International Journal of Artificial Organs最新文献

Introduction: Intra-dialytic hypotension (IDH) remains the commonest problem associated with routine haemodialysis treatments. Fluid shifts from intracellular(ICW) and extracellular(ECW) compartments to refill plasma volume during haemodialysis with ultrafiltration.

Methods: We studied the effect of relative changes in ICW and ECW indifferent body segments using multifrequency segmental bioimpedance during haemodialysis and IDH episodes.

Results: Of 42 haemodialysis patients,16 patients (38.1%) developed IDH within the first hour of dialysis. Patients with and without early IDH were well-matched for demographics and starting bioimpedance measurements. However, after 60 min, the relative change in in ECW/ICW ratio between the non-fistula arm and leg was significantly different for the early IDH group median -1.07 (-3.33 to 0.8) versus 0.61 (-0.78 to 1.8), p < 0.05, whereas there no differences in ultrafiltration rate, relative blood volume monitoring or on-line clearance.

Conclusion: Monitoring serial changes in fluid status in different body compartments with bioimpedance may potentially prevent IDH in the future.

Background: Donation after brain death (DBD) serves as the primary source for liver transplantation. However, livers obtained through DBD often incur damage due to unstable hemodynamics, potentially impacting transplantation outcomes. Extracorporeal Membrane Oxygenation (ECMO) emerges as an optimal technique for donor liver retrieval and has found application in clinical settings. Despite its clinical implementation, the precise mechanisms through which ECMO enhances liver functions remain elusive. This study aims to investigate the mechanisms underlying how ECMO ameliorates liver function in brain-dead donors.

Methods: We randomly assigned 18 male Sprague-Dawley (SD) rats (350 ± 50 g) into three groups: Con (n = 6), DBD-assisted drug (n = 6), and DBD-assisted ECMO (n = 6). After 3 h of ECMO, the rats were sacrificed. We assessed and compared changes in heart rate, blood pressure, cumulative liver damage (evaluated through HE and TUNEL staining), serum levels of AST and ALT, alterations in serum oxidative stress factors (MDA, H2O2, SOD, and 8-OHdG), and serum concentrations of related inflammatory factors (interleukin [IL]-1β, IL-6, IL-8, and TNF-α) among rats in the Con, DBD-assisted drug, and DBD-assisted ECMO groups. Subsequently, we established a rat orthotopic liver transplantation (OLT) model and transplanted livers obtained through the aforementioned methods. The post-transplantation status of the livers was observed.

Results: After 3 h of brain death, liver injury worsened, accompanied by a significant increase in serum transaminases, inflammatory responses, oxidative stress, and TUNEL staining. Strikingly, ECMO not only stabilized hemodynamics after DBD but also mitigated liver damage, leading to an alleviated status post liver transplantation.

Conclusions: ECMO stabilizes hemodynamics, attenuates inflammatory responses and oxidative stress, thereby enhancing the quality of liver grafts for transplantation.

Hepatopulmonary syndrome (HPS) poses a significant challenge in liver transplant patients, affecting between 10% and 30% of candidates. Historically, HPS was considered a contraindication for liver transplantation due to its association with high mortality rates. However, recent studies have shown improvements in pulmonary function post-transplant, leading to the inclusion of these patients as candidates. Despite this progress, approximately one-fifth of liver transplant recipients develop severe postoperative hypoxia, further complicating their clinical course and contributing to increased mortality. The management of post-transplant HPS involves various strategies, including extracorporeal membrane oxygenation (ECMO), although its use remains infrequently reported. Theoretical models suggest that oxygenation typically improves within 10 days post-transplant, while resolution of HPS may take 6-12 months, making ECMO an attractive possibility as a bridge to recovery in this population. We present a case were ECMO was used in this context.

Background: The optimal anticoagulation regimen for continuous renal replacement therapy (CRRT) in liver failure (LF) patients without increased bleeding risk remains controversial. Therefore, we conducted a monocentric retrospective study to evaluate the efficacy and safety of the regional citrate anticoagulation (RCA) versus low molecular weight heparin (LMWH) anticoagulation for CRRT in LF without increased bleeding risk.

