Journal of Artificial Organs最新文献

Caco-2 cells are derived from human colon cancer and have the ability to differentiate into human intestinal epithelial-like cells. The 2D in vitro intestinal model of Caco-2 cells cultured on a semi-permeable membrane is widely used in drug development and the evaluation of absorption functions. However, these intestinal models lack the structural characteristics of the small intestine in vivo, and the cell behavior is not properly controlled. Previous studies have reported that the microstructure of the villi and crypts on a small intestine-mimicking scaffold promotes Caco-2 differentiation; however, the effect of the nanostructure of the small intestine-mimicking scaffold on Caco-2 differentiation remains unclear. This study aimed to elucidate the effects of nanostructures on the small intestine mimetic scaffold in Caco-2 differentiation. We fabricated a decellularized small intestine in which the basement membrane nanostructure was altered through a subtractive process. Caco-2 cells were cultured on decellularized small intestine for 21 days, and the differentiation of Caco-2 cells was assessed. The microvillus density of Caco-2 cultured on decellularized small intestine that retained the unique nanostructure of small intestinal basement membrane was significantly higher than that of Caco-2 cultured on decellularized small intestine that did not retain the unique nanostructure of small intestinal basement membrane. This indicates that nanostructures specific to the basement membrane of the small intestine enhanced Caco-2 cell maturation.

End-of-life decision-making and the evolution of patient preferences over time remain insufficiently explored in destination therapy with left ventricular assist device (DT-LVAD) in Japan. This retrospective observational study analyzed standardized advance directives from DT-LVAD patients in Japan. The advance directives comprised (1) preferred end-of-life medical care, (2) designated surrogate decision-makers, and (3) personal life wishes. This study comprises two components: a cross-sectional analysis of all patients at the time of LVAD implantation, and a longitudinal analysis evaluating changes in advance directive preferences among patients who completed the 1-year follow-up assessment. This study included 27 patients who initially received DT-LVAD (median age 47 years, 21 men). At the time of LVAD implantation, approximately 30% of DT-LVAD patients preferred continued mechanical support, including LVAD, mechanical ventilator, and hemodialysis, until the end-of-life stage in a cross-sectional analysis. In addition, 56% preferred receiving end-of-life care at home. In a longitudinal analysis, patients remaining on DT-LVAD showed increased preference for "independence" and "end-of-life care at home" after 1 year of DT-LVAD, whereas their inclination toward invasive treatments decreased. In contrast, patients switched to BTT demonstrated lower inclination toward invasive therapies from the outset, with this tendency becoming more pronounced over time. This study demonstrates the changes in the end-of-life preferences of DT-LVAD patients in Japan. With the continuous increase in the number of DT-LVAD patients, further refinement of advance directive frameworks and the development of structured community-based support systems will be essential for optimizing end-of-life care among LVAD recipients.

To determine the optimal perfusion volume for the celiac artery (CA) and superior mesenteric artery (SMA) in a porcine model. Fifteen Yorkshire pigs (46.7 ± 5.2 kg) underwent selective CA and SMA perfusion using a roller pump at either 400 mL/min (G400, n = 5) or 800 mL/min (G800, n = 6). Hemodynamic parameters, blood gas analyses, and biochemical markers were evaluated over time (T1 to T5). The intestinal tissue was assessed for edema and histological damage. Portal vein SvO2 was lower in G400 (65.0 ± 30.2% at T2) compared to G800 (87.0 ± 5.2%), indicating reduced perfusion. Lactate levels were significantly higher in G400 (7.8 ± 2.3 mmol/L at T2) than in G800 (4.1 ± 2.1 mmol/L), suggesting increased anaerobic metabolism. Aspartate aminotransferase levels were elevated in G400, reflecting intestinal ischemia, whereas alanine aminotransferase levels remained stable. Histological analysis revealed mucosal desquamation in G400 but not in G800. No significant differences in intestinal edema were observed between groups. A selective perfusion volume of 800 mL/min for the CA and SMA maintains portal vein SvO2 and prevents mucosal injury, suggesting it approximates physiological blood flow. These findings indicate that increasing selective visceral perfusion during thoracoabdominal aortic surgery may reduce postoperative intestinal complications and improve patient outcomes.

