Exercise training as an intervention for frailty in cirrhotic patients on the liver transplant waiting list: A systematic review.

BACKGROUND: The existing literature suggests that exercise for cirrhotic patients is safe and favours significant improvement to their physical capacity. However, exercise training for this population and how to deliver activities, especially in severe stages of the disease and while waiting for a liver transplant (LT), remain undefined. AIM: To review the existing exercise prescriptions for cirrhotic patients on the waiting list for LT, their results for frailty evolution and their effect on clinical outcomes. METHODS: A systematic review was performed following the Preferred Reporting Review and Meta-Analysis guidelines and searching the PubMed, MEDLINE, and Scopus databases. The keyword "liver transplant" was used in combination with the free terms "frailty" and "exercise" for the literature review. Clinical studies that evaluated the effect of a regular training program, independent of supervision or the duration or intensity of physical exercise, in cirrhotic patients on the waiting list for LT were reviewed. The data on safe physical activity prescriptions following Frequency, Intensity, Time, and Type recommendations were extracted and summarised. RESULTS: Nine articles met the inclusion criteria for this review. Various instruments for frailty assessment were used, frequently in combination. Five studies prescribed physical activity for patients, one in-person and four to be performed remotely and unsupervised. The remaining four studies only used a self-report instrument to assess the level of physical activity. None reported adverse events related to exercise training. The exercise frequency mainly varied from daily to a minimum of twice per week. The intensity depended on frailty and included increasing levels of activity. The type of exercise was predominantly a combination of aerobic and resistance training. The duration of exercise varied from 4 to 12 wk. Three articles evaluated the effect of the exercise program on clinical outcomes, reporting a reduction in 90-d readmission rates post-transplant and improved frailty scores, as well as improved survival of cirrhotic patients waiting for LT. CONCLUSION: Routine frailty assessment is essential for this population. Although more robust evidence is required, the prescription of exercise is safe and can improve patients' functional capacity, improving pre- and post-LT outcomes.

Machine perfusion organ preservation: Highlights from the American Transplant Congress 2022.

The American Transplant Congress 2022, which took place between June 4th and June 8th of 2022, was a hybrid meeting with in-person attendance in Boston-MA and a real-time virtual experience via an online platform. First, we identified abstracts discussing machine perfusion preservation for all organs, a hot topic and approach that may develop into the new gold standard of organ preservation in the near future. A total of 39 abstracts on organ machine preservation were presented at the meeting. Next, we selected abstracts which focus on advances including new approaches to organ preservation, promising biomarkers, ex-situ treatment including cellular therapies, and novel research areas. Here, we summarized the latest developments on machine perfusion preservation in both experimental and clinical studies.

The economic impact of machine perfusion technology in liver transplantation.

INTRODUCTION: Several clinical studies have demonstrated the safety, feasibility, and efficacy of machine perfusion in liver transplantation, although its economic outcomes are still underexplored. This review aimed to examine the costs related to machine perfusion and its associated outcomes. METHODS: Expert opinion of several groups representing different machine perfusion modalities. Critical analysis of the published literature reporting the economic outcomes of the most used techniques of machine perfusion in liver transplantation (normothermic and hypothermic ex situ machine perfusion and in situ normothermic regional perfusion). RESULTS: Machine perfusion costs include disposable components of the perfusion device, perfusate components, personnel and facility fees, and depreciation of the perfusion device or device lease fee. The limited current literature suggests that although this upfront cost varies between perfusion modalities, its use is highly likely to be cost-effective. Optimization of the donor liver utilization rate, local conditions of transplant programs (long waiting list times and higher MELD scores), a decreased rate of complications, changes in logistics, and length of hospital stay are potential cost savings points that must highlight the expected benefits of this intervention. An additional unaccounted factor is that machine perfusion optimizing donor organ utilization allows patients to be transplanted earlier, avoiding clinical deterioration while on the waiting list and the costs associated with hospital admissions and other required procedures. CONCLUSION: So far, the clinical benefits have guided machine perfusion implementation in liver transplantation. Albeit there is data suggesting the economic benefit of the technique, further investigation of its costs to healthcare systems and society and associated outcomes is needed.

Machine perfusion of the liver: Putting the puzzle pieces together.

The realm of extended criteria liver transplantation created the 'adjacent possible' for dynamic organ preservation. Machine perfusion of the liver greatly expanded donor organ preservation possibilities, reaching before unattainable goals, including the mitigation of ischemia-reperfusion injury, viability assessment, and organ reconditioning prior to transplantation. However, current scientific evidence lacks uniformity between studies, perfusion protocols, and acceptance criteria. Construction of collaborative research networks for sharing knowledge should, therefore, enable the development of high-level evidence and guidelines for machine perfusion utilization, including donor acceptance criteria. Finally, this approach shall guarantee conditions for further progress to occur.

Technique of kidney transplantation in mice with anti-reflux urinary reconstruction

Experimental models of organ transplantation play a crucial role in establishing the principles of transplantation immunobiology. Murine transplant models of vascularized organs are particularly useful for immunobiological studies because there are more immunological tools available. However, the technique of kidney transplant in mice is very challenging. A difficult aspect of this model is urinary reconstruction, which is frequently associated to complications. In this article, the technique of mouse kidney transplantation using an anti-reflux system (modified extravesical ureteroneocystostomy) is described and illustrated for the first time. Although technically demanding, this procedure is feasible and may reduce the incidence of urine leakage and reflux.

Technique of kidney transplantation in mice with anti-reflux urinary reconstruction.

Experimental models of organ transplantation play a crucial role in establishing the principles of transplantation immunobiology. Murine transplant models of vascularized organs are particularly useful for immunobiological studies because there are more immunological tools available. However, the technique of kidney transplant in mice is very challenging. A difficult aspect of this model is urinary reconstruction, which is frequently associated to complications. In this article, the technique of mouse kidney transplantation using an anti-reflux system (modified extravesical ureteroneocystostomy) is described and illustrated for the first time. Although technically demanding, this procedure is feasible and may reduce the incidence of urine leakage and reflux.