Hemodynamics and coronary blood flow during exercise after coronary artery bypass grafting with internal mammary arteries in children with Kawasaki disease

BACKGROUND. Saphenous vein grafts (SVG) and internal mammary artery (IMA) grafts have been used for coronary artery bypass grafting. In adult patients with bypass grafting for atherosclerotic coronary artery disease, IMA grafts have been reported to have long-term patency; however, results are conflicting on whether the graft is sufficient to meet increased myocardial oxygen demand during exercise. There have been no studies on hemodynamics and blood flow during exercise after bypass grafting with IMA in pediatric patients with Kawasaki disease. METHODS AND RESULTS. We studied 17 pediatric patients with Kawasaki disease (average age, 7.5 +/- 3.1 years), who underwent coronary artery bypass grafting with the IMA. The average number of coronary artery bypass grafts was 2.1 +/- 0.7/patient. For all patients, the left IMA was anastomosed to the left anterior descending coronary artery; for eight patients, the right IMA was also anastomosed to the right coronary artery. In addition, 11 SVGs were used. The postoperative patency rates after 1 month were 100% with the IMA graft and 91% with SVG. One year after the operation, the patency rates were 100% with IMA and 50% with SVG. Hemodynamics during exercise were measured with a bicycle ergometer, and coronary sinus blood flow was measured by the continuous thermodilution method in six patients. The relation between delta LVEDP (the difference between left ventricular end-diastolic pressure at rest and during exercise) and delta SVI (the difference between the stroke volume index at rest and during exercise) was analyzed. Four of six patients had reduced cardiac function before operation (delta LVEDP, positive; delta SVI, negative). However, after the operation, all patients demonstrated improvements in cardiac function during exercise (delta LVEDP, positive; delta SVI, positive). Coronary sinus flow per left ventricular mass increased after operation from 70 +/- 46 to 87 +/- 56 ml/min at rest (p less than 0.05) and from 139 +/- 118 to 183 +/- 150 ml/min during exercise (p less than 0.05). CONCLUSIONS. In conclusion, this study reveals improvements in both hemodynamics and coronary blood flow during exercise after coronary artery bypass grafting with IMA grafts in pediatric patients with Kawasaki disease.     

Protective effect of aprotinin against lung damage in patients undergoing CABG surgery

OBJECTIVE: We investigated the protective effects of aprotinin, administered in the pulmonary artery, on lung damage after cardiopulmonary bypass (CPB). METHODS: A total of 20 patients undergoing elective coronary artery bypass grafting operations was included in the study and divided into two groups. In the aprotinin group (study group) (n = 10) the drug was administered in the pulmonary artery (15,000 KIU/min) via the pulmonary artery catheter. The control group (n = 10) received only placebo. Blood gas measurements, respiratory function tests, malondialdehyde (MDA), nitric oxide (NO), C4 and leukocyte counts were determined as parameters. Blood samples were taken before and after cross clamping. Lung biopsies were taken before and after CPB. RESULTS: In the aprotinin group, forced expiratory volume (FEV1) and paCO2 values were better than in the control group. The postclamping MDA value in the study group was 20.6 +/- 8.7 etamol/ml and in the control group 37.5 +/- 9.6 etamol/ ml. The post clamping NO value in the study group was 261.9 micromol/l and in the control group 147.20 +/- 27.6 micromol/l. C4 levels were found to be better in the study group than in the control group: reduced levels of C4 were found to be statistically significant (study group postclamping: 12.98 +/- 2.63 mg/dl vs. control group 20.6 +/- 11.81 mg/dl). The increase in leukocyte count was found to be statistically significant (12.63 +/- 3.83 x 10(3) vs. 7.27 +/- 1.72 x 10(3). The difference between the preoperative and postoperative FEV1 in the control group was statistically significant. A statistically significant difference was found in the postoperative FEV1 in both groups. CONCLUSION: Aprotinin administered in the pulmonary artery during CPB had a protective effect against lung damage after open-heart surgery.     

Intraoperative Flu?messung koronarer Bypassgef??e mit der Ultraschall-Transit-Zeit-Methode

The aim of the study was to compare the mean and maximum flow and the flow pattern of coronary vein grafts (SVG) supplying target vessels of the inferior and lateral wall with internal mammary (IMA) grafts to the left anterior descending artery (LAD). In 21 patients 25 bypass grafts (13/25 SVG, 12/25 IMA) were investigated. Using the transit time ultrasound method, flow was measured every 5 ms and the flow data of 60 s were acquired. The flow pattern showed significant differences between both graft types during their cycle. IMA grafts showed only one peak occurring after 22.1+/-12.3% and the second after 63.4+/-15.5% of their cycle. The mean flow was not different in both graft types (IMA: 45.3+/-27.0 ml/min and SVG: 41.8+/-26.7 ml/min, p = n. s.) as it was the case for the maximum flow (IMS: 98. 4+/-45.2 ml/min and SVG: 75.7+/-55.4 ml/min, p = n. s.). In conclusion, there is a different flow pattern for both graft types concerning the number and the occurrence of flow-peaks in the bypass cycle. The mean and peak flow showed no significant difference.     

