Artificial organs最新文献

Transcatheter aortic valve implantation (TAVI) has become the preferred treatment for aortic stenosis in the elderly. However, the durability of transcatheter heart valves (THV) and the risk of leaflet thrombosis preclude the extension of TAVI in young people. This study sought to formulate a proof-of-concept solution for non-invasive, continuous monitoring of THV function using photoplethysmography (PPG) sensors and machine learning models. An in vitro mock circulatory loop was developed using a compliant aortic phantom and an implanted self-expanding Evolut FX device. Two PPG sensors were attached to the phantom surface to record flow signals during various hemodynamic scenarios generated by Latin Hypercube Sampling. Endoscopic imaging measurements of the geometric orifice area (GOA) were used to assess valve performance. PPG-derived metrics and flow variables were used to train regression and classification models that predicted healthy versus decreased leaflet motion. The regression model showed an R² of 0.83, RMSE of 7.18 mm², and MAE of 5.58 mm². The classifier correctly identified reduced leaflet motion (95% accuracy, 0.89 precision, and 0.91 recall). This study demonstrates the efficacy of PPG sensors and machine learning for non-invasive THV monitoring. The approach offers a promising tool for early detection of leaflet dysfunction, thereby improving the management of TAVI patients.

Background: Surgical femoral arterial decannulation following venoarterial extracorporeal membrane oxygenation (V-A ECMO) can lead to serious vascular complications. Among surgical options, the purse-string method has gained attention as a potentially simpler and less invasive alternative. However, clinical data evaluating its safety and feasibility remain limited.

Methods: We retrospectively analyzed 325 adult patients who underwent femoral arterial decannulation following V-A ECMO support from 2012 to 2023 at a single tertiary center. Of these, 87 patients received decannulation using the purse-string technique. Propensity score matching was used to contextualize outcomes relative to the conventional cross-clamp method.

Results: The purse-string technique significantly reduced operative time (132.9 ± 88.5 vs. 74.1 ± 36.9 min; p < 0.001) without increasing reintervention rates. Most reinterventions in the purse-string group were detected by early imaging surveillance, while cross-clamp patients more frequently presented with symptomatic complications such as acute ischemia. Vessel injuries and late vascular complications occurred exclusively in the cross-clamp group. No patient in the purse-string cohort experienced permanent limb loss or amputation.

Conclusion: The purse-string technique enables efficient and safe decannulation after V-A ECMO, offering a less invasive alternative to cross-clamp repair. This less invasive method may be particularly advantageous in critically ill patients or bedside settings where minimizing operative time and vascular trauma is essential.

To date, it remains unclear to what extent dialyzer performance is affected by clotting, and which hemocompatibility parameters can reliably predict this phenomenon. This study investigated the relationship between dialyzer clotting, performance, and hemocompatibility in four commercially available dialyzers under conditions of intentionally reduced anticoagulation. This crossover study included 10 chronic hemodialysis patients, who were randomized over four dialyzers: FX CorAL800, FX CorDiax800, xevonta Hi20 (all polysulfone-based), and Solacea-19H (cellulose-based). Patients received a single bolus of one-quarter of their standard Low-Molecular-Weight Heparin (LMWH) dose. Dialysis efficiency was assessed from toxin clearance of urea, β2-microglobulin, and myoglobin. Fiber patency was evaluated through visual scoring and μCT imaging. Hemocompatibility markers, including platelet counts, leukocyte counts, anti-Xa activity, thrombin-antithrombin complex (TAT), beta-thromboglobulin (β-TG), and neutrophil-activating peptide (NAP-2), were also analyzed. μCT analysis showed that Solacea dialyzer demonstrated superior fiber patency compared to the other dialyzers. However, fiber blockage did not compromise dialysis performance, as all dialyzers maintained effective toxin removal. Platelet and leukocyte counts remained stable with FX CorAL and Solacea, while declines were found in FX CorDiax and xevonta. No significant correlations were found between clotting parameters and fiber blockage. Hence, under reduced anticoagulation, the cellulose-based Solacea dialyzer exhibited superior fiber patency, but this did not result in higher middle molecule clearance. Since no correlation was found between fiber patency, dialysis performance, or clotting parameters, the underlying cause of the observed differences in dialyzer blockage remains unclear.

