The influence of cardiopulmonary bypass on cytokines and cell-cell communication

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.

Perioperative Ketamine and Cancer Recurrence: A Comprehensive Review

Cancer is a significant global health threat and a leading cause of death worldwide. Effective early-stage interventions, particularly surgery, can potentially cure many solid tumors. However, the risk of postoperative cancer recurrence remains high. Recent research highlights the influence of perioperative anesthetic and analgesic choices on the fate of residual cancer cells, potentially affecting recurrence risks. Among these agents, ketamine-a well-known anesthetic and analgesic-has garnered interest due to its antitumor properties, mainly through inhibiting the N-methyl-D-aspartate (NMDA) receptor found in various cancer tissues. Additionally, ketamine's potential immunomodulatory effects, given the expression of NMDA receptors on immune cells, suggest that it plays a significant role during the perioperative period. This review synthesizes current evidence on ketamine's impact on cancer cell biology, inflammation, immune modulation, and the role of the gut microbiota, proposing ketamine as a promising agent for enhancing oncological outcomes.

Prolonged Systemic Inflammatory Response Syndrome After Cardiac Surgery

OBJECTIVES

Cardiac surgery induces systemic inflammatory response syndrome (SIRS), leading to higher morbidity and mortality. There are no individualized predictors for worse outcomes or biomarkers for the multifactorial, excessive inflammatory response. The interest of this study was to evaluate whether a systematic use of the SIRS criteria could be used to predict postoperative outcomes beyond infection and sepsis, and if the development of an exaggerated inflammation response could be observed preoperatively.

DESIGN

The study was observational, with prospectively enrolled patients.

SETTING

This was a single institution study in a hospital setting combined with laboratory findings.

PARTICIPANTS

The study included a cohort of 261 volunteer patients.

INTERVENTIONS

Patients underwent cardiac surgery with cardiopulmonary bypass, and were followed up to 90 days. Biomarker profiling was run preoperatively.

MEASUREMENTS AND MAIN RESULTS

Altogether, 17 of 261 (6.4%) patients had prolonged SIRS, defined as fulfilling at least 2 criteria on 4 consecutive postoperative days. During hospitalization, postoperative atrial fibrillation (POAF) was found in 42.2% of patients, and stroke and transient ischemic attack in 3.8% of patients. Prolonged SIRS was a significant predictor of POAF (odds ratio [OR] 4.5, 95% CI 1.2-17.3), 90-day stroke (OR 4.5, 95% CI 1.1-18.0), and mortality (OR 10.7, 95% CI 1.7-68.8). Biomarker assays showed that preoperative nerve growth factor and interleukin 5 levels were associated with prolonged SIRS (OR 5.6, 95%, CI 1.4-23.2 and OR 0.7, 95%, CI 0.4-1.0, respectively).

CONCLUSIONS

Nerve growth factor and interleukin 5 can be used to predict prolonged systemic inflammatory response, which is associated with POAF, stroke, and mortality.

Biochemical Changes in Cardiopulmonary Bypass in Cardiac Surgery: New Insights

Patients undergoing coronary revascularization with extracorporeal circulation or cardiopulmonary bypass (CPB) may develop several biochemical changes in the microcirculation that lead to a systemic inflammatory response. Surgical incision, post-CPB reperfusion injury and blood contact with non-endothelial membranes can activate inflammatory signaling pathways that lead to the production and activation of inflammatory cells, with cytokine production and oxidative stress. This inflammatory storm can cause damage to vital organs, especially the heart, and thus lead to complications in the postoperative period. In addition to the organic pathophysiology during and after the period of exposure to extracorporeal circulation, this review addresses new perspectives for intraoperative treatment and management that may lead to a reduction in this inflammatory storm and thereby improve the prognosis and possibly reduce the mortality of these patients.

A rare case report of one stage surgical treatment for left renal cell carcinoma with level IV intravenous tumor thrombus combined with severe coronary artery stenosis

RATIONALE

Renal cell carcinoma (RCC) exhibits a natural tendency to extend from the kidney into inferior vena cava (IVC) and growing into the right atrium is a rare complication. We report a 65-year-old patient with an RCC with intravascular extension through renal vein into the IVC and right atrial combined with severe coronary artery disease. This case has not been described in the literature and there is no treatment guideline for it.

PATIENT CONCERNS

A 65-year-old patient was admitted to our clinic with complaints of edema of both lower extremities.

DIAGNOSES

On the basis of the magnetic resonance imaging scan and coronary angiography, we strongly suspected an RCC with intravascular extension through renal vein into the IVC and right atrial combined with severe coronary artery disease.

INTERVENTIONS

We performed open left radical nephrectomy, IVC, and right atrium thrombectomy under cardiopulmonary bypass and coronary artery bypass grafting on beating heart.

OUTCOMES

The postoperative course was uneventful. The patient has been discharged from hospital.

LESSONS

Coexistence of severe coronary artery disease and RCC infiltrating inferior vena cava and right atrium rendered this operation as very high-risk procedure. We hope that our operational manners can prove the possibility of simultaneous difficult cardiac and urologic operation. The basic point of our report concerns the fact that the oncologic treatment was not delayed despite severe heart disease.

Simultaneous or staged surgery in patients with kidney tumors and concomitant cardiac disease

Introduction

To evaluate outcomes of simultaneous and staged surgery in patients with kidney tumors and concomitant cardiac disease.

Material and methods

Between October 2001 and October 2015, fifteen patients (Group 1) underwent simultaneous surgery and fourteen patients (Group 2) underwent staged surgery. 89.7% were males (26/29), and the mean age was 60.8 ±1.16 years. Locally advanced cancers (Stage III) were registered in the two groups in 11 vs. 3 patients (p = 0.016) and localized (Stage I) disease in 2 vs. 10 (p = 0.007), respectively. 18 patients (62%) were operated for coronary heart disease, while 10 patients (35%) underwent surgery for valvular heart disease. Nephrectomy was performed in 14rs 5 patients respectively (p = 0.003) while partial nephrectomy in 1rs 7 patients (p = 0.005).

Results

In the two groups, the 30-day mortality was 13% (2 cases) and 7% (1 case), p = 1.0, and major hospital complications were observed in 3 (20%) and 2 (14%) cases, respectively, p = 0.53. The median follow-up in Group 1 and Group 2 was 87 months (range, 23.3 to 146.8 months) and 39 months (range, 3.9 to 98 months), respectively, p = 0.001. Three-year overall survival was 73.3 ±11.4% (95% CI 50.5–96.1) and 77.9 ±11.3%, respectively, p = 0.70, and three-year disease-free survival was 83.9 ±10.4% and 75.0 ±21.7%, respectively, p = 0.91.

Conclusions

Simultaneous and staged surgery for kidney tumors and concomitant cardiac disease are feasible procedures. Patients with advanced tumors and complicated disease course can benefit from early intervention and consequently a simultaneous approach can be a preferred option for them. For localized renal tumors, staged surgery should be used.

Correlation Between Flow-Mediated Dilatation of the Brachial Artery and Serum Endothelial Biomarkers in the Evaluation of Acute Endothelial Injury After Cardiopulmonary Bypass

OBJECTIVES

The purpose of this study was to investigate the correlation between flow-mediated dilatation of the brachial artery and serum endothelial biomarkers and to discuss the feasibility of sonographic evaluation of acute endothelial injury during cardiopulmonary bypass (CPB) surgery.

METHODS

Sonography was applied to determine the percentage of change in the brachial artery size during flow-mediated dilatation. Meanwhile, the plasma concentrations of endothelial-derived biomarkers, such as endothelin 1, nitric oxide, and von Willebrand factor, were measured to monitor the changes in endothelial function. We analyzed the correlation between flow-mediated dilatation and biomarkers during the perioperative period of CPB in 27 patients.

RESULTS

All of the biomarkers changed dramatically, especially during the CPB period. There was a negative correlation between flow-mediated dilatation and von Willebrand factor (P = .001; R = -0.31).

