Avoiding cardiopulmonary bypass in multivessel CABG reduces cytokine response and myocardial injury

Strategies to attenuate maladaptive inflammatory response associated with cardiopulmonary bypass

Cardiopulmonary bypass (CPB) initiates an intense inflammatory response due to various factors: conversion from pulsatile to laminar flow, cold cardioplegia, surgical trauma, endotoxemia, ischemia-reperfusion injury, oxidative stress, hypothermia, and contact activation of cells by the extracorporeal circuit. Redundant and overlapping inflammatory cascades amplify the initial response to produce a systemic inflammatory response, heightened by coincident activation of coagulation and fibrinolytic pathways. When unchecked, this inflammatory response can become maladaptive and lead to serious postoperative complications. Concerted research efforts have been made to identify technical refinements and pharmacologic interventions that appropriately attenuate the inflammatory response and ultimately translate to improved clinical outcomes. Surface modification of the extracorporeal circuit to increase biocompatibility, miniaturized circuits with sheer resistance, filtration techniques, and minimally invasive approaches have improved clinical outcomes in specific populations. Pharmacologic adjuncts, including aprotinin, steroids, monoclonal antibodies, and free radical scavengers, show real promise. A multimodal approach incorporating technical, circuit-specific, and pharmacologic strategies will likely yield maximal clinical benefit.

Antioxidant activity in off and on-pump coronary artery bypass grafting and valve replacement surgery

OBJECTIVES

Cardiac surgeries initiate oxidative stress, increasing organ dysfunction development and mortality. The present study investigated the superoxide dismutase (SOD) activity, as an antioxidant enzyme, in patients undergoing coronary artery bypass (CABG) and heart valve replacement surgeries.

METHODS

A prospective study was performed on patients with proven coronary artery disease (CAD) or valvular heart disease (VHD) candidates for on- or off-pump CABG and valve replacement surgery. Serum SOD activity was measured preoperatively, at 24 h postoperatively, and at the time of discharge. In addition, echocardiography was performed before surgery and at discharge.

RESULTS

A total of 48, 51, and 47 patients were enrolled in the on-pump, off-pump CABG, and valve replacement groups, respectively. Baseline serum SOD activity showed no significant association with BMI, age, and blood pressure in either CAD or VHD patients. The SOD values decreased at the 24 h postoperative time and then increased at the time of discharge in all groups, except for a slight decrease in the on-pump group. The changes in serum SOD values were not significantly different for the three surgical groups.

CONCLUSIONS

The serum SOD activities fell significantly after CABG and valve replacement surgery. Further investigation is emphasized for the role of SOD in oxidative stress after cardiac surgery.

Changes in serum zinc and copper concentrations in patients with cardiovascular disease following cardiac surgery

The trace elements copper (Cu) and zinc (Zn) are essential for maintaining oxidative balance, and cardiac surgery is known to provoke an increase in oxidative stress. We investigated the variations in serum Zn and Cu concentrations before and after surgery in patients undergoing on- and off-pump CABG and heart valve replacement. We performed a prospective study on patients undergoing on- or off-pump CABG, or heart valve replacement surgery (48, 51, and 47 patients, respectively). Venous blood samples were obtained, and serum Cu and Zn concentrations were measured preoperatively, 24 h postoperatively, and the time of discharge. In addition, echocardiography was carried out on all patients before surgery and again on the day of discharge. We found the temporal changes in Cu, Zn, and Zn/Cu ratio were significantly different in all three groups of surgery (p < 0.05). In each group, Cu and Zn values and Zn/Cu ratio decreased at the 24-h postoperative time and rose at the discharge time. There were no significant differences between surgery groups in the changes induced in Zn or Cu values (p > 0.05). In conclusion, the concentrations of Cu and Zn were markedly reduced after on- and off-pump CABG and valve replacement surgery. This may suggest that supplementary Zn and Cu administration could be beneficial during open-heart surgeries. However, more long-term studies with more patients are needed to confirm this hypothesis.

Diagnostic and Prognostic Value of miRNAs after Coronary Artery Bypass Grafting: A Review

MiRNAs are noncoding, 21-24 nucleotide-long RNA particles that control over 60% of genes. MiRNAs affect gene expression through binding to the 3'-untranslated region of messenger RNA (mRNA), thus inhibiting mRNA translation or inducing mRNA degradation. MiRNAs have been associated with various cardiovascular diseases, including heart failure, hypertension, left ventricular hypertrophy, or ischemic heart disease. In addition, miRNA expression alters during coronary artery bypass grafting (CABG) surgery, which could be used to predict perioperative outcomes. CABG is an operation in which complex coronary arteries stenosis is treated by bypassing atherosclerotic lesions with venous or arterial grafts. Despite a very low perioperative mortality rate and excellent long-term survival, CABG is associated with postoperative complications, including reperfusion injury, graft failure, atrial fibrillation and perioperative myocardial infarction. So far, no reliable diagnostic and prognostic tools to predict prognosis after CABG have been developed. Changes in the perioperative miRNA expression levels could improve the diagnosis of post-CABG myocardial infarction and atrial fibrillation and could be used to stratify risk after CABG. Herein, we describe the expression changes of different subtypes of miRNAs during CABG and review the diagnostic and prognostic utility of miRNAs in patients undergoing CABG.

An overview of human pericardial space and pericardial fluid

The pericardium is a double-layered fibro-serous sac that envelops the majority of the surface of the heart as well as the great vessels. Pericardial fluid is also contained within the pericardial space. Together, the pericardium and pericardial fluid contribute to a homeostatic environment that facilitates normal cardiac function. Different diseases and procedural interventions may disrupt this homeostatic space causing an imbalance in the composition of immune mediators or by mechanical stress. Inflammatory cells, cytokines, and chemokines are present in the pericardial space. How these specific mediators contribute to different diseases is the subject of debate and research. With the advent of highly specialized assays that can identify and quantify various mediators we can potentially establish specific and sensitive biomarkers that can be used to differentiate pathologies, and aid clinicians in improving clinical outcomes for patients.

Off pump coronary artery bypass in patients with an ejection fraction of <20%. What is our strategy?

Patients with left ventricular dysfunction and low ejection fraction (EF) are at high risk of complication and mortality after coronary artery bypass grafting (CABG). The potential success of off-pump CABG in this high-risk population has yet to be illustrated. Herein, we present our experience in regards to surgical planning and strategy on how to perform off-pump CABG in patients with very low EF.

Patients who develop post-operative atrial fibrillation have reduced survival after off-pump coronary artery bypass grafting

Objective

Post-operative atrial fibrillation (POAF) increases hospital stay, resource utilization, morbidity, and mortality. However, there is paucity of data about its effect in Indian patients undergoing off-pump coronary artery bypass grafting (CABG).

Methods

Seven hundred forty-eight patients underwent off-pump CABG from January 2015 to December 2016 (24 months). One hundred twenty-seven patients (16.7%) developed POAF. In an effort to mitigate the effects of wider risk factors on perioperative outcomes, a separate sub-analysis of patients based on risks quantified by EuroSCORE II (<> 3) was also performed.

Results

Age > 60 years and development of sepsis were the independent predictors for the development of POAF. Thirty-day/mortality rate was higher in the POAF group (7.1% vs. 1.4%; p value < 0.001). POAF was associated with increased ICU and hospital stay and increased incidence of stroke and renal dysfunction. The survival was significantly lower in the POAF group compared with the normal sinus rhythm (NSR) (3-year survival in POAF was 81.3% vs. 94.4% in the NSR group; Hazard ratio (HR) 3.867 (1.989–7.516)). Intra-aortic balloon pump (IABP) usage, age ≥ 60 years and sepsis were independent predictors for the development of POAF in low-risk patients. For the NSR group, 1-year survival was 98% and 3-year survival was 95.7%. For the POAF group, 1-year survival was 94.4% and 3-year survival was 84.0% (HR. 3.794 (1.897–7.591)).