Purpose: The mesonephric kidney of fish retains its capacity for nephrogenesis and regeneration throughout the organism's lifetime. It is hypothesized that the extracellular matrix (ECM) of trout plays a pivotal role in supporting the proliferation and differentiation of resident cells. The ECM is a complex three-dimensional network of macromolecules secreted by cells during early development and is essential for regulating key cellular functions, including adhesion, migration, proliferation, differentiation, and survival. This study aimed to evaluate the effects of decellularized trout kidney ECM on the growth and differentiation of mouse renal tubular epithelial cells in vitro.

Method: In this study, trout kidneys were decellularized and bleached using a combination of sodium dodecyl sulfate (SDS), Triton X-100, and a bleaching buffer. The effectiveness of decellularization was evaluated using quantitative assays and histological staining. The resulting ECM was then coated onto culture dishes at concentrations of 100 and 150 μg/cm². To assess potential cytotoxicity, an indirect extraction assay was performed. Subsequently, human bone marrow-derived mesenchymal stem cells (hMSCs) were seeded onto the decellularized ECM. Cell viability and proliferation were evaluated using the MTS assay [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] and the CFSE (carboxyfluorescein succinimidyl ester) assay, respectively, and results were compared to an uncoated control group. Finally, gene expression analysis of hMSCs was conducted using quantitative reverse transcription polymerase chain reaction (qRT-PCR).

Findings: The decellularization of fish renal ECM was successfully achieved. Quantitative and qualitative analyses confirmed a significant reduction in DNA content in the decellularized tissue compared to native samples, indicating effective removal of cellular material. At the same time, key ECM components such as collagen and sulfated glycosaminoglycans (sGAGs) were preserved to a substantial extent. Specifically, collagen content decreased from 5.736 μg/mg in native tissue to 4.284 μg/mg in the decellularized ECM, while sGAG content showed a slight decrease from 0.9855 μg/mg to 0.9400 μg/mg, reflecting minimal degradation during processing. Cytotoxicity assessment revealed no toxic effects associated with the decellularized matrices. Furthermore, a significant increase in the proliferation of human mesenchymal stem cells (hMSCs) was observed on day 7 compared to the uncoated control group, suggesting the bioactivity and compatibility of the decellularized trout kidney ECM.

Background: Cannulation for peripheral veno-arterial extracorporeal membrane oxygenation (V-A ECMO) can lead to severe local complications. This study evaluated site-specific complications between percutaneous and surgical cannulation techniques for femoro-femoral V-A ECMO, focusing on site bleeding, infection, and limb ischemia.

Methods: We conducted a single-center retrospective cohort study of adult patients who received femoro-femoral V-A ECMO either by percutaneous or surgical technique at a tertiary center. Cannulation-site complications were assessed from cannulation to post-decannulation. Risk factors for site bleeding, infection, and limb ischemia within 90 days of cannulation were analyzed using logistic regression.

Results: Among 384 patients (22.4% female), 181 (47.1%) underwent percutaneous, and 203 (52.9%) underwent surgical cannulation. Percutaneous cannulation was associated with significantly fewer patients experiencing site bleeding (29.3% vs. 40.9%, p = 0.02) and infection (8.3% vs. 31.0%, p < 0.001), with no significant difference in limb ischemia (11.6% vs. 15.3%, p = 0.29). 90-day survival was similar between groups (43.6% vs. 49.8%, p = 0.81). Multivariable logistic regression identified surgical cannulation as an independent risk factor for site bleeding (OR 2.39, 95% CI 1.43-3.98; p < 0.001) and infection (OR 5.47; 95% CI 2.47-12.12; p < 0.001). Limb ischemia was not significantly associated with the cannulation technique but with two other modifiable factors at cannulation: absence of distal perfusion catheterization and larger arterial cannula size.

