Conventional Cardiopulmonary Bypass System Research Articles

The effect of using the minimized cardio-pulmonary bypass Systems for Coronary Artery Bypass Grafting in diabetic patients

IntroductionMultiple studies have shown a decrease in the inflammatory response with minimized bypass circuits leading to less complications and mortality rate. On the other hand, some other studies showed that there is no difference in post-operative outcomes. So, the aim of this study is to investigate the clinical benefits of using the Minimized cardiopulmonary Bypass system in Coronary Artery Bypass Grafting and its effect on postoperative morbidity and mortality in diabetic patients as one of the high-risk groups that may benefit from these systems.MethodsThis is a retrospective study that included 114 diabetic patients who underwent Coronary artery bypass grafting (67 patients with conventional cardiopulmonary bypass system and 47 with Minimized cardiopulmonary bypass system). The patients’ demographics, intra-operative characteristics and postoperative complications were compared between the two groups.ResultsCoronary artery bypass grafting was done on a beating heart less commonly in the conventional cardiopulmonary bypass group (44.78% vs. 63.83%, p = 0.045). There was no difference between the two groups in blood loss or transfusion requirements. Four patients in the conventional cardiopulmonary bypass group suffered perioperative myocardial infarction while no one had perioperative myocardial infarction in the Minimized cardiopulmonary bypass group. On the other hand, less patients in the conventional group had postoperative Atrial Fibrillation (4.55% vs. 27.5%, p = 0.001). The requirements for Adrenaline and Nor-Adrenaline infusions were more common the conventional group than the Minimized group.ConclusionThe use of conventional cardiopulmonary bypass for Coronary Artery Bypass Grafting in diabetic patients was associated with higher use of postoperative vasogenic and inotropic support. However, that did not translate into higher complications rate or mortality.

Air removal capacity of two different minimal invasive ECC systems: an in vitro comparison.

Minimally invasive extracorporeal circulation systems are developed to decrease the deleterious effects of cardiopulmonary bypass. For instance, prime volume and foreign surface area are decreased in these systems. However, because of the lack of a venous reservoir in minimized systems, air handling properties of these minimally invasive extracorporeal circulation systems may be decreased as compared to conventional cardiopulmonary bypass systems. The aim of this in vitro study is to compare the air handling properties of two complete minimized cardiopulmonary bypass systems of two manufacturers, of which one system is provided with the air purge control. In an in vitro study, two minimally invasive extracorporeal circulation systems, Inspire Min.I manufactured by Sorin Group Italia, Mirandola, Italy (LivaNova, London, United Kingdom) and minimized extracorporeal circulation manufactured by Maquet, Rastatt, Germany (Getinge, Germany), were challenged with two types of air challenges; a bolus air challenge and a gaseous microemboli challenge. The air removal characteristics of the venous bubble traps and of the complete minimally invasive extracorporeal circulation systems were assessed by measuring the gaseous microemboli volume and number downstream of the venous bubble traps in the arterial line with a bubble counter. No significant differences were observed in air reduction between the venous bubble traps of Getinge (venous bubble traps) and LivaNova (Inspire venous bubble traps 8 in conjunction with the air purge control). Similarly, no significant differences were observed in volume and number of gaseous microemboli in the arterial line of both complete minimally invasive extracorporeal circulation systems. However, the gaseous microemboli load of the Inspire Min.I system was marginally lower after both the bolus air and the gaseous microemboli challenges. Both minimally invasive extracorporeal circulation systems assessed in this study, the LivaNova Inspire Min.I and the Getinge minimized extracorporeal circulation, showed comparable air removal properties, after both bolus and gaseous microemboli air challenges. Besides, air purge control automatic air removal system provided with the LivaNova Inspire Min.I. system may enhance patient's safety with the use of a minimally invasive extracorporeal circulation system. We consider both systems equally safe for clinical use.

Versatile minimized system--a step towards safe perfusion.

