Artificial organs最新文献

Introduction: Dialysis adequacy is traditionally calculated from pre- and post-hemodialysis session serum urea concentrations and expressed as the urea reduction ratio, or Kt/Vurea. However, with increasing hemodiafiltration usage, we wished to determine whether there were any differences between standard Kt/Vurea equations and directly measured spent dialysate urea clearance.

Methods: Urea clearance was measured from collected effluent dialysate and compared with various other methods of Kt/Vurea calculation, including change in total body urea from measuring pre- and post-total body water with bioimpedance and the Watson equation, by standard Kt/V equations, and online clearance measurements using effective ionic dialysance (OLC).

Results: We compared urea clearance in 41 patients, 56.1% male, mean age 69.3 ± 12.6 years with 87.8% treated by hemodiafiltration. Reduction in total body urea was greater when estimating changes in total body urea, compared to measured dialysate losses of 58.4% (48.5-67.6) vs 71.6% (62.1-78), p < 0.01. Sessional urea clearance (Kt/Vurea) was greater using the online Solute-Solver program compared to OLC, median 1.45(1.13-1.75) vs 1.2 (0.93-1.4), and 2nd generation Kt/V equations 1.3 (1.02-1.66), p < 0.01, but not different from estimated total body urea clearance 1.36 (1.15-1.73) and dialysate clearance 1.36 (1.07-1.76). The mean bias compared to the Solute-Solver program was greatest with OLC (-0.25), compared to second-generation equations (-0.02), estimated total body clearance (-0.02) and measured dialysate clearance (-0.01).

Conclusion: This study demonstrated that the result from equations estimating urea clearance indirectly from pre- and postblood samples from hemo- and hemodiafiltration treatments was highly correlated with direct measurements of dialysate urea clearance.

Background: Cardiac arrest is associated with high mortality rates and severe neurological impairments. One of the underlying mechanisms is global ischemia-reperfusion injury of the body, particularly the brain. Strategies to mitigate this may thus improve favorable neurological outcomes. The use of extracorporeal cardiopulmonary membrane oxygenation (ECMO) during CA has been shown to improve survival, but available systems are vastly unable to deliver goal-oriented resuscitation to control patient's individual physical and chemical needs during reperfusion. Recently, controlled automated reperfusion of the whoLe body (CARL), a pulsatile ECMO with arterial blood-gas analysis, has been introduced to deliver goal-directed reperfusion therapy during the post-arrest phase.

Methods: This review focuses on the device profile and use of CARL. Specifically, we reviewed the published literature to summarize data regarding its technical features and potential benefits in ECPR.

Results: Peri-arrest, mitigating severe IRI with ECMO, might be the next step toward augmenting survival rates and neurological recovery. To this end, CARL is a promising extracorporeal oxygenation device that improves the early reperfusion phase after resuscitation.

Background: The purpose of this study was to identify the association of increasing ischemic times in recipients who receive lungs evaluated by ex vivo lung perfusion (EVLP) and their association with outcomes following lung transplantation.

Methods: Lung transplant recipients who received an allograft evaluated by EVLP were identified from the United Network for Organ Sharing (UNOS) Database from 2016-2023. Recipients were stratified into three groups based on total ischemic time (TOT): short TOT (STOT, 0 to <7 h), medium TOT (MTOT, 7> to <14 h), and long TOT (LTOT, +14 h). The groups were assessed with comparative statistics and Kaplan-Meier methods. A Cox regression was created to determine the association of ischemic time in EVLP donors and long-term mortality.

Results: Recipients in the LTOT group had significantly longer length of stay and post-operative extracorporeal membrane use at 72 h (p < 0.05 for both). Additionally, they had nonsignificant increases in rate of stroke (4.7%, p = 0.05) and primary graft dysfunction grade 3 (PGD3, 27.5%, p = 0.082). However, there was no significant difference in hospital mortality or mid-term survival (p > 0.05 for both). On multivariable analysis, ischemic time was not associated with increased mortality whereas increasing recipient age, preoperative ECMO use and donation after circulatory death donors were (p < 0.05 for all).

Conclusions: If EVLP technology is available, under certain circumstances, surgeons should not be dissuaded from using an allograft with extended ischemic time.

Background: Ex vivo machine perfusion (EVMP) has been established to extend viability of donor organs. However, EVMP protocols are inconsistent. We hypothesize that there is a significant relationship between specific parameters during EVMP and perfusion outcomes.

Methods: A meta-analysis of literature was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) Statement. The search encompassed articles published before July 25, 2023. PubMed, Embase, and CENTRAL databases were screened using search terms "ex-vivo," "ex-situ," "machine," and "perfusion." Weight gain, an indicator of organ viability, was chosen to compare outcomes. Extracted variables included perfused organ, warm and cold ischemia time before perfusion, perfusion duration, perfusate flow, pressure, temperature, perfusate composition (presence of cellular or acellular oxygen carrier, colloids, and other supplements) and percent weight change. Data were analyzed using SPSS statistical software.

Results: Overall, 44 articles were included. Red blood cell-based perfusates resulted in significantly lower weight gain compared to acellular perfusates without oxygen carriers (11.3% vs. 27.0%, p < 0.001). Hemoglobin-based oxygen carriers resulted in significantly lower weight gain compared to acellular perfusates (16.5% vs. 27%, p = 0.006). Normothermic perfusion led to the least weight gain (14.6%), significantly different from hypothermic (24.3%) and subnormothermic (25.0%) conditions (p < 0.001), with no significant difference between hypothermic and subnormothermic groups (24.3% vs. 25.0%, p = 0.952). There was a positive correlation between flow rate and weight gain (ß = 13.1, R = 0.390, p < 0.001).

