Standard Cardiopulmonary Bypass Research Articles

Use of Corticosteroids on Prophylaxis of New-Onset Atrial Fibrillation after Cardiac Surgery

Abstract Background Most cardiac operations are performed under cardiopulmonary bypass(CPB); however, it is well known that cardiopulmonary bypass often causes systemic inflammatory response syndrome (SIRS). Cardiac tissue inflammation induced by the CPB and surgical trauma has been previously hypothesized to cause POAF. The relationship between inflammation and atrial fibrillation after cardiac surgery is further strengthened by studies that showed that corticosteroid (CS) prophylaxis can reduce the occurrence of atrial fibrillation after cardiac surgery. Aim of the Work to determine the efficacy of corticosteroids in prophylaxis of POAF and shorten length of intensive care unit (ICU) and hospital stay. Patients and Methods This is randomized controlled clinical trial on 84 patients who underwent their first elective cardiac surgery under cardiopulmonary bypass in Ain Shams University Hospitals. Patients were randomized into two equal groups (n = 42 each) as the control group who underwent a standard cardiopulmonary bypass without any additional medication which was performed under the supervision of a specialized elite and experts in their specialization, and the Methylprednisolone (MP) group who was given 1 g of methylprednisolone (divided into 250 mg every 6h once in the ICU), The primary outcome is the overall occurrence of postoperative AF during the first 72 hours after cardiac surgery. Secondary outcomes are the length of hospital stay, and intensive care unit (ICU) stay. Results This study revealed that using corticosteroids effective in reducing the incidence of POAF without increasing the incidence of postoperative complications and adverse effects due to corticosteroids therapy. This study showed decreased risk of developing AF in patients undergoing cardiac surgery. The incidence of POAF was found be significant lower in MP group 16.7% (7 patients developed AF) versus 35.7% in the control group (15 patients developed AF) (p 0.047). Conclusion Use of Corticosteroids is effective in prophylaxis of POAF in patients undergoing elective cardiac surgery in terms of reducing its incidence and decreasing the length of ICU and hospital stay.

Standard vs high cardiopulmonary bypass flow rate – a randomized controlled sub-trial comparing brain injury biomarker release

Standard vs high cardiopulmonary bypass flow rate – a randomized controlled sub-trial comparing brain injury biomarker release

Comparison of minimal invasive extracorporeal circulation versus standard cardiopulmonary bypass systems on coronary artery bypass surgery.

In this study, we shared our experience with the minimal invasive extracorporeal circulation system for coronary artery bypass grafting patients. A total of 163 patients were included in the retrospective study, with 83 patients (63 males, 20 females; mean age: 61.9±8.9 years; range, 35 to 81 years) undergoing coronary artery bypass grafting with minimal invasive extracorporeal circulation and 80 patients (65 males, 15 females; mean age: 60.5±8.8 years; range, 43 to 82 years) undergoing coronary artery bypass grafting with conventional cardiopulmonary bypass between July 2021 and April 2023. Elective coronary bypass performed by same surgical team were included in the study. Mortality, major adverse cardiac and cerebrovascular event, hospital stays and transfusion requirements were evaluated. There were no significant differences in sex distribution, age, comorbidities, and blood values between the two groups. Intraoperatively, the minimal invasive extracorporeal circulation group had a slightly higher number of distal anastomoses and comparable times for aortic cross-clamp and cardiopulmonary bypass. Postoperative outcomes such as tamponade, bleeding, atrial fibrillation, left ventricular ejection fraction improvement or reduction, and postoperative drainage were similar between the two groups. However, the minimal invasive extracorporeal circulation group had fewer transfusions of packed red blood cells and fresh frozen plasma and a shorter length of stay in the intensive care unit. The minimal invasive extracorporeal circulation system effectively preserves blood, works with lower activated clotting time values without additional complications in coronary artery bypass grafting, and could present a better option for patients with anemia or patients with a relatively high risk for high-dose heparinization.

