Journal of Artificial Organs最新文献

Online hemodiafiltration (OHDF) for renal replacement therapy has two modes: pre- (pre-OHDF) and post-dilution OHDF (post-OHDF). To elucidate the precise differences between the two modes, a clinical study was performed using the same polysulfone hemodiafilters in the same patients. Eight patients were treated with ABH^™-22PA for 6 weeks: 3 weeks of pre-OHDF (with substitution volumes of 24, 36, and 48 L) and 3 weeks of post-OHDF (6, 8, and 10 L). The reduction ratios of urea, uric acid (UA), creatinine (CRE), inorganic phosphorus (iP), beta-2-microglobulin (β₂-MG), and alpha-1-microglobulin (α₁-MG) were evaluated. The removal amounts of β₂-MG, α₁-MG, and albumin were also evaluated by analyzing the spent dialysis fluids. The types and numbers of adverse events (AEs) and device malfunctions were recorded. The reduction ratios of urea, UA, CRE, iP, and β₂-MG were comparable among all conditions, while that of α₁-MG tended to be slightly higher in post-OHDF than in pre-OHDF. The removal amounts of α₁-MG and albumin in pre-OHDF and post-OHDF were significantly greater with the maximum substitution volume than with the minimum volume. However, the selective removal indices, which were obtained by dividing the amount of α₁-MG removed by the albumin level, tended to be slightly higher in pre- than in post-OHDF. No device-related AEs or device malfunctions occurred in either mode. No significant differences in inflammatory responses, evaluated by high-sensitivity C-reactive protein and interleukin-6, were observed. This study provides removal performance and safety data regarding the application of ABH-22PA for pre- and post-OHDF.

Most combined peritoneal dialysis and hemodialysis therapies are used to compensate for the lack of dialysis volume and efficiency in pre-started peritoneal dialysis patients. The aim was to determine the effects on both peritoneal dialysis and residual renal function when proactively combined therapy is started at dialysis induction. This report was based on observation of 10 patients who initiated dialysis therapy with a combination of peritoneal and hemodialysis at induction, and the control group consisted of 24 patients with peritoneal monotherapy in a single dialysis center. The technical survival of peritoneal dialysis therapy and urinary volume and creatinine clearance as residual renal function were assessed. Technical survival of peritoneal dialysis during the 5-year observation period was much better in patients who started with proactive combination therapy than with peritoneal dialysis monotherapy. Between induction and 24 months later, median urinary volume (interquartile value) changed from 1500 (1100-1583) to 800 (545-1875) mL/day and from 1600 (1300-2150) to 1480 (115-1885) mL/day for peritoneal alone and for combination therapy, respectively. Creatinine clearance values changed from 7.0 (6.0-8.7) to 2.0 (1.0-3.0) mL/min for peritoneal alone and from 6.0 (4.0-7.3) to 3.0 (0.5-4.0) mL/min for combination therapy. Though some possible confounding factors, including selection bias, cannot be ruled out, this investigation suggests the benefit of proactive combination dialysis therapy on the sustainability of peritoneal dialysis and residual renal function.

We developed a new artificial placenta (AP) system consisting of a loop circuit configuration extracorporeal membrane oxygenation (ECMO) with a bridge circuit designed to be applied to the fetus in the form of an umbilical arterial-venous connection. We aimed to evaluate the feasibility of the AP system by performing a hydrodynamic simulation using a mechanical mock circulation system and fetal animal experiment. The effect of the working condition of the AP system on the fetal hemodynamics was evaluated by hydrodynamic simulation using a mechanical mock circulation system, assuming the weight of the fetus to be 2 kg. The AP system was introduced to two fetal goats at a gestational age of 135 days. The general conditions of the experimental animals were evaluated. The mock simulation showed that in an AP system with ECMO in the form of an umbilical arterial-venous connection in series, it could be difficult to maintain fetal hemodynamics when high ECMO flow was applied. The developed AP system could have high ECMO flow with less umbilical blood flow; however, the possibility of excessive load on the fetal right-sided heart should be noted. In the animal experiment, kid 1 (1.9 kg) was maintained on the AP system for 12 days and allowed to grow to term. In kid 2 (1.6 kg), the AP system could not be established because of the occlusion of the system by a thrombus. The developed AP system was feasible under both in vitro and in vivo conditions. Improvements in the AP system and management of the general fetal conditions are essential.

