Segmentation-based cardiomegaly detection based on semi-supervised estimation of cardiothoracic ratio.

The successful integration of neural networks in a clinical setting is still uncommon despite major successes achieved by artificial intelligence in other domains. This is mainly due to the black box characteristic of most optimized models and the undetermined generalization ability of the trained architectures. The current work tackles both issues in the radiology domain by focusing on developing an effective and interpretable cardiomegaly detection architecture based on segmentation models. The architecture consists of two distinct neural networks performing the segmentation of both cardiac and thoracic areas of a radiograph. The respective segmentation outputs are subsequently used to estimate the cardiothoracic ratio, and the corresponding radiograph is classified as a case of cardiomegaly based on a given threshold. Due to the scarcity of pixel-level labeled chest radiographs, both segmentation models are optimized in a semi-supervised manner. This results in a significant reduction in the costs of manual annotation. The resulting segmentation outputs significantly improve the interpretability of the architecture's final classification results. The generalization ability of the architecture is assessed in a cross-domain setting. The assessment shows the effectiveness of the semi-supervised optimization of the segmentation models and the robustness of the ensuing classification architecture.

Target flow deviations on the cardiopulmonary bypass cause postoperative delirium in cardiothoracic surgery-a retrospective study evaluating temporal fluctuations of perfusion data.

OBJECTIVES: Postoperative delirium (POD) is common, costly and associated with long-term morbidity and increased mortality. We conducted a cohort study to assess the contribution of cardiopulmonary bypass (CPB) to the development of POD by means of algorithm-based data processing. METHODS: A database was compiled from 3 datasets of patients who underwent cardiac surgery between 2014 and 2019: intensive care unit discharge files, CPB protocols and medical quality management records. Following data extraction and structuring using novel algorithms, missing data were imputed. Ten independent imputations were analysed by multiple logistic regression with stepwise deletion of factors to arrive at a minimal adequate model. RESULTS: POD was diagnosed in 456/3163 patients (14.4%). In addition to known demographic risk factors and comorbidities like male sex, age, carotid disease, acute kidney failure and diabetes mellitus, cardiopulmonary parameters like total blood volume at the CPB [adjusted odds ratio (AOR) 1.001; confidence interval (CI) 1.1001-1.002] were independent predictors of POD. Higher values of the minimal blood flow were associated with a lower risk of POD (AOR 0.993; CI 0.988-0.997). Flow rates at least 30% above target did emerge in the minimal adequate model as a potential risk factor, but the confidence interval suggested a lack of statistical significance (AOR 1.819; 95% CI: 0.955-3.463). CONCLUSIONS: CPB data processing proved to be a useful tool for obtaining compact information to better identify the roles of individual operational states. Strict adherence to perfusion limits along with tighter control of blood flow and acid-base balance during CPB may help to further decrease the risk of POD.

Prehabilitation in older patients prior to elective cardiac procedures (PRECOVERY): study protocol of a multicenter randomized controlled trial.

BACKGROUND: Previous studies have demonstrated the efficacy of rehabilitation after a cardiovascular procedure. Especially older and multimorbid patients benefit from rehabilitation after a cardiac procedure. Prehabilitation prior to cardiac procedures may also have positive effects on patients' pre- and postoperative outcomes. Results of a current meta-analysis show that prehabilitation prior to cardiac procedures can improve perioperative outcomes and alleviate adverse effects. Germany currently lacks a structured cardiac prehabilitation program for older patients, which is coordinated across healthcare sectors. METHODS: In a randomized, controlled, two-arm parallel group, assessor-blinded multicenter intervention trial (PRECOVERY), we will randomize 422 patients aged 75 years or older scheduled for an elective cardiac procedure (e.g., coronary artery bypass graft surgery or transcatheter aortic valve replacement). In PRECOVERY, patients randomized to the intervention group participate in a 2-week multimodal prehabilitation intervention conducted in selected cardiac-specific rehabilitation facilities. The multimodal prehabilitation includes seven modules: exercise therapy, occupational therapy, cognitive training, psychosocial intervention, disease-specific education, education with relatives, and nutritional intervention. Participants in the control group receive standard medical care. The co-primary outcomes are quality of life (QoL) and mortality after 12 months. QoL will be measured by the EuroQol 5-dimensional questionnaire (EQ-5D-5L). A health economic evaluation using health insurance data will measure cost-effectiveness. A mixed-methods process evaluation will accompany the randomized, controlled trial to evaluate dose, reach, fidelity and adaptions of the intervention. DISCUSSION: In this study, we investigate whether a tailored prehabilitation program can improve long-term survival, QoL and functional capacity. Additionally, we will analyze whether the intervention is cost-effective. This is the largest cardiac prehabilitation trial targeting the wide implementation of a new form of care for geriatric cardiac patients. TRIAL REGISTRATION: German Clinical Trials Register (DRKS; http://www.drks.de ; DRKS00030526). Registered on 30 January 2023.