The Role of Postoperative Magnesium Infusion in Minimizing Ventricular Arrhythmia Risk after Cardiopulmonary Bypass

Introduction: Cardiopulmonary bypass increases the incidence of postoperative ventricular arrhythmias in cardiac surgery. Magnesium, which is essential for cardiac function and may prevent arrhythmias, is frequently reduced after cardiac surgery. Aim of the Study: This study aimed to investigate the preventive effects of magnesium infusion in reducing the occurrence of ventricular arrhythmias in individuals who have undergone cardiopulmonary bypass. Methods: This study, done at Bangabandhu Sheikh Mujib Medical University, Dhaka, from July 2020 to June 2022, involved 120 participants in two groups: one received magnesium sulfate following standard cardiopulmonary bypass surgery (Group A), and the other did not (Group B). Both groups were monitored in the ICU with continuous ECG tracking and assessed for ventricular arrhythmias postoperatively on days 0–3. The inclusion criteria comprised adult cardiac patients in preoperative sinus rhythm with normal magnesium levels, excluding those with a history of ventricular arrhythmias or specific medical conditions. Data collected through a questionnaire, interviews, and medical records were analyzed using SPSS version 26. Result: The mean age of the patients in Group A was 53.83±14.54 years and in Group B was 54.50 ± 10.50 years. The mean difference in postoperative Mg++ was statistically significant (p<0.05) in POD 0, POD 1, POD 2, and POD 3. In this study, there were more VA-positive patients in Group B than in Group A; 16.67% had positive ventricular arrhythmia (PVC 8.3%, VT 3.33%, VF 5.00%), while 83.33% were negative VA. Group B had 66.67% negative VA and 33.33% positive VA (PVC 15.00%, VT 10.00%, VF 8.33%). Conclusion: This study identified that the postoperative Mg infusion after cardio pulmonary bypass reduces the incidence of postoperative arrhythmias in cardiac patients. Based on the findings, we recommend using intravenous magnesium as an alternative to prevent ventricular arrhythmias after CPB in cardiac patients.

Temporary Right Ventricular Support Using the Existing Bypass Circuit During LVAD Implantation

BackgroundRight-sided heart failure after left ventricular assist device (LVAD) implantation carries high morbidity. We sought to develop a technique for expedient short-term right ventricular (RV) support with the cardiopulmonary bypass (CPB) circuit already in use during the LVAD implantation procedure. MethodsPatients at high risk for RV failure during LVAD implantation were supported by a modified CPB circuit. A standard CPB circuit was modified to include a series of 4 wye (Y) bridge connections, allowing the ability to exclude the venous reservoir and oxygenator and to flow venous blood or arterialized blood in the same CPB outflow line. ResultsFrom 2019 to 2022 at a single institution, 6 patients were identified as high risk for early RV failure. Preoperative mean clinical values included central venous pressure of 16.3 ± 3.2 mm Hg, pulmonary capillary wedge pressure of 26.7 ± 3.2 mm Hg, tricuspid annular plane systolic excursion of 1.2 ± 0.23 cm, RV stroke work index of 311.7 ± 32.5, and central venous pressure/pulmonary capillary wedge pressure of 0.61 ± 0.10. All 6 patients were successfully weaned from CPB to LVAD support without the need for RV support at the conclusion of the implantation procedure. ConclusionsWe describe a configuration that supports the right ventricle during the critical period after CPB when it is at high risk of failure while the patient is being resuscitated with transfusions and volume. This technique provides flexibility in the management of complex, critically ill patients with RV failure, increasing the possibility of intraoperative RV recovery and successful separation from CPB during LVAD implantation.

