| BackgroundsThe internal mammary artery(IMA) has become the first choice in myocardiac revascularization due to its higher long-term patency rate.The expanded use of this ideal conduit for seqential grafting has enhanced its application.The objective of this study was to assess the flow of orthotopic and sequential left internal mammary artery(LIMA) grafting in off-pump coronary artery bypass grafting(OPCABG),and present the objective evidence for the clinical using.MethodsBetween Mar.2008 and Mar.2009,56 consecutive patients underwent OPCABG with sequential LIMA bypass grafts were included in the study,there were 30 men and 26 women,a mean age of 62(55～75) years old,mean weight was 65(52～80) Kilograms.There were 234 grafts in all,and the average was 4.18.All patients were diagnosed as coronary artery desease(CAD) with 3 branches stenosis by coronary angiography(CAG) before cardiac surgery,3 (5.36%) patients had the main left coronary artery stenosis among them.Angina was presented in the total 56 patients and 17(30.3%) were in Canada Heart Association ClassⅢ,22(40.3%) in classⅣ.The anesthesia method of inhalation combined with vein injection were used. Maintaining the mean blood pressure(BP) 60～75mmHg and heart rate(HR) 48-58 bpm.Nitroglycerin(0.2ug/kg.min) was administrated during the procedure.The LIMA combined with the radial artery(RA) or saphenous vein were used as bypass grafts.LIMA's blood flow was meassured,when the hemodynamics stabilized using Medi-stim Butterfly Flowmeter(2002,Oslo,Norway ) Measurement of the main LIMAs' blood flow after a small area was educed,and then after all the lateral branch were mutilated.When the sequential anastomosis was finished,the main LIMAs' blood flow were meassured.Statistic analysis was used with SPSS13.0 statistic software to analyze all the patients' data.Results①There were no statistically differences among all the patients.②The sequential anastomosis with LIMA was performed in all the 56 patients:52 patients with 2 sequential anastomosis and 4 patients with 3 sequential anastomosis.LIMA to 2 diagnal branches and LAD was performed in 3 patients,and LIMA to the diagnal,middle and proximal LAD was performed in the other one.③The LIMAs' flow and PI were significantly different between LIMA's orthotope (32±5.0ml/min 1.9±0.2) and LIMA's free state(10±1.2ml/min 3.0±0.4) respectively(P＜0.05).But LIMAs' mean flow and PI shown no differences between LIMA's sequential anastomosis(30±3.1ml/min 2.1±0.2) and LIMA's orthotope(32±5.0ml/min 1.9±0.2)(P＞0.05).TTFM show diastolic-dominated waves in LIMAs of all.④The levels of CK-MB were normal and no patients experienced hospital complication,such as ventrical arrhythmia,peri-operative myocardial infarction and low cardiac output syndrome. Conclusions①The LIMA flow is related with peripheral resistance vessel,and there is a trend that the flow of LIMA are related to the number of sequential grafts of LIMA.②The LIMA possesses adequate volume rsvd,and can provide adequate volume flow to myocardium surplied by diagonal,intermediat remus,left interventricular branch and even more areas.③The LIMA sequential anastomosis can ensure the coronary bypass graft arterialization for a long-term pateney rate. |
