ASAIO Journal最新文献

Extracorporeal membrane oxygenation (ECMO) represents an established modality of intraoperative circulatory and respiratory support during lung transplantation (LTx). Systemic anticoagulation with unfractionated heparin (UFH) remains essential to prevent circuit thrombosis; however, the optimal monitoring strategy during this procedure remains uncertain. Conventional assays, including antifactor Xa activity (anti-Xa), activated partial thromboplastin time (aPTT), aPTT ratio (aPTTr), and activated clotting time (ACT), demonstrate variable sensitivity and reliability, particularly at low UFH concentrations where ACT is often inadequate. This study aimed to evaluate the interrelationship between standard coagulation monitoring methods and to assess the feasibility of using viscoelastic testing, specifically the ROTEM INTEM/HEPTEM clotting time ratio (I/Hr), as a bedside alternative to ACT. A total of 79 patients undergoing LTx with intraoperative ECMO support were analyzed. Unfractionated heparin was administered in all cases, and coagulation parameters were assessed preoperatively, before ECMO cannulation, and during ECMO support. A strong correlation was observed between I/Hr and anti-Xa, with satisfactory agreement with aPTT and aPTTr. Bland-Altman analysis confirmed narrower limits of agreement for I/Hr-derived versus ACT-derived anti-Xa predictions. These findings support I/Hr as a reliable and practical bedside surrogate for UFH monitoring during ECMO-assisted LTx.

The current study aimed to assess the national practice patterns of extracorporeal membrane oxygenation (ECMO) use during the early posttransplant period. We included patients in the United Network for Organ Sharing (UNOS) database aged greater than 18 years who underwent lung transplantation (LT) between January 1, 2017 and December 31, 2022 (n = 14,999). The study group was divided based on the need for ECMO at 72 hours after LT, as recorded in the database. We analyzed recipient, donor, and procedure-related variables as potential predictors of need for ECMO. One year survival was the primary outcome variable. The overall incidence of ECMO use after LT was 9% (1,357/14,999), with increasing yearly incidence (6.5%-10.7%). Several recipient variables were independently associated with post-LT ECMO use. Additionally, older donors, donation after circulatory death donors, use of machine perfusion, longer ischemia time, and bilateral LT were additional predictors. Patients with post-LT ECMO use had significantly higher 1 year mortality (30.5% vs. 9%, p < 0.001). It is concluded that post-LT ECMO use was independently associated with worse 1 year mortality. Extracorporeal membrane oxygenation is being increasingly deployed among patients with severe allograft dysfunction. The increase in incidence of post-LT ECMO use appears to be fueled by progressively higher-risk donors and recipients. Patients with post-LT ECMO use continue to experience markedly worse outcomes.

To examine the global epidemiology of extracorporeal membrane oxygenation discontinuation due to resource limitation (EDRL), assessing differences across geographic regions and between pre- and post-coronavirus disease 2019 (COVID-19) periods. Retrospective cohort analysis of all children and adults from international ECMO centers (2013-2023) in which ECMO was discontinued due to resource limitations. Of the 161,851 ECMO runs, 312 (0.19%) underwent EDRL. Of those, 25% occurred in children. Leading diagnoses were cardiogenic shock (n = 62, 20%) and COVID-19 (n = 33, 11%). Twelve percent survived post-EDRL and 29% were transported on ECMO for resource reallocation. Extracorporeal membrane oxygenation discontinuation due to resource limitations increased worldwide over time, particularly following COVID-19 (1.44 EDRLs per 1,000 ECMO runs vs. 2.44 EDRLs per 1,000 ECMO runs, p < 0.001), disproportionately to the overall increase in ECMO utilization (p = 0.019), especially in Europe (p < 0.001) and North America (p = 0.003). Latin America and Southwest Asia/Africa exhibited high proportions of EDRLs relative to ECMO runs (12.8 and 4.8 per 1,000 cannulations, respectively) and low post-EDRL survival rates (6.7% and 0%, respectively). Resource limitation remains a rare indication for ECMO decannulation, differs across global regions, and has grown over time disproportionately to the overall increase in ECMO use, particularly in Europe and North America and with the onset of the COVID-19 pandemic.