Risk of prolonged ischemic time linked to use of cardiopulmonary bypass during implantation for lung transplantation in the United Kingdom

Some degree of ischemia is inevitable in organ transplantation, and for most, if not all organs, there is a relationship between ischemic time and transplant outcome. The contribution of ischemic time to lung injury is unclear, with conflicting recent data. In this study, we investigate the impact of ischemia time on survival after lung transplantationin a large national cohort. We studied the outcomes for 1,565 UK adult lung transplants over a 12-year period, for whom donor, transplant, and recipient data were available from the UK Transplant Registry. We examined the effect of ischemia time (defined as donor cross-clamp to recipient reperfusion) and whether standard cardiopulmonary bypass was used using Cox proportional hazards models, adjusting for other risk factors. The total ischemic time increased from a median under 5hours in 2003 to over 6.2hours in 2013. Our findings show that, when the cardiopulmonary bypass was used, there was an increase in the hazard of death (of 13% [95% CI: 5%-21%] for 1-year patient survival) for each hour of total ischemic time. However, if the cardiopulmonary bypass was not used for implantation, this link disappeared-there was no statistically significant change in mortality with increasing ischemic time. We document that avoidance of bypass may remove ischemic time, within the limits of our observed range of ischemic times, as a risk factor for poor outcomes. Our dataaddto the evidence that bypass may be harmful to the donor lung.

Efficacy of Hemoperfusion Cartridge Procedure on Patients Undergoing Cardiac Valve Replacement Surgery with Cardiopulmonary Bypass

Cardiopulmonary bypass (CPB) induces inflammatory homeostasis dysregulation, closely related to many postoperative adverse effects. Minimizing the systemic inflammatory response to CPB is imperative to improving cardiac surgery safety. This study aimed to retrospectively evaluate the efficacy of the hemoperfusion cartridge, a device recently designed for extracorporeal blood purification to remove cytokines from the blood for patients undergoing cardiac valve replacement surgery using CPB. The hemoperfusion (HP) group consisted of 138 patients, who underwent a hemoperfusion cartridge procedure during CPB. The control group included 149 patients, who received standard CPB management. The evaluated indices included inflammatory cytokines, blood biochemical indices, and postoperative outcome indices. Patients in the HP group had relatively lower interleukin (IL)-6 levels (days one and two post-CPB) and IL-8 (day one post-CPB) compared with the control group. Some relatively decreased biochemical blood indices also were observed in the HP group, including a significantly lower lactic acid level (days one, two, and three post-CPB), platelet counts (days one, two, and three post-CPB), and aspartate aminotransferase (days one and three post-CPB). Regarding the postoperative outcomes, no severe complications occurred in the patients; however, the HP group required less ventilation time than the control group. The hemoperfusion cartridge seems promising in limiting the inflammatory reactions during CPB, with noteworthy potential for application in cardiac surgery.

Abdominal and Peripheral Tissue Oxygen Supply during Selective Lower Body Perfusion for the Surgical Repair of Congenital Heart Disease: A Pilot Study.

Lower body perfusion (LBP) may be a strategy for maintaining organ perfusion during congenital heart disease surgery. It is hypothesized that renal and lower limb oxygen supply during LBP is superior to off-pump surgery and comparable to that of a standard cardiopulmonary bypass (CPB). in this prospective single-center study, patients aged <1 year were recruited if they were scheduled for a correction of aortic arch anomalies using antegrade cerebral perfusion and LBP (group 1), a repair of coarctation during aortic cross-clamping (group 2), or surgery under whole-body CPB (group 3). Renal (prefix "r") and peripheral (prefix "p") oxygen saturation (SO2), hemoglobin amount (Hb), blood velocity (Velo), and blood flow (Flow) were measured noninvasively. A total of 23 patients were included (group 1, n = 9; group 2, n = 5; group 3, n = 9). Compared to the baseline values, rSO2 and pSO2 decreased significantly in group 2 compared to groups 1 and 3. Conversely, rHB significantly increased in group 2 compared to groups 1 and 3, reflecting abdominal venous stasis. Compared to group 3, group 1 showed a significantly lower pFlow during CPB; however, rFlow, pFlow, and pVelo did not differ. according to these observations, LBP results in an improved renal oxygen supply compared to off-pump surgery and may prove to be a promising alternative to conventional CPB.

