Factors Affecting the Discrepancy Between Coagulation Times on Extracorporeal Circulation Using Unfractionated Heparin in Children and Young Adults.

In unfractionated heparin (UFH) monitoring during extracorporeal circulation, the traditional measures of activated clotting time (ACT) or activated partial thromboplastin time (APTT) may diverge, confounding anticoagulant adjustments. We aimed to explore the factors explaining this discrepancy in children and young adults. This retrospective observational study, conducted at an urban regional tertiary hospital, included consecutive pediatric patients who received UFH during extracorporeal circulation (continuous kidney replacement therapy or extracorporeal membrane oxygenation) between April 2017 and March 2021. After patients whose ACT and APTT were not measured simultaneously or who were also taking other anticoagulants were excluded, we analyzed 94 samples from 23 patients. To explain the discrepancy between ACT and APTT, regression equations were created using a generalized linear model (family = gamma, link = logarithmic) with ACT as the response variable. Other explanatory variables included age, platelet count, and antithrombin. Compared to APTT alone as an explanatory variable, the Akaike information criterion and pseudo-coefficient of determination improved from 855 to 625 and from 0.01 to 0.42, respectively, when these explanatory variables were used. In conclusion, we identified several factors that may explain some of the discrepancy between ACT and APTT in the routinely measured tests. Evaluation of these factors may aid in appropriate adjustments in anticoagulation therapy.

[Perfusion Methods and Reconstruction Techniques for Performing Aortic Arch Surgery with Isolated Left Vertebral Artery].

In our institution, when we perform aortic arch surgery with isolated left vertebral artery using an extracorporeal circulation, we select an interposed saphenous vein graft technique. This technique has a relatively short clamping time and allows for selective cerebral perfusion and flexible choice of reconstruction site. Although other techniques, such as an island reconstruction, have been reported, we do not perform it often due to its longer ischemic time of the left vertebral artery. On the other hand, we use a direct reconstruction technique in cases where an extracorporeal circulation is not used. This direct reconstruction technique in cases of isolated left vertebral artery could reduce the time and number of clamping it.

[Clinical value of the implication of extracorporeal carbon dioxide removal in patients with acute respiratory distress syndrome].

Extracorporeal carbon dioxide removal (ECCO2R) is a respiratory support technique based on extra-pulmonary gas exchange, which can effectively remove carbon dioxide generated in-vivo, reducing the requirements of respiratory support from mechanical ventilation. With improvements in extracorporeal life support technologies and increasing clinical experience, ECCO2R has potential value in clinical application with acute respiratory distress syndrome (ARDS). This review article discusses the principles of ECCO2R, its relevant indications for ARDS, clinical evidence, existing issues, and future directions, aiming to provide more references for the application in ARDS.

Develop of endocavitary suction device for MiECC on minimally invasive mitral valve surgery.

The minimally invasive extracorporeal circulation (MiECC) system was developed to minimize the contact of blood with air and foreign surfaces during conventional cardiopulmonary bypass (CPB). It is also aimed to reduce the inflammatory response by further increasing the biocompatibility of the components that make up the MiECC circuits. The Minithoracotomy (MTH) approach for mitral valve disease remains associated with prolonged operative times, but it is beneficial in terms of reduced postoperative complications (renal failure, atrial fibrillation, blood transfusion, wound infection), length of stay in intensive care unit (ICU) and in hospitalization, with finally a reduction in global cost. Combining the use of the MiECC technique with minimally invasive mitral valve surgery (MIMVS) could open up new research scenarios. Although considerable progress has been made in the standardization of the surgical technique, limitations remain to be filled in the setting of Endo-cavitary aspiration for the association of MiECC with MIMVS. In this paper we introduce invention refers to a device and an air-closed endocavitary aspiration system for cardiac chamber surgery, as well as a method aimed at eliminating gaseous micro-embolic activity, hemolysis and CO2 aspiration and alteration of carbon dioxide production (VCO2) the parameters for goal directed perfusion. The system allows the surgery of the cardiac chambers to be associated with a minimally invasive extra-corporeal circulation circuit.

The Influence of High-Dose Parenteral Vitamin C on the Incidence and Severity of Postoperative Pulmonary Complications in Cardiac Surgery with Extracorporeal Circulation: A Randomized Controlled Trial.