Conclusion

The incidence of POAF was lower than reported in the wider global literature. Increasing age and development of post-operative sepsis were strong independent predictors of POAF. POAF increases the morbidity; length of hospital stay and these patients show decreased survival after off-pump CABG.

The feasibility and safety of off-pump coronary bypass surgery in emergency revascularization

Background

The efficacy and safety of off-pump coronary artery bypass grafting (OPCAB) in emergency revascularization remains controversial despite its widespread use. The aim of our study was to examine the applicability and safety of OPCAB in patients who were indicated for emergency surgery.

Methods

This single-center study reviewed the indication, operative data, and early and long-term outcomes of 113 patients (mean age, 67.2±9.0 years; logistic EuroSCORE, 14.3±13.5) who underwent emergency OPCAB from January 2003 to December 2014 and were followed up (94.6% completion rate) for a mean 51.1±40.3 (range, 1-135) months.

Results

Emergency OPCAB was associated with favorable surgical outcomes (number of distal anastomoses per patient, 3.04±0.87; internal thoracic artery (IMA) use, 98.2%; complete revascularization, 79.6%) and in-hospital outcomes (mortality, 5.3%; low cardiac output syndrome, 5.3%; stroke, 2.7%; pulmonary complications, 8.8%; renal failure, 11.5%). Only five patients (4.4%) required on-pump conversion. The 10-year outcomes were also acceptable (survival, 75.4%±5.6%; major cerebral and cardiovascular events, 52.1%±1.8%). The multivariate risk factors for late mortality were peripheral vascular disease (HR 2.95, 95% CI: 1.11-11.83), cardiogenic shock (HR 3.67, 95% CI: 1.35-9.96), and incomplete revascularization (HR 3.41, 95% CI: 1.06-14.26). When patients were separated by whether the procedure was performed early (<2010) or late (≥2010) in the study period, the late period cohort had better outcomes despite containing higher-risk patients.

Conclusions

Our study suggests that emergency OPCAB can be performed safely and effectively with good hospital outcomes and adequate long-term results. OPCAB strategy can be considered as a good option in emergency revascularization.

Plasma exosomal miR-223 expression regulates inflammatory responses during cardiac surgery with cardiopulmonary bypass

Cardiopulmonary bypass (CPB) induces inflammatory responses, and effective endogenous homeostasis is important for preventing systemic inflammation. We assessed whether plasma exosomal microRNAs in patients undergoing cardiac surgery with CPB are involved in the regulation of inflammatory responses. Plasma samples were isolated from CPB patients (n = 21) at 5 specified time points: pre-surgery, pre-CPB and 2 hours (h), 4 h and 24 h after CPB began. Plasma TNF-α expression was increased after CPB began compared to that in the pre-surgery samples. Plasma IL-8 and IL-6 expression peaked at 4 h after CPB began but was downregulated at 24 h. The number of plasma exosomes collected at 2 h (55.1 ± 8.3%), 4 h (63.8 ± 10.1%) and 24 h (83.5 ± 3.72%) after CPB began was significantly increased compared to that in the pre-CPB samples (42.8 ± 0.11%). These exosomes had a predominantly parental cellular origin from RBCs and platelets. Additionally, the plasma exosomal miR-223 levels were significantly increased after CPB began compared to those in the pre-CPB samples. Further, exosomal miR-223 from plasma collected after CPB began downregulated IL-6 and NLRP3 expression in the monocytes. Here, we present the novel findings that increased plasma exosomal miR-223 expression during cardiac surgery with CPB might play homeostatic roles in downregulating inflammatory responses through intercellular communication.

Five-Year Outcomes after On-Pump and Off-Pump Coronary-Artery Bypass

BACKGROUND

Coronary-artery bypass grafting (CABG) surgery may be performed either with cardiopulmonary bypass (on pump) or without cardiopulmonary bypass (off pump). We report the 5-year clinical outcomes in patients who had been included in the Veterans Affairs trial of on-pump versus off-pump CABG.

METHODS

From February 2002 through June 2007, we randomly assigned 2203 patients at 18 medical centers to undergo either on-pump or off-pump CABG, with 1-year assessments completed by May 2008. The two primary 5-year outcomes were death from any cause and a composite outcome of major adverse cardiovascular events, defined as death from any cause, repeat revascularization (CABG or percutaneous coronary intervention), or nonfatal myocardial infarction. Secondary 5-year outcomes included death from cardiac causes, repeat revascularization, and nonfatal myocardial infarction. Primary outcomes were assessed at a P value of 0.05 or less, and secondary outcomes at a P value of 0.01 or less.

RESULTS

The rate of death at 5 years was 15.2% in the off-pump group versus 11.9% in the on-pump group (relative risk, 1.28; 95% confidence interval [CI], 1.03 to 1.58; P=0.02). The rate of major adverse cardiovascular events at 5 years was 31.0% in the off-pump group versus 27.1% in the on-pump group (relative risk, 1.14; 95% CI, 1.00 to 1.30; P=0.046). For the 5-year secondary outcomes, no significant differences were observed: for nonfatal myocardial infarction, the rate was 12.1% in the off-pump group and 9.6% in the on-pump group (P=0.05); for death from cardiac causes, the rate was 6.3% and 5.3%, respectively (P=0.29); for repeat revascularization, the rate was 13.1% and 11.9%, respectively (P=0.39); and for repeat CABG, the rate was 1.4% and 0.5%, respectively (P=0.02).

CONCLUSIONS

In this randomized trial, off-pump CABG led to lower rates of 5-year survival and event-free survival than on-pump CABG. (Funded by the Department of Veterans Affairs Office of Research and Development Cooperative Studies Program and others; ROOBY-FS ClinicalTrials.gov number, NCT01924442 .).

Clampless versus clamped coronary bypass grafting: does it make a difference?

PURPOSE OF REVIEW

The techniques of coronary artery bypass grafting (CABG) have evolved remarkably over the last two decades since the introduction of off-pump coronary artery bypass (OPCAB). This article focuses on the clinical outcomes of 'clampless' CABG strategies, that include OPCAB with a partial clamp, OPCAB with a proximal suture device, and aorta no-touch OPCAB.

RECENT FINDINGS

Observational studies have shown the superiority of OPCAB for preventing strokes and pulmonary complications. Conversely, recent large-scale randomized controlled trials (RCTs) have been unable to demonstrate the benefits of OPCAB. Because of these differing results across numerous studies, the debate about the overall superiority of OPCAB versus on-pump CABG remains controversial. However, the literature regarding the OPCAB technique with minimized manipulation of the aorta suggests this has likely benefits, especially for high-risk patients.

SUMMARY

Previous large RCTs did not focus on specific approaches of OPCAB or the importance of the experience of surgeons and institutions, and so further studies are needed. Observational studies and meta-analyses have indicated that improved outcomes can be achieved by applying specific OPCAB approaches according to each patient's characteristics.