Pulmonary Endarterectomy in a Patient with Heparin-Induced Thrombocytopenia using Pre-Cardiopulmonary Bypass Plasmapheresis and Immunoglobulin Infusion

We report a peculiar case of a 77 years woman affected by chronic thromboembolic pulmonary hypertension (CTEPH) with surgical indication to pulmonary endarterectomy (PEA) but with the concomitant presence of anti-PF4-heparin autoantibodies. Coagulation disorders are frequently associated in patients with CTEPH and therefore full thrombophilic pattern evaluation is completed as standard preoperative protocol in all our patients. In this case, history of chronic thrombocytopenia induced us to extend preoperative evaluation to the presence of anti-PF4-heparin autoantibodies. Once heparin-induced thrombocytopenia was documented, an alternative approach rather than standard cardiopulmonary bypass with systemic heparinization was mandatory. Due to the characteristics of surgical procedure (i.e., prolonged CPB time, possible risk of intraoperative and postoperative bleeding), we decided to adopt plasmapheresis and immunoglobulin infusion before surgery, thus allowing the standard use of heparin in CPB. The patient underwent a successful PEA without complications. Hemodynamic and clinical results are satisfactory after 3 years of follow-up.

Interprofessional Simulation in Cardiothoracic Surgery Improves Team Confidence

Interest in simulation has grown substantially, as has enthusiasm for team-based approaches to surgical training. In cardiothoracic surgery, the dynamic ability of the entire team is critical to emergent events. We developed innovative, interprofessional simulation events to improve team confidence. Two separate simulations event replicating critical steps and potential crises of cardiopulmonary bypass (CPB) were attended by members of the multidisciplinary cardiothoracic team. Standard CPB equipment, echocardiography, an app to control vital signs, and typical operating room tools for cannulation were all used. Participant started at their typical roles, then rotated into unfamiliar roles for subsequent simulations. Survey and Likert scale self-assessment tools were used to determine outcomes. Statistical analysis compared results. Two separate events were attended by a total of 37 team members (17 facilitators and 20 participants). Participants rotated roles through 12 routine and high-risk scenarios for instituting and separating from CPB. Participant evaluation results were highly favorable, with requests for further similar events. Objectively, the mean score for self-assessment rose significantly comparing the pre- and post-simulation assessments. Despite a small sample size, these differences did reach statistical significance in two categories: iatrogenic dissection (p 0.008), and emergent return to CPB (p 0.016). In our experience, high-fidelity interprofessional simulation promoted team communication and confidence for key scenarios related to institution of and separation from CPB.

Interprofessional Simulation in Cardiothoracic Surgery Improves Team Confidence.

Interest in simulation has grown substantially, as has enthusiasm for team-based approaches to surgical training. In cardiothoracic surgery, the dynamic ability of the entire team is critical to emergent events. We developed innovative, interprofessional simulation events to improve team confidence. Two separate simulations event replicating critical steps and potential crises of cardiopulmonary bypass (CPB) were attended by members of the multidisciplinary cardiothoracic team. Standard CPB equipment, echocardiography, an app to control vital signs, and typical operating room tools for cannulation were all used. Participant started at their typical roles, then rotated into unfamiliar roles for subsequent simulations. Survey and Likert scale self-assessment tools were used to determine outcomes. Statistical analysis compared results. Two separate events were attended by a total of 37 team members (17 facilitators and 20 participants). Participants rotated roles through 12 routine and high-risk scenarios for instituting and separating from CPB. Participant evaluation results were highly favorable, with requests for further similar events. Objectively, the mean score for self-assessment rose significantly comparing the pre- and post-simulation assessments. Despite a small sample size, these differences did reach statistical significance in two categories: iatrogenic dissection (p 0.008), and emergent return to CPB (p 0.016). In our experience, high-fidelity interprofessional simulation promoted team communication and confidence for key scenarios related to institution of and separation from CPB.