CONCLUSIONS

A CPB event has a substantial impact on endothelial function, and sonographic assessment of the percentage of change in the brachial artery size during flow-mediated dilatation allows early detection of acute endothelial function injury in cardiac surgery.

Procalcitonin is useful whereas C-reactive protein is not, to predict complications following coronary artery bypass surgery

Background: The respective value of procalcitonin (PCT) and C-reactive protein (CRP) as markers of postoperative complications after coronary bypass surgery is unclear. Therefore, complications during one week after surgery were studied to evaluate the predictive role of PCT and CRP changes during the immediate postoperative period.

Methods: Thirty-two patients, in whom an uneventful immediate postoperative course was anticipated, were prospectively enrolled and followed-up to the 7th postoperative day. At the end of the follow-up, patients were divided into two groups. Group A were patients with an uncomplicated postoperative course and Group B were patients with a complicated postoperative course.

Results: Serum samples were drawn for PCT and CRP determination after induction of anesthesia (baseline), at the end of surgery and daily until postoperative day 2. Baseline serum PCT concentrations were 0.119 ± 0.09 and 0.209 ± 0.21 ng/mL in Groups A and B, respectively (NS). Serum PCT concentration increased compared with baseline in both groups during the first two days after surgery. The increase in serum PCT concentration was significantly greater in Group B than A patients ( p<0.0002). Considering a perioperative abnormal cut-off value of > 0.5 ng/mL, there were none in Group A versus 57% in Group B ( p<0.0001). Baseline serum CRP concentrations were 1.449 ± 1.30 and 1.589 ± 1.35 ng/mL in Groups A and B, respectively (NS). After surgery, CRP increased significantly compared with baseline in both groups. When changes in time-varying variables were included in a logistic model, complications were predicted by changes (between baseline and end of surgery values) of PCT (coefficient=9.410; t=2.18) and heart rate (coefficient=0.075; t=1.57), whereas changes of CRP, white blood cells, mean blood and central venous pressures did not contribute statistically. The model constant was -4.827 (t= -2.43) and the ROC curve area was 0.8971. Thus, absolute PCT changes of 0.20, 0.40 and 0.60 ng/mL carry an approximate risk of 5, 26 and 69%, respectively, of postoperative complications in the time frame of this study.

Conclusions: A postoperative serum PCT concentration of >0.5 ng/mL is highly suggestive of a postoperative complication. CRP changes do not contribute to predictive information.

Serum Immune Proteins in Moderate and Severe Chronic Fatigue Syndrome/Myalgic Encephalomyelitis Patients

Immunological dysregulation is present in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME), with recent studies also highlighting the importance of examining symptom severity. This research addressed this relationship between CFS/ME severity subgroups, assessing serum immunoglobulins and serum cytokines in severe and moderate CFS/ME patients. Participants included healthy controls (n= 22), moderately (n = 22) and severely (n=19) affected CFS/ME patients. The 1994 Fukuda Criteria defined CFS/ME and severity scales confirmed mobile and housebound CFS/ME patients as moderate and severe respectively. IL-1β was significantly reduced in severe compared with moderate CFS/ME patients. IL-6 was significantly decreased in moderate CFS/ME patients compared with healthy controls and severe CFS/ME patients. RANTES was significantly increased in moderate CFS/ME patients compared to severe CFS/ME patients. Serum IL-7 and IL-8 were significantly higher in the severe CFS/ME group compared with healthy controls and moderate CFS/ME patients. IFN-γ was significantly increased in severe CFS/ME patients compared with moderately affected patients. This was the first study to show cytokine variation in moderate and severe CFS/ME patients, with significant differences shown between CFS/ME symptom severity groups. This research suggests that distinguishing severity subgroups in CFS/ME research settings may allow for a more stringent analysis of the heterogeneous and otherwise inconsistent illness.

Resection of thoracic malignancies infiltrating cardiac structures with use of cardiopulmonary bypass

Background

Only few reports exist on malignant thoracic neoplasms that require cardiopulmonary bypass during resection. We aimed to investigate the early and late clinical outcome of these patients.

Methods

Patients with thoracic malignancies that underwent surgery between 2002 and 2014 were analyzed. All patients had cardiopulomonary bypass support during resection. Clinical and perioperative data was retrospectively reviewed for outcome and overall survival.

Results

Fifteen patients (12 female, mean age of 55 ± 15 years, range 24 to 80 years) were identified. Eleven (8 female) were diagnosed with primary thoracic malignomas and four with metastases. Three patients died early postoperatively. Patients diagnosed with sarcoma had a significantly worse outcome than non-sarcoma patients (83.3 ± 15.2 % after 1 year, 31.3 ± 24.5 % after 5 years vs. 83.3 ± 15.2 % after 1 year, 0 ± 0 % after 5 years, p = 0.005).

Conclusions

Malignancies with extension into cardiac structures or infiltration of great vessels can be resected with cardiopulmonary bypass support and tolerable risk. Carefully selected patients can undergo advanced operative procedures with an acceptable 1-year-survival, but only few patients achieved good long-term outcome.

The effects of cardiopulmonary bypass on pulmonary function during robotic cardiac surgery

BACKGROUND

We aimed to investigate the effects of cardiopulmonary bypass (CPB) on pulmonary function under the conditions of one-lung ventilation (OLV) and carbon dioxide pneumothorax in robotic cardiac surgery.

METHODS

Ninety-eight patients underwent robotic cardiac surgery using the da Vinci Surgical System, including 58 on-pump surgeries and 40 off-pump surgeries. Respiratory parameters and arterial blood gases were assessed at the following time points: 25 min after the induction of anesthesia under two-lung ventilation (T1), 25 min after OLV (T2), 25 min after the termination of CPB under OLV in the on-pump group or 25 min after the main surgery intervention in the off-pump group (T3) and 20 min before the end of surgery (T4). Dynamic lung compliance (Cdyn), alveolar-arterial PO2 difference (PA-aDO2), oxygenation index (OI) and artery-alveolar O2 pressure ratio (a/A) were calculated.

RESULTS

No significant differences in pulmonary function parameters between T2 and T3 were observed in the off-pump group. However, in the on-pump group, compared with those at T2, PETCO2, Ppeak, PaCO2 and PA-aDO2 at T3 were higher, whereas SpO2, Cdyn, PaO2, OI and a/A were lower (p<0.05). Comparisons between the two groups at T3 indicated that SpO2, Cdyn, PaO2, OI and a/A were higher, while Ppeak, PaCO2 and PA-aDO2 were lower in the off-pump group (p<0.01).

CONCLUSIONS

In robotic cardiac surgery under the conditions of OLV and carbon dioxide pneumothorax, CPB worsened pulmonary function and tolerance to OLV and carbon dioxide pneumothorax.

Fluid distribution kinetics during cardiopulmonary bypass

OBJECTIVE

The purpose of this study was to examine the isovolumetric distribution kinetics of crystalloid fluid during cardiopulmonary bypass.

METHODS

Ten patients undergoing coronary artery bypass grafting participated in this prospective observational study. The blood hemoglobin and the serum albumin and sodium concentrations were measured repeatedly during the distribution of priming solution (Ringer's acetate 1470 ml and mannitol 15% 200 ml) and initial cardioplegia. The rate of crystalloid fluid distribution was calculated based on 3-min Hb changes. The preoperative blood volume was extrapolated from the marked hemodilution occurring during the onset of cardiopulmonary bypass. Clinicaltrials.gov: NCT01115166.

RESULTS

The distribution half-time of Ringer's acetate averaged 8 minutes, corresponding to a transcapillary escape rate of 0.38 ml/kg/min. The intravascular albumin mass increased by 5.4% according to mass balance calculations. The preoperative blood volume, as extrapolated from the drop in hemoglobin concentration by 32% (mean) at the beginning of cardiopulmonary bypass, was 0.6-1.2 L less than that estimated by anthropometric methods (p<0.02). The mass balance of sodium indicated a translocation from the intracellular to the extracellular fluid space in 8 of the 10 patients, with a median volume of 236 ml.