Patients with left ventricular assist devices (LVADs) receive anticoagulation to decrease the risk of thrombosis. Various circumstances require discontinuing anticoagulation in LVAD patients, but the risks entailed are not well defined. In a retrospective review of LVAD implantation procedures, we examined the effect of time off anticoagulation on thrombosis and mortality rates after implantation. An international normalized ratio ≤ 1.5 was used to screen for patients taken off anticoagulation. Patients were divided into three groups by the cumulative number of days off anticoagulation: no discontinuation, short-term discontinuation (< 30 days), and long-term discontinuation (≥ 30 days). Rates of ischemic stroke, pump thrombosis, and mortality were compared among groups. Of 245 patients who underwent LVAD implantation during the study, 70 (28.6%) were off anticoagulation during follow-up: 37 (15.1%) had short-term discontinuation (median, 11 days), and 33 (13.5%) had long-term discontinuation (median, 124 days). Patients with long-term discontinuation had a higher rate of ischemic stroke (adjusted hazard ratio 8.5, p = 0.001) and death (adjusted hazard ratio 3.9, p = 0.001). The three groups did not differ in pump thrombosis rate. We conclude that after LVAD implantation, discontinuing anticoagulation for ≥ 30 days is independently associated with an increased risk of ischemic stroke and death.

The distribution volume of uric acid is affected by the amount of extracellular water (ECW), while urea distribution volume can be considered as total body water (TBW). Thus, the ratio of distribution volumes of uric acid and urea can be paralleled to and be considered as the proxy of ECW/TBW. A total of 108 patients at our facility was included. The uric acid and urea distribution volume ratio (UUVdR) calculated from the single-pool model, which was measured within 1 month of the time when the bioimpedance index was measured. ECW/TBW at the end of the HD session was measured by InBody S10. We investigated the association between the UUVdR and the ECW/TBW values and the factors affecting the residuals of the regression equation. We also evaluated the predictive ability of overhydration or dehydration in randomly selected two groups, i.e., the training group and the validation group. ECW/TBW correlated highly with UUVdR. Multivariate analysis demonstrated that only creatinine and ECW/TBW were significantly associated with regression residuals. The cutoff values of UUVdR for overhydration and dehydration were 0.666 and 0.579, respectively, in the training group. Their AUC were 0.872 and 0.898, respectively. The sensitivity and specificity values in the validation group were 0.571 and 0.868 for overhydration, and 0.444 and 0.953 for dehydration, respectively. UUVdR might be a proxy of hydration status in hemodialysis patients. It may be possible to predict hydration status without dedicated devices in the epidemiological study.

In recent years, due to the increase in diseases that require organ/tissue transplantation and the limited donor, on the other hand, patients have lost hope of recovery and organ transplantation. Regenerative medicine is one of the new sciences that promises a bright future for these patients by providing solutions to repair, improve function, and replace tissue. One of the technologies used in regenerative medicine is three-dimensional (3D) bioprinters. Bioprinting is a new strategy that is the basis for starting a global revolution in the field of medical sciences and has attracted much attention. 3D bioprinters use a combination of advanced biology and cell science, computer science, and materials science to create complex bio-hybrid structures for various applications. The capacity to use this technology can be demonstrated in regenerative medicine to make various connective tissues, such as skin, cartilage, and bone. One of the essential parts of a 3D bioprinter is the bio-ink. Bio-ink is a combination of biologically active molecules, cells, and biomaterials that make the printed product. In this review, we examine the main bioprinting strategies, such as inkjet printing, laser, and extrusion-based bioprinting, as well as some of their applications.

