A critical analysis of early death after adult liver transplants

Invasive Fungal Infections after Liver Transplantation

Invasive fungal infections represent a major challenge in patients who underwent organ transplantation. Overall, the most common fungal infections in these patients are candidiasis, followed by aspergillosis and cryptococcosis, except in lung transplant recipients, where aspergillosis is most common. Several risk factors have been identified, which increase the likelihood of an invasive fungal infection developing after transplantation. Liver transplant recipients constitute a high-risk category for invasive candidiasis and aspergillosis, and therefore targeted prophylaxis is favored in this patient population. Furthermore, a timely implemented therapy is crucial for achieving optimal outcomes in transplanted patients. In this article, we describe the epidemiology, risk factors, prophylaxis, and treatment strategies of the most common fungal infections in organ transplantation, with a focus on liver transplantation.

Incidence of Invasive Fungal Infections in Liver Transplant Recipients under Targeted Echinocandin Prophylaxis

Invasive fungal infections (IFIs) are one of the most important infectious complications after liver transplantation, determining morbidity and mortality. Antimycotic prophylaxis may impede IFI, but a consensus on indication, agent, or duration is still missing. Therefore, this study aimed to investigate the incidence of IFIs under targeted echinocandin antimycotic prophylaxis in adult high-risk liver transplant recipients. We retrospectively reviewed all patients undergoing a deceased donor liver transplantation at the Medical University of Innsbruck in the period from 2017 to 2020. Of 299 patients, 224 met the inclusion criteria. We defined patients as being at high risk for IFI if they had two or more prespecified risk factors and these patients received prophylaxis. In total, 85% (190/224) of the patients were correctly classified according to the developed algorithm, being able to predict an IFI with a sensitivity of 89%. Although 83% (90/109) so defined high-risk recipients received echinocandin prophylaxis, 21% (23/109) still developed an IFI. The multivariate analysis identified the age of the recipient (hazard ratio-HR = 0.97, p = 0.027), split liver transplantation (HR = 5.18, p = 0.014), massive intraoperative blood transfusion (HR = 24.08, p = 0.004), donor-derived infection (HR = 9.70, p < 0.001), and relaparotomy (HR = 4.62, p = 0.003) as variables with increased hazard ratios for an IFI within 90 days. The fungal colonization at baseline, high-urgency transplantation, posttransplant dialysis, bile leak, and early transplantation showed significance only in a univariate model. Notably, 57% (12/21) of the invasive Candida infections were caused by a non-albicans species, entailing a markedly reduced one-year survival. The attributable 90-day mortality rate of an IFI after a liver transplant was 53% (9/17). None of the patients with invasive aspergillosis survived. Despite targeted echinocandin prophylaxis, there is still a notable risk for IFI. Consequently, the prophylactic use of echinocandins must be critically questioned regarding the high rate of breakthrough infections, the increased occurrence of fluconazole-resistant pathogens, and the higher mortality rate in non-albicans Candida species. Adherence to the internal prophylaxis algorithms is of immense importance, bearing in mind the high IFI rates in case algorithms are not followed.

The Need to Update Endpoints and Outcome Analysis in the Rapidly Changing Field of Liver Transplantation

Liver transplantation (LT) survival rates have continued to improve over the last decades, mostly due to the reduction of mortality early after transplantation. The advancement is facilitating a liberalization of access to LT, with more patients with higher risk profiles being added to the waiting list. At the same time, the persisting organ shortage fosters strategies to rescue organs of high-risk donors. This is facilitated by novel technologies such as machine perfusion. Owing to these developments, reconsideration of the current and emerging endpoints for the assessment of the efficacy of existing and new therapies is warranted. While conventional early endpoints in LT have focused on the damage induced to the parenchyma, the fate of the bile duct and the recurrence of the underlying disease have a stronger impact on the long-term outcome. In light of this evolving landscape, we here attempt to reflect on the appropriateness of the currently used endpoints in the field of LT trials.

