Since the advent of coronary artery bypass grafting (CABG), the selection of bypass conduits has always been one of the most controversial topics in this field. Arterial conduits have received extensive attention due to their excellent biological features and high patency. In recent years, the application of arterial grafting and total arterial grafting in China keeps increasing in recent years, but there is still a gap compared to the Europe and America. Previous clinical studies have indicated the benefits of the total arterial grafting in terms of patency and long-term outcomes, but the advantage of multiple arterial grafting over other procedures is still in need to be confirmed with high-quality randomized controlled trials. This article reviews the clinical application and strategy of total-arterial CABG, aiming to provide objective reference for future clinical research and application.
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.
ObjectiveTo explore the mid-term outcomes achieved by using the left internal mammary artery to saphenous vein composite grafts in off-pump coronary artery bypass surgery (OPCAB) for elderly patients. MethodsA total of 59 elderly patients (≥70 years old) underwent OPCAB by using left internal mammary artery (LIMA) to radial artery (RA) or saphenous vein (SV) composite grafts in Xinhua Hospital between March 2006 and October 2012. There was 37 males and 22 females at age of 72.71±1.95 years. Twenty one patients used LIMA-SV composite grafts (LIMA-SV group), and 38 patients used LIMA-RA composite grafts (LIMA-RA group). ResultsAll patients successfully underwent OPCAB with LIMA-SV or LIMA-RA composite grafts. There was one early death in the LIMA-RA group. No statistical differences in early postoperative outcomes were found between the two groups (P > 0.05). During a follow-up of 12 to 91 months, no patient occurred revascularization. There were no statistical differences in overall survival or graft patency rate, and 1 year, 3 years or 5 years survival rates between the two groups (P > 0.05). The patency rate of LIMA in each group was 100% respectively. There was also no statistical difference in overall patency rate of SV and RA between the two groups at the end of 1 year, 3 years or 5 years (P > 0.05). ConclusionAlthough artery grafts are the best choice for OPCAB, LIMA-SV composite grafts can be used as an alternative graft for elderly patients whose RA or right internal mammary artery is not possible or advisable.
ObjectiveTo investigate the feasibility and effectiveness of using ultrasound to evaluate the internal mammary artery (IMA) and explore the related factors affecting the quality of IMA.MethodsFrom July 2020 to January 2021, for patients who underwent coronary artery bypass grafting at the Department of Cardiovascular Surgery, Fuwai Hospital, ultrasound was applied to measure bilateral IMA at the parasternal second intercostal space. There were 62 males and 18 females with an average age of 59.9±8.3 years. The clinical data of the patients were recorded and analyzed.ResultsA total of 160 IMA were measured. The IMA was detected in 99.4% (159/160), and the one that was not measured was proved to be occluded by enhanced CT. A total of 157 (98.1%) IMA intima were smooth, 2 (1.3%) were found to have uneven intimal thickening and less smooth, and only 1 (0.6%) was occluded. The intravascular diameter, peak systolic flow rate, peak diastolic flow rate, and blood flow rate of the left second intercostal IMA were 1.9±0.3 mm, 66.8±17.7 cm/s, 6.4 (0.0, 9.7) cm/s, 19.7±9.4 mL/min; and those of the right one were 2.1±0.3 mm, 69.7±18.5 cm/s, 6.0 (0.0, 9.2) cm/s and 22.8±11.5 mL/min, respectively. IMA vessel diameter and blood flow were greater on the right than those on the left side in the same individual (P<0.01). In univariate analysis, sex and body surface area were the factors that influenced the size of the IMA vessel among different individuals, and by linear regression analysis, the size of the IMA vessel was only related to body surface area among different individuals. On univariate analysis, diabetes mellitus was the only factor affecting IMA blood flow, with a mean reduction in blood flow of 18.4% (left) and 21.7% (right) in the diabetic group (P<0.05).ConclusionPreoperative evaluation of the IMA using ultrasound over the parasternal second intercostal space is easy, noninvasive, and has a high success rate. The internal diameter of the IMA is positively correlated with body surface area, and blood flow is significantly reduced in patients with diabetes.
Objective To analyze the mean flow in left internal m am mary artery ( L IMA) graft and the influencing factors in off- pump coronary artery bypass grafting ( OPCAB) in the Chinese. Methods One hundred and eighty patients with OPCAB were studied.Transit- tim e flowmeter( TTFM) was utilized to measure and record the L IMA’s blood flow wave,pulsatility index( PI) ,value of mean flow,systolic and diastolic peak flow,vascular resistance,insufficiency ratio and mean blood pressure and to analyze the relationship between mean flow of LIMA and other factors. Results Total mean flow calculated from that of all patients was2 8.19± 2 .89ml/ min( 6 - 178 ml/ m in) .Majority m ean value ( 6 4 .4 % ) was in the range of 10 - 30 ml/ min.Statistics showed that mean flow was significantly related to systolic and diastolic peak flow and vascular resistance rather than the other factors( r=0 .75 , 0 .94 ,- 0 .95 ) . Conclusions For the Chinese,over 10 ml/ min mean flow of L IMA graftis acceptable and ov...更多er 2 2 ml/ min is satisfactory.The diastolic peak flow and vascular resistance are two most important factors in influencing mean flow.
