Update on combined heart and liver transplantation: evolving patient selection, improving outcomes, and outstanding questions

Liberal use of veno-arterial extracorporeal membrane oxygenation in combined sequential heart-liver transplantation

Combined heart-liver transplantation (CHLT) is a rarely though increasingly performed procedure with evolving indications. Despite CHLT being performed at only a handful of centers, the use of intraoperative mechanical circulatory support to optimize hemodynamics and facilitate dual-organ transplantation varies widely. At our center, we liberally utilize veno-arterial extracorporeal membrane oxygenation (V-A ECMO) when a veno-venous shunt is anticipated to be insufficient in mitigating the hemodynamic perturbations associated with liver reperfusion. In this series, we describe our experience with V-A ECMO in sequential (heart-first) CHLT and demonstrate highly favorable outcomes with this strategy.

Anesthesia for Combined Heart-Liver Transplantation: A Narrative Review

In 1984, 21 years after the first liver transplantation, Thomas Starzl achieved a milestone by performing the world's first combined heart-liver transplantation. While still uncommon, the practice of combined heart-liver transplants is on the rise globally. In this review, the authors delve into the current literature on this procedure, highlighting the evolving landscape and key considerations for anesthesiologists. Over the years, there has been a remarkable increase in the number of combined heart-liver transplantations conducted worldwide. This surge is largely attributed to the growing population of adult survivors with single-ventricle physiology, palliated with a Fontan procedure, who later present with late Fontan failure and Fontan-associated liver disease. Research indicates that combined heart-liver transplantation is an effective treatment option, with reported outcomes comparable with isolated heart or liver transplants. Managing anesthesia during a combined heart-liver transplant procedure is challenging, especially in the context of underlying Fontan physiology. International experience in this field remains somewhat limited, with most techniques derived from expert opinions or experiences with single-organ heart and liver transplants. These procedures are highly complex and performed infrequently. As the number of combined heart-liver transplants continues to rise globally, there is a growing need for clear guidance on periprocedural surgical and anesthetic management. Anesthesiologists overseeing these patients must consider multiple factors, balancing various comorbidities with significant hemodynamic and metabolic shifts. An increase in (multicenter) studies focusing on specific interventions to enhance patient and organ outcomes is anticipated in the coming years.

The future of liver transplantation

Over the last 50 years, liver transplantation has evolved into a procedure routinely performed in many countries worldwide. Those able to access this therapy frequently experience a miraculous risk-benefit ratio, particularly if they face the imminently life-threatening disease. Over the decades, the success of liver transplantation, with dramatic improvements in early posttransplant survival, has aggressively driven demand. However, despite the emergence of living donors to augment deceased donors as a source of organs, supply has lagged far behind demand. As a result, rationing has been an unfortunate focus in recent decades. Recent shifts in the epidemiology of liver disease combined with transformative innovations in liver preservation suggest that the underlying premise of organ shortage may erode in the foreseeable future. The focus will sharpen on improving equitable access while mitigating constraints related to workforce training, infrastructure for organ recovery and rehabilitation, and their associated costs. Research efforts in liver preservation will undoubtedly blossom with the aim of optimizing both the timing and conditions of transplantation. Coupled with advances in genetic engineering, regenerative biology, and cellular therapies, the portfolio of innovation, both broad and deep, offers the promise that, in the future, liver transplantation will not only be broadly available to those in need but also represent a highly durable life-saving therapy.

Pediatric Combined Heart-liver Transplantation: A Single-center Long-term Experience

Background

Combined heart liver transplant (CHLT) continues to gain attention as a surgical treatment for patients with end-stage heart and liver disease but remains rare. We present our institutional longitudinal experience with up to 14 y of follow-up, focused on long-term outcomes in CHLT recipients.

Methods

We conducted a single-institutional, retrospective review from January 1, 2010, to December 31, 2023, including 7 patients ages 7-17 y who underwent CHLT.

Results

Most patients were surgically palliated via Fontan procedure pretransplant (n = 6), and all had evidence of advanced fibrosis or cirrhosis before transplant. The 30-d mortality was 14.3% (n = 1, multiorgan failure). During the follow-up period, 1 patient developed acute heart rejection which required treatment and 2 developed acute liver rejection. In all cases, rejection was successfully treated. Two patients developed acute heart rejection which did not require treatment (grade 1R). No patients developed chronic or refractory rejection. No patients developed allograft coronary artery vasculopathy.

