Impact of center volume on outcomes of increased-risk liver transplants

Machine Perfusion Technology Drives a Major Growth Surge in Liver Transplantation

INTRODUCTION

Machine perfusion (MP) opens the possibility to overcome the existing disbalance between supply and demand in liver transplantation. However, it has not been widely adopted across the country. We explored trends of MP adoption in the United States and their effect on center volume (CV).

METHODS

We used the Standard Transplant Analysis and Research datafile from January 2010 to July 2023 to assess CV changes following MP implementation. We classified centers into MP nonusers, low MP users, and high MP (HMP) users. We used interrupted time series analysis to measure changing patterns of HMP CV before and after January 2016, marking the occurrence of the first MP case. High-volume institutions in 2015 were additionally compared to their equivalents in 2022 stratified by their MP status using Wilcoxon rank sum test.

RESULTS

In our controlled interrupted time series, HMP centers had a sustained yet moderate positive trend in volume (P < 0.001). Comparing only high-volume institutions, we found no difference in the number of transplants performed in 2015 to their equivalents in 2022. In the stratified analysis, only HMP centers had a significant increase in the total number of transplants in 2022 (P = 0.032).

CONCLUSIONS

MP has demonstrated to greatly improve outcomes for recipients of liver transplantation. Here, we demonstrate that centers that incorporate MP could potentially benefit from a growth in their practice as well. Further studies are needed to better characterize the features that drive transplant centers to grow across time.

Proposal of a Network System to Solve the Problem of Small Volume in Liver Transplantation; Catholic Medical Center Network

INTRODUCTION

Liver transplantation (LT) is a complex and demanding procedure associated with significant perioperative challenges and risks. Concerns have arisen regarding LT outcomes in low-volume centers. We implemented an integrated training and surgical team network to address these concerns within the Catholic Medical Center (CMC) network. This study presents a comprehensive review of our 9-year LT experience within the CMC medical network.

METHOD

A retrospective study of LT procedures conducted between January 2013 and August 2021 in 6 CMC-affiliated hospitals was performed. One center was categorized as a high-volume center, conducting over 60 cases annually, and the remaining 5 were considered small-volume centers. The primary endpoints assessed were 1-year and 5-year survival rates.

RESULTS

A total of 793 LTs were performed during the study period. The high-volume center performed 411 living donor LT (LDLT) cases and 127 deceased donor LT (DDLT) cases. Also, 146 LDLT cases and 109 DDLT cases were performed in 5 small-volume centers. One-year and 5-year patient survival for LDLT recipients was 88.3% and 78.8% in the high-volume center and 85.6% and 80.6% in the low-volume center. Five-year survival was not significantly different in small-volume centers (P = .903). For DDLT recipients, 1-year and 5-year patient survival was 80.3% and 70.6% in the high-volume center and 76.1% and 67.6% in the low-volume center. In DDLT cases, 5-year survival was not significantly different in small-volume centers (P = .445).

CONCLUSION

In conclusion, comparable outcomes for liver transplantation can be obtained in a small-volume center with a high level of integrated training systems and networks.

Association of Neighborhood Deprivation and Transplant Center Quality with Liver Transplantation Outcomes

BACKGROUND

Social determinants of health can impact the quality of liver transplantation (LT) care. We sought to assess whether the association between neighborhood deprivation and transplant outcomes can be mitigated by receiving care at high-quality transplant centers.

STUDY DESIGN

In this population-based cohort study, patients who underwent LT between 2004 and 2019 were identified in the Scientific Registry of Transplant Recipients. LT-recipient neighborhoods were identified at the county level and stratified into quintiles relative to Area Deprivation Index (ADI). Transplant center quality was based on the Scientific Registry of Transplant Recipients 5-tier ranking using standardized transplant rate ratios. Multivariable Cox regression was used to assess the relationship between ADI, hospital quality, and posttransplant survival.

RESULTS

A total of 41,333 recipients (median age, 57.0 [50.0 to 63.0] years; 27,112 [65.4%] male) met inclusion criteria. Patients residing in the most deprived areas were more likely to have nonalcoholic steatohepatitis, be Black, and travel further distances to reach a transplant center. On multivariable analysis, post-LT long-term mortality was associated with low- vs high-quality transplant centers (hazard ratio [HR] 1.19, 95% CI 1.07 to 1.32), as well as among patients residing in high- vs low-ADI neighborhoods (HR 1.25, 95% CI 1.16 to 1.34; both p ≤ 0.001). Of note, individuals residing in high- vs low-ADI neighborhoods had a higher risk of long-term mortality after treatment at a low-quality (HR 1.31, 95% CI 1.06 to 1.62, p = 0.011) vs high-quality (HR 1.12, 95% CI 0.83 to 1.52, p = 0.471) LT center.

CONCLUSIONS

LT at high-quality centers may be able to mitigate the association between posttransplant survival and neighborhood deprivation. Investments and initiatives that increase access to referrals to high-quality centers for patients residing in higher deprivation may lead to better outcomes and help mitigate disparities in LT.

Simultaneous Heart-Kidney Transplant-Does Hospital Experience With Heart Transplant or Kidney Transplant Have a Greater Impact on Patient Outcomes?

High institutional transplant volume is associated with improved outcomes in isolated heart and kidney transplant. The aim of this study was to assess trends and outcomes of simultaneous heart-kidney transplant (SHKT) nationally, as well as the impact of institutional heart and kidney transplant volume on survival. All adult patients who underwent SHKT between 2005-2019 were identified using the United Network for Organ Sharing (UNOS) database. Annual institutional volumes in single organ transplant were determined. Univariate and multivariable analyses were conducted to assess the impact of demographics, comorbidities, and institutional transplant volumes on 1-year survival. 1564 SHKT were identified, increasing from 54 in 2005 to 221 in 2019. In centers performing SHKT, median annual heart transplant volume was 35.0 (IQR 24.0-56.0) and median annual kidney transplant volume was 166.0 (IQR 89.5-224.0). One-year survival was 88.4%. In multivariable analysis, increasing heart transplant volume, but not kidney transplant volume, was associated with improved 1-year survival. Increasing donor age, dialysis requirement, ischemic times, and bilirubin were also independently associated with reduced 1-year survival. Based on this data, high-volume heart transplant centers may be better equipped with managing SHKT patients than high-volume kidney transplant centers.

Impact of Donation After Circulatory Death Allografts on Outcomes After Liver Transplant for Hepatitis C: A Single-Center Experience and Review of the Literature

OBJECTIVES

We investigated the impact of liver transplant from donors after circulatory death on incidence and severity of recurrent hepatitis C virus infection, graft and patient survival and aimed to identify predictors of outcomes.

MATERIALS AND METHODS

We retrospectively reviewed all liver transplants performed at a single center (July 2007-February 2014). Patients with hepatitis C who underwent liver transplant from donors after circulatory death (group 1) were compared with hepatitis C patients who received grafts from donors after brain death (group 2) and patients without hepatitis C who received grafts from donors after circulatory death (group 3).We used the Kaplan-Meier method for survival analysis and performed a multivariable analysis for predictors of outcomes using Cox regression. Competing risk was used to analyze hepatitis C recurrence.

RESULTS

Of 196 patients, 107 were included: 25 in group 1, 46 in group 2, and 36 in group 3. All 3 groups were comparable, except for longer cold ischemia time (P < .01) in group 1, lower Model for End-Stage Liver Disease score at transplant in groups 1 and 3 (P < .01), and greater proportion of recipients with hepatocellular carcinoma in groups 1 and 2 (P = .02). Hepatitis C recurrence and severe recurrence at 1 and 3 years were higher in group 1 (but not statistically significant). Severe recurrence was noted in 17% versus 8% at 1 year (P = .12) and 30% versus 14% at 3 years (P = .08). Graft and patient survival rates at 1, 3, and 5 years were comparable in all 3 study groups.