Early postoperative mortality in liver transplant recipients involving indications other than hepatocellular carcinoma. A retrospective cohort study

AIMS

To analyze the perioperative differences in a consecutive cohort of liver transplant recipients (LTRs) classified according to the indication of transplantation, and assess their impact upon early mortality 90 days after transplantation.

DESIGN

A retrospective cohort study was carried out.

SCOPE

A single university hospital.

PATIENTS

A total of 892 consecutive adult LTRs were included from January 1995 to December 2017. Recipients with acute liver failure, retransplantation or with grafts from non-brain death donors were excluded. Two cohorts were analyzed according to transplant indication: hepatocellular carcinoma (HCC-LTR) versus non-carcinoma (non-HCC-LTR).

MAIN VARIABLES OF INTEREST

Recipient early mortality was the primary endpoint. The pretransplant recipient and donor characteristics, surgical time data and postoperative complications were analyzed as independent predictors.

RESULTS

The crude early postoperative mortality rate related to transplant indication was 13.3% in non-HCC-LTR and 6.6% in HCC-LTR (non-adjusted HR=2.12, 95%CI=1.25-3.60; p=0.005). Comparison of the perioperative features between the cohorts revealed multiple differences. Multivariate analysis showed postoperative shock (HR=2.02, 95%CI=1.26-3.24; p=0.003), early graft vascular complications (HR=4.01, 95%CI=2.45-6.56; p<0.001) and multiorgan dysfunction syndrome (HR=18.09, 95%CI=10.70-30.58; p<0.001) to be independent predictors of mortality. There were no differences in early mortality related to transplant indication (adjusted HR=1.60, 95%CI=0.93-2.76; p=0.086).

CONCLUSIONS

The crude early postoperative mortality rate in non-HCC-LTR was higher than in HCC-LTR, due to a greater incidence of postoperative complications with an impact upon mortality (shock at admission to intensive care and the development of multiorgan dysfunction syndrome).

Extracorporeal Membrane Oxygenation in Pediatric Liver Transplantation: A Multicenter Linked Database Analysis and Systematic Review of the Literature

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) can be used to maintain oxygen delivery and provide hemodynamic support in case of circulatory and respiratory failure. Although the role of ECMO has emerged in the setting of adult liver transplantation (LT), data in children are limited. We aimed to describe the characteristics and outcomes of children receiving ECMO support at the time of or following LT.

METHODS

All pediatric LT recipients (≤20 y) requiring ECMO support peri-/post-LT were identified from a linked Pediatric Health Information System/Scientific Registry of Transplant Recipients dataset (2002-2018). The Kaplan-Meier method and Cox regression analysis were used to assess post-ECMO survival. A systematic literature review was conducted in accordance with the PRISMA statement.

RESULTS

Thirty-four children required ECMO peri-/post-LT. The median time from LT to ECMO was 5 d (interquartile range, 0.0-12.3), and the median ECMO duration was 1 d (interquartile range, 1.0-6.3). Children started on ECMO within 1 d of LT exhibited superior survival compared with those started on ECMO later (P = 0.03). When adjusting for recipient weight, increasing time from LT to ECMO initiation was associated with increased risk of mortality (hazard ratio, 1.03; 95% confidence interval, 1.00-1.06; P = 0.049). Overall, 55.9% (n = 19 of 34) of the patients survived. Twenty-two children receiving ECMO in the peri-/post-LT period were systematically reviewed, and 15 of them survived (68.2%).

CONCLUSIONS

With an encouraging >55% patient survival at 6 mo, ECMO should be considered as a viable option in pediatric LT recipients with potentially reversible severe respiratory or cardiovascular failure refractory to conventional treatment.

Preoperative Stratification of Liver Transplant Recipients: Validation of the LTRS

BACKGROUND

The liver transplant risk score (LTRS) was developed to stratify 90-day mortality of patients referred for liver transplantation (LT). We aimed to validate the LTRS using a new cohort of patients.

