The role of prehabilitation on short-term outcomes after liver transplantation: A review of the literature and expert panel recommendations

Prediction and management of small-for-size syndrome in living donor liver transplantation

Small-for-size syndrome (SFSS) remains a critical challenge in living donor liver transplantation (LDLT), characterized by graft insufficiency due to inadequate liver volume, leading to significant postoperative morbidity and mortality. As the global adoption of LDLT increases, the ability to predict and manage SFSS has become paramount in optimizing recipient outcomes. This review provides a comprehensive examination of the pathophysiology, risk factors, and strategies for managing SFSS across the pre-, intra-, and postoperative phases. The pathophysiology of SFSS has evolved from being solely volume-based to incorporating portal hemodynamics, now recognized as small-for-flow syndrome. Key risk factors include donor-related parameters like age and graft volume, recipient-related factors such as MELD score and portal hypertension, and intraoperative factors related to venous outflow and portal inflow modulation. Current strategies to mitigate SFSS include careful graft selection based on graft-to-recipient weight ratio and liver volumetry, surgical techniques to optimize portal hemodynamics, and novel interventions such as splenic artery ligation and hemiportocaval shunts. Pharmacological agents like somatostatin and terlipressin have also shown promise in modulating portal pressure. Advances in 3D imaging and artificial intelligence-based volumetry further aid in preoperative planning. This review emphasizes the importance of a multifaceted approach to prevent and manage SFSS, advocating for standardized definitions and grading systems. Through an integrated approach to surgical techniques, hemodynamic monitoring, and perioperative management, significant strides can be made in improving the outcomes of LDLT recipients. Further research is necessary to refine these strategies and expand the application of LDLT, especially in challenging cases involving small-for-size grafts.

Cardiorespiratory Fitness From Cardiopulmonary Exercise Testing Is a Comprehensive Risk-stratifying Tool in Liver Transplant Candidates

Background

Cardiovascular disease and physical decline are prevalent and associated with morbidity/mortality in liver transplant (LT) patients. Cardiopulmonary exercise testing (CPX) provides comprehensive cardiopulmonary and exercise response assessments. We investigated cardiorespiratory fitness (CRF) and cardiac stress generated during CPX in LT candidates.

Methods

LT candidates at 2 centers underwent CPX. Standard-of-care cardiac stress testing (dobutamine stress echocardiography, DSE) results were recorded. Physical function was assessed with liver frailty index and 6-min walk test. CPX/DSE double products were calculated to quantify cardiac stress. To better study the association of CPX-derived metrics with physical function, the cohort was divided into 2 groups based on 6-min walk test median (372 m).

Results

Fifty-four participants (62 ± 8 y; 65% men, Model for End-Stage Liver Disease-Na 14 [10-18]) underwent CPX. Peak oxygen consumption was 14.1 mL/kg/min for an anerobic threshold of 10.2 mL/kg/min, with further CRF decline in the lower 6MWT cohort despite lack of liver frailty index-frailty in 90%. DSE was nondiagnostic in 18% versus 4% of CPX (P = 0.058). All CPX were negative for ischemia. A double product of ≥25 000 was observed in 32% of CPX and 11% of DSE (P = 0.020). Respiratory function testing was normal. No patient presented major cardiovascular events at 30 d post-LT.

Conclusions

CPX provided efficient and effective combined cardiopulmonary risk and frailty assessments of LT candidates in a 1-stop test. The CRF was found to be very low despite preserved physical function or lack of frailty.

Frailty in liver transplantation: Exploring prescribing exercise as medicine to improve patient outcomes

Liver transplantation (LT) represents a curative avenue for individuals with advanced chronic liver disease. Given the inherent illness severity of LT candidates, identifying patients at greater risk for adverse outcomes before and after transplantation is paramount. Approximately 50% of cirrhotic patients are frail and have considerable functional impairment. Various measures have been used to assess frailty, including performance-based tests and functional status evaluations. Frailty carries significant prognostic implications and predicts both mortality and pre- and post-LT complications. Contributing factors to frailty in this population include sarcopenia, malnutrition, inflammation, and psychosocial factors. Recognizing the prevalence of frailty among LT candidates, exercise interventions have been developed to improve physical frailty and offer potential to improve patient outcomes. While many interventions have demonstrated efficacy without notable adverse events, the absence of a universally accepted standard for exercise prescription underscores the variability in intervention elements and patient adherence. Given the safety profile of exercise interventions, there remains a critical need for standardized protocols and guidelines to optimize exercise regimens for LT candidates. This review delves into the landscape of frailty among LT candidates, elucidating its etiological underpinnings, impact on outcomes, utilization of exercise interventions, and the efficacy of exercise programs in reducing the burden frailty in those awaiting LT.

Prehabilitation in patients awaiting liver transplantation

BACKGROUND

Frailty, malnutrition and sarcopenia lead to a significant increase in morbidity and mortality before and after liver transplantation (LT). Prehabilitation attempts to optimize physical fitness of individuals before major surgeries. To date, little is known about its impact on patients awaiting LT.

