Journal of Artificial Organs最新文献

Staphylococcus aureus is one of the main causative bacteria for polyurethane catheter and artificial graft infection. Recently, we developed a unique technique for coating diamond-like carbon (DLC) inside the luminal resin structure of polyurethane tubes. This study aimed to elucidate the infection-preventing effects of diamond-like carbon (DLC) coating on a polyurethane surface against S. aureus. We applied DLC to polyurethane tubes and rolled polyurethane sheets with our newly developed DLC coating technique for resin tubes. The DLC-coated and uncoated polyurethane surfaces were tested in smoothness, hydrophilicity, zeta-potential, and anti-bacterial properties against S. aureus (biofilm formation and bacterial attachment) by contact with bacterial fluids under static and flow conditions. The DLC-coated polyurethane surface was significantly smoother, more hydrophilic, and had a more negative zeta-potential than did the uncoated polyurethane surface. Upon exposure to bacterial fluid under both static and flow conditions, DLC-coated polyurethane exhibited significantly less biofilm formation than uncoated polyurethane, based on absorbance measurements. In addition, the adherence of S. aureus was significantly lower for DLC-coated polyurethane than for uncoated polyurethane under both conditions, based on scanning electron microscopy. These results show that applying DLC coating to the luminal resin of polyurethane tubes may impart antimicrobial effects against S. aureus to implantable medical polyurethane devices, such as vascular grafts and central venous catheters.

Patient-tailored silicone plug for HeartMate 3™ left ventricular assist device explantation in two successive males proceeded successfully. Given medical therapeutic advancements, FDA-approved plug systems designed by LVAD manufacturers themselves will be necessary for the near future to provide a safe and simple device explantation alternative that fulfills all regulatory standards.

Increased inflammatory biomarkers have been reported in prosthetic heart valve thrombosis (PHVT). Monocyte to HDL ratio (MHR) and albumin to CRP levels (CAR) are two biomarkers used widely for systemic inflammation but there is a lack of data on prosthetic heart valves. This study aimed to find out the potential predictive value of MHR and CAR for PHVT. Patients who had the diagnosis of mechanical mitral/aortic PHVT and normally functioning prosthesis were retrospectively analyzed. Laboratory data including complete blood count and biochemistry were recorded. Transesophageal echocardiography was performed to diagnose PHVT. The study included 118 patients with mechanical PHVT and 120 patients with normally functioning prosthesis. White blood count, monocyte levels, C-reactive protein, MHR and CAR were significantly higher whereas the lymphocyte, HDL and INR levels on admission were lower in patients with PHVT. Multivariate analysis showed that as well as inadequate anticoagulation, MHR, but not CAR, was found to be an independent predictor of thrombosis in patients with PHVT. Receiver operating characteristic curve analysis was performed to detect the best cut-off value of MHR in the prediction of thrombosis in patients with prosthetic valves. MHR level of > 12.8 measured on admission, yielded an AUC value of 0.791 [(CI 95% 0.733-0.848 p < 0.001) sensitivity 71%, specificity 70%]. Inadequate anticoagulation is the primary cause that leads to thrombosis in mechanical prosthetic valves. Increased MHR, but not CAR, was also shown to be an independent predictor of thrombosis in patients with mechanical mitral and aortic prosthetic valves.

Despite the high prevalence of sleep disturbance in the heart failure population, information about its consequence on daytime function in patients with left-ventricular assist devices (LVADs) is limited. This study examined the nighttime and daytime sleep patterns and changes from pre-implant to 6 months post-implant. This study included 32 LVAD patients. Demographics, nighttime and daytime sleep variables were collected pre-implant and at 1, 3, and 6 months post-implant. Wrist actigraphy and self-report questionnaires measured objective and subjective sleep, respectively. Objective nighttime sleep data were sleep efficiency (SE), sleep latency (SL), total sleep time (TST), wake after sleep onset (WASO), and sleep fragmentation (SF). Objective daytime sleep data were nap times. Self-reported Subjective Sleep Quality Scale (SSQS) and Stanford Sleepiness Scale (SSS) were subjective measures. Increased SF and WASO scores and decreased TST and SE scores were found pre-LVAD implant, indicative of poor sleep quality. TST, SE, naptime and SSQS scores were higher at 3 and 6 months post-implant compared to baseline. Decreases in TST and SF scores were observed at 3 and 6 months post-implant along with increases in SSS scores. Increasing SSS scores and decreasing overall scores from pre- and up to 6 months post-implant suggest improvement in daytime function. This study provides information on sleep-daytime function in the LVAD patient population. Improvements in daytime sleepiness do not imply "good" sleep quality, consistent with the extant knowledge in LVAD literature. Future investigations should elucidate the mechanism by which sleep-daytime function influences quality of life.

