Journal of Artificial Organs最新文献

Since the COVID-19 pandemic of 2020-2023, extracorporeal membrane oxygenator (ECMO) has attracted considerable attention worldwide. It is expected that ECMO with long-term durability is put into practical use in order to prepare for next emerging infectious diseases and to facilitate manufacturing for novel medical devices. Polypropylene (PP) and polymethylpentene (PMP) capillary membranes are currently the mainstream for gas exchange membrane for ECMO. ECMO support days for COVID-19-related acute hypoxemic respiratory failure have been reported to be on average for 14 or 24 days. It is necessary to improve opposing functions such that promoting the permeation of oxygen and carbon dioxide and inhibiting the permeation of water vapor or plasma to develop sufficient durability for long-term use. For this purpose, accurately controlling the anisotropy of the pore structure of the entire cross section and functions of capillary membrane is significant. In this study, we focused on the cross-sectional ion-milling (CSIM) method, to precisely clarify the pore structure of the entire cross section of capillary membrane for ECMO, because there is less physical stress on the porous structure applied during the preparation of cross-sectional samples of porous capillary membranes. We attempted to observe the cross sections of commercially available PMP membranes using the CSIM method. As a result, we succeeded in fabricating fine-scale flat cross-sectional samples of PMP capillary membranes. The pore structures and the degree of anisotropy of the cross sections are quantitatively clarified. The achievements and the approaches of this study are being applied to the development of next-generation gas exchange membranes.

Neuron-specific-enolase is used as a marker of neurological prognosis after cardiopulmonary resuscitation. It is also present in red blood cells and platelets. It is not known whether hemolysis increases the values of neuron-specific-enolase enough to clinically affect its interpretation in critically ill patients who are to be introduced to veno-arterial extracorporeal oxygenation. In this study, we examined the relationships among neuron-specific-enolase and hemolysis indicators such as free hemoglobin and lactate dehydrogenase after the introduction of veno-arterial extracorporeal oxygenation. Of the 91 patients who underwent veno-arterial extracorporeal membrane oxygenation in our hospital from January 1, 2018, to February 24, 2021, 68 patients survived for more than 24 h. Of these, 14 patients who were categorized into the better cerebral performance categories (1-3) and 19 patients who were categorized into the poor neurological prognosis category (4) were included. After the introduction of veno-arterial extracorporeal membrane oxygenation, neuron-specific-enolase was markedly higher in the poor neurological prognosis group than in the good neurological prognosis group (41.6 vs. 92.0, p = 0.04). A significant positive correlation was revealed between neuron-specific-enolase and free hemoglobin in the good neurological prognosis group (rs = 0.643, p = 0.0131). A similar relationship was observed for lactate dehydrogenase and neuron-specific-enolase in both the conscious (rs = 0.737, p = 0.00263) and non-conscious groups (rs = 0.544, p = 0.0176). When neuron-specific-enolase is used as a marker for neuroprognostic evaluation, an abnormally high value is likely to indicate the lack of consciousness, whereas a lower elevation should be interpreted with caution, taking into account the effects of hemolysis.

Silk-elastin is an artificial protein that helps promote wound healing. The present study was performed to examine the effect of silk-elastin on burns using an animal model. Partial- and full-thickness burns were applied to the back of rats using a metal device. And the necrotic tissue was excised via surgical debridement and dressing materials were applied. Two groups, namely, the silk-elastin sponge and control groups, were established in the case of deep partial-thickness burns and full-thickness burns, respectively. Tissue samples from the partial-thickness burn model obtained at the 5th day and the 7th day after debridement were analyzed. The length of epithelization in the tissue sample and wound healing rate were evaluated on macro-photographs. And tissue samples from the full-thickness burn model obtained at the 7th day and 14th day after debridement were analyzed. The area of granulation, length of epithelization, and number of vessels in the tissue sample and wound healing rate were evaluated on macro-photographs. The silk-elastin group showed a better wound healing rate and superior epithelization and granulation and angiogenesis in comparison to control group. And our findings on day 14 in full-thickness burn suggest a potential difference in the quality of scars. Silk-elastin sponge can help promote burn wound healing after debridement. This new material can accelerate epithelization, granulation, and neoangiogenesis at the early stage after application with less dressing change. We believe that silk-elastin is a good material for use in topical burn therapy. And the new material may reduce scar forming after healed.

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.

During hemodialysis, proteins, such as albumin and globulin, are deposited on the dialysis membrane surface, causing fouling that affects solute removal and biocompatibility. This study aimed to measure the filtration coefficient as an index of dialysis membrane conditions in hemodialysis, pre-dilution online hemodiafiltration, and intermittent infusion hemodiafiltration modes using two different hemodiafiltration membranes ex vivo. The filtration coefficients of hemodiafiltration membranes in hemodialysis, pre-dilution online hemodiafiltration, and intermittent infusion hemodiafiltration modes were continuously measured for 123 min using 2 L bovine blood, which was adjusted with 32% hematocrit and 6.5 g/dL of total proteins. Polysulfone and cellulose triacetate were used as test membrane materials, and both membrane structures were asymmetric. The first fouling step was observed 20 s after filtration of both polysulfone and cellulose triacetate membranes in each mode. Thereafter, the filtration coefficient recovered in the pre-dilution online hemodiafiltration mode. However, it plateaued in the cellulose triacetate membrane and decreased in the polysulfone membrane. A flushing effect of the intermittent infusion hemodiafiltration mode was observed in both the cellulose triacetate and polysulfone membranes. The differences in fouling steps in each of the three modes-hemodialysis, pre-dilution online hemodiafiltration, and intermittent infusion hemodiafiltration-can be identified by continuously measuring filtration coefficient values.

