Objective To study the method to inhibit perioperative internal mammary artery (IMA) spasm from the perspective of muscarinic receptor, and research the function of muscarinic cholinergic receptor subtypes of IMA. Methods IMA segments in vitro with intact endothelium were obtained from 30 patients who underwent coronary artery bypass grafting (CABG). According to muscarinic receptor antagonists of different concentrations， They were divided into control group (not using receptor antagonist), atropine group (nonselective M receptor antagonist), pirenzepine group (M1 receptor antagonist) and Methoctramine group(M2 receptor antagonist) by random number table. The effects of antagonists on vasodilatation were analyzed, Scott ratio was used to calculate affinity index (pD2) and Schild plot was used to count rivalry index (pA2). Results Acetylcholine (Ach)induced concentrationdependentrelaxation response of IMA segments with intact endothelium precontracted with potassium chloride (KCl). The pD2 was 6.92±0.05. The effects of atropine, pirenzepine and methoctramine on doseresponse curve induced by Ach with intact endothelium were all concentrationdependent. With the increase of the concentration of antagonists, the Achinduced doseresponse curves had a significant shift to right(Plt;0.05). Atropine, pirenzepine and Methoctramine competitively antagonized the reaction of vessel to Ach. The pA2 were 9.62±0.15,7.70±0.08 and 630±0.08, respectively. Conclusion The Achinduced relaxation response of IMA with intact endothelium is concentrationdependent. According to the affinity of different antagonist, IMA in Vitro Achinduced relaxation response is implemented by acting on nonneuronal muscarinic cholinergic M1 receptor subtype.
Objective To investigate the impact of different modes of cardiopulmonary bypass （CPB） and cerebral perfusion on cerebral protection in patients with Stanford type A aortic dissection （AD）. Methods Clinical data of 117 patients with Stanford type A AD who underwent surgical therapy from April 2007 to March 2012 in the First Affiliated Hospital of Harbin Medical University were retrospectively analyzed. All the patients were divided into 3 groups according to different modes of CPB and cerebral perfusion they received. In group 1，45 patients received CPB perfusion through the femoral artery and unilateral or bilateral antegrade selective cerebral perfusion （ASCP） after circulatory arrest. In group 2，38 patients received CPB perfusion through the subclavian artery or innominate artery and unilateral or bilateral ASCP after circulatory arrest. In group 3，34 patients received antegrade and retrograde CPB perfusion through both subclavian artery or innominate artery and femoral artery，and unilateral or bilateral ASCP after circulatory arrest. Postoperative occurrence of transient neurological dysfunction （TND），permanent neurological dysfunction （PND） and influential factors were compared between the 3 groups. Results Incidence of postoperative cerebral complications of group 1 was significantly higher than those of group 2 and 3 （37.77% vs. 13.16% vs. 14.71%，P ＜0.05）. During CPB，cooling time of group 3 was significantly shorter than those of group 1 and 2 （35.56±4.35 vs. 40.00±5.63 and 39.58±6.03，P ＜0.05）. There was no statisticaldifference in other influential factors among the 3 groups （P ＞0.05）. Conclusion Antegrade and retrograde CPB perfusionin combination with ASCP has a smooth and quicker cooling rate，may provide better protection for the spinal cord，kidney and intraperitoneal organs and especially decrease the incidence of postoperative cerebral complications，therefore is proved current best method for organ protection.
Objective To compare the graft patency rates of conventional on-pump coronary artery bypass grafting （CCABG） and off-pump coronary artery bypass grafting （OPCAB） at 2 weeks，3 months and 1 year after surgery. Methods Clinical data of 200 patients who underwent coronary artery bypass grafting （CABG） in the First Affiliated Hospital of Harbin Medical University from May 2010 to November 2011 were retrospectively analyzed. All the 200 patients were divided into two groups according to different surgical procedures they received：CCABG group，61 patients including 32 male patients and 29 female patients with their age of 59.8±4.7 years；and OPCAB group，139 patients including 72 male patients and 67 female patients with their age of 59.6±8.9 years. Graft patency of all the patients was evaluated by 256-slice multislice computed tomography angiography （256-MSCTA） at 2 weeks，3 months and 1 year after CABG and compared between two groups. Results At 2 weeks，3 months and 1 year after CABG，the graft patency rates of left internal mammary artery （LIMA） grafting were not statistically different between CCABG group and OPCAB group，as well as those of great saphenous vein （GSV） grafting （P＞0.05）. The 1 year graft patency rates of LIMA grafting of CCABG group and OPCAB group were 92.31% and 91.94% respectively，and 1 year graft patency rates of GSV grafting of CCABG group and OPCAB group were 91.35% and 90.00% respectively. To compare the graft patency rates of different distal anastomotic locations，grafting to the left anterior descending （LAD） coronary artery had significantly higher patency rate than grafting to the right coronary artery （RCA，P＜0.05）. The 1 year graft patency rates of LAD grafting and RCA grafting were 97.78% and 85.90% respectively. But there was no statistical difference in graft patency rates at different respective distal anastomotic locations between OPCAB group and CCABG group （P＞0.05）. To compare early clinical outcomes of two groups，postoperative mechanical ventilation time，length of ICU stay，24-hour mediastinal drainage，24-hour blood transfusion，length of hospital stay，and hospitalization cost of OPCAB group were significantly shorter or lower than those of CCABG group （P＜0.05）. Conclusion Short-term graft patency rates of CCABG and OPCAB are quite similar. Patency rate of grafting to LAD is higher than that of grafting to RCA. OPCAB can produce better perioperative clinical outcomes than CCABG.