Expression of soluble endothelial adhesion molecules in clinical cardiopulmonary bypass

Effects of Intraoperative Support Strategies on Endothelial Injury and Clinical Lung Transplant Outcomes

In lung transplantation, postoperative outcomes favor intraoperative use of extracorporeal membrane oxygenation (ECMO) over cardiopulmonary bypass (CBP). We investigated the effect of intraoperative support strategies on endothelial injury biomarkers and short-term posttransplant outcomes. Adults undergoing bilateral lung transplantation with No-Support, venoarterial (V-A) ECMO, or CPB were included. Plasma samples pre- and post-transplant were collected for Luminex assay to measure endothelial injury biomarkers including syndecan-1 (SYN-1), intercellular adhesion molecule-1 (ICAM-1), and matrix metalloprotease-9. Fifty five patients were included for analysis. The plasma level of SYN-1 at arrival in the intensive care unit was significantly higher with CPB compared to V-A ECMO and No-Support (P < 0.01). The rate of primary graft dysfunction grade 3 (PGD3) at 72 hours was 60.0% in CPB, 40.1% in V-A ECMO, and 15% in No-Support (P = 0.01). Postoperative plasma levels of SYN-1 and ICAM-1 were significantly higher in recipients who developed PGD3 at 72 hours. SYN-1 levels were also significantly higher in patients who developed acute kidney injury and hepatic dysfunction after transplant. Postoperative, SYN-1 upon intensive care arrival was found to be a significant predictive biomarker of PGD3, acute kidney injury, and hepatic dysfunction following lung transplantation. CPB is associated with higher plasma concentrations of SYN-1, a marker of endothelial glycocalyx degradation, upon arrival to the intensive care unit. Higher levels of SYN-1 are predictive of end-organ dysfunction following lung transplantation. Our data suggests that intraoperative strategies aimed at modulating endothelial injury will help improve lung transplantation outcomes.

Alterations in biomarkers of endothelial function following on-pump coronary artery revascularization

BACKGROUND

Cardiopulmonary bypass (CPB) has been associated with activation and injury of endothelial cells, probably responsible for the systemic inflammatory response syndrome (SIRS) taking place in these patients.

METHODS

We measured plasma concentrations of soluble P-selectin (sP-s), E-selectin (sE-s), tetranectin (TN), vonWillebrand factor (vWF) levels, and angiotensin-converting enzyme (ACE) activity in 31 adult patients undergoing elective coronary artery bypass grafting, just before and up to three days after surgery, and in 25 healthy volunteers.

RESULTS

Patients showed higher plasma sP-s and sE-s and ACE concentrations, just before surgery, but significantly lower TN levels, compared with controls. During the first three postoperative days (PD), the concentration of each of the molecules followed a different and independent pattern, although in the third PD, the levels of sP-s, sE-s and ACE were higher and those of vWF and TN lower, compared with the preoperative ones. However, patients had higher sP-s (P=0.06), sE-s (P=0.07), and vWF (P=0.005), but lower TN concentrations (P=0.02) on the third PD compared with controls.

CONCLUSIONS

CPB is characterised by pronounced changes in plasma sP-s, sE-s, TN, vWF levels, and ACE activity, which are associated with significant alteration in the intra- and early postoperative endothelial function observed in open heart surgery.

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.

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.

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.

Soluble adhesion molecules in coronary artery bypass surgery

Plasma levels of sE-selectin, sP-selectin, and sICAM-1 were measured before anesthesia and at 0.5, 4, and 20 hours after cardiopulmonary bypass in 37 men undergoing coronary artery bypass surgery. Plasma sE-selectin remained close to the preoperative levels. The levels of sP-selectin increased significantly from 46.5 +/- 15.3 ng x mL(-1) to 69.3 +/- 39.6 ng x mL(-1) at 0.5 hours, 84.1 +/- 45.5 ng x mL(-1) at 4 hours, and 79.6 +/- 35.5 ng x mL(-1) at 20 hours. Plasma sICAM-1 levels decreased 0.5 hours after cardiopulmonary bypass, recovered at 4 hours, and showed a significant increase at 20 hours. The changes in plasma levels of adhesion molecules did not correlate with the duration of bypass or aortic crossclamping, hemodynamics, or creatine kinase-MB levels. However, sE-selectin and sICAM-1 levels increased considerably more in patients who needed norepinephrine in the intensive care unit. These results indicate that the transient changes in plasma levels of soluble adhesion molecules are not associated with postoperative myocardial injury in low-risk coronary grafting, although they correlate with the need for a vasopressor.

Lung perfusion with protective solution relieves lung injury in corrections of Tetralogy of Fallot

BACKGROUND

The aim of this study was to evaluate the protective effect of pulmonary perfusion with hypothermic protective solution on lung function after cardiopulmonary bypass in corrections of Tetralogy of Fallot.

METHODS

Sixty-four consecutive children with Tetralogy of Fallot were randomly divided into a control group (n = 30) and a protective group (n = 34). Hypothermic protective solution was infused to the main pulmonary artery in the protective group. Hemodynamics and lung functions were monitored. Concentrations of malondialdehyde, tumor necrosis factor-alpha, von Willebrand factor, and endothelin in plasma were measured. The interleukin-6 and interleukin-8 levels in bronchoalveolar lavage fluid were also determined. Lung biopsy specimens were obtained after weaning from cardiopulmonary bypass.