Unsupervised domain adaptation for the detection of cardiomegaly in cross-domain chest X-ray images.

In recent years, several deep learning approaches have been successfully applied in the field of medical image analysis. More specifically, different deep neural network architectures have been proposed and assessed for the detection of various pathologies based on chest X-ray images. While the performed assessments have shown very promising results, most of them consist in training and evaluating the performance of the proposed approaches on a single data set. However, the generalization of such models is quite limited in a cross-domain setting, since a significant performance degradation can be observed when these models are evaluated on data sets stemming from different medical centers or recorded under different protocols. The performance degradation is mostly caused by the domain shift between the training set and the evaluation set. To alleviate this problem, different unsupervised domain adaptation approaches are proposed and evaluated in the current work, for the detection of cardiomegaly based on chest X-ray images, in a cross-domain setting. The proposed approaches generate domain invariant feature representations by adapting the parameters of a model optimized on a large set of labeled samples, to a set of unlabeled images stemming from a different data set. The performed evaluation points to the effectiveness of the proposed approaches, since the adapted models outperform optimized models which are directly applied to the evaluation sets without any form of domain adaptation.

Improving adult pulsatile minimal invasive extracorporeal circulation in a mock circulation.

BACKGROUND: Pulsatile extracorporeal circulation (ECC) may improve perfusion of critical organs during cardiac surgery. This study analyzed the influence of the components of a minimal invasive ECC (MiECC) on the transfer of pulsatile energy into the pseudo-patient of a mock circulation. METHODS: An aortic model with human-like geometry and compliance was perfused by a diagonal pump. Surplus hemodynamic energy (SHE) was determined from flow and pressure data. Five adult-size oxygenator models and three sizes of cannulas were compared. Pulsatile pump settings were optimized, and parallel dual-pump configurations were evaluated. RESULTS: Oxygenator models showed up to twofold differences in pressure gradients and influenced SHE at flow rates up to 2.0 L min-1 . Adjustments of frequency, systole duration, and rotational speed gain significantly improved SHE compared with empirical settings, with SHE above 21% of mean arterial pressure at flow rates of 1.0 L min-1 to 1.5 L min-1 and SHE above 5% at 3.5 L min-1 . Small diameter cannula (15 Fr) limited SHE compared with larger cannula (21 Fr and 23 Fr). Two diagonal pumps did not provide higher SHE than a single pump, but permitted additional control over pulse pressure and SHE by varying the total fraction of pulsatile flow and the fraction of flow bypassing the oxygenator. CONCLUSIONS: Proper selection of components and optimizations of pump settings significantly improved pulse pressure and SHE of pulsatile MiECC. Surplus hemodynamic energy depended on flow rate with a maximum at 1.0 L min-1 -1.5 L min-1 . Pulsatile MiECC may specifically assist organ perfusion during phases of low flow.

A novel pulsatile blood pump design for cardiothoracic surgery: Proof-of-concept in a mock circulation.