Off-pump grafting does not reduce postoperative pulmonary dysfunction

Objectives Pulmonary dysfunction is a recognized postoperative complication that may be linked to use of cardiopulmonary bypass. The off-pump technique of coronary artery bypass aims to avoid some of the complications that may be related to cardiopulmonary bypass. In this study, we compared the influence of on-pump or off-pump coronary artery bypass on pulmonary gas exchange following routine surgery. Methods Fifty patients (mean age 60.4 ± 8.4 years) with no preexisting lung disease and good left ventricular function undergoing primary coronary artery bypass grafting were prospectively randomized to undergo surgery with or without cardiopulmonary bypass. Alveolar/arterial oxygen pressure gradients were calculated prior to induction of anesthesia while the patients were breathing room air, and repeated postoperatively during mechanical ventilation and after extubation while inspiring 3 specific fractions of oxygen. Results Baseline preoperative arterial blood gases and alveolar/arterial oxygen pressure gradients were similar in both groups. At both postoperative stages, the partial pressure of arterial oxygen and alveolar/arterial oxygen pressure gradients increased with increasing fraction of inspired oxygen, but there were no statistically significant differences between patients who underwent surgery with or without cardiopulmonary bypass, either during ventilation or after extubation. Conclusions Off-pump surgery is not associated with superior pulmonary gas exchange in the early postoperative period following routine coronary artery bypass grafting in patients with good left ventricular function and no preexisting lung disease.

Surgery for mitral regurgitation in patients with aortic root aneurysm: Transaortic or transseptal approach?

OBJECTIVE

Mitral regurgitation is common in patients with aortic root aneurysm. Mitral valve repair (MVP) or replacement (MVR) can be performed for these patients through either a transverse aortotomy (TA) or transseptal approach (TS). This study sought to compare the early outcomes of mitral valve surgery through the TA and TS approaches and decide which is optimal for this subset of patients.

METHODS

Between March 2013 and April 2015, we operated on 99 patients (81 males, 81.8%) with aortic root aneurysm who developed mitral regurgitation. Mean age was 47.8±16.5years. MVR was performed in 66 patients (TAR=27; TSR=39) and MVP in 33 (TAP=8; TSP=25). The baseline and operative outcomes data were compared between patients with MVR and MVP through the TA vs TS approaches.

RESULTS

Preoperatively, the mitral regurgitation area was significantly larger in the MVR than MVP groups (8.9±2.0 vs 7.8±3.8 cm², p=0.0009), and in the TSP vs TAP groups (8.5±4.1 vs 5.6±1.3cm², p=0.0049), but no significant difference was found between the TAR and TSR groups (8.7±2.2 vs 9.0±1.8cm², p=0.4681); the aortic sinus size was significantly larger in the TAR than TSR group (66.7±15.8 vs 52.1±8.8mm, p=0.0061). Subvalvular structure was preserved in 12 MVR patients (18.2%). In MVP patients, Kay annuloplasty was used in 11 (33.3%) and annuloplastic ring in 22 (66.7%). The times of cardiopulmonary bypass (CPB) and cross-clamp in patients with TA approach were significantly shorter compared to those with the TS approach (139±34 vs 176±38min, p=0.0001; 101±26 vs 129±31min, p=0.0002). No cases of mortality, stroke and renal failure occurred in the whole series. The amount of transfusion, lengths of ICU and hospital stay did not differ between patients with MVR and MVP, and between the TA and TS approaches.

CONCLUSIONS

Both the TA and TS approaches achieved good early outcomes in MV surgery for patients with root aneurysm. The transverse aortotomy was associated with shorter CPB and cross-clamp times. Surgical approaches should be selected according to the underlying mitral valve etiology and the size of the aortic root.

Early outcomes of on-pump versus off-pump coronary artery bypass grafting

Objectives:

To see the early post-operative outcomes of off-pump versus on-pump coronary artery bypass graft surgery.

Methods:

This retrospective analytical study was conducted at Ch. Pervaiz Elahi Institute of Cardiology Multan, Pakistan. Our Primary outcome variables were; necessity of inotropic support, nonfatal myocardial infarction, ICU stay, nonfatal stroke, new renal failure requiring dialysis and death within 30 days after operation. There were two groups of patients; Group-I (On-pump group) and Group-II (Off-pump Group). SPSS V17 was used for data analysis. Independent sample t-test and Mann Whitney U test were used to compare quantitative Variables. Chi-square test and Fisher’s exact test were used to analyze qualitative variables. P-value ≤ 0.05 was considered significant.

Results:

Three hundred patients were included in this study. There were no significant difference regarding risk factors except hyper-cholestrolemia which was high in off pump group (p-value 0.05). Angiographic and Echocardiographic characteristics e.g. preoperative ejection fraction, LV function grade and severity of CAD was same between the groups. Mortality risk scores and Priority status for surgery were also same. Regarding post-operative outcomes; Post-op CKMB Levels, need and duration of inotropic support, mechanical ventilation time and ICU stay was significantly less in Off-Pump group (p-value 0.001, <0.0001, 0.006, 0.025 and 0.001 resp.). Peri-operative chest drainage was significantly high in On-pump CABG group (p-value 0.027). Incidence of post-op complications was not statistically different between the groups.

Conclusions:

At 30 days follow-up, Incidence of myocardial infarction, necessity and duration of inotropic support, ICU stay period and peri-operative bleeding were significantly less in off-pump group. The incidence of neurologic, pulmonary and renal complications was same between the off-pump and on-pump groups.

Pulmonary Complications After Cardiac Surgery

Over the past two decades there has been a steady evolution in the practice of adult cardiac surgery with the introduction of “off-pump” surgery. However, respiratory complications remain a leading cause of postcardiac surgical morbidity and can prolong hospital stays and increase costs. The high incidence of pulmonary complications is in part due to the disruption of normal ventilatory function that is inherent to surgery in the thoracic region. Furthermore, patients undergoing such surgery often have underlying illnesses such as intrinsic lung disease (e.g., chronic obstructive pulmonary disease) and pulmonary dysfunction secondary to cardiac disease (e.g., congestive heart failure) that increase their susceptibility to postoperative respiratory problems. Given that many patients undergoing cardiac surgery are thus susceptiple to pulmonary complications, it is remarkable that more patients do not suffer from them during and after cardiac surgery. This is to a large degree because of advances in anesthetic, surgical and critical care that, for example, have reduced the physiological insults of surgery (e.g., better myocardial preservation techniques) and streamlined care in the immediate postoperative period (e.g., early extubation). Moreover, the development of minimally invasive surgery and nonbypass techniques are further evidence of the attempts at reducing the homeostatic disruptions of cardiac surgery. This review examines the available information on the incidences, consequences, and treatments of postcardiac surgery respiratory complications.

The Impact of Lung Ventilation on Some Cytokines after Coronary Artery Bypass Grafting

Background and Aims:

Cardiopulmonary bypass induces a systematic inflammatory response, which is partly understood by investigation of peripheral blood cytokine levels alone; the lungs may interfere with the net cytokine concentration. We investigated whether lung ventilation influences lung passage of some cytokines after coronary artery bypass grafting.

Material and Methods:

In total, 47 patients undergoing coronary artery bypass grafting were enrolled, and 37 were randomized according to the ventilation technique: (1) No-ventilation group, with intubation tube detached from the ventilator; (2) low tidal volume group, with continuous low tidal volume ventilation; and (3) continuous 10 cm H2O positive airway pressure. Ten selected patients undergoing surgery without cardiopulmonary bypass served as a referral group. Representative pulmonary and radial artery blood samples were collected for the evaluation of calculated lung passage (pulmonary/radial artery) of the pro-inflammatory cytokines (interleukin 6 and interleukin 8) and the anti-inflammatory interleukin 10 immediately after induction of anesthesia (T1), 1 h after restoring ventilation/return of flow in all grafts (T2), and 20 h after restoring ventilation/return of flow in all grafts (T3).

Results:

Pulmonary/radial artery interleukin 6 and pulmonary/radial artery interleukin 8 ratios ( p = 0.001 and p = 0.05, respectively) decreased, while pulmonary/radial artery interleukin 10 ratio ( p = 0.001) increased in patients without cardiopulmonary bypass as compared with patients with cardiopulmonary bypass.