CONCLUSIONS

The distribution half-time of Ringer's solution during isovolumetric cardiopulmonary bypass was 8 minutes, which is the same as for crystalloid fluid infusions in healthy subjects. The intravascular albumin mass increased. Most patients were hypovolemic prior to the start of anesthesia. Intracellular edema did not occur.

Robotic cardiac surgery: an anaesthetic challenge

Robotic cardiac surgery with the da Vinci robotic surgical system offers the benefits of a minimally invasive procedure, including a smaller incision and scar, reduced risk of infection, less pain and trauma, less bleeding and blood transfusion requirements, shorter hospital stay and decreased recovery time. Robotic cardiac surgery includes extracardiac and intracardiac procedures. Extracardiac procedures are often performed on a beating heart. Intracardiac procedures require the aid of peripheral cardiopulmonary bypass via a minithoracotomy. Robotic cardiac surgery, however, poses challenges to the anaesthetist, as the obligatory one-lung ventilation (OLV) and CO2 insufflation may reduce cardiac output and increase pulmonary vascular resistance, potentially resulting in hypoxaemia and haemodynamic compromise. In addition, surgery requires appropriate positioning of specialised cannulae such as an endopulmonary vent, endocoronary sinus catheter, and endoaortic clamp catheter under the guidance of transoesophageal echocardiography. Therefore, cardiac anaesthetists should have a working knowledge of these systems, OLV and haemodynamic support.

Intratracheal antitumor necrosis factor-α antibody attenuates lung tissue damage following cardiopulmonary bypass

The aim of this study is to investigate the protective effect and underlying mechanism of antitumor necrosis factor-α antibody (TNF-α Ab) on lung tissue injury after cardiopulmonary bypass (CPB). Twenty-eight healthy New Zealand white rabbits were randomly divided into four groups. Group I received only an open chest operation. Groups II-IV all received CPB. Furthermore, groups III and IV received post-CPB endotracheal intubation with phosphate buffered saline or TNF-α Ab (2400 pg/kg), respectively. Perioperative blood neutrophil count, TNF-α level, and malondialdehyde (MDA) levels were determined in both the right and left atriums. Lung water content, TNF-α messenger RNA, protein, apoptosis in situ, and pathomorphological changes were also measured. The results show that TNF-α Ab can significantly inhibit leukocyte accumulation, reduce secretion of TNF-α and MDA, decrease lung tissue apoptosis, and attenuate post-CPB pathomorphological changes. TNF-α Ab administration, however, cannot suppress the expression of TNF-α, suggesting that the protective effects of TNF-α Ab originate from inhibiting the numerous biological functions of TNF-α. Intratracheal TNF-α Ab administration demonstrates a notable protective effect against lung injury after CPB.

Simultaneous nephrectomy and coronary artery bypass grafting through extended sternotomy

Background

The advances in surgical techniques, resuscitation and anesthesiology support over the last years have allowed simultaneous thoracic and abdominal operations to be made for cancer and concomitant severe heart vessel disease relieving the patient from several diseases simultaneously and achieving long lasting remission or cure.

Clinical case

A simultaneous nephrectomy and coronary artery bypass grafting procedure through extended sternotomy is reported. A 63-year-old man with severe coronary artery disease was found to have renal carcinoma.

Diagnosis

Postoperative pathological investigation of the tumor revealed the presence of renal cell carcinoma pT3a N0 M0, G2. Coronarography revealed advanced three-vessel coronary artery disease.

Treatment

We successfully performed a simultaneous curative surgery for renal carcinoma and coronary artery bypass graft surgery under cardiopulmonary bypass using a novel technique of extended sternotomy. Simultaneous surgery thus appears to be a beneficial and safe approach for the treatment of coronary artery disease and resectable renal cancer in carefully selected patients.

Extracorporeal membrane oxygenation support for resection of locally advanced thoracic tumors

BACKGROUND

The international experience with resection of advanced thoracic malignancies performed with extracorporeal membrane oxygenation (ECMO) support is limited. We examined our results to assess the risks and benefits of this approach.

METHODS

We retrospectively analyzed all patients with thoracic malignancies who underwent tumor resection with ECMO support in our department between 2001 and 2010.

RESULTS

Nine patients (aged 21 to 71 years; mean, 54.8±7.5 years) underwent complex tracheobronchial resections (n=6) or resections of greater thoracic vessels (n=3) under venoarterial (VA) ECMO support. In 7 patients the underlying pathologic condition was non-small cell lung cancer, in 1 patient it was carcinoid tumor, and in 1 patient it was synovial sarcoma. The indication for extracorporeal support was complex tracheobronchial reconstruction (n=5), resection of the descending aorta (n=2), and resection of the inferior vena cava (n=1). ECMO cannulation was central (n=4), peripheral (n=4), or combined (n=1). Mean time on bypass was 110±19 minutes (range 40 to 135 minutes). A complete resection (R0) was achieved in 8 patients (89%). One patient died perioperatively as a result of hepatic necrosis. Eight patients were discharged from the hospital after 7 to 42 days (median, 10 days). Median time in the intensive care unit was 1 day (range, 0 to 36 days). The only complication related to the use of ECMO was a lymphatic fistula in the groin. Mean follow-up time was 38±42 months (range, 9 to 111 months). The actuarial 3-month survival was 88.9%, and the 1-year, 3-year, and 5-year survival was 76.7%.

CONCLUSIONS

Based on this experience, we consider VA ECMO support to be a safe alternative to cardiopulmonary bypass (CPB) for advanced general thoracic operations.

Renal carcinoma infiltrating inferior vena cava and combined valvular heart disease--one-stage uro-cardiological procedure: a case report

Standard treatment of patients with coexisting cardiac and non-cardiac diseases includes two separate operations. We report a case of 55-year-old man with combined valvular heart disease and renal carcinoma infiltrating inferior caval vein, who underwent one-stage cardio-urologic procedure. In the first step, mitral and tricuspid valvuloplasty were performed by cardiac surgeons. Then, urologists performed radical nephrectomy and thrombectomy. The postoperative course was uneventful. In twelve months follow-up the patient shows no signs of reccurrence and he had no symptoms of cardiac disease. To the best of our knowledge such a case has never been reported before in the literature.

Strategies to prevent intraoperative lung injury during cardiopulmonary bypass

During open heart surgery the influence of a series of factors such as cardiopulmonary bypass (CPB), hypothermia, operation and anaesthesia, as well as medication and transfusion can cause a diffuse trauma in the lungs. This injury leads mostly to a postoperative interstitial pulmonary oedema and abnormal gas exchange. Substantial improvements in all of the above mentioned factors may lead to a better lung function postoperatively. By avoiding CPB, reducing its time, or by minimizing the extracorporeal surface area with the use of miniaturized circuits of CPB, beneficial effects on lung function are reported. In addition, replacement of circuit surface with biocompatible surfaces like heparin-coated, and material-independent sources of blood activation, a better postoperative lung function is observed. Meticulous myocardial protection by using hypothermia and cardioplegia methods during ischemia and reperfusion remain one of the cornerstones of postoperative lung function. The partial restoration of pulmonary artery perfusion during CPB possibly contributes to prevent pulmonary ischemia and lung dysfunction. Using medication such as corticosteroids and aprotinin, which protect the lungs during CPB, and leukocyte depletion filters for operations expected to exceed 90 minutes in CPB-time appear to be protective against the toxic impact of CPB in the lungs. The newer methods of ultrafiltration used to scavenge pro-inflammatory factors seem to be protective for the lung function. In a similar way, reducing the use of cardiotomy suction device, as well as the contact-time between free blood and pericardium, it is expected that the postoperative lung function will be improved.

