ASAIO Journal最新文献

Normothermic machine perfusion (NMP) has emerged as a valuable preservation technique in liver transplantation, offering improved graft assessment and viability. Traditionally, liver grafts undergo a second cooling phase before implantation, which may contribute to cellular damage through ischemia-reperfusion injury. In this "How To Do It" article, we describe our surgical technique to avoid re-cooling following NMP. Specifically, after retrieval from the perfusion device, the graft is directly inserted into the surgical field and undergoes a standardized portal flush with 1 L of 5% albumin at room temperature before reperfusion. This method maintains physiological temperature, potentially reducing reperfusion stress and enhancing graft function. We detail step-by-step procedural aspects, including organ handling, vascular anastomoses, and intraoperative considerations, supported by our clinical outcomes.

Venopulmonary arterial (VPA) extracorporeal membrane oxygenation (ECMO) is emerging as an alternative to traditional venovenous (VV) ECMO for respiratory failure. This study compares rates of hemolysis and acute kidney injury (AKI) between VPA and VV ECMO. We retrospectively analyzed 142 patients (VPA: n = 84, VV: n = 58) who underwent ECMO from 2019 to 2023. Plasma-free hemoglobin (pfHb) was measured as a marker for hemolysis and AKI was assessed using daily creatinine levels. Mixed-effects linear regression and Cox proportional hazards models were used to assess associations between ECMO modality, hemolysis, and AKI. No significant differences in pfHb, creatinine, or AKI incidence were observed between VV and VPA ECMO ( p > 0.05). Extracorporeal membrane oxygenation modality was not a significant predictor of pfHb levels ( p = 0.376), creatinine levels ( p = 0.337), or time to AKI (hazard ratio [HR] = 0.94, 95% confidence interval [CI] = 0.39-2.30; p = 0.898). Centrimag pumps were associated with lower pfHb compared with Cardiohelp (29% reduction, p = 0.002). Increased pump speed correlated with elevated pfHb (27% increase per 1,000 RPM, p = 0.003). Venopulmonary arterial and VV ECMO demonstrate similar hemolysis and AKI profiles. Pump type and speed significantly influence hemolysis, emphasizing the importance of optimal ECMO configuration and management in minimizing complications.

Currently, no clinical modality reliably assists clinicians in selecting the optimal transcatheter aortic valve replacement (TAVR) device orientation. This is critical for the growing population of young bicuspid aortic valve (BAV) TAVR candidates, who are at high risk for post-procedural complications. We aim to develop a predictive computational modeling workflow to identify which TAVR device and orientation will minimize the risk of paravalvular leakage (PVL), coronary obstruction, and flow-induced thrombogenicity. We compared the risk of post-TAVR complications across more than 30 device orientation combinations by virtually implanting self-expandable and balloon-expandable TAVR devices in three BAV patients. PVL severity varied significantly with device orientation, reaching up to 22.03 mL/beat with certain self-expandable devices. For self-expandable devices, orientations that ensured the shortest distance between the taller skirt region and PVL regions minimized PVL. A shorter frame height in balloon-expandable devices was insufficient to cover PVL regions in certain patients. Pearson correlation demonstrated a negative relationship between device oversizing and PVL. The risk of flow-induced thrombogenicity was positively correlated with PVL severity. A patient-specific computational modeling workflow can identify the optimal TAVR device and orientation, minimizing life-threatening post-TAVR complications and facilitating future reinterventions for young BAV TAVR candidates.

The aortic pulsatility index (API) (systolic blood pressure-diastolic blood pressure/pulmonary capillary wedge pressure [PCWP]) integrates ventricular output with left ventricular (LV) filling pressures. It offers a surrogate for ventricular-arterial coupling and is associated with the need for advanced therapies and outcomes in decompensated heart failure. However, its use in patients in cardiogenic shock requiring temporary mechanical circulatory support (tMCS) is limited and requires invasive measurement of PCWP. This case series evaluates the concept of echo-API as a noninvasive tool to estimate API using Doppler echocardiography, and its feasibility in patients with cardiogenic shock on tMCS.

This study investigated factors influencing recirculation in veno-venous extracorporeal membrane oxygenation (VV ECMO) using a controlled bench model comprising a VV ECMO circuit and a mock circulatory loop with a porcine cadaver heart simulating human right heart anatomy. Several single-lumen cannula (SLC) configurations (15/21 Fr, 15/23 Fr, 17/21 Fr, 17/23 Fr) and double-lumen cannulae (DLC) from two manufacturers were evaluated. Different cannula positions (distance, rotation), ECMO flow (ECF), cardiac output (CO), central venous pressure (CVP) were assessed for their impact on recirculation, measured by ultrasound dilution method. In 31 experimental series (1,641 measurements), increasing CO consistently reduced recirculation, irrespective of cannulation configuration (SLC: R = -0.99; DLC: R = -0.87; p < 0.01), whereas elevating ECF increased it. CO/ECF ratio had a greater impact than CO or ECF alone, with higher values reducing recirculation in both SLC and DLC. In SLC, cannula size or retraction beyond a threshold distance had minimal effect on recirculation. However, in DLCs exact positioning is crucial, as suboptimal placement or rotation markedly increased recirculation.CO and CO/ECF ratio are key determinants of recirculation in all cannulation scenarios. In clinical settings, accurate monitoring of recirculation and CO is essential to optimize VV ECMO oxygen transfer efficiency and should become standard troubleshooting practice.

During extracorporeal membrane oxygenation (ECMO) decannulation, blood loss often occurs, leading to anemia and the need for blood transfusions. This article presents an improved ECMO pump-controlled blood reinfusion technique designed to address these challenges. The proposed method offers a simple and effective solution to minimize blood loss and reduce the need for additional blood transfusions during ECMO procedures. This technique significantly reduces blood loss and transfusion needs, offering a safer, more efficient approach to ECMO management in critical care.

The geometric configuration of fiber bundles plays a critical role in gas transfer for membrane oxygenators; however, experimentally studying its impact on gas transfer distribution is challenging. This study numerically examines oxygen and carbon dioxide transfer processes in a mini-oxygenator with a fiber bundle, focusing on the effects of inlet blood flow rate, fiber bundle cross-sectional area, fiber spacing, and wall effects. The numerical model, validated against existing data, was used to analyze blood gas parameter distribution under varying conditions. The findings indicate that an increase in blood inlet flow rate delays oxygen saturation and reduces the partial pressure of oxygen at the same location within the fiber bundle. Furthermore, the cross-sectional area perpendicular to the inlet flow direction, when maintaining a consistent fiber bundle volume, noticeably impacts gas exchange performance. Fiber spacing strongly affects carbon dioxide-related parameters but has negligible impact on oxygen-related parameters. The wall effect on gas transfer is limited to the outermost fiber layer adjacent to the wall. These studies elucidate the relationship between gas transfer performance and geometric factors, thereby providing insights for optimizing fiber bundle geometry in the design of membrane oxygenators to enhance efficiency and effectiveness.