Beating heart versus conventional reoperative coronary artery bypass surgery

BACKGROUND: The incidence of reoperative coronary artery bypass grafting is increasing with an increase in the number of patients undergoing coronary artery bypass surgery. The clinical outcome of redo coronary artery bypass grafting without cardiopulmonary bypass and conventional coronary artery bypass grafting using cardiopulmonary bypass are different. METHODS AND RESULTS: We compared clinical parameters in patients who underwent off-pump (n=156) versus on-pump (n=194) redo coronary artery bypass grafting performed between January 1995 and December 2001 in our institute, to determine if off-pump surgery has improved the surgical outcome of redo coronary artery bypass grafting and emerged as an ideal technique. Patients who underwent on-pump redo surgery required more postoperative blood transfusion (86.53% on-pump v. 12.82% off-pump. p=0.001), prolonged ventilatory support (>24 hours) (16.49% on-pump v. 7.7% off-pump, p=0.021) and higher inotropic support (23.71% on-pump v. 10.89% off-pump, p=0.003). On-pump redo coronary artery bypass grafting was also associated with a prolonged stay in the intensive care unit (40+/-6.2 hours on-pump v. 20+/-4.1 hours off-pump, p=0.001) and longer hospital stay (9+/-4.2 days on-pump v. 5+/-3.4 days off-pump, p=0.001). In-hospital mortality was higher in on-pump patients than in off-pump ones (7.7% v. 3.2%); however, this was not statistically significant (p=0.114). CONCLUSIONS: Off-pump redo coronary artery bypass grafting is a safe method of myocardial revascularization with lower operative morbidity and mortality, less requirement of blood products and early hospital discharge, compared with conventional on-pump redo coronary artery bypass grafting.     

Do changes in blood flow in the subclavian artery affect flow volume in IMA grafts after complete arterial revascularization with the T-graft technique?

BACKGROUND: The T-graft procedure achieves complete arterial coronary revascularization with only two conduits. In this technique, all the bypass anastomoses are supplied by the left internal mammary artery (IMA). Changes in flow conditions or flow redistribution in the subclavian artery may thus sigificantly influence coronary perfusion. The objective of this study was to determine whether changes in blood flow in the subclavian artery affect the flow in IMA grafts in patients who have undergone complete arterial revascularization with T-grafts. METHODS: Quantitative flow volume and flow profiles in the IMA graft and the proximal subclavian artery were measured with a flow-wire in 20 patients one week postoperatively. Following baseline measurements, brachial artery constriction was achieved by applying a blood pressure measurement cuff to the patient's left upper arm. After 5 minutes, quantitative flow in the IMA and in the proximal subclavian artery was assessed. The cuff was then released and the measurements repeated. RESULTS: Flow in the subclavian artery changed significantly (p < 0.01) from baseline (355.4 +/- 95.2 ml/ min) to constriction (171.2 +/- 61.3 ml/min) and hyperemia (679.3 +/- 195.1 ml/min). Flow in the IMA graft remained constant irrespective of subclavian artery flow (75.4 +/- 26.2 ml/min vs. 78.0 +/- 28.9 ml/min vs. 75.5 +/- 29.3 ml/min, respectively). The flow profile in the IMA was similarily unchanged. CONCLUSION: In patients in whom the coronary bypass blood flow is dependent on the left IMA, neither the quantitative flow volume nor the flow profile are altered by changes in blood flow of the subclavian artery.     

Coronary artery bypass grafting by utilizing the internal mammary artery graft in 100 Japanese patients

The internal mammary artery (IMA) grafting for myocardial revascularization was performed in 100 Japanese patients during a three-year period. There were 86 males and 14 females with the mean age of 58 +/- 9 (37 approximately 75 year-old). Unilateral IMA was used in 88 patients and bilateral IMA was used in 12 patients. Sequential IMA grafting was performed in 5 patients. The sites of IMA grafting were 91 left anterior descending arteries (LAD), 16 diagonal branches, 8 circumflex arteries and 2 right coronary arteries. Saphenous vein or gastroepiploic artery was concomitantly used to bypass the other coronary arteries in 90 patients. The number of distal anastomosis ranged from 1 to 6 and the mean was 2.8 per patient. Two patients died within 30 days and one patient died at 3 months after surgery. Perioperative myocardial infarction was noted in 3 patients. Symptomatic relief was obtained in 94 (97%) of 97 survivors. The patency of the IMA graft at mean 2.2 postoperative months was 97% (58/60) in LAD, 100% (14/14) in the diagonal branch, 100% (5/5) in the circumflex artery, 100% (1/1) in the right coronary artery, and 98% (78/80) in over-all grafted coronary arteries. Pre- and postoperative exercise thallium scintigraphy in 13 patients, who received the IMA graft to severely stenosed LAD, showed significant improvement of the washout ratio (from 33.1 +/- 16.9% to 47.4 +/- 14.8%) which was nearly equivalent to that of the saphenous vein graft to LAD (from 24.8 +/- 6.2% to 48.1 +/- 6.6%, n = 7).(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiovascular and adenylate cyclase stimulating effects of colforsin daropate, a water-soluble forskolin derivative, compared with those of isoproterenol, dopamine and dobutamine.

