Changes Of Endothelial Factor After Selective Retrograge Coronary Venous Bypass Under Different Pressure

ObjectiveCoronary artery bypass graft (CABG) ,as a effective therapy for coronary artery disease(CAD),has been extensively accepted recently.The condition of target vessel is poor in severe CAD , especially in the patient with diabetes. As for the small diameter of distal coronary artery,the unsmooth endangium and the high resistance of outflow tract ,the reocclution and perioperative myocardial infarction may frequently occur.Historically, CABG with percutaneous transmyocardium laser revascularization (PTMR) and single PTMR was the mainstay of therapy for those patient ,but the result of opration was not satisfied.The critical patient only wait for cardiac transplantation,and most of them dead in the waiting time . The selective retrograde coronary venous bypass(SRCVB) could have the distinct advantage for the patient with diffused lesion and distal occlusion of coronary artery. This research investigate the effect of SRCVB and different pressure on endothelial factor of myocardial ischemia modle in dogs ,and demonstrate that SRCVB is the most effective therapy for the patient with diffused lesion of coronary artery.Methods 1 .Divided experimenttal groups24 dogs were randomly divided into 3 groups:(1)ischemia group;(2)SRCVB with 60nmmHg perfusion pressure ; (2)SRCVB with 90nmmHg perfusion pressure.2.Establish modle of myocardial ischemiaThe left anterolateral thoracotomy is performed after using 3% pentobarbital sodium(50mg/kg). After heparinization ,a Prolene purse string is sutured at the ascending aorta .A catheter with pressure transducer used in cardiopulmonary bypass is placed through the purse string,and continuously monitor perioperative hemodynamics.The near part of the posterior descending artery (PDA)was ligated in the ischemia group.3. Establish modle of SRCVBIn the SRCVB group ,we use the great saphenous vein for the bypass graft. The venotomies were performed with a No. 11 scalpel blade and fine vascular clip .The proximal anastomosis is performed on the descending aorta in an end-to-side manner using arunning 6-0 Prolene suture technique .A similar anastomosis is performed to middle cardiac vein(MCV) with 7-0 Prolene suture.After estalished the flow through the graft ,Ligated the PDA and MCV in the same time .Utilize dopamine and nitroglycerin to control the blood pressure of dogs ,and guarantee the perfusion pressure less then 60mmHg or 90mmHg in respective group .4.Collection and examination of the specimens(1) Blood samples collected from aortic catheter before ligation and in 60min,120min,240min after ligation were storaged and measured.(2) We cut parts of local cardiac muscle supply by PDA in all group.The myocardium was put into 3% paraformaldehyde immediately ready for immunohistochemistry.(3) In SRCVB group ,10 ml ink were utilized to perfuse the heart through SVG graft in vivo . After paraffin imbedded, observe through the microscope. 5.Analysis of statistics:MS-SPSS software 14.0 was used for statistical analysis .Measure data is presented as "mean±standard error ",received one-way ANOVA between the three group. Results were significant when P<0.05 and even significant when P<0.01Results1,The differences of NO and ET were not statistically significant before ligation of PDA in all group (p>0.05) ,but changed significantly in SRCVB group after the ligation (p<0.01) .2,The expression of iNOS : There was low expression in normal myocardium;but there significant differences shown at all group.3,In 60mmHg group, the ink perfused retrogradely from graft distributed the myocardium tissue uniformly. Compared with 60mmHg group,there was obvious swelling of myocardium in 90mmHg group.Conclusions1,SRCVB could guarantee effective perfusion of myocardium and ameliorate the abnormal concentration of endothelial factor in ischemic myocardium, decrease injury to endothelial cell and protect the heart.2,The low pressure flow through selective ligated coronary venous could guarantee effective perfusion of myocardium.the high pressure of perfusion could make myocardium swelling.3,After the ligation of proximal end of MCV ,the related myocardium could be perfused effectively by distal arterialization in situ .SRCVB, fitting to patients with diffused lesion and distal occlusion of coronary artery, was performed safely with effectively clinical outcomes.