Although veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used to aid myocardial recovery in patients with postcardiotomy cardiogenic shock (PCCS), it has been associated with adverse effects. The combined use of VA-ECMO and Impella (ECPELLA) for PCCS, however, has been reported to be efficacious with few reports of thromboembolic events. We present a case of aortic thrombosis with visceral malperfusion during ECPELLA management for PCCS. We performed the Bentall procedure, mitral valve repair, tricuspid annuloplasty, and coronary artery bypass graft on a 73-year-old man admitted with congestive heart failure caused by annuloaortic ectasia, along with severe aortic and mitral regurgitation. VA-ECMO and Impella were required, since the cardiopulmonary bypass weaning was difficult. Impella was removed on postoperative day 4. On postoperative days 5 and 6, laboratory data showed worsening renal dysfunction, lactate levels, and acidosis. Contrast-enhanced computed tomography showed thrombosis in the celiac and superior mesenteric arteries. Aortic thrombectomy was performed. Hyperkalemia, caused by a reperfusion injury, resulted in ventricular fibrillation. Continuous hemodiafiltration improved the hyperkalemia. However, irreversible acidosis progressed, and the VA-ECMO flow rate could not be sustained. On postoperative day 7, the patient died. Perioperative use of Impella for PCCS may be effective in improving postoperative cardiac function. When sudden organ failure is observed after surgery, it is necessary to not only keep the exacerbation of cardiogenic shock in mind, but also the possibility of thrombosis.

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a reliable and effective extracorporeal life support during lung transplantation (LTx). However, the clinical benefit of delayed VV-ECMO weaning remains unclear. The current study aims to investigate whether delayed weaning of VV-ECMO is more beneficial to the rehabilitation for lung transplant patients. Patients who underwent LTx with VV-ECMO between January 2017 and January 2019 were included. Enrollment of patients was suitable for weaning off ECMO immediately after surgery. Randomization was performed in the operating room. Postoperative outcomes were compared between the two groups. Besides, univariate and multivariable logistic regressions were performed to estimate risk of postoperative complications. Compared to VV-ECMO weaning immediately after LTx, delayed weaning was associated with shorter hospital length of stay (days, 31 vs. 46; P < 0.05), lower incidence of noninvasive ventilation (4.3% vs. 24.4%; P < 0.05), primary graft dysfunction (PGD) (6.4% vs. 29.3%; P < 0.05), atrial fibrillation (AF) (4.3% vs. 22%, P < 0.05), and respiratory failure (4.3% vs. 19.5%; P < 0.05). Multivariable logistic regressions revealed that VV-ECMO weaning after LTx was independently correlated with increased risk of developing PGD [odds ratio (OR), 5.97, 95% CI 1.16-30.74], AF (OR, 6.87, 95% CI 1.66-28.47) and respiratory failure (OR, 6.02, 95% CI 1.12-32.49) by comparison of delayed VV-ECMO weaning. Patients with delayed VV-ECMO weaning are associated with lower complications and short hospital length of stay, while it relates to longer mechanical ventilation. These findings suggest that delayed VV-ECMO after LTx can facilitate rehabilitation.

Purpose: Fulminant myocarditis presents as acute severe heart failure and requires mechanical cardiocirculatory support. Left-ventricular (LV) decompression is necessary for the successful recovery of these patients. This retrospective study aimed to evaluate the functional outcomes of providing central extracorporeal membrane oxygenation (ECMO) with LV decompression for the treatment of refractory fulminant myocarditis.

Methods: Between January 2015 and February 2021, seven consecutive fulminant myocarditis patients (mean age: 41.1 ± 26.1 years) received central ECMO support with transapical LV decompression, with an 18 French cannula integrated into the ECMO circuit in a Y-fashion. The baseline characteristics and postoperative outcomes of the patients were collected.

Results: On admission, all patients received prior peripheral ECMO, and 85.7% (6/7) of patients received prior intra-aortic balloon pumping. However, all patients had refractory cardiogenic shock that failed prior to decompression. Six patients recovered successfully after a mean ECMO support of 20.0 ± 11.5 days and five patients had no recurrence of cardiac decompensation. The mean ICU and mean hospital stays were 36.7 ± 23.5 days and 60.6 ± 24.9 days, respectively. Hospital mortality was 28.6% (2/7). Two patients died due to sepsis and stroke during hospitalization.

Conclusions: Central ECMO with an LV vent was effective for fulminant myocarditis refractory to percutaneous cardiopulmonary support therapy and other therapies.