METHODS

The LTRS stratifies the risk of 90-day mortality of LT recipients based on their age, body mass index, diabetes, model for end-stage liver disease (MELD) score, and need for dialysis. We assessed the performance of the LTRS using a new cohort of patients transplanted in the United States between July 2013 and June 2017. Exclusion criteria were age <18 years, ABO incompatibility, redo or multivisceral transplants, partial grafts, malignancies other than hepatocellular carcinoma and fulminant hepatitis.

RESULTS

We found a linear correlation between the number of points of the LTRS and 90-day mortality. Among 18 635 recipients, 90-day mortality was 2.7%, 3.8%, 5.2%, 4.8%, 6.7%, and 9.3% for recipients with 0, 1, 2, 3, 4, and ≥5 points (P < 0.001). The LTRS also stratified 1-year mortality that was 5.5%, 7.7%, 9.9%, 9.3%, 10.8%, and 15.4% for 0, 1, 2, 3, 4, and ≥5 points (P < 0.001). An inverse correlation was found between the LTRS and 4-year survival that was 82%, 79%, 78%, 82%, 78%, and 66% for patients with 0, 1, 2, 3, 4, and ≥5 points (P < 0.001). The LTRS remained an independent predictor after accounting for recipient sex, ethnicity, cause of liver disease, donor age, cold ischemia time, and waiting time.

CONCLUSIONS

The LTRS can stratify the short- and long-term outcomes of LT recipients at the time of their evaluations irrespective of their gender, ethnicity, and primary cause of liver disease.

Concurrent Thoracic Endovascular Aortic Repair and Liver Transplant: Multidisciplinary Management of Multiple Posttraumatic Lesions

Association of thoracic and abdominal injuries in patients with major trauma is common. Under emergency conditions, it is often difficult to promptly perform a certain diagnosis and identify treatment priorities of life-threatening lesions. We present the case of a young man with combined thoracic and abdominal injuries after a motorcycle accident. Primary evaluation through echography and X-ray showed fluid within the hepatorenal recess and an enlarged mediastinum. Volume load, blood transfusions, and vasoactive agents were initiated to sustain circulation. Despite hemodynamic instability, we decided to perform computed tomographic angiography (CTA) scan that revealed a high-grade traumatic aortic pseudoaneurysm, multiple and severe areas of liver contusion, and a small amount of hemoperitoneum, without active bleeding spots. The patient was successfully submitted to thoracic endovascular aortic repair (TEVAR). Immediately after the end of the successful TEVAR, signs of massive abdominal bleeding revealed. Immediate explorative laparotomy was performed showing massive hepatic hemorrhage. After liver packing and Pringle's maneuver, control of bleeding was lastly obtained with hemostatic devices and selective cross-clamping of the right hepatic artery. The patient was then transferred to intensive care unit where, despite absence of further hemorrhage, hemodynamic instability, anuria, severe lactic acidosis together with liver necrosis indices appeared. A new CTA demonstrated massive parenchymal disruption within the right lobe of the liver and multiple hematomas in the left lobe. Considering the high-grade lesions of the hepatic vascular tree and liver failure, patient was listed for emergency liver transplantation (LT). LT occurred few hours later, and patient's clinical conditions rapidly improved even if the subsequent clinical course was characterized by a severe fungal infection because of immunosuppression. Evaluation of life-threatening lesions and treatment priorities, availability of different excellence skills, and multidisciplinary collaboration have a key role to achieve clinical success in such severe cases.

Impact of recipient functional status on 1-year liver transplant outcomes

BACKGROUND

The Karnofsky Performance Status (KPS) scale has been widely validated for clinical practice for over 60 years.

AIM

To examine the extent to which poor pre-transplant functional status, assessed using the KPS scale, is associated with increased risk of mortality and/or graft failure at 1-year post-transplantation.

