International Journal of Artificial Organs最新文献

Centrifugal blood pumps can be used for treating heart failure patients. However, pump thrombosis has remained one of the complications that trouble clinical treatment. This study analyzed the effect of impeller shroud on the thrombosis risk of the blood pump, and predicted areas prone to thrombosis. Multi-constituent transport equations were presented, considering mechanical activation and biochemical activation. It was found that activated platelets concentration can increase with shear stress and adenosine diphosphate(ADP) concentration increasing, and the highest risk of thrombosis inside the blood pump was under extracorporeal membrane oxygenation (ECMO) mode. Under the same condition, ADP concentration and thrombosis index of semi-shroud impeller can increase by 7.3% and 7.2% compared to the closed-shroud impeller. The main reason for the increase in thrombosis risk was owing to elevated scalar shear stress and more coagulation promoting factor-ADP released. The regions with higher thrombosis potential were in the center hole, top and bottom clearance. As a novelty, the findings revealed that impeller shroud can influence mechanical and biochemical activation factors. It is useful for identifying potential risk regions of thrombus formation based on relative comparisons.

With the general population aging, both life expectancy and the number of left ventricular assist device (LVAD) implantations in elderly patients are growing. Nevertheless, their perceived long-term quality of life, including psychological aspects, coupled with the respective caregiver's burden, remain under-reported. In light of the rising number of octogenarians with LVAD who necessitate broader healthcare provider involvement, we assessed the long-term quality of life, as defined by both the 36-item short-form health (SF-36) survey and the EuroQol 5 dimensions, 5-level questionnaire (EQ-5D-5L)-including the visual analog scale-in octogenarian LVAD patients who had received treatment at our institution. Additionally, we evaluated the psychological health of octogenarian LVAD patients using the psychological general well-being index (PGWBI), alongside their caregivers' well-being through the 22-item version of the Zarit Burden Interview (ZBI). Of 12 octogenarian LVAD patients, 5 were alive and willing to answer questionnaires. Mean age at implant was 74 ± 2 years. Median follow-up was 2464 (IQR = 2375-2745) days. Although variable, the degree of health and psychological well-being perceived by octogenarian patients with LVAD was "good." Interestingly, the burden of assistance reported by caregivers, though relevant, was greatly varied, suggesting the need to better define and address psychological long-term aspects related to LVAD implantation for both patients and caregivers with a broad-spectrum approach.

Background: Middle uremic toxins (MUTs) can cause anemia and erythropoietin hyporesponsiveness. Theranova dialyzers may improve anemia management by removing MUTs. Hence, the impact of Theranova dialyzers on erythropoietin responsiveness was studied.

Methods: This exploratory single-center prospective observational study, encompassing 50 patients undergoing dialysis with either the Theranova-400 or FX80 membrane for 6 months, involved monthly tracking of hemoglobin levels, weight-adjusted erythropoiesis-stimulating agent (w-ESA) dosing, and erythropoietin resistance index (ERI), with ESA treatment decisions guided by a proprietary algorithm.

Results: The groups were similar in terms of demographics and baseline laboratory test results. The median hemoglobin levels, w-ESA and ERI, were found to be similar between FX80 and Theranova-400 groups at both baseline (11.06 vs 10.57, p = 0.808; 92.3 vs 105.2, p = 0.838; 8.1 vs 10.48, p = 0.876) and the end of the study (11.43 vs 11.03, p = 0.076; 48.7 vs 71.5; 4.48 vs 6.41, p = 0.310), respectively. There was a trend toward lower w-ESA and ERI at the end of the study compared to baseline in both groups, but the difference was non-significant.

Conclusions: Based on this study of 50 patients undergoing high-flux dialysis with near-target hemoglobin levels, switching to Theranova 400 dialyzers compared to FX80 dialyzers did not show statistically significant differences in maintaining hemoglobin levels, reducing ESA dose, or lowering ERI. The non-randomized design and small sample size limit the study's power to detect true differences. Larger, randomized trials are needed to confirm findings and definitively assess Theranova 400's benefits.