CONCLUSIONS

Recurrent hepatitis C, including severe recurrence, was greater following donation after circulatory death compared with donation after brain death liver transplant. However, graft survival and patient survival were comparable, including in recipients of donation after circulatory death grafts without hepatitis C.

Medicaid expansion is associated with a higher likelihood of early diagnosis, resection, transplantation, and overall survival in patients with hepatocellular carcinoma

BACKGROUND

We examined the association between Medicaid expansion (ME) and the diagnosis, treatment, and survival of patients with hepatocellular carcinoma (HCC).

METHODS

We identified patients with HCC <65yrs with Medicaid or without insurance within the National Cancer Database before (2010-2013) or after (2015-2017) ME with early (cT1) or intermediate/advanced (cT2-T4 or M1) disease.

RESULTS

We identified 4848 patients with HCC before and 4526 after ME. Prior to ME, there was no association between future ME status and diagnosis of early HCC (34.5% vs. 32.9%). There was no association between future ME status and treating early HCC with ablation, resection, or transplantation. Patients with early HCC in future ME states were less likely to die (HR = 0.81, 95% CI: 0.67-0.98). After ME, patients in ME states were more likely to be diagnosed with early HCC (39.2% vs. 32.1%). Patients with early disease in ME states were more likely to undergo resection (OR=1.78, 95% CI: 1.16-2.75) or transplantation (OR=3.20, 95% CI: 1.40-7.33). There was a further associated decrease in the hazard of death (HR=0.68, 95% CI: 0.54-0.86).

CONCLUSION

ME was associated with early diagnosis of HCC. For early HCC, ME was associated with increased utilization of resection and transplantation and improvement in survival.

Predictive Value of HAS-BLED Score Regarding Bleeding Events and Graft Survival following Renal Transplantation

Objective: Due to the high prevalence and incidence of cardio- and cerebrovascular diseases among dialysis-dependent patients with end-stage renal disease (ERSD) scheduled for kidney transplantation (KT), the use of antiplatelet therapy (APT) and/or anticoagulant drugs in this patient population is common. However, these patients share a high risk of complications, either due to thromboembolic or bleeding events, which makes adequate peri- and post-transplant anticoagulation management challenging. Predictive clinical models, such as the HAS-BLED score developed for predicting major bleeding events in patients under anticoagulation therapy, could be helpful tools for the optimization of antithrombotic management and could reduce peri- and postoperative morbidity and mortality. Methods: Data from 204 patients undergoing kidney transplantation (KT) between 2011 and 2018 at the University Hospital Leipzig were retrospectively analyzed. Patients were stratified and categorized postoperatively into the prophylaxis group (group A)—patients without pretransplant anticoagulation/antiplatelet therapy and receiving postoperative heparin in prophylactic doses—and into the (sub)therapeutic group (group B)—patients with postoperative continued use of pretransplant antithrombotic medication used (sub)therapeutically. The primary outcome was the incidence of postoperative bleeding events, which was evaluated for a possible association with the use of antithrombotic therapy. Secondary analyses were conducted for the associations of other potential risk factors, specifically the HAS-BLED score, with allograft outcome. Univariate and multivariate logistic regression as well as a Cox proportional hazard model were used to identify risk factors for long-term allograft function, outcome and survival. The calibration and prognostic accuracy of the risk models were evaluated using the Hosmer−Lemshow test (HLT) and the area under the receiver operating characteristic curve (AUC) model. Results: In total, 94 of 204 (47%) patients received (sub)therapeutic antithrombotic therapy after transplantation and 108 (53%) patients received prophylactic antithrombotic therapy. A total of 61 (29%) patients showed signs of postoperative bleeding. The incidence (p < 0.01) and timepoint of bleeding (p < 0.01) varied significantly between the different antithrombotic treatment groups. After applying multivariate analyses, pre-existing cardiovascular disease (CVD) (OR 2.89 (95% CI: 1.02−8.21); p = 0.04), procedure-specific complications (blood loss (OR 1.03 (95% CI: 1.0−1.05); p = 0.014), Clavien−Dindo classification > grade II (OR 1.03 (95% CI: 1.0−1.05); p = 0.018)), HAS-BLED score (OR 1.49 (95% CI: 1.08−2.07); p = 0.018), vit K antagonists (VKA) (OR 5.89 (95% CI: 1.10−31.28); p = 0.037), the combination of APT and therapeutic heparin (OR 5.44 (95% CI: 1.33−22.31); p = 0.018) as well as postoperative therapeutic heparin (OR 3.37 (95% CI: 1.37−8.26); p < 0.01) were independently associated with an increased risk for bleeding. The intraoperative use of heparin, prior antiplatelet therapy and APT in combination with prophylactic heparin was not associated with increased bleeding risk. Higher recipient body mass index (BMI) (OR 0.32 per 10 kg/m2 increase in BMI (95% CI: 0.12−0.91); p = 0.023) as well as living donor KT (OR 0.43 (95% CI: 0.18−0.94); p = 0.036) were associated with a decreased risk for bleeding. Regarding bleeding events and graft failure, the HAS-BLED risk model demonstrated good calibration (bleeding and graft failure: HLT: chi-square: 4.572, p = 0.802, versus chi-square: 6.52, p = 0.18, respectively) and moderate predictive performance (bleeding AUC: 0.72 (0.63−0.79); graft failure: AUC: 0.7 (0.6−0.78)). Conclusions: In our current study, we could demonstrate the HAS-BLED risk score as a helpful tool with acceptable predictive accuracy regarding bleeding events and graft failure following KT. The intensified monitoring and precise stratification/assessment of bleeding risk factors may be helpful in identifying patients at higher risks of bleeding, improved individualized anticoagulation decisions and choices of antithrombotic therapy in order to optimize outcome after kidney transplantation.

The volume - Outcomes relationship in donation after circulatory death liver transplantation

Background

Donation after circulatory death (DCD) liver transplantation (LT) has become an effective mechanism for expanding the donor pool and decreasing waitlist mortality. However, it is unclear if low‐volume DCD centers can achieve comparable outcomes to high‐volume centers.

Methods

From 2011 to 2019 utilizing the United Network for Organ Sharing (UNOS) database, liver transplant centers were categorized into tertiles based on their annual volume of DCD LTs. Donor selection, recipient selection, and survival outcomes were compared between very‐low volume (VLV, n = 1–2 DCD LTs per year), low‐volume (LV, n = 3–5), and high‐volume (HV, n > 5) centers.

Results

One hundred and ten centers performed 3273 DCD LTs. VLV‐centers performed 339 (10.4%), LV‐centers performed 627 (19.2%), and HV‐centers performed 2307 (70.4%) LTs. 30‐day, 90‐day, and 1‐year patient and graft survival were significantly increased at HV‐centers (all P < .05). Recipients at HV‐centers had shorter waitlist durations (P < .01) and shorter hospital lengths of stay (P < .01). On multivariable regression, undergoing DCD LT at a VLV‐center or LV‐center was associated with increased 1‐year patient mortality (VLV‐OR:1.73, 1.12–2.69) (LV‐OR: 1.42, 1.01–2.00) and 1‐year graft failure (VLV‐OR: 1.79, 1.24–2.58) (LV‐OR: 1.28, .95–1.72).

Discussion

Increased annual DCD liver transplant volume is associated with improved patient and graft survival.

