Release of S100B during coronary artery bypass grafting is reduced by off-pump surgery

Background. S100B, a plasma marker of brain injury, was compared after coronary artery bypass grafting with and without cardiopulmonary bypass (CPB).

Methods. Fourteen patients with off-pump operations and 18 patients with CPB were compared. Seven patients in the off-pump group underwent a minithoracotomy and received only an arterial graft, whereas 7 patients underwent sternotomy and received both an arterial and one or two vein grafts. S100B was measured in arterial plasma using an immunoassay with enhanced sensitivity.

Results. S100B before the operation was 0.03 μg/L. At wound closure, S100B in patients of the off-pump and CPB groups reached a maximum level of 0.22 ± 0.07 and 2.4 ± 1.5 μg/L, respectively (p < 0.001). No strokes occurred. Patients without CPB receiving arterial and vein grafts released slightly more S100B (p < 0.05) than patients with only arterial grafting. In patients undergoing CPB, S100B increased slightly before aortic cannulation (p < 0.001), to the same level as the maximum reached for the non-CPB group.

Conclusions. Coronary artery bypass grafting with CPB caused a 10-fold greater increase in S100B than off-pump grafting. S100B release after off-pump sternotomy with vein grafting was slightly greater than in arterial grafting through a minithoracotomy.     

Predictors of atrial fibrillation after off-pump coronary artery bypass graft surgery

OBJECTIVE: Atrial fibrillation is the most common complication after coronary artery bypass graft surgery. This arrhythmia may lead to hemodynamic compromise, prolonged hospitalization, and increased risk for cerebral thromboembolism. Older age is the only variable consistently associated with the development of postoperative atrial fibrillation; however, no strong predictive model exists. The purpose of this study was to identify perioperative characteristics associated with new-onset atrial fibrillation in patients undergoing off-pump coronary artery bypass grafting. DESIGN: Prospective, observational. SETTING: University tertiary care hospital. PARTICIPANTS: One hundred sixty consecutive patients undergoing off-pump coronary artery bypass grafting. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Incidence of postoperative atrial fibrillation was the major outcome. Atrial fibrillation occurred in 33 patients (20.6%). Multivariate analysis identified reintervention (odds ratio 26.8), revascularization of the ramus medianus (odds ratio 3.9), and age (odds ratio 1.069 per year) as the only independent predictors of postoperative atrial fibrillation. All patients were in sinus rhythm at hospital discharge. One hospital death was noted. CONCLUSIONS: Despite the less invasive approach, the incidence of postoperative atrial fibrillation is high after off-pump coronary artery bypass grafting. Older age, grafting of the ramus medianus, and a redo operation were predictors of new-onset postoperative atrial fibrillation. It is possible that left atrial stretching with heart dislocation during revascularization of the lateral wall could lead to postoperative atrial fibrillation.     

Impact of off-pump coronary artery bypass surgery on postoperative renal dysfunction: current best available evidence

SUMMARY:   Renal dysfunction is a serious complication after coronary artery bypass surgery with cardiopulmonary bypass. Cardiopulmonary bypass-related non-pulsatile flow, hypothermia, haemolysis, systemic inflammatory reactions and emboli are mentioned as possible causes for this postoperative renal dysfunction. In an attempt to avoid these deleterious effects of cardiopulmonary bypass, off-pump coronary artery bypass surgery has been rediscovered. Resurgence of interest in off-pump coronary artery bypass surgery is associated with the expectation that avoiding deleterious effects of the cardiopulmonary bypass leads to better outcomes and possibly decreased costs and resource use. We are currently practising in an era of evidence-based medicine that mandates the prospective randomized controlled trial as the most accurate tool for determining a treatment benefit compared with a control population. The present review article attempts to evaluate the current best available evidence from randomized controlled trials on the impact of off-pump coronary artery bypass surgery on postoperative renal dysfunction.     

Characteristic changes in cerebral perfusion during on-pump and off-pump coronary artery surgery

Objective: We investigated the cerebral perfusion status during on-pump or off-pump coronary artery bypass grafting (CABG). Methods: We monitored somatosensory evoked potential (SEP) and regional cerebral oxygen saturation (rSO₂) as parameters of cerebral perfusion in an on-pump group (n=10) and an off-pump group (n=16). The percent changes from control values were calculated before, during, and after aortic clamping, and after weaning from cardiopulmonary bypass, in the on-pump group. In the off-pump group, these were calculated before, during, and after heart displacement for distal anastomosis. Results: In the on-pump group, the amplitudes of the SEP were significantly enhanced during and after aortic cross-clamping and were associated with a significant decrease in rSO₂. Latency was prolonged immediately after aortic cross-clamping, but was shortened afterwards. There was little change in these parameters throughout the operation, in the off-pump group. Conclusions: Cerebral perfusion remains stable during off-pump CABG. The etiology of a simultaneous increase in SEP amplitude and decrease in rSO₂ during the rewarming period in the on-pump group requires further investigation.     