Statin prophylaxis and inflammatory mediators following cardiopulmonary bypass: a systematic review

Introduction

Induction of an inflammatory response is thought to have a significant role in the complications that follow cardiopulmonary bypass (CPB). The statin drugs are increasingly being recognized as having potent anti-inflammatory effects and hence have potential to influence an important mechanism of injury in CPB, although there is no current confirmation that this is indeed the case. Our objective was to systematically review if pre-operative prophylactic statin therapy, compared with placebo or standard of care, can decrease the inflammatory response in people undergoing heart surgery with CPB.

Methods

We performed a systematic and comprehensive literature search for all randomized controlled trials (RCTs) of open heart surgery with CPB in adults or children who received prophylactic statin treatment prior to CPB, with reported outcomes which included markers of inflammation. Two authors independently identified eligible studies, extracted data, and assessed study quality using standardized instruments. Weighted mean difference (WMD) was the primary summary statistic with data pooled using a random effects model. Descriptive analysis was used when data could not be pooled.

Results

Eight RCTs were included in the review, with the number of trials for each inflammatory outcome being even more limited. Pooled data demonstrated benefit with the use of statin to attenuate the post-CPB increase in interleukins 6 and 8 (IL-6, IL-8), peak high sensitivity C-reactive protein (hsCRP), and tumor necrosis factor-alpha (TNF-α) post-CPB (WMD [95% confidence interval (CI)] -23.5 pg/ml [-36.6 to -10.5]; -23.4 pg/ml [-35.8 to -11.0]; -15.3 mg/L [CI -26.9 to -3.7]; -2.10 pg/ml [-3.83 to -0.37] respectively). Very limited RCT evidence suggests that prophylactic statin therapy may also decrease adhesion molecules following CPB including neutrophil CD11b and soluble P (sP)-selectin.

Conclusions

Although the RCT evidence may suggest a reduction in post-CPB inflammation by statin therapy, the evidence is not definitive due to significant limitations. Several of the trials were not methodologically rigorous and statin intervention was highly variable in this small number of studies. This systematic review demonstrates that there is a significant gap that exists in the current literature in regards to the potential anti-inflammatory effect of statin therapy prior to CPB.

The inflammatory response to colloids and crystalloids used for pump priming during cardiopulmonary bypass

BACKGROUND

Systemic inflammatory response frequently occurs after coronary artery bypass surgery and is strongly correlated with the risk of postoperative morbidity and mortality. This study tests the hypothesis that the priming of the extracorporeal circuit with colloid solutions results in less inflammation in patients undergoing cardiac surgery than priming with crystalloid solutions.

METHODS

A prospective, randomized study was designed. Forty-four patients undergoing elective coronary artery bypass grafting were randomly allocated to one of two groups: 22 patients primed with Ringer's lactate (RL) solution and 22 patients primed with gelatin-containing solution during the surgery. Plasma levels of interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-alpha, C-reactive protein (CRP) and, complement 4 were measured during the surgical intervention and over the following 48 postoperative hours. Cytokine levels were measured by enzyme-linked assays from plasma samples obtained at specific time points pre- and post-operatively.

RESULTS

In both groups the serum levels of the pro-inflammatory cytokines (IL-6, IL-8, TNF-alpha), CRP, complement 4, and leukocytes increased significantly over the baseline, although no significant differences were observed between the two groups. The operation time, blood loss, need for inotropic support, extubation time, and length of intensive care unit stay did not differ significantly between the two groups.

CONCLUSION

Priming with gelatin vs. RL produces no significant differences in the inflammatory response in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass.

Influence of early re-infusion of autologous shed mediastinal blood on clinical outcome after cardiac surgery

Various strategies have been proposed to decrease allogeneic blood transfusion requirements after cardiac surgery. The aim of the study was to evaluate the efficacy of collected and re-infused autologous shed mediastinal blood on a patient's postoperative course. Ninety patients who underwent heart surgery with cardiopulmonary bypass (CPB) were studied. The patients were divided into two groups: Group 1 (n=41) received the centrifuged autologous shed mediastinal blood collected from the cardiotomy reservoir 4 hours after surgery; in Group 2 (n=49) all shed mediastinal blood was discarded (control group). Haemoglobin (Hb), haematocrit (Hct), C-reactive protein values, and leucocyte count were compared before surgery, at 4 h and 20 h after surgery, and on the fifth postoperative day. We have measured serum procalcitonin (PCT) concentration at 4 h and 20 h after CPB. We assessed drained blood loss within 20 postoperative hours. Leucocyte count, Hb, Hct values, C-reactive protein, and procalcitonin concentration did not differ between the groups before and at 4 h after surgery. Hb, Hct level, and leucocyte count were similar at 20 hours and on the fifth day after surgery. At 20 hours after surgery, an increase of serum PCT concentration (>0.5-2 ng/mL) was more frequent in Group 2 (58.3% vs. 33.3%; p = 0.03). On the fifth postoperative day, C-reactive protein concentration was lower in Group 1 (71.74 +/- 15.23; p <0.01) compared to Group 2 (93.53 +/- 20.3). Postoperative blood loss did not differ between the groups. Requirement for allogeneic blood transfusion was significantly lower in Group 1 (14.6% vs. 38.8%; p < 0.02). Patients in Group 1 developed less infective complications compared with Group 2 (2.4% and 16.3%, respectively; p < 0.05). The length of postoperative in-hospital stay was shorter in Group 1 compared with Group 2 (9.32 +/- 2.55 and 16.45 +/- 6.5, respectively; p < 0.05). We conclude that postoperative re-infusion of autologous red blood cells processed from shed mediastinal blood did not increase bleeding tendency and systemic inflammatory response and was effective in reducing the requirement for allogeneic transfusion, the rate of infective complications and the length of postoperative in-hospital stay.

Significance of peritoneal fluid drainage in management after repair of complex heart defects in infancy: cytokine dynamics in vivo

BACKGROUND

In vivo redundancy of pro-inflammatory cytokines results in a vicious cycle of systemic inflammatory response syndrome and low cardiac output syndrome (LOS). The purpose of this study was to elucidate the influence of peritoneal fluid (PF) drainage on cytokine dynamics in vivo and the significance of early induction for infants with LOS.

METHODS AND RESULTS

Seven infants, who underwent early PF drainage to manage LOS after repair of complex heart defects under cardiopulmonary bypass, were enrolled. The serum and PF levels of the pro- and antiinflammatory cytokines, interleukin (IL)-6, -8, -10 and tumor necrosis factor (TNF)-alpha, were measured during the perioperative period. Clinical outcomes were observed simultaneously. There were no cases of early or late death, or infectious complications. Drainage volume of PF peaked just after operation, and decreased completely. The amount of proinflammatory cytokines in the PF increased for 3 days after operation. Of the proinflammatory cytokines in the PF IL-6 increased the earliest and cleared the fastest. The amount of cleared IL-8 and TNF-alpha peaked on the 3rd postoperative day and resembled the course of C-reactive protein (CRP). Serum levels of CRP and proinflammatory cytokines in patients with PF drainage decreased significantly more than those without PF drainage.

CONCLUSIONS

Early initiation of PF drainage is useful in the postoperative critical care of infants with LOS by improving cytokine dynamics in vivo, although there are differences between the severity of patients undergoing PF drainage and those who do not.

Role of poly(ADP-ribose) polymerase during vascular reconstruction

Open vascular repair of ischemic myocardium and aortic aneurysms results in a systemic inflammatory response that influences the mortality and morbidity of these procedures. Recent studies in animal models of complex vascular reconstruction indicate that the activity of poly(ADP-ribose) polymerase (PARP) may influence the mortality and morbidity of these kinds of reconstructions. PARP's activity, localized to nuclei and mitochondria, is stimulated by deoxyribonucleic acid (DNA) strand breaks. Activation of PARP results in synthesis of poly(ADP-ribose) sugar moieties, whose primary role is to protect DNA from degradation during cytotoxic stress. Paradoxically, when stressful conditions similar to those experienced during vascular reconstructions result in overactivation of PARP, depletion of cellular levels of adenosine triphosphate and nicotinamide adenine dinucleotide can result in exacerbation of tissue injury. Herein we review the role of PARP in inflammation and its relevance to cardiovascular reconstructions.