Abdominal vein replacement with synthetic tissue-engineered vascular grafts constructed from silk-based scaffold material has not been reported in middle-sized mammals. Fourteen canines that underwent caudal vena cava replacement with a silk fibroin (SF) vascular graft (15 mm long and 8 mm diameter) prepared with natural silk biocompatible thread were allocated to two groups, thin and thick SF groups, based on the graft wall thickness. The short-term patency rate and histologic reactions were compared. The patency rate at 2 weeks after replacement in the thin and thick SF groups was 50% and 88%, respectively (p = 0.04). CD31-positive endothelial cells covered the luminal surface of both groups at 4 weeks. The elastic modulus of the thick SF graft was significantly better than that of the thin SF graft (0.0210 and 0.0007 N/m², p < 0.01). Roundness of thick SF groups (o = 0.8 mm) was better than thin SF (o = 2.0 mm). There was significant difference between the groups (p = 0.01). SF vascular grafts are a promising tissue-engineered scaffold material for abdominal venous system replacement in middle-sized mammals, with thick-walled grafts being superior to thin-walled grafts.

The incidence of Mycobacterium tuberculosis (Mtb) infection in patients with mechanical circulatory support devices is extremely rare. We present a case involving a 38-year-old male who experienced a delayed sternal Mtb infection following left ventricular assist device (LVAD) implantation. More than 5 months post-surgery, the patient was readmitted to the hospital presenting a subxiphoid abscess. The incision site displayed an unsatisfactory healing process after the incision and drainage of the abscess. Despite engaging in a rigorous treatment protocol, which included anti-infective therapy, vacuum-assisted closure, and surgical debridement, the patient's wound remained unhealed. Ultimately, after pus gene sequencing confirmed the diagnosis, the patient was administered a regimen combining anti-tuberculosis and anti-infective therapy, which culminated in the successful healing of the wound. This singular case study not only reveals the clinical progression of an unexpected Mtb infection post-implantation but also emphasizes the challenges encountered in diagnosis and management.

Objective: Sex-specific differences in the epidemiology of chronic kidney disease, such as higher prevalence of women on pre-dialysis and men on chronic dialysis treatment, have been reported worldwide. In this regard, data from non-high-income countries are scarce. We aimed to compare the demographic, clinical, and dialysis characteristics of incident dialysis patients, both men and women, in a large cohort of Brazilian patients over a 12-year period.

Methods: This was a multicentric retrospective cohort study coordinated by the Brazilian Society of Nephrology. The study included all adult incident dialysis patients in the Brazilian Dialysis Registry from January 2011 to December 2022. The variables studied encompassed age, skin color, education, CKD etiology, predialysis nephrologist care, dialysis characteristics, and geographic region. Additionally, the sample was analyzed for each of the three 4-year periods over the 12 years of data collection.

Results: A total of 24,632 incident dialysis patients were included. Men were 59.1% of the dialysis population, remaining stable over the three 4-year periods. Besides other differences, women started dialysis younger (58.5 ± 16.2 years vs 59.5 ± 14.4 years; p < 0.001), had a lower educational level (less than 8 years at school: 54% vs 44%; p < 0.001), received more predialysis nephrologist care (46.2% vs 44.2%; p = 0.04), and had a higher prevalence of peritoneal dialysis (4.4% vs 3.5%; p = 0.03).

Conclusion: We consistently observed a higher prevalence of men on dialysis and differences in demographic, clinical, and dialysis characteristics. The underlying reasons for these sex differences still necessitate further clarification.

Background: mRNA vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became common. We investigated the optimal timing for inoculation against SARS-COV-2 in the candidates for cardiac surgery under cardiopulmonary bypass (CPB).

Methods: In 100 patients with preoperative vaccination, who underwent CPB surgery between July 2021 and February 2022, the IgG against the receptor binding domain (RBD-IgG), with a threshold of >100 binding antibody unit (BAU)/mL for adequate immunity, was measured.

Results: The vaccines, including 87 BNT162b2 (Pfizer/BioNTech) and 13 mRNA-1273 (Moderna), were inoculated at 98.8 ± 59.4 days before surgery. The median RBD-IgG titers before surgery, 1 day after surgery, and 1 month after surgery were 166.8, 100.0, and 84.0 BAU/mL, respectively. The standby interval (SBI) from the vaccination to the surgery showed a significantly negative correlations with the RBD-IgG titer before the surgery (p < 0.001). A cut-off SBI for RBD-IgG >100 BAU/mL before surgery was <81 days with a sensitivity of 76%, specificity of 62%, and area under ROC value of 0.73 (p = 0.03). The patients with SBI <81 days (n = 48) had significantly higher RBD-IgG (>100 BAU/mL) than those with SBI ⩾81 days (n = 52) at all perioperative periods.

