Conventional Cardiopulmonary Bypass Circuit Research Articles

Comparable bleeding and inflammation outcomes between heparin-coated and uncoated minimal invasive extracorporeal circuits in isolated coronary artery bypass surgery - A double-blinded randomized control trial.

Minimally invasive extracorporeal circulation has been shown to be non-inferior or even superior to conventional cardiopulmonary bypass circuits in isolated coronary artery bypass grafting, but there is little evidence whether the addition of a heparin-coated circuit can further reduce the inflammatory response and amount of bleeding in these patients. A single-center randomized control trial enrolled 49 adult patients scheduled to undergo isolated coronary artery bypass grafting with minimally invasive extracorporeal circulation (MiECC) between January 2015 and December 2018. Patients were randomized 1:1 to either the heparin-coated circuit group, or the uncoated (control) circuit group. The primary outcome was chest tube output 18h after weaning from MiECC, and secondary outcomes included inflammatory (TNF-α, IL-6, IL-8, IL-10) and complement (C3a, C4d, C5a, sC5b-9) biomarkers, platelet count and function (D2D, TAT, SDC1, PF4), number of transfused blood products, and 30-day survival. Patients were randomized to undergo myocardial revascularization using heparin-coated circuits (n = 25), and to the uncoated MiECC circuit (n = 24), with comparable baseline demographics. No significant difference was observed in chest tube output and for all secondary outcomes. IL-6 and IL-8 were increased from baseline at 18h after weaning (effect size 0.29 and 0.05, respectively) and sC5b-9 was lower (effect size 0.11) in the heparin-coated than in the uncoated MiECC, although not significantly different. Compared with an uncoated MiECC circuit, heparin-coated MiECC circuit was not associated with a reduction in postoperative bleeding, transfusion, inflammation, complement activation, and platelet biomarkers, following isolated coronary artery bypass grafting.

The application of modular multifunctional left heart bypass circuit system integrated with ultrafiltration in thoracoabdominal aortic aneurysm repair.

Open thoracoabdominal aortic aneurysm (TAAA) repair is a complex and challenging operation with a high incidence of serious complications, and high perioperative mortality and morbidity. Left heart bypass (LHB) is a circulatory support system used to perfuse the distal aorta during TAAA operation, and the advantages of LHB include guaranteeing distal perfusion, reducing the use of heparin, and diminishing the risk of bleeding and postoperative neurological deficits. In China, the circuit for TAAA repair is deficient, and far from the perfusion requirements. We designed a modular multifunctional LHB circuit for TAAA repair. The modular circuit consisted of cannulation pipelines, functional consumables connection pipelines, and accessory pipelines. The accessory pipelines make up lines for selective visceral perfusion and kidney perfusion, suckers and rapid infusion. The circuit can be assembled according to surgical requirements. The ultrafilter and heat exchanger are integrated into the circuit to fulfill the basic demands of LHB. The LHB circuit also has pipelines for selective visceral perfusion to the celiac artery and superior mesenteric artery and renal perfusion pipelines. Meanwhile, the reserved pipelines facilitate the quick switch from LHB to conventional cardiopulmonary bypass (CPB). The reserved pipelines reduce the time of reassembling the CPB circuit. Moreover, the rapid infusion was integrated into the LHB circuit, which can rapid infusion when massive hemorrhage during the open procedures such as exposure and reconstruction of the aorta. The ultrafiltration can diminish the consequent hemodilution of hemorrhage and rapid infusion. A hemoperfusion cartridge also can be added to reduce the systemic inflammatory during operation. The circuit can meet the needs of LHB and quickly switch to conventional CPB. No oxygenator was required during LHB, which reduce the use of heparin and reduce the risk of bleeding. The heat exchanger contributes to temperature regulation; ultrafiltration, arterial filter, and rapid-infusion facilitated the blood volume management and are useful to maintain hemodynamic stability. This circuit made the assembly of the LHB circuit more easily, and more efficient, which may contribute to the TAAA repair operation performed in lower volume centers easily. 26 patients who received TAAA repair under the modular multifunctional LHB from January 2018-March 2022 were analyzed, and we achieved acceptable clinical outcomes. The in-hospital mortality and 30-day postoperative mortality were 15.4%, and the postoperative incidences of paraparesis (4%), stroke (4%), and AKI need hemodialysis (12%) were not particularly high, based on the limited patients sample size in short research period duration.

