Journal of Artificial Organs最新文献

This study was conducted methodologically to determine the reliability and the validity of the Turkish version of the hemodialysis self-management scale in hemodialysis patients in Turkey. The study was conducted with 200 patients who received hemodialysis treatment between October 2022 and April 2023. Data were collected using a Patient Information Form and the Hemodialysis Self-Management Instrument. To test the reliability of the scale, the internal consistency coefficient Cronbach's Alpha, McDonald Omega, and test-retest reliability coefficients were calculated. Confirmatory factor analysis was performed to evaluate the validity. Unlike the original version, the scale consisted of 11 items and 4 subscales and showed an acceptable fit. The Cronbach alpha coefficient was 0.89; the McDonald Omega coefficient was 0.90. The hemodialysis self-management instrument is a reliable and valid scale in Turkey.

Using autologous orthotopic liver transplantation (AOLT) model in rats, the effect of lipid reactive oxygen species (L-ROS) inhibitor Ferrostain-1 on ferroptosis signal pathway was observed to determine whether ferroptosis occurred in rat liver injury after cold ischemia-reperfusion (I/R). Thirty-two healthy adult SPF male SD rats, 8 ~ 10 weeks old, weight 240 ~ 260 g, were divided into four groups by the method of random number table (n = 8): sham group, I/R group, I/R + Fer-1 group, I/R + DFO group. In the I/R + Fer-1 group, ferristatin-1(5 mg /kg) was intraperitoneally injected 30 min before surgery; in the I/R + DFO group, DFO 100 mg/kg was injected intraperitoneally 1 h before operation and 12 h after operation. Blood samples were taken from the inferior hepatic vena cava 24 h after reperfusion. After anesthesia, the rats were killed and part of their liver tissue was removed. The pathological changes of liver tissue sections were observed under a high-power microscope, and the liver injury was evaluated. Serum malondialdehyde (MDA) and serum levels of ALT, AST and IL-6 were determined by the ELISA method, Reduced glutathione (GSH), glutathione peroxidase 4 (GPX4), MDA, Fe2 + and superoxide dismutase (SOD) were determined in the liver tissue. Compared with the sham group, the serum levels of the IL-6,MDA, AST and ALT in I/R group were obviously higher (P < 0.05); The levels of MDA and Fe²⁺ in liver tissue were significantly increased (P < 0.05).The levels of SOD, GSH and GPX4 in liver tissue were decreased. The levels of serum MDA, IL-6, AST, and ALT in the I/R + Fer-1 and I/R + DFO groups were significantly lower than those in the I/R group at 24 h after reperfusion. In the I/R + Fer-1 group, the level of MDA in liver tissue decreased significantly, while the level of SOD, GSH and GPX4 in intestinal tissue increased (P < 0.05). In The I/R + DFO group, the levels of MDA and Fe²⁺ in liver tissue decreased significantly, while the level of SOD in intestinal tissue increased (P < 0.05). Ferroptosis is involved in pathophysiological process of liver injury after cold ischemia-reperfusion in AOLT rats.

This case report details a rare instance of total reversal of the pulmonary circulation (RPC) in a 56-year-old male patient on veno-arterial extracorporeal membrane oxygenation (V-A ECMO) during emergency cardiopulmonary resuscitation (eCPR) following a myocardial infarction and cardiac arrest. Previously unrecognized aortic and mitral valve regurgitations, along with V-A ECMO flow, resulted in severe pulmonary edema. We describe how pulmonary artery cannulation and modifying the ECMO circuit to veno-pulmonary arterial-arterial (VPa-A) ECMO successfully alleviated the severe pulmonary edema but may have caused reversal of the pulmonary circulation (RPC). To our knowledge, this is the first reported case of this phenomenon in a human.

We examined the number of patients abandoning cardiac replacement therapy due to the inability to secure a designated caregiver. At Osaka University Hospital Heart Center, when we receive a consultation for a patient with severe heart failure from another hospital, a heart failure team makes a visit to the referring hospital as soon as possible. We retrospectively analyzed this hospital-visit database. We received 199 severe heart failure consultations from 2016-2023. Issues identified during hospital visits included age ≥ 65 years (8%), inability to confirm the patient's intention (8.5%), and explicit refusal of therapy (2.5%). Medical problems included multiple organ failure (18.1%), obesity (13.1%), diabetes (9.5%), malignancy (5.5%), chronic dialysis (1.0%), and other systemic diseases (12.6%). Adherence problems included poor medication compliance (3.5%), history of heavy drinking (2.5%), and smoking (2.0%). Social problems included inadequate family support in 16.1% of patients. Of the 199 patients, 95 (48.0%) proceeded to a heart transplant and LVAD indication review meeting at Osaka University Hospital. The remaining 104 patients (52.0%) did not proceed to the meeting. Reasons included improvement of heart failure with conservative treatment in 37 cases (35.6%), death before discussion in 21 cases (20.2%), medical contraindications in 18 cases (18.3%), lack of caregivers in 18 cases (18.3%; 9.5% of 199 cases), and patient refusal in 5 cases (4.8%). Approximately 10% of patients consulted at Osaka University Hospital Heart Center for severe heart failure abandoned cardiac replacement therapy due to the lack of caregivers.