Determinants of short-term outcomes after pediatric liver transplantation: a single centre experience over 20 years

BACKGROUND

Liver transplantation (LT) is a standard-of-care therapeutic modality for selected patients with life-threatening liver disease, including children. In addition to specific clinical characteristics of pediatric LT recipients due to initial liver disease (and related comorbidities) and level of liver failure, early postoperative outcome may be dependent on the surgical technique used, related to the type of organ donor and graft. Therefore, the aims of the present retrospective study from a large single centre cohort were to identify the prognostic factors for both 1-year patient and graft survival.

METHODS

Between October 1990 and October 2010, 151 children underwent a first LT in our centre.

RESULTS

The mean age was 5.3 ± 7.4 years, and the main indication was biliary atresia (BA) (49.0%). Living donor liver transplantation (LDLT) was performed in 39 cases (25.8%). Cadaveric liver graft was a whole liver in 50 cases (33.1%) and a partial liver (reduced or split) in 62 cases (41.1%). One-year patient and graft survival rates were 88.7% and 86.1%, respectively. Multivariate analysis disclosed that initial liver disease, location at time of LT, donor/recipient (D/R) delta age, early post-transplant hemodialysis and initial immunosuppression (induction) were significantly associated with patient survival and that D/R delta age, primary non-function, early post-transplant hemodialysis and initial immunosuppression (induction) were significantly associated with graft survival.

CONCLUSION

The results of our single-centre experience of pediatric LT emphasize that early patient and graft survivals depend on pre-operative/operative factors such as initial liver disease, D/R delta age and immunosuppressive regimen. Awareness of these factors can help in the decision making for children requiring LT.

Reexamining Risk Aversion: Willingness to Pursue and Utilize Nonideal Donor Livers Among US Donation Service Areas

Background

Livers from "nonideal" but acceptable donors are underutilized; however, organ procurement organization (OPO) metrics do not assess how OPO-specific practices contribute to these trends. In this analysis, we evaluated nonideal liver donor avoidance or risk aversion among OPOs and within US donation service areas (DSAs).

Methods

Adult donors in the United Network for Organ Sharing registry who donated ≥1 organ for transplantation between 2007 and 2019 were included. Nonideal donors were defined by any of the following: age > 70, hepatitis C seropositive, body mass index > 40, donation after circulatory death, or history of malignancy. OPO-specific performance was evaluated based on rates of nonideal donor pursuit and consent attainment. DSA performance (OPO + transplant centers) was evaluated based on rates of nonideal donor pursuit, consent attainment, liver recovery, and transplantation. Lower rates were considered to represent increased donor avoidance or increased risk aversion.

Results

Of 97 911 donors, 31 799 (32.5%) were nonideal. Unadjusted OPO-level rates of nonideal donor pursuit ranged from 88% to 100%. In a 5-tier system of overall risk aversion, tier 5 DSAs (least risk-averse) and tier 1 DSAs (most risk-averse) had the highest and lowest respective rates of non-ideal donor pursuit, consent attainment, liver recovery, and transplantation. On average, recovery rates were over 25% higher among tier 5 versus tier 1 DSAs. If tier 1 DSAs had achieved the same average liver recovery rate as tier 5 DSAs, approximately 2100 additional livers could have been recovered during the study period.

Conclusion

Most OPOs aggressively pursue nonideal liver donors; however, recovery practices vary widely among DSAs. Fair OPO evaluations should consider early donation process stages to best disentangle OPO and center-level practices.

Liver Transplant Center Size and The Impact on the Clinical Outcomes and Resource Utilization

BACKGROUND

Prior studies suggest that transplant center volume is associated with liver transplantation (LT) outcomes. We compared patient characteristics and waitlist outcomes among transplant centers in the U.S. with different volumes.

METHODS

Data for adult waitlisted candidates and LT recipients in the U.S. between 2008 and 2017 were extracted from the Scientific Registry of Transplant Recipients database. Transplant centers were categorized by transplants/year into tertiles:low-volume centers (LVCs; <20 transplantations per year)medium-volume centers (MVCs; 20-55 transplantations per year)high-volume centers (HVCs; >55 transplantations per year)Patient characteristics, waitlist outcomes, and factors associated with post-transplantation mortality were compared.

RESULTS

From 141 centers, 112,110 patients were waitlisted for LT: 6% at LVCs, 26% at MVCs, and 68% at HVCs. Patients listed in LVCs were less likely to have private insurance but had higher Medicaid and Veterans Affairs healthcare rates. Patients at LVCs were less likely to receive LT (47% vs. 53% in MVC vs. 61% in HVC), had higher transfer rates to other centers, and were more likely to be removed from the waitlist. In competing risk survival analysis, adjusted for center location, MELD score, and clinico-demographic factors, patients listed at an HVC were more likely to receive LT (aHR:1.30; 95%CI= 1.27-1.33; P<0.001). Among LT-recipients (n=62,131), receiving a transplant at an LVC was associated with higher post-LT mortality (aHR:1.16; 95%CI=1.05-1.28; P=0.003).

CONCLUSION

Patients in LVCs were less likely to receive a LT and a higher risk of post-LT death.Supplemental Visual Abstract; http://links.lww.com/TP/C274.

Pediatric discard risk index for predicting pediatric liver allograft discard

BACKGROUND

Of the 600 pediatric candidates added to the liver waiting list annually, 100 will remain waiting while over 100 liver allografts are discarded, often for subjective reasons.

METHODS

We created a risk index to predict discard to better optimize donor supply. We used the UNOS database to retrospectively analyze 17 367 deceased donors (≤18 years old) through univariate and multivariate logistic regression models. Deceased donor clinical characteristics and laboratory values were independent variables with discard being the dependent variable in the analysis. Significant univariate factors (P-value < .05) comprised the multivariate analysis. Significant variables from the multivariate analysis were incorporated into the pDSRI, producing a risk score for discard.

RESULTS

From 17 potential factors, 11 were identified as significant predictors (P < .05) of pediatric liver allograft discard. The most significant risk factors were as follows: DCD; total bilirubin >10 mg/dL, and alanine transaminase (ALT) ≥500 IU/L. The pDSRI has a C-statistic of 0.846 for the training set and 0.840 for the validation set.

CONCLUSION

The pDSRI uses 11 significant risk factors, including elevated liver function tests, donor demographics, and donor risk/type to accurately predict risk of pediatric liver allograft discard and serve as a tool that may maximize donor yield.

Prognostic role of the Donor Risk Index, the Eurotransplant Donor Risk Index, and the Balance of Risk score on graft loss after liver transplantation

This study aimed to identify cutoff values for donor risk index (DRI), Eurotransplant (ET)-DRI, and balance of risk (BAR) scores that predict the risk of liver graft loss. MEDLINE and Web of Science databases were searched systematically and unrestrictedly. Graft loss odds ratios and 95% confidence intervals were assessed by meta-analyses using Mantel-Haenszel tests with a random-effects model. Cutoff values for predicting graft loss at 3 months, 1 year, and 3 years were analyzed for each of the scores. Measures of calibration and discrimination used in studies validating the DRI and the ET-DRI were summarized. DRI ≥ 1.4 (six studies, n = 35 580 patients) and ET-DRI ≥ 1.4 (four studies, n = 11 666 patients) were associated with the highest risk of graft loss at all time points. BAR > 18 was associated with the highest risk of 3-month and 1-year graft loss (n = 6499 patients). A DRI cutoff of 1.8 and an ET-DRI cutoff of 1.7 were estimated using a summary receiver operator characteristic curve, but the sensitivity and specificity of these cutoff values were low. A DRI and ET-DRI score ≥ 1.4 and a BAR score > 18 have a negative influence on graft survival, but these cutoff values are not well suited for predicting graft loss.