Conclusions:

The pulmonary/radial artery equation is an innovative means for the evaluation of cytokine lung passage after coronary artery bypass grafting. The mode of lung ventilation has no impact on some cytokines after coronary artery bypass grafting in patients treated with cardiopulmonary bypass.

Effects of two differently heparin-coated extracorporeal circuits on markers for brain and myocardial dysfunction

Objective: The two most commonly used heparin-coated systems for cardiopulmonary bypass (CPB) are the Carmeda Bio-Active Surface (CBAS) (Medtronic, Minneapolis, MN, USA) and the Duraflo II coating (Baxter Healthcare, Irvine, CA, USA). The two surfaces are technically unequal and previous experimental studies have demonstrated disparities in effects on the immune system and blood cells. However, little is known concerning the influence of the two surfaces on markers for brain and myocardial dysfunction.

Methods: Forty patients undergoing elective, primary coronary bypass grafting with CPB were prospectively randomized to either the CBAS system or the Duraflo II circuit. During and after CPB, biological markers for brain dysfunction and myocardial injury were analysed.

Results: Both markers for brain dysfunction S-100B and neuron-specific enolase (NSE) increased significantly during CPB ( p =0.01). The elevation during bypass correlated significantly with the duration of CPB ( r = 0.39 and r= 0.38, respectively, both p< 0.02). NSE was somewhat more elevated in the Duraflo II group at the end of CPB ( p =0.01) and 5 h after CPB ( p= 0.02); for S-100B, there were no intergroup differences. Also, the markers related to myocardial injury, myoglobin and creatine kinase (CK-MB) mass increased during CPB ( p= 0.01), while elevation of troponin-I occurred 5 h after CPB ( p= 0.01). There were no statistically significant intergroup differences. No significant correlation was seen between the release of cardiac markers and the duration of CPB. The clinical course was similar in both groups.

Conclusions: Except for a slightly higher elevation of NSE at the end of CPB and 5 h after CPB in the Duraflo II group, there were no significant differences between the CBAS group and the Duraflo II group concerning markers for brain and myocardial dysfunction.

Methylprednisolone prevents inflammatory reaction occurring during cardiopulmonary bypass: effects on TNF-α, IL-6, IL-8, IL-10

Objective: This study examined the correlation between tumour necrosis factor-alfa (TNF-α), interleukin (IL)-6 and IL-8, IL-10 and methylprednisolone pretreatment.

Methods: This is a prospective, randomized and double-blinded study. Sixty patients undergoing coronary artery bypass grafting (CABG) were randomized to receive either intravenous methylprednisolone (n=30, Group M) or intravenous placebo (n=30, Group S). The patients received intravenously either 30 mg/kg methylprednisolone (Group M) or placebo (Group S) 10 min before and after cardiopulmonary bypass (CPB). In an intensive care unit (ICU), four additional doses were given at 6-hourly intervals. Blood samples for the measurements of TNF-α, IL-6, IL-8 and IL-10 were obtained before induction of anaesthesia (T0=control value), after induction (T1), before starting CPB (T2), after aortic declamping (T3), at the end of CPB (T4) and 6 hours (T5), 12 hours (T6) and 24 hours (T7) after skin closure. Creatine kinase (CK) and creatine kinase isoenzyme MB (CK-MB) were evaluated at the following intervals: T0, T5, T6 and T7.

Results: When compared with the control value, TNF-α, IL-6 and IL-8 significantly increased in Group S and Group M (p B-0.05), but these values were significantly greater in Group S than in Group M (p B-0.05). In comparison with the control value, IL-10 increased in both groups (p B-0.05), but was significantly greater in Group M than in Group S (p B-0.05). CK and CK-MB were increased in both groups in postoperative values compared to control values. In Group S, CK and CK-MB levels were significantly lower than in Group M (p B-0.05).

Conclusion: In this study, we have found that pre-operative administration of methylprednisolone has decreased TNF-α, IL-6 and IL-8 release, and increased the perfusing IL-10 levels after CPB. Thus, methylpredniso-lone may decrease the inflammatory response during the CPB procedure.

Demonstration and Operative Influence of Low Prime Volume Closed Pump

Various improvements have been made in cardiopulmonary bypass (CPB) in the past few decades. We designed a new type of CPB to reduce the secretion of systemic inflammatory markers. We used a low prime volume pump (LPVP), completely closed CPB circuit and examined coagulant factors and inflammatory cytokines. In this study, we demonstrate the efficacy of LPVP using molecular biological data. Fourteen patients were randomized prospectively into two groups: Group L patients underwent LPVP ( n = 8) and Group N patients underwent normal prime volume CPB ( n = 6). We measured thrombin-antithrombin III complex (TAT), complement factor (C3a), and interleukin (IL)-10 levels at four time points. TAT (66.1 ± 15.1 ng·mL−1), C3a (1895 ± 282 ng·mL−1) and IL-10 (486 ± 114 pg·mL−1) levels in Group N were significantly higher than in Group L (TAT, 19.5 ± 4.4 ng·mL−1; IL-10, 105 ± 24.6 pg·mL−1; C3a, 1349 ± 369 ng·mL−1) immediately following CPB. LPVP demonstrated a lower systemic inflammatory response compared to normal prime volume CPB, as assessed using a molecular biological approach.

Off-Pump Coronary Artery Bypass Surgery

Off-pump coronary artery bypass surgery has been adopted enthusiastically worldwide. However, despite more than 6 years’ experience and refinement, many surgeons use it only sporadically and some hardly at all. This reluctance persists despite support for the procedure because of the lack of properly designed risk models and/or randomized studies. Although it has not been overwhelmingly shown that off-pump surgery is superior to the conventional on-pump procedure, the technique has its place in our specialty. It has been shown to be better for noncritical end points in selected patients in the hands of selected surgeons. That there are differences in surgical skill among surgeons is something we all know but rarely discuss in public. Until now, disparities in skill have been most salient with uncommon and extraordinarily challenging operations. Perhaps the off-pump procedure should be regarded as the “challenging” aspect of coronary artery bypass surgery, and self-restraint may need to remain in force if we are to continue to achieve the highest level of clinical excellence.

Equivalence of the Acute Cytokine Surge and Myocardial Injury after Coronary Artery Bypass Grafting with and without a Novel Extracorporeal Circulation System

Cardiopulmonary bypass (CPB) contributes to a morbidity-inducing systemic Inflammatory response after cardiac surgery. We compared this response in patients receiving coronary artery bypass grafting (CABG) with (CPB group; n = 7) or without (off-pump group; n = 8) the Minimal Extracorporeal Circulation (MECC®) system. Serum concentrations of tumour necrosis factor (TNF)-α, soluble TNF receptors, pro- and anti-inflammatory interleukins (ILs) and other myocardial injury markers were measured after anaesthetic induction, at 1 h, 4 h and 24 h after completing all anastomoses or serially. Soluble TNF receptor type I (sTNFRI) and IL-8 peaked early after CABG in both groups and did not decline. Serum sTNFRI was significantly higher in the CPB compared with the off-pump group at 1 h, whereas IL-8 was significantly lower in the CPB group throughout. The MECC® system, therefore, produces an equivalent acute cytokine response and degree of myocardial injury to off-pump CABG, and may be useful when CABG cannot be performed without CPB.

Pharmacological strategies for prevention of postoperative atrial fibrillation

Atrial fibrillation (AF) complicating cardiac surgery continues to be a major problem that increases the postoperative risk of stroke, myocardial infarction, heart failure and costs and can affect long-term survival. The incidence of AF after surgery has not significantly changed over the last two decades, despite improvement in medical and surgical techniques. The mechanism and pathophysiology underlying postoperative AF (PoAF) is incompletely understood and results from a combination of acute and chronic factors, superimposed on an underlying abnormal atrial substrate with increased interstitial fibrosis. Several anti-arrhythmic and non-anti-arrhythmic medications have been used for the prevention of PoAF, but the effectiveness of these strategies has been limited due to a poor understanding of the basis for the increased susceptibility of the atria to AF in the postoperative setting. In this review, we summarize the pathophysiology underlying the development of PoAF and evidence behind pharmacological approaches used for its prevention in the postoperative setting.