Colforsin daropate is a recently developed water-soluble derivative of forskolin that directly stimulates adenylate cyclase, unlike the catecholamines. The chronotropic, inotropic and coronary vasodilator actions of colforsin daropate were compared with those of isoproterenol, dopamine and dobutamine, using canine isolated, blood-perfused heart preparations. The stimulating effect of each drug on adenylate cyclase activity was also assessed. Colforsin daropate, as well as each of the catecholamines, exerted positive chronotropic, inotropic and coronary vasodilator actions. The order of selectivity for the cardiovascular variables of colforsin daropate was coronary vasodilation > positive inotropy > positive chronotropy; whereas that of isoproterenol, dopamine and dobutamine was positive inotropy > coronary vasodilation > positive chronotropy. Thus, a marked characteristic of colforsin daropate is its potent coronary vasodilator action. On the other hand, each drug significantly increased the adenylate cyclase activity in a dose-related manner: colforsin daropate > isoproterenol > dopamine = dobutamine. These results suggest that colforsin daropate may be preferable in the treatment of severe heart failure where the coronary blood flow is reduced and beta-adrenoceptor-dependent signal transduction pathway is down-regulated.     

Cardiopulmonary bypass impairs left ventricular function determined by conductance catheter measurement

OBJECTIVE: Postoperative cardiac depression is attributed to ischemia and the effects of cardiopulmonary bypass (CPB). To evaluate the effect of CPB alone on postoperative left ventricular (LV) dysfunction, we used a conductance catheter to determine the LV performance by pressure-volume relation before and after CPB. METHODS: Twenty-two 3-week-old piglets underwent sternotomy and normothermic CPB for one hour. A conductance catheter was placed in the LV cavity. End-systolic pressure-volume relationships (ESPVR), left ventricular end-diastolic pressure (LVEDP) and systemic vascular resistance (SVR) were measured under steady-state conditions before and 15 min after weaning from CPB in group A (n = 11). Group B included 11 piglets without CPB and served as control. RESULTS: There was no difference between groups before initiating CPB. As an indication of depressed LV function, the ESPVR slope (mmHg/ml) was significantly lower in group A after weaning from CPB than in group B (1.69 +/- 0.5 vs. 1.86 +/- 0.55; p = 0.008). In group A, peak dP/dt (max index) (mmHg/s/m (2)) decreased markedly (1596 +/- 339 vs. 2045 +/- 206; p = 0.03), while LVEDP (mmHg) was significantly increased (11.7 +/- 2.6 vs. 5.4 +/- 0.9; p < 0.0001). In addition, SVR (index) (dyn x s x cm (-5)/m (2)) in group A was significantly lower (1407 +/- 176 vs. 1677 +/- 313; p < 0.0001) than in group B. CONCLUSION: Using the very sensitive conductance catheter technique in a pig model, we could show that CPB leads to a significant depression of LV contractility and elastance even without ischemic arrest.     

Impact of hematocrit value after coronary artery surgery on perioperative myocardial infarction rate

BACKGROUND: The optimal hematocrit (HCT) value after coronary artery bypass grafting on cardiopulmonary bypass (CPB) has not yet been established. The purpose of our retrospective study was to investigate the association between HCr at the time of entry into the ICU and perioperative Ml rate. METHODS: We reviewed the charts of 500 consecutive coronary artery surgery patients with respect to biometric data, operative procedure, aprotinin or tranexamic acid use, perioperative drainage blood loss and transfusion requirements, perioperative Ml, ICU stay and hospital mortality. Perioperative Ml was defined as new Q-wave on ECG and CK-MB 250U/I. Patients were categorized into three groups depending on their HCr value at the time of entry into the ICU: low (HCTcu 27%): medium (HCr,cu 28% to 32%); high(HCTrcu > or =33%). RESULTS: Age, gender distribution, preoperative LV function, and previous Ml rate were similar between the three groups. Low HCT patients (n -133) received 3.1 +/- 1.0 (Mean + SD) grafts during 55 +/- 19 minutes aortic cross clamp time, 98 +/- 31 minutes on CPB (medium HCT: n = 257; 3.2 +/- 1.0 grafts, 51 +/- 20 min cross clamp time, 93 +/- 30 min CPB; p - 0.45 vs. low HCT; high HCT: n = 110: 3.3 +/- 1:0 grafts; 53 +/- 20 min cross clamp time; 104 +/- 38 min CPB; p = 0.02 vs. medium HCT). The perioperative Ml rate was 3.8% in the low, 4.3% in the medium, and 6.4% in the high-HCr group (p =0.59 ). Intraoperative red blood cell and fresh frozen plasma transfusions were similar between the groups. In the low-HCa group, 53.4% of the patients received aprotinin during the procedure (medium HCa: 65.4%; high HCT: 77.3%; p<0.001). Drainage blood loss during the first 24 hours on ICU was 834 +/- 453 ml in the low, 757 +/- 485 ml in the medium (p -0.44 vs. low), and 640 +/- 353 ml in the high-HCr group (p = 0.003 vs. low). Postoperative red blood cell and fresh frozen plasma transfusions were highest in the low-HCa group(p<0.001). ICU stay was similar between the groups. Hospital mortality was 0.75% in the low, 1.9% in the medium, and 4.5%in the high-HCa group (p = 0.12). CONCLUSIONS: In this retrospective analysis of 500 consecutive coronary artery surgery patients, we did not find any association between perioperative Ml rate and HCr value on entry into the ICU. These results do not support the recent suggestion that low HCT at the time of entry into the ICU protects against perioperative Ml.     