Effect of Nitric Oxide via Cardiopulmonary Bypass on Ventilator-Free Days in Young Children Undergoing Congenital Heart Disease Surgery

In children undergoing heart surgery, nitric oxide administered into the gas flow of the cardiopulmonary bypass oxygenator may reduce postoperative low cardiac output syndrome, leading to improved recovery and shorter duration of respiratory support. It remains uncertain whether nitric oxide administered into the cardiopulmonary bypass oxygenator improves ventilator-free days (days alive and free from mechanical ventilation). To determine the effect of nitric oxide applied into the cardiopulmonary bypass oxygenator vs standard care on ventilator-free days in children undergoing surgery for congenital heart disease. Double-blind, multicenter, randomized clinical trial in 6 pediatric cardiac surgical centers in Australia, New Zealand, and the Netherlands. A total of 1371 children younger than 2 years undergoing congenital heart surgery were randomized between July 2017 and April 2021, with 28-day follow-up of the last participant completed on May 24, 2021. Patients were assigned to receive nitric oxide at 20 ppm delivered into the cardiopulmonary bypass oxygenator (n = 679) or standard care cardiopulmonary bypass without nitric oxide (n = 685). The primary end point was the number of ventilator-free days from commencement of bypass until day 28. There were 4 secondary end points including a composite of low cardiac output syndrome, extracorporeal life support, or death; length of stay in the intensive care unit; length of stay in the hospital; and postoperative troponin levels. Among 1371 patients who were randomized (mean [SD] age, 21.2 [23.5] weeks; 587 girls [42.8%]), 1364 (99.5%) completed the trial. The number of ventilator-free days did not differ significantly between the nitric oxide and standard care groups, with a median of 26.6 days (IQR, 24.4 to 27.4) vs 26.4 days (IQR, 24.0 to 27.2), respectively, for an absolute difference of -0.01 days (95% CI, -0.25 to 0.22; P = .92). A total of 22.5% of the nitric oxide group and 20.9% of the standard care group developed low cardiac output syndrome within 48 hours, needed extracorporeal support within 48 hours, or died by day 28, for an adjusted odds ratio of 1.12 (95% CI, 0.85 to 1.47). Other secondary outcomes were not significantly different between the groups. In children younger than 2 years undergoing cardiopulmonary bypass surgery for congenital heart disease, the use of nitric oxide via cardiopulmonary bypass did not significantly affect the number of ventilator-free days. These findings do not support the use of nitric oxide delivered into the cardiopulmonary bypass oxygenator during heart surgery. anzctr.org.au Identifier: ACTRN12617000821392.

Goal-directed perfusion for reducing acute kidney injury in cardiac surgery: A systematic review and meta-analysis.

Acute kidney injury (AKI) is a common complication following cardiopulmonary bypass (CPB) which can affect morbidity and mortality. Goal-directed perfusion (GDP) intended to avoid the nadir oxygen delivery index below the critical value is associated with reduced postoperative AKI. However, current studies suggested that GDP can only decrease the incidence of AKI stage 1 but showed no effects on AKI stages 2-3 and mortality. The objective of the present meta-analysis is to deter the effects of GDP on postoperative AKI in any stage and mortality following cardiac surgery. MEDLINE, Embase, and the Cochrane Library were searched to identify all clinical trials comparing GDP with control (standard care) during cardiopulmonary bypass conducting in adults undergoing cardiac surgery. The primary outcome was postoperative acute kidney injury. Secondary outcomes included postoperative mortality and length of ICU stay. Data synthesis was obtained by using risk ratio with 95% confidence interval by a random-effects model. From 1094 potential studies, 3 trials enrolling 777 patients were included. Meta-analysis suggested the GDP strategy based on DO2i reduced postoperative AKI compared with standard CPB management (RR = 0.52; 95% CI: 0.38-0.70; p < .0001), especially in AKI stage I (RR = 0.47; 95% CI: 0.33-0.66; p < .0001). But the GDP strategy did not reduce the incidence of severe AKI (stages 2-3) and postoperative mortality. The GDP strategy based on DO2i during CPB obviously reduces AKI stage 1 and thus reduces overall AKI incidence. But it shows no effects on severe AKI (stages 2-3) and mortality.