The Efficacy of Resin Hemoperfusion Cartridge on Inflammatory Responses during Adult Cardiopulmonary Bypass

Aim: This study aimed to evaluate the efficacy of the resin hemoperfusion device (HA380 hemoperfusion cartridge) on inflammatory responses during adult cardiopulmonary bypass (CPB). Methods: Sixty patients undergoing surgical valve replacement were randomized into the HP group (n = 30) with an HA380 hemoperfusion cartridge in the CPB circuit or the control group (n = 30) with the conventional CPB circuit. The results of routine blood tests, blood biochemical indexes, and inflammatory factors were analyzed at V0 (pre-CPB), V1 (CPB 30 min), V2 (ICU 0 h), V3 (ICU 6 h), and V4 (ICU 24 h). Results: The HP group had significantly lower levels of IL-6, IL-8, and IL-10. Significant estimation of group differences in the generalized estimating equation (GEE) models was also observed in IL-6 and IL-10. The HP group had significantly lower levels of creatinine (Cr), aminotransferase (AST), and total bilirubin (TBil) compared to the control group. The estimation of differences of Cr, AST, and TBil all reached statistical significance in GEE results. The HP group had significantly less vasopressor requirement and shorter mechanical ventilation time and ICU stay time as compared to the control group. Conclusion: The HA380 hemoperfusion cartridge could effectively reduce the systemic inflammatory responses and improve postoperative recovery of patients during adult CPB.

Extension of cardiopulmonary bypass outside the operating room as a short-term bridge to recovery "the poor man's ECMO".

This report describes the use of conventional cardiopulmonary bypass (CPB) circuit beyond the operating room to the critical care unit to provide cardiopulmonary support for patients requiring emergent resuscitation as well as short-term support for rest and recovery of the heart. We modified the CPB circuit and created a closed extra corporeal membrane oxygenation (ECMO) circuit using a conventional oxygenator excluding the venous reservoir. We believe that this technique provides a short-term mechanical support and also acts as a bridge to recovery, or a bridge to decision, in very limited resource settings.

OC06 BUILDING UP A MULTIDISCIPLINARY 360° MINIMALLY INVASIVE PROGRAM FOR AVR: OUR EXPERIENCE

Aim: The aim of this study was to report the first results of our multidisciplinary minimally invasive program to treat patients who require aortic valve replacement (AVR), which involves: 1) reduced chest incision (through upper ministernotomy or right anterior minithoracotomy), 2) sutureless or rapid deployment AVR, 3) minimally invasive extracorporeal circulation (MiECC) system and 4) ultra fast-track (UFT) anaesthesia. Methods: Data from 167 consecutive patients undergoing primary isolated aortic valve replacement through minimally invasive approaches (MIAVR) between October 2016 and April 2018 were prospectively collected. The mean age of the study population was 74 ± 9 years, and the average EuroSCORE II was 2.1 ± 1.2. Results: MIAVR was performed using sutureless or rapid deployment valves in 76 (45.5%) patients, MiECC system in 63 (37.7%), and UFT management in 67 (40.1%). Overall in-hospital mortality was 0.6% (n = 1). The rate of postoperative stroke and atrioventricular block requiring pacemaker implantation was 1.2% (n = 2) and 3.6% (n = 6), respectively. MiECC system was associated with reduced postoperative bleeding (requiring chest re-opening) compared with conventional cardio-pulmonary bypass circuits (0% vs. 5.8%, p = 0.05). The mean intensive care unit stay was 25 hours in UFT patients and 52.2 hours in no-UFT patients (p = 0.04). Hospital stay was similar between groups (UFT 6.9 days, no-UFT 13.9 days, p = 0.2). Conclusions: Our UFT mini AVR program is a multidisciplinary minimally approach that involves the latest best technologies and techniques for AVR. We believe it may considerably increase patient's comfort being associated with faster recovery and excellent hospital outcomes.

Leukocyte filtration of the cardiotomy suction. Does it affect systemic leukocyte activation or pulmonary function?

