Simultaneous Liver–Kidney Transplantation: Evaluation to Decision Making

Authors


* Corresponding author: Connie L. Davis, cdavis@u.washington.edu

Abstract

Questions about appropriate allocation of simultaneous liver and kidney transplants (SLK) are being asked because kidney dysfunction in the context of liver failure enhances access to deceased donor organs. There is specific concern that some patients who undergo combined liver and kidney transplantation may have reversible renal failure. There is also concern that liver transplants are placed prematurely in those with end-stage renal disease. Thus to assure allocation of transplants only to those truly in need, the transplant community met in March 2006 to review post-MELD (model for end-stage liver disease) data on the impact of renal function on liver waitlist and transplant outcomes and the results of SLK.

Introduction

The introduction of MELD (model for end-stage liver disease) prioritization for liver transplant, which is greatly influenced by renal dysfunction, has coincided with an increase in simultaneous liver–kidney transplantation (SLK). SLK has increased from an average of 110 per year pre-MELD up to 368 in 2006 post-MELD (1). A prime motivation to perform SLK in end-stage liver disease (ESLD) candidates is the potent negative impact of renal insufficiency (acute or chronic) on liver transplant outcomes (2,3). Several large studies over the last 11 years have shown that pre-transplant renal failure is associated with increased post-transplant end-stage renal disease (ESRD), higher mortality and diminished quality of life (2–5). Controversy surrounding SLK centers on the questions of how to determine recovery of acute kidney injury (AKI) in the setting of ESLD and the ‘net benefit’ of kidney transplant in liver candidates with kidney failure. Furthermore, the higher MELD scores in transplant candidates receiving liver transplant alone (LTA) compared to SLK also suggest some SLK (with ESRD) have less severe liver disease than LTA and may be receiving a liver transplant prematurely.

Disparity in the recovery of AKI in waitlisted candidates and the level of kidney dysfunction at transplant for SLK compared to kidney transplant alone (KTA) recipients is demonstrated by the following data. In 2005, 59.0% of those receiving deceased donor SLK were on dialysis at transplant compared to 85.6% of those receiving a KTA. The average pre- and post-MELD era MDRD (modification of diet in renal disease) calculated glomerular filtration rate (eGFR) of recipients not on dialysis at kidney transplantation has been consistently higher for SLK compared to KTA recipients (Tables 1 and 2). Since MELD allocation began, 15% (40/265) of those on dialysis at listing for LTA have discontinued dialysis by the time of transplant where as 6.5% (n = 24/371) of those listed for SLK and 4.3% (771/17 862) of those listed for KTA have discontinued dialysis prior to transplant (Table 3).

Table 1.  Mean MDRD GFR at time of listing for transplant candidates pre-MELD (1/1999–2/2002) and post-MELD (3/2002–12/2005)
Type of listingLTA no dialysisSLK no dialysisKTA no dialysis
Pre-MELD89.428.413.1
Post-MELD84.725.814.2
Table 2.  MDRD GFR at time of transplant for candidates pre-MELD (1999–2002) and post-MELD (2/2002–12/2005)
Type of TXLTA no dialysisSLK no dialysisKTA no dialysis
Pre-MELD81.427.410.7
Post-MELD77.625.511.6
Table 3.  Dialysis status at listing and at transplant among transplant recipients: Dialysis status at listing versus dialysis status at transplant (2/27/02–6/30/05, patients were listed and transplanted during this time period)
 No dialysis at transplantDialysis at transplant
LTA candidates
 No dialysis at listing10 972301
 Dialysis at listing40225
SLK candidates
 No dialysis at listing29689
 Dialysis at listing24347

To review the impact of renal disease on liver transplant outcome, the benefit of SLK and to better standardize the evaluation and selection of SLK candidates, a consensus conference of hepatologists, transplant surgeons, nephrologists and coordinators convened in March 2006. The agenda included a review of the Scientific Registry of Transplant Recipients (SRTR) liver transplant data (with a focus on the post-MELD data) and individual center reports on factors predicting post-transplant renal failure such as the pre-transplant duration of dialysis and renal histology. After the data presentation, participants met in work groups to discuss the following topics: the evaluation of kidney disease in ESLD, selection criteria for SLK, impact of hepatorenal syndrome (HRS) treatment on kidney function, treatment of acute renal failure in liver failure and new data needed to better identify risk factors for post-transplant renal failure. Each group developed a consensus approach that was presented to all conferees for discussion. This report is the summary of consensus agreements reached during these discussions. The writing of this consensus statement was the responsibility of the work group leaders and presenters of the individual center data.