Does off-pump coronary revascularization reduce the release of the cerebral markers, S-100beta and NSE?

OBJECTIVES: The aims of this study were to (1) compare the release of S-100 beta and NSE in off-pump coronary artery bypass grafting (CABG) versus on-pump surgery; (2) investigate whether the S-100 beta and NSE serum concentrations correlate with cardiopulmonary bypass (CPB) duration. MATERIALS AND METHODS: Between October 2002 and May 2004, 42 patients undergoing first time CABG surgery were enrolled in the study. The exclusion criteria were: LVEF<35%, age>70 years, previous myocardial infarction, REDO surgery, the presence of valvular heart disease and/or cerebrovascular disease, abnormal preoperative carotid vessels angiography, coronary artery disease involving the distal circumflex artery, renal dysfunction, coagulopathy. The patients were randomly assigned either to undergo on-pump CABG surgery [group I, n=24 patients] or off-pump CABG [group II, n=18 patients]. Blood was not re-transfused from the cardiotomy suction. All patients presenting haemolysis were excluded from the study. RESULTS: The preoperative S-100beta was 0.13+/-0.08 (microg/l) and NSE 7+/-1.5 (microg/l) in group I and 0.12+/-0.1 (microg/l) and 6.9+/-2.7 (microg/l), respectively in group II. Six hours after the surgery, S-100beta in patients of group I reached a maximum level of 1.38+/-0.4 (microg/l) and NSE of 17.7+/-6.5 (microg/l) compared to 0.5+/-0.11 (microg/l) [S-100B] and NSE 8.6+/-4.2 (microg/l) in group II (p=0.001). Three (12%) patients in group I and none (0%) in group II suffered postoperative delirium, p=0.247. No strokes occurred linear regression analysis revealed a strong correlation between cardiopulmonary bypass duration and S-100beta and NSE peak levels, p<0.0021 (r(2)=0.36) and p<0.0001 (r=0.81), respectively. CONCLUSION: Coronary artery bypass surgery with CPB causes a significantly greater increase in NSE and S-100beta serum levels than off-pump surgery and correlates with CPB duration.     

Pulmonary outcomes of off-pump vs on-pump coronary artery bypass surgery in a randomized trial

STUDY OBJECTIVES: Comparison of pulmonary outcomes after off-pump coronary artery bypass (OPCAB) vs on-pump coronary artery grafting with cardiopulmonary bypass (CABG/CPB).Study design: We examined preoperative and postoperative respiratory compliance, fluid balance, hemodynamics, arterial blood gases, chest radiographs, spirometry, pulmonary complications, and time to extubation in a prospective trial of 200 patients randomized to OPCAB vs CABG/CPB performed by one surgeon. RESULTS: One CABG/CPB patient and two OPCAB patients required mitral valve repair or replacement and were withdrawn. After three crossovers from CABG/CBP to OPCAB and one crossover from OPCAB to CABG, 97 CABG/CPB patients and 100 OPCAB patients remained. There were no significant preoperative demographic differences between groups. Postoperative compliance was reduced more after OPCAB than after CABG/CPB (- 15.4 +/- 10.7 mL/cm H(2)O vs - 11.2 +/- 10.1 mL/cm H(2)O [mean +/- SD]; p = 0.007), associated with rotation of the heart into the right chest to perform posterolateral bypasses (p < 0.001) and the concomitant increased fluid requirements necessary to maintain hemodynamic stability during rotation of the heart. In addition to higher intraoperative fluid intake (4,541 +/- 1,311 mL vs 3,585 +/- 1,033 mL, p < 0.0001), OPCAB patients had higher intraoperative fluid balance (3,903 +/- 1,315 mL vs 1,772 +/- 1,373 mL, p < 0.0001), and higher postoperative pulmonary arterial diastolic pressure (15.0 +/- 5.5 mm Hg vs 11.8 +/- 5.2 mm Hg, p < 0.0001) and central venous pressure (10.4 +/- 4.5 mm Hg vs 8.4 +/- 4.7 mm Hg, p < 0.0001). Despite lower compliance, immediate postoperative Pao(2) on fraction of inspired oxygen of 1.0 (275 +/- 97 torr vs 221 +/- 92 torr, p = 0.001) was higher after OPCAB and extubation was earlier (p = 0.001). Postoperative chest radiographs, spirometry, mortality, reintubation, or readmission for pulmonary complications were not different between groups. CONCLUSIONS: Compared to CABG/CPB, OPCAB was associated with a greater reduction in postoperative respiratory compliance associated with increased fluid administration and rotation of the heart into the right chest to perform posterolateral grafts. OPCAB yielded better gas exchange and earlier extubation but no difference in chest radiographs, spirometry, or rates of death, pneumonia, pleural effusion, or pulmonary edema.     