METHODS

This study included 38278 United States adults who underwent first, non-urgent, liver-only transplantation from 2005 to 2014 (Scientific Registry of Transplant Recipients). Functional impairment/disability was categorized as severe, moderate, or none/normal. Analyses were conducted using multivariable-adjusted Cox survival regression models.

RESULTS

The median age was 56 years, 31% were women, median pre-transplant Model for End-Stage for Liver Disease score was 18. Functional impairment was present in 70%; one-quarter of the sample was severely disabled. After controlling for key recipient and donor factors, moderately and severely disabled patients had a 1-year mortality rate of 1.32 [confidence interval (CI): 1.21-1.44] and 1.73 (95%CI: 1.56-1.91) compared to patients with no impairment, respectively. Subjects with moderate and severe disability also had a multivariable-adjusted 1-year graft failure rate of 1.13 (CI: 1.02-1.24) and 1.16 (CI: 1.02-1.31), respectively.

CONCLUSION

Pre-transplant functional status is a useful prognostic indicator for 1-year post-transplant patient and graft survival.

Pretransplant predictors of early mortality in adult recipients of liver transplantation in the MELD-Na Era

AIMS

To identify pretransplant predictors of early mortality (90 days after transplantation) and evaluate their discriminating capacity in adult liver transplant recipients (LTR).

DESIGN

An observational, retrospective, nested cases-controls study from a consecutive cohort of LTRs was carried out.

SETTING

University hospital.

PATIENTS

All consecutive LTR between January 2003 and December 2016 were eligible for inclusion. Patients with acute liver failure, previous graft dysfunction, simultaneous multiple organ transplantation, non-heart beating donors, and those needing urgent retransplantation during the study period were excluded. The analysis comprised 471 patients.

MAIN VARIABLES OF INTEREST

Pretransplant characteristics were the main variables of interest. The LTR were grouped according to the dependent variable (early mortality). Multivariate logistic regression analysis was conducted to identify predictors of early mortality. The discriminating capacity of the models obtained was evaluated by comparing ROC curves (models versus MELD-Na).

RESULTS

The MELD-Na score (OR = 1.069, 95% CI = 1.014-1.127), age > 60 years (OR = 2.479, 95% CI = 1.226-5.015), and LTR height < 163cm (OR = 4.092, 95% CI = 2.115-7.917) were identified as independent predictors of early mortality. The cause of transplantation (hepatocellular carcinoma or decompensated cirrhosis) was identified as a confounding factor.

CONCLUSIONS

In LTR due to decompensated cirrhosis, the MELD-Na score, age > 60 years, and height < 163cm are independent predictors of early mortality. These factors provide a better classification model than the MELD-Na score for early post-transplant mortality.

Functional status predicts postoperative mortality after liver transplantation

BACKGROUND

Frail patients are more vulnerable to perioperative stressors of liver transplantation (LT). Program Specific Reports, used in transplant center auditing, risk-adjust for frailty using the Karnofsky Performance Status (KPS) scale. We evaluate the extent to which functional impairment/disability is associated with increased risk of postoperative death.

METHODS

We included 24 505 first-time LT recipients from the Scientific Registry of Transplant Recipients (2006-2011). We categorized patients as Severe, Moderate, or Normal function/disability using the KPS scale and evaluated risk of 30- and 90-day mortality. Analyses took potential center-specific differences in KPS measurement protocols into account using hierarchal logistic modeling.

RESULTS

Over one-quarter of our population was Severely impaired/disabled, and 30.5% had no functional limitations. Severely and Moderately impaired/disabled patients had 2.56 (95% CI 1.91-3.44) and 1.40 (95% CI 1.10-1.78) times the odds of 30-day mortality, respectively, after adjusting for key recipient and donor factors. Estimates remained consistent regardless of Model for End-Stage Liver Disease score, medical condition, or clustering analyses by center. Technical/operative complications and multiorgan failure/hemorrhage were more common causes of death among more Severely disabled patients than in higher functioning groups.