Conclusions

CHLT remains a rarely performed treatment for pediatric patients with end-stage heart and liver disease, but our long-term data suggest that this treatment strategy should be considered more frequently.

Combined Organ Transplantation in Patients with Advanced Liver Disease

Transplantation of the liver in combination with other organs is an increasingly performed procedure. Over the years, continuous improvement in survival could be realized through careful patient selection and refined organ preservation techniques, in spite of the challenges posed by aging recipients and donors, as well as the increased use of steatotic liver grafts. Herein, we revisit the epidemiology, allocation policies in different transplant zones, indications, and outcomes with regard to simultaneous organ transplants involving the liver, that is combined heart-liver, liver-lung, liver-kidney, and multivisceral transplantation. We address challenges surrounding combined organ transplantation such as equity, utility, and logistics of dual organ implantation, but also advantages that come along with combined transplantation, thereby focusing on molecular mechanisms underlying immunoprotection provided by the liver to the other allografts. In addition, the current standing and knowledge of machine perfusion in combined organ transplantation, mostly based on center experience, will be reviewed. Notwithstanding all the technical advances, shortage of organs, and the lack of universal eligibility criteria for certain multi-organ combinations are hurdles that need to be tackled in the future.

Characteristics and Outcomes of a Single-Centre Cohort of Adult Congenital Heart Disease Patients Referred for Heart Transplant

BACKGROUND

Adult congenital heart disease (ACHD) services increasingly encounter heart failure (HF) in the ageing ACHD population. Optimal timing of referral for heart transplant (HTx) evaluation in this heterogeneous population is complex and ill-defined. We aim to outline the characteristics and outcomes of ACHD patients referred for HTx from a large Australian ACHD centre.

METHOD

Retrospective review of ACHD patients referred for HTx from a primary ACHD centre (1992-2021). Database analysis of patient demographics, characteristics, wait-listing, and transplantation outcomes was performed.

RESULTS

A total of 45 patients (mean age 37±9.9 years old; 69% male) were referred for HTx with a mean follow-up of 5.9±6.3 years. Of these, 22 of 45 (49%) were listed and transplanted, including one heart-lung transplant. The commonest diagnosis was dextro-transposition of the great arteries (13/45, 29%). Most patients, 33 of 45 (73.3%) had undergone at least one cardiac surgery in childhood. Indications for HTx referral included HF in 34 of 45 (75%), followed by pulmonary hypertension in 7 of 45 (11%). Median transplant wait-list time was 145 days (interquartile range, 112-256). Of the 23 patients not wait-listed, the reasons included clinical stability in 13 of 45 (29%), psychosocial factors in 2 of 45 (4.4%) and prohibitive surgical risk, including multiorgan dysfunction, in 8 of 45 (17.7%). Transplant was of a single organ in most, 21 of 22 (95.5%). Overall mortality was 5 of 22 (22.7%) in those after HTx, and 14 of 23 (60.9%) in those not listed (p=0.0156).

CONCLUSIONS

Increasingly, ACHD patients demonstrate the need for advanced HF treatments. HTx decision-making is complex, and increased mortality is seen in those not wait-listed. Ultimately, the referral of ACHD patients for HTx is underpinned by local decision-making and experience, wait-list times and outcomes.

Human liver derived mesenchymal stromal cells ameliorate murine ischemia-induced inflammation through macrophage polarization

Introduction

The immunomodulatory properties of mesenchymal stromal cells (MSC) have been well-characterized in in-vitro and in-vivo models. We have previously shown that liver MSC (L-MSC) are superior inhibitors of T-cell activation/proliferation, NK cell cytolytic function, and macrophage activation compared to adipose (A-MSC) and bone marrow MSC (BM-MSC) in-vitro.

