Extracorporeal Life Support System Research Articles

Bivalirudin anticoagulation for an infant with heparin resistance on ECMO: A case report.

Extracorporeal membrane oxygenation (ECMO) technology in the field of intense care for children in China has developed rapidly, and it has become a key strategy for the rescue treatment of critically ill children and an advanced extracorporeal life support system. Compared with adults and children, neonatal respiratory disease with ECMO support has the best prognosis, with an average survival rate of 74%. Bleeding and thrombotic events during ECMO are common, morbid, and potentially lethal. Therefore, how to balance the coagulation state is the key to ECMO management. A full-term male infant (2h 5min) was hospitalized for respiratory distress and cyanosis. With a history of premature rupture of membranes (>7 hours) and a birth weight of 3000 g, the patient had Apgar scores of 7, 8, and 9 at 1, 5, and 10 minutes, respectively. This infant has the indication of extracorporeal membrane lung support. After full communication, venoarterial-ECMO was performed, and intravenous infusion of heparin was used for anticoagulation management. We encountered an unreliable heparin monitoring in an infant on ECMO, which considered as heparin resistance. Subsequently, we switched the anticoagulant from heparin to bivalirudin and managed by using multiple laboratory tests including activated clotting time (ACT) and activated partial thromboplastin time. The phenomenon of inconsistent monitoring results occurred later. To help the clinic to adjust the anticoagulation dose accurately, we adopted additional tests such as thrombin-antithrombin complex (TAT) and fibrin/fibrinogen degradation products and applied comparison of thrombela stogram (TEG)-ACT with anticoagulated specimens and bedside non-anticoagulated ACT, then recommended clinicians to use activated partial thromboplastin time combined with TAT. In collaboration with other symptomatic supportive treatments, the ECMO flow was gradually reduced, the respiratory and circulatory functions were stable after reducing the flow rate, there was no bleeding tendency, and the ECMO was finally evacuated. Due to the unique physiological characteristics of newborns, the hemostatic changes differ significantly from those in adults. Precise monitoring of anticoagulation becomes a critical and challenging task. Bivalirudin can be effectively used for anticoagulation management in neonatal ECMO; however, due to its unique characteristics, precise dose adjustment poses a challenge. Selecting the optimal laboratory monitoring indicators is crucial in this regard. In some cases, bedside ACT may not be the optimal anticoagulation monitoring parameter, and when necessary, comparative analysis can be conducted using anticoagulant-sample ACTs such as thrombela stogram-ACT. Traditional markers such as D-dimer/fibrinogen degradation products and newer indicators like TAT can reflect the activation of coagulation and assist in monitoring the anticoagulation effect, especially when there is conflicting information among the monitoring parameters.

Different ECLS Pump Configurations for Temporary Right Ventricular Assist Device in LVAD Patients: A Retrospective Case–Control Study

Background: Acute right ventricular failure is a critical complication after left ventricular assist device (LVAD) implantation, often managed with a temporary paracorporeal right ventricular assist device (RVAD). This study examined three extracorporeal life support (ECLS) systems regarding mortality, bleeding complications, and intensive care unit (ICU) stay duration. Methods: This monocentric, retrospective case–control study included all patients receiving LVAD with paracorporeal RVAD between 2009 and 2020. Three patient groups were formed: CentrimagTM (A), CardiohelpTM (B), and DeltastreamTM (C). Results: A total of 245 patients were included. Preoperative parameters were similar between the CentrimagTM and DeltastreamTM groups, but CardiohelpTM patients had worse Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Scores (A: 1.7 ± 0.8, B: 1.36 ± 0.5, C: 1.9 ± 0.9; p < 0.05). In-hospital death rates were A: 61 (41.8%), B: 15 (32.6%), C: 29 (54.7%); p < 0.05, and reoperation due to bleeding rates were A: 32 (21.9%), B: 8 (17.4%), C: 25 (47.2%); p < 0.05, with the DeltastreamTM group showing the highest rates. This group also had increased thrombocyte consumption and prolonged ICU stays. Conclusions: Temporary RVADs lead to bleeding complications, affecting patient outcomes. The DeltastreamTM group had significantly higher bleeding complications, likely due to high pump revolution rates and thrombocyte decline. Due to the study’s retrospective nature and complex patient profiles, these interesting findings should be validated in future studies.