AIMS

The aim of our scoping review was to describe whether prehabilitation in patients awaiting LT is feasible and safe, and whether it leads to a change in clinical parameters before or after transplantation.

METHODS

We performed a systematic review of the literature from 1946 to November 2023 to identify prospective studies and randomized controlled trials of adult LT candidates who participated in an exercise training program.

RESULTS

Out of 3262 citations initially identified, six studies were included. Studies were heterogeneous in design, patient selection, intervention, duration, and outcomes assessed. All studies were self-described as pilot or feasibility studies and had a sample size ranging from 13 to 33. Two studies were randomized controlled trials. Two study restricted to patients with cirrhosis who were eligible for liver transplantation or on the transplant list. Exercise programs lasted between 6 and 12 weeks. In terms of feasibility, proportion of eligible patients that were recruited was between 54 and 100%. Program completion ranged between 38 and 90%. Interventions appeared safe with 9 (9.2%) adverse events noted. In the intervention group, improvements were generally noted in peak oxygen consumption and workload, 6-min walking distance, and muscle strength. One study suggested a decrease in post-transplant hospital length of stay.

CONCLUSIONS

Overall, it appears that prehabilitation with exercise training is feasible, and safe in patients awaiting LT. Higher quality and larger studies are needed to confirm its impact on pre- and post-transplantation-related outcomes.

Nutritional aspects of prehabilitation in adults with cirrhosis awaiting liver transplant

Malnutrition, sarcopenia (low muscle mass), and physical frailty have gained increasing recognition in candidates for liver transplant (LT) as these conditions can impact postoperative functional capacity. Multidimensional prehabilitation programs have been proposed as a safe intervention in adults awaiting LT but the nutritional pillar of prehabilitation has been understudied. This review summarizes the nutritional recommendations for prehabilitation for individuals with cirrhosis awaiting LT. Three major aspects of nutritional prehabilitation are discussed: (1) Assess: Evaluate nutritional status and assess for malnutrition, sarcopenia, and frailty to guide the nutritional prehabilitation intervention intensity, increasing across universal, targeted, and specialist levels; (2) Intervene: Prescribe a nutritional prehabilitation intervention to meet established nutrition guidelines in cirrhosis with a targeted focus on improving nutritional status and muscle health; (3) Reassess: Follow-up based on the required intensity of nutritional care with as needed intervention adjustment. Topics covered in the review include nutritional care levels for prehabilitation, energy prescriptions across body mass index strata, detailed considerations around protein intake (amount, distribution, and quality), carbohydrate and fat intake, other nutritional considerations, and the potential role of dietary supplements and nutraceuticals. Future research is warranted to more accurately evaluate energy needs, evaluate emerging dietary supplementation strategies, and establish the role of nutraceuticals alongside food-based interventions. While the general principles of nutritional prehabilitation are ready for immediate application, future large-scale randomized controlled trials in this space will help to quantify the benefit that can be gained by transitioning the LT approach from passive "transplant waitlist time" to active "transplant preparation time."

Consensus document from the Spanish Society for Liver Transplantation: Enhanced recovery after liver transplantation

The goal of the Spanish Society for Liver Transplantation (Sociedad Española de Trasplante Hepático) is to promote and create consensus documents about current topics in liver transplantation with a multidisciplinary approach. To this end, in November 2022, the 10th Consensus Document Meeting was held, with the participation of experts from the 26 authorized Spanish liver transplantation programs. This edition discusses enhanced recovery after liver transplantation, dividing needed actions into 3periods: preoperative, intraoperative and postoperative. The evaluated evidence and the consensus conclusions for each of these topics are described.

Consensus document from the Spanish Society for Liver Transplantation: enhanced recovery after liver transplantation

The goal of the Spanish Society for Liver Transplantation (La Sociedad Española de Trasplante Hepático) is to promote and create consensus documents about current topics in liver transplantation with a multidisciplinary approach. To this end, in November 2022, the 10th Consensus Document Meeting was held, with the participation of experts from the 26 authorized Spanish liver transplantation programs. This edition discusses Enhanced Recovery After Liver Transplantation, dividing needed actions into three periods: preoperative, intraoperative and postoperative. The evaluated evidence and the consensus conclusions for each of these topics are described.

Enhanced recovery after surgery for liver transplantation: a review of recent literature

PURPOSE OF REVIEW

This review was created to highlight important articles from the past year related to the evolving field of enhanced recovery after surgery (ERAS) in liver transplantation that are relevant to the transplant anesthesiologist.

RECENT FINDINGS

The International Liver Transplantation Society (ILTS) recently completed a landmark project, the ERAS4OLT.org project, which culminated in 80 recommendations for ERAS in liver transplantation. These recommendations encompass management for deceased donor recipients, living donor recipients and living donors. This review highlights selected articles relevant to the perioperative management of deceased donor liver transplant recipients.