Variation in Racial Disparities in Liver Transplant Outcomes Across Transplant Centers in the United States

Little is known about the role that transplant centers may play in perpetuating racial disparities after liver transplantation, which are unexplained by patient-level factors. We examined variation in between-center and within-center disparities among 34,114 Black and White liver transplant recipients in the United States from 2010 to 2017 using Scientific Registry of Transplant Recipient (SRTR) data. We used Cox proportional hazards models to calculate transplant center-specific Black-White hazard ratios and hierarchical survival analysis to examine potential effect modification of the race-survival association by transplant center characteristics, including transplant volume, proportion of Black patients, SRTR quality rating, and region. Models were sequentially adjusted for clinical, socioeconomic, and center characteristics. After adjustment, Black patients experienced 1.11 excess deaths after liver transplant per 100 person-years compared with White patients (95% confidence interval [CI], 0.65-1.56), corresponding to a 21% increased mortality risk (95% CI, 1.12-1.31). Although there was substantial variation in this disparity across transplant centers, there was no evidence of effect modification by transplant center volume, proportion of minority patients seen, quality rating, or region. We found significant racial disparities in survival after transplant, with substantial variation in this disparity across transplant centers that was not explained by selected center characteristics. This is the first study to directly evaluate the role transplant centers play in racial disparities in transplant outcomes. Further assessment of the qualitative factors that may drive disparities, such as selection processes and follow-up care, is needed to create effective center-level interventions to address health inequity.

Transplant center experience influences spontaneous survival and waitlist mortality in acute liver failure: An analysis of the UNOS database

Transplant centers coordinate complex care in acute liver failure (ALF), for which liver transplant (LT) can be lifesaving. We studied associations between waitlist outcomes and center (1) ALF waitlist volume (low: <20; medium: 20-39; high: 40+ listings) and (2) total LT volume (<600, 600-1199, 1200+ LTs) in a retrospective cohort of 3248 adults with ALF listed for LT at 92 centers nationally from 2002 to 2019. Predicted outcome probabilities (LT, died/too sick, spontaneous survival [SS]) were obtained with multinomial regression, and observed-to-expected ratios were calculated. Median center outcome rates were 72.6% LT, 18.2% died/too sick, and 6.1% SS. SS was significantly higher with greater center ALF volume (median 0% for low-, 5.9% for medium-, and 8.6% for high-volume centers; P = .039), while waitlist mortality was highest at low-volume centers (median 21.4%, IQR: 16.1%-26.7%; P = .042). Significant heterogeneity in center performance was observed for waitlist mortality (observed-to-expected ratio range: 0-4.1) and particularly for SS (0-6.4), which persisted despite accounting for recipient case mix. This novel study demonstrates that increased center experience is associated with greater SS and reduced waitlist mortality for ALF. More-focused management pathways are needed to improve ALF outcomes at less-experienced centers and to identify opportunities for improvement at large.

Thirty-day readmission rates, trends and its impact on liver transplantation recipients: a national analysis

Reduction of early hospital readmissions is a declared goal in the United States economic and quality improvement agenda. A retrospective study was performed using the Nationwide Readmissions Database from 2010 to 2014. Our primary aim was to study the rate of early readmissions and its predictors in liver transplant recipients (LTRs). Our secondary aims were to determine the trends of LT, reasons for readmission, costs and predictors of calendar year mortality. Multivariable logistic regression and Cox proportional hazards models were utilized. The 30-day readmission rate was 30.6% among a total of 25,054 LTRs. Trends of LT were observed to be increased in patients > 65 years (11.7-17.8%, p < 0.001) and decreased in 40-64 years (78.0-73.5%, p = 0.001) during study period. The majority of 30-day readmissions were due to post transplant complications, with packed red blood cell transfusions being the most common intervention during readmission. Medicaid or Medicare insurance, surgery at low and medium volume centers, infections, hemodialysis, liver biopsy, and length of stay > 10 days were the predictors of 30-day readmission. Moreover, number of early readmission, age > 64 years, non-alcoholic cirrhosis, and length of stay > 10 days were significant predictor of calendar year mortality in LTRs. Approximately one third of patients require early admission after LT. Early readmission not only increases burden on healthcare, but is also associated with calendar year mortality. Strategies should be implemented to reduce readmission in patients with high risk of readmission identified in our study.

The role of the comprehensive complication index for the prediction of survival after liver transplantation

In the last years, several scoring systems based on pre- and post-transplant parameters have been developed to predict early post-LT graft function. However, some of them showed poor diagnostic abilities. This study aims to evaluate the role of the comprehensive complication index (CCI) as a useful scoring system for accurately predicting 90-day and 1-year graft loss after liver transplantation. A training set (n = 1262) and a validation set (n = 520) were obtained. The study was registered at https://www.ClinicalTrials.gov (ID: NCT03723317). CCI exhibited the best diagnostic performance for 90 days in the training (AUC = 0.94; p < 0.001) and Validation Sets (AUC = 0.77; p < 0.001) when compared to the BAR, D-MELD, MELD, and EAD scores. The cut-off value of 47.3 (third quartile) showed a diagnostic odds ratio of 48.3 and 7.0 in the two sets, respectively. As for 1-year graft loss, CCI showed good performances in the training (AUC = 0.88; p < 0.001) and validation sets (AUC = 0.75; p < 0.001). The threshold of 47.3 showed a diagnostic odds ratio of 21.0 and 5.4 in the two sets, respectively. All the other tested scores always showed AUCs < 0.70 in both the sets. CCI showed a good stratification ability in terms of graft loss rates in both the sets (log-rank p < 0.001). In the patients exceeding the CCI ninth decile, 1-year graft survival rates were only 0.7% and 23.1% in training and validation sets, respectively. CCI shows a very good diagnostic power for 90-day and 1-year graft loss in different sets of patients, indicating better accuracy with respect to other pre- and post-LT scores.Clinical Trial Notification: NCT03723317.

Long-term outcomes after liver transplantation in the Hispanic population

BACKGROUND & AIMS

Racial/ethnic disparities in liver transplantation (LT) are well-recognized. Although Hispanics represent the largest and youngest minority group in the United States, limited data exist on long-term outcomes. We aimed to investigate long-term post-liver transplant outcomes in Hispanic patients and identify potential disparities compared to a baseline demographic of non-Hispanic white patients.

METHODS

We performed a retrospective cohort study of first-time liver transplant recipients using the United Network for Organ Sharing database from 2002 to 2013, with follow-up through 2018. The primary outcomes of interest were overall patient and graft survival after LT.

RESULTS

45 767 patients underwent LT (85.0% non-Hispanic white, 15.0% Hispanic). Hispanics had lower socioeconomic status, higher prevalence of pretransplant comorbidities and more severe liver disease compared to non-Hispanic whites. Hispanics had similar patient (76.6% vs 75.6%; P = .12) and graft (71.7% vs 70.8%; P = .28) survival at 5 years and significantly better patient (62.9% vs 59.7%; P < .001) and graft (58.6% vs 55.6%; P = .002) survival at 10 years. In multivariable analysis, Hispanics had lower associated all-cause mortality (HR 0.86, 95% CI, 0.82-0.91; P < .001) and graft failure (HR 0.89, 95% CI, 0.85-0.93; P < .001) compared to non-Hispanic whites. In etiology-specific subanalysis, Hispanics transplanted for ALD, NASH and HCV had lower all-cause mortality compared to non-Hispanic whites.