Autologous lung used as a substitute of oxygenator in cardiopulmonary bypass can preserve postoperative respiratory function

We substituted autologous lung for the artificial oxygenator to assess reduction of lung injury after conventional cardiopulmonary bypass (CPB). Twelve piglets were randomly divided into two groups. Experimental animals (n = 6) underwent bilateral CPB with autologous lungs perfusion, whereas control animals (n = 6) underwent conventional CPB with artificial oxygenator. Bypass and aortic cross clamping time were 135 and 60 minutes, respectively, for each animal. Lung static compliance (Cstat), alveolus-artery oxygen difference (PA-aO2), tumor necrosis factor (TNF)-alpha, interleukin-6, and wet to dry lung weight ratio (W/D) were measured. A single senior pathologist evaluated the lung specimens after experiments. Cstat of experimental group and control group decreased from 14.31 +/- 1.58 to 12.88 +/- 1.92 ml/cmH2O and from 14.80 +/- 2.32 to 10.48 +/- 1.66 ml/cmH2O, respectively; PA-aO2 increased from 15.71 +/- 1.35 to 62.30 +/- 24.29 mm Hg and from 15.23 +/- 2.87 to 77.85 +/- 11.45 mm Hg, respectively; serum concentration of TNF-alpha increased from 0.40 +/- 0.07 ng/ml to 0.56 +/- 0.15 and from 0.41 +/- 0.06 to 0.75 +/- 0.14 ng/ml, respectively; and the w/d were 6.18 +/- 0.55 vs 6.84 +/- 0.30. Pathological examination also confirmed that structural changes of lung specimens were less in experimental group than in control group. Autologous lung may tolerate nonpulsatile perfusion and be used clinically as a substitute for the artificial oxygenator to reduce lung injury after CPB.

A Randomized Trial of Pulsatile Perfusion Using an Intra-Aortic Balloon Pump Versus Nonpulsatile Perfusion on Short-Term Changes in Kidney Function During Cardiopulmonary Bypass During Myocardial Reperfusion

BACKGROUND

Nonpulsatile perfusion during cardiopulmonary bypass can induce renal damage. We evaluated whether pulsatile perfusion using an intra-aortic balloon pump preserves renal function in patients undergoing myocardial revascularization.

STUDY DESIGN

Randomized controlled trial, nonmasked parallel-group design.

SETTING & PARTICIPANTS

100 patients undergoing preoperative perfusion using an intra-aortic balloon pump; 64 with baseline estimated glomerular filtration rate (eGFR) of 60 mL/min/1.73 m(2) or greater (>or=1 mL/s/1.73 m(2); stage 1 or 2) and 36 with eGFR of 30 to 59 mL/min/1.73 m(2) (0.5 to 0.98 mL/s/1.73 m(2); stage 3).

INTERVENTION

Patients were randomly assigned to nonpulsatile perfusion during cardiopulmonary bypass (group A) or automatic intra-aortic balloon pump-induced pulsatile perfusion during cardiopulmonary bypass (group B).

OUTCOMES & MEASUREMENTS

Renal function, daily diuresis, complications, serum lactate levels, and other biochemical indices at 24 and 48 hours.

RESULTS

GFR, adjusted for baseline eGFR, was 16 mL/min/1.73 m(2) [0.27 mL/s/1.73 m(2)] less in group A (58.1 mL/min/1.73 m(2); 95% confidence interval [CI], 56.1 to 60.1 mL/min/1.73 m(2) [0.97 mL/s/1.73 m(2); 95% CI, 0.94 to 1.0 mL/s/1.73 m(2)]) than in group B (74.0 mL/min/1.73 m(2); 95% CI, 72.0 to 76.1 mL/min/1.73 m(2) [1.23 mL/s/1.73 m(2); 95% CI, 1.20 to 1.27 mL/s/1.73 m(2)]; P < 0.001). Plasma lactate levels were +3.9 mg/dL (+0.43 mmol/L) higher in group A (19.5 mg/dL; 95% CI, 18.4 to 20.5 mg/dL [2.16 mmol/L; 95% CI, 2.04 to 2.28 mmol/L]) than in group B (16.7 mg/dL; 95% CI, 14.4 to 16.7 mg/dL [1.73 mmol/L; 95% CI, 1.60 to 1.85 mmol/L]; P < 0.001). No significant difference between the 2 groups was observed for 24-hour diuresis. Patients with eGFR stage 3 had a greater decrease in GFR and daily diuresis and greater increase in lactate levels than those with eGFR stages 1 to 2.

LIMITATIONS

Short-term change in kidney function as a surrogate outcome for "hard" clinical outcomes of mortality, morbidity, and length of hospitalization. Other limitations are short-term follow-up and absence of measurement of hemodynamic parameters or inflammatory mediators.

CONCLUSIONS

Use of automatic pulsatile intra-aortic balloon pumps during cardiopulmonary bypass is associated with better renal function during myocardial reperfusion. More studies are needed to verify the effects of pulsatile intra-aortic balloon pumps.

The hemodynamic effects of methylene blue when administered at the onset of cardiopulmonary bypass

Hypotension occurs during cardiopulmonary bypass (CPB), in part because of induction of the inflammatory response, for which nitric oxide and guanylate cyclase play a central role. In this study we examined the hemodynamic effects of methylene blue (MB), an inhibitor of guanylate cyclase, administered during cardiopulmonary bypass (CPB) to patients taking angiotensin-converting enzyme inhibitors. Thirty patients undergoing cardiac surgery were randomized to receive either MB (3 mg/kg) or saline (S) after institution of CPB and cardioplegic arrest. CPB was managed similarly for all study patients. Hemodynamic data were assessed before, during, and after CPB. The use of vasopressors was recorded. All study patients experienced a similar reduction in mean arterial blood pressure (MAP) and systemic vascular resistance (SVR) with the onset of CPB and cardioplegic arrest. MB increased MAP and SVR and this effect lasted for 40 minutes. The saline group demonstrated a persistently reduced MAP and SVR throughout CPB. The saline group received phenylephrine more frequently during CPB, and more norepinephrine after CPB to maintain a desirable MAP. The MB group recorded significantly lower serum lactate levels despite equal or greater MAP and SVR. In conclusion, administration of MB after institution of CPB for patients taking angiotensin-converting enzyme inhibitors increased MAP and SVR and reduced the need for vasopressors. Furthermore, serum lactate levels were lower in MB patients, suggesting more favorable tissue perfusion.

The role of complement in biomaterial-induced inflammation

Biomaterials are regularly used in various types of artificial tissues and organs, such as oxygenators, plasmapheresis equipment, hemodialysers, catheters, prostheses, stents, vascular grafts, miniature pumps, sensors and heart aids. Although progress has been made regarding bioincompatibility, many materials and procedures are associated with side effects, in particular bioincompatibility-induced inflammation, infections and subsequent loss of function. After cardiopulmonary bypass, coagulopathies can occur and lead to cognitive disturbances, stroke and extended hospitalization. Hemodialysis is associated with anaphylatoid reactions that cause whole-body inflammation and may contribute to accelerated arteriosclerosis. Stents cause restenosis and, in severe cases, thrombotic reactions. This situation indicates that there is still a need to try to understand the mechanisms involved in these incompatibility reactions in order to be able to improve the biomaterials and to develop treatments that attenuate the reactions and thereby reduce patients' discomfort, treatment time and cost. This overview deals with the role of complement in the incompatibility reactions that occur when biomaterials come in contact with blood and other body fluids.

Changes in Cerebral Vascular Reactivity Occur Early During Cardiopulmonary Bypass in the Rat

BACKGROUND

Cardiopulmonary bypass (CPB) is known to cause cerebrovascular dysfunction. The etiology of these complications is complex, but disruption of normal cerebral endothelial function as a consequence of inflammatory or hypoperfusion phenomena have been implicated. The aim of this study was to investigate the effect of CPB time on cerebrovascular reactivity and to investigate the correlation of these findings with measured inflammatory markers.