Method: According to the anticoagulation strategy for CRRT, patients were divided into the RCA and LMWH-anticoagulation groups. The evaluated endpoints were patient survival, filter lifespan, bleeding, citrate accumulation, and totCa/ionCa ratio.

Result: Totally 167 and 164 filters were used in the RCA and LMWH group, respectively. The median filter lifespan was significantly longer in the RCA group (34 h (IQR = 24-54) versus 24 h (IQR = 18-45.5) [95%CI, 24.5-33]; p < 0.001). The 4-week mortality rate was significantly higher in the LMWH-anticoagulation group (71 (57.72%) vs 53 (40.46%); p = 0.006). After adjusted the important parameters in the multivariate COX regression model, the mortality risk was significantly reduced in the RCA group (HR = 0.668 [95%CI, 0.468-0.955]; p = 0.027). In the LMWH group, 30 bleeding episodes (24,19%) were observed, whereas only 7 (5.34%) occurred in the RCA group (p < 0.001). Two patients (1.5%) in the RCA group occurred citrate accumulation.

Conclusions: In LF patients without increased bleeding risk who underwent CRRT, RCA significantly extended the filter lifespan and improved patient survival rate. There was no significant difference in the rate of adverse events between the two groups.

Background: Fontan procedure, the standard surgical palliation to treat children with single ventricular defects, causes systemic complications over years due to lack of pumping at cavopulmonary junction. A device developed specifically for cavopulmonary support is thus considered, while current commercial ventricular assist devices (VAD) induce high shear rates to blood, and have issues with paediatric suitability.

Aim: To demonstrate the feasibility of a small, valveless, non-invasive to blood and pulsatile rotary pump, which integrates impedance and peristaltic effects.

Methods: A prototype pump was designed and fabricated in-house without any effort to optimise its specification. It was then tested in vitro, in terms of effect of pumping frequency, background pressure differences and pump size on output performance.

Results: Net flow rate (NFR) and maximum pressure head delivery are both reasonably linearly dependent on pumping frequency within normal physiological range. Positive linearity is also observed between NFR and the extent of asymmetric pumping. The device regulates NFR in favourable pressure head difference and overcomes significant adverse pressure head difference. Additionally, performance is shown to be insensitive to device size.

Conclusions: The feasibility of the novel rotary pump integrating impedance and peristaltic effects is demonstrated to perform in normal physiological conditions without any optimisation effort. It provides promising results for possible future paediatric cavopulmonary support and warrants further investigation of miniaturisation and possible haemolysis.

Background: The continuity of arteriovenous fistula (AVF) patency is essential for effective hemodialysis. In the present study, we aimed to investigate the relationship between AVF patency and atherogenic index of plasma (AIP) in patients with native proximal upper-extremity AVF.

Methods: A total of 143 patients with native proximal upper-extremity AVF created in our clinic between January 2014 and April 2022 were analyzed retrospectively. Those with at least 24 months of follow-up and intact AVF were defined as "Group 1" (n = 97), and those with AVF thrombosis were defined as "Group 2" (n = 46).

Results: The primary patency rates of the patient groups included in the study were found to be 88.1% at 6th month, 79% at 12th month, and 67.8% at 24th month. The mean AIP values that were calculated in Group 2 were found to be statistically significantly higher than the mean value calculated in Group 1 (0.30 ± 0.12 vs 0.20 ± 0.10, p < 0.001). In a multivariate logistic regression analysis made to identify the predictors of proximal upper-extremity AVF thrombosis development, total cholesterol (OR [odds ratio] = 2.259, 95% CI [confidence interval] = 1.468-3.475, p < 0.001), and triglyceride (OR = 13.777, 95% CI = 3.740-50.750, p < 0.001) were identified as independent predictors.

Conclusion: A significant relationship was detected in the analyses between the easily calculated AIP values and the development of AVF thrombosis. The AIP is a remarkable preoperative parameter regarding proximal upper-extremity AVF patency.