Pushing the Survival Bar Higher: Two Decades of Innovation in Lung Transplantation.

Survival after lung transplantation has significantly improved during the last two decades. The refinement of the already existing extracorporeal life support (ECLS) systems, such as extracorporeal membrane oxygenation (ECMO), and the introduction of new techniques for donor lung optimization, such as ex vivo lung perfusion (EVLP), have allowed the extension of transplant indication to patients with end-stage lung failure after acute respiratory distress syndrome (ARDS) and the expansion of the donor organ pool, due to the better evaluation and optimization of extended-criteria donor (ECD) lungs and of donors after circulatory death (DCD). The close monitoring of anti-HLA donor-specific antibodies (DSAs) has allowed the early recognition of pulmonary antibody-mediated rejection (AMR), which requires a completely different treatment and has a worse prognosis than acute cellular rejection (ACR). As such, the standardization of patient selection and post-transplant management has significantly contributed to this positive trend, especially at high-volume centers. This review focuses on lung transplantation after ARDS, on the role of EVLP in lung donor expansion, on ECMO as a principal cardiopulmonary support system in lung transplantation, and on the diagnosis and therapy of pulmonary AMR.

Ethical aspects in the context of extracorporeal life support systems (ECLS): consensus paper of the DGK, DGTHG and DGAI

Extracorporeal life support systems (ECLS) are life-sustaining measures for severe cardiovascular diseases, serving as bridging treatment either until cardiovascular function is restored or alternative treatment, such as heart transplantation or the implantation of permanent ventricular assist devices is performed. Given the insufficient evidence and frequent urgency of implantation without initial patient consent, the ethical challenges and psychological burden for patients, relatives and the interprofessional intensive care team are significant. As with any treatment, an appropriate therapeutic goal for ECLS treatment based on the indications and patient informed consent is mandatory. In order to integrate the necessary ethical considerations into everyday clinical practice, astructured algorithm for handling ECLS is proposed here, which takes ethical aspects into due account.

Age-Related Quality of Life in Cardiac Surgical Patients with Extracorporeal Life Support.

The rationale of the study was to analyze the impact of age on quality of life (QoL) in patients who had undergone cardiac surgery with consecutive extracorporeal life support (ECLS) treatment. The study population consisted of 200 patients, operated upon between August 2006 and December 2018. The patient cohort was divided into two groups following an arbitrary cutoff age of 70 years. Comparative outcome analysis was calculated utilizing the European Quality of Life-5-Dimensions-5-Level Version (EQ-5D-5L). A total of 113 patients were 70 years or less old (group young), whereas 87 patients were older than 70 years (group old). In 45.7% of cases, the ECLS system was established during cardiogenic shock and external cardiac massage. The overall survival-to-discharge was 31.5% (n = 63), with a significantly better survival in the younger patient group (young = 38.9%; old = 21.8%, p = 0.01). Forty-two patients (66%) responded to the QoL survey after a median follow-up of 4.3 years. Older patients reported more problems with mobility (y = 52%; o = 88%, p = 0.02) and self-care (y = 24%; o = 76%, p = 0.01). However, the patients' self-rated health status utilizing the Visual Analogue Scale revealed no differences (y = 70% [50-80%]; o = 70% [60-80%], p = 0.38). Likewise, the comparison with an age-adjusted German reference population revealed similar QoL indices. There were no statistically significant differences in the EQ-5D-5L index values related to sex, number of comorbidities, and emergency procedures. Despite the limited sample size due to the high mortality rate especially in elderly, the present study suggests that QoL of elderly patients surviving ECLS treatment is almost comparable to younger patients.

A new approach towards extracorporeal gas exchange and first invitro results.