Abstract: Objective To evaluate the outcome of the skeletonized harvesting method of internal mammary artery （IMA） in coronary artery bypass grafting (CABG), and its apply. Methods Two hundred and seventyseven patients (diabetic 33）underwent myocardial revascularization. Left IMA (n=100) or both side of IMA (n=177) were totally skeletonized from the surrounding tissues just by use of the scissors and the titanium clips without the use of electrocautery during harvesting，both side of IMA were harvested in 21 diabetics. Five cases were done with nonextracorporeal circulation CABG and 272 cases were done with extracorporeal circulation CABG. Results The extracorporeal circulation time was 60 to 217min (average 90.1min), aortic clampping time was 30 to 160min(average 53.3min). Operative mortality was 2.2％（6/227）. The IMA grafting has revealed a good quality and blood flow was fluent enough to meet the myocardial need perioperatively. All patients had a disappearance of angina pectoris. Harvesting of both side of IMA in patients, even for those diabetes, had not revealed a higher sternum inflammation. Coronary angiography showed a good patency. Conclusion The skeletonized harvesting method of IMA has a good flow patency rate and a less sternum injury during the harvesting procedure. Harvesting both sides IMA is no longer a contraindication in diabetics.
ObjectiveTo introduce the method and preliminary experience of robot-assisted bilateral internal mammary arteries (BIMA) harvesting for off-pump coronary artery bypass grafting (OPCAB) with 5 grafts via left anterolateral minithoracotomy.MethodsBIMA were harvested using the da Vinci robotic surgical system, and the right internal mammary artery (RIMA) was pulled out of the thoracic cavity through right second intercostal space. Intercepting the distal part of the RIMA for the BIMA composite Lima-Rima Y graft and anastomosing the great saphenous vein with remaining RIMA end to end. The Y graft anastomosed with left anterior descending (LAD) branch and diagonal branches (DIAG), artery-vein graft sequentially anastomosed with blunt round branch, left ventricular posterior branch and posterior descending branch.ResultsThe operation succeeded without hemodynamic instability and intra aortic balloon pump (IABP) implantation or cardiopulmonary bypass. The blood flow of Y graft was 24 mL/min, and the blood flow of artery-vein graft was 30 mL/min. Ventilator assistance time was 35 hours, ICU staying time was 62 hours, and postoperative myocardial enzymes increased temporarily. Postoperative coronary CTA showed that all the grafts were patency, and cardiac ultrasound indicated that the heart function was normal. The patient cured and discharged from hospital 7 days after operation.ConclusionRobot-assisted bilateral internal mammary artery harvesting for OPCAB with 5 grafts via left anterolateral minithoracotomy is feasible, which can achieve complete revascularization.
ObjectiveTo explore the effect of skeletonized left internal mammary artery (LIMA) in coronary artery bypass grafting (CABG). MethodsA total of 122 patients who underwent pure CABG were recruited in the study in the First Affiliated Hospital of China Medical University between January and April 2013. There were 77 males and 45 females with age of 41-76(62.8±10.5) years. They were randomly assigned to received CABG with skeletonized LIMAs (group A, 60 patients) or pedicle LIMAs (the group B, 62 patients) by random digital table. LIMAs were all anastomosised to the left anterior descending artery. ResultsThere was one patient failure in harvesting LIMA process in the group A and B respectively, and they were changed to saphenous vein grafts and excluded from the criteria. There were 2 and 3 patients of postoperative myocardial infarction in the group A and in the group B respectively, with incidence rate of 3.4% and 4.9% respectively (P > 0.05). One patient died in each group during hospitalization with hospital mortality rates of 1.7% and 1.6% respectively (P > 0.05). Complications such as mediastinal infection occurred zero and one patient in the group A and in the group B respectively (P > 0.05). LIMA harvesting time of the group A was statistically longer than that of the group B (30.7±7.2 min vs. 17.2±5.6 min, P < 0.05). In six months of follow-up after surgery, coronary CT showed patency rate of LIMA in the group A and in the group B was 96.8% and 100.0% respectively (P > 0.05). ConclusionThe recent effect of skeletonized LIMA as graft material in CABG is satisfactory.
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.