Cardiopulmonary bypass is thought to propagate a global systemic response through contact with the non-physiological surfaces of the extracorporeal circuit, leading to the stimulation of leukocytes, their adherence to endothelial cells and the release of cytotoxic molecules. This, in turn, has been shown to accelerate pulmonary injury. This study tested a new leukocyte-filtration system (RemoweLL) against a conventional system with no leukocyte-depleting capacity to determine the efficacy of the filtration system and its effects on pulmonary function. Thirty patients underwent coronary artery bypass graft surgery using either the RemoweLL filtration system (15 patients) or a conventional cardiopulmonary bypass circuit (15 patients). Data were collected on the total number of leukocytes, their differentiation and activation, using the leukocyte adhesion integrin CD11b as a surrogate marker. Pulmonary function was assessed using the Alveolar-arterial Oxygenation Index (AaOI) and patients were categorized using the Berlin definition of acute respiratory distress syndrome (ARDS). Both groups showed significant increases in leukocyte numbers during CPB (p<0.001), with no differences noted between the groups. CD11b showed a significant increase in both groups, with peak activation occurring at the end of CPB, but no difference between the groups (p=0.8). There was a trend towards lower AaOI increases in the filtration group, but this did not reach significance (p=0.075) and there was no difference in ARDS definitions (p=0.33). Leukocyte filtration of cardiotomy suction did not influence total leukocyte counts or activation as measured by CD11b upregulation. Furthermore, no evidence could be found to suggest improved pulmonary function.

Do lipid microemboli induce acute kidney injury during cardiopulmonary bypass?

Acute kidney injury (AKI) following cardiopulmonary bypass affects 5% of patients, representing significant postoperative morbidity and mortality. Animal models have shown an increased uptake of lipid microemboli (LME) into the renal vasculature, potentially indicating ischaemic causation. This study tested a new lipid filtration system (RemoweLL) against a conventional system with no lipid-depleting capacity to determine the efficacy of the filtration system and its effects on renal function. Thirty consecutive patients underwent coronary artery bypass graft surgery using either the RemoweLL filtration system (15 patients) or a conventional cardiopulmonary bypass circuit (15 patients). Renal function was assessed using cystatin C concentrations as a surrogate marker of glomerular injury, as well as perioperative glomerular filtration rate (GFR) and serum creatinine concentrations. Patients were defined as having acute renal injury if there was an increase in absolute serum creatinine ⩾3 mg/dL (26.4 µmol/L) or 1.5-fold increase from baseline as categorised using the AKIN criteria. Postoperative differences in LME count between the two groups were highly significant [p<0.001]. Analysis of peak cystatin C concentrations showed significantly lower levels in the LME filtration group on the 2nd postoperative morning [p=0.04]. Two-factor ANOVA revealed a trend towards interaction, but this failed to reach significance [p=0.06]. There were no differences throughout the study period in serum creatinine or GFR [p>0.05]. There were no differences in any of the serum or urinary electrolytes. This study has shown a trend towards improved cystatin C removal with LME filtration; with significantly lower peak concentrations, although no further evidence of renoprotection could be demonstrated. Further research is warranted to establish possible renal benefits of LME filtration in patients undergoing cardiac surgery.

Minimal invasive Extra-Corporeal Circulation (MiECC): a revolutionary evolution in perfusion.