Extracorporeal life support (ECLS) pertains to therapeutic and prophylactic techniques utilized in a wide range of medical applications, with severe pulmonary diseases being the most prominent cases. Over the past decades, little progress has been made in advancing the basic principles and properties of gas exchangers. Here, in an unconventional approach, dialysis hollow fibers are handled with silicone to create a purely diffusive coating that prevents plasma leakage and promotes gas exchange. Commercial dialyzers of varying surface area and fiber diameter have been coated with silicone, to determine the impact of each parameter on performance. The impermeability of the silicone layer has been validated by pressurization and imaging methods. SEM images have revealed a homogeneous silicone film coating the lumen of the capillaries, while fluid dynamic investigations have confirmed its purely diffusive nature. The hemodynamic behavior and the gas exchange efficiency of the silicone-coated prototypes have been investigated invitro with porcine blood under various operating conditions. Their performance has been found to be similar to that of a commercial PMP oxygenator. This novel class of gas exchangers is characterized by high versatility and expeditious manufacturing. Intraoperability between conventional ECLS systems and dialysis machines broadens the range of application infinitely. Ultimately, long-term clinical applicability ought to be determined over invivo animal investigations.

Gaseous Nitric Oxide-Cangrelor Combination to Prevent Clots in Extracorporeal Life Support System

IntroductionThe objective of this study was to investigate the potential synergistic utility of a combination of gaseous nitric oxide (gNO)-intravenous Cangrelor as an effective pharmacological option for the prevention of thrombosis in an animal model of extracorporeal life support (ECLS) circuits. Methods10 newborn lambs were placed on ECLS. 5 of them were administered a combination of gNO and intravenous Cangrelor. The remaining 5 were not administered any anticoagulant. The primary end point was duration of ECLS without clot formation. The secondary outcome measure was the absolute maximum transmembrane pressure gradient. ResultsThe mean duration of ECLS were 168 min (standard deviation 224.98 min) in the control group and 402 min (standard deviation 287.5 min) in the experimental group (P = 0.17). The peak trans-oxygenator pressure difference was 43 mm Hg (standard deviation 23 mm Hg) in the control group and 62 mm Hg (standard deviation 71 mm Hg) in the experimental group(P = 0.64). Two animals in the experimental group were supported up to 12 h without clot formation. Clot formation in the experimental group occurred after placement of the cannulae but prior to initiation of ECLS flows after cannulation. ConclusionsA combination of gNO and Cangrelor is prevents clot formation in an experimental animal model when administered through a clean clot-free circuit. However, the combination s ineffective when there are pre-existing clots in the circuit. A bolus of anticoagulation prior to cannulation is needed prior to testing this combination in future studies with a larger sample size.

BIO31: Novel Size-Variable Dedicated Rodent Oxygenator for ECLS Animal Models – Introduction of the “Ratox” Oxygenator and Preliminary In-Vitro Results

Introduction: Extracorporeal life support (ECLS) grows in relevance. However, the survival rate of ECLS remains low, overall at around 60 %, mostly due to hemocompatibility issues. Research and development in the field is slow due to several factors, including the lack of sophisticated experimental platforms and models. This publication introduces a rodent–sized oxygenator module (“RatOx”) to enable early and large–scale in–vitro and in–vivo studies, followed by preliminary in–vitro classification tests on gas transfer performance. The oxygenator is designed to allow extensive in–vitro testing with donated human blood as well as economic and reproducible in–vivo testing for fundamental research. Materials and Methods: The novel RatOx’ main feature is the adaptable fiber module size suitable for various rodents like mice, rats, or hamsters. The effective membrane surface area is variable between approximately 10 cm2 and 600 cm2. The priming volume, and hence the hemodilution of the supported small animal, is kept at a minimum. Any type of semipermeable hollow fiber with any surface modification or coating can be mounted. The housing is transparent, hemocompatible, sterilizable and reusable. Oxygen transfer and carbon dioxide transfer over the oxygenator membrane were tested for different blood flows and fiber module sizes according to DIN EN ISO 7199. Similar experiments were conducted by an independent laboratory to test the transferability of the system to other institutions. Results: At the maximum possible amount of effective fiber surface and a blood flow of 100 ml/min, the oxygenator performance has been tested to a maximum of 5.5 ml O2/min and –5.5 ml CO2/min, respectively. For the same operating point, results from the independent laboratory showed transfer rates of 6.27 ml O2/min and –8.2 ml CO2/min, respectively. The priming volume for this the largest fiber module is 5.4 ml, while the smallest possible configuration with a single fiber mat layer has 1.1 ml of priming volume. Discussion, conclusion and outlook: The novel RatOx ECLS system has been evaluated in–vitro to comply to a high degree with all predefined functionality criteria for rodent–sized animal models. The maximum gas transfer efficacy for full-support-scenarios was measured to be approximately 70–80 % of the intended value pre–defined as the demand of a resting Sprague–Dawley rat. The priming volume translates into an oxygenator–caused hemodilution of approximately 25 %. We intend for the RatOx to become a standard testing platform for scientific studies on ECLS therapy and technology. This presentation includes evidence that this system is variable, yet very robust, allowing cross–lab and cross–model testing.