METHODS

Cardiopulmonary bypass was carried out for 30 or 60 minutes on two groups of rats. Sham groups underwent the same surgical procedure without CPB. The middle cerebral artery was harvested and prepared for assessment of induced endothelial and vascular smooth muscle cell responses. Systemic inflammation was evaluated by measuring tumor necrosis factor-alpha and immunohistochemical staining for intercellular adhesion molecule-1.

RESULTS

Acetylcholine caused a dose-dependent vasodilation in the control groups that was absent in animals undergoing CPB (21.3% +/- 1.3% increase in diameter at 30 minutes in the sham group compared with 5.4% +/- 1.1% in the corresponding CPB group, p < 0.001). Significantly, this was apparent after only 30 minutes of CPB. Cardiopulmonary bypass did not alter the response to sodium nitroprusside (45.3% +/- 8.6% after 30 minutes in the sham group compared with 57.8% +/- 8.0% in the corresponding CPB group, p < 0.2). Furthermore, the contractile response to serotonin remained intact in all groups (32.9 +/- 4.6 and 27.6 +/- 2.6 at 30 and 60 minutes, respectively, in the sham groups compared with 23.1 +/- 1.6 and 28.0 +/- 4.4 in the corresponding CPB groups, p < 0.2). Cardiopulmonary bypass also led to an early and marked increase in tumor necrosis factor-alpha and overexpression of intercellular adhesion molecule-1.

CONCLUSIONS

Cerebrovascular impairment appears early after the onset of CPB. The specific loss of acetylcholine-induced vasodilation suggests endothelial cell dysfunction rather than impaired vascular smooth muscle response to nitric oxide. This loss of endothelium-dependent regulatory factors after CPB may enhance vasoconstriction, impair cerebrovascular function, and contribute to neurologic injury after CPB.

Effects of atorvastatin on systemic inflammatory response after coronary bypass surgery

OBJECTIVES

Systemic inflammatory response occurs frequently after coronary artery bypass surgery, and it is strongly correlated with the risk of postoperative morbidity and mortality. Recent studies demonstrate that treatment with statin is associated with a significant and marked decrease in inflammation-associated variables such as the C-reactive protein, cytokines, and adhesion molecules. Therefore, we investigated the effects of preoperative atorvastatin treatment on systemic inflammatory response and perioperative morbidity after cardiopulmonary bypass.

DESIGN

Double-blinded, placebo-controlled, randomized study.

SETTING

University hospital.

PATIENTS

Forty patients were randomized to treatment with atorvastatin (20 mg/day, group A, n=20) or placebo (group B, n=20) 3 wks before surgery.

INTERVENTIONS

Three-week treatment by atorvastatin 20 mg/day.

MEASUREMENT AND MAIN RESULTS

Postoperative serum levels of both interleukin-6 and interleukin-8 increased significantly over baseline, but the peak levels observed 4 hrs postoperatively were significantly lower in the atorvastatin group. In the same fashion, CD11b expression on neutrophils was significantly lower in the statin group at 4 and 24 hrs postoperatively. Finally, neutrophil-endothelial adhesion was significantly reduced in the statin patients compared with controls. The operation time, blood loss, need for inotropic support, intubation time, and length of intensive care unit or hospital stay did not differ significantly between the two groups. The systemic inflammatory response syndrome score on postoperative days 1 and 2 was comparable in both groups.

CONCLUSIONS

Pretreatment with atorvastatin significantly reduces cytokine release and neutrophil adhesion to the venous endothelium in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass.

Should We Discontinue Intraaortic Balloon During Cardioplegic Arrest? Splanchnic Function Results of a Prospective Randomized Trial

BACKGROUND

Preoperative use of intraaortic balloon pumping (IABP) has increased in high-risk patients. Linear flow during cardiopulmonary bypass (CPB) can induce subclinical damage, whereas automatic IABP mode may maintain pulsatile flow. We sought to evaluate differences between suspending IABP and switching it to an automatic 80 bpm mode during cardioplegic arrest.

METHODS

Between January and November 2004, 40 patients undergoing preoperative IABP were randomized to receive either standard nonpulsatile CPB with IABP discontinued during cardioplegic arrest (20 patients; group A) or IABP-induced pulsatile (automatic 80 bpm) CPB (20 patients; group B). Hospital outcome was recorded. Urine output, blood urea nitrogen (BUN), creatine, creatinine clearance, peripheral lactate, recovery of gut motility, alanine-amino-transferase (ALT), aspartate-amino-transferase (AST), lactic dehydrogenase (LDH), bilirubin, and amylase (AMY) were compared.

RESULTS

There were no IABP-related complications, nor perioperative renal or liver failures, nor hospital deaths, nor myocardial infarctions. Intensive care and hospital stay, urine output, and recovery of gut motility were comparable. Group B showed lower creatine on the first (p = 0.01) and second (p = 0.005) postoperative days, higher creatinine clearance (first day: p = 0.01; second day: p = 0.03), lower lactate after CPB termination (p = 0.0001) and during the first day (p = 0.001). The ALT, AST, and AMY were lower in group B (first day ALT: p = 0.01; AST: p = 0.04; AMY: p = 0.017; second day ALT: p = 0.01; AST: p = 0.02; AMY: p = 0.027), as well as total bilirubin (first day: p = 0.05; second day: p = 0.02).

CONCLUSIONS

Automatic 80 bpm IABP during cardioplegic arrest improves creatinine clearance and splanchnic enzymes. There is no reason to suspend preoperative IABP support during cardioplegic arrest.

Leukocyte mitochondrial alterations after cardiac surgery involving cardiopulmonary bypass: clinical correlations

Cardiac surgery with the use of cardiopulmonary bypass (CPB) is known to initiate systemic inflammatory responses that are associated with immune dysregulations, but the pathomechanisms underlying these changes remain elusive. Mitochondrial transmembrane potential (MTP) is an important determinant of leukocytic functions and viability, and may be altered as a part of the cellular responses to systemic inflammatory insults. Therefore, we examined MTP in three subsets of peripheral leukocytes in 18 patients receiving uncomplicated cardiac surgery involving CPB. The MTP of neutrophils and lymphocytes significantly increased, whereas that of monocytes significantly declined, after the surgery. The alterations in leukocytic MTP were transient, normalizing 3 days to 1 week after the surgery, and were accompanied by transient overproduction of intracellular oxidants, including nitric oxide and superoxide. Despite these perturbations, the viability status of leukocytes remained unaltered. Positive correlations were found between the changes of leukocyte MTP and various clinical parameters, implying that leukocyte mitochondrial alterations are parts of the systemic immune perturbations induced by the bypass surgery.

Transdiaphragmatic-intrapericardiac approach to supradiaphragmatic vena cava invasion secondary to renal cell carcinoma: A novel surgical approach

INTRODUCTION

A combined abdominal and thoracic surgical approach is the treatment of choice for renal cell carcinoma with secondary thrombus extending to the supradiaphragmatic vena cava and initially into the right atrium. This procedure usually requires a median sternotomy with cardiopulmonary bypass and deep hypothermic circulation arrest or, alternatively, venovenous bypass. In this report, we present a transdiaphragmatic-intrapericardiac approach to supradiaphragmatic thrombus extending to the atrium that avoids the disadvantages, mortality, and morbidity related to cardiopulmonary bypass and deep hypothermic circulatory arrest or venovenous bypass.

TECHNIQUE

We describe a combined abdominal and transdiaphragmatic-intrapericardiac approach that was performed in 3 patients with renal cell carcinoma with secondary thrombus extending to the atrium. The estimated blood loss of the patients ranged from 1.1 to 2.8 L (mean 1.5). The total operative time ranged from 3 hours, 20 minutes to 4 hours. No postoperative complications were observed in any patient.