CONCLUSIONS

Hispanics have similar or better long-term post-LT outcomes compared to non-Hispanic whites despite a worse pretransplant risk factor profile. Further research is needed to clarify if this survival advantage reflects uncaptured protective factors or more stringent transplant selection in the Hispanic population.

Transcriptional changes during hepatic ischemia-reperfusion in the rat

There are few effective targeted strategies to reduce hepatic ischemia-reperfusion (IR) injury, a contributor to poor outcomes in liver transplantation recipients. It has been proposed that IR injury is driven by the generation of reactive oxygen species (ROS). However, recent studies implicate other mediators of the injury response, including mitochondrial metabolic dysfunction. We examined changes in global gene expression after transient hepatic ischemia and at several early reperfusion times to identify potential targets that could be used to protect against IR injury. Male Wistar rats were subjected to 30 minutes of 70% partial warm ischemia followed by 0, 0.5, 2, or 6 hours of reperfusion. RNA was extracted from the reperfused and non-ischemic lobes at each time point for microarray analysis. Identification of differentially expressed genes and pathway analysis were used to characterize IR-induced changes in the hepatic transcriptome. Changes in the reperfused lobes were specific to the various reperfusion times. We made the unexpected observation that many of these changes were also present in tissue from the paired non-ischemic lobes. However, the earliest reperfusion time, 30 minutes, showed a marked increase in the expression of a set of immediate-early genes (c-Fos, c-Jun, Atf3, Egr1) that was exclusive to the reperfused lobe. We interpreted these results as indicating that this early response represented a tissue autonomous response to reperfusion. In contrast, the changes that occurred in both the reperfused and non-ischemic lobes were interpreted as indicating a non-autonomous response resulting from hemodynamic changes and/or circulating factors. These tissue autonomous and non-autonomous responses may serve as targets to ameliorate IR injury.

Liver Transplantation with "Hors Tour" Allocated Versus Standard MELD Allocated Grafts: Single-Center Audit and Impact on the Liver Pool in France

BACKGROUND

The French transplant governing system defined "Rescue" (the so-called "Hors Tour") livers as those livers which were declined for the five top-listed patients. This study compares the outcomes following liver transplantation (LT) in patients who received a donor liver through a rescue allocation (RA) procedure or according to MELD score priority (standard allocation, SA) and evaluates the impact on the graft pool of a proactive policy to accept RA grafts.

METHODS

Data from all consecutive patients who underwent LT with SA or RA grafts from 2011 to 2015 were compared in terms of short- and long-term outcomes.

RESULTS

The 249 elective first LTs were performed with 64 (25.7%) RA and 185 (74.3%) SA grafts. RA grafts were obtained from older donors and were associated with a longer cold ischemia time. Recipients of RA livers were older and had lower MELD scores. The rates of delayed graft function, primary nonfunction, retransplantation, complications, and mortality were similar between the RA and SA groups. At 1 and 3 and 5 years, graft and patient survival rates were similar between the groups. These results were maintained after matching on recipient characteristics. Our proactive policy to accept RA grafts increased the liver pool for elective first transplantation by 25%.

CONCLUSIONS

RA livers can be safely transplanted into selected recipients and significantly expand the liver pool.

Exploring pre-surgery donor-specific antibodies in the context of organ shortage in liver transplant

BACKGROUND

There is a growing disparity between the number of liver transplant (LT) candidates and availability of suitable liver allografts. Antibody-mediated rejection (AMR), secondary to positive donor-specific antibodies (DSA), remains a concern in liver transplantation. This study aimed to correlate expression of DSA on pre-transplant screening and outcomes of LT, specifically development of AMR in liver allografts and liver function profile in the post-operative period.

METHODS

Data of consecutive patients undergoing orthotopic LT (OLT) at the South Australian Liver Transplant Unit was analysed. All patients underwent DSA testing pre-transplant.

RESULTS

Within a cohort of 96 patients, over a post-OLT median follow-up of 849 days, only 2 patients (2%) developed AMR. While both patients had a positive DSA test preoperatively, overall DSA positivity was noted in 31% patients, with a specificity for prediction of AMR of 0.708. No significant association was noted between AMR (p = 0.092), T cell-mediated rejection/TCMR (p = 0.797) or late hepatic artery thrombosis/LHAT (p = 0.521). There was no significant interaction effect between DSA positivity and serum bilirubin or transaminases over a period of 100 days.

CONCLUSION

AMR following LT is uncommon. A positive DSA pre-transplant does not imply a definite risk of AMR. Also, there does not exist a significant interaction in time between DSA expression and serum bilirubin or transaminase levels. Until there emerges evidence to the contrary, it appears reasonable to consider DSA-positive donors within the broad context of marginal donors in the context of a worldwide shortage of LT donor allografts.

Effect of Institutional Case Volume on In-hospital Mortality After Living Donor Liver Transplantation: Analysis of 7073 Cases Between 2007 and 2016 in Korea

BACKGROUND

The relationship between institutional case volume and clinical outcomes after living donor liver transplantation is not clarified.

METHODS

We conducted a nationwide retrospective cohort study using the database of Korean National Healthcare Insurance Service. Between January 2007 and December 2016, 7073 adult living donor liver transplantations were performed at 50 centers in Korea. Centers were categorized according to the average annual number of liver transplantations: >50, 10 to 50, and <10.

RESULTS

In-hospital mortality rates in the high-, medium-, and low-volume centers were 2.8%, 4.1%, and 6.7%, respectively. After adjustment, in-hospital mortality was significantly higher in low-volume centers (adjusted odds ratio, 2.287; 95% confidence interval, 1.471-3.557; P < 0.001) and medium-volume centers (adjusted odds ratio, 1.676; 95% confidence interval, 1.089-2.578; P = 0.019) compared with high-volume centers. Long-term survival for up to 9 years was better, and intensive care unit and hospital length of stay were shorter in high-volume centers.

CONCLUSIONS

Centers with higher case volume (>50 liver transplantations/year) had better outcomes after living donor liver transplantation, including in-hospital mortality and long-term mortality compared with centers with lower case volume (≤50 liver transplantations/year).

Clinical Implications of Donor Warm and Cold Ischemia Time in Donor After Circulatory Death Liver Transplantation

The use of donation after circulatory death (DCD) liver allografts has been constrained by limitations in the duration of donor warm ischemia time (DWIT), donor agonal time (DAT), and cold ischemia time (CIT). The purpose of this study is to assess the impact of longer DWIT, DAT, and CIT on graft survival and other outcomes in DCD liver transplants. The Scientific Registry of Transplant Recipients was queried for adult liver transplants from DCD donors between 2009 and 2015. Donor, recipient, and center variables were included in the analysis. During the study period, 2107 patients underwent liver transplant with DCD allografts. In most patients, DWIT and DAT were <30 minutes. DWIT was <30 minutes in 1804 donors, between 30 and 40 minutes in 248, and >40 minutes in 37. There was no difference in graft survival, duration of posttransplant hospital length of stay, and readmission rate between DCD liver transplants from donors with DWIT <30 minutes and DWIT between 30 and 40 minutes. Similar outcomes were noted for DAT. In the multivariate analysis, DAT and DWIT were not associated with graft loss. The predictors associated with graft loss were donor age, donor sharing, CIT, recipient admission to the intensive care unit, recipient ventilator dependence, Model for End-Stage Liver Disease score, and low-volume transplant centers. Any CIT cutoff >4 hours was associated with increased risk for graft loss. Longer CIT was also associated with a longer posttransplant hospital stay, higher rate of primary nonfunction, and hyperbilirubinemia. In conclusion, slightly longer DAT and DWIT (up to 40 minutes) were not associated with graft loss, longer posttransplant hospitalization, or hospital readmissions, whereas longer CIT was associated with worse outcomes after DCD liver transplants.