Since the beginning of extracorporeal circulation (ECC) in cardiac surgery, a multitude of changes and improvements were aimed to reduce the adverse systemic effects caused by the artificial surfaces of the perfusion circuit. The clinical picture is similar to a systemic inflammatory response syndrome [1]. The magnitude of the inflammatory response adversely influences clinical outcomes [2]. Hence, the overall morbidity associated with cardiac surgery is substantial [3]. The off-pump coronary artery bypass (OPCAB) technique was introduced as a strategy to decrease the side effects of cardiopulmonary bypass (CPB). But the real advantages of OPCAB have been questioned in recent years [4]. In the early 2000s, a simplified perfusion system comprising all technological advancements was designed [5]. The modifications of the new system were much more revolutionary than the individual improvements to the existing conventional CPB circuits. The idea was to create a system including all established benefits in one CPB set-up. The Minimal Extra-Corporeal Circulation (MiECC) technology was born. Since then, MiECC systems have been developed to increase the technical ease of on-pump surgery while tempering its disadvantages. For many years, cardiac surgeons, anaesthesiologists and perfusionists considered MiECC systems as a miniaturization or simplification of traditional CPB only. MiECC significantly attenuated morbidity attributed to conventional ECC, as for beatingheart procedures, while permitting optimal technical surgical conditions [6]. ‘The authors believe that MiECC technology represents more than a miniaturization process: it is a major step forward and a totally new philosophy to be integrated in contemporary cardiac surgery’. The idea of MiECC systems has initiated new efforts to improve the biocompatibility of CPB systems and minimize their side effects, offering finally better postoperative end-organ function. Characteristics of MiECC include the following: (1) a blood pump with optimal biocompatibility, low thrombogenicity, minimal haemolysis and activation of leucocytes as well as proinflammtory mediators; (2) a minimal tubing length to reduce the priming volume required and thus minimize haemodilution, decreasing the need for foreign blood transfusions; (3) coated surfaces to reduce protein adsorption and platelet activation; (4) separation of shed blood and exclusion of activated blood components via cell salvage; (5) closed system to avoid blood–air contact; (6) temperature management depending on the need and magnitude of surgery should be possible; (7) use of modern concepts of myocardial protection, like blood cardioplegia, must be easy to integrate; (8) safe de-airing must be possible following open heart procedures; (9) finally, it should help modern concepts of fast-track anaesthesia [7, 8]. These characteristics will help to make MiECC an element of a minimal invasive procedure rather than simply a miniaturized CPB system. Numerous randomized clinical studies have proved that MiECC exerts significant beneficial effects on postoperative morbidity, by reducing haemodilution, mediastinal bleeding, need for blood transfusion and inflammatory response. Clinical benefits are: improved end-organ (myocardial, renal and cerebral) protection and reduction of the length of intensive care unit stay [5–8]. Moreover, it is associated with a significant survival benefit in coronary procedures compared with conventional ECC as shown in a recent meta-analysis. This analysis reported randomized trials including 24 studies with a total of 2770 patients [9] and provided a Scientific Class I, Level of evidence A for implementation of MiECC, at least for coronary revascularization. Despite these clear clinical advantages, penetration of the MiECC technology into clinical practice remains significantly low. Thus, the authors took the initiative to organize the ‘1st International Symposium on Minimal invasive Extracorporeal Circulation Technologies (1st MiECT)’ in Thessaloniki, Greece during June 13–14 to create a dedicated international forum to stimulate the exchange of ideas in clinical application and research in the field of Minimal invasive Extracorporeal Circulation Technology without geographical bias (www.miect.org). More than 400 participants from all continents registered. Beside scientific sessions, wet-labs with two simulators for ‘hands-on training’ allowed participants to practice on all commercially available MiECC systems. Twenty abstracts were selected for publication and are part of this Interactive Cardiovascular and Thoracic Surgery issue. During the congress, the ‘Minimal invasive Feedback from the 1st International Symposium on Minimal invasive Extracorporeal Circulation Technologies, Thessaloniki, Greece, 13–14 June 2014.

Comparison of low molecular weight hydroxyethyl starch and human albumin as priming solutions in children undergoing cardiac surgery

Human albumin is the conventional cardiopulmonary bypass circuit primer. However, it has high manufacturing costs. Crystalloid and colloid solutions have been developed as alternatives, including a new generation of non-ionic hydroxyethyl starch (HES). The efficacy of hydroxyethyl starch with a 130 molecular weight and substitution degree of 0.4 (hydroxyethyl starch 130/0.4) was compared with human albumin for use in cardiopulmonary bypass surgery in American Society of Anesthesiologists' grade I-II pediatric congenital heart disease patients. Efficacy was evaluated by comparing perioperative hemodynamic parameters, including plasma colloid osmotic pressure, renal function, blood loss, allogeneic blood volumes and plasma volume substitution. The hydroxyethyl starch group exhibited significantly higher preoperative colloid osmotic pressure (p<0.01) and significantly lower operative renal function and postoperative allogeneic blood volumes than the human albumin group. No significant differences were observed in serum creatinine, glucose, hematocrit or lactic acid levels (p>0.05). Our results indicate that hydroxyethyl starch may be a viable alternative to human albumin in pediatric patients undergoing relatively simple cardiopulmonary bypass surgeries.