Central vein stenosis (CVS) is a complication primarily affecting chronic hemodialysis patients, frequently resulting in vascular access dysfunction and decreased dialysis efficacy. While CVS has a variable mortality rate, its impact on dialysis access is profound, including arm edema, facial swelling, and venous hypertension. We describe the prevalence, clinical presentation, and treatment outcomes of CVS for vascular access in hemodialysis patients. We conducted a prospective observational study from July 2023 to June 2024, on patients undergoing maintenance hemodialysis (MHD) at a tertiary care center in South India who had CVS detected by CT Venography. Demographic information, comorbidity, access type, stenosis location, clinical presentation, treatment, and outcome data were collected and analyzed. Of the 152 patients on MHD, 20 (13.1%) had CVS. Of them, 7 patients were on tunneled catheter and 13 were on AVF. Arm edema (47%) was the most common symptom, followed by face swelling (29%) and prolonged bleeding (11%) from arteriovenous fistula post dialysis. The brachiocephalic vein (BCV) was the most common site of stenosis in 65% of patients. Angioplasty was performed in (N = 9) nine patients with a primary success rate of 66% and a six-month patency of 44.4%. In the remaining eleven (N = 11) four patients (20%) transitioned to CAPD, three (15%) had new access of which two had femoral catheter inserted and other one had new AVF creation done and two (10%) continued dialysis via same access. Mortality occurred in two patients (10%) due to pulmonary edema. The Prevalence of CVS in our study population was 13.1%. Six-month primary patency rate among those who underwent intervention was 44.4%. Vascular access had to be terminated in 55%.

The mechanical circulatory support (MCS) for pediatric patients with severe acute heart failure and poor pulmonary conditions is challenging. Herein, we report the first pediatric case of successfully treated by central Y-Y extra-corporeal membrane oxygenation (ECMO). A 10-year-old boy weighing 35 kg with a body surface area of 1.11 m² was transferred to our institution in cardiac arrest with ongoing cardiopulmonary resuscitation using intra-aortic balloon pump and peripheral ECMO inserted at the previous hospital. Then, MCS system was converted to central ECMO with left heart drainage due to severe pulmonary congestion and the anticipation of long-term MCS. After 3 days, we converted it to central Y-Y ECMO because of concern about intracavitary thrombus formation due to poor pulmonary conditions. After four more days, the pulmonary conditions were improved, and we converted the MCS system into left ventricular assist device (LVAD) system. He is awaiting the heart transplantation eligibility review in a stable condition. Central Y-Y ECMO system can be used as a bridge to decision also for a pediatric patient with acute severe heart failure and poor pulmonary conditions.

Brain-dead donor (DBD) is the basis for most organ transplants and has been the exclusive method of choice for heart transplantation (HTx). However, the severe shortage of donors has been the common problem worldwide, especially in Japan. Meanwhile, the number of donors after cardiac (circulatory) death (DCD) has increased rapidly in the last 10 years, especially in Europe, thus expanding the donor pool. This strategy has been introduced in HTx since 2014, starting in Australia and the United Kingdom, with acceptable results. In most DCD, organs are removed under withdrawal of life support (WLST), which is called controlled DCD (cDCD). In Japan, we should consider introducing cDCD to supplement DBD, which is compromised by the shortage of donors. In this setting of cDCD, ethical and regulatory arguments arise as to the definition of human death and how to deal with WLST in organ donation. From a regulatory point of view, cDCD has been misunderstood as requiring a separate legislative development, and to dispel this misconception is the important message of this report. The development of an ex vivo machine perfusion system is another issue to start cDCD HTx as well as other organs. This paper outlines the issues involved in the introduction of cDCD for heart transplantation in Japan.

Abel JJ, Rowntree LG and Turner BB (Baltimore Trio) proposed the concept of vividiffusion and developed a vividiffusion apparatus in 1912. In a 1914 paper, they laid out the most important rule of device design. We named this rule an ART law taken from the initials of the Baltimore Trio. The ART law means that a blood purification device with a shape that can secure as large a dialysis membrane area as possible for as small a volume of blood filling as possible will achieve high dialysis performance. Rather than using 8 mm inner diameter collodion tubes in the original vividiffusion apparatus, the solution to the device shape that fits this rule is to hold down the tube from both top and bottom to make it as flat as possible, or if it is a flat membrane, to bring two flat membranes as close together as possible, and in the case of tubes and hollow fibers, to make their inner diameter as small as possible of approximately 200 μm. In other words, the dialysis performance is greatly improved by narrowing the blood flow path. This is exactly the ART law, predicting the shape of today's blood purification devices.