A survey of the anesthetic management of pediatric kidney transplantation in France

BACKGROUND

Renal transplantation is the best available therapeutic option for end-stage renal failure in both children and adults. However, little is known about anesthetic practice during pediatric renal transplantation.

MATERIAL AND METHODS

The study consisted of a national survey about anesthetic practice during pediatric renal transplantation in France. French tertiary pediatric centers performing renal transplants were targeted, and one physician from each team was asked to complete the survey. The survey included patient data, preoperative assessment and optimization data, and intraoperative anesthesia data (drugs, ventilation, and hemodynamic interventions).

RESULTS

Twenty centers performing kidney transplantation were identified and contacted to complete the survey, and eight responded. Surveyed centers performed 96 of the 122 pediatric kidney transplantations performed in France in 2017 (79%). Centers consistently performed echocardiography and ultrasound examinations of the great veins preoperatively and consistently employed esophageal Doppler cardiac output estimation and vasopressors intraoperatively. All other practices were found to be heterogeneous. Central venous pressure was monitored in six centers, and dopamine was administered perioperatively in two centers.

CONCLUSIONS

The current study provides a snapshot of the perioperative management of pediatric kidney transplantation in France. Results emphasize the need for both standardization of practice and awareness of recent evidence against the use of CVP monitoring and dopamine infusions.

The Volume-outcome Relationship in Deceased Donor Kidney Transplantation and Implications for Regionalization

OBJECTIVE

The aim of this study was to investigate the volume-outcome relationship in kidney transplantation by examining graft and patient outcomes using standardized risk adjustment (observed-to-expected outcomes). A secondary objective was to examine the geographic proximity of low, medium, and high-volume kidney transplant centers in the United States.

SUMMARY OF BACKGROUND DATA

The significant survival benefit of kidney transplantation in the context of a severe shortage of donor organs mandates strategies to optimize outcomes. Unlike for other solid organ transplants, the relationship between surgical volume and kidney transplant outcomes has not been clearly established.

METHODS

The Scientific Registry of Transplant Recipients was used to examine national outcomes for adults undergoing deceased donor kidney transplantation from January 1, 1999 to December 31, 2013 (15-year study period). Observed-to-expected rates of graft loss and patient death were compared for low, medium, and high-volume centers. The geographic proximity of low-volume centers to higher volume centers was determined to assess the impact of regionalization on patient travel burden.

RESULTS

A total of 206,179 procedures were analyzed. Compared with low-volume centers, high-volume centers had significantly lower observed-to-expected rates of 1-month graft loss (0.93 vs 1.18, P<0.001), 1-year graft loss (0.97 vs 1.12, P<0.001), 1-month patient death (0.90 vs 1.29, P=0.005), and 1-year patient death (0.95 vs 1.15, P=0.001). Low-volume centers were frequently in close proximity to higher volume centers, with a median distance of 7 miles (interquartile range: 2 to 75).

CONCLUSIONS

A robust volume-outcome relationship was observed for deceased donor kidney transplantation, and low-volume centers are frequently in close proximity to higher volume centers. Increased regionalization could improve outcomes, but should be considered carefully in light of the potential negative impact on transplant volume and access to care.

Association of Kidney Transplant Center Volume With 3-Year Clinical Outcomes

RATIONALE & OBJECTIVE

A robust relationship between procedure volume and clinical outcomes has been demonstrated across many surgical fields. This study assessed whether a center volume-outcome relationship exists for contemporary kidney transplantation, specifically for diabetic recipients, older recipients (aged ≥65 years), and recipients of high kidney donor profile index (KDPI ≥ 85) kidneys.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Adult kidney-only transplant recipients who underwent transplantation between 2009 and 2013 (N = 79,581).

EXPOSURES

The primary exposure variable was center volume, categorized into quartiles based on the total kidney transplantation volume. Quartile 1 (Q1) centers performed a mean of fewer than 66 kidney transplantations per year, whereas Q4 centers performed a mean of more than 196 kidney transplantations per year.

OUTCOMES

All-cause graft failure and mortality within 3 years of transplantation.

ANALYTICAL APPROACH

Multivariable Cox frailty models were used to adjust for donor characteristics, recipient characteristics, and cold ischemia time.

RESULTS

Minor differences in rates of 3-year deceased donor all-cause graft failure across quartiles of center volume were observed (14.9% for Q1 vs 16.7% for Q4), including in subgroups (diabetic recipients, 18.4% for Q1 vs 19.7% for Q4; older recipients, 19.4% for Q1 vs 22.5% for Q4; recipients of high KDPI kidneys, 26.5% for Q1 vs 26.5% for Q4). Results were similar for 3-year mortality. After adjustment for donor, recipient, and graft characteristics using Cox regression, center volume was not significantly associated with all-cause graft failure or mortality within 3 years, except that diabetic recipients at Q3 centers had slightly lower mortality (compared with Q1 centers, adjusted HR of 0.85 [95% CI, 0.73-0.99]).

LIMITATIONS

Potential unmeasured confounding from patient comorbid conditions and organ selection.

CONCLUSIONS

These findings provide little evidence that care in higher volume centers is associated with better adjusted outcomes for kidney transplant recipients, even in populations anticipated to be at increased risk for graft failure or death.

Offer acceptance practices and geographic variability in allocation model for end-stage liver disease at transplant

Offer acceptance practices may cause geographic variability in allocation Model for End-Stage Liver Disease (aMELD) score at transplant and could magnify the effect of donor supply and demand on aMELD variability. To evaluate these issues, offer acceptance practices of liver transplant programs and donation service areas (DSAs) were estimated using offers of livers from donors recovered between January 1, 2016, and December 31, 2016. Offer acceptance practices were compared with liver yield, local placement of transplanted livers, donor supply and demand, and aMELD at transplant. Offer acceptance was associated with liver yield (odds ratio, 1.32; P < 0.001), local placement of transplanted livers (odds ratio, 1.34; P < 0.001), and aMELD at transplant (average aMELD difference, -1.62; P < 0.001). However, the ratio of donated livers to listed candidates in a DSA (ie, donor-to-candidate ratio) was associated with median aMELD at transplant (r = -0.45; P < 0.001), but not with offer acceptance (r = 0.09; P = 0.50). Additionally, the association between DSA-level donor-to-candidate ratios and aMELD at transplant did not change after adjustment for offer acceptance. The average squared difference in median aMELD at transplant across DSAs was 24.6; removing the effect of donor-to-candidate ratios reduced the average squared differences more than removing the effect of program-level offer acceptance (33% and 15% reduction, respectively). Offer acceptance practices and donor-to-candidate ratios independently contributed to geographic variability in aMELD at transplant. Thus, neither offer acceptance nor donor-to-candidate ratios can explain all of the geographic variability in aMELD at transplant. Liver Transplantation 24 478-487 2018 AASLD.

Cost of achieving equivalent outcomes in sicker patients after liver transplant

BACKGROUND

We aimed to characterize variability in cost after straightforward orthotopic liver transplant (OLT).

METHODS

Using the University HealthSystem Consortium and Scientific Registry of Transplant Recipients databases, we identified patients who underwent OLT between 2011 and 2014. Patients meeting criteria for straightforward OLT, defined as length of stay < 14 days with discharge to home, were selected (n = 5763) and grouped into tertiles (low, medium, high) according to cost of perioperative stay.