Shear Stress, Energy Losses, and Costs: A Resolved Dilemma of Pulsatile Cardiac Assist Devices

Cardiac assist devices (CAD) cause endothelial dysfunction with considerable morbidity. Employment of pulsatile CAD remains controversial due to inadequate perfusion curves and costs. Alternatively, we are proposing a new concept of pulsatile CAD based on a fundamental revision of the entire circulatory system in correspondence with the physiopathology and law of physics. It concerns a double lumen disposable tube device that could be adapted to conventional cardiopulmonary bypass (CPB) and/or CAD, for inducing a homogenous, downstream pulsatile perfusion mode with lower energy losses. In this study, the device's prototypes were tested in a simulated conventional pediatric CPB circuit for energy losses and as a left ventricular assist device (LVAD) in ischemic piglets model for endothelial shear stress (ESS) evaluations. In conclusion and according to the study results the pulsatile tube was successfully capable of transforming a conventional CPB and/or CAD steady flow into a pulsatile perfusion mode, with nearly physiologic pulse pressure and lower energy losses. This represents a cost-effective promising method with low mortality and morbidity, especially in fragile cardiac patients.

NON-INVASIVE IMAGING BASED EVALUATION OF CARDIAC MECHANICS TO MONITOR MYOCARDIAL PERFORMANCE DURING CARDIOPULMONARY BYPASS

We evaluated the role of imaging derived mechanical parameters to monitor cardiac function after different methods of cardiopulmonary bypass (CPB) in an experimental study. We studied 12 piglets (6-10kg) that were placed on CPB with either a conventional CPB circuit primed with fresh blood and

Abstract P77: Reduced Inflammatory Response with a Novel Cardiopulmonary Bypass Circuit: A Prospective Randomized Evaluation

BACKGROUND: The detrimental effects of inflammation following cardiopulmonary bypass (CPB) result in poor postoperative outcomes in patients undergoing heart surgery. A novel CPB circuit (Admiral, Eurosets, Italy) with its inner surface coated with a proprietary phosphorylcholine coating was hypothesized to elicit a reduced inflammatory response compared to a conventional CPB circuit. METHODS: Patients undergoing isolated aortic valve surgery were enrolled in a prospective study and either assigned to Admiral group (Admiral, n=15) or the conventional CPB group (Dideco, n=15). The Admiral oxygenator reduces priming volumes, decreases membrane surface area and incorporates a cell-saver selectively filtering the blood collected through mediastinal cavity before re-transfusion into the patient. The conventional CPB circuit used was a Dideco D903 Avant with an open cardiotomy reservoir. Clinical data and biochemical parameters were measured postoperatively, during CPB and at 1, 18, 36, 48 and 72 hours, respectively. RESULTS: Preoperative demographics such as age (68.2±10.4 vs. 70.9±10), Euroscore (6.8±2.3 vs. 6.2±1.1) as well as others did not differ between Admiral and Dideco groups, respectively. The CPB time (Admiral=104±30 vs. Dideco=99±17 minutes, p=NS), aortic cross clamp time (Admiral=73.2±17.5 vs. Dideco=73.8±19 minutes, p=NS) and the incidence of perioperative complications were also comparable. There was a significant decrease in the Admiral group with respect to inflammatory response, assessed by means of D-dimer (Admiral=1332.3±953.9 vs. Dideco=2791.9±1740.7, p=0.02), CRP (Admiral=169.1±164.8 vs. Dideco=57.1±39.3, p=0.04), IL-6 (Admiral=11.8±12.5 vs. Dideco=26.5±24.9, p=0.02) and TNF-a (Admiral=29±28.7 vs. Dideco=45.5±23.6, p=0.03). CONCLUSIONS: Although no considerable difference was detected in terms of peri-operative outcomes, the Admiral oxygenator did result in a significant reduction of inflammatory markers in immediately postoperative course primarily due to its enhanced biocompatibility. More powerful studies may yield potentially incremental benefits with Admiral oxygenator in future.