Pulmonary complications of cardiopulmonary bypass

Pulmonary complications after the use of extracorporeal circulation are common, and they range from transient hypoxemia with altered gas exchange to acute respiratory distress syndrome (ARDS), with variable severity. Similar to other end-organ dysfunction after cardiac surgery with extracorporeal circulation, pulmonary complications are attributed to the inflammatory response, ischemia-reperfusion injury, and reactive oxygen species liberated as a result of cardiopulmonary bypass. Several factors common in cardiac surgery with extracorporeal circulation may worsen the risk of pulmonary complications including atelectasis, transfusion requirement, older age, heart failure, emergency surgery, and prolonged duration of bypass. There is no magic bullet to prevent or treat pulmonary complications, but supportive care with protective ventilation is important. Targets for the prevention of pulmonary complications include mechanical, surgical, and anesthetic interventions that aim to reduce the contact activation, systemic inflammatory response, leukocyte sequestration, and hemodilution associated with extracorporeal circulation.

Evaluation of systemic inflammatory response in cardiovascular surgery via interleukin-6, interleukin-8, and neopterin

AIM

The aim of this study was to evaluate the serum levels of interleukin-6 (IL-6), IL-8, and neopterin as a sign of systemic inflammatory response syndrome after open-heart surgery. In this study, we evaluated the influences on the levels of IL-6, IL-8, and neopterin of coronary artery bypass grafting (CABG) and valve replacement surgeries with and without the use of extracorporeal circulation (ECC).

MATERIALS AND METHODS

This prospective study was performed in 30 patients. In this study, we evaluated patients who underwent valve replacement surgery (group 1, n = 10), CABG with ECC (group 2, n = 10), or CABG using the beating-heart technique (group 3, n = 10). With the Human Investigation Ethics Committee consent, blood samples were obtained from the patients before the surgery (T0) and after 1 hour (T1), 4 hours (T2), 24 hours (T3), and 48 hours (T4) of protamine injection. IL-6, IL-8, and neopterin levels were measured using commercial enzyme-linked immunosorbent assay kits.

RESULTS

The demographic data and preoperative and operative characteristics of the patients were similar. Neopterin IL-6 and IL-8 levels significantly increased first at the fourth hour after the surgery. When compared to the levels before the surgery, this increase was statistically significant. Unlike the other 2 groups of patients, those who experienced CABG with the beating-heart technique (group 3) had decreased neopterin levels at the first hour after the surgery, but this decrease was not statistically significant. Neopterin levels increased later in the OPCAB group, but these increased levels were not as high as the neopterin levels of groups 1 and 2. Neopterin reached maximum levels at the 24th hour and, unlike groups 1 and 2, in group started to decrease at the 48th.

CONCLUSIONS

Complement activation, cytokine production, and related cellular responses are important factors during open-heart surgery. It is certain that ECC activates the complement systems, and activated complement proteins cause the production of several cytokines. In our study, neopterin levels in patients who underwent beating-heart method surgery were lower than those in the other groups, and these levels started to decrease at the 48th hour. These data suggest that the systemic inflammatory response was less activated in that patient group. The beating-heart method might be an important alternative in CABG surgery to minimize the complications and mortality related to surgery.

Lung inflammatory response syndrome after cardiac-operations and treatment of lornoxicam

The majority of patients survive after extracorporeal circulation without any clinically apparent deleterious effects. However, disturbances exist in various degrees sometimes, which indicate the harmful effects of cardiopulmonary bypass (CPB) in the body. Several factors during extracorporeal circulation either mechanical dependent (exposure of blood to non-biological area) or mechanical independent (surgical wounds, ischemia and reperfusion, alteration in body temperature, release of endotoxins) have been shown to trigger the inflammatory reaction of the body. The complement activation, the release of cytokines, the leukocyte activation and accumulation as well as the production of several "mediators" such as oxygen free radicals, metabolites of arachidonic acid, platelet activating factors (PAF), nitric acid, and endothelin. The investigation continues today on the three metabolites of lornoxicam (the hydroxylated metabolite and two other metabolites of unknown chemical composition) to search for potential new pharmacological properties and activities.

Ventilation during cardiopulmonary bypass did not attenuate inflammatory response or affect postoperative outcomes

Introduction

Cardiopulmonary bypass causes a series of inflammatory events that have adverse effects on the outcome. The release of cytokines, including interleukins, plays a key role in the pathophysiology of the process. Simultaneously, cessation of ventilation and pulmonary blood flow contribute to ischaemia–reperfusion injury in the lungs when reperfusion is maintained. Collapse of the lungs during cardiopulmonary bypass leads to postoperative atelectasis, which correlates with the amount of intrapulmonary shunt. Atelectasis also causes post-perfusion lung injury. In this study, we aimed to document the effects of continued low-frequency ventilation on the inflammatory response following cardiopulmonary bypass and on outcomes, particularly pulmonary function.

Methods

Fifty-nine patients subjected to elective coronary bypass surgery were prospectively randomised to two groups, continuous ventilation (5 ml/kg tidal volume, 5/min frequency, zero end-expiratory pressure) and no ventilation, during cardiopulmonary bypass. Serum interleukins 6, 8 and 10 (as inflammatory markers), and serum lactate (as a marker for pulmonary injury) levels were studied, and alveolar–arterial oxygen gradient measurements were made after the induction of anaesthesia, and immediately, one and six hours after the discontinuation of cardiopulmonary bypass.

Results

There were 29 patients in the non-ventilated and 30 in the continuously ventilated groups. The pre-operative demographics and intra-operative characteristics of the patients were comparable. The serum levels of interleukin 6 (IL-6) increased with time, and levels were higher in the non-ventilated group only immediately after discontinuation of cardiopulmonary bypass. IL-8 levels significantly increased only in the non-ventilated group, but the levels did not differ between the groups. Serum levels of IL-10 and lactate also increased with time, and levels of both were higher in the non-ventilated group only immediately after the discontinuation of cardiopulmonary bypass. Alveolar–arterial oxygen gradient measurements were higher in the non-ventilated group, except for six hours after the discontinuation of cardiopulmonary bypass. The intubation time, length of stay in intensive care unit and hospital, postoperative adverse events and mortality rates were not different between the groups.

Conclusion

Despite higher cytokine and lactate levels and alveolar–arterial oxygen gradients in specific time periods, an attenuation in the inflammatory response following cardiopulmonary bypass due to low-frequency, low-tidal volume ventilation could not be documented. Clinical parameters concerning pulmonary and other major system functions and occurrence of postoperative adverse events were not affected by continuous ventilation.

Effect of 6% hydroxyethyl starch 130/0.4 as a priming solution on coagulation and inflammation following complex heart surgery

PURPOSE

Prolonged duration of cardiopulmonary bypass aggravates the degree of inflammation and coagulopathy. We investigated the influence of 6% hydroxyethyl starch (HES) 130/0.4 on coagulation and inflammation compared with albumin when used for both cardiopulmonary bypass priming and perioperative fluid therapy in patients undergoing complex valvular heart surgery.

MATERIALS AND METHODS

Fifty four patients were randomly allocated into albumin-HES, albumin-nonHES, and HES-HES groups. The cardiopulmonary bypass circuit was primed with 5% albumin in the albumin-HES and albumin-nonHES group, and with HES in the HES-HES group. As perioperative fluid, only plasmalyte was used in the albumin-nonHES group whereas HES was used up to 20 mL/kg in the albumin-HES and albumin-HES group. Serial assessments of coagulation profiles using the rotational thromboelastometry and inflammatory markers (tissue necrosis factor-α, interleukin-6, and interleukin-8) were performed.