The mortality rate in patients with heart failure complicated by cardiogenic shock following acute myocardial infarction (AMI) remains high, prompting research on mechanical circulatory support. Improved mortality rates have been reported with the early introduction of EcMELLA (Impella combined with extracorporeal membrane oxygenation, ECMO). However, clear indications for this treatment have not been established, given the associated risks and limitations related to access routes. Left ventricular thrombosis is traditionally considered a contraindication for Impella use. A 74-year-old man without specific medical history or coronary risk factors was diagnosed with Forrester IV heart failure due to cardiogenic shock complicated by AMI and left ventricular thrombosis. The patient underwent emergency coronary artery bypass surgery, intracardiac thrombus removal, and Dor surgery. Following cardiopulmonary bypass, ongoing heart failure was observed, necessitating the implementation of EcMELLA for circulatory support. Preoperative computed tomography showed that the bilateral subclavian arteries were too narrow (< 7 mm) and anatomically unsuitable for traditional access methods. Thus, we introduced a single-access EcMELLA 5.5, through which the Impella was introduced and veno-arterial-ECMO blood was delivered from a single artificial vessel anastomosed to the brachiocephalic artery. The patient was weaned off veno-arterial-ECMO and extubated on postoperative day 3. By postoperative day 14, improved cardiac function allowed for Impella removal. The patient was discharged on postoperative day 31 with improved ambulation; thereafter, the patient returned to work. Thus, the single-access EcMELLA5.5 treatment strategy combined with Dor procedure was effective in left ventricular thrombosis in patients with heart failure with cardiogenic shock complicated by AMI.

Hemolysis is the most important issue to consider in the design and optimization of blood-contacting devices. Although the use of Computational Fluid Dynamics (CFD) in hemolysis prediction studies provides convenience and has promising potential, it is an extremely challenging process. Hemolysis predictions with CFD depend on the mesh, implementation method, coefficient set, and scalar-shear-stress model. To this end, an attempt was made to find the combination that would provide the most accurate result in hemolysis prediction with the commonly cited power-law based hemolysis model. In the hemolysis predictions conducted using CFD on the Food and Drug Administration (FDA) benchmark blood pump, 3 different scalar-shear-stress models, and 5 different coefficient sets with the power-law based hemolysis model were used. Also, a mesh independence test based on hemolysis and pressure head was performed. The pressure head results of CFD simulations were compared with published pressure head of the FDA benchmark blood pump and a good agreement was observed. In addition, results of CFD-hemolysis predictions which are conducted with scalar-shear-stress model and coefficient set combinations were compared with experimental hemolysis data at three operating conditions such as 6-7 L/min flow rates at 3500 rpm rotational speeds and 6 L/min at 2500 rpm. One of the combinations of the scalar-shear-stress model and the coefficient set was found to be within the error limits of the experimental measurements, while all other combinations overestimated hemolysis.

Left ventricular assist devices (LVADs) are implanted in patients with heart failure to support cardiac circulation. However, no standardized methods have been established for LVAD driveline exit site management for the prevention of infections. Therefore, this study evaluated the efficacy of modified driveline management compared with that of conventional driveline management. We retrospectively assessed the outcomes of 262 patients who underwent continuous-flow LVAD implantation between January 2005 and March 2023 at Osaka University in Japan. In conventional driveline management, an LVAD driveline penetrates the skin along the body surface and is fixed near the penetration site (n = 224). In contrast, in our modified fixation method, the LVAD driveline vertically penetrates the skin to prevent ischemia at the driveline exit site and is fixed at a distant abdominal site to prevent the movement of the driveline exit site due to body movement (n = 38). The rates of freedom from LVAD driveline infection in patients with conventional driveline management were 86, 75, and 63% at 1, 2, and 3 years after LVAD implantation, respectively. The rate of freedom from LVAD driveline infection in patients managed by the modified fixation method was 91% at 1, 2, as well as 3 years after LVAD implantation. The freedom rates from LVAD driveline infection in the patients with modified fixation method was lower than in the patients with the conventional method (p = 0.04). Our study revealed that the modified fixation method may offer the possibility for preventing LVAD driveline infection.

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a rescue therapy for severe respiratory failure in which conventional mechanical ventilation therapy is unsuccessful. Hemolysis during VV-ECMO support arises from multiple factors associated with organ damage and poor outcomes. Therefore, close and prompt monitoring is needed. Hemolytic uremic syndrome (HUS) is characterized by hemolysis, acute renal failure, and thrombocytopenia. Hemolytic features of the disease may complicate VV-ECMO management. A 26-year-old man with a history of cerebral palsy underwent VV-ECMO for acute respiratory distress syndrome (ARDS) due to septic shock caused by bacterial translocation during treatment for HUS. He showed features of hemolysis, with elevated lactate dehydrogenase (LDH), fragmented red blood cells, and low haptoglobin levels. Plasma free hemoglobin was measured daily throughout the whole course of ECMO with levels higher than 10 mg/dL but not exceeding 50 mg/dL. The extracorporeal membrane oxygenation (ECMO) circuit pressures were carefully monitored to ensure the pump generated no excessive negative pressure. The patient was weaned off ECMO on the eleventh day. There have been several cases of VA-ECMO in patients with HUS; however, there is limited literature on VV-ECMO. As the days on VV-ECMO tend to be longer than those on VA-ECMO, features of hemolysis may complicate management. Although HUS did not directly influence the clinical course in the present case, features of hemolysis were continuously observed. This case highlighted the importance of standard ECMO monitoring, especially daily measurement of plasma free hemoglobin.

Human body constitutes unique biological system containing specific fluid mechanics and biomechanics. Traditional cell culture techniques of 2D and 3D do not recapitulate these specific natures of the human system. In addition, they lack the spatiotemporal conditions of representing the cells. Moreover, they do not enable the study of cell-cell interactions in multiple cell culture platforms. Therefore, establishing biological system of dynamic cell culture was of great interest. Organs on chips systems were fabricated proving their concept to mimic specific organs functions. Therefore, it paves the way for validating new drugs and establishes mechanisms of emerging diseases. It has played a key role in validating suitable vaccines for Coronavirus disease (COVID-19). Herein, the concept of organs on chips, fabrication methodology and their applications are discussed.