Early results of off-pump coronary artery bypass

Objective: The purpose of this study is to compare the operative results of off-pump coronary artery bypass (OPCAB) and on-pump (conventional) coronary artery bypass (CCAB), to clarify qualitative problems and whether OPCAB is less invasive or not. Methods: OPCAB was consecutively performed in 63 patients and CCAB in 63 patients between July 1998 and December 2003. Results: The mean number of bypass grafts was 2.43 ±0.82 in the OPCAB group and 2.70±0.71 in the CCAB group (p=0.096). In-hospital mortality was 0% in the OPCAB group and 3.2% in the CCAB group. The incidence of perioperative myocardial infarction was 0% in the OPCAB group and 3.2% in the CCAB group. The incidence of postoperative major complications was significantly lower in the OPCAB group than in the CCAB group (OPCAB group=4 complications, CCAB group=13 complications). Cerebrovascular accidents occurred in 1.6% of patients in both groups. The incidence of sternal infection or mediastinitis was 0% in the OPCAB group and 3.2% in the CCAB group. The early patency rate of graft was 94.0% in the OPCAB group and 92.8% in the CCAB group, and was not significantly different (p=0.822). Conclusion: Operative mortality and major complications after surgery in OPCAB were lower than that in CCAB. The early patency rate in OPCAB was as good as that in CCAB. It is considered that OPCAB is less invasive and the quality of bypass in OPCAB is as good as that in CCAB.     

舒芬太尼在非体外循环冠脉搭桥术应用中的临床研究

目的 观察舒芬太尼在非体外循环冠状动脉搭桥手术应用中的安全性和有效性.方法 择期行OPCABG病人54例,被随机分成两组,舒芬太尼组和芬太尼组,每组27例,麻醉诱导应用丙泊酚1 mg/ks～2 ms/ks,同时分别静注舒芬太尼0.5 μg/ks～1μg/kg,或芬太尼4 μg/ks-8 μg/ks,同时吸入安氟醚维持麻醉,持续输注舒芬太尼0.08 μg·ks-1min-1,或芬太尼0.6 μg·ks-1·min-1.记录各组气管插管、切片、麻醉维持和拨除气管导管各时间的收缩压和舒张压.结果 在气管插管过程中,浅麻醉反应的病人数舒芬太尼组明显低于芬太尼组,在气管插管切皮,麻醉维持和拔管期间,芬太尼组收缩压、舒张压明显高于舒芬太尼组,术后清醒和拔管时间两组病人无统计学差异.结论 舒芬太尼的麻醉效果优于芬太尼,舒芬太尼能提供术中更稳定的血液动力学.     

Surgical considerations in off-pump coronary artery bypass grafting

Off pump coronary artery bypass grafting remains an important technique particularly in the care of high-risk patients. Consistently successful adoption of this technique requires a cooperative team approach and standardization across all phases of patient care. This review describes our approach to off pump coronary surgery.     

Haemodynamic effects of a milrinone infusion without a bolus in patients undergoing off-pump coronary artery bypass graft surgery

The haemodynamic effects of a continuous infusion of milrinone without an initial bolus dose were evaluated in patients undergoing off-pump coronary artery bypass graft surgery. After internal mammary artery harvest, milrinone 0.5 microg.min(-1).kg(-1) (29 patients) or a normal saline infusion (33 patients) was started and continued until all graft anastomoses were completed. Haemodynamic variables were recorded before application of the tissue stabiliser, at 1, 3, 5 and 10 min after the application of the stabiliser, and after its removal. The administration of a milrinone infusion was associated with a smaller decrease in cardiac output and mixed venous oxygen saturation during all the coronary artery anastomoses, with no severe complications and a decreased dose of norepinephrine infused to maintain systemic arterial pressure.     

Comparison of three different epidural solutions in off-pump cardiac surgery: pilot study

Background. Immediate extubation using thoracic epidural analgesia(TEA) has become more popular after off-pump coronary arterybypass grafting (OPCAB). In this randomized prospective double-blindstudy, we present the first comparison of preoperative and postoperativehaemodynamics during different regimens of TEA for immediateextubation after cardiac surgery. Methods. Sixty patients undergoing OPCAB were enrolled in thisstudy. TEA was installed >1 h before application of heparinat levels T2–T4. Analgesia was provided by bupivacaine0.25%, 8 ml, 15 min before surgery and extubation, and at 10ml h^–1 during surgery and up to 72 h afterwards usingone of the following regimens: bupivacaine 0.125% alone, bupivacaine0.125% with fentanyl 3 µg ml^–1 or bupivacaine 0.125%with clonidine 0.6 µg ml^–1. Patients were block-randomizedfor one of the three treatments. Pain scores and infusion ratesof TEA were assessed up to 48 h after surgery. Respiratory functionwas assessed by Pa_O2 and Pa_O2 immediately after surgery, andhaemodynamic stability was recorded in the form of heart rateand diastolic and systolic blood pressure. Results. Patient characteristics, respiratory function and haemodynamicstability did not vary between the three groups. Pain controlwas very good and was not significantly different between thegroups using similar infusion rates after surgery. Paraesthesiain dermatomes T1 or C8 occurred equally in all three groups.There was no neurological complication related to TEA in thisstudy. Conclusions. We conclude that immediate extubation after OPCABusing TEA is feasible with different TEA regimens. Respiratoryfunction, haemodynamic stability and pain control are not differentbetween TEA with bupivacaine alone, bupivacaine with fentanylor bupivacaine with clonidine.     