Novel Size-Variable Dedicated Rodent Oxygenator for ECLS Animal Models—Introduction of the “RatOx” Oxygenator and Preliminary In Vitro Results

The overall survival rate of extracorporeal life support (ECLS) remains at 60%. Research and development has been slow, in part due to the lack of sophisticated experimental models. This publication introduces a dedicated rodent oxygenator (“RatOx”) and presents preliminary in vitro classification tests. The RatOx has an adaptable fiber module size for various rodent models. Gas transfer performances over the fiber module for different blood flows and fiber module sizes were tested according to DIN EN ISO 7199. At the maximum possible amount of effective fiber surface area and a blood flow of 100 mL/min, the oxygenator performance was tested to a maximum of 6.27 mL O2/min and 8.2 mL CO2/min, respectively. The priming volume for the largest fiber module is 5.4 mL, while the smallest possible configuration with a single fiber mat layer has a priming volume of 1.1 mL. The novel RatOx ECLS system has been evaluated in vitro and has demonstrated a high degree of compliance with all pre-defined functional criteria for rodent-sized animal models. We intend for the RatOx to become a standard testing platform for scientific studies on ECLS therapy and technology.

Venoarterial extracorporeal membrane oxygenation in acute myocardial infarction

Venoarterial extracorporeal membrane oxygenation in acute myocardial infarction

Aortic Root Replacement Surgery-A Center Experience with Biological Valve Prostheses.

Outcomes after surgical aortic root replacement using different valved conduits are rarely reported. The present study shows the experience of a single center with the use of the partially biological LABCOR (LC) conduit and the fully biological BioIntegral (BI) conduit. Special attention was paid to preoperative endocarditis. All 266 patients who underwent aortic root replacement by an LC conduit (n = 193) or a BI conduit (n = 73) between 01/01/2014 and 31/12/2020 were studied retrospectively. Dependency on an extracorporeal life support system preoperatively and congenital heart disease were exclusion criteria. For patients with (n = 67) and without (n = 199) preoperative endocarditis subanalyses were made. Patients treated with a BI conduit were more likely to have diabetes mellitus (21.9 vs. 6.7%, p < 0.001), previous cardiac surgery (86.3 vs. 16.6%; p < 0.001), permanent pacemaker (21.9 vs. 2.1%; p < 0.001), and had a higher EuroSCORE II (14.9 vs. 4.1%; p < 0.001). The BI conduit was used more frequently for prosthetic endocarditis (75.3 vs. 3.6%; <0.001), and the LC conduit was used predominantly for ascending aortic aneurysms (80.3 vs. 41.1%; <0.001) and Stanford type A aortic dissections (24.9 vs. 9.6%; p = 0.006). The LC conduit was used more often for elective (61.7 vs. 47.9%; p = 0.043) and emergency (27.5 vs. 15.1%; p = 0-035) surgeries, and the BI conduit for urgent surgeries (37.0 vs. 10.9%; p < 0.001). Conduit sizes did not differ significantly, with a median of 25 mm in each case. Surgical times were longer in the BI group. In the LC group, coronary artery bypass grafting and proximal or total replacement of the aortic arch were combined more frequently, whereas in the BI group, partial replacement of the aortic arch were combined. In the BI group, ICU length of stay and duration of ventilation were longer, and rates of tracheostomy and atrioventricular block, pacemaker dependence, dialysis, and 30-day mortality were higher. Atrial fibrillation occurred more frequently in the LC group. Follow-up time was longer and rates of stroke and cardiac death were less frequent in the LC group. Postoperative echocardiographic findings at follow-up were not significantly different between conduits. Survival of LC patients was better than that of BI patients. In the subanalysis of patients with preoperative endocarditis, significant differences between the used conduits were found with respect to previous cardiac surgery, EuroSCORE II, aortic valve and prosthesis endocarditis, elective operation, duration of operation, and proximal aortic arch replacement. For patients without preoperative endocarditis, significant differences were observed concerning previous cardiac surgery, pacemaker implantation history, duration of procedure, and bypass time. The Kaplan-Meier curves for the subanalyses showed no significant differences between the used conduits. Both biological conduits studied here are equally suitable in principle for complete replacement of the aortic root in all aortic root pathologies. The BI conduit is often used in bail-out situations, especially in severe endocarditis, without being able to show a clinical advantage over the LC conduit in this context.