Conclusions: Oxygen carriers, low flow rates, and normothermic perfusate temperature appear to improve outcomes in EVMP. These findings offer opportunities for improving organ transplantation outcomes.

Background: The increasing complexity of congenital cardiac surgery has led to greater utilization of extracorporeal membrane oxygenation (ECMO) support for children post-surgery. This study aims to identify risk factors for mortality and brain injury in pediatric patients requiring post-cardiotomy ECMO and to evaluate their neurological outcomes.

Methods: This retrospective study includes pediatric patients with congenital heart diseases who required ECMO after surgery. Risk factors for in-hospital mortality and brain injury were assessed. Neurodevelopmental status was determined using the Pediatric Cerebral Performance Category (PCPC) Scale at discharge and during follow-up.

Results: Between October 2014 and May 2021, 2651 pediatric patients underwent cardiac surgery, with 90 (3.4%) requiring ECMO. The mean age was 0.6 years, ranging from 1 day to 13 years and 7 months. ECMO was implemented for 45 patients due to CPB weaning failure (NW-CPB), 24 due to postoperative low-cardiac output syndrome (LCOS), and 21 for extracorporeal cardiopulmonary resuscitation (E-CPR). ECMO weaning was achieved in 73 patients (81%), with an overall mortality rate of 36%. Pre-implant lactate levels (OR: 1.13, 95% CI: 1.03-1.25; p = 0.009) and peak bilirubin levels (OR: 1.04, 95% CI: 0.87-1.24; p = 0.69) were risk factors for in-hospital mortality. Survival rates were 79% for LCOS, 60% for NW-CPB, and 48% for E-CPR. Brain injury incidence was 33%, with E-CPR being a significant risk factor (p = 0.006) and NW-CPB being protective (p = 0.001). Follow-up in November 2023 showed significant improvement in neurodevelopmental status (p < 0.001).

Conclusion: Elevated pre-implant lactate and elevated bilirubin levels during ECMO are major risk factors for mortality. E-CPR is the primary risk factor for brain injury. Follow-up revealed significant improvements in neurodevelopmental outcomes.

Background: Ex vivo lung perfusion (EVLP) conducted outside of the transplant center has increased in recent years to mitigate its limitation by resources and expertise. We sought to evaluate EVLP performed at transplant centers and externally.

Methods: Lung transplant recipients were identified from the United Network for Organ Sharing Database. Recipients were then stratified into two groups based where they were perfused: Transplant Program (TP) or External Perfusion Centers (EPC). The groups were assessed with comparative statistics and long-term survival was assessed by Kaplan-Meier method. The groups were then 1:1 propensity and this process was repeated.

Results: EPC use was generally restricted to the Southern United States. Following matching, there were no significant differences in post-operative outcomes to include post-operative stroke, dialysis, airway dehiscence, ECMO use, ventilator use or incidence of primary graft dysfunction Grade 3. Adjusted 3-year survival was 68.9% (95% Confidence Interval [CI]: 60.9%-77.9%) for the TP group and 67.6% (95% CI: 61.0%-74.9%) for the EPC group (p = 0.69). In allografts with extended ischemia (14+ h), those in the TP group had significantly longer length of stay, prolonged ventilation and treated rejection in the 1st year, though no significant difference in mid-term survival (p = 0.66).

Conclusion: EVLP performed at an EPC can be carried out with results and survival similar to allografts undergoing EVLP at a TP. EPCs will extend the valuable resource of EVLP to lung transplant programs without the resources to perform EVLP.

Background: Patients requiring biventricular support (BIVAD) face higher morbidity than those undergoing durable left ventricular assist device (LVAD) implantation alone. The goal of the current study was to evaluate quality of life (QOL) of patients with LVAD therapy in the modern era, stratified by use of biventricular support.

Methods: All patients undergoing LVAD at our center were reviewed between October 2017 and September 2021. Patients were stratified by perioperative use of BIVAD. Patients were administered a telephone survey consisting of the Kansas City Cardiomyopathy Questionnaire (KCCQ-12) as well as free-responses regarding satisfaction surrounding their operation. Outcomes included survival, KCCQ-12 metrics, and thematic analysis of free response questions.

Results: 92 patients were identified, of whom 26 (28%) received BIVAD support. BIVAD patients had more preoperative ECMO use (54% vs. 12%, p < 0.001) and lower INTERMACS scores (Category 1: 46% vs. 14%, p = 0.001). Three-year survival was 73.8% among LVAD-alone patients and 50.1% among BIVAD patients (log-rank p = 0.022). Median composite KCCQ-12 score was 78 (57-88). No differences in composite or any component scores were noted between groups. 76% of patients report they would be moderately or extremely like to go through surgery again if given repeat choice. The most common themes expressed were overall gratitude (24%) and disappointment with device-related restrictions (20%).

Conclusions: Patients requiring BIVAD therapy have more advanced shock, longer associated hospital courses, and lower long-term survival. However, those that survive enjoy similar overall quality of life, and many endorse positive outlooks on their surgical course. Continued assessments of quality of life are important in providing patient-centered LVAD care.