Left ventricular assist device (LVAD) implantation is a treatment option for advanced heart failure. The relationship between smoking and perioperative outcomes in LVAD implantation remains inconclusive, as evidence has been limited to single-center studies. This study aimed to examine the association between smoking and in-hospital outcomes of LVAD implantation in a large-scale population-based analysis. Patients who underwent LVAD implantation were selected from National Inpatient Sample from Q4 2015-2021. Multivariable logistic regression was used to compare in-hospital outcomes between smokers and non-smokers, where demographics, socioeconomic status, primary payer status, hospital characteristics, comorbidities, and transfer/admission status were adjusted. There were 1346 (26.5%) smokers and 3737 (73.5%) non-smokers who underwent LVAD implantation. Smokers presented with a higher burden of comorbidities. After multivariable adjustment, smokers had lower in-hospital mortality (aOR 0.68, 95 CI 0.52-0.889, p < 0.01), MACE (aOR 0.74, 95 CI 0.554-0.987, p = 0.04), neurological complications (aOR 0.555, 95 CI 0.367-0.839, p = 0.01), stroke (aOR 0.508, 95 CI 0.311-0.832, p = 0.01), pericardial complications (aOR 0.705, 95 CI 0.545-0.913, p = 0.01), renal complications (aOR 0.691, 95 CI 0.595-0.801, p < 0.01), venous thromboembolism (aOR 0.523, 95 C = 0.295-0.929, p = 0.03), hemorrhage/hematoma (aOR 0.746, 95 CI 0.641-0.869, p < 0.01), and superficial wound complication (aOR 0.458, 95 CI 0.286-0.733, p < 0.01). Moreover, smokers had a shorter time from admission to operation (p = 0.02), shorter length of stay (p < 0.01), lower transfer out rate (p < 0.01), and lower hospital charge (p < 0.01). This study uncovered a "smoker's paradox" in LVAD implantation. These findings added to the long-standing observation of a "smoker's paradox" in cardiac surgery. However, the underlying reasons require further investigation.

Infection cases have been reported where Legionella spp. and NTM (non-tuberculous mycobacteria) increased due to the contamination of circulating water in cold/heated water supply systems for extracorporeal circulation used in cardiac surgery and ECMO (extracorporeal membrane oxygenation) for blood temperature regulation. The contaminated circulating water became aerosolized and may have been a source of infection. The internal structure of these systems is complex, making it difficult to clean and disinfect the inside of tanks and piping, posing a risk of becoming a breeding ground for bacteria. However, contamination and environmental exposure risks have not been clearly understood. Therefore, we conducted an experimental investigation to evaluate the potential spread of NTM from the circulating water to the surrounding environment, using Mycobacterium fortuitum as a test organism and confirmed that Mycobacterium was dispersed into the air during system operation and when opening the cover of the cold/heated water tank for water supply. It is urgent to establish methods to maintain effective cleaning and disinfection of cold/heated water supply systems for extracorporeal circulation and to implement operational improvements, such as enhancing the sealing of water tank covers, minimizing the opening of water tank covers during operation, and isolating the system in the operating environment.