Patterns of oxygen debt repayment in cardiogenic shock patients sustained with extracorporeal life support: A retrospective study.

Cardiogenic shock is the most frequent kind of shock in cardiac intensive care, and cardiac dysfunction and hypoxia are often seen in critically ill patients. Inadequate organ and tissue perfusion and hypoxia result in anaerobic metabolism with hyperlactatemia and oxygen debt accumulation. However, the role of accumulated oxygen debt in the course of cardiogenic shock and hypoxia has not been clearly described. Here, we first described the existence of several patterns of oxygen debt repayment in cardiogenic shock patients maintained by an extracorporeal life support system. Oxygen debt was computed from the lactate concentration at five time points, covering the first 26 h of ECLS. Patterns representing basic pathophysiological processes were independent of the cause of the primary insult. Groups of patients classified into specific patterns differed in terms of survival rate from 51.5% to only 4.6%. It is very important that the initial group not predetermine the fate of the patient and may change in the course of treatment due to 'between-cluster migration'. We believe that our finding of different patterns of oxygen debt repayment in cardiogenic shock patients may offer new insights for a more rational, goal-directed treatment of highly morbid conditions such as hypoxia and cardiogenic shock.

Inflammation and Oxidative Stress in the Context of Extracorporeal Cardiac and Pulmonary Support.

Extracorporeal circulation (ECC) systems, including cardiopulmonary bypass, and extracorporeal membrane oxygenation have been an irreplaceable part of the cardiothoracic surgeries, and treatment of critically ill patients with respiratory and/or cardiac failure for more than half a century. During the recent decades, the concept of extracorporeal circulation has been extended to isolated machine perfusion of the donor organ including thoracic organs (ex-situ organ perfusion, ESOP) as a method for dynamic, semi-physiologic preservation, and potential improvement of the donor organs. The extracorporeal life support systems (ECLS) have been lifesaving and facilitating complex cardiothoracic surgeries, and the ESOP technology has the potential to increase the number of the transplantable donor organs, and to improve the outcomes of transplantation. However, these artificial circulation systems in general have been associated with activation of the inflammatory and oxidative stress responses in patients and/or in the exposed tissues and organs. The activation of these responses can negatively affect patient outcomes in ECLS, and may as well jeopardize the reliability of the organ viability assessment, and the outcomes of thoracic organ preservation and transplantation in ESOP. Both ECLS and ESOP consist of artificial circuit materials and components, which play a key role in the induction of these responses. However, while ECLS can lead to systemic inflammatory and oxidative stress responses negatively affecting various organs/systems of the body, in ESOP, the absence of the organs that play an important role in oxidant scavenging/antioxidative replenishment of the body, such as liver, may make the perfused organ more susceptible to inflammation and oxidative stress during extracorporeal circulation. In the present manuscript, we will review the activation of the inflammatory and oxidative stress responses during ECLP and ESOP, mechanisms involved, clinical implications, and the interventions for attenuating these responses in ECC.