OPCAB surgery is cost-effective for elderly patients

Abstract

Objective. To determine the cost-effective operative strategy for coronary artery bypass surgery in patients above 70 years. Design. Randomized, controlled trial of 900 patients above 70 years of age subjected to coronary artery bypass surgery. Patients were randomized to either on-pump or off-pump coronary artery bypass surgery. Data on direct and indirect costs were prospectively collected. Preoperatively and six months postoperatively, quality of life was assessed using EuroQol-5D questionnaires. Perioperative in-hospital costs and costs of re-intervention were included. Results. The Summary Score of EuroQol-5D increased in both groups between preoperatively and postoperatively. In the on-pump group, it increased from 0.75 (0.16) (mean (SD)) to 0.84 (0.17), while the increase in the off-pump group was from 0.75 (0.15) to 0.84 (0.18). The difference between the groups was 0.0016 QALY and not significantly different. The mean costs were 148.940 D.Kr (CI, 130.623 D.Kr–167.252 D.Kr) for an on-pump patient and 138.693 D.Kr (CI, 123.167 D.Kr–154.220 D.Kr) for an off-pump patient. The ICER base-case point estimate was 6,829,999 D.Kr/QALY. The cost-effectiveness acceptability curve showed 89% probability of off-pump being cost-effective at a threshold value of 269,400 D.Kr/QALY. Conclusions. Off-pump surgery tends to be more cost-effective than on-pump surgery. Long-term comparisons are warranted.     

非体外循环与改良灌注体外循环下冠状动脉旁路移植术对心肌损伤影响558例的回顾性队列研究

目的 探讨体外循环下冠状动脉旁路移植术(ONCAB)与非体外循环冠状动脉旁路移植术(OPCAB)对心肌损伤的差异.方法 2017～2019年北京安贞医院对558例冠状动脉粥样硬化性心脏病患者施行了冠状动脉旁路移植术,根据是否应用改良灌注的体外循环,将患者分为两组.OPCAB组(OP组):465例,男282例、女183例...     

Perioperative myocardial infarction in patients undergoing off-pump coronary artery bypass grafting

Two patients in whom myocardial infarction in the inferior wall occurred after off-pump coronary artery bypass grafing (OPCAB) are described. In both patients, the right coronary artery had no critical lesion and was not grafted. There was no ischemic episode during operation. Coronary artery spasms and/or intracoronary thrombus formation may have been causes of these events. To our knowledge, this is the first report on perioperative myocardial infarction in OPCAB.     

Brain injury after adult cardiac surgery

Despite remarkable progress in surgical, cardiopulmonary bypass and anaesthetic techniques during the last three decades, brain damage remains an important complication of adult cardiac surgery. Effective brain protection strategies are already implemented today, but ongoing research is needed to meet the challenges faced in operating on increasingly old and disabled patients. The incidence of brain injury may be reduced by modifying the surgical procedure according to carotid duplex scanning and epiaortic echocardiography, by using techniques to reduce microembolization during cardiopulmonary bypass and by optimizing patient temperature during and after surgery. Increased knowledge will aid in choosing the best procedure or combination of procedures in each case to ensure that risks do not outweigh benefits.     

Changes in jugular bulb oxygen saturation during off-pump coronary artery bypass graft surgery

BACKGROUND: The effect of haemodynamic derangement during coronary artery anastomosis in off-pump coronary artery bypass surgery on cerebral blood flow has not been elucidated. Jugular bulb oxygen saturation is a useful indicator of cerebral blood flow provided that the cerebral metabolic rate is constant. This study was designed to evaluate the changes in jugular bulb oxygen saturation during off-pump coronary artery bypass surgery. METHODS: With IRB approval, 48 patients were included. After anaesthesia, an 18-G catheter was introduced into the jugular bulb. Haemodynamic variables and oxygen profiles from gas analysis of jugular bulb blood and arterial blood were obtained: after sternotomy (baseline); at 5 min after the beginning of the anastomosis of the left anterior descending artery, obtuse marginal artery, and right coronary artery; and after sternal closure. RESULTS: Cardiac index and mixed venous oxygen saturation decreased significantly during anastomosis of all three arteries compared to the baseline value. Although the changes in jugular bulb oxygen saturation during anastomosis were statistically significant compared to its baseline value, jugular bulb oxygen saturation remained within normal limit throughout the study. CONCLUSIONS: Jugular bulb oxygen saturation, which represents the global cerebral oxygenation, was well maintained during the anastomosis of all coronary arteries despite significant haemodynamic changes during off-pump coronary artery bypass (OPCAB).     