Cardiac surgery (CS) with extracorporeal circulation (ECC), induces intense oxidative stress (OS) and systemic inflammatory response (SIR), which may seriously affect postoperative lung function. We aimed to test if high parenteral (200 mg/kg/24 h) daily doses of Vitamin C (VitC), given within 48 h after the beginning of the operation, may reduce the incidence and severity of postoperative pulmonary complications (PPCs) in CS patients. This single-center, prospective, randomized, single-blinded, interventional trial included 150 patients, assigned to control Group A (n = 75) and interventional Group B (n = 75). Group B intraoperatively received one-fourth (i.e., 50 mg/kg) of the planned daily Vit C dose, divided into three equal parts and diluted in 10 mL of normal saline, while Group A received an equal volume of normal saline at the same time frames (i.e., the induction of anesthesia, aortic cross-clamp release, and sternal closure). After 6 h from the first intraoperative dose, the following regimen was applied: Group B: 50 mg/kg, 30 min i.v. infusion of VitC in 50 mL of normal saline, every 6 h, for the next 48 h, and Group A: 30 min i.v. infusion of an equal volume of normal saline every 6 h, for the next 48 h. Modified Kroenke's score was used to determine the incidence and severity of PPCs. The overall incidence of PPCs was 36.7% and was significantly lower in Group B (13.3% vs. 60.0%, p < 0.001). The PPCs severity score was also significantly lower in Group B (1 vs. 3, p < 0.001). In addition, patients from Group B had significantly less damaged lungs, better postoperative renal function, shorter ICU stays, fewer ICU re-admissions, and lower hospital mortality. No VitC-related adverse effects were recorded. High parenteral daily VitC doses given within 48 h after the beginning of CS are safe and effective in reducing the incidence and severity of PPCs. A multicenter RCT is needed to confirm these results.

Outcomes of Extracorporeal Life Support (ECLS) in Acute Severe Asthma: A Narrative Review.

BACKGROUND: In this narrative review we aimed to explore outcomes of extracorporeal life support (extracorporeal membrane oxygenation (ECMO) and extracorporeal carbon dioxide removal (ECCO2R)) as rescue therapy in patients with status asthmaticus requiring mechanical ventilation. METHODS: Multiple databases were searched for studies fulfilling inclusion criteria. Articles reporting mortality and complications of ECMO and ECCO2R in mechanically ventilated patients with acute severe asthma (ASA) were included. Pooled estimates of mortality and complications were obtained by fitting Poisson's normal modeling. RESULTS: Six retrospective studies fulfilled inclusion criteria thus yielding a pooled mortality rate of 17% (13-20%), pooled risk of bleeding of 22% (7-37%), mechanical complications in 26% (21-31%), infection in 8% (0-21%) and pneumothorax rate 4% (2-6%). CONCLUSION: Our review identified a variation between institutions in the initiation of ECMO and ECCO2R in patients with status asthmaticus and discrepancy in the severity of illness at the time of cannulation. Despite that, mortality in these studies was relatively low with some studies reporting no mortality which could be attributed to selection bias. While ECMO and ECCO2R use in severe asthma patients is associated with complication risks, further studies exploring the use of ECMO and ECCO2R with mechanical ventilation are required to identify patients with favorable risk benefit ratio.

A Split-Lung Ex Vivo Perfusion Model for Time- and Cost-Effective Evaluation of Therapeutic Interventions to the Human Donor Lung.

With the ongoing shortage of donor lungs, ex vivo lung perfusion (EVLP) offers the opportunity for objective assessment and potential therapeutic repair of marginal organs. There is a need for robust research on EVLP interventions to increase the number of transplantable organs. The use of human lungs, which have been declined for transplant, for these studies is preferable to animal organs and is indeed essential if clinical translation is to be achieved. However, experimental human EVLP is time-consuming and expensive, limiting the rate at which promising interventions can be assessed. A split-lung EVLP model, which allows stable perfusion and ventilation of two single lungs from the same donor, offers advantages scientifically, financially and in time to yield results. Identical parallel circuits allow one to receive an intervention and the other to act as a control, removing inter-donor variation between study groups. Continuous hemodynamic and airway parameters are recorded and blood gas, perfusate, and tissue sampling are facilitated. Pulmonary edema is assessed directly using ultrasound, and indirectly using the lung tissue wet:dry ratio. Evans blue dye leaks into the tissue and can quantify vascular endothelial permeability. The split-lung ex vivo perfusion model offers a cost-effective, reliable platform for testing therapeutic interventions with relatively small sample sizes.