Method

To test these observations in-vivo, we infused these types of MSC into mice with unilateral renal artery stenosis (RAS), an established model of kidney inflammation. Unilateral RAS was induced via laparotomy in 11-week-old, male 129-S1 mice under general anesthesia. Control mice had sham operations. Human L-MSC, AMSC, and BM-MSC (5x105 cells each) or PBS vehicle were injected intra-arterially 2 weeks after surgery. Kidney morphology was studied 2 weeks after infusion using micro-MRI imaging. Renal inflammation, apoptosis, fibrosis, and MSC retention were studied ex-vivo utilizing western blot, immunofluorescence, and immunohistological analyses.

Results

The stenotic kidney volume was smaller in all RAS mice, confirming significant injury, and was improved by infusion of all MSC types. All MSC-infused groups had lower levels of plasma renin and proteinuria compared to untreated RAS. Serum creatinine improved in micetreated with BM- and L-MSC. All types of MSC located to and were retained within the stenotic kidneys, but L-MSC retention was significantly higher than A- and BM-MSC. While all groups of MSC-treated mice displayed reduced overall inflammation and macrophage counts, L-MSC showed superior potency in-vivo at localizing to the site of inflammation and inducing M2 (reparative) macrophage polarization to reduce inflammatory changes.

Discussion

These in-vivo findings extend our in-vitro studies and suggest that L-MSC possess unique anti-inflammatory properties that may play a role in liver-induced tolerance and lend further support to their use as therapeutic agents for diseases with underlying inflammatory pathophysiology.

Incidence and Risk Factors for Stroke After Combined Heart-Kidney and Heart-Liver Transplantation

OBJECTIVE

While stroke is a well-recognized complication of isolated heart transplantation, stroke in patients undergoing simultaneous heart-liver (HLT) and heart-kidney transplantation (HKT) has not been explored. This study assessed postoperative stroke incidence, risk factors, and outcomes in HLT and HKT compared with isolated heart transplant.

METHODS

The United Network for Organ Sharing database was queried for adult patients undergoing HLT, HKT, and isolated heart transplants between 1994 and 2022. Patients were stratified by presence of in-hospital stroke after transplant. Post-transplant survival at 1-year was assessed using Kaplan-Meier analysis and log-rank tests. Separate multivariable logistic regression models were constructed to identify risk factors for stroke after HKT and HLT.

RESULTS

Of 2326 HKT recipients, 85 experienced stroke, and of 442 HLT recipients, 19 experienced stroke. Stroke was more common after HKT and HLT than after an isolated heart transplant (3.7% vs. 4.3% vs. 2.9%, p = 0.01). One-year post-transplant survival was lower in those with stroke among both HKT recipients (64.5% vs. 88.7%, p(log-rank) < 0.001) and HLT recipients (43.8% vs. 87.4%, p(log-rank) < 0.001. Pre-transplant pVAD, prior stroke, postoperative dialysis, diabetes, prior cardiac surgery, and heart cold ischemic time were independent risk factors for stroke after HKT, after adjusting for age, sex, and need for blood transfusion on the waitlist. For HLT, postoperative dialysis was a significant risk factor.

CONCLUSIONS

Stroke is more common after HKT and HLT than after isolated heart transplant, and results in poor survival. Independent risk factors for stroke include pre-transplant percutaneous VAD (HKT) and postoperative dialysis (HKT and HLT).

Review of pediatric combined heart-liver transplantation: A roadmap to success

BACKGROUND

Combined heart-liver transplantation (CHLT) is a promising technique to address end stage organ failure in patients with concomitant heart failure and chronic liver disease. While most experience with CHLT has involved adult patients, the expanding population of children born with univentricular congenital heart disease who underwent the Fontan procedure and develop Fontan-associated liver disease (FALD) has emerged as a growing indication for pediatric CHLT.

METHODS

Currently, CHLT is performed at a select subset of experienced transplant centers, especially in the pediatric population.

RESULTS

While technically demanding, CHLT may offer survival benefit when compared to heart transplant alone with decreased rejection of both synchronous allografts and equivalent outcomes with respect to waitlist time and post-operative complications. Limitations in the technique can be attributed to need for an appropriate multidisciplinary care center, challenges with donor organ availability and allocation, and the complexity associated with patient selection and peri-operative management.

CONCLUSION

In this review, we summarize the history of CHLT, discuss patient selection, and highlight key facets of peri-operative care in the pediatric population.