Use of extracorporeal circulation (ECLS/ECMO) for cardiac and circulatory failure : Short version of the S3 guideline

In Germany, aremarkable increase regarding the usage of extracorporeal membrane oxygenation (ECMO) and extracorporeal life support (ECLS) systems has been observed in recent years with approximately 3000 ECLS/ECMO implantations annually since 2015. Despite the widespread use of ECLS/ECMO, evidence-based recommendations or guidelines are still lacking regarding indications, contraindications, limitations and management of ECMO/ECLS patients. Therefore in 2015, the German Society of Thoracic and Cardiovascular Surgery (GSTCVS) registered the multidisciplinary S3 guideline "Use of extracorporeal circulation (ECLS/ECMO) for cardiac and circulatory failure" to develop evidence-based recommendations for ECMO/ECLS systems according to the requirements of the Association of the Scientific Medical Societies in Germany (AWMF). Although the clinical application of ECMO/ECLS represents the main focus, the presented guideline also addresses structural and economic issues. Experts from 17German, Austrian and Swiss scientific societies and apatients' organization, guided by the GSTCVS, completed the project in February2021. In this report, we present asummary of the methodological concept and tables displaying the recommendations for each chapter of the guideline.

Use of extracorporeal circulation (ECLS/ECMO) for cardiac and circulatory failure : Short version of the S3 guideline

In Germany, aremarkable increase regarding the usage of extracorporeal membrane oxygenation (ECMO) and extracorporeal life support (ECLS) systems has been observed in recent years with approximately 3000 ECLS/ECMO implantations annually since 2015. Despite the widespread use of ECLS/ECMO, evidence-based recommendations or guidelines are still lacking regarding indications, contraindications, limitations and management of ECMO/ECLS patients. Therefore in 2015, the German Society of Thoracic and Cardiovascular Surgery (GSTCVS) registered the multidisciplinary S3 guideline "Use of extracorporeal circulation (ECLS/ECMO) for cardiac and circulatory failure" to develop evidence-based recommendations for ECMO/ECLS systems according to the requirements of the Association of the Scientific Medical Societies in Germany (AWMF). Although the clinical application of ECMO/ECLS represents the main focus, the presented guideline also addresses structural and economic issues. Experts from 17German, Austrian and Swiss scientific societies and apatients' organization, guided by the GSTCVS, completed the project in February2021. In this report, we present asummary of the methodological concept and tables displaying the recommendations for each chapter of the guideline.

Needle penetration test - qualifying examination of 3D printable silicones for vascular models in surgical practice

BackgroundDuring cardiogenic shock blood circulation is minimal in the human body and does not suffice to survive. The extracorporeal life support system (ECLS) acts as a miniature heart-lung-machine that can be temporarily implanted over major vessels e.g. at the groin of the patient to bridge cardiogenic shock. To perform this procedure in an emergency, a proper training model is desirable. Therefore, a 3-dimensional-printable (3D) material must be found that mimics large vessel needle penetration properties. A suitable test bench for material comparison is desirable.MethodsA test setup was built, which simulated the clinically relevant wall tension in specimens. The principle was derived from an existing standardized needle penetration test. After design, the setup was fabricated by means of 3D printing and mounted onto an universal testing machine. For testing the setup, a 3D printable polymer with low Shore A hardness and porcine aorta were used. The evaluation was made by comparing the curves of the penetration force to the standardized test considering the expected differences.Results3D printing proved to be suitable for manufacturing the test setup, which finally was able to mimic wall tension as if under blood pressure and penetration angle. The force displacement diagrams showed the expected curves and allowed a conclusion to the mechanical properties of the materials. Although the materials forces deviated between the porcine aorta and the Agilus30 polymer, the graphs showed similar but still characteristic curves.ConclusionsThe test bench provided the expected results and was able to show the differences between the two materials. To improve the setup, limitations has been discussed and changes can be implemented without complications.

Single arterial access ECMELLA: A new concept and step-by-step procedure

Therapy for cardiogenic shock using temporary mechanical circulatory support has improved significantly in the last decades, providing patients with new technologies for both acute phase stabilization and bridging to long-term therapies. A combination of a venoarterial extracorporeal life support system and the Impella left ventricular assist device (known as the ECMELLA approach) represents an effective therapy for severe cardiogenic shock that achieves high-flow circulatory support with simultaneous left-ventricular unloading. We present the new ECMELLA 2.0 concept, whereby a single arterial access technique is used to treat severe cardiogenic shock. The goal of this technique is to reduce access-related complications and make a bedside staged weaning from mechanical support possible.