A growing body of evidence indicates the superiority of minimized cardiopulmonary bypass (CPB) systems compared to conventional systems in terms of inflammatory reactions and transfusion requirements. Evident benefits of minimized CPB systems, however, do not come without consequences. Kinetic-assisted drainage, as used in these circuits, can result in severe fluctuations of venous line pressures and, consequently, fluctuation of the blood flow delivered to the patient. Furthermore, subatmospheric venous line pressures can cause gaseous microemboli. Another limitation is the absence of cardiotomy suction, which can lead to excessive blood loss via a cell saver. The most serious limitation of minimized circuits is that these circuits are very constrained in the case of complications or changing of the surgery plan. We developed a versatile minimized system (VMS) with a priming volume of about 600 ml. A compliance chamber in the venous line decreases peaks of pressure fluctuations. This chamber also acts as a bubble trap. Additionally, the open venous reservoir is connected parallel to the venous line and excluded from the circulation during an uncomplicated CPB. This reservoir can be included in the circulation via a roller pump and be used as a cardiotomy reservoir. The amount and rate of returned blood in the circulation is regulated by a movable level detector. Further, the circuit can easily be converted to an open system with vacuum-assisted venous drainage in the case of unexpected complications. The VMS combines the benefits of minimized circuits with the versatility and safety of a conventional CPB system. Perfusionists familiar with this system can secure an adequate and timely response at expected and unexpected intraoperative complications.

Miniaturized versus conventional cardiopulmonary bypass and acute kidney injury after cardiac surgery.

Acute kidney injury (AKI) is a serious complication after coronary artery bypass grafting (CABG). There are conflicting reports whether a miniaturized cardiopulmonary bypass (MCPB) system is associated with a lower AKI incidence compared with conventional cardiopulmonary bypass (CCPB). It is unknown if AKI risk factors differ between the two groups. We assessed if MCPB decreases AKI after CABG and compared the risk factors between both groups. Sixty-eight Asian patients presenting for elective CABG at a tertiary heart centre were enrolled. They were randomly assigned to MCPB (n=34) or CCPB group (n=34) and followed up in a single-blinded, prospective, randomized, controlled trial. The primary outcome was Acute Kidney Injury Network stage 1 AKI. The AKI incidence was 21.5% and was not significantly different between patients undergoing MCPB versus CCPB (21.9% versus 21.2%, p=0.948). The first CPB haematocrit was independently associated with AKI in the MCPB group (Relative Risk [RR]=0.484, 95% Confidence Interval [CI]=0.268-0.876, p=0.016); post-operative blood loss and inflammation were independently associated with AKI in the CCPB group (RR=1.005, 95%CI=1.003-1.007, p<0.001; RR=1.018, 95%CI=1.010-1.028, p<0.001). The MCPB system is not associated with a lower incidence of AKI in Asian patients undergoing CABG. Risk factors for AKI differed between patients using the MCPB and CCPB systems.

Ventricular assist device implantation in patients on percutaneous extracorporeal life support without switching to conventional cardiopulmonary bypass system

Ventricular assist device (VAD) implantation using cardiopulmonary bypass (CPB) is an established procedure. However, the well-described complications of CPB may exacerbate multiple organ failure and increase blood product transfusions especially in end-stage heart failure patients. We describe our successful experience in six consecutive patients with profound cardiogenic shock, who were provided on an emergency basis with a percutaneous extracorporeal life support (ECLS) system via the peripheral vessels. After stabilization, a VAD was implanted using ECLS without switching to a conventional CPB system to reduce its side effects. We compared the data with those of 11 patients in whom the VAD was placed with the aid of an additional CPB system. The six patients demonstrated a shorter duration of operating room time compared with the patients requiring CPB for device placement. During and after surgery, blood loss and blood product transfusions were lower in these patients. The need for mechanical ventilation and inotropic support was shorter and the survival rate (100% at 30 days, 83.3% at 3 months and 83.3% at 6 months) was higher when compared with patients who were operated upon with CPB. Two patients were successfully bridged to transplantation. One patient died due to cerebral bleeding after 7 weeks. Our experience suggests that VAD implantation using percutaneous ECLS without switching to conventional CPB is a safe alternative in the bridge to bridge concept, especially in high-risk patients with cardiogenic shock who would benefit from the avoidance of the adverse sequels associated with conventional CPB.

