8.24 years. During the operation，2 methods were used to measure mean blood flow volume，pulsatility index （PI） and diastolic filling （DF） of the graft vessels. For thenon-blocking method，blood flow in graft vessels was maintained，and TTFM was applied 2 cm proximal to the anastomoticsite in graft vessels to record above parameters. For the blocking method，blood flow in graft vessels was temporally blockedby clipping distal graft vessels with an atraumatic bulldog clamp，and TTFM was applied 2 cm proximal to the anastomotic site in graft vessels to record above parameters. Results Blood flow volumes of the diagonal branch （27.43±15.22 ml/minvs. 59.28±30.13 ml/min），obtuse marginal branch （26.14±19.74 ml/min vs. 47.19±24.27 ml/min） and posterior left ventr-icular branch （19.16±8.92 ml/min vs. 38.83±20.11 ml/min） measured by the blocking method were significantly smallerthan those measured by the non-blocking method （P＜0.05） . PI values of the diagonal branch （2.93±1.30 vs. 2.31±0.91），obtuse marginal branch （2.62±1.17 vs. 2.01±0.87） and posterior left ventricular branch （2.33±0.92 vs. 1.80±0.73） meas-ured by the blocking method were significantly higher than those measured by the non-blocking method （P＜0.05）. There was no statistical difference in DF values measured by 2 methods at respective anastomotic sites，and all DF values were higher than 50%. Non-blocking method identified 1 anastomotic site and blocking method identified 3 anastomotic sites that were not patent，and these anastomotic sites became patent after graft reconstruction. Conclusion Blood flow velocity of sequential grafts is higher than that of single grafts，indicating that sequential grafts have the advantages of high blood flow volume and low risk of thrombosis. Blocking method can more accurately evaluate graft patency at the anastomotic sites and sensitively identify graft vessels that are not patent，which is helpful for anastomotic site reconstruction in time and enhancement of successful rate of CABG.
Objective To investigate the protective effects of antitumor necrosis factor-α antibody （TNF-αAb） on lung injury after cardiopulmonary bypass （CPB） and their mechanisms. Methods Forty healthy New Zealand white rabbits，weighting 2.0-2.5 kg，male or female，were randomly divided into 4 groups with 10 rabbits in each group. In groupⅠ，the rabbits received CPB and pulmonary arterial perfusion. In group Ⅱ，the rabbits received CPB and pulmonary arterial perfusion with TNF-αAb. In group Ⅲ，the rabbits received CPB only. In group Ⅳ，the rabbits only received sham surgery. Neutrophils count，TNF-α and malondialdehyde （MDA） concentrations of the blood samples from the left and right atrium as well as oxygenation index were examined before and after CPB in the 4 groups. Pathological and ultrastructural changes of the lung tissues were observed under light and electron microscopes. Lung water content，TNF-α mRNA and apoptoticindex of the lung tissues were measured at different time points. Results Compared with group Ⅳ，after CPB，the rabbitsin group Ⅰ to group Ⅲ showed significantly higher blood levels of neutrophils count，TNF-α and MDA（P＜0.05），higherTNF-α mRNA expression，apoptosis index and water content of the lung tissues （P＜0.05），and significantly lower oxyg-enation index （P＜0.05） as well as considerable pathomorphological changes in the lung tissues. Compared with group Ⅱ，after CPB，the rabbits in groups Ⅰ and Ⅲ had significantly higher blood concentrations of TNF-α （5 minutes after aortic declamping，220.43±16.44 pg/ml vs.185.27±11.78 pg/ml，P＜0.05；249.99±14.09 pg/ml vs.185.27±11.78 pg/ml，P＜0.05），significantly higher apoptosis index （at the time of CPB termination，60.7‰±13.09‰ vs. 37.9‰±7.78‰，P＜0.05；59.6‰±7.74‰ vs. 37.9‰±7.78‰，P＜0.05），significantly higher blood levels of neutrophils count and MDA （P＜0.05），significantly higher TNF-α mRNA expression and water content of the lung tissues （P＜0.05），and significantly loweroxygenation index （P＜0.05） as well as considerable pathomorphological changes in the lung tissues. Compared with groupⅠ，rabbits in group Ⅲ had significantly higher above parameters （P＜0.05） but lower oxygenation index （P＜0.05） only at 30 minutes after the start of CPB. Conclusion Pulmonary artery perfusion with TNF-αAb can significantly attenuate inflammatory lung injury and apoptosis of the lung tissues during CPB.
Objective To evaluate the efficacy and clinical significance of bipolar radiofrequency ablation in the treatment of left ventricular aneurysm with ventricular arrhythmias guided by CARTO mapping system. Methods From September 2009 to December 2015, 56 patients with ventricular aneurysm following myocardial infarction were enrolled. All patients suffered different levels of angina pectoris symptoms evaluated by Holter (the frequencies of ventricular arrhythmias more than 3 000 per day). They were divided into two groups according to random ballot and preoperative communication with patients' family members: a bipolar radiofrequency ablation group (n=28, 20 males, 8 females, mean age of 61.21±1.28 years) receiving off-pump coronary artery bypass grafting (OPCABG), ventricular aneurysm surgery combined with bipolar radiofrequency ablation, and a non-bipolar radiofrequency ablation group (n=28, 22 males, 6 females, mean age of 57.46±1.30 years) receiving OPCABG and single ventricular aneurysm surgery. The grade of cardiac function and ventricular arrhythmia was compared between the two groups during pre-operation, discharge and follow-up. Results All patients were discharged successfully. There was no in-hospital death in both two groups. One patient in the non-radiofrequency group had cerebral infarction. All patients were re-checked with Holter before discharge and the frequency of ventricular arrhythmias significantly decreased compared to that of pre-operation in both groups, and was more significant in bipolar radiofrequency ablation group (1 197.00±248.20 times/24 h vs. 1 961.00±232.90 times/24 h, P<0.05). There was significant difference in duration of mechanical ventilation and ICU stay between the two groups (P<0.05). The left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) significantly improved (P<0.05) after operation in both groups. Conclusion The clinical efficacy of bipolar radiofrequency ablation in the treatment of ventricular aneurysm with ventricular arrhythmia guided by CARTO mapping is safe and effective, but its long-term outcomes still need further follow-up.