非体外循环冠状动脉旁路移植术患者术中血糖波动水平与短期预后的关系

Objective To investigate the effect of intraoperative fluctuation in blood glucose concentration (BGCF) on short-term clinical outcomes in patients after off-pump coronary artery bypass graft (CABG) .Methods Two hundred and fourteen ASA Ⅰ -Ⅲ patients ( NYHA grade Ⅰ -Ⅲ ) of both sexes aged 18-64 yr with body mass index 23-29 kg/m2 underwent elective off-pump CABG. Their left ventricular ejection fraction was ≥30% .Blood samples were obtained once an hour for determination of blood glucose concentration (BGC) between 10 min after induction of anesthesia and 10 min after closure of sternum. The maximum and minimum BGCs were record-ed . Intraoperative BGCF was defined as the difference between the maximum and minimum BGCs. Other factors which may influence clinical outcome were also recorded, including prolonged ICU stay ( ≥24 h), prolonged me-chanical ventilation ( ≥12 h) , postoperative complications (cardiac insufficiency secondary to operation, arrhyth-mia, myocardial infarction, respiratory insufficiency, stroke, infection, pleural effusion and surgical bleeding) and prolonged postoperative hospital stay ( ≥ 7 d) . The patients were divided into 2 groups using intraoperative BGCF 400 mg/L as cutoff point: group L < 400 mg/L and group H ≥400 mg/L. Receiver operating characteristic (ROC)curve was used to evaluate if intraoperative BGCF was a good index of postoperative outcomes. Results The area under the ROC curve of intraoperative BGC against prolonged ICU stay was 0. 804 (0.739-0. 869), against prolonged mechanical ventilation 0. 604 ( 0.415-0.793 ), against postoperative complications 0.801 ( 0.720-0. 882 )and against postoperative hospital stay 0.615 (0.523-0.707). The duration of ICU stay was significantly longer and the incidences of complications and prolonged postoperative hospital stay were higher in group H than in group L (P < 0.01). Conclusion Intraoperative BGCF is closely related to postoperative outcomes in patients after offpump CABG. The patients with the BGC≥400 mg/L has a poor prognosis.     

非体外循环冠状动脉旁路移植术患者术中血糖波动水平与短期预后的关系

Objective To investigate the effect of intraoperative fluctuation in blood glucose concentration (BGCF) on short-term clinical outcomes in patients after off-pump coronary artery bypass graft (CABG) .Methods Two hundred and fourteen ASA Ⅰ -Ⅲ patients ( NYHA grade Ⅰ -Ⅲ ) of both sexes aged 18-64 yr with body mass index 23-29 kg/m2 underwent elective off-pump CABG. Their left ventricular ejection fraction was ≥30% .Blood samples were obtained once an hour for determination of blood glucose concentration (BGC) between 10 min after induction of anesthesia and 10 min after closure of sternum. The maximum and minimum BGCs were record-ed . Intraoperative BGCF was defined as the difference between the maximum and minimum BGCs. Other factors which may influence clinical outcome were also recorded, including prolonged ICU stay ( ≥24 h), prolonged me-chanical ventilation ( ≥12 h) , postoperative complications (cardiac insufficiency secondary to operation, arrhyth-mia, myocardial infarction, respiratory insufficiency, stroke, infection, pleural effusion and surgical bleeding) and prolonged postoperative hospital stay ( ≥ 7 d) . The patients were divided into 2 groups using intraoperative BGCF 400 mg/L as cutoff point: group L < 400 mg/L and group H ≥400 mg/L. Receiver operating characteristic (ROC)curve was used to evaluate if intraoperative BGCF was a good index of postoperative outcomes. Results The area under the ROC curve of intraoperative BGC against prolonged ICU stay was 0. 804 (0.739-0. 869), against prolonged mechanical ventilation 0. 604 ( 0.415-0.793 ), against postoperative complications 0.801 ( 0.720-0. 882 )and against postoperative hospital stay 0.615 (0.523-0.707). The duration of ICU stay was significantly longer and the incidences of complications and prolonged postoperative hospital stay were higher in group H than in group L (P < 0.01). Conclusion Intraoperative BGCF is closely related to postoperative outcomes in patients after offpump CABG. The patients with the BGC≥400 mg/L has a poor prognosis.