BACKGROUND: Pulsatile perfusion during extracorporeal circulation is a promising concept to improve perfusion of critical organs. Clinical benefits are limited by the amount of pulsatile energy provided by standard pumps. The present study investigated the properties of a novel positive displacement blood pump in a mock circulation. METHODS: The pump was attached to an aortic model with a human-like geometry and compliance as a pseudo patient. Hemodynamic data were recorded while the pump settings were adjusted systematically. RESULTS: Using a regular oxygenator, maximum flow was 2.6 L/min at a pressure of 27 mm Hg and a frequency (F) of 90 bpm. Pulse pressure (PP; 28.9 mm Hg) and surplus hemodynamic energy (SHE; 26.1% of mean arterial pressure) were highest at F = 40 bpm. Flow and pressure profiles appeared sinusoid. Using a low-resistance membrane ventilator to assess the impact of back pressure, maximum flow was 4.0 L/min at a pressure of 58.6 mm Hg and F = 40 bpm. At F = 40 bpm, PP was 58.7 mm Hg with an SHE of 33.4%. SHE decreased with increasing flow, heart rate, and systolic percentage but surpassed 10% with reasonable settings. CONCLUSIONS: The present prototype achieved sufficient flow and pressure ranges only in the presence of a low-resistance membrane ventilator. It delivered supraphysiologic levels of pulse pressure and SHE. Further modifications are planned to establish this concept for adult pulsatile perfusion.

2021 MiECTiS focused update on the 2016 position paper for the use of minimal invasive extracorporeal circulation in cardiac surgery.

The landmark 2016 Minimal Invasive Extracorporeal Technologies International Society (MiECTiS) position paper promoted the creation of a common language between cardiac surgeons, anesthesiologists and perfusionists which led to the development of a stable framework that paved the way for the advancement of minimal invasive perfusion and related technologies. The current expert consensus document offers an update in areas for which new evidence has emerged. In the light of published literature, modular minimal invasive extracorporeal circulation (MiECC) has been established as a safe and effective perfusion technique that increases biocompatibility and ultimately ensures perfusion safety in all adult cardiac surgical procedures, including re-operations, aortic arch and emergency surgery. Moreover, it was recognized that incorporation of MiECC strategies advances minimal invasive cardiac surgery (MICS) by combining reduced surgical trauma with minimal physiologic derangements. Minimal Invasive Extracorporeal Technologies International Society considers MiECC as a physiologically-based multidisciplinary strategy for performing cardiac surgery that is associated with significant evidence-based clinical benefit that has accrued over the years. Widespread adoption of this technology is thus strongly advocated to obtain additional healthcare benefit while advancing patient care.

Anterior Pathway for Epicardial Left Atrial Appendage Clip Occlusion During Minimally Invasive Atrioventricular Valve Surgery.

The left atrial appendage occlusion (LAAO) by endocardial suture is sometimes inadequate and thrombogenic with uncertain electrical competence. Moreover, epicardial LAAO clip placement through the transverse sinus can be technically challenging during minimally invasive atrioventricular valve surgery. Here, we describe our new endoscopic technique via an anterior access pathway in 5 patients with concomitant atrial fibrillation using an epicardial clip device (AtriClip Pro 1 or AtriClip Pro 2, AtriCure, Mason, OH, USA) for LAAO. The LAAO was successful in all patients without residual perfusion and surgical complications. Epicardial LAAO by clip via the anterior access pathway represents a novel and feasible endoscopic technique for minimally invasive atrioventricular valve surgery.

Effects of colloid-based (hydroxyethylstarch 6% 130/0.42, gelafundin 4%) and crystalloid-based volume regimes in cardiac surgery: a retrospective analysis.

Background: The restriction of hydroxyethylstarch (HES) necessitated changes in volume management in cardiac surgery, increasing the use of gelatin (GELA) and crystalloid (CRYS) mono strategies. Methods: This retrospective study evaluated the effects of changed volume replacement management to a GELA or CRYS mono therapy on mortality, acute kidney injury (AKI), blood loss, and transfusion in cardiac surgery patients with at least one coronary artery bypass grafting (CABG) at a university hospital. Three groups (HES n=938, GELA n=397, CRYS n=205) were derived from 1,540 patients with complete data sets. Data were analyzed by multiple regression models. Results: Patients had similar risk profiles, comorbidities, and preoperative routine diagnostics prior to surgery. No difference was observed in mortality and AKI. HES treated patients showed highest blood loss, followed by GELA while CRYS patients had the lowest (P<0.0001). Patients in the HES group had highest transfusion of packed red blood cells (PRBCs) and platelet concentrates (PCs), followed by GELA, whereas CRYS had the lowest (P<0.0001). Fresh frozen plasma (FFP) transfusion, administration of fibrinogen, and prothrombin complex concentrates (PCCs) were highest in HES group. CRYS showed the shortest time of mechanical ventilation (P<0.0001) and left the intensive care unit (ICU) significantly earlier (P<0.0001). Multivariable regression analysis found that colloid volume significantly predicted hospital mortality and renal replacement therapy (RRT), but not AKI. Conclusions: Administration of crystalloids without any colloid showed no differences in mortality or AKI, but less blood loss and transfusion. Colloids should be considered critically and further studies should investigate effects of GELA in cardiac surgery.