RESULTS

Patients' characteristics and the duration of cardiopulmonary bypass (albumin-HES; 137±34 min, HES-HES; 136±47 min, albumin-nonHES; 132±39 min) were all similar among the groups. Postoperative coagulation profiles demonstrated sporadic increases in clot formation time and coagulation time, without any differences in the actual amount of perioperative bleeding and transfusion requirements among the groups. Also, inflammatory markers showed significant activation after cardiopulmonary bypass without any differences among the groups.

CONCLUSION

Even in the presence of prolonged duration of cardiopulmonary bypass, HES seemed to yield similar influence on the ensuing coagulopathy and inflammatory response when used for priming and perioperative fluid therapy following complex valvular heart surgery compared with conventional fluid regimen including albumin and plasmalyte.

Effect of lornoxicam in lung inflammatory response syndrome after operations for cardiac surgery with cardiopulmonary bypass

BACKGROUND

The establishment of Extracorporeal Circulation (EC) significantly contributed to improvement of cardiac surgery, but this is accompanied by harmful side-effects. The most important of them is systemic inflammatory response syndrome. Many efforts have been undertaken to minimize this problem but unfortunately without satisfied solution to date.

MATERIALS AND METHODS

Lornoxicam is a non steroid anti-inflammatory drug which temporally inhibits the cycloxygenase. In this clinical trial we study the effect of lornoxicam in lung inflammatory response after operations for cardiac surgery with cardiopulmonary bypass. In our study we conclude 14 volunteers patients with ischemic coronary disease undergoing coronary artery bypass grafting with EC. In seven of them 16 mg lornoxicam was administered iv before the anesthesia induction and before the connection in heart-lung machine. In control group (7 patients) we administered the same amount of normal saline.

RESULTS

Both groups are equal regarding pro-operative and intra-operative parameters. The inflammatory markers were calculated by Elisa method. We measured the levels of cytokines (IL-6, IL-8, TNF-a), adhesion molecules (ICAM-1, e-Selectin, p-Selectin) and matrix metaloproteinase-3 (MMP-3) just after anesthesia induction, before and after cardiopulmonary bypass, just after the patients administration in ICU and after 8 and 24 hrs. In all patients we estimated the lung's inflammatory reaction with lung biopsy taken at the begging and at the end of the operation. We calculated hemodynamics parameters: Cardiac Index (CI), Systemic Vascular Resistance Index (SVRI), Pulmonary Vascular Resistance Index (PVRI), Left Ventricular Stroke Work Index (LVSWI), Right Ventricular Stroke Work Index (RVSWI), and the Pulmonary arterial pressure, and respiratory parameters too: alveolo-arterial oxygen difference D (A-a), intrapulmonary shunt (Qs/Qt) and pulmonary Compliance. IL-6 levels of lornoxicam group were statistical significant lower at 1st postoperative day compared to them of control group (113±49 and 177±20 respectively, P=0.008). ICAM-1 levels were statistical significant lower at the patient admission in ICU, compared to them of control group (177±29 and 217±22 respectively, P=0.014), and the 1st postoperative day compared to them in control group (281±134 and 489±206 respectively, P=0.045). P-selectin levels were statistical significant lower, compared to them in control group in four measurements (97±23 and 119±7 respectively, P=0.030, 77±19 and 101±20 respectively, P=0.044, 86±4 and 105±13 respectively, P=0.06, 116±13 and 158±17 respectively, P=0.000).

CONCLUSIONS

Hemodynamics and respiratory parameters were improved compared to control group, but these differences was not statistical significant. Eosinofil adhesion and sequestration in intermediate tissue of lung parenchyma were significantly lower compared to control group. Also, alveolar edema was not noted in lornoxicam's group. Lornoxicam reduce the inflammatory response in patients undergone coronary artery bypass grafting with extracorporeal circulation. This calculated from levels reduction of IL-6, ICAM-1 και p-Selectin, and from lung pathologoanatomic examination (absence of alveolar edema, reduce in eosinofil adhesion and sequestration in intermediate tissues). Despite the favorable effect of lornoxicam on the hemodinamics and respiratory parameters these improvement did not seem to be statistical significant.

Optimal coronary artery bypass grafting strategy for acute coronary syndrome

OBJECTIVE

Conventional coronary artery bypass grafting (CABG) using cardiopulmonary bypass and cardiac arrest is associated with higher mortality and morbidity rates in acute coronary syndrome (ACS) patients undergoing surgery. Although off-pump CABG (OPCAB) is beneficial for high-risk patients, its efficacy for ACS is unknown, with on-pump beating CABG an adjunctive method. We investigated the effects of OPCAB and on-pump beating CABG for ACS.

METHODS

We evaluated 121 consecutive patients with ACS (91 males, 30 females; mean age 69.5 ± 10.3 years) who underwent CABG since 2000. Seventy-five had unstable angina (UA) and 46 acute myocardial infarction (AMI) [non-ST elevation (NSTEMI): 22, ST elevation (STEMI): 24]. We assessed CABG for acute coronary syndrome under our primary OPCAB strategy, and compared perioperative status between UA and AMI patients.

RESULTS

(1) Sixty-five (87 %) with UA underwent OPCAB, 8 on-pump beating CABG, and 2 conventional CABG. Conversion from OPCAB was seen in 4 patients. In-hospital mortality was 1.3 %. (2) All UA patients who had intra-aortic balloon pumping (IABP) underwent OPCAB. No patients with preoperative IABP experienced conversion from OPCAB. (3) In AMI patients, hospital mortality was higher (8.9 %) and the ratios for OPCAB, on-pump beating CABG, and conventional CABG were 39, 57, and 4 %, respectively. Mortality was exclusively seen in patients with STEMI who underwent conventional CABG.

CONCLUSIONS

OPCAB might have beneficial effects for ACS patients with UA, while IABP was found essential for completing OPCAB. In AMI patients, on-pump beating CABG might be reasonable for avoiding conversion from OPCAB and ischemic perfusion injury.

Video-assisted thoracic surgery in lung cancer resection: a meta-analysis and systematic review of controlled trials

OBJECTIVES

: This meta-analysis sought to determine whether video-assisted thoracic surgery (VATS) improves clinical and resource outcomes compared with thoracotomy (OPEN) in adults undergoing lobectomy for nonsmall cell lung cancer.

METHODS

: A comprehensive search was undertaken to identify all randomized (RCT) and nonrandomized (non-RCT) controlled trials comparing VATS with OPEN thoracotomy available up to April 2007. The primary outcome was survival. Secondary outcomes included any other reported clinical outcome and resource utilization. Odds ratios (OR), weighted mean differences (WMD), or standardized mean differences (SMD), and their 95% confidence intervals (95% CI) were analyzed as appropriate.