CONCLUSIONS

This technique allows excellent exposure of the supradiaphragmatic inferior vena cava through a 10-cm incision and optimal control of the distal thrombus edge when it reaches the right atrium. This approach is safer, faster, easier, and minimally invasive and avoids cardiopulmonary bypass with deep hypothermic cardiac arrest or venovenous bypass.

Effects of Ketamine on Serum and Tracheobronchial Aspirate Interleukin-6 Levels in Infants Undergoing Cardiac Surgery

OBJECTIVE

Corrective surgery for congenital heart defects in children frequently requires cardiopulmonary bypass (CPB). Serum and bronchoalveolar levels of interleukin-6 (IL-6) may be useful in assessing the severity of the systemic inflammatory response after CPB. In the present study, the authors aimed to compare the effects of ketamine anesthesia and isoflurane anesthesia with respect to serum and tracheobronchial aspirate (TBA) IL-6 levels in infants undergoing CPB for cardiac surgery.

DESIGN

Prospective and randomized controlled study.

SETTING

University-based teaching hospital.

PARTICIPANTS

Thirty-four infants aged 2 to 24 months were randomized into 2 groups.

INTERVENTIONS

In group K (n = 17), anesthesia was induced with intravenous (IV) ketamine, 1 to 2 mg/kg, and fentanyl, 1 to 2 microg/kg, and was maintained with infusions of ketamine, 25 to 75 microg/kg/min, and fentanyl, 10 microg/kg/h. In group I (n = 17), induction was achieved with IV thiopental sodium, 3 to 5 mg/kg, and fentanyl, 1 to 2 microg/kg, and was maintained with 1% isoflurane and fentanyl, 10 mug/kg/h. Blood and TBA samples were obtained at 6 and 4 stages, respectively.

MEASUREMENTS AND MAIN RESULTS

Serum IL-6 and TBA IL-6 levels were similar in the 2 groups at all stages (p > 0.05).

CONCLUSION

The present results show that ketamine anesthesia does not provide superiority over isoflurane anesthesia with respect to serum and TBA IL-6 levels.

Combined cardiothoracic surgery and interventions of the para/thyroid gland. A rare clinical cooperation

OBJECTIVE

Simultaneous cardiothoracic and general surgical interventions are still a matter of controversy. We investigated the question whether combined open heart surgery or thoracic surgery and interventions of the parathyreoid respectively thyroid gland may be helpful for the patients.

PATIENTS AND METHODS

The records of six patients (age range: 29-78 years) undergoing simultaneous cardiothoracic and para-/thyroid interventions were examined. Cardiothoracic surgery consisted in three patients of coronary artery bypass grafting, in one of aortic valve replacement, in one of thymus resection and finally in one of resection of a mediastinal Hodgkin's lymphoma. In combination with these procedures three patients underwent a subtotal goiter resection, two patients had a resection of a parathyroid adenoma and one patient underwent a right-sided hemithyroidectomy.

RESULTS

One patient died in the early postoperative course due to global myocardial failure on the base of preoperatively existing reduced left ventricular function. The other postoperative courses were uneventful. The duration of operation was between 165 and 687 min, perfusion time in case of open heart surgery was between 92 and 311 min, ischemic time ranged from 45 to 62 min. The length of hospital-stay ranged from 9 to 26 days. The postoperative follow-up showed all five patients to be in a satisfactory cardiovascular condition. There were no signs of recurrence of either para-/thyroid or Hodgkin's disease.

CONCLUSIONS

The postoperative course does not indicate an increased number of complications, although the total duration of operation and anesthesia is prolonged. Thus we conclude that simultaneous cardiothoracic and endocrine surgery of the para-/thyroid gland can be performed with acceptable risk in cases of preoperative low-risk assessment.

Changes in mesenteric vascular reactivity and inflammatory response after cardiopulmonary bypass in a rat model

BACKGROUND

Mesenteric ischemia and acidosis leading to intestinal ischemia has been observed during cardiopulmonary bypass (CPB) despite normal flow in the mesenteric vessels. The aim of this study was to assess mesenteric endothelium-dependent reactivity and vasoconstrictor responses of small mesenteric arteries in a rat model of CPB without aortic cross-clamping.

METHODS

After femoral cannulation a partial 90 minutes CPB was performed with hemodynamics and blood gas parameters monitoring. Blood samples and segments of small mesenteric arteries were obtained in rats sacrificed 2.5 hours (CPBH2.5) or 6 hours (CPBH6) after femoral cannulation. Sham surgery (sham H2.5, sham H6) was performed with femoral cannulation only. Segments of small mesenteric arteries were placed in a myograph in order to assess the contractile response to phenylephrine (with or without NO synthase inhibitor) or the endothelium-dependent relaxation to acetylcholine. Systemic inflammation was evaluated by measuring plasma concentrations of TNFalpha. Pulmonary and intestinal infiltration of activated leukocytes was assessed by immunohistochemistry.

RESULTS

CPB induced increased contractile response to phenylephrine which persisted after blockade of NO synthesis as well as transient impairment of endothelium-dependent relaxations. CPB also led to early and marked release of TNFalpha.

CONCLUSIONS

CPB was responsible for mesenteric endothelial dysfunction and direct increase in the contractile response to alpha1-adrenergic agonist with increased systemic inflammatory response. This phenomenon might contribute to an increase in the risk of mesenteric ischemic events during cardiac surgery especially when vasopressor agents are used.

Differential-display polymerase chain reaction identifies nicotinamide adenine dinucleotide-ubiquinone oxidoreductase as an ischemia/reperfusion-regulated gene in cardiomyocytes

OBJECTIVE

Cardiac ischemia/reperfusion-induced oxidative damage often occurs in mitochondria. We identified differentially expressed genes in the canine heart after global cardiac ischemia/reperfusion injury was induced during cardiopulmonary bypass (CPB).

METHODS

Differential-display polymerase chain reaction (ddPCR) was performed on cardiac tissue from canine hearts with or without global cardiac ischemia/reperfusion injury induced during CPB. Ischemia/reperfusion-associated mitochondrial injury was investigated at the protein level using various cardioplegic solutions and Western blot analysis.

RESULTS

A mitochondrial protein nicotinamide adenine dinucleotide (NADH):ubiquinone oxidoreductase gene was identified on ddPCR. The NADH:ubiquinone oxidoreductase gene was up-regulated in canine hearts after 60 min of global cardiac ischemia/reperfusion injury during CPB. Western blot analysis revealed that, after manipulation with different cardioplegic solutions, increased Bcl-2 expression and decreased cytochrome c expression were associated with cardiomyocytic apoptosis.

CONCLUSIONS

The NADH:ubiquinone oxidoreductase gene is up-regulated during global cardiac ischemia/reperfusion injury during CPB in canines. To our knowledge, involvement of this gene in global cardiac ischemia/reperfusion injury during CPB has not been described previously. The NADH:ubiquinone oxidoreductase gene may have a role in the regulation of molecular changes during the global cardiac ischemia/reperfusion injury during CPB, such as the up-regulation of Bcl-2, which might block release of cytochrome c from the mitochondria and prevent cardiomyocytic apoptosis.

Cardiopulmonary bypass in man: role of the intestine in a self-limiting inflammatory response with demonstrable bacterial translocation

BACKGROUND

Cardiopulmonary bypass provokes a systemic inflammatory reaction that, in 1% to 2% of all cases, leads to multiorgan disfunction. The aim of this study was to evaluate the possible role of the intestine in the pathogenesis and development of this reaction.

METHODS

Eleven selected patients scheduled for elective coronary artery bypass graft surgery were enrolled in a open, prospective clinical study. Gastric tonometry, chromium-labeled test and double sugar intestinal absorption tests, polymerase chain reaction microbial DNA test, and measurement of cytokines and transcriptional factor (nuclear factor kappaB) activation were performed.