Background Data

Scientific Registry of Transplant Recipients (SRTR)/Organ Procurement and Transplant Network (OPTN)

SRTR/OPTN data for adult, nonstatus 1 candidates waitlisted for liver transplant from the start of the MELD allocation system (2/27/02) through 12/30/2005 were reviewed. Only the first listing of a candidate during the study period was included, irrespective of previous transplantation. Kidney-related data included, serum creatinine at waitlisting, transplant and end of follow-up along with dialysis status at waitlisting, MELD score updates and transplant. The actual date of pre-transplant dialysis initiation, however, was unavailable. Patients were considered to be on dialysis if dialysis was performed twice in the prior week. The time of waitlisting for SLK candidates was considered to be the most recent of either liver or kidney listing dates. The analysis included the following candidates: 27  343 LTA not on dialysis at listing, 577 LTA on dialysis at listing, 605 SLK not on dialysis at listing and 579 SLK on dialysis at listing. The median MELD scores at listing and at transplant were 14 and 18, respectively, for LTA not on dialysis, 38 and 39 for LTA on dialysis, 25 and 26 for SLK not on dialysis and 31 and 31 for SLK on dialysis. These data suggest that MELD scores in some patients with ESRD listed for liver transplant may be driven by their kidney failure independent of liver disease and thus compared to LTA candidates on dialysis have a less urgent need for liver transplant. Liver transplant for metabolic or genetic diseases resulting in kidney failure (hyperoxaluria, polycystic disease) could also contribute to the difference in MELD scores. This issue is further discussed below.

Dialysis status often changed between listing and transplant. Some individuals were listed while on dialysis but were able to discontinue dialysis by transplant (Table 3). In contrast, others initiated dialysis while waitlisted (Table 3). Additionally, listing for SLK did not always result in SLK transplant; 53 of 756 (7.0%) listed for SLK received LTA instead, perhaps indicating improved kidney function. Although the real reasons for performing LTA instead of SLK are not known, it could also denote acceptance of a liver only offer (poor donor kidney quality) or perhaps concern over kidney transplant viability in an unstable liver candidate. Overall, these data show that liver transplant candidates experience both reversible and progressive renal dysfunction.

Unadjusted waitlist mortality for each of the listing groups was determined by calculating the time from waitlisting to death, with censoring at time of transplant or end of study (Figure 1). Liver candidates with renal dysfunction, indicated by dialysis status or concomitant kidney listing, had increased mortality. Although LTA candidates on dialysis at listing had the greatest short-term mortality, their subsequent survival curve roughly paralleled that of LTA candidates not on dialysis at listing. Although SLK candidates had better short-term survival than LTA candidates on dialysis (30 day survival 74.2% SLK on dialysis, 63.1% LTA on dialysis), survival was worse over the entire follow-up period (one-year survival 31.1% SLK on dialysis, 50.6% LTA on dialysis). LTA candidates on dialysis at listing had higher mean MELD scores than did SLK candidates on dialysis, reflective of more severe liver disease. This is so because the serum creatinine used in both groups for MELD calculation was 4.0 mg/dl; the MELD difference between the groups was determined by the INR and serum bilirubin. Listing for LTA in spite of requiring dialysis presumably reflects reversible renal dysfunction caused by severe liver disease. In contrast, SLK candidates are likely to be a more heterogeneous group with regard to both liver disease severity (e.g. some without cirrhosis, hyperoxaluria, polycystic disease) and chronicity of renal dysfunction. Thus, increased short-term mortality in LTA candidates may reflect differences in the severity of liver disease, while the greater long-term mortality in SLK candidates may be more a consequence of sustained renal failure.

Figure 1.

Unadjusted Kaplan–Meier waitlist survival for all liver transplant candidates by kidney listing and dialysis status for candidates waitlisted from 2/27/02 through 6/30/05; survival determined as category at listing without crossover, censored at transplant. The number of patients awaiting transplant at each time point is shown in the table below the figure. HD = hemodialysis; LI = liver transplant; KI = kidney transplant; LIKI = liver kidney transplant; no = no dialysis.

The SRTR reviewed preliminary Cox regression models (not shown), estimating the relative risk of death on the waitlist based on listing and dialysis status and adjusted for patient characteristics. In a time-dependent model that permits crossover into different waitlist groups over time, LTA candidates on dialysis had the greatest mortality, followed by SLK candidates on dialysis and SLK candidates not on dialysis. To address the concern that the mortality risk for a subset of SLK candidates (perhaps those with ESRD) is overestimated by the creatinine component of MELD, the time-dependent mortality model was adjusted for MELD. This analysis verified that the majority of the mortality difference was accounted for by liver disease severity; a one-point increase in MELD was associated with a 17% increase in mortality risk. Further development of these models with more complete and new data to improve adjustment for selection biases is needed to better clarify true differences in risk among these populations (see Data Needs).