SUMMARY

Though, there are now published internationally agreed upon recommendations for ERAS topics specific to liver transplantation, there is an obvious need for further investigation into this area to provide high quality evidence to support these recommendations. It is reasonable to utilize these recommendations in ERAS protocols for individual institutions; however, more evidence is needed in several areas to confirm the effects of these protocols on short-term outcomes.

The influence of prehabilitation in patients with liver cirrhosis before liver transplantation: a randomized clinical trial

BACKGROUND

The high prevalence of liver cirrhosis in Slovakia leads to a great need for transplant treatment. The outcome of liver transplantation is influenced by several factors.

AIM

The main objective of this study is to test the effectiveness of prehabilitation compared to standard of care.

DESIGN

Prospective, double-arm, randomized, open-registry study.

SETTING

Patient in F. D. Roosevelt Teaching Hospital, Slovakia, Banská Bystrica.

POPULATION

The participants consisted of patients with liver cirrhosis (55 men, 25 women).

METHODS

The patients were randomized to the active prehabilitation group (N.=39) or the standard of care group (SOC) (N.=41). SOC represents the standard of care for patients prior to liver transplantation, consisting of a formal oral interview lasting 30 minutes. In addition to SOC, each patient with decompensated liver cirrhosis also underwent a prehabilitation intervention that included rehabilitation and nutrition support. Patients completed the exercises under the supervision of a physician during hospitalisation.

RESULTS

After one month, the liver frailty index improved in the prehabilitation group (P=0.05). No improvement in MELD (Model of End Stage Liver Disease) was found in the group that underwent the prehabilitation program (P=0.28), and no improvement was found in the Child-Pugh score after one month (P=0.13). In the prehabilitation groups compared with the SOC group, differences were not found in the MELD score (P=0.11). Better clinical outcomes according to the Child-Pugh score was found for the prehabilitation group compared with the SOC group (P=0.02). According to LFI, there was no difference between the groups (P=0.26). Very low adherence was found after three months. Only three patients in the SOC group and six patients in the prehabilitation group came to the check-up. Due to low adherence after 3 months in patients with liver cirrhosis, it is not possible to make an adequate comparison between groups after three months.

CONCLUSIONS

Despite the great effort to maintain adherence, it was not possible to draw a conclusion about the effectiveness of prehabilitation in patients before liver transplantation compared to standard of care because the main problem in Slovak patients with liver cirrhosis is low adherence. More studies are needed to identify the barriers that lead to low adherence in patients with liver cirrhosis.

CLINICAL REHABILITATION IMPACT

A promising result was found due to improvement of the Liver Frailty Index and the Child-Pugh Score after one month in the prehabilitation group.

Getting your transplant center ready for prime time: Health care system obstacles to prehabilitation

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Assessing the risk of surgery in patients with cirrhosis

Patients with cirrhosis have an increased perioperative risk relative to patients without cirrhosis. This is related to numerous cirrhosis-specific factors, including severity of liver disease, impaired synthetic function, sarcopenia and malnutrition, and portal hypertension, among others. Nonhepatic comorbidities and surgery-related factors further modify the surgical risk, adding to the complexity of the preoperative assessment. In this review, we discuss the pathophysiological contributors to surgical risk in cirrhosis, key elements of the preoperative risk assessment, and application of risk prediction tools including the Child-Turcotte-Pugh score, Model for End-Stage Liver Disease-Sodium, Mayo Risk Score, and the VOCAL-Penn Score. We also detail the limitations of current approaches to risk assessment and highlight areas for future research.

Enhanced recovery for liver transplantation: recommendations from the 2022 International Liver Transplantation Society consensus conference

There is much controversy regarding enhanced recovery for recipients of liver transplants from deceased and living donors. The objectives of this Review were to summarise current knowledge on individual enhanced recovery elements on short-term outcomes, identify key components for comprehensive pathways, and create internationally accepted guidelines on enhanced recovery for liver-transplant recipients. The ERAS4OLT.org collaborative partnered by the International Liver Transplantation Society performed systematic literature reviews on the effect of 32 relevant enhanced perioperative recovery elements on short-term outcomes, and global specialists prepared expert statements on deceased and living donor liver transplantation. The Grading Recommendations, Assessment, Development and Evaluations approach was used for rating of quality of evidence and grading of recommendations. A virtual international consensus conference was held in January, 2022, in which results were presented, voted on by the audience, and discussed by an independent international jury of eight members, applying the Danish model of consensus. 273 liver transplantation specialists from 30 countries prepared expert statements on elements of enhanced recovery for liver transplantation based on the systematic literature reviews. The consensus conference yielded 80 final recommendations, covering aspects of enhanced recovery for preoperative assessment and optimisation, intraoperative surgical and anaesthetic conduct, and postoperative management for the recipients of liver transplants from both deceased and living donors, and for the living donor. The recommendations represent a comprehensive overview of the relevant elements and areas of enhanced recovery for liver transplantation. These internationally established guidelines could direct the development of enhanced recovery programmes worldwide, allowing adjustments according to local resources and practices.