RESULTS

Oxygenation values (oxygen index and alveolar-arterial O(2) gradient) were better preserved in the protective group than in the control group. The time of mechanical ventilation and length of intensive care unit stay were shorter in the protective group compared with the control group. The tumor necrosis factor-alpha and malondialdehyde levels in plasma increased in both groups after operations, and the rising extents were lower in the protective group than in the control group. The von Willebrand factor and endothelin levels in plasma increased more significantly in the control group than in the protective group. The concentrations of interleukin-6 and interleukin-8 in bronchoalveolar lavage fluid were lower in the protective group than in the control group. The examination of histopathology demonstrated capillary hyperemia and hemorrhage, intra-alveolar edema, leukocytes accumulation, mitochondria swelling and vacuolation, and gas-blood barrier broadening in the control group, whereas there were no significant changes in the protective group. The intercellular adhesion molecule-1 expression on lung vascular endothelial cells was stronger in the control group.

CONCLUSIONS

Lung perfusion with hypothermic protective solution during cardiopulmonary bypass relieved lung injury in corrections of Tetralogy of Fallot. The inhibition of lung vascular endothelial cell injury may be the major mechanism of relieving cardiopulmonary bypass-induced lung injury.

Monocyte activation markers during cardiopulmonary bypass

Extracorporeal support during cardiac surgery initiates an inflammatory response, causing damage to cardiac, pulmonary and renal tissue [Post Pump Syndrome (PPS)]. This is accompanied by a neutrophil leucocytosis and lymphopenia, but less is known about the role of monocytes and markers of monocyte activity. We studied 19 patients undergoing cardiac surgery, obtaining blood samples from the aortic root (AR) and from the coronary sinus ( < s) before the cardiopulmonary bypass (CPB), 1 min after release of the aortic crossclamp and 10 min after weaning from CPB (periods 1, 2 and 3). Leucocyte count, monocyte count and HLA-DR, CD15, CD11b and CD62L activation markers were measured. In samples obtained from the coronary sinus (CS), HLA-DR, expressed as a percentage of the monocyte count, decreased between periods 1, 2 and 3 by 78%, 66% and 43%, respectively. A similar change was observed in samples from the AR. Conversely, CD62L increased in the CS samples (55%, 68% and 73%), but revealed a lesser increase in the AR samples (51%, 68% and 63%). The other markers showed little change throughout the procedure. Reduced immunological competence could result from the decrease in HLA-DR counts. Increases in CD62L sensitizes monocytes to the tethering effects of endothelial integrins and might contribute to the atherosclerotic process.

Soluble adhesion molecules in coronary surgery and cardiopulmonary bypass with pump prime aprotinin

OBJECTIVE

The purpose of the present study was to establish whether pump prime aprotinin could influence soluble adhesion molecules in patients undergoing elective coronary artery bypass surgery.

DESIGN

Thirty patients admitted for first-time elective coronary artery bypass surgery were randomized into control or aprotinin groups. Patients in the aprotinin group received 280 mg of aprotinin in the pump prime. Plasma levels of soluble adhesion molecules were analyzed perioperatively.

RESULTS

There were no significant changes in plasma sE-selectin after the operation in either group. Plasma sP-selectin increased significantly up to 20 h after reperfusion to the myocardium. Plasma sICAM-1 decreased in the early stage after cardiopulmonary bypass (CPB), then recovered at 4 h after reperfusion and a significant increase in sICAM-1 was observed 20 h later. There were no significant differences between the groups in postoperative changes in sP-selectin (p = 0.21) and sICAM-1 (p = 0.91).

CONCLUSION

Pump prime aprotinin did not influence plasma levels of E-selectin, P-selectin and ICAM-1 in the present patients. The present results do not support the concept of an anti-inflammatory effect of pump prime aprotinin.

Modulation of the inflammatory response to cardiopulmonary bypass by dopexamine and epidural anesthesia

BACKGROUND

Cardiopulmonary bypass (CPB) induces a systemic inflammatory reaction. Microcirculation-dependent alteration of the gut mucosal barrier with subsequent translocation of endotoxins is a postulated mechanism for this inflammatory response. This study was designed to elucidate whether two different approaches to modulate splanchnic perfusion may influence systemic inflammation to CPB.

METHODS

We examined 40 patients scheduled for elective coronary bypass surgery in a prospective, randomized study. One group (DPX) received dopexamine (1 micro g. kg-1. min-1) continuously after induction of anesthesia until 18 h after CPB. The control group (CON) received equal volumes of NaCl 0.9% in a time-matched fashion. In a third group (EPI) a continuous epidural infusion of bupivacaine 0.25% [(body height (cm) - 100). 10-1=ml.h-1] was administered for the whole study period. Procalcitonin (PCT), tumor necrosis factor (TNF-alpha), soluble TNF receptor, human soluble intercellular adhesion molecule-1, C-reactive protein (CRP) and leukocyte count were measured as parameters of inflammation.