Hemodynamic evaluation of a new pulsatile blood pump during low flow cardiopulmonary bypass support.

The VentriFlo® True Pulse Pump (VentriFlo, Inc, Pelham, NH, USA) is a new pulsatile blood pump intended for use during short-term circulatory support. The purpose of this study was to evaluate the feasibility of the VentriFlo and compare it to a conventional centrifugal pump (ROTAFLOW, Getinge, Gothenberg, Sweden) in acute pig experiments. Pigs (40-45kg) were supported by cardiopulmonary bypass (CPB) with the VentriFlo (n=9) or ROTAFLOW (n=5) for 6h. Both VentriFlo and ROTAFLOW circuits utilized standard CPB components. We evaluated hemodynamics, blood chemistry, gas analysis, plasma hemoglobin, and microcirculation at the groin skin with computer-assisted video microscopy (Optilia, Sollentuna, Sweden). Pigs were successfully supported by CPB for 6h without any pump-related complications in either group. The VentriFlo delivered an average stroke volume of 29.2±4.8ml. VentriFlo delivered significantly higher pulse pressure (29.1±7.2mmHg vs. 4.4±7.0mmHg, p<0.01) as measured in the carotid artery, with mean aortic pressure and pump flow comparable with those in ROTAFLOW. In blood gas analysis, arterial pH was significantly lower after five hours support in the VentriFlo group (7.30±0.07 vs. 7.43±0.03, p=0.001). There was no significant difference in plasma hemoglobin level in both groups after six hours of CPB support. In microcirculatory assessment, VentriFlo tended to keep normal capillary flow, but it was not statistically significant. VentriFlo-supported pigs showed comparable hemodynamic parameters with significantly higher pulse pressure compared to ROTAFLOW without hemolysis.

Interposition Technique for Pulmonary Valve Replacement.

Stented bioprosthesis implant at surgical pulmonary valve replacement (PVR) ideally should be 25 to 27 mm to facilitate future percutaneous PVR. This often requires accommodating 35 to 37 mm diameter sewing ring in the pulmonary position and requires anterior patch augmentation of the right ventricular outflow tract (RVOT). We present a novel "interposition" technique of PVR that allows upsizing the valve without RVOT patch augmentation. Using standard cardiopulmonary bypass, the main pulmonary artery (MPA) is dissected and transected at an appropriate level. The remnants of pulmonary valve leaflets are excised. The valve stent posts are telescoped into distal MPA, the MPA continuity is restored by end-to-end anastomosis of the proximal and distal MPA, with the interposed prosthetic valve sewing ring in the suture line between the two edges of the MPA with the bulk of the sewing ring extravascular. A total of seven patients (tetralogy of Fallot, three; congenital pulmonary stenosis, four; age range: 15-33 years) underwent the procedure. No patient required RVOT patch augmentation, all patients were extubated in the operating room and were fast-tracked to recovery. Our proposed technique of PVR has the following advantages: accommodate larger size valve, eliminates risk of a paravalvar leak, coronary compression, and anterior tilting of the prosthesis. The valve interposition technique avoids the need for RVOT patch, allows implantation of an adequate sized prosthetic valve, maintains native geometry of the pulmonary artery without the risk of tilting of the prosthesis, and eliminates the risk of paravalvular regurgitation and left coronary compression.

Coronary artery bypass surgery without blood transfusion; is it possible?