Neurological Complications in Patients Requiring Durable VAD Systems after ECLS Support. On Behalf of ECLS- Durable MCS Study Group

Purpose Neurological complications are considered as most frequent complications following left ventricular device device (VAD) implantation. The aim of this multicenter study is to investigate neurological complications in patients requiring durable VADs following extra-corporeal life support (ECLS) implantation. Methods Data of eleven high volume ECLS/VAD centers are collected and evaluated to identify patients who underwent durable mechanical circulatory support system implantation after ECLS systems between January 2010 and July 2018. Preoperative parameters and postoperative outcome are analysed. Data of patients who developed postoperative neurological complication will be analysed and compared. A total of 531 patients meets the inclusion criteria. Patients who were supported with pulsatile pumps, CardioWest TAH and DeBakey VADs will be excluded. The outcome of the remaining 501 patients (mean age 53 ±2 yo, 82% male, average ECLS support duration of 7 ± 7 days and average MELD score of 19 ± 8), who were supported with either HeartWare HVAD, HeartMate II or HeartMate III pumps will be analysed. Endpoints The primary endpoint will be freedom from stroke at 30, 180, and 360 days post implant. Association of stroke events with operative strategies (using heart lung machine vs. ECLS for VAD implantation) will be evaluated. Further, factors predicting stroke events in this patient population are analyzed. We hypothesize that postoperative (after VAD Implantation) stroke complications may be higher in this sick patient population on ECLS compared to traditional VAD candidates.

Dynamics of appearance and decay of gaseous microemboli during in vitro extracorporeal circulation.

Extracorporeal life support (ECLS) patients are at risk for complications caused by gaseous microemboli (GME). GMEs can cause hypoxia, inflammation, coagulation, and end-organ damage. The objective of this in vitro study was to assess dynamics of GME formation during circulation of whole blood or a glycerol blood surrogate. We hypothesized that there is no difference in GME counts and sizes between whole blood and the glycerol blood surrogate and that the membrane lung reduces GME counts over time. A circulation platform was developed using the Cardiohelp ECLS system to run either donor blood or glycerol solution. We conducted 10 repetitions consisting of three phases of ultrasound GME detection using the EDAC™ Quantifier (Luna Innovations, Charlottesville, VA, USA) for each group. Phases were 3-minute recordings at the initiation of 2 L/min flow (Phase 1), post-injection of a GME suspension (Phase 2), and 10 minutes after injection (Phase 3). The number and size of GME pre- and post-ML were recorded separately and binned based on diameter ranges. In Phase 1, GME count in blood was higher than in glycerol. In Phase 2, there was a large increase in GME counts; however, most GME were reduced post-membrane in both groups. In Phase 3, there was a significant decrease in GME counts compared to Phase 2. GME > 100 μm in glycerol decreased post membrane. We demonstrated GME formation and decay dynamics during in vitro circulation in an ECLS system with blood and glycerol. GME counts were higher in blood, likely due to varying rheological properties. There were decreases in GME levels post membrane in both groups after GME injection, with the membrane lung effectively trapping the GME, and additional reduction 10 minutes after GME injection.

Postcardiotomy mechanical support in patients with mitral valve prostheses is associated with poor survival.

To elaborate on early survival in patients with mitral valve replacement requiring temporary extracorporeal life support system (ECLS). We analyzed survival, significant bleeding, wound infection, and ECLS duration in 421 from 14,400 patients with postoperative need for ECLS from January 2008 to December 2017 at our institution. Finally, patients were stratified according to the type of surgery performed: the mitral group (mitral valve replacement) n = 63 and the control group (any cardiac surgery excluding the mitral valve) n = 358. In order to adjust for preoperative patient characteristics, a propensity matching analysis was performed. Differences in in-hospital mortality were analyzed accordingly. In-hospital mortality was significantly higher in the mitral group as compared to the control group before and after adjustment (p < 0.001). Median duration of ECLS was 4 days in both groups. Perioperative bleeding (p < 0.001) and wound infection (p < 0.001) also showed significant worse outcome parameters in the mitral group. The main causes of death in the mitral group were multiorgan failure, n = 48 (76%), stroke, n = 7 (12%), and intracardiac thrombus formation, n = 5 (10%). ECLS is associated with a high in-hospital mortality rate in patients after mitral valve replacement.