Evaluation of Right Ventricular Function During CABG: Transesophageal Echocardiographic Assessment of Hepatic Venous Flow Versus Conventional Right Ventricular Performance Indices

The vulnerability of right ventricle (RV) to ischemic insult during cardiac surgery is being increasingly recognized. This study aims to evaluate right ventricular function by measuring hepatic venous flow (HVF) patterns using intraoperative transesophageal echocardiography (TEE), and to compare HVF with other conventional two-dimensional echocardiographic and hemodynamic indices of RV performance. Patients undergoing coronary artery bypass grafting (CABG) were studied intraoperatively using a multiplane dual frequency 5/3.7-MHz phased array transducer, a pulmonary artery catheter, and an arterial catheter. Peak velocities and time velocity integrals of HVF pattern were studied. Peak systolic-diastolic ratio (S/D) of biphasic HVF and reverse flow ratio (% reverse flow/forward flow = % RF/FF) were also examined. Two-dimensional echocardiographic measurements included: (1) transverse plane long-axis (LA) and short-axis (SA) planimetered areas expressed as ratios; LA maximum major and minor-axis shortening fractions; (2) tricuspid annular plane systolic excursion (TAPSE) ratio. All data were obtained after induction of anesthesia (stage 1), after sternotomy (stage 2), aftercardiopulmonary bypass (CPB) (stage 3), and after sternal closure (stage 4). Pre-CPB all 35 patients had biphasic HVF by Doppler. In 31 patients peak S/D ratio was >1. After CPB, there was significant reduction in systolic forward flow (S wave), along with an increase in late systolic reverse flow (V wave) and an increase in % RF/FF. At this stage TAPSE ratio decreased (pre CPB 0.33 +/- 0.12 vs post CPB 0.30 +/- 0.11). There was simultaneous decrease in 2-D long-axis LA (pre CPB 0.52 +/- 0.11 vs post CPB 0.31 +/- 0.01) and max major axis LA (pre CPB 0.38 +/- 0.06 vs post CPB 0.31 +/- 0.11). Max major axis LA correlated significantly with changes in right atrial pressure (P < 0.05). Tricuspid annular motion diminished significantly at sternal closure. Hepatic systolic forward flow and TAPSE ratio can be an indirect measure of RV systolic functions in correlation with maximum major axis LA changes. Evaluation of HVF provides unique insight into right ventricular dynamics. It is an easy, safe, and sensitive method for assessing RV functions intraoperatively.     

Evidence for inflammatory responses of the lungs during coronary artery bypass grafting with cardiopulmonary bypass