Coronary artery bypass surgery is the most commonly performed cardiac operation and approximately 40-70% of patients require a blood transfusion despite improvements in cardiac surgical techniques. Some preventive perfusion methods to avoid transfusions are described, such as acute normovolemic hemodilution, retrograde autologous priming, and usage of integrated arterial filter oxygenator. We combined these three techniques (triple combination technique) to evaluate whether it is possible to avoid blood transfusions in adult patients undergoing coronary artery bypass surgery. A total of 300 consecutive patients were included in this randomized controlled trial. 150 patients (Group 1) were operated with triple combination technique, The other 150 patients (Group 2) were operated with standard cardiopulmonary bypass technique. The two groups were compared in terms of peroperative and postoperative blood product use. Ninety-two percent (92%) of the patients (Group 1) undergoing coronary artery bypass surgery did not require any blood transfusion. Only 8% of the patients required erythrocyte suspension or fresh frozen plasma transfusion. In Group 2, 58% of patients required blood transfusions. The difference between two groups was statistically significant (p < 0,05). Triple combination technique is safe and cost-effective in coronary artery bypass surgery. We think that most of the patients could be operated without blood transfusion with this technique.

A randomized controlled trial comparing controlled reoxygenation and standard cardiopulmonary bypass in paediatric cardiac surgery.

OBJECTIVESControlled reoxygenation on starting cardiopulmonary bypass (CPB) rather than hyperoxic CPB may confer clinical advantages during surgery for congenital cyanotic heart disease.METHODSA single-centre, randomized controlled trial was carried out to compare the effectiveness of controlled reoxygenation (normoxia) versus hyperoxic CPB in children with congenital cyanotic heart disease undergoing open-heart surgery (Oxic-2). The co-primary clinical outcomes were duration of inotropic support, intubation time and postoperative intensive care unit (ICU) and hospital stay. Analysis of the primary outcomes included data from a previous trial (Oxic-1) conducted to the same protocol.RESULTSNinety participants were recruited to Oxic-2 and 79 were recruited to the previous Oxic-1 trial. There were no significant differences between the groups for any of the co-primary outcomes: inotrope duration geometric mean ratio (normoxia/hyperoxic) 0.97, 95% confidence interval (CI) (0.69–1.37), P-value = 0.87; intubation time hazard ratio (HR) 1.03, 95% CI (0.74–1.42), P-value = 0.87; postoperative ICU stay HR 1.14 95% CI (0.77–1.67), P-value = 0.52, hospital stay HR 0.90, 95% CI (0.65–1.25), P-value = 0.53. Lower oxygen levels were successfully achieved during the operative period in the normoxic group. Serum creatinine levels were lower in the normoxic group at day 2, but not on days 1, 3–5. Childhood developmental outcomes were similar. In the year following surgery, 85 serious adverse events were reported (51 normoxic group and 34 hyperoxic group).CONCLUSIONSControlled reoxygenation (normoxic) CPB is safe but with no evidence of a clinical advantage over hyperoxic CPB.Clinical trial registration numberCurrent Controlled Trials—ISRCTN81773762.

Challenges in Perioperative Animal Care for Orthotopic Implantation of Tissue-Engineered Pulmonary Valves in the Ovine Model.

Development of valvular substitutes meeting the performance criteria for surgical correction of congenital heart malformations is a major research challenge. The sheep is probably the most widely used animal model in heart valves regenerative medicine. Although the standard cardiopulmonary bypass (CPB) technique and various anesthetic and surgical protocols are reported to be feasible and safe, they are associated with significant morbidity and mortality rates. The premise of this paper is that the surgical technique itself, especially the perioperative animal care and management protocol, is essential for successful outcomes and survival. Ten juvenile and adult female sheep aged 7.8-37.5months and weighing 32.0-58.0kg underwent orthotopic implantation of tissue-engineered pulmonary valve conduits on beating heart under normothermic CPB. The animals were followed-up for 6months before scheduled euthanasia. Based on our observations, we established a guide for perioperative care, follow-up, and treatment containing information regarding the appropriate clinical, biological, and ultrasound examinations and recommendations for feasible and safe anesthetic, surgical, and euthanasia protocols. Specific recommendations were also included for perioperative care of juvenile versus adult sheep. The described surgical technique was feasible, with a low mortality rate and minimal surgical complications. The proposed anesthetic protocol was safe and effective, ensuring both adequate sedation and analgesia as well as rapid recovery from anesthesia without significant complications. The established guide for postoperative care, follow-up and treatment in sheep after open-heart surgery may help other research teams working in the field of heart valves tissue regeneration.