The Early Inflammatory Response in a Mini–Cardiopulmonary Bypass System a Prospective Randomized Study

The aim of this study was to compare the early systemic inflammatory response of the Resting Heart System (RHS; Medtronic, Minneapolis, MN USA), a miniaturized cardiopulmonary bypass (CPB) system, with two groups using a standard extracorporeal circulation system during on-pump coronary artery bypass grafting (CABG) surgery. A total of 60 consecutive patients requiring CABG were prospectively randomized to undergo on-pump CABG using conventional CPB without cardiotomy suction (group A), conventional CPB with cardiotomy suction (group B), or the RHS (group C). Blood samples were collected at five time points: immediately before CPB, 30 minutes into CPB, immediately at the end of CPB, 30 minutes post-CPB, and 1 hour post-CPB. Inflammation was analyzed by changes in (a) levels of plasma proteins, including inflammatory cytokines (interleukin-6 [IL-6], IL-10, and tumor necrosis factor-α), chemokines (IL-8, monokine induced by interferon-γ, monocyte chemotactic protein-1, regulated on activation normal T cell expressed and secreted, and interferon-inducible protein-10), and acute phase proteins (C-reactive protein and complement protein 3); (b) biochemical variables (cardiac troponin I, hematocrit, and immunoglobulin G); and (c) cell numbers (leukocytes, neutrophils, and thrombocytes). The RHS showed more delayed secretion of the cytokines tumor necrosis factor-α and IL-10, chemokines monokine induced by interferon-γ (P < 0.001); IL-8, and interferon-inducible protein-10; and complement protein 3 than conventional CPB systems did. Median thrombocyte numbers were higher in the RHS group. Levels of cardiac troponin I, monocyte chemotactic protein-1, and IL-6 were lower in both the RHS and conventional CPB without suction than with suction. Levels of C-reactive protein and regulated on activation normal T cell expressed and secreted, plus leukocyte and neutrophil numbers, were similar in all groups. The Medtronic RHS may induce less systemic inflammation than conventional CPB systems, particularly when cardiotomy suction was used, but it did not result in improved clinical benefit.

Beneficial effects of using a minimal extracorporeal circulation system during coronary artery bypass grafting

In this study, we assessed clinical results by using a minimal extracorporeal circuit (MECC) and compared it to a conventional cardiopulmonary bypass (CPB) system in patients undergoing coronary artery bypass grafting (CABG) procedures. From August to October 2006, forty consecutive patients undergoing isolated CABG procedures were randomly assigned to either a miniaturized closed circuit CPB with the Maquet-Cardiopulmonary MECC system (Group M, n=20) or to a conventional CPB system (Group C, n=20). Clinical outcomes were observed before, during and after the operation. Besides evaluating the perioperative clinical data, serial blood venous samples were obtained after induction, 30 minutes after CPB initiation, 2h, 6h, 12h, and 24h post-CPB. The focus of our study was on myocardial damage (cTnI), neutrophil and platelet counts, activated partial thromboplastin time (aPTT) and free hemoglobin. Both the transfusion of packed red blood cells and fresh frozen plasma were significantly lower in Group M compared to Group C (p<0.05). The levels of cTnI were lower in Group M at 2h, 6h and 12h post-CPB than in Group C (p<0.01). The values of aPTT in Group M recovered to normal levels after surgery, but were prolonged in Group C at early post-CPB and were statistically longer than Group M at 2h, 6h, and 12h post-CPB (p<0.05). The concentrations of free hemoglobin in Group C were higher than in Group M during and post-CPB, and there was a statistical difference at 2h post-CPB (p<0.05). In conclusion, the MECC system is a safe alternative for patients who undertake extracorporeal circulation (ECC) for CABG surgery. Lower transfusion requirements and less damage to red cells may further promote the use of MECC systems, especially in higher risk patients.