RESULTS

Patients undergoing straightforward OLT were of similar demographics regardless of cost. High cost patients were more likely to require preoperative hemodialysis, had higher severity of illness, and higher model for end-stage liver disease (MELD) (p < 0.01). High cost patients required greater utilization of resources including lab tests, blood transfusions, and opioids (p < 0.01). Despite having higher burden of disease and requiring increased resource utilization, high cost OLT patients with a straightforward perioperative course were shown to have identical 2-year graft and overall survival compared to lower cost patients (p = 0.82 and p = 0.63), respectively.

CONCLUSION

Providing adequate perioperative care for OLT patients with higher severity of illness and disease burden requires increased cost and resource utilization; however, doing so provides these patients with long term survival equivalent to more routine patients.

Effect of transplant center volume on post-transplant survival in patients listed for simultaneous liver and kidney transplantation

AIM

To examine the effect of center size on survival differences between simultaneous liver kidney transplantation (SLKT) and liver transplantation alone (LTA) in SLKT-listed patients.

METHODS

The United Network of Organ Sharing database was queried for patients ≥ 18 years of age listed for SLKT between February 2002 and December 2015. Post-transplant survival was evaluated using stratified Cox regression with interaction between transplant type (LTA vs SLKT) and center volume.

RESULTS

During the study period, 393 of 4580 patients (9%) listed for SLKT underwent a LTA. Overall mortality was higher among LTA recipients (180/393, 46%) than SLKT recipients (1107/4187, 26%). The Cox model predicted a significant survival disadvantage for patients receiving LTA vs SLKT [hazard ratio, hazard ratio (HR) = 2.85; 95%CI: 2.21, 3.66; P < 0.001] in centers performing 30 SLKT over the study period. This disadvantage was modestly attenuated as center SLKT volume increased, with a 3% reduction (HR = 0.97; 95%CI: 0.95, 0.99; P = 0.010) for every 10 SLKs performed.

CONCLUSION

In conclusion, LTA is associated with increased mortality among patients listed for SLKT. This difference is modestly attenuated at more experienced centers and may explain inconsistencies between smaller-center and larger registry-wide studies comparing SLKT and LTA outcomes.

Individual Surgeon Experience Yields Bimodal Effects on Patient Outcomes After Deceased-Donor Liver Transplant: Results of a Quantile Regression for Survival Data

OBJECTIVES

Data on the relevance of surgeon experience in liver transplant procedures are scarce. In this study, we evaluated the effects of individual surgeon experience on survival outcomes after deceased-donor liver transplant.

MATERIALS AND METHODS

In this retrospective analysis of 1193 liver transplant procedures, quantile regression for survival data was performed to assess the effects of surgeon experience. Conditional quantiles of mortality and graft loss were set as primary and secondary outcome measures, respectively, which were categorized as early, midterm, and late.

RESULTS

Greater experience of a surgeon performing hepatectomy increased the risk of early mortality (P = .005) and graft loss (P = .025) when the recipient Model for End-Stage Liver Disease was ≤ 25 and the donor Model for End-Stage Liver Disease was ≤ 1600. In conventional transplant procedures, greater experience of surgeon performing hepatectomy additionally increased the risk of midterm mortality (P = .027) and graft loss (P = .046). Conversely, a graft implant procedure performed by a more experienced surgeon was associated with better early, midterm, and late outcomes after conventional transplants (all P < .037) and reduced the risk of early graft loss when the donor Model for End-Stage Liver Disease score was > 1600 (P = .027).

CONCLUSIONS

Unexpectedly, individual surgeon experience yields bimodal effects on posttransplant outcomes, dependent on the stage of operation, operative technique, severity of recipient status, and transplant risk profile.

High Center Volume Does Not Mitigate Risk Associated with Using High Donor Risk Organs in Liver Transplantation

BACKGROUND

High-risk donor allografts increase access to liver transplant, but potentially reduce patient and graft survival.

AIMS

It is unclear whether the risk associated with using marginal donor livers is mitigated by increasing center experience.

METHODS

The United Network for Organ Sharing registry was queried for adult first-time liver transplant recipients between 2/2002 and 12/2015. High donor risk was defined as donor risk index >1.9, and 1-year patient and graft survival were compared according to donor risk index in small and large centers. Multivariable Cox regression estimated the hazard ratio (HR) associated with using high-risk donor organs, according to a continuous measure of annual center volume.

RESULTS

The analysis included 51,770 patients. In 67 small and 67 large centers, high donor risk index predicted increased mortality (p = 0.001). In multivariable analysis, high-donor risk index allografts predicted greater mortality hazard at centers performing 20 liver transplants per year (HR 1.35; 95% CI 1.22, 1.49; p < 0.001) and, similarly, at centers performing 70 per year (HR 1.35; 95% CI 1.26, 1.43; p < 0.001). The interaction between high donor risk index and center volume was not statistically significant (p = 0.747), confirming that the risk associated with using marginal donor livers was comparable between smaller and larger centers. Results were consistent when examining graft loss.

CONCLUSION

At both small and large centers, high-risk donor allografts were associated with reduced patient and graft survival after liver transplant. Specific strategies to mitigate the risk of liver transplant involving high-risk donors are needed, in addition to accumulation of center expertise.

The donor risk index: A decade of experience

In 2006, derivation of the donor risk index (DRI) highlighted the importance of donor factors for successful liver transplantation. Over the last decade, the DRI has served as a useful metric of donor quality and has enhanced our understanding of donor factors and their impact upon recipients with hepatitis C virus, those with low Model for End-Stage Liver Disease (MELD) score, and individuals undergoing retransplantation. DRI has provided the transplant community with a common language for describing donor organ characteristics and has served as the foundation for several tools for organ risk assessment. It is a useful tool in assessing the interactions of donor factors with recipient factors and their impact on posttransplant outcomes. However, limitations of statistical modeling, choice of donor factors, exclusion of unaccounted donor and geographic factors, and the changing face of the liver transplant recipient have tempered its widespread use. In addition, the DRI was derived from data before the MELD era but is currently being applied to expand the donor pool while concurrently meeting the demands of a dynamic allocation system. A decade after its introduction, DRI remains relevant but may benefit from being updated to provide guidance in the use of extended criteria donors by accounting for the impact of geography and unmeasured donor characteristics. DRI could be better adapted for recipients with nonalcoholic fatty liver disease by examining and including recipient factors unique to this population. Liver Transplantation 23 1216-1225 2017 AASLD.

Surgical issues in retrieval and implantation

With increasing demand for organ transplantation and patients deteriorating or dying on the waiting list, organs are now being increasingly used from donors previously considered too marginal. This requires improvements to donor management during the retrieval process, and of the organ during transport and subsequent implantation, in order to maintain outcomes.

The center volume-outcome effect in pancreas transplantation: a national analysis

BACKGROUND

Although increased hospital volume has been correlated with improved outcomes in certain surgical procedures, the effect of center volume on pancreas transplantation (PT) is less understood. Our study aims to establish whether a volume-outcome effect exists for PT.

METHODS

Through an established linkage between the University HealthSystem Consortium and the Scientific Registry of Transplant Recipients (SRTR) databases, we performed a retrospective cohort analysis of adult PT recipients between 2009 and 2012. Surgical volume was divided equally into low volume (LV), middle volume (MV), and high volume (HV) tertiles for each year that was studied. Hospital outcomes were measured through University HealthSystem Consortium, and long-term outcomes were measured through Scientific Registry of Transplant Recipients. Statistical analysis was performed using regression analyses and the Kaplan-Meier method. Median follow-up period was 2 y.