OBJECTIVE: The occurrence of a systemic inflammatory reaction during cardiac surgery with cardiopulmonary bypass (CPB) has been well established, and the heart itself has been shown to release inflammatory mediators after ischemia. The hypothesis of the present study was that the lungs are also a site of inflammatory responses during early reperfusion. METHODS: In 20 consecutive patients undergoing coronary artery bypass grafting, blood was simultaneously drawn from the right atrium (RA) and the pulmonary vein (PV) before CPB and at 1 min, 10 min, and 20 min of reperfusion. The levels of interleukin (IL)-6, IL-8, IL-10, and tumor necrosis factor (TNF)-alpha were determined, as well as the adhesion molecules CD41 and CD62 on platelets and CD11b and CD41 on leukocytes. As a measure of the pulmonary release, ratios of PV and RA levels were calculated. RESULTS: Before CPB, the concentrations of cytokines tended to be lower in the PV compared with the RA. At 1 min of reperfusion, no significant concentration increases were found in the PV. At 10 min of reperfusion, the PV/RA ratio (mean +/- SEM) for IL-6 was 2.06 +/- 0.37 and 1.24 +/- 0.15 for IL-8 (p = 0.02 and p = 0.04, respectively, compared with the pre-CPB ratios of 0.89 +/- 0.4 and 0.99 +/- 0.2). At 20 min of reperfusion, PV/RA ratios for IL-6 (1.95 +/- 0.37) and IL-10 (0.99 +/- 0.4) were higher than before CPB (0.89 +/- 0.04, p = 0.05 and 0.85 +/- 0.06, p = 0.03, respectively). Adhesion molecule counts on platelets and polymorphonuclear neutrophils (PMNs) tended to be higher in the PV than in the RA before CPB. At 1 min of reperfusion, the PV/RA ratio of CD41 on monocytes (0.89 +/- 0.04) and of CD41 on PMNs (1.05 +/- 0.05) was less than before CPB (1.24 +/- 0.08, p = 0.0002 and 1.55 +/- 0.14, p = 0.0002). At 10 min and 20 min of reperfusion, similar changes were found. CONCLUSIONS: The observed changes indicate an inflammatory response of the lungs. Proinflammatory cytokines are increased in pulmonary venous blood. At the same time, activated blood cells are retained in the pulmonary circulation. This may contribute to pulmonary dysfunction almost routinely observed after CPB.     

不同部位的人体冠状动脉搭桥材料血管释放一氧化氮和内皮超极化因子差异的实验研究

目的:本研究通过直接检测人体乳内动脉(IMA)、大隐静脉(SV)与桡动脉(RA)内皮细胞释放的一氧化氮(NO)浓度以及平滑肌细胞膜电位信号,对比不同部位的人体冠状动脉搭桥材料血管释放一氧化氮和内皮超极化因子(EDHF)的差异.方法:将冠状动脉搭桥手术(CABG)常用的不同部位搭桥材料血管分为4组:乳内动脉组(n=15)、桡动脉组(n=6)、大隐静脉组(n=23),以及压力扩张后的大隐静脉组[简称PV组,n=9,将肝素生理盐水注入大隐静脉管腔,压力维持在100～600 mmHg(1 mmHg=0.133 kPa)].分别将长度为5 mm的血管片放置于37℃血管灌流室中,加入乙酰胆碱(log M-8~log M-5)和缓激肽(log M-10~log M-7),以激发内皮细胞释放一氧化氮与EDHF.应用一氧化氮测定仪与膜电位记录仪,直接检测桥血管释放的一氧化氮与平滑肌细胞膜电位信号,研究其一氧化氮释放动力学与EDHF介导的超极化反应.结果:①一氧化氮基础释放浓度:乳内动脉组显著高于大隐静脉组与桡动脉组;而桡动脉组的一氧化氮基础释放水平明显高于大隐静脉组.②在乙酰胆碱的激发下,乳内动脉组释放的一氧化氮总量明显超过桡动脉组和大隐静脉组;在缓激肽(log M-8、log M-7)的激发下,乳内动脉组和大隐静脉组均较桡动脉组升高.③PV组一氧化氮的基础释放与刺激性释放均显著减少.④乳内动脉组由EDHF调节的平滑肌细胞超极化幅度明显高于大隐静脉组与桡动脉组.桡动脉组与大隐静脉组相比,由乙酰胆碱激发、EDHF介导的平滑肌细胞超极化幅值亦明显增高,差异均有统计学意义(P<0.05~0.01).结论:①从内皮细胞一氧化氮与EDRF介导的内皮细胞功能角度评价,乳内动脉最佳,而桡动脉明显优于大隐静脉;②压力扩张会损害大隐静脉一氧化氮介导内皮细胞功能,导致大隐静脉桥远期通畅率低下.     

Cardiopulmonary bypass copolymer surface modification reduces neither blood loss nor transfusions in coronary artery surgery

OBJECTIVE: Surface-modifying additives (SMA) have been suggested for improving cardiopulmonary bypass (CPB) circuit biocompatibility, potentially minimizing inflammatory complications and bleeding associated with CPB. The purpose of this prospective, randomized clinical study was to compare a novel copolymer surface-modified CPB circuit (SMARXT; COBE Cardiovascular) against the unmodified circuit. METHODS: We randomized 122 patients with isolated coronary artery disease subjected to first-time surgery on CPB into either the SMA (n = 62) or the control group (n = 60). Exclusion criteria included renal insufficiency, liver disease, coagulopathy, anticoagulation therapy < 6 days preop, carotid artery stenosis > 70 %, and a history of stroke. We collected perioperative clinical data including drainage blood loss, transfusion requirements, duration of mechanical ventilation, and ICU stay. Platelet function was determined pre- and post-CPB. RESULTS: SMA patients received 3.2 +/- 0.9 (SD) grafts during 48 +/- 16 min of aortic cross clamp and 91 +/- 30 min CPB (Control: 3.0 +/- 0.9 grafts; p = 0.33, 46 +/- 14 min AXC; p = 0.36, and 84 +/- 23 min CPB; p = 0.14). In the SMA group, 23 patients (37 %) received red blood-cell transfusions, 9 patients (15 %) fresh frozen plasma, and 3 patients (5 %) received platelets (control: n = 27 [46 %], p = 0.44; n = 10 [17 %], p = 0.91; and n=4 [7 %], p = 0.71, respectively). Platelet count on CPB fell to the same level in both groups. In SMA patients, platelet function decreased from 94.2 +/- 24.9 % pre-CPB to 79.5 +/- 32.8 % post-CPB (p = 0.043) (control: from 87.7 +/- 25.6 % to 69.4 +/- 34.7 %; p = 0.001). Postoperative drainage blood loss, mechanical ventilation duration, and ICU stay were similar in both groups (p > 0.3). One patient of the control group was excluded due to surgical bleeding, and one SMA patient died. CONCLUSIONS: Our results show that the surface-modified CPB circuit decreased neither blood loss nor transfusions despite slightly better platelet function preservation compared to the unmodified circuit. This type of CPB circuit surface modification does not appear to improve clinical outcome in low-risk coronary artery surgery patients.     