Preservation of Adrenoceptor and Endothelin Receptor Mediated Vasoconstriction and of Endothelium-Dependent Relaxation after Cold Storage of Explanted Blood Vessels for ex vivo Analyses.

INTRODUCTION: Adrenoceptor and endothelin (ET) receptor-mediated vasoconstriction as well as endothelium-dependent vasodilation of human saphenous veins were compared before and after 20 h of cold storage. METHODS: Contractile responses to potassium chloride (KCl), norepinephrine (NE), and ET-1 as well as vasodilator responses to acetylcholine (ACh) were evaluated. RESULTS: Storage in HEPES-supplemented Dulbecco's modified Eagle's medium (HDMEM) diminished KCl induced contractile forces to 71% (p = 0.002) and NE induced contractions to 80% (p = 0.037), in contrast to HEPES-supplemented Krebs-Henseleit solution (HKH) and TiProtec solution. KCl-normalized NE contractions were not affected by storage. NE EC50 values were slightly lower (7.1E-8 vs. 7.5E-8, p = 0.019) after storage in HKH, with no changes after storage in the other solutions. Endothelium-dependent responses to ACh were not affected by storage. ET-1 induced contractions were attenuated after storage in HDMEM (77%, p = 0.002), HKH (75%, p = 0.020), and TiProtec (73%, p = 0.010) with no changes in normalized constrictions. ET-1 EC50 values were not affected by storage. CONCLUSION: Loss of contractility after storage in HDMEM may reflect the lower content of dextrose. There was no specific attenuation of adrenoceptor, ET-receptor, or ACh receptor mediated signal transduction after storage in any of the media. HKH or TiProtec are equally suitable cold storage solutions for ex vivo measurements.

The value of perioperative biomarker release for the assessment of myocardial injury or infarction in cardiac surgery.

OBJECTIVES: Cardiac biomarkers are indicators of irreversible cell damage. Current myocardial infarction (MI) definitions require concomitant clinical characteristics. For perioperative MI, a correlation of biomarker elevations and mortality has been suggested. Definitions emerged relying on cardiac biomarker release only. This approach is questionable as several clinical and experimental scenarios exist where relevant biomarker release can occur apart from MI. METHODS: We reviewed the clinical and basic science literature and revealed important aspects regarding the use and interpretation of cardiac biomarker release with special focus on their interpretation in the perioperative setting. RESULTS: Ischaemic biomarkers may be released without cell death in multiple conditions, such as after endurance runs in athletes, temporary inotropic stimulation in animal models and flow variations in in vitro cell models. In addition, access through atrial tissue during cannulation or concomitant valve procedures adds sources of enzyme release that may not be related to ventricular ischaemia (i.e. MI). Such non-cell death-related mechanisms may explain the lack of poor correlations of enzyme release and long-term outcomes in recent trials. In addition, the 3 main biomarkers, troponin T, I and creatine kinase myocardial band, differ in their release kinetics, which may differentially trigger MI events in trial patients. CONCLUSIONS: The identification of irreversible myocardial injury in cardiac surgery based only on biomarker release is unreliable. Cell death- and non-cell death-related mechanisms create a mix in the perioperative setting that requires additional markers for proper identification of MI. In addition, the 3 most common ischaemic biomarkers display different release kinetics adding to the confusion. We review the topic.

Aging of human hematopoietic stem cells is linked to changes in Cdc42 activity.