RESULTS

Among the 2309 PT recipients included, 815 (35.3%) were performed at LV centers, 755 (32.7%) at MV centers, and 739 (32.0%) at HV centers. Compared with MV and LV centers, organs transplanted at HV centers were more frequently donation after cardiac death (5.1% versus 2.4% versus 3.3%, P = 0.01) and from older donors (2.8% [>50 y] versus 0.8% versus 0.1%, P < 0.001). In addition, HV recipients were older (31.5% [>50 y] versus 20.9% versus 19.7%, P < 0.001) and had worse functional status (39.5% dependent versus 9.7% versus 9.9%, P < 0.001). Patient and graft survival were similar across hospital volume tertiles. Center volume was not predictive of readmission rates, total length of stay, intensive care unit length of stay, or total direct cost on multivariate analysis (all P > 0.05).

CONCLUSIONS

Short- and long-term outcomes after PT are not affected by hospital volume. Although LV centers confine their cases to low-risk patients, HV centers transplant a higher percentage of high-risk donor and recipient combinations with equivalent outcomes.

Economics and Outcome After Hematopoietic Stem Cell Transplantation: A Retrospective Cohort Study

Hematopoietic stem cell transplantation (HSCT) is a lifesaving expensive medical procedure. Hence, more transplants are performed in more affluent countries. The impact of economic factors on patient outcome is less defined. We analyzed retrospectively a defined cohort of 102,549 patients treated with an allogeneic (N = 37,542; 37%) or autologous (N = 65,007; 63%) HSCT. They were transplanted by one of 404 HSCT centers in 25 European countries between 1999 and 2006. We searched for associations between center-specific microeconomic or country-specific macroeconomic factors and outcome. Center patient-volume and center program-duration were significantly and systematically associated with improved survival after allogeneic HSCT (HR 0·87; 0·84-0·91 per 10 patients; p < 0·0001; HR 0·90;0·85-0·90 per 10 years; p < 0·001) and autologous HSCT (HR 0·91;0·87-0·96 per 10 patients; p < 0·001; HR 0·93;0·87-0·99 per 10 years; p = 0·02). The product of Health Care Expenditures by Gross National Income/capita was significantly associated in multivariate analysis with all endpoints (R(2) = 18%; for relapse free survival) after allogeneic HSCT. Data indicate that country- and center-specific economic factors are associated with distinct, significant, systematic, and clinically relevant effects on survival after HSCT. They impact on center expertise in long-term disease and complication management. It is likely that these findings apply to other forms of complex treatments.

Impact of recipient morbid obesity on outcomes after liver transplantation

The aim of this study was to analyze the impact of morbid obesity in recipients on peritransplant resource utilization and survival outcomes. Using a linkage between the University HealthSystem Consortium and Scientific Registry of Transplant Recipients databases, we identified 12 445 patients who underwent liver transplantation (LT) between 2007 and 2011 and divided them into two cohorts based on recipient body mass index (BMI; <40 vs. ≥40 kg/m²). Recipients with BMI ≥40 comprised 3.3% (n = 416) of all LTs in the studied population. There were no significant differences in donor characteristics between two groups. Recipients with BMI ≥40 were significant for being female, diabetic, and with NASH cirrhosis. Patients with a BMI ≥40 had a higher median MELD score, limited physical capacity, and were more likely to be hospitalized at LT. BMI ≥40 recipients had higher post-LT length of stay and were less often discharged to home. With a median follow-up of 2 years, patient and graft survival were equivalent between the two groups. In conclusion, morbidly obese LT recipients appear sicker at time of LT with an increase in resource utilization but have similar short-term outcomes.

Accepting multiple simultaneous liver offers does not negatively impact transplant outcomes

Impact of performing multiple liver transplants (LT) in a short period of time is unknown. Consecutively performed LT potentially increase complication rates through team fatigue and overutilization of resources and increase ischemia time. We analyzed the impact of undertaking consecutive LT (Consecutive liver transplant, CLT; LT preceded by another transplant performed not more than 12 h before, both transplants grouped together) on outcomes. Of 1702 LT performed, 314 (18.4%) were CLT. Outcome data was compared with solitary LT (SLT; not more than one LT in 12-h period). Recipient, donor, and graft characteristics were evenly matched between SLT and CLT; second LT of CLT group utilized younger donors grafts with longer cold ischemic times (P = 0.015). Implantation and operative time were significantly lower in CLT recipients on intergroup analysis (P = 0.0001 and 0.002, respectively). Early hepatic artery thrombosis (E-HAT) was higher in CLT versus SLT (P = 0.038), despite absolute number of E-HAT being low in all groups. Intragroup analysis demonstrated a trend toward more frequent E-HAT in first LT, compared to subsequent transplants; however, difference did not reach statistical significance (P = 0.135). In era of organ scarcity, CLT performed at high-volume center is safe and allows pragmatic utilization of organs, potentially reducing number of discarded grafts and reducing waiting list mortality.

Patterns and Outcomes Associated with Patient Migration for Liver Transplantation in the United States

Background

Traveling to seek specialized care such as liver transplantation (LT) is a reality in the United States. Patient migration has been attributed to organ availability. The aims of this study were to delineate patterns of patient migration and outcomes after LT.

Study Design

All deceased donor LT between 2008–2013 were extracted from UNOS data. Migrated patients were defined as those patients who underwent LT at a center in a different UNOS region from the region in which they resided and traveled a distance > 100 miles.

Results

Migrated patients comprised 8.2% of 28,700 LT performed. Efflux and influx of patients were observed in all 11 UNOS regions. Regions 1, 5, 6, and 9 had a net efflux, while regions 2, 3, 4, 7, 10, and 11 had a net influx of patients. After multivariate adjustment for donor and recipient factors, graft (p = 0.68) and patient survival (p = 0.52) were similar between migrated and non-migrated patients.

Conclusion

A significant number of patients migrated in patterns that could not be explained alone by regional variations in MELD score and wait time. Migration may be a complex interplay of factors including referral patterns, specialized services at centers of excellence and patient preference.

Effect of pretransplant diabetes on short-term outcomes after liver transplantation: a national cohort study

BACKGROUND & AIMS

We sought to analyse the effect of pretransplant diabetes on post-operative outcomes and resource utilization following liver transplantation.

METHODS

A retrospective cohort study was designed using a linkage between the University HealthSystem Consortium and Scientific Registry of Transplant Recipients databases. We identified 12 442 patients who underwent liver transplantation at 63 centres from 2007-2011 and separated cohorts of patients with diabetes (n = 2971; 24%) and without (n = 9471; 76%) at the time of transplant. We analysed transplant related outcomes and short-term survival.

RESULTS

Diabetic recipients were more likely to be male (70% vs 67%), non-white (32% vs 26%), older (age ≥60; 41% vs 28%), and have a higher BMI (29 vs 27; P < 0.001). More diabetic patients were on haemodialysis (10% vs 7%), had cirrhosis caused by NASH (24% vs 9%; P < 0.001), and received liver allografts from older donors (≥ 60 years; 19% vs 15%) with a higher donor risk index (>1.49; 46% vs 42%; P < 0.001). Post-transplant, diabetic recipients had longer hospital length of stay (10 vs 9 days), higher peri-transplant mortality (5% vs 4%) and 30-day readmission rates (41% vs 37%), were less often discharged to home (83% vs 87%; P < 0.05), and had inferior graft and patient survival. Liver transplant was more expensive for type 1 vs type 2 diabetics ($105 078 vs $100 624, P < 0.001). Poorly controlled diabetic recipients were less likely discharged home following transplant (75% vs 82%, P < 0.01).

CONCLUSIONS

This national study indicates that pretransplant diabetes is associated with inferior post-operative outcomes and increased resource utilization after liver transplantation.