Artificial organs最新文献

Background: Normothermic machine perfusion has emerged as a valuable technique for organ preservation, enabling liver viability assessment and reducing the discard rates of marginal grafts. However, the standard protocol involves two cooling/rewarming phases, which can result in a double ischemia/reperfusion injury that increases the risk of graft dysfunction.

Methods: We describe a novel surgical technique, named quasi ischemia-free liver procurement, which circumvents cold ischemia during liver procurement, thereby minimizing ischemia-reperfusion injury.

Results: In this study, we applied quasi-ischemia-free liver procurement to an orphan liver graft from a 43-year-old deceased brain donor. The liver was subsequently transplanted into a 66-year-old male recipient with alcoholic liver cirrhosis and hepatocellular carcinoma. The technique was successful, with ex-situ normothermic perfusion beginning within 3 min of graft disconnection without graft cooling and lasting for nearly 4 h. The graft exhibited excellent viability, evidenced by immediate lactate clearance, stable transaminase levels, and good bile production during machine perfusion. The recipient experienced an uneventful postoperative course with immediate graft function and was discharged on postoperative day 8.

Conclusions: Quasi ischemia-free liver procurement represents a simpler alternative to ischemia-free liver transplantation, potentially simplifying the implantation phase. This technique holds promise for improving outcomes in liver transplantation, particularly in cases involving marginal grafts.

Machine perfusion has revolutionized organ preservation by enabling enhanced graft viability, real-time functional assessment, and targeted therapeutic interventions. However, isolated organ perfusion models may fail to replicate the physiological interplay between abdominal organs. Ex situ multivisceral perfusion offers a promising alternative by maintaining critical inter-organ relationships, potentially improving the viability of low-flow organs, better mimicking in situ physiology, and extending preservation times. This approach may be especially beneficial for multivisceral transplant recipients, who often present with complex clinical needs and limited options. A central challenge in developing multivisceral perfusion strategies is defining and measuring perfusion success. Key indicators include macroscopic graft appearance, hemodynamic and biochemical parameters during perfusion, and post-perfusion histological evaluation. Over the course of perfusion, characteristic changes such as bowel distension and loss of peristalsis may occur, especially during prolonged cases. Successful perfusion is marked by homogeneous graft perfusion, stable arterial flows at physiological pressures, minimal edema, effective lactate clearance, preserved perfusate pH, and sustained bile and urine production without excessive fluid losses. Here, we present a comprehensive, stepwise protocol for normothermic machine perfusion of porcine abdominal multivisceral grafts, designed to support preclinical development and translational efforts aimed at improving organ preservation and expanding the potential of multivisceral transplantation.

Background: Weaning from extracorporeal life support (ECLS) in patients with refractory shock still remains a complex decision. Despite considerable advances in ECLS management, reliable biomarkers to predict weaning success are still not available. Inflammatory cytokines including interleukin-6 (IL6), interleukin-8 (IL8), and tumor necrosis factor-alpha (TNF-α) may reflect systemic immune response and have been proposed as potential predictors of deterioration or recovery.

Methods: A retrospective, single-center study analyzed 809 patients with ECLS between 2012 and 2024. Serum levels of IL6, IL8, and TNF-α were measured before ECLS and 24 h after initiation. Receiver operating characteristic (ROC) analysis and subgroup comparisons between clinical phenotypes were used to assess the cytokine predictive value.

Results: Weaning was achieved in 66.9% of patients. IL8 levels after 24 h demonstrated the highest predictive accuracy for weaning failure (area under the curve AUC = 0.73), outperforming IL6 and TNF-α. The decline of IL8 levels during the first 24 h was associated (p = 0.008) with successful weaning. Subgroup analysis revealed that the predictive values of IL6 and IL8 were pronounced in patients with pulmonary embolism (AUC = 0.72, IL6) and septic shock (AUC = 0.77, IL8), with significantly elevated cytokine levels. Patients with structural heart disease (AUC = 0.85, IL6) and ventricular arrhythmias (AUC = 0.82, IL6) showed cytokine levels comparable to the whole cohort and a better prediction.

Conclusion: Among the evaluated cytokines, IL8 exhibited the strongest predictive benefit for weaning failure, especially on Day 1. Due to its early clearance dynamics, it may be a useful parameter in the appropriate clinical situation to achieve a better outcome.

A novel single-incision anterolateral thoracotomy technique enables complete HeartMate 3 implantation without sternotomy, minimizing surgical trauma and accelerating recovery. This minimally invasive approach is feasible, safe, and may represent a new standard in advanced heart failure surgery.

Background: Hypothermic ex situ heart graft perfusion using acellular preservation solution is a promising technique for heart transplantation.