To investigate the feasibility of regional oxygen saturation (rSO₂) monitoring for preventing acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) caused by cardiopulmonary bypass (CPB) in infants undergoing ventricular septal defect (VSD) closure. This study included 49 infants who underwent VSD closure between January 2012 and December 2023. Patients with preoperative pulmonary hypertension were excluded. rSO₂ of the head, abdomen, and thigh was monitored perioperatively. ALI/ARDS was defined as a PaO₂/FiO₂ ratio (P/F ratio) ≤ 300 upon pediatric intensive care unit (PICU) admission. The median age at surgery was 4 (interquartile range: 3-5) months, and the median weight was 6.03 (interquartile range: 5.30-6.78) kg. Five (10%) patients developed postoperative ALI/ARDS and had a longer PICU stay (8 vs 5 days, P < 0.001) and hospital stay (10 vs 5 days, P = 0.005). According to multiple regression analysis, thigh rSO₂ during CPB was a significant predictor of postoperative P/F ratio (β: 4.88, standard error: 1.99, P = 0.02). Receiver operating characteristic curve analysis showed that thigh rSO₂ during CPB (area under the curve: 0.87, P = 0.01) significantly predicted postoperative ALI/ARDS. The optimal cutoff value for thigh rSO₂ was 71%, with a sensitivity of 80% and specificity of 93%. Thigh rSO₂ monitoring during CPB may be effective for detecting ALI/ARDS in infants who underwent VSD closure. Maintaining rSO₂ levels above 71% might help prevent the onset of ALI/ARDS.

Purpose: Prolonged ECMO has become more common during the COVID-19 pandemic but is associated with high resource utilization and poor outcomes. This study aimed to identify predictors of prolonged ECMO and explore prognostic indicators in patients who underwent prolonged ECMO.

Methods: This multicenter retrospective study analyzed patients who underwent venovenous ECMO for severe COVID-19 at three high-volume ECMO centers in Japan from January 2020 to December 2021. Patients requiring ECMO for ≥ 21 days were classified as the prolonged ECMO group. The study was structured in four steps: [1] comparison of baseline characteristics between survivors and non-survivors [2], identification of pre-ECMO predictive factors for prolonged ECMO [3], determination of prognostic factors among prolonged ECMO patients, and [4] comparison with established prognostic scoring systems.

Results: Among 121 patients, 32 (26%) required prolonged ECMO. Lower positive end-expiratory pressure (PEEP) before ECMO was identified as an independent predictor of prolonged ECMO (P < 0.001), with an optimal cutoff of 12 cmH₂O (area under the curve [AUC]: 0.70). Among prolonged ECMO patients, the Sequential Organ Failure Assessment (SOFA) score on ECMO day 21 was the only independent predictor of in-hospital survival (P = 0.002), with an optimal cutoff value of 12 (AUC: 0.82). The SOFA score on day 21 outperformed established prognostic scoring systems.

Conclusion: Lower PEEP before ECMO is a predictor of prolonged ECMO. In patients undergoing prolonged ECMO, the SOFA score on day 21 is an independent predictor of survival. Continuous assessment of organ dysfunction during ECMO may enhance prognostic evaluation and support clinical decision-making.

Continuous Flow -Left Ventricular Assist Devices (CF-LVADs) remain the mainstay in end stage HFrEF patients with refractory Stage D HF. AF is common in patients supported on CF-LVADs, with a significantly increasing number developing new-onset AF post LVAD implantation. This review will summarize the effects of atrial fibrillation on LVAD physiology and its impact on outcomes. Literature search for this qualitative review was done using Google Scholar and PubMed. Only studies in adult human LVAD patients were included. The keywords used were atrial fibrillation in LVADs, effect of atrial fibrillation on functional mitral regurgitation /tricuspid regurgitation, effect on right ventricular failure, pump thrombosis and stroke and gender differences in outcomes.The main aspects addressed are effect on LVAD hemodynamics, the complexinteractions between low pulse pressure and atrial fibrillation leading to pump thrombosis and stroke , the role of atrial fibrillation in the initiation and progression ofright ventricular failure, impact on valvular regurgitation (Functional Mitral /TricuspidRegurgitation), utility of Cardiac Resynchronization Therapy post LVAD implant anduse of AI-driven technologies in risk factor identification to help identify novel risk factors important in predicting prognosis to improve outcomes. Use of AI technologies to identify novel risk factors for atrial fibrillation post LVADsurgery is warranted in the context of race, ethnicity and gender. Further studies areneeded to address optimal pacing strategies in LVAD patients with cardiac resynchronization therapy to institute guidelines for use of this therapy post LVAD implantation especially in the context of co-existing atrial fibrillation.