In this study, we characterize age-related phenotypes of human hematopoietic stem cells (HSC). We report increased frequencies of HSC, hematopoietic progenitor cells and lineage negative cells in the elderly but a decreased frequency of multi-lymphoid progenitors. Aged human HSC further exhibited a delay in initiating division ex vivo though without changes in their division kinetics. The activity of the small RhoGTPase Cdc42 was elevated in aged human hematopoietic cells and we identified a positive correlation between Cdc42 activity and the frequency of HSC upon aging. The frequency of human HSC polar for polarity proteins was, similar to the mouse, decreased upon aging, while inhibition of Cdc42 activity via the specific pharmacological inhibitor of Cdc42 activity, CASIN, resulted in re-polarization of aged human HSC with respect to Cdc42. Elevated activity of Cdc42 in aged HSC thus contributed to age-related changes in HSC. Xenotransplant, using NBSGW mice as recipients, showed elevated chimerism in recipients of aged compared to young HSC. Aged HSC treated with CASIN ex vivo displayed an engraftment profile similar to recipients of young HSC. Taken together, our work reveals strong evidence for a role of elevated Cdc42 activity in driving aging of human HSC, and similar to mice, this presents a likely possibility for attenuation of aging in human HSC.

Does Preoperative Sinus Rhythm Influence Surgical Ablation's Perioperative Safety in Patients with Atrial Fibrillation?

BACKGROUND: Despite excellent data on lowering long-term stroke and all-cause mortality rates, currently, only 25-40% of atrial fibrillation (AF) patients undergo simultaneous surgical ablation therapy (SA) during cardiac surgery. Surgeon's fear exposing their patients to an additional, unjustified, and disproportionate risk when performing SA in AF patients presenting with sinus rhythm (SR) before surgery. To clarify the influence of preoperative SR before SA for AF, we conducted a subgroup analysis of the German Cardiosurgical Atrial Fibrillation (CASE-AF) register. METHODS: Between September 2016 and August 2020, 964 AF patients with an underlying cardiac disease were scheduled for surgery with SA and enrolled in the CASE-AF register. Data prospectively were collected and analyzed retrospectively. We divided the entire cohort into an SR-group (38.2%, N = 368) and an AF-group (61.8%, N = 596), based on preoperative heart rhythm. RESULTS: Over half of the patients were moderately affected by their AF, with no difference between the groups (European Heart Rhythm Association class ≥IIb: SR-group 54.2% versus AF-group 58.5%, P = .238). The AF-group had a higher preoperative EuroSCORE II (4.8 ± 8.0% versus 4.2 ± 6.3%, P = .014). In-hospital mortality (SR-group 0.8% versus AF-group 1.7%, P = .261), major perioperative adverse cardiac and cerebrovascular events (SR-group 2.7% versus AF-group 3.5%, P = .500), and the new pacemaker implantation rate (SR-group 6.0% versus AF-group 5.9%, P = .939) were low and showed and no group difference. Logistic regression analysis showed a protective effect for preoperative SR to perioperative complications in AF patients undergoing SA (odds ratio (OR) 0.72 (95% CI 0.52 - 0.998); P = .0485). CONCLUSIONS: Concomitant SA in AF patients presenting in SR before cardiac surgery is safe, has a low perioperative risk profile, and should be carried out with almost no exceptions.

Impact of pre-existing comorbidities on outcomes of patients undergoing surgical aortic valve replacement - rationale and design of the international IMPACT registry.