Methods: We investigated the cardioprotective effects of a novel preservation solution, IGL-2 (Institut Georges Lopez, France), in a porcine model of hypothermic ex situ heart perfusion over 4 h, following either beating-heart procurement or donation after circulatory death.

Results: Coronary endothelial injury (assessed by Endothelin-1) and oxidative stress markers (assessed by nitrates and hydrogen peroxide) were evaluated through repeated perfusate sampling. Cardiac power output was measured after ex situ warm reperfusion in working mode.

Conclusion: Preservation with IGL-2 was associated with reduced endothelial injury and oxidative stress, resulting in improved myocardial recovery following blood reperfusion.

Background: Neural conduits (NGCs) are widely used for peripheral nerve regeneration but have shown limited therapeutic effects. Electrical stimulation combined with NGCs is becoming a new treatment paradigm. Conventional electrical stimulation approaches for nerve regeneration are typically hindered by inconvenience, infection, and may cause secondary damage.

Methods: This study developed a non-contact electrical stimulation platform using a magnetic field-coupled polycaprolactone/conductive polymer poly(3,4-ethylenedioxythiophene)/black phosphorus nerve conduit. This composite nerve conduit exhibited excellent electrical properties and biocompatibility. When placed in an external rotating magnetic field, it was able to transmit pulsed currents into the targeted sites due to electromagnetic induction.

Results: The regeneration levels achieved with the magnetic field-driven nerve conduit were comparable to those of autologous transplantation. Immunofluorescence and histochemistry results demonstrated that this magnetic field-driven nerve conduit enhances axonal regeneration, neovascularization, and inflammation regulation.

Conclusion: This work opens a new avenue for low-invasive and high-security bioelectronic therapy for long-segment peripheral nerve defects, with potential applications in various tissue regeneration engineering.

An LVAD patient with severe aortic regurgitation (AR) developed right heart failure and multi-organ dysfunction (MOD). tRVAD support caused LV overload and pulmonary edema. Impella 5.5 implantation successfully unloaded the LV and stabilized the patient, enabling durable RVAD implantation with surgical aortic valve replacement.

Vascularized composite allotransplantation (VCA) offers unparalleled reconstructive possibilities in complex cases but remains constrained by high immunogenicity and marked susceptibility to ischemia-reperfusion injury (IRI), particularly in muscle-rich grafts. Static cold storage (SCS), the current clinical standard, preserves grafts only for short durations. In contrast, machine perfusion (MP), already transformative in solid organ transplantation, is emerging as a promising strategy for VCA. This review summarizes the main challenges of ex vivo VCA preservation and current perfusion strategies designed to overcome them. Particular attention is given to physiological and technical factors influencing graft integrity, as well as innovations in perfusate composition and protective additives that mitigate IRI and support tissue preservation. Beyond simple storage, MP platforms enable functional assessment and therapeutic interventions, including graft reconditioning and immune modulation prior to transplantation. Complementary subzero static preservation methods, such as supercooling and cryopreservation, also show promise for substantially extending preservation times. Together with advances in experimental models, these approaches are reshaping the preservation landscape. As the field evolves, MP is poised to become a cornerstone technology in VCA, improving graft quality, extending preservation duration, and enabling pre-implantation modification strategies to reduce rejection and enhance long-term outcomes.

Background: In the United States, the donor heart allocation policy change in October 2018 granted high priority to patients on temporary mechanical circulatory support (MCS), positively influencing their pre-transplant outcomes with reduced waitlist time. However, the impact of this policy change on patients requiring biventricular support remains undetermined.

Methods: We analyzed data from the United Network for Organ Sharing (UNOS) database from May 2013 to March 2024. Patients with biventricular assist devices (BiVADs), including temporary or durable devices, and total artificial hearts (TAHs) were included. The cohort was divided into two groups based on listing: before and after policy change groups. Waitlist and post-transplant survival were compared between both groups.

Results: Patients on biventricular support comprised 1.5% (611/39 829) of all waitlisted candidates, and 2.6% (732/28 643) of all isolated heart transplants. There was a significantly lower prevalence of biventricular support after the policy change in both waitlisted candidates (Pre: 2.0% versus Post: 1.2%, p < 0.001) and at the time of transplantation (Pre: 3.1% versus Post: 2.1%, p < 0.001). Following the policy change, there was a significantly lower median waitlist time (Pre: 88 [29-190] days versus Post: 22 [7-69] days, p < 0.001), and a higher proportion of transplanted patients (Pre: 65% versus Post: 85%, p < 0.001). Both waitlist survival (p < 0.001) and post-transplant survival (p = 0.05) improved after the policy change.

Conclusions: The 2018 policy revision was associated with a decline in biventricular support utilization in both waitlisted and transplanted cohorts. This shift corresponded with shorter waitlist durations, more frequent transplants, and better waitlist and post-transplant survival.