Contralateral Thoracotomy With Extracorporeal Circulation for Reoperative Resection of a Kommerell Diverticulum.

Reoperative vascular ring surgery is uncommon. Standard redo ipsilateral thoracotomy may present technical challenges and risks. We describe a patient with right aortic arch, aberrant left subclavian artery, and a Kommerell diverticulum in whom previous vascular ring division via left thoracotomy did not relieve dysphagia. Three years after the unsuccessful operation, left subclavian-carotid transposition via supraclavicular incision followed by resection of the Kommerell diverticulum via right thoracotomy with extracorporeal circulation relieved symptoms. Contralateral thoracotomy with extracorporeal circulation provides a safe, alternative approach to redo ipsilateral thoracotomy for resection of a symptomatic Kommerell diverticulum. We review the literature on the incidence, surgical indications, and operative approaches to manage symptoms from a Kommerell diverticulum.

Extracorporeal Carbon Dioxide Removal to Avoid Invasive Ventilation During Exacerbations of Chronic Obstructive Pulmonary Disease: VENT-AVOID Trial - A Randomized Clinical Trial.

Rationale: It is unclear whether extracorporeal CO2 removal (ECCO2R) can reduce the rate of intubation or the total time on invasive mechanical ventilation (IMV) in adults experiencing an exacerbation of chronic obstructive pulmonary disease (COPD). Objectives: To determine whether ECCO2R increases the number of ventilator-free days within the first 5 days postrandomization (VFD-5) in exacerbation of COPD in patients who are either failing noninvasive ventilation (NIV) or who are failing to wean from IMV. Methods: This randomized clinical trial was conducted in 41 U.S. institutions (2018-2022) (ClinicalTrials.gov ID: NCT03255057). Subjects were randomized to receive either standard care with venovenous ECCO2R (NIV stratum: n = 26; IMV stratum: n = 32) or standard care alone (NIV stratum: n = 22; IMV stratum: n = 33). Measurements and Main Results: The trial was stopped early because of slow enrollment and enrolled 113 subjects of the planned sample size of 180. There was no significant difference in the median VFD-5 between the arms controlled by strata (P = 0.36). In the NIV stratum, the median VFD-5 for both arms was 5 days (median shift = 0.0; 95% confidence interval [CI]: 0.0-0.0). In the IMV stratum, the median VFD-5 in the standard care and ECCO2R arms were 0.25 and 2 days, respectively; median shift = 0.00 (95% confidence interval: 0.00-1.25). In the NIV stratum, all-cause in-hospital mortality was significantly higher in the ECCO2R arm (22% vs. 0%, P = 0.02) with no difference in the IMV stratum (17% vs. 15%, P = 0.73). Conclusions: In subjects with exacerbation of COPD, the use of ECCO2R compared with standard care did not improve VFD-5. Clinical trial registered with www.clinicaltrials.gov (NCT03255057).

Beating Heart Transplants-Overview and Implications for Anesthesiologists.

As the demand for heart allografts for transplantation continues to rise, ex vivo organ perfusion strategies are playing an increasingly important role in the preservation of organs from donation after circulatory death and extended-criteria donors. One such method uses the Organ Care System (TransMedics, Andover, MA). Traditionally, this technique of preservation requires 2 periods of warm ischemia and subsequent cardioplegic arrest. In a novel surgical technique pioneered at the authors' institution, heart allograft implantation no longer requires a second cardioplegic arrest. This article discusses the surgical approach for this procedure, the advantages and disadvantages of this approach, and analogs to current clinical practice to theorize what impact this may have on cardiac transplantation volumes in the future.

High-molecular-weight linear polymers improve microvascular perfusion after extracorporeal circulation.