Conclusions: Although 40% of the RBD-IgG titers reduce 1 day after CPB surgery, the patients who received the SARS-COV-2 vaccination within an 81-day window prior to the surgery maintained a desirable RBD-IgG level, even up to 1 month after surgery. It may be important to schedule the surgery no later than 81 days after the vaccination.

Several similarities have been found between shear stress-induced erythrocyte damage and physiological aging of erythrocytes in terms of elevated mechanical fragility, increased erythrocyte aggregation, and decreased membrane surface charge. Accordingly, we hypothesized that blood pump circulation, which generates shear stress, would accelerate erythrocyte aging, manifesting as oxidation. Therefore, the purpose of this study was to investigate the effect of blood pump circulation on erythrocyte oxidation. Fresh porcine blood was acquired from a slaughterhouse and anticoagulated with sodium citrate. About 500 mL of anticoagulated whole blood was circulated for 180 min in an in vitro test circuit comprising a BP-80 blood pump with a pump speed and a pump pressure head of 100-120 mmHg. A blood sample was taken at the start of the circulation and 180 min afterward. The hemolysis level and oxidation amount of the erythrocyte membrane were analyzed and compared between samples. Hemolysis increased with the prolongation of shear exposure inside the pump circuit. After 180 min of blood pumping in circuit, the oxidation level of the erythrocyte membrane showed an increase of 0.1 nmol/mg protein. Moreover, the membrane oxidation levels of sheared erythrocytes were greater than those of control erythrocytes. These results suggest that blood pump circulation accelerates erythrocyte aging and give us a greater understanding of the effects of blood pump perfusion.

Aim: Use of microaxial mechanical circulatory support (MCS) has been reported for severe graft rejection or dysfunction after heart transplantation (HTx). We aimed to assess utilization patterns of microaxial MCS after HTx in adolescents (ages 18 and younger) and adults (ages 19 and older).

Methods: Electronic search was performed to identify all relevant studies on post-HTx use of microaxial support in adults and adolescents. A total of 18 studies were selected and patient-level data were extracted for statistical analysis.

Results: All patients (n=23), including adults (n=15) and adolescents (n=8), underwent Impella (Abiomed, Danvers, MA) microaxial MCS after HTx. Median age was 36 [IQR 18-56] years (Adults, 52 [37-59]; adolescents, 16 [15-17]). Primary right ventricular graft dysfunction was an indication exclusively seen in the adults 40% (6/15), while acute graft rejection was present in 46.7% (7/15) of adults. Median time after transplant was 9 [0-32] months (Adults, 4 [0-32]; adolescents, 11 [4.5, 45]). Duration of Impella support was comparable between adults and adolescents (5 [2.5-8] vs 6 [5-8] days, p = 0.38). Overall improvement was observed both in median LV ejection fraction (23.5% [11.3-28] to 42% [37.8-47.3], p < 0.01) and cardiac index (1.8 [1.2-2.6] to 3 [2.5-3.1], p < 0.01). Retransplantation was required in four adolescents (50%, 4/8). Survival to discharge was achieved by 60.0% (9/15) of adults and 87.5% (7/8) of adolescents respectively (p = 0.37).

Conclusion: Indications for microaxial MCS appear to vary between adult and adolescent patients. Overall improvement in LVEF and cardiac index was observed, however, with suboptimal survival to discharge.

With rates of ECMO utilization on the rise, prevention of nosocomial infections is of paramount importance. Candida auris, an emerging highly pathogenic multidrug resistant fungus, is of particular concern as it is associated with persistent colonization of environmental surfaces, inability to be recognized by many diagnostic platforms, inconsistent laboratory susceptibility results, and high mortality rates. We describe a case of C. auris in a VV-ECMO patient successfully managed with a combination of anidulafungin, amphotericin B, and flucytosine.