Glucose homeostasis. Comparison between hypothermic and normothermic cardiopulmonary bypass.

STUDY OBJECTIVE: Disturbance in blood glucose homeostasis during cardiac surgery may cause visceral and metabolic alterations. Hypothermic CPB induces glucose and hormonal changes. As normothermic CPB is used at some institutions, a comparison of blood glucose and plasma hormones between hypothermic and normothermic CPB was performed. DESIGN: Prospective nonrandomized study. SETTING: University cardiac center. PATIENTS: Twenty-two nondiabetic adults undergoing elective coronary bypass and/or valvular surgery. INTERVENTIONS: Group 1 (n = 12) underwent hypothermic CPB (25 degrees C) and group 2 (n = 10) normothermic CPB (37 degrees C). In both groups nonpulsatile CPB was achieved with a membrane oxygenator and dextrose-free crystalloid priming. Dextrose was not administered during surgery but was infused postoperatively (125 mg/kg/h). MEASUREMENTS AND RESULTS: Eight blood samples were drawn during the period of arrival in the operating room (control) to the third postoperative hour. During hypothermic CPB in group 1, blood glucose level increased to 154 +/- 20 mg/dl (mean +/- SD) associated with a decrease in plasma insulin and an increase in epinephrine, despite a decrease in cortisol and growth hormone. During rewarming, the blood glucose value continued to increase (to 197 +/- 35 mg/dl) associated with an increase in glucagon, growth hormone and catecholamines, despite a 374 percent increase in insulin. During CPB in group 2, insulin, glucagon, cortisol and catecholamines were significantly higher than during hypothermic CPB so that the blood glucose level was not significantly different between the two groups during CPB. Blood glucose value was higher in group 1 than in group 2 at closure of the chest (208 +/- 30 vs 175 +/- 19 mg/dl, respectively, p less than 0.02) and at the third postoperative hour (271 +/- 30 vs 221 +/- 51 mg/dl, p less than 0.01). In both groups, however, the postoperative increase in blood glucose was accompanied by a similar increase in insulin, cortisol and catecholamines but glucagon was lower after hypothermic CPB. CONCLUSIONS: Hyperglycemia occurred perioperatively in cardiac surgery with dextrose-free priming both during hypothermic and normothermic CPB but normothermic CPB resulted in a slow and steady increase in both glucose and insulin concentrations without the major perturbations that occurred with hypothermic CPB. Postoperatively, higher blood glucose was observed in the hypothermic CPB group.     

Effects of preoperative statin therapy on cytokines after cardiac surgery

INTRODUCTION: In addition to their lipid-lowering action, it has been demonstrated that statins can exert direct anti-inflammatory effects. We investigated the effect of preoperative statin therapy on systemic inflammatory markers and myocardial NF-kappaB inhibitor IkappaB-alpha after cardiac surgery. METHODS: Thirty-six patients undergoing elective coronary artery bypass grafting with cardiopulmonary bypass (CPB) with cardioplegia were divided into two groups (statin group, n = 18; control group, n = 18). Plasma concentrations of pro-inflammatory cytokines (tumor necrosis factor alpha [TNFalpha], interleukin [IL]-6, IL-8) and anti-inflammatory IL-10 were measured before and 1, 4, 10, and 24 hours (h) after CPB. Phosphorylated IkappaB-alpha/total IkappaB-alpha ratio was assessed before and after CPB in right atrial biopsies. RESULTS: Baseline and operative data did not differ between groups. Statin therapy was associated with lower preoperative low-density lipoprotein levels compared to control (73+/-6 vs. 92+/-6 mg/dL; P=0.03). Release of IL-6 was attenuated in the statin group at 4 h (2270+/-599 vs. 5120+/-656 pg/ml; P<0.01) and 10 h (1295+/-445 vs. 3116+/-487 pg/ml; P<0.05) compared to the control group. IL-10 increased after surgery in both groups (P<0.05), but was higher in the statin group at 1 h (66+/-15 vs. 26+/-16 pg/mL; P<0.01). Phosphorylated IkappaB-alpha/total IkappaB-alpha ratio before CPB did not differ between groups, but was elevated after CPB in both groups (P<0.05), indicating enhanced degradation of IkappaB-alpha. Statin therapy had no effect on TNFalpha and IL-8. CONCLUSIONS: Preoperative statin therapy attenuates the release of pro-inflammatory IL-6 and up-regulates anti-inflammatory IL-10 after cardiac surgery with cardioplegia, but fails to inhibit phosphorylation of myocardial IkappaB-alpha.     