Clinical Gaseous Microemboli Assessment of an Oxygenator with Integral Arterial Filter in the Pediatric Population

The use of an arterial line filter (ALF) within the pediatric cardiopulmonary bypass (CPB) circuit is not a new concept. It has always presented the perfusionist with a circuit component that while valuable, increased prime volume. The purpose of this study was to evaluate the change in prime volume and emboli between a conventional oxygenator with separate ALF and a new generation oxygenator with integral arterial filter (AF). We performed a clinical, non-randomized retrospective evaluation of the Terumo Capiox® RX15 (Terumo Cardiovascular Systems Corporation, Ann Arbor, MI) (n= 10) in conjunction with the Terumo Capiox® AF125X ALF or the Capiox ® AF02 vs. the Terumo Capiox® FX15 oxygenator with integral AF (n= 10). The above circuit components, in combination with the LUNA EDAC® (emboli detection and classification) Quantifier (LUNA Innovations, Blacksburg, VA) were placed at various locations within each patient’s CPB circuit to establish and quantify the presence and volume of gaseous emboli during all phases of cardiopulmonary bypass. The EDAC® system is available/used for all patients undergoing CPB at this institution. When compared to a more conventional CPB circuit, the Capiox® FX15 primes more easily as it does not require a carbon dioxide flush while still providing a 32 μ AF. There was no statistical difference in air handling between the tested oxygenators and their associated circuits. During this review it was determined that use of the Capiox® FX15 simplifies the arterial limb of the pediatric CPB circuit. Removal of the separate ALF led to the removal of several, now unnecessary, arterial connectors and additional tubing (arterial line filter bypass). Removal of these components led to a reduction in prime volume and decreased the hemodilutional effect. The FX15 provided a safe, simplified pediatric CPB circuit and was as effective in gaseous microemboli removal as was the more traditional RX15 with separate ALF during this review.

Can a mini-bypass circuit improve perfusion in cardiac surgery compared to conventional cardiopulmonary bypass?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether the 'mini-bypass technique' can give a reduction in complications after cardiac surgery compared to the conventional cardiopulmonary bypass circuit. Altogether 144 papers were found using the reported search, of which 14 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that 10 out of these 14 studies show reduced hemodilution, 7 show reduced red blood cell transfusion, 2 show reduced fresh frozen plasma use (one showing increased use), and 2 show reduced platelet use. Three studies show reduced postoperative blood loss, but one shows increased blood loss. Three studies show better renal function. Four studies show a better cardiac index and 2 show shorter intensive care unit stay. One study found an increased minute volume and reduced oxygenation for one hour post-mini-bypass. Six studies find significantly reduced inflammatory markers, and 5 measure superior myocardial protection. There are several anecdotal references to a 'learning curve' with this technique but no significant morbidity with complications arising from this were found. Mini-bypass seems to be a promising technique with many documented benefits in studies reporting as many as 1000 patients undergoing this technique.

Comparison of Transfusion Requirements for Conventional and Miniaturized Extracorporeal Circuits

Hemodilution is a well-recognized phenomenon of cardiopulmonary bypass (CPB). The degree of hemodilution has attendant risks. As the degree of hemodilution increases, red blood cell transfusions may be necessary, and the risks of blood transfusions are becoming very well recognized. Blood-conservation programs are being developed worldwide to establish strategies to reduce transfusions. Miniaturized extracorporeal circuits (MECs) are associated with less hemodilution than conventional CPB circuits. The use of MECs can be expected to be associated with fewer red blood cell transfusions. The first 250 patients who underwent coronary artery bypass grafting, aortic valve replacement, or both with the use of a MEC were compared with 200 consecutive patients who had similar comorbidities and types of surgery but underwent their operations on a conventional bypass circuit. These surgeries were completed between April 2004 and September 2005 under the care of the same surgical team. The minimum acceptable hematocrit on bypass was 22%. Intra- and postoperative transfusion rates were measured and compared. For conventional bypass, the intraoperative transfusion rate was 36.5%, whereas the rate for the MEC was 23.3%. The postoperative transfusion rate was 55% for operations performed with conventional bypass and 26% for the MEC. The overall in-hospital transfusion rate for conventional bypass was 63% and 36% for the MEC. The data indicate that use of MECs leads to a lower transfusion rate than in surgeries in which conventional CPB is used.