Objective: To construct a prediction model of coagulation in the extracorporeal circulation circuit during hemodialysis with regional citrate anticoagulant(RCA) conditions.

Methods: This was a single-center, retrospective study. The clinical data of patients who received hemodialysis with RCA from February 2021 to March 2022 were collected. The risk predictors of coagulation in the extracorporeal circulation circuit were screened by LASSO regression. On this basis, we used multivariate logistic regression analysis to establish a nomogram prediction model.

Results: A total of 98 patients received RCA hemodialysis for 362 times. Among them, 155 treatments with complete data were included in the study. Among the 155 treatments, coagulation of the extracorporeal circulation circuit occurred 12 times. The use of arteriovenous fistulas(AVF), the venous pressure at 4 h after hemodialysis initiation, blood flow velocity, dialyzer manufacturer, Systemic iCa²⁺ at 1 h after hemodialysis initiation, plasma albumin level, and plasma d-dimer level were influencing factors of coagulation in the extracorporeal circuit during hemodialysis with RCA (p < 0.05). A nomogram model was made out of the above indicators. The area under the receiver operating characteristic (ROC) curve for predicting coagulation in the circuit was 0.967 (95% CI: 0.935-0.998). The internal validation result of the memory testing (bootstrap method) showed that the area under the ROC curve was 0.967 (95% CI: 0.918-0.991).

Conclusion: The nomogram model has good discrimination and calibration and can intuitively and succinctly predict the risk of coagulation in the extracorporeal circulation circuit during hemodialysis with RCA.

Aim: The optimal preparation conditions of Salmon decalcified bone matrix (S-DBM) were explored, and the properties of S-DBM bone particles and bone powder were studied respectively. The therapeutic effect of S-DBM on tibial defect in female Sprague Dawley (SD) rats was preliminarily verified.

Methods: This study assessed the structural and functional similarities of Salmon bone DBM (S-DBM). The biocompatibility assessment was conducted using both in vivo and in vitro experiments, establishing an animal model featuring tibial defects in rats and on the L929 cell line, respectively. The control group, bovine DBM (bDBM), was compared to the S-DBM-treated tibial defect rats. Imaging and histology were used to study implant material changes, defect healing, osteoinductive repair, and degradation.

Results: The findings of our study indicate that S-DBM exhibits favorable repairing effects on bone defects, along with desirable physicochemical characteristics, safety, and osteogenic activity.

Conclusions: The S-DBM holds significant potential as a medical biomaterial for treating bone defects, effectively fulfilling the clinical demands for materials used in bone tissue repair engineering.

Background: We investigated whether the condition of the inner surface of hollow fibers affects the blood compatibility of hemodialyzers.

Methods: We used scanning probe microscope/atomic force microscopy (SPM/AFM) to investigate the height of the swelling and flexible layers (thickness and softness) on the inner surfaces of the hollow fibers. Next, we tested the blood compatibility between dialyzers comprising a hollow fiber membrane, in which the other dialyzers, except for PVP, were additionally coated using PS membranes coated with other materials. After blood was injected into the dialyzer and plugged, dynamic stimulation was performed by slightly rotating the dialyzer for 4 h, although there was no blood circulation.

Results: The vitamin E-coated polysulfone (PS) membrane showed a higher thickness and softness of the flexible layer than the asymmetric cellulose triacetate membrane without polyvinylpyrrolidone (PVP) and the PS membranes with PVP. We found that the dialyzer with vitamin E coating significantly suppressed the decrease in platelets, increase in β-TG, and increase in PF4 compared to those coated with NV polymer. Additionally, as the adsorbed protein on the inner surface, the total protein, fibronectin, and vWF levels were significantly lower in the vitamin E-coated dialyzer.

Conclusion: The thickness and softness of the flexible layer of the inner surface of the hollow fiber membrane in vitro affect differences in blood coagulation performance in clinical research. Future clinical trials are required to confirm our results.