Successful use of a percutaneous miniaturized extracorporeal life support system as a bridge and assistance to left ventricular assist device implantation in a patient with severe refractory cardiogenic shock

We present a 51-year-old man with cardiogenic shock in whom a percutaneous extracorporeal life support system (ECLS) was inserted to restore cardiopulmonary stability. After successful stabilization, a left ventricular assist device was implanted, using the ECLS without switching to a conventional cardiopulmonary bypass system to reduce its side effects.

Prospective, Randomized Study Comparing Two Different Minimized versus Conventional Cardiopulmonary Bypass Systems

Conventional cardiopulmonary bypass (CCPB) is a major trigger of inflammatory response. We aimed to assess the impact of two different minimized cardiopulmonary bypass systems (mini-CPB) with and without Bioline-coating compared with CCPB regarding organ function, inflammatory response, and early clinical outcome. In a prospective, randomized study, 120 patients underwent elective coronary artery bypass grafting and were randomized into three groups: mini-CPB using a Bioline-coated (group A, n = 40) or an uncoated (group B, n = 40) circuit, or CCPB (group C, n = 40). Cytokines (interleukin-6, interleukin-8, and tumor necrosis factor-alpha), myocardial markers (creatine kinase [CK], CK-MB, and troponin-T), hematocrit, and platelet counts were measured up to 48 hours postoperatively. Early clinical outcome was assessed at 3 months postoperatively. Demographics, number of distal anastomoses, ventilation time, blood loss, intensive care unit, and hospital stay were comparable (P = not significant). Extracorporeal circulation and cross-clamp time were significantly longer in group A and B versus C (P < 0.005). No significant differences could be found in the release of interleukin-6, interleukin-8, and tumor necrosis factor-alpha among groups. Myocardial markers were significantly reduced in group A and B versus group C (P < 0.001). Hematocrit and platelet counts did not differ among the groups. No differences could be found in early clinical outcome up to 3 months. This study showed significant better myocardial preservation with lower CK-MB and troponin-T levels in both mini-CPB groups. No significant differences could be found in terms of inflammation, hematologic effects, and early clinical outcome.

Prospective, Randomized Study Comparing Two Different Minimized versus Conventional Cardiopulmonary Bypass Systems

Prospective, Randomized Study Comparing Two Different Minimized versus Conventional Cardiopulmonary Bypass Systems

Minimizing Cardiopulmonary Bypass Attenuates Myocardial Damage After Cardiac Surgery

The standard heart-lung machine is deemed a major trigger of systemic inflammatory reactions, potentially inducing organ failure. The strict reduction of blood-artificial surface and blood-air contact might represent meaningful improvements of the extracorporeal technology with respect to organ preservation. In this study, we assessed perioperative myocardial damage by using a novel minimal extracorporeal circuit (MECC) and a conventional cardiopulmonary bypass (CPB) system. Sixty patients scheduled for coronary artery bypass surgery were randomly assigned to either the MECC or the standard CPB system. Myocardial markers were determined by specific immunoassays 6, 12, and 24 hours after CPB initiation. Results were corrected for hemodilution.Demographics, hemodynamics, the number of anastomoses, CPB, and cross-clamp time were comparable between the groups. MECC patients demonstrated significantly lower levels of Troponin T (ng/ml) at 6, 12, and 24 hours (0.07 +/- 0.01 vs. 0.16 +/- 0.04, p < 0.005; 0.12 +/- 0.03 vs. 0.28 +/- 0.08, p < 0.008; 0.21 +/- 0.05 vs. 0.35 +/- 0.09, p < 0.03, respectively) and creatine kinase-MB (U/l) at 6 and 12 hours (22.5 +/- 1.5 vs. 40.6 +/- 3.3, p < 0.0001; 23.3 +/- 3.4 vs. 40.8 +/- 8.0, p < 0.001, respectively). Creatine kinase-MB at 24 hours tended to lower values in the MECC group but did not quite reach statistical significance. The MECC system may not only provide a less invasive solution to meet the requirements during cardiac surgery but also a more organ-preserving alternative to standard CPB.