BACKGROUND: Degenerative aortic valve disease accounts for 10-20% of all cardiac surgical procedures. The impact of pre-existing comorbidities on the outcome of patients undergoing surgical aortic valve replacement (SAVR) needs further research. METHODS: The IMPACT registry is a non-interventional, prospective, open-label, multicenter, international registry with a follow-up of 5 years to assess the impact of pre-existing comorbidities of patients undergoing SAVR with the INSPIRIS RESILIA aortic valve on outcomes. IMPACT will be conducted across 25 sites in Austria, Germany, The Netherlands and Switzerland and intends to enroll approximately 500 patients. Patients will be included if they are at least 18 years of age and are scheduled to undergo SAVR with the INSPIRIS RESILIA Aortic Valve with or without concomitant ascending aortic root replacement and/or coronary bypass surgery. The primary objective is to determine all-cause mortality at 1, 3, and 5 years post SAVR. Secondary objectives include cardiac-related and valve-related mortality and structural valve deterioration including hemodynamics and durability, valve performance and further clinical outcomes in the overall study population and in specific patient subgroups characterized by the presence of chronic kidney disease, hypertension, metabolic syndrome and/or chronic inflammation. DISCUSSION: IMPACT is a prospective, multicenter European registry, which will provide much-needed data on the impact of pre-existing comorbidities on patient outcomes and prosthetic valve performance, and in particular the performance of the INSPIRIS RESILIA, in a real-world setting. The findings of this study may help to support and expand appropriate patient selection for treatment with bioprostheses. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04053088 .

Non-invasive determination of pressure recovery by cardiac MRI and echocardiography in patients with severe aortic stenosis: short and long-term outcome prediction.

OBJECTIVE: To assess the influence of pressure recovery (PR)-corrected haemodynamic parameters on outcome in patients with aortic stenosis. METHODS: Aortic stenosis severity parameters were corrected for PR (increase in static pressure due to decreasing dynamic pressure), assessed using transthoracic echocardiography (TTE) or cardiac magnetic resonance imaging (CMR), in patients with aortic stenosis. PR, indexed PR (iPR) and energy loss index (ELI) were determined. Factors that predicted all-cause mortality, and 9-month or 10-year New York Heart Association classification ≥2 were assessed using Cox proportional hazards regression. RESULTS: A total of 25 patients, aged 68 ± 10 years, were included. PR was 17 ± 6 mmHg using CMR, and CMR correlated with TTE measurements. PR correction using CMR data reduced the AS-severity classification in 12-20% of patients, and correction using TTE data reduced the AS-severity classification in 16% of patients. Age (Wald 4.774) was a statistically significant predictor of all-cause mortality; effective orifice area (Wald 3.753) and ELI (Wald 3.772) almost reached significance. CONCLUSIONS: PR determination may result in significant reclassification of aortic stenosis severity and may hold value in predicting all-cause mortality.

Pericardial fluids or Cardiopulmonary Bypass-Is There a Major Culprit for Changes in Coagulation and Inflammation?

BACKGROUND: From the results of a previous study, it remained to be investigated if a perioperative rise of few tested coagulation and inflammation markers is caused by conventional cardiopulmonary bypass (CPB) itself or rather by direct recirculation of pericardial fluids. METHODS: Forty-eight patients operated on with conventional CPB for myocardial revascularization were randomized either for direct recirculation of pericardial suction fluids or for cell saving (CS). RESULTS: Thrombin-antithrombin complexes showed lower values intraoperatively in the CS group (p < 0.0001), and D-dimers tended to remain lower at intensive care unit arrival (p = 0.095). Tests of inflammation markers were less meaningful. CONCLUSION: Direct recirculation of pericardial fluids rather than conventional CPB itself causes major intraoperative changes of some coagulation markers. Pericardial blood loss with direct recirculation should be kept to a minimum to avoid unnecessary activation of coagulation. Inflammation markers need further investigations.

Hemoadsorption treatment with CytoSorb® in patients with extracorporeal life support therapy: A case series.