The evolution of hemodialysis membranes (dialyzer, artificial kidney) was remarkable, since Dow Chemical began manufacturing hollow fiber hemodialyzers in 1968, especially because it involved industrial chemistry, including polymer synthesis and membrane manufacturing process. The development of hemodialysis membranes has brought about the field of medical devices as a major industry. In addition to conventional electron microscopy, scanning probe microscopy (SPM), represented by atomic force microscopy (AFM), has been used in membrane science research on porous membranes for hemodialysis, and membrane science contributes greatly to the hemodialyzer industry. Practical studies of membrane porous structure-function relationship have evolved, and methods for analyzing membrane cross-sectional morphology were developed, such as the ion milling method, which was capable of cutting membrane cross sections on the order of molecular size to obtain smooth surface structures. Recently, following the global pandemic of SARS-CoV-2 infection, many studies on new membranes for extracorporeal membrane oxygenator have been promptly reported, which also utilize membrane science researches. Membrane science is playing a prominent role in membrane-based technologies such as separation and fabrication, for hemodialysis, membrane oxygenator, lithium ion battery separators, lithium recycling, and seawater desalination. These practical studies contribute to the global medical devices industry.

The St. Jude Medical Epic Supra valve is a porcine bioprosthesis designed for complete supraannular implantation. No report has shown the hemodynamic performance and clinical outcomes of aortic valve replacement with the Epic Supra valve for severe aortic stenosis in a Japanese cohort. We retrospectively evaluated 65 patients who underwent aortic valve replacement using the Epic Supra valve for aortic stenosis at our department between May, 2011 and October, 2016. The mean follow-up period was 68.7 ± 32.7 months, and the follow-up rate was 89.2%. The mean age was 76.8 ± 5.3 years. The 1-, 5-, and 8-year survival rates were 96.9%, 79.4%, and 60.3%, respectively. The rates of freedom from valve-related events were 96.6% and 81.9% at 5 and 8 years, respectively. Four patients were diagnosed with structural valve deterioration (SVD), and reintervention was performed in two patients. The rates of freedom from SVD were 98.2% and 83.3% at 5 and 8 years, respectively, and the mean time to diagnosis of SVD was 72.5 ± 25.3 months. The mean pressure gradient (MPG) was 16.8 ± 6.0 mmHg postoperatively, 17.5 ± 9.4 mmHg at 5 years, and 21.2 ± 12.4 mmHg at 8 years (p = 0.08). The effective orifice area index (EOAI) was 0.95 ± 0.2 cm2/m2 immediately after surgery, 0.96 ± 0.27 cm2/m2 at 5 years, and 0.84 ± 0.2 cm2/m2 at 8 years (p = 0.10). An increase in MPG and decrease in EOAI were also observed, which may be associated with SVD. Follow-up after 5 years is important to determine if there is an increase.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are strongly recommended in patients with heart failure, regardless of the presence of diabetes mellitus. A 74 year-old woman with a reduced left ventricular ejection fraction and diabetes mellitus (the types were unknown), receiving insulin and SGLT2 inhibitor, was hospitalized for altered consciousness with systemic hypotension. Upon admission, she was diagnosed with cardiogenic shock due to diabetic ketoacidosis. Intensive fluid resuscitation under Impella CP support successively improved her metabolic acidosis, preventing worsening pulmonary congestion by mechanically unloading the heart. After hemodynamic stabilization, she was diagnosed with type 1 diabetes mellitus for the first time. She was discharged on day 54 and was followed for 6 months without any recurrences. We must remain vigilant regarding the risk of diabetic ketoacidosis in patients using SGLT2 inhibitors, particularly those on insulin therapy or with diabetes mellitus of unknown types. Impella device shows promise as a circulatory support system in alleviating the left ventricle's workload and averting exacerbated pulmonary congestion, especially in cases where patients necessitate aggressive fluid replacement therapy, such as in the treatment of diabetic ketoacidosis concurrent with compromised cardiac function.