Inflammation and coagulation following minimally invasive extracorporeal circulation technologies.

Minimally invasive extracorporeal perfusion technologies are based on the use of a minimally invasive extracorporeal circulation (MiECC) system. This includes a closed CPB circuit; biologically inert blood contact surfaces; reduced priming volume; a centrifugal pump; a membrane oxygenator; a heat exchanger; a cardioplegia system; a venous bubble trap/venous air removing device; and a shed blood management system. Some of these items, alone or in combination, are able to modify the blood activation usually elicited by cardiopulmonary bypass (CPB). The hemostatic system activation is less activated and lower degrees of thrombin generation and platelet activation have been found in numerous studies. Additionally, the reduced level of hemodilution plays an important role in preserving clot firmness after CPB with MiECC. These biochemical changes are reflected by a blood loss containment, a reduced need for allogeneic blood transfusions, and, in some studies, by a lower thromboembolic complications rate. The activation of the inflammatory cascade is in turn limited by MiECC, both directly (through a blunting of the contact-phase activation) and indirectly (through a limited thrombin generation, platelet activation, and consequent lower release of pro-inflammatory cytokines). The clinical consequences of this are mainly demonstrated by a lower rate of postoperative atrial fibrillation; other inflammation-derived outcomes appear favorably affected by MiECC (lung function, acute kidney injury) but the multi-factorial nature of these complications makes difficult to clearly attribute this pattern to a lower degree of inflammation. Overall, the existing body of evidence is in favor of MiECC with respect to standard CPB.

The effect of SANGUINATE® (PEGylated carboxyhemoglobin bovine) on cardiopulmonary bypass functionality using a bovine whole blood model of normovolemic hemodilution.

Cardiac surgery using cardiopulmonary bypass carries a high risk of bleeding and need for blood transfusion. Blood administration is associated with increased rates of morbidity and mortality. Perioperatively, strategies are often employed to reduce blood transfusions in high-risk patients or in situations where blood transfusion is contraindicated. Normovolemic hemodilution is a blood conservation technique used during cardiac surgery that involves replacement of blood with fluids. SANGUINATE® (PEGylated carboxyhemoglobin bovine) is a novel hemoglobin-based oxygen carrier that can deliver oxygen effectively to tissues in the presence of severe hypoxia. The use of a hemoglobin-based oxygen carrier during hemodilution may augment tissue oxygen delivery and reduce blood transfusion. Six standardized cardiopulmonary bypass runs simulating normovolemic hemodilution using varying proportions of bovine whole blood and SANGUINATE were performed. Pump speed, flow rate, line pressures, hemoglobin concentration, oxygenation, and degree of anticoagulation were assessed at regular intervals. Membrane oxygenators and arterial line filters were inspected for evidence of clotting following each run. Increases in the pressure drop across the membrane oxygenator were detected during runs 5 and 6. Median activated clotting time values were able to be maintained at goal during the runs, and SANGUINATE did not appear to be thrombogenic. Hemoglobin concentration decreased following the addition of SANGUINATE. Oxygenation was maintained during all runs that included SANGUINATE. SANGUINATE does not impact the performance of the cardiopulmonary bypass circuit in a bovine whole blood model. The results support further evaluation of SANGUINATE in the setting of normovolemic hemodilution and cardiopulmonary bypass.