RESULTS

: Baseline prognosis was more favorable for VATS (more females, smaller tumor size, less advanced stage, histology associated with peripheral location and with more indolent disease) than for OPEN in non-RCTs, but not RCT. Postoperative complications were significantly reduced in the VATS group compared with OPEN surgery when both RCT and non-RCT were considered in aggregate (OR 0.48, 95% CI 0.32-0.70). Although overall blood loss was significantly reduced with VATS compared with OPEN (-80 mL, 95% CI -110 to -50 mL), the incidence of excessive blood loss (generally defined as >500 mL) and incidence of re-exploration for bleeding was not significantly reduced. Pain measured via visual analog scales (10-point VAS) was significantly reduced by <1 point on day 1, by >2 points at 1 week, and by <1 point at week 2 to 4. Similarly, analgesia requirements were significantly reduced in the VATS group. Postoperative vital capacity was significantly improved (WMD 20, 95% CI 15-25), and at 1 year was significantly greater for VATS versus OPEN surgery (WMD 7, 95% CI 2-12). The incidence of patients reporting limited activity at 3 months was reduced (OR 0.04, 95% CI 0.00-0.82), and time to full activity was significantly reduced in the VATS versus OPEN surgery (WMD -1.5, 95% CI -2.1 to -0.9). Overall patient-reported physical function scores did not differ between groups at 3 years follow-up. Hospital length of stay was significantly reduced by 2.6 days despite increased 16 minutes of operating time for VATS versus OPEN. The incidence of cancer recurrence (local or distal) was not significantly different, but chemotherapy delays were significantly reduced for VATS versus OPEN (OR 0.15, 95% CI 0.06-0.38). The need for chemotherapy reduction was also decreased (OR 0.37, 95% CI 0.16-0.87), and the number of patients who did not receive at least 75% of their planned chemotherapy without delays were reduced (OR 0.41, 95% CI 0.18-0.93). The risk of death was not significantly reduced when RCTs were considered alone; however, when non-RCTs (n = 18) were included, the risk of death at 1 to 5 years was significantly reduced (OR 0.72, 95% CI 0.55-0.94; P = 0.02) for VATS versus OPEN. Stage-specific survival to 5 years was not significantly different between groups.

CONCLUSIONS

: This meta-analysis suggests that there may be some short term, and possibly even long-term, advantages to performing lung resections with VATS techniques rather than through conventional thoracotomy. Overall, VATS for lobectomy may reduce acute and chronic pain, perioperative morbidity, and improve delivery of adjuvant therapies, without a decrease in stage specific long-term survival. However, the results are largely dependent on non-RCTs, and future adequately powered randomized trials with long-term follow-up are encouraged.

Off-pump versus on-pump coronary artery bypass grafting in octogenarians: comparison of short-term outcomes and long-term survival

Off-pump coronary artery bypass (OPCAB) has gained increasing acceptance with potential benefits for high-risk elderly patients. We report a surgeon's operative outcomes in octogenarians with an OPCAB program. Retrospective, intention-to-treat analysis of 97 consecutive octogenarians who underwent coronary bypass by a single surgeon between 1997 and 2001 before and after initiation of a multi-vessel OPCAB program was performed. OPCAB was attempted in all octogenarians. The OPCAB cohort had higher serum creatinine (OPCAB vs. pre-OPCAB: 1.30 ± 0.79 mg/dl vs. 1.08 ± 0.27, p = 0.04) and ejection fractions (52 ± 14% vs. 45 ± 11%, p = 0.02) than the pre-OPCAB cohort. The OPCAB group was more likely to require urgent/emergency surgery (63 vs. 40%, p = 0.04) and to have chronic renal insufficiency (18 vs. 3%, p = 0.05). After programmatic change to OPCAB, significant postoperative improvements were observed in the length of hospital stay (17 ± 19 vs. 8 ± 4 days, p < 0.01), duration of inotropic requirement (47 ± 70 vs. 18 ± 39 h, p < 0.04), duration of ventilator support (51 ± 54 vs. 16 ± 27 h, p < 0.01) and incidence of tracheostomy (16 vs. 3%, p < 0.02). In-hospital mortalities (3.2 vs. 2.7%), strokes (3 per group) and 5-year survival did not differ significantly (57 vs. 67%, p = 0.50, NS). Despite some higher preoperative risks, the OPCAB program demonstrated clinical benefits in octogenarians but no advantage in hospital-mortality or long-term survival.

Clinical outcome and quality of life after reoperative CABG: off-pump versus on-pump - observational pilot study

Background

Coronary artery bypass grafting (CABG) on cardiopulmonary bypass (CBP) is associated with significant morbidity and mortality. In high-risk patients, doomed for reoperation the adverse effects of CBP may be more striking. We evaluated the results of reoperative CABG (redo-CABG) by either off-pump (OPCAB) or on-pump (ONCAB). Clinical endpoints were perioperative myocardial infarction, mortality, survival and as the most striking difference between prior studies the quality of life (QoL).

Methods

We performed a prospective, non-randomized assessment for patients who underwent redo-CABG by redo-OPCAB (n = 40) or redo-ONCAB (n = 40) at our institution between January 2007 and December 2010. For evaluation of QoL the SF-36 health survey was used with self-administered assessment.

Results

During follow-up 37 of 40 patients were alive in the redo-OPCAB group versus 32 of 40 patients in the redo-ONCAB group (p < 0.05). The shorter operation time, less blood loss, fewer perioperative myocardial infarctions, the higher rate of totally arterial revascularisation and shorter intensive care stay were the significantly beneficial differences for patients in the redo-OPCAB group (p < 0.05). The 3-year survival rate was higher in the redo-OPCAB group with 81 ± 12% versus 63 ± 9%in the redo-ONCAB group. The quality of life survey did not reveal any significant differences between both groups.

Conclusion

In conclusion, with our present retrospective study, we could demonstrate the safety and efficacy of the redo-OPCAB technique with even higher 3-year survival rate. Both techniques seem to have similar impact on the outcome of patients.

The early inflammatory response in a mini-cardiopulmonary bypass system: a prospective randomized study

OBJECTIVE

The aim of this study was to compare the early systemic inflammatory response of the Resting Heart System (RHS; Medtronic, Minneapolis, MN USA), a miniaturized cardiopulmonary bypass (CPB) system, with two groups using a standard extracorporeal circulation system during on-pump coronary artery bypass grafting (CABG) surgery.

METHODS

A total of 60 consecutive patients requiring CABG were prospectively randomized to undergo on-pump CABG using conventional CPB without cardiotomy suction (group A), conventional CPB with cardiotomy suction (group B), or the RHS (group C). Blood samples were collected at five time points: immediately before CPB, 30 minutes into CPB, immediately at the end of CPB, 30 minutes post-CPB, and 1 hour post-CPB. Inflammation was analyzed by changes in (a) levels of plasma proteins, including inflammatory cytokines (interleukin-6 [IL-6], IL-10, and tumor necrosis factor-α), chemokines (IL-8, monokine induced by interferon-γ, monocyte chemotactic protein-1, regulated on activation normal T cell expressed and secreted, and interferon-inducible protein-10), and acute phase proteins (C-reactive protein and complement protein 3); (b) biochemical variables (cardiac troponin I, hematocrit, and immunoglobulin G); and (c) cell numbers (leukocytes, neutrophils, and thrombocytes).

RESULTS

The RHS showed more delayed secretion of the cytokines tumor necrosis factor-α and IL-10, chemokines monokine induced by interferon-γ (P < 0.001); IL-8, and interferon-inducible protein-10; and complement protein 3 than conventional CPB systems did. Median thrombocyte numbers were higher in the RHS group. Levels of cardiac troponin I, monocyte chemotactic protein-1, and IL-6 were lower in both the RHS and conventional CPB without suction than with suction. Levels of C-reactive protein and regulated on activation normal T cell expressed and secreted, plus leukocyte and neutrophil numbers, were similar in all groups.

CONCLUSIONS

The Medtronic RHS may induce less systemic inflammation than conventional CPB systems, particularly when cardiotomy suction was used, but it did not result in improved clinical benefit.

Pulmonary pathophysiology and lung mechanics in anesthesiology: a case-based overview

Anesthesia, surgical requirements, and patients' unique pathophysiology all combine to make the accumulated knowledge of respiratory physiology and lung mechanics vital in patient management. This article take a case-based approach to discuss how the complex interactions between anesthesia, surgery, and patient disease affect patient care with respect to pulmonary pathophysiology and clinical decision making. Two disparate scenarios are examined: a patient with chronic obstructive pulmonary disease undergoing a lung resection, and a patient with coronary artery disease undergoing cardiopulmonary bypass. The impacts of important concepts in pulmonary physiology and respiratory mechanics on clinical management decisions are discussed.

