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.
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 explore the independent risk factors for early failure of internal mammary artery grafts after coronary artery bypass grafting (CABG), and to construct and preliminarily evaluate a risk prediction model for the decline of internal mammary artery bridges, optimizing postoperative risk stratification and management strategies for patients. MethodsA retrospective analysis was conducted on patients who underwent CABG at Fuwai Hospital, Chinese Academy of Medical Sciences from January 2016 to January 2020. The primary endpoint was the failure of the internal mammary artery bridge one year after surgery, and the secondary endpoint was major adverse cardiac and cerebrovascular events (MACCE) within five years after surgery, including all-cause death, myocardial infarction, stroke, and revascularization. Patients were divided into a failure group and a non-failure group based on whether there was early failure of the internal mammary artery bridge after surgery. Independent risk factors for the failure of the internal mammary artery bridge were explored through the least absolute shrinkage and selection operator regression and multivariate logistic regression, and a failure risk prediction model was constructed and cross-validated. Patients were stratified for MACCE risk according to the total score of independent risk factors, and the 5-year cumulative MACCE-free rate was drawn using the Kaplan-Meier method. ResultsA total of 657 patients were included, among whom there were 54 patients in the failure group, including 38 males and 16 females, with an average age of (61.85±8.03) years; there were 603 patients in the non-failure group, including 467 males and 136 females, with an average age of (60.45±8.23) years. Multivariate logistic regression analysis showed that non-left main lesion [OR=3.28, 95%CI (1.41, 7.62), P=0.006], pulsatility index (PI)>3.0 [OR=2.63, 95%CI (1.20, 5.75), P=0.016], quantitative flow ratio (QFR)>0.80 [OR=5.57, 95%CI (2.98, 10.41), P<0.001] and in-hospital complications [OR=4.02, 95%CI (1.59, 10.19), P=0.003] were independent risk factors for the failure of internal mammary artery grafts after CABG. Compared with the prediction model in previous literature [area under receiver operating characteristic curve was 0.632, 95%CI (0.561, 0.694)], the risk prediction model constructed with QFR>0.80, PI>3.0, non-left main lesion and in-hospital complications had a higher predictive ability for early failure of internal mammary artery grafts [area under curve: 0.758, 95%CI (0.694, 0.820); net reclassification index: 0.272, 95%CI (0.180, 0.370); comprehensive discriminative improvement index: 0.109, 95%CI (0.059, 0.158); P<0.05]. The risk score of independent risk factors for internal mammary artery graft failure demonstrated significant MACCE risk stratification efficiency in the 5-year patient follow-up, with the high-risk group showing a significantly higher incidence of MACCE compared to the medium and low-risk groups (P=0.001). ConclusionQFR>0.80, PI>3.0, non-left main lesions, and in-hospital complications are independent risk factors for early failure of internal mammary artery grafts after CABG. The constructed risk prediction model based on this has preliminary capabilities in predicting the risk of internal mammary artery graft failure and MACCE risk stratification, which is beneficial for the postoperative management of CABG patients and improving their mid-long term prognosis.
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.
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 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 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.
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.
Objective To evaluate the safety and efficacy of skeletonized and pedicled harvesting of bilateral internal mammary artery (BIMA) in coronary artery bypass graft (CABG) surgery. Methods From December 2015 to May 2017, 152 patients (128 males, 24 females, age of 56.5±6.8 years) underwent CABG using either skeletonized BIMA (s-BIMA group, n=73) or pedicled BIMA(p-BIMA group, n=79). The operative data and post-operative outcomes were analyzed in the s-BIMA group (61 males, 12 females, age of 56.6±7.0 years) and the p-BIMA group (67 males, 12 females, age of 56.3±6.7 years). Results There was no peri-operative mortality. There was no statistical difference in operative time, cardiopulmonary bypass time, aortic cross-clamp time or internal mammary artery graft flow between the two groups. One patient(1.4%) in the s-BIMA group suffered from severe sternal wound complication, which was major sternal wound complication. Five patients (6.3%) in the p-BIMA group suffered from sternal wound complications, including 1(1.3%) with severe complication and 4(5.1%) with minor complication. One(1.4%) patient in the s-BIMA group and 7 (8.9%) patients in the p-BIMA group suffered from chylothorax. The chest tube drainage significantly reduced in the s-BIMA group, both in postoperative day 1(P=0.000) and postoperative day 1-3 (P=0.001). CT angiography showed no stenosis of BIMA in both groups. Conclusion The use of skeletonized BIMA for CABG is safe and efficacious, with less sternal wound complications, chylothorax and chest tube drainage. Skeletonization should be suggested if BIMA is harvested in CABG.