Chondrocytes are a primary cell type used in articular cartilage tissue engineering due to their ability to be applied autologously, minimizing the risk of immune rejection. However, isolated chondrocytes often exhibit heterogeneity, including mixtures of viable, dead, and dedifferentiated cells, which may impact their functional properties. In this study, the hydrophobicity and surface tension components of chondrocytes isolated from healthy and osteoarthritis (OA) donors were explored using a drop shape analyzer and Young's-Dupré equation over a 21 day culture period. The results indicate that OA-derived chondrocytes consistently exhibited higher water contact angles than healthy chondrocytes, with statistically significant differences observed on days 0, 7, and 14 of culture. The amounts of all three components of surface tension in healthy chondrocytes were significantly higher than those in OA-derived chondrocytes, except for van der Waals forces on day 0. Additionally, the observed modulation of chondrocyte hydrophobicity over the 21 day culture period indicates a potential functional phenotype shift from OA state toward a healthier phenotype under standard culture conditions. These results not only highlight hydrophobicity and surface tension as potential biomarkers for distinguishing OA and healthy chondrocytes, but also suggest possible therapeutic strategies aimed at restoring OA chondrocytes to a healthy state.

Hydrogen has emerged as a therapeutic agent in inflammatory critical illnesses due to its potential to modulate inflammation and oxidative stress. However, its role in extracorporeal membrane oxygenation (ECMO), a life-saving intervention for severe cardiorespiratory failure associated with pronounced inflammation and oxidative stress, remains largely unexplored. This ex vivo study investigated whether ECMO could serve as an effective vehicle for hydrogen delivery. It also evaluated hydrogen's effects on oxidative stress, inflammation, and coagulation responses arising from the interaction between human blood and non-biological ECMO surfaces. Four healthy male volunteers each provided two blood donations, 6 months apart. We assigned human blood-filled ECMO circuits to two different sweep gas formulations: a CO₂-enriched gas mixture (n = 4) or a mixture of 2% hydrogen in CO₂-enriched gas (n = 4). At T0, stable hydrogen concentrations (9.82 ± 1.97 μmol/L) were achieved and maintained for 6 hours, confirming the reliability of the hydrogen delivery method. Hydrogen exposure significantly reduced collagen (p = 0.01), TRAP-6 (p = 0.04), and ADP-induced (p = 0.04) platelet aggregation and showed a trend toward reduction in oxidative stress markers. In conclusion, this preliminary ex vivo study demonstrates the feasibility of delivering hydrogen gas via the sweep gas of a clinically established ECMO machine and its initial effects on blood, warranting further investigation in larger preclinical animal models.

Computational fluid dynamics (CFD) is increasingly important in biomedical engineering; however, its use in medical device design remains constrained by regulatory requirements for model validation and verification. To address this, the Food and Drug Administration (FDA) proposed a benchmark nozzle geometry for standardized validation. This study employs a turbulence-based hemolysis model-the Ozturk-Papavassiliou-O'Rear (OPO) model-to investigate the FDA nozzle and identify red blood cell (RBC) damage caused by eddy structures similar in size to RBCs. Flow simulations were conducted for sudden contraction (SC) and gradual cone (GC) nozzle configurations at inlet velocities of 0.46 and 0.6 m/s (throat Reynolds of 3,500 and 6,500). Regions where eddies fall within the damaging Kolmogorov length scale were identified and analyzed. Hemolysis predictions were made using the eddy surface area distribution and validated against experimental hemolysis index (HI) data. For SC, a qualitative indicator, the cumulative eddy surface area of 6-20 μm, was provided; a numerical HI was postponed until a recalibration specific to SC and independent verification. For GC, the OPO model reproduced experimental trends in hemolysis risk localization but underpredicted absolute HI. These findings suggest that the OPO model offers a viable approach to predicting turbulence-resolved hemolysis in medical device design.

Delays in mechanical circulatory support (MCS) for cardiogenic shock can be critical. However, timely access to a hybrid operating room or C-arm fluoroscopy for urgent axillary Impella 5.5 (Abiomed, Danvers, MA) implantation remains a barrier. To address this, we developed a fluoroscopy-free axillary Impella 5.5 implantation technique using transesophageal echocardiography (TEE) guidance. From January 2023 to November 2024, 19 adults underwent the procedure. A preoperative flowchart ensured appropriate selection, with the right axillary artery as the preferred access. Transesophageal echocardiography-guided pigtail advancement, valve crossing, and device positioning. All implantations (100%) were successful without conversion to fluoroscopy-guided or ECMO. There were no strokes or major complications. All patients had optimal positioning and rapid hemodynamic improvement. These findings support the feasibility and safety of TEE-guided, fluoroscopy-free Impella 5.5 implantation. It offers a significant benefit for earlier implantation of MCS in patients with cardiogenic shock, especially in settings where limited or delayed access to fluoroscopic imaging resources is a barrier to timely intervention.