INTRODUCTION: Extracorporeal life support is an increasingly used technique for respiratory and cardiocirculatory support. Besides primary organ dysfunction, an excessive systemic hyperinflammatory response can be the underlying cause for acute organ failure necessitating extracorporeal life support therapy, or it may be associated with the extracorporeal life support itself. Controlling this overwhelming inflammatory response using CytoSorb® hemoadsorption has been shown to be associated with improved hemodynamics and restored metabolic balance resulting in preserved organ functions. METHODS: In this retrospective case series, we describe 23 patients undergoing extracorporeal life support therapy and CytoSorb hemoadsorption. Cytokine levels were monitored, hemodynamic and metabolic variables were recorded, and outcome measures such as duration of organ support, intensive care unit mortality, and hospital mortality were noted. RESULTS: CytoSorb treatment was associated with a trend toward a reduction in plasma cytokine levels (first treatment median interleukin-6 pre 595 vs post 350 pg/mL (n.s.); second treatment median interleukin-6 317 vs 108 pg/mL, p < 0.05), a reduced vasoplegic response resulting in a reduction in vasopressor requirements (first treatment median norepinephrine pre 0.15 vs post 0.02 µg/kg/min (n.s.); second treatment median norepinephrine 0.1 vs 0.02 µg/kg/min, p < 0.05) as well as rebalancing of deranged metabolic parameters (first treatment median lactate pre-treatment 6 vs post-treatment median lactate 2 mmol/L, p < 0.05). The hemoperfusion treatment was well tolerated and safe, without the occurrence of any CytoSorb device-related adverse events. CONCLUSION: Hemoadsorption may offer a potentially promising therapeutic option for critically ill patients undergoing extracorporeal life support therapy, with cytokine reduction and a consecutively mitigated inflammatory response, decreased vasoplegia, and improved organ function as seen in our patients.

Effects of pulsatile minimal invasive extracorporeal circulation on fibrinolysis and organ protection in adult cardiac surgery-a prospective randomized trial.

BACKGROUND: Minimal invasive extracorporeal circulation (MiECC) reduces the impact of cardiopulmonary bypass during cardiac surgery on inflammation and hemostasis. Pulsatile perfusion may enhance organ perfusion and help to prevent renal and neuronal damage. The present study investigated the impact of pulsatile MiECC in low-risk coronary artery bypass grafting (CABG) patients. METHODS: CABG patients were prospectively randomized for non-pulsatile (np: n=19) and pulsatile (p: n=21) MiECC. Blood and urine samples were collected at several time points until 72 h post-operative and analyzed for biochemical markers of fibrinolytic capacity, renal damage, and neuronal damage. RESULTS: Although intraoperative tissue plasminogen activator (tPA) levels tended to be higher in the p group, none of the fibrinolysis markers including plasminogen activator inhibitor (PAI-1) and the PAI-1/tPA ratio were significantly affected by pulsation. Hemolysis and markers of renal and neuronal damage were comparable between groups. Intraoperative urinary excretion [np: 400 mL (355 to 680) vs. p: 530 mL (360 to 900)] and cumulative 24 h volume intake [np: 7,090 mL (5,492 to 7,544) vs. p: 7,155 mL (6,682 to 8,710)] were increased by pulsation whereas blood losses up to 12 h post-operative [np: 365 mL (270 to 515) vs. p: 310 mL (225 to 470)] and up to 24 h post-operative [np: 760 mL (555 to 870) vs. p: 520 mL (460 to 670)] were attenuated. CONCLUSIONS: The present study did not find evidence for a beneficial effect of pulsation on markers of fibrinolysis, renal damage, and neuronal damage. However, pulsatile perfusion increased intraoperative urinary secretion and reduced post-operative blood losses.

Minimized extracorporeal circulation in non-coronary surgery.

Minimally invasive extracorporeal circulation (MiECC) technology is characterized by improved biocompatibility due to closed-loop design, minimized priming, and markedly reduced artificial surface. Despite well-evidenced clinical advantages in coronary surgery, MiECC penetration in complex open-heart surgery is low. Concerns have been raised by surgeons and perfusionist regarding safety of perfusion in situations when the heart is opened and air is entering the closed system. Moreover, issues of blood and volume management are deemed impractical without having a reservoir. In the evolution of MiECC safety aspects as well as means of air and volume management have been addressed. The integration of active air removal devices, and the possibility of venting and volume buffering made MiECC suitable for valvular or even more complex surgery. However, typical clinical benefits found with MiECC in coronary artery bypass grafting (CABG) surgery, in particular blood sparing effects, were not reproducible. Air handling and blood management remain the main issues of MiECC in non-coronary surgery. With the introduction of modular (type IV) MiECC systems containing a second, accessory circuit for immediate conversion to open cardiopulmonary bypass (CPB), the last obstacles seem to be cleared away. The first reports using this latest development in MiECC technology sound promising. It is now up to the cardiac surgical community to adopt this technology and produce data helping to answer the question whether MiECC is the best perfusion strategy for all comer's cardiac surgery.