Post-operative atrial fibrillation: a maze of mechanisms

Post-operative atrial fibrillation (POAF) is one of the most frequent complications of cardiac surgery and an important predictor of patient morbidity as well as of prolonged hospitalization. It significantly increases costs for hospitalization. Insights into the pathophysiological factors causing POAF have been provided by both experimental and clinical investigations and show that POAF is ‘multi-factorial’. Facilitating factors in the mechanism of the arrhythmia can be classified as acute factors caused by the surgical intervention and chronic factors related to structural heart disease and ageing of the heart. Furthermore, some proarrhythmic mechanisms specifically occur in the setting of POAF. For example, inflammation and beta-adrenergic activation have been shown to play a prominent role in POAF, while these mechanisms are less important in non-surgical AF. More recently, it has been shown that atrial fibrosis and the presence of an electrophysiological substrate capable of maintaining AF also promote the arrhythmia, indicating that POAF has some proarrhythmic mechanisms in common with other forms of AF. The clinical setting of POAF offers numerous opportunities to study its mechanisms. During cardiac surgery, biopsies can be taken and detailed electrophysiological measurements can be performed. Furthermore, the specific time course of POAF, with the delayed onset and the transient character of the arrhythmia, also provides important insight into its mechanisms.

This review discusses the mechanistic interaction between predisposing factors and the electrophysiological mechanisms resulting in POAF and their therapeutic implications.

On-pump coronary surgery with and without cardioplegic arrest: comparison of inflammation, myocardial, cerebral and renal injury and early and late health outcome in a single-centre randomised controlled trial

OBJECTIVE

To assess the safety and efficacy of on-pump beating heart coronary surgery on organ function, and early and late health outcome as compared with conventional technique.

METHODS

A total of 81 patients were randomised to (1) coronary surgery with cardiopulmonary bypass (CPB) and cardioplegic arrest (CA) (on-pump with CA, n=41) or to (2) CPB without CA (on-pump without CA, n=40). Primary outcomes included serial measurement of interleukins (IL-6, IL-8 and IL-10) for inflammation, troponin I for myocardial injury, protein S100 for cerebral injury and creatinine clearance (CrCl) and urinary N-acetyl-β-d-glucosaminidase (NAG) for renal injury. In-hospital health outcome and 5-year event-free survival were secondary outcomes.

RESULTS

Baseline and intra-operative characteristics were similar between groups. A marked release of ILs was observed in both groups, but no significant differences between the groups were found (IL-6 +9%, 95% confidence interval (CI) -15% to +39%, p=0.49; IL-8 +4%, 95% CI -34% to +63%, p=0.86; IL-10 -0.1%, 95% CI -19% to +21%, p=0.93). Troponin I rose in both groups and was on average 34% higher in the on-pump without CA group but this did not reach statistical significance (95% CI -0.4% to +87%, p=0.08). S100 protein was higher in the on-pump without CA group at 12h (p=0.04) but did not differ at other times (p=0.16). The level of CrCl was higher 1h in the on-pump without CA group (+23%, 95% CI +1% to +50%, p=0.04), but not thereafter. NAG release was similar in both groups (+1% 95% CI -23% to +33%, p=0.91). Early and 5-year health outcomes were similar.

CONCLUSIONS

On-pump without CA coronary surgery does not provide any obvious advantage when compared with the conventional technique of on-pump with CA in elective patients. Both techniques provide a comparable degree of inflammatory activation, myocardial, cerebral and renal injury with similar 5-year event-free survival.

A Transapical or Transluminal Approach to Aortic Valve Implantation Does Not Attenuate the Inflammatory Response

Background: Cardiopulmonary bypass (CPB) and cardiac surgery cause an inflammatory response, as measurable by an increase in the concentration of C-reactive protein (CRP), a nonspecific inflammation marker. Previous publications have demonstrated typical perioperative CRP concentration profiles in cases of uncomplicated aortic valve replacement (AVR) with CPB. A regression analysis for modifying factors showed that chronic disease (heart failure, diabetes, and pulmonary disease), along with obesity and sex, all tend to influence the CRP response. We analyzed the inflammatory response to aortic valve implantation (AVI) with interventional techniques, mainly transapical but also transfemoral and transaxillary approaches, in a retrospective case-control study design.Methods: Sixty-eight patients who underwent AVI by the transapical (59 patients), transfemoral (7 patients), or transaxillary (2 patients) approach were matched by age, sex, body mass index (BMI), and chronic-disease state (absence or presence of diabetes, pulmonary disease, and renal impairment) with 68 patients who underwent conventional AVR with CPB. We compared the 2 groups with respect to perioperative CRP concentration, EuroSCORE, and outcome data (time to extubation and 30-day mortality). All data were collected prospectively and analyzed retrospectively.Results: The 2 groupsthe study population (interventional) and the control population (conventional)were similar in age, sex distribution, BMI, and chronic-disease status. As expected, the study population had a significantly higher median EuroSCORE. The 2 groups had similar postoperative CRP profiles over time, but the interventional group had significantly higher peak concentrations on days 2, 3, and 4. The short-term outcomes, as assessed by ventilation time and 30-day mortality, were similar for the 2 groups.Conclusions: Using an interventional transcatheter approach to AVI (thereby eliminating CPB from the procedure and reducing surgical trauma) does not attenuate the patient's innate inflammatory response.

Beating-heart coronary artery bypass surgery with the help of mini extracorporeal circulation for very high-risk patients

Background: Left ventricle dysfunction and co-morbidities are responsible for a large number of complications after coronary artery bypass graft (CABG) surgery. The best strategy for these patients, including the use or not and type of extracorporeal circulation (ECC), the use of minimized ECC (MECC), or conventional ECC (CECC), remains unclear. The aim of the present study was to investigate the potential effect of on-pump beating-heart (OPBH) surgery with the help of MECC for CABG in patients with a high-risk EuroSCORE and to compare this strategy to three other different procedures, including OPCAB and MECC or CECC with cardiac arrest.

Methods: Patients were included if their EuroSCORE was strictly >" xbd="1427" xhg="1404" ybd="1477" yhg="1440"/>9. Four groups were retrospectively compared: an OPCAB, an OPBH, a MECC and a CECC group under cardiac arrest.

Results: 214 patients, mean age 74.26 ± 8.5 years, 68.7% male, were operated. Mean EuroSCORE was 12.1 ± 2.9, left ventricular (LV) function 37.4 ± 12.3%, recent myocardial infarction (MI) 49.5%, renal failure 48.1%, chronic obstructive pulmonary disease (COPD) 42.2%, and peripheral vascular disease (PVD) 55.6%. Mean number of grafts per patient was 2.4 ± 0.7. Our study showed that it was possible, in very high-risk patients, to carry out revascularisation with OPBH similar to that using MECC or CECC under cardiac arrest (p=NS). This technique reduces troponin release (3.23 vs 6.56, p<0.01), postoperative myocardial complications (2% vs 8%, p<0.01), cardiotonic drug prescription (15.7% vs 31.3%, p<0.01), ventilation time (4.57H vs 6.48H, p<0.01) and length of stay (LOS) in ICU (2.16 vs 2.53, p=0.02).

Conclusion: The OPBH method seems to be safe, secure and effective in this population of very high-risk patients, reducing early complications and multi-organ failure. OPBH surgery, combining MECC without aortic cross-clamping, makes it possible to perform complete revascularization and is an interesting alternative for CABG in high-risk patients.