Successful Use of Bivalirudin as Anticoagulant for ECMO in a Patient With Acute HIT

A patient with myocardial failure after repair of an acute type A aortic dissection had acute heparin-induced thrombocytopenia develop during extracorporeal membrane oxygenation. Heparin was discontinued and the anticoagulant was switched to the direct thrombin inhibitor bivalirudin given with a bolus of 0.5 mg/kg followed by a continuous infusion of 0.5 mg/kg/h. Using this protocol, activated clotting time values ranged from 200 to 220 seconds. After prolonged extracorporeal membrane oxygenation support and recovery of left ventricular function, a right ventricular assist device was implanted during extracorporeal membrane oxygenation support with bivalirudin anticoagulation. For this procedure an additional bolus of 0.25 mg/kg bivalirudin was given, and the infusion rate increased to 1 mg/kg/h to achieve activated clotting time values of 300 to 350 seconds. Surgery was successfully performed with moderate intraoperative and postoperative blood loss and transfusion requirements.

A new cardiopulmonary bypass circuit with reduced foreign surface (CorX™): initial clinical experience and implications for anaesthesia management

A new cardiopulmonary bypass circuit with reduced foreign surface (CorX™): initial clinical experience and implications for anaesthesia management

A simplified technique for short-term postcardiotomy pediatric extracorporeal membrane oxygenation

In the current era, extracorporeal membrane oxygenation (ECMO) is one of the appropriate tools for cardiopulmonary mechanical support after reparative surgery for congenital heart disease. Mechanical support is specially indicated for lesions and procedures in which transient postoperative myocardial dysfunction is expected and there is a reasonable chance of recovery. The usual postcardiotomy ECMO technique involves the replacement of the conventional extracorporeal circuit with a special closed ECMO circuit and oxygenator. We describe a modification of the cardiopulmonary bypass (CPB) circuit to create a closed ECMO circuit for short-term support, by using the standard parts of a conventional CPB circuit.

Beating heart surgery using simplified bypass systems compared with conventional cardiopulmonary bypass circuits: Effects on global hemodynamics

Objectives: Cardiac surgery using cardiopulmonary bypass (CPB) leads to the activation of inflammatory mediators due to the contact of blood with foreign surfaces and air. This can result in a hyperdynamic circulatory response after CPB similar to a systemic inflammatory response syndrome. In order to minimize extracorporeal volume, foreign surface area and air-to-blood-contact, simplified bypass systems (SBS) have been developed. SBS are closed-loop-circuits consisting of only the blood pump and the oxygenator.

Duroflo II heparin bonding does not attenuate cytokine release or improve pulmonary function

Background. Comparison of the cytokine generation and leukocyte activation properties of Duroflo II heparin bonded bypass circuit (Baxter Healthcare Corp, Compton, UK) and the conventional cardiopulmonary bypass circuit. Attempt to correlate these to pulmonary dysfunction postoperatively. Methods. Forty patients undergoing elective, isolated coronary artery bypass grafting were randomly allocated to have either plain extracorporeal circuits (group C) or heparin bonded extracorporeal circuits (group H). Full systemic heparinization was used in all patients. The inflammatory response was assessed by measuring plasma levels of interleukin-6, interleukin-8, interleukin-10, and polymorphonuclear elastase. Gas exchange was assessed by measuring the Pa o 2/F io 2 ratio. Results. Significant impairment of oxygenation was seen in both groups with the lowest values at the end of the operation before a gradual return to normal during the next 6 hours. There were no differences between the groups in gas exchange or times to extubation. There were significant elevations in all the cytokines, with interleukin-6 levels peaking at 4 hours in group H and 24 hours in group C, before starting to return to normal at 48 hours. The patterns of interleukin-8 and interleukin-10 rise were identical in the two groups. Polymorphonuclear elastase reached a peak at the end of the operation in group H and remained elevated up to 24 hours, whereas levels continued to rise in group C up to 4 hours. There were no significant differences in levels between groups at any time. There were no differences between the groups in blood loss or blood product usage. Conclusions. Cardiopulmonary bypass induces a systemic inflammatory response with release of cytokines and activation of leukocytes. This correlates with the severe deterioration in pulmonary gas exchange from preoperative levels up to 6 hours postoperatively ( p < 0.05). In the presence of systemic heparinization, Duroflo II heparin bonding of the circuits has minor effects on the pattern of evolution of this inflammatory response.