RESULTS

All parameters significantly increased following CPB. Increases of PCT, TNF-alpha and leukocyte count were significantly attenuated in the DPX and EPI groups at different time points. However, neither splanchnic blood flow nor oxygen delivery and consumption were different when compared with the CON-group.

CONCLUSION

These results do suggest that mechanisms other than an improved splanchnic blood flow by DPX and EPI treatment have to be considered for the anti-inflammatory effects.

Inflammation After Cardiopulmonary Bypass: Therapy for the Postpump Syndrome

Cardiopulmonary bypass (CPB) is used in most, but not all, complex heart operations. CPB is associated with a systemic inflammatory response in adults and children. Many materials-dependent (exposure of blood to non- physiologic surfaces and conditions) and materials-in dependent (surgical trauma, ischemia-perfusion to the organs, changes in body temperature, and release of endotoxin) factors during CPB have been implicated in the etiology of this complex response. The mechanisms involved may include complement activation, release of cytokines, leukocyte activation with expression of ad hesion molecules, and production of various vasoactive and immunoactive substances. Postpump inflamma tion may lead to postoperative complications and may result in respiratory failure, renal dysfunction, bleeding disorders, neurologic dysfunction, altered liver func tion, and ultimately multiple organ failure. Significant efforts are being made to decrease the generation and effects of postpump inflammation. Interventions to this end have included avoiding CPB when possible, im proving the biocompatibility of the involved mechani cal devices, and administering medications that main tain cellular integrity. This article provides an overview of the etiology, pathophysiology, and treatment of postpump inflammation. Perhaps with additional in sight into this syndrome, CPB can be made a safer and more efficacious modality of cardiorespiratory support. Copyright© 2001 by W.B. Saunders Company.

Cytokine mediated endothelial activation during and after normothermic cardiopulmonary bypass: heparin-bonded versus non heparin-bonded circuits

Studies evaluating cytokine production under normothermic cardiopulmonary bypass (CPB) are limited. We evaluated cytokine production, levels of thrombomodulin (TM), and soluble endothelium-derived adhesion molecules (ICAM-1) under normothermic CPB with and without heparin-bonded circuits. Nine patients treated with non heparin-bonded circuits (control group), and seven patients treated with heparin-bonded circuits (heparin group) were the subjects. Granulocyte elastase (G-E), and interleukin (IL) -6 and IL-8 were chosen as proinflammatory mediators, and TM and ICAM-1 served as indicators for endothelial damage. Blood samples were obtained before CPB, 30 minutes after initiation of CPB, at the termination of CPB, and 2 and 24 hours after CPB. G-E values in the heparin group were lower than those in the control group after 30 minutes of CPB. A G-E surge occurred at the end of CPB, and IL-6 and IL-8 surges were observed 2 hours after CPB in both groups. TM and ICAM-1 values, which were reduced at the initiation of CPB, returned to initial levels 2 hours after CPB, and exceeded them 24 hours after CPB compared with preCPB levels. Both groups showed similar changes. We conclude that there are no significant differences in serial G-E, IL-6, IL-8, TM, or ICAM-1 levels between the heparin and control groups during or after normothermic CPB for 2 to 3 hours.

Changes in leucocyte counts and soluble intercellular adhesion molecule-1 and E-selectin during cardiopulmonary bypass in children

A consequence of cardiopulmonary bypass (CPB) in young children is postoperative capillary leak and associated pulmonary dysfunction. Neutrophils sequester in the lungs and may contribute to functional endothelial damage. The endothelial adhesion molecules, E-selectin and intercellular adhesion molecule-1 (ICAM-1), mediate sequential steps in adhesion by binding to leucocyte ligands. Circulating forms of these proteins have been identified. We studied changes in the plasma concentrations of soluble E-selectin and soluble ICAM-1 using fixed phase immunoassays, and associated leucocyte counts in 10 paediatric patients undergoing CPB. Concentrations of soluble L-selectin and soluble ICAM-1 consistently fell during CPB from preoperative levels of 89 +/- 17 ng/ml (mean +/- 2SEM) and 218 + 61 ng/ml, respectively, to 39 +/- 7 ng/ml and 84 +/- 24 ng/ml, respectively at the beginning of maximum hypothermia. The haemodilution that occurred during CPB largely explained this fall, but not the more marked decrease in white cell counts that also occurred over this period (6.7 +/- 1.1 to 1.7 +/- 0.5 x 10(9)/l) which may reflect increased leucocyte sequestration. By 24 h postoperatively, levels of both soluble adhesion molecules approached preoperative concentrations, as did lymphocyte counts. In marked contrast, neutrophil counts rose appreciably towards the end of CPB, and continued to rise to a maximum of 10.9 +/- 3.1 x 10(9)/l during the immediate postoperative period and remained at these elevated levels 24 h later. Major consistent changes in circulating leucocyte numbers which occur early in cardiopulmonary bypass may reflect changes in adhesion to the endothelium and consequent sequestration. Alterations in the levels of soluble adhesion proteins may influence these processes.