It is believed that a lower temperature setting of hypothermic circulatory arrest (HCA) in thoracic aortic surgery causes coagulopathy, resulting in excessive bleeding. However, experimental studies that eliminate clinical factors are lacking. The objective of this study is to investigate the influence of the temperature setting of HCA on coagulation in a pig model. Ten pigs were divided into the following two groups: moderate temperature at 28 °C (group M, n = 5) or lower temperature at 20 °C (group L, n = 5). Two hours of HCA during a total of 4 h of cardiopulmonary bypass (CPB) were performed. Blood samples were obtained at the beginning (T1) and the end (T2) of the surgery, and coagulation capability was analyzed through standard laboratory tests (SLTs) and rotational thromboelastometry (ROTEM). In SLTs, hemoglobin, fibrinogen, platelet count, prothrombin time, and activated partial thromboplastin time were analyzed. In ROTEM analyses, clotting time and clot formation time of EXTEM, maximum clot firmness (MCF), and maximum clot elasticity (MCE) of EXTEM and FIBTEM were analyzed. Fibrinogen decreased significantly in both groups (group M, p = 0.008; group L, p = 0.0175) at T2, and FIBTEM MCF and MCE also decreased at T2. There were no differences regarding changes in parameters of SLTs and ROTEM between groups. CPB decreases coagulation capacity, contributed by fibrinogen. However, a lower temperature setting of HCA at 20 °C for 2 h did not significantly affect coagulopathy compared to that of HCA at 28 °C after re-warming to 37 °C.

The shortage of organs for heart transplantation has created a need to explore the use of extended-criteria organs. We report the preliminary use of normothermic TransMedics Organ Care System-an ex vivo approach to preserve extended-criteria brain-dead donor hearts. This System maintains a normal temperature, provides continuous perfusion and oxygenation, reduces ischemic time, and enables additional viability assessment options. In a retrospective single-centre study conducted from April 2020 to March 2023, four extended criteria brain-dead donor hearts were perfused and monitored using the Organ Care System. Suitability for transplantation was assessed based on stable or decreasing lactate levels, along with appropriate perfusion parameters. The Organ Care for use of the Organ Care System were coronary artery disease, left ventricular hypertrophy, high-dose inotrope use in the donor, a downtime exceeding 20 min, and a left ventricular ejection fraction of 40-50%. Three out of the four donor hearts were transplanted, while one was discarded due to rising lactate concentration. The three recipients had a higher surgical risk profile for heart transplant. All showed normal cardiac function and no primary graft dysfunction postoperatively. At 2-3 years post-transplant, all recipients have a ventricular function of > 60%, with only one showing evidence of mild rejection. The Organ Care System enables the successful transplantation of marginal donor organs in high-risk recipients, showcasing the feasibility of recruiting donors with extended criteria. This technique is safe and promising, expanding the donor pool and addressing the organ shortage in heart transplantation in Hong Kong.

A simple and robust method for veno-venous extracorporeal membrane oxygenation (V-V ECMO) involves a drainage cannula into the inferior vena cava via the femoral vein (FV) and a reinfusion cannula into the right atrium (RA) via the internal jugular vein (IJV) (F-J configuration). However, with this method, the arterial oxygen (PaO₂) is said to remain below 100 mmHg.Since recently, in our ICU, to prevent drainage failure, we apply a modification from the commonly practiced F-J configuration by advancing the tip of the drainage cannula inserted via the FV into the superior vena cava (SVC) and crossing the reinfusion cannula inserted via the IJV in the RA (F(SVC)-J(RA) configuration). We experienced that this modification can be associated with unexpectedly high PaO₂ values, which here we investigated in detail.Veno-arteriovenous ECMO was induced in a 65-year-old male patient who suffered from repeated cardiac arrest due to acute respiratory distress syndrome. His chest X-ray images showed white-out after lung rest setting, consistent with near-absence of self-lung ventilation. Cardiac function recovered and the system was converted to F(SVC)-J(RA) configuration, after which both PaO₂ and partial pressure of pulmonary arterial oxygen values remained high above 200 mmHg. Transesophageal echocardiography could not detect right-to-left shunt, and more efficient drainage of the native venous return flow compared to common F-J configuration may explain the increased PaO₂.Although the F(SVC)-J(RA) configuration is a small modification of the F-J configuration, it seems to provide a revolutionary improvement in the ECMO field by combining robustness/simplicity with high PaO₂ values.