CONCLUSIONS

Pre-transplant functional status, assessed using the KPS scale, is a reliable predictor of post-LT mortality in the United States.

Liver transplant recipients and prioritization of anti-HCV therapy: an Italian cohort analysis

BACKGROUND AND AIMS

In patients with hepatitis C virus (HCV), recurrence of infection after liver transplant (LT) is universal and associated with worst survival. We present the results of an Italian cohort to compare the 3-year outcome of HCV-Ab-positive and HCV-Ab-negative LT recipients and to assess the potential interaction between HCV-Ab sero-status and other risk factors for LT failure.

METHODS

The study is a multicentre cohort including a sample of liver transplant centres. Participant's information was collected at the local level. The best functional form of variables was decided according to the objective methods based on information theory. Association between transplant failure and potential risk factors was assessed in univariate and multivariate Poisson regression model with random intercept.

RESULTS

Between June 2007 and May 2009, 1164 LT recipients were enrolled in 16 Italian transplant centres, of them 275 (23.63%) experienced LT failure. Incidence rates of LT failure was 0.32 and 0.23 per 1000 person-days in HCV-Ab-positive and HCV-Ab-negative recipients respectively (P = 0.003). Inferential models according to Akaike information criterion indicated that donor-recipient age difference and donor-recipient sex matching were more informative to predict LT failure than the age and the sex as separate variables. Multivariate analysis provided evidence that HCV-Ab sero-status, time after LT, donor-recipient age difference, donor-recipient sex matching and recipient's MELD score were significantly associated with LT failure. Moreover, the effect of HCV-Ab sero-status on LT failure was modified by the simultaneous action of time after LT and donor-recipient age difference. No interaction was found between recipient's HCV-Ab sero-status and either recipient's MELD or donor-recipient sex matching.

CONCLUSION

In view of the imminent introduction of new anti-HCV therapies, our study provides information to assess which LT recipients should be prioritized for receiving these highly effective, but expensive, new treatments. This is particularly relevant for those clinical settings where healthcare prioritization is endorsed by national authorities.

The Correlation of Hepatic and Systemic Hemodynamics During Liver Transplantation: Quantification of Hepatic Resistance as an Actual Value

The correlation between portal vein pressure (PVP) and flow (PVF) has not been established, and there is still lack of consensus about the optimal hemodynamics during liver transplantation (LT). We aimed to establish the correlation between systemic and hepatic hemodynamics during LT by applying the hepatokinetic power hypothesis, based on the law of energy conservation and hydrodynamics.A total of 103 adult liver transplant recipients were enrolled in this study from September 2012 to December 2014. Systemic and hepatic hemodynamics were assessed intraoperatively to calculate the hepatokinetic power status. Severe surgical complications (Clavien-Dindo grade ≥III) were recorded as the main outcome measure, and potential covariates were evaluated including recipient, donor, donor-recipient match, surgery-related factors, conventional hemodynamics, and the intraoperative hepatokinetic power profile.In multivariate analysis, hepatokinetic power gradient >4260 mL mmHg min100 g graft weight (P = 0.001), 2.2 < ratio of hepatokinetic power from the portal vein to the hepatic artery ≤8.7 (P = 0.012), and hepatic resistance of partial grafts ≤0.006 or >0.015 min mmHg mL (P = 0.012) were associated with a higher risk. None of the conventional hemodynamic parameters, such as PVP, PVF, and hepatic venous pressure gradient, entered into this regression model (c-statistic = 0.916) when competing with hepatokinetic power indexes.The hepatokinetic power hypothesis clarifies the correlation of systemic and hepatic hemodynamics in a simple, rational manner. The hepatic resistance, derived from the hepatokinetic power equation, can be quantified and has an effect on the incidence of severe surgical complications. This finding offers a new objective clinical approach to evaluate graft quality during transplantation.