High-molecular-weight linear polymers (HMWLPs) have earned the name "drag-reducing polymers" because of their ability to reduce drag in turbulent flows. Recently, these polymers have become popular in bioengineering applications. This study investigated whether the addition of HMWLP in a venoarterial extracorporeal circulation (ECC) model could improve microvascular perfusion and oxygenation. Golden Syrian hamsters were instrumented with a dorsal skinfold window chamber and subjected to ECC using a circuit comprised of a peristaltic pump and a bubble trap. The circuit was primed with lactated Ringer solution (LR) containing either 5 ppm of polyethylene glycol (PEG) with a low molecular weight of 500 kDa (PEG500k) or 5 ppm of PEG with a high molecular weight of 3,500 kDa (PEG3500k). After 90 min of ECC at 15% of the animal's cardiac output, the results showed that the addition of PEG3500k to LR improved microvascular blood flow in arterioles and venules acutely (2 h after ECC), whereas functional capillary density showed improvement up to 24 h after ECC. Similarly, PEG3500k improved venular hemoglobin O2 saturation on the following day after ECC. The serum and various excised organs all displayed reduced inflammation with the addition of PEG3500k, and several of these organs also had a reduction in markers of damage with the HMWLPs compared to LR alone. These promising results suggest that the addition of small amounts of PEG3500k can help mitigate the loss of microcirculatory function and reduce the inflammatory response from ECC procedures.NEW & NOTEWORTHY High-molecular-weight linear polymers have gained traction in bioengineering applications. The addition of PEG3500k to lactated Ringer solution (LR) improved microvascular blood flow in arterioles and venules acutely after extracorporeal circulation (ECC) in a hamster model and improved functional capillary density up to 24 h after ECC. PEG3500k improved venular hemoglobin O2 saturation and oxygen delivery acutely after ECC and reduced inflammation in various organs compared to LR alone.

Use of Subclavian Extracorporeal Carbon Dioxide Removal for COVID-19 Acute Respiratory Distress Syndrome as a Bridge to Lung Transplantation.

Severe acute hypercapnia is independently associated with increased adverse effects and intensive care unit mortality in mechanically ventilated patients. During the severe acute respiratory syndrome coronavirus 2 (COVID-19) pandemic, some patients were placed on extracorporeal carbon dioxide removal support when extracorporeal membrane oxygenation (ECMO) support was at capacity or not offered. We present a patient with severe acute respiratory distress syndrome caused by COVID-19 pneumonia, who was supported with Hemolung Respiratory Assist System (ALung Technologies, Inc., LivaNova, Pittsburgh, PA) via the right subclavian vein as a bridge to lung transplantation after venovenous ECMO support. The patient survived and was discharged home.

Genetic Modulation: Future Trends Toward Graft Optimization During Machine Perfusion.

Dynamic preservation methods such as normothermic, subnormothermic, and hypothermic machine perfusion circuits have emerged as viable alternatives to conventional static cold storage. These organ perfusion technologies serve as preservation methods and enable organ assessment, reconditioning, and repair before transplantation. Gene therapy is a novel strategy with the potential to transform the field of graft optimization and treatment. Thereby specific pathways involved in the transplantation process can be targeted and modified. This review aims to provide an overview of gene delivery methods during ex vivo machine perfusion of kidney and liver grafts. Recent literature on state-of-the-art gene therapy approaches during ex situ organ preservation, especially with respect to ischemia-reperfusion injury, as well as acute and chronic graft rejection have been analyzed. Additionally, potential challenges that could affect further refinement of this therapeutic modality are outlined.

Recovery of extracorporeal lungs using cross-circulation with injured recipient swine.

OBJECTIVE: Lung transplantation remains limited by the shortage of healthy organs. Cross-circulation with a healthy swine recipient provides a durable physiologic environment to recover injured donor lungs. In a clinical application, a recipient awaiting lung transplantation could be placed on cross-circulation to recover damaged donor lungs, enabling eventual transplantation. Our objective was to assess the ability of recipient swine with respiratory compromise to tolerate cross-circulation and support recovery of donor lungs subjected to extended cold ischemia. METHODS: Swine donor lungs (n = 6) were stored at 4 °C for 24 hours while recipient swine (n = 6) underwent gastric aspiration injury before cross-circulation. Longitudinal multiscale analyses (blood gas, bronchoscopy, radiography, histopathology, cytokine quantification) were performed to evaluate recipient swine and extracorporeal lungs on cross-circulation. RESULTS: Recipient swine lung injury resulted in sustained, impaired oxygenation (arterial oxygen tension/inspired oxygen fraction ratio 205 ± 39 mm Hg vs 454 ± 111 mm Hg at baseline). Radiographic, bronchoscopic, and histologic assessments demonstrated bilateral infiltrates, airway cytokine elevation, and significantly worsened lung injury scores. Recipient swine provided sufficient metabolic support for extracorporeal lungs to demonstrate robust functional improvement (0 hours, arterial oxygen tension/inspired oxygen fraction ratio 138 ± 28.2 mm Hg; 24 hours, 539 ± 156 mm Hg). Multiscale analyses demonstrated improved gross appearance, aeration, and cellular regeneration in extracorporeal lungs by 24 hours. CONCLUSIONS: We demonstrate that acutely injured recipient swine tolerate cross-circulation and enable recovery of donor lungs subjected to extended cold storage. This proof-of-concept study supports feasibility of cross-circulation for recipients with isolated lung disease who are candidates for this clinical application.