The use of Minimized Extracorporeal Circulation System has a Beneficial Effect on Hemostasis--A Randomized Clinical Study

Conventional cardiopulmonary bypass (CPB) is associated with increased coagulation and fibrinolytic activity. A closed miniaturized bypass circuit (CorX) features a significantly reduced tubing set, an integrated pump, and an air removal system without a cardiotomy reservoir. In a prospective randomized trial, the effects on hemostasis were investigated while comparing CorX with conventional CPB in patients undergoing coronary artery bypass grafting. Over a period of 1 year, 81 patients were randomly assigned either to the CorX system (n = 39, group A) or standard CPB system (n = 42, group B). Primary endpoints were platelet count, plasmin-antiplasmin complex (PAP), prothrombin fragments 1+2 (F1+F2), D-dimers, and fibrinogen. Secondary end-points were hematocrit, blood loss in the first 12 hours postoperatively, transfused packed red blood cells, and fresh frozen plasma in the first 24 hours postoperatively. In addition, we analyzed partial thromboplastin time, prothrombin time, and antithrombin III. After aortic declamping, PAP complex and prothrombin F1+F2 were significantly lower in group A than in group B. The difference in D-dimers between groups reached significance at 1 hour post-CPB. Hematocrit values at the end of CPB measured 26 +/- 6% in group A versus 22 +/- 4% in group B (P = .01). The rest of the observed parameters did not significantly differ between groups. Postoperative blood loss was not reduced in the present study. However, the use of the CorX system leads to a significant suppression of activation of coagulation and fibrinolytic cascades compared to conventional CPB, suggesting that miniaturized extracorporeal circuits are a step forward toward reduced imbalance of hemostasis in cardiac surgery.

Mini-circuit cardiopulmonary bypass with vacuum assisted venous drainage: feasibility of an asanguineous prime in the neonate.

Conventional cardiopulmonary bypass (CPB) in neonates results in increased transfusion requirements and hemodilution. There has been little advancement in CPB for the neonatal population. There is evidence that increased priming volumes and blood product transfusion enhances inflammatory response to CPB and increases myocardial and pulmonary dysfunction. We have devised a miniaturized CPB circuit that utilizes vacuum-assisted venous drainage (VAVD) in an effort to decrease priming volume and avoid transfusion requirements. The purpose of this study was to evaluate the safety and efficacy of this miniaturized CPB system and determine the feasibility of an asanguineous prime. Ten 1-week-old piglets were randomized to five mini- and five conventional CPB pump circuits. Subjects were supported with CPB at 100 ml/kg/min, cooled to 28 degrees C, exposed to 10 min aortic crossclamp with cardioplegic arrest, rewarmed to 37 degrees C, weaned from bypass, and subjected to modified-ultrafiltration (MUF) for approximately 10 min. This method was chosen to simulate a situation with all the elements of clinical CPB. Blood transfusion trigger was a hematocrit <15 on CPB. Serum samples were obtained pre-CPB, at 15 min of CPB onset, immediately post-CPB completion, and immediately post-MUF. Indices of hemolysis (SGOT, LDH), production of inflammatory mediators (interleukin (IL)-8, tumor necrosis factor-alpha (TNFalpha)), and physiologic parameters of inflammation were measured. The overall blood requirement was significantly less in the mini-circuit compared to conventional CPB (47.0+/-5.8 ml vs 314.2+/-31.6 ml; p < 0.0001). The only significant blood requirement in the mini-circuit was to replace the volume removed for samples. During the study, mean arterial pressure (MAP) (p = 0.004), static pulmonary compliance (p = 0.04), platelets (p = 0.0003), and white blood cells (p = 0.003) significantly decreased across the groups. Lung water content (p = 0.02), TNFalpha levels (p = 0.05), and SGOT (p = 0.009) increased significantly during the study, across the groups. Among all parameters tested, except for blood requirement and hematocrit post-CPB, there were no significant differences between the two circuits. VAVD makes asanguineous prime in neonates feasible. When used in this study to miniaturize a conventional-CPB circuit, VAVD with a reconfigured neonatal CPB console and circuit resulted in no detrimental effects, and allowed for markedly decreased priming volumes and blood transfusion requirements.