Conclusion: Percutaneous cannulation was associated with significantly fewer patients experiencing site bleeding and infection compared to surgical cannulation. Limb ischemia was not associated with the cannulation technique but was influenced by two other modifiable factors at cannulation: distal perfusion catheterization and arterial cannula size.

Background: Sex differences in outcomes of patients on left ventricular assist devices (LVAD) have been reported with conflicting results. Female hormonal status affects vascular integrity and cardiac remodeling. As menopausal transition is complex and individually variable, we used age as a surrogate for hormonal status and compared outcomes in younger and older women with age-matched men.

Methods: Data from 5.275 patients from the EUROMACS registry were screened. Women < 40 years (31.0 ± 6.3 years, n = 142, surrogate premenopausal) and > 60 years (65.5 ± 3.7 years, n = 256, surrogate postmenopausal) were included, while women aged 40-60 years were excluded to avoid misclassification during the perimenopausal transition. For comparison, 2138 age-matched males were included. The primary outcome was survival, with transplantation and weaning as competing risks. Secondary outcomes were defined as adverse events and length of intensive-care-unit stay.

Results: Young women were more likely to present in cardiogenic shock before LVAD implantation (INTERMACS level1-2: 65.6% vs. 45.4%, p = 0.022). Within four years, young women had higher rates of weaning, transplantation and survival (weaning:sHR 1.58, 95% CI 0.73-3.4, p = 0.248; transplant: sHR2.93, 95% CI 1.86-4.61, p < 0.001; survival:sHR 2.25, 95% CI 1.48-3.41; p = 0.001). Major adverse events were more frequent in older women (bleeding: RR2.53, 95%-CI 1.7-3.8, p < 0.001; infection: RR1.43, 95% CI 1.2-1.8, p < 0.001). Comparable differences were observed in age-matched males.

Conclusions: Outcomes differed between age groups, but not consistently between sexes within the same age group, suggesting age rather than sex or menopausal status driving outcome differences. These descriptive findings support equitable consideration of LVAD therapy irrespective of sex.

This manuscript synthesizes the most recent advances in machine perfusion (MP) presented at the 2025 International Liver Transplantation Society Congress in Singapore. We highlight how MP has matured into a transformative tool in liver transplantation, with growing evidence of improved graft viability, reduced complications, expanded donor utilization, and systemic impact on allocation and logistics. Special attention is given to recent innovations in translational bridges and real-world cost analyses that support broader clinical implementation.

Background: The Extracorporeal Life Support Organization recommends daily antithrombin monitoring and supplementation to achieve > 50%-80% activity during extracorporeal membrane oxygenation (ECMO). Evidence supporting this practice is uncertain, and whether it confers clinical benefit or harm is unclear.

Methods: This was a systematic review with meta-analysis to evaluate the safety and efficacy of antithrombin supplementation during ECMO. We systematically searched databases and registers for studies comparing patients on ECMO who received antithrombin supplementation to those who did not. Random effects meta-analysis was performed. Risk of bias was independently assessed by two investigators. A priori subgroup and sensitivity analyses were performed to explore reasons for heterogeneity.

Results: A total of 11 studies were identified. In the pooled meta-analysis, antithrombin supplementation resulted in no difference in bleeding events (OR 1.38, 95% CI, 0.88-2.17, p = 0.16), thrombotic events (OR 1.57, 95% CI, 0.84-2.90, p = 0.15), or mortality (OR 1.21, 95% CI, 0.81-1.81, p = 0.35) when compared to those who did not receive antithrombin. Subgroup analysis revealed no difference in bleeding events or mortality in pediatric or adult patients; however, pediatric patients that received antithrombin were more likely to experience a thrombotic event (OR 1.70, 95% CI, 1.51-1.91). Sensitivity analysis in only low risk of bias studies confirmed these findings.