Treatment of Staphylococcus aureus infection with sphingosine in ex vivo perfused and ventilated lungs.

BACKGROUND: Ex vivo lung perfusion (EVLP) has expanded the donor pool for lung transplantation. Pulmonary Staphylococcus aureus infection, especially that caused by multidrug-resistant strains, is a severe threat to posttransplantation outcomes. Sphingosine is a lipid compound that exhibits broad-spectrum antibacterial activity. Therefore, we aimed to evaluate the effects of S aureus infection on EVLP and whether sphingosine administration during EVLP prevents infection with S aureus. METHODS: Eighteen pigs were randomly assigned to 3 groups: uninfected, infected with S aureus with NaCl treatment, or infected with sphingosine treatment. Bacterial numbers were determined before and after treatment. Sphingosine concentrations in the lung tissues were determined using biochemical assays. Lung histology, lung physiological parameters, perfusate content, lung weight, and cell death were measured to analyze the effects of infection and sphingosine administration on EVLP. RESULTS: Sphingosine administration significantly reduced the bacterial load. The concentration of sphingosine in the bronchial epithelium was elevated after sphingosine administration. S aureus infection increased pulmonary artery pressure and pulmonary vascular resistance. Lung edema, histology scores, lactate and lactate dehydrogenase levels in the perfusate, ΔPO2 in the perfusate, static lung compliance, and lung peak airway pressure did not differ among the groups. CONCLUSIONS: Infection of S aureus did not affect the lung function during EVLP but induced higher pulmonary artery pressure and pulmonary vascular resistance. Administration of sphingosine effectively eliminated S aureus without side effects in isolated, perfused, and ventilated pig lungs.

Exploring clinical evaluation indicators for predicting coagulation in the extracorporeal circulation circuit in hemodialysis patients receiving individualized regional citrate anticoagulation-A single-center, retrospective clinical study.

BACKGROUND: Citrate anticoagulation is an important anticoagulation method in hemodialysis (HD) but cannot completely prevent the occurrence of coagulation in the extracorporeal circulation (ECC) circuit, and the clinical coagulation status can significantly affect the effect of citrate anticoagulation. In this study, the relationships between clinical coagulation status indicators and coagulation in the ECC circuit in HD patients receiving individualized citrate anticoagulant were studied to explore indicators that may predict coagulation in the ECC circuit. METHODS: This study was a single-center, retrospective clinical study, and clinical data and laboratory tests related to the coagulation status of HD patients receiving individualized regional citrate anticoagulation (RCA) were collected. The relationships between indicators commonly used in clinical practice to evaluate clinical coagulation status and coagulation in the ECC circuit were statistically analyzed to find indicators that can predict the occurrence of coagulation in the ECC circuit. RESULTS: The individualized RCA had a good anticoagulation effect, and the actual citrate infusion rate in nearly 80% of the patients was within ±10% of the theoretical infusion rate. The combined diseases or conditions that affect the coagulation status in vivo may increase the incidence of coagulation in the ECC circuit. The clinical D-dimer level is an independent risk factor that affects and can predict coagulation in the ECC circuit, with a cutoff value of 2.03 mg/L, sensitivity of 59%, and specificity of 78%. CONCLUSION: Individualized RCA can meet the needs of most HD treatments. Abnormal coagulation status in HD patients may increase the incidence of coagulation in the ECC circuit during individualized RCA for HD, and the D-dimer level can predict the occurrence of coagulation in the ECC circuit during this treatment.