RESULTS

During the postoperative period, gastric pH remained stable (range,7.2 to 7.3). The partial pressure for carbon dioxide gradient between the gastric mucosa and arterial blood increased significantly (from 1 to 23 mm Hg), peaking in the sixth postoperative hour. Interleukin 6 increased significantly over basal levels, peaking 3 hours after cardiopulmonary bypass (96.3 versus 24 pg/mL). Nuclear factor kappaB never reached levels higher than those observed after lipopolysaccharide stimulation. Escherichia coli translocation was documented in 10 patients: in eight cases from removal of aortic cross-clamps and in two cases from the first postoperative hour. With respect to basal value (6.4%), the urine collection revealed a significant increase in excretion of the radioisotope during the first 24 hours after surgery (39.1%), although there were no significant variations with the double sugar test.

CONCLUSIONS

The results obtained showed a correlation between the damage of the gastrointestinal mucosa, subsequent increased permeability, E coli bacteremia, and the activation of a self-limited inflammatory response in the absence of significant macrocirculatory changes and postoperative complications.

Antifibrinolytic therapy during cardiopulmonary bypass reduces proinflammatory cytokine levels: a randomized, double-blind, placebo-controlled study of ϵ-aminocaproic acid and aprotinin

OBJECTIVES

Aprotinin is a broad-spectrum serine protease inhibitor that has been shown to attenuate the systemic inflammatory response in patients undergoing cardiac surgery with cardiopulmonary bypass. Although epsilon-aminocaproic acid is similar to aprotinin in its ability to inhibit excessive fibrinolysis (ie, plasmin activity and D-dimer formation), its ability to influence proinflammatory cytokine production remains unclear. This study was designed to compare the effects of epsilon-aminocaproic acid and aprotinin on plasma levels of interleukin-6 and interleukin-8 during and after cardiopulmonary bypass.

METHODS

Sixty patients were randomized in a double-blind fashion to receive epsilon-aminocaproic acid, aprotinin, or saline (placebo) in similar dosing regimens (loading dose, pump prime, and infusion). Arterial blood samples were collected before, during, and after cardiopulmonary bypass, and plasma levels of D-dimer, interleukin-6, and interleukin-8 were measured. Data were analyzed using repeated measures analysis of variance.

RESULTS

Both epsilon-aminocaproic acid and aprotinin administration resulted in significant (P <.05) reductions in D-dimer and interleukin-8 levels compared with saline. These reductions in D-dimer and interleukin-8 levels did not differ between the 2 drug-treated groups. The effect of these two antifibrinolytic agents on interleukin-6 was qualitatively similar to that noted with interleukin-8 but did not reach statistical significance.

CONCLUSIONS

When dosed in a similar manner, epsilon-aminocaproic acid seems to be as effective as aprotinin at reducing interleukin-6 and interleukin-8 levels in patients undergoing primary coronary artery bypass graft surgery. These data indicate that suppression of excessive plasmin activity or D-dimer formation or both may play an important role in the generation of proinflammatory cytokines during and after cardiopulmonary bypass.

The systemic inflammatory response to cardiopulmonary bypass

Although our understanding of the basic pathophysiology of systemic inflammatory response to CPB has significantly advanced in the last 2 decades, these experimentally derived ideas have yet to be fully integrated into clinical practice. Treatment of the systemic inflammatory response to CPB is also confounded by the fact that inhibition of inflammation might disrupt protective physiologic responses or result in immunosuppression. Although it is unlikely that no single therapeutic strategy will ever be sufficient in of itself to totally prevent CPB-associated morbidity, the combination of multiple pharmacologic and mechanical therapeutic strategies, each selectively targeted at different components of the inflammatory response, may eventually result in significantly improved clinical outcomes following cardiac surgery.

Microvascular Inflammatory Response in Cardiac Surgery

Cardiac surgical procedures, with or without cardiopulmonary bypass, elicit a systemic inflammatory response in patients that induces the elaboration of multiple cytokines, chemokines, adhesion molecules, and destructive enzymes. This inflammatory reaction involves multiple interdependent and redundant cell types and humoral cascades, which allows for amplification and positive feedback at numerous steps. This systemic inflammatory response ultimately results in a broad spectrum of clinical manifestations, with multiple organ failure being the most severe form. Investigative efforts have focused on understanding the mechanism of this systemic inflammatory response syndrome in order to develop potential therapeutic targets to inhibit it, thereby possibly decreasing postoperative morbidity and mortality. Multiple therapeutic methods have been investigated, including pharmacologic inhibitors and modifications of surgical technique and the cardiopulmonary bypass circuit. Although studies have demonstrated that the use of these therapies in experimental and clinical settings has attenuated the systemic inflammatory response, they have failed to conclusively show clinical benefit from these therapies. These therapies may be too specific to minimize the deleterious effects of a systemic inflammatory response that results from the activation of multiple, interdependent, and redundant inflammatory cascades and cell types. Hence, further studies that investigate the molecular and cellular events underlying the systemic inflammatory response syndrome and the resultant effects of anti-inflammatory therapies are warranted to ultimately achieve improvements in clinical outcome after cardiac surgical procedures.

Do S100beta protein level increases due to inflammation during cardiopulmonary bypass occur without any neurological deficit?

PURPOSE

S100beta protein level correlates with the duration of cardiopulmonary bypass (CPB) and aortic crossclamp times, but is different during pulsatile and nonpulsatile CPB. In this study, we investigated the time course of the release of S100beta protein during and after pulsatile and nonpulsatile CPB.

PATIENTS AND METHODS

This is a prospective study. Twenty patients had open-heart surgery with pulsatile flow and 20 with nonpulsatile flow. We compared complement proteins, interleukins, white blood cells and S100beta protein before the initiation of CPB, immediately prior to aortic crossclamping, following unclamping, and at postoperative 1st and 24th hours.

RESULTS

In the pulsatile CPB group following aortic unclamping, S100beta protein (p = 0.028) and C3a (p = 0.011) levels were significantly lower than those of the nonpulsatile group. In the pulsatile CPB group at postoperative first hour, C3a level (p = 0.018) and absolute neutrophil count (p = 0.034) were significantly lower than those of the nonpulsatile group. None of the patients developed a neurological deficit and all of the patients survived after the operation and were discharged from the hospital.

CONCLUSION

During CPB, serum S100beta protein level increases and this increase is higher in the nonpulsatile group. High serum level of S100beta protein is associated with increased levels of serum inflammatory mediators and systemic inflammatory response.

Complement activation and cytokine and chemokines release during mediastinitis

BACKGROUND

Mediastinitis after open heart operation is an infrequent, but life-threatening complication with a reported incidence rate between 1% and 4%. Hospital mortality is estimated at 10% to 35%. The aim of the present work was to study the systemic inflammatory reaction as judged by complement activation and cytokine and chemokines release in patients with mediastinitis after open heart operation.

METHODS

Seven patients with clinical signs of mediastinitis were included. Three patients had undergone coronary artery bypass grafting, whereas 4 patients had combined coronary artery bypass grafting, valve replacement, or valvuloplasty. Blood samples were drawn before induction of anesthesia and at the time of reoperation, and thereafter daily during the hospital stay. Controls comprised similar patients with an uneventful postoperative course.

RESULTS

The terminal SC5b-9 complement complex concentration in the mediastinitis patients was substantially higher compared with the controls (p < 0.001), and the terminal SC5b-9 complement complex values showed no overlap between the two groups. Interleukin-8, stromal cell-derived factor-1alpha and IL-6 concentrations were also significantly higher in the mediastinitis group than in the control group (p < 0.001), but with considerable overlap between the groups. Interleukin-1beta, interleukin-10, and monocyte chemoattractant protein-1 concentrations were slightly higher in the mediastinitis group, and no differences were seen for the tumor necrosis factor-alpha.

CONCLUSIONS

During mediastinitis, the complement is activated and the cytokines and chemokines, interleukin-6, interleukin-8, and stromal cell-derived factor-1alpha are released. These proteins may be involved in the pathogenesis of this complication. Terminal SC5b-9 complement complex may be an indicator to discriminate mediastinitis patients from those with uneventful course.