Conclusions: Antithrombin supplementation was not associated with differences in mortality or hemostatic outcomes during ECMO support and may be associated with harm in pediatric patients on ECMO.

Objective: In cases of sepsis and an excessive inflammatory response, continuous renal replacement therapy (CRRT) has the potential to provide immunomodulation by removing cytokines and inflammatory mediators. This study aimed to evaluate the efficacy of the Oxiris filter, which has endotoxin and cytokine adsorption properties, in the pediatric population and compare it with conventional filters.

Method: This retrospective study examined 42 pediatric intensive care patients diagnosed with sepsis or multisystem inflammatory syndrome in children (MIS-C). The patients received CRRT with either Oxiris filters (n = 21) or conventional filters (n = 21). The study compared hemodynamic and laboratory parameters, as well as mortality.

Results: The two groups had similar baseline characteristics and disease severity scores (PRISM III, PELOD II, and OFI). Overall mortality rates were comparable between the Oxiris and conventional filter groups (52.4% vs. 57.1%; p = 0.757), whereas 28-day mortality was significantly lower in the Oxiris group (28.6% vs. 61.9%; p = 0.030). Within 24 h, both filters showed comparable improvements in VIS, heart rate, mean arterial pressure (MAP), lactate, bicarbonate, and albumin levels (all p > 0.05); no significant changes were observed in C-reactive protein (CRP) or procalcitonin levels. Subgroup analysis revealed a more pronounced VIS reduction (p = 0.013), less adequate acidosis correction (p = 0.022), and higher PELOD-II scores (p = 0.026) among non-survivors. Thrombocytopenia was the most common complication, with no difference between the two groups.

Conclusion: In critically ill pediatric patients, Oxiris and conventional filters produced comparable short-term hemodynamic, metabolic, and inflammatory effects during CRRT. While overall mortality did not differ between the groups, 28-day mortality was lower in the Oxiris cohort. Further multicenter, prospective research is warranted to confirm these findings and to identify specific pediatric subgroups that may benefit from Oxiris therapy.

Background: Left Ventricular Assist Devices, particularly Heart Mate 3 (HM3), have improved outcomes for advanced heart failure patients. Despite advancements, hemocompatibility-related adverse events (HRAEs) continue to pose significant challenges. Standard antithrombotic therapy combines vitamin K antagonists (VKAs) with aspirin, though the ARIES-HM3 trial showed aspirin avoidance from implantation reduces bleeding without increasing thrombotic events. Whether discontinuing aspirin in stable, long-term HM3 patients is safe remains unclear.

Methods: This retrospective single-center study included 44 HM3 recipients maintained on VKA plus low-dose aspirin who underwent aspirin discontinuation while clinically stable. HRAEs, neurological events, nonsurgical bleeding and pump thrombosis, were assessed during two 6-month intervals: pre- and post- aspirin withdrawal. Secondary endpoints included individual HRAE components and hemolysis markers (lactate dehydrogenase [LDH] and hemolysis index [HI]).

Results: Mean age at discontinuation was 59.6 ± 13.1 years, with median LVAD support duration of 952.5 days. HRAEs occurred in four patients (9.1%) before discontinuation versus three patients (6.8%) after (p = 1.00). Neurological events (2.3% in both periods) and pump thrombosis (2.3% in both periods) were rare. Bleeding declined from 7.0% to 2.3% (p = 0.63), with no gastrointestinal bleeding after aspirin discontinuation. LDH remained unchanged (220 vs. 218 U/L, p = 0.89), while HI rose (Median 3 vs. 5, p = 0.008) but stayed within normal range.

Conclusion: In long-term, stable HM3 recipients on VKA therapy, aspirin discontinuation did not increase HRAEs. Laboratory markers of hemolysis remained stable aside from a modest, clinically insignificant rise in HI. These findings extend randomized evidence supporting aspirin avoidance at implantation to patients with long-term HM3 support and suggest simplified antithrombotic regimens may be safe in selected HM3 patients. Larger multicenter studies with longer follow-up are warranted.