Effects of perioperative nesiritide in patients with left ventricular dysfunction undergoing cardiac surgery:the NAPA Trial.

OBJECTIVES: The purpose of this study was to determine the role nesiritide might play in patients with left ventricular dysfunction undergoing coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB). BACKGROUND: Given the hemodynamic, neurohormonal, and renal effects of natriuretic peptides, nesiritide might be useful in the management of patients undergoing cardiac surgery. METHODS: This prospective, double-blind, exploratory evaluation randomly assigned patients with ejection fraction 相似文献   

不同剂量盐酸戊乙奎醚对体外循环冠脉搭桥手术患者心肌保护作用

目的 比较两种不同剂量盐酸戊乙奎醚对体外循环下行冠脉搭桥手术患者心肌保护作用.方法 2011年5月至2013年5月择期行冠脉搭桥手术患者75例,随机分成3组：对照组（25例）,给予等量生理盐水;小剂量组（25例）,戊乙奎醚 0.05 mg/kg;大剂量组（25例）,戊乙奎醚0.1 mg/kg.比较三组冠脉搭桥手术患者不同时间点的心肌肌钙蛋白I（cTnI）、肌酸磷酸激酶同工酶MB（CK-MB）、肌酸激酶（CK）、谷草转氨酶（AST）、α-羟丁酸脱氢酶（α-HBDH）、乳酸脱氢酶（LDH）浓度的变化.结果 三组患者cTnI、CK-MB、CK、AST、α-HBDH、LDH浓度,主动脉开放后1 h（T1）及主动脉开放后24 h（T2）与麻醉诱导前（T0）相比明显升高,差异均有统计学意义（P〈0.05）;T1、T2时间点组间比较,戊乙奎醚大、小剂量组低于对照组,差异有统计学意义（P〈0.05）,戊乙奎醚大剂量组与小剂量组相比差异无统计学意义（P＆gt;0.05）.结论 盐酸戊乙奎醚对体外循环冠脉搭桥手术患者具有心肌保护作用,安全性好,值得临床推广和应用,剂量上大剂量组并不优于小剂量组.     

Uncontrolled reoxygenation by initiating cardiopulmonary bypass is associated with higher protein S100 in cyanotic versus acyanotic patients

BACKGROUND: The systemic reoxygenation injury produced by initiating cardiopulmonary bypass (CPB) in infants with cyanotic heart disease may be associated with cerebral dysfunction and injury. Increased protein S100 (S100) serum levels may indicate cerebral and blood brain barrier damage as well as inflammatory changes, therefore serving to quantify these changes. The present clinical study assessed S100 in cyanotic patients undergoing CPB with normoxic versus hyperoxic paO2 in acyanotic cases and in controls without CPB. METHODS: 43 patients with congenital heart disease aged 5 days to 15 years (mean 4.4 years) were enrolled consecutively and divided in four groups: (1) Cyanotic infants undergoing controlled normoxic reoxygenation on CPB (n = 12), (2) cyanotic infants undergoing uncontrolled hyperoxic reoxygenation on CPB (n = 9), (3) acyanotic infants operated with CPB (n = 16) and (4) patients operated without CPB (n = 6). Blood samples were collected after induction of anesthesia (A), up to 4 hours after surgery (B) and at postoperative day one (C). RESULTS: Preoperative S100 serum levels [microg/l] in all groups were below clinical relevance. S100 increased markedly after surgery in groups 1 and 2. Differences in postoperative S100 levels were significant between groups 1 (0.45 +/- 0.13) and 3 (0.35 +/- 0.09; p = 0.018), between groups 2 (1.41 +/- 0.47) and 3 (p = 0.01), and between groups 2 and 4 (0.29 +/- 0.09; p = 0.045). There were no significant differences in postoperative S100 levels (B) between groups 1 and 2 (p = 0.05), groups 1 and 4 (p = 0.05), or groups 3 and 4 (p = 0.93). CONCLUSION: Uncontrolled hyperoxic reoxygenation on CPB for surgical correction of congenital heart defects is associated with higher S100 levels in cyanotic infants as compared to acyanotic patients undergoing comparable operations.