Lesser degrees of renal dysfunction than the need for dialysis correlated with unadjusted LTA waitlist mortality (Figure 2). This was also true for post-transplant LTA survival as previously described (4). This association was not true for SLK candidates or recipients (Figures 3 and 4). Overall post-transplant mortality of LTA and SLK not on dialysis was comparable. Post-transplant mortality for SLK on dialysis was lower than that for LTA on dialysis, with a two-year post-transplant survival of 75.9% for SLK and 70.8% for LTA. The explanation for this is unknown; however, modeling of adjusted waitlist and post-transplant mortality for LTA and SLK recipients remains confounded by important selection biases and insufficient data to adequately address these biases (see Data Needs). For these reasons, detailed modeling is beyond the scope of this report.

Figure 2.

Unadjusted waitlist survival for LTA candidates by serum creatinine at listing for those waitlisted from 2/27/02 through 6/30/05. Kaplan–Meier curves are for waitlist survival by level of serum creatinine (mg/dL) < 1.0, 1.0–1.5, > 1.5–2.0, > 2.0, hemodialysis (HD).

Figure 3.

Unadjusted waitlist survival for SLK candidates by serum creatinine at listing for those waitlisted from 2/27/02 through 6/30/05. Kaplan–Meier curves are for waitlist survival by level of serum creatinine < 1.0, 1.0–1.5, > 1.5–2.0, > 2.0, hemodialysis (HD). The data shown for the group with a creatinine < 1.0 mg/dl without dialysis represents only six patients.

Figure 4.

Unadjusted post-transplant survival for SLK recipients by the serum creatinine at transplant for those transplanted from 2/27/02 though 6/30/05. Kaplan–Meier curves are for post-transplant survival by serum creatinine (mg/dl) < 1.0, 1.0–1.5, > 1.5–2.0, > 2.0, HD. Post-transplant mortality risk was calculated as the time from transplant to time of death, with censoring at end of follow-up or end of study (12/05).

One measure of the ability to predict short-term renal outcome after transplant is the need for a kidney transplant after LTA or SLK. Of LTA and SLK recipients, only a small number were listed for kidney transplant within 1 year of OLT (Table 4). Of the 38 patients (LTA and SLK) listed for kidney transplant within 1 year of OLT, only 12 (31.6%) were on dialysis at transplant (Table 5). The mean eGFR at OLT of the remaining 26 patients was 39.22 cc/min. Of the 53 SLK candidates who instead received LTA, 52 were alive and a few received a kidney transplant within 1 year of OLT (Table 5). The post-transplant dialysis status for the 51 remaining recipients is unavailable from the SRTR. Overall these data suggest that kidney transplant is not commonly needed within the first year after OLT and dialysis requirement alone prior to transplant does not reliably predict the need for future kidney transplant. This analysis does not account for pre-transplant characteristics such as hypertension and diabetes which may contribute to later ESRD nor the development of ESRD without listing for kidney transplant (5).

Table 4.  Number listed for kidney transplant within 1 year for transplanted recipients by dialysis status
Transplant groupNN (%) with KI listing within 1 yearN (%) with KI transplant with 1 year
LTA no HD692025 (0.36%)  2 (0.03%)
LTA with HD 3316 (1.81%) 2 (0.60%)
SLK no HD1601 (0.63%)0 (0%)  
SLK with HD2376 (2.53%)0 (0%)  
Table 5.  Number listed for kidney transplant within one year for transplanted recipients by listing type and transplant type
Transplant groupNN (%) with KI listing within 1 yearN (%) with KI transplant with 1 year
  1. KI = kidney transplant.

Listed LTA, received LTA719830 (0.42%)  2 (0.03%)
Listed SLK, received LTA531 (1.89%) 2 (3.77%)
Listed SLK, received SLK3877 (1.81%)0 (0%)  

In summary, renal dysfunction, in a graded fashion, negatively impacts pre- and post-liver transplant outcome. Pre-transplant renal failure may be reversible or may progress. Liver disease severity appears more pronounced in waitlisted LTA candidates on dialysis than for waitlisted SLK candidates. For candidates on dialysis at transplant, SLK survival is superior to LTA. However, this is not the case for those with lesser degrees of renal impairment. Within a year of transplant, a small percentage of OLT will need renal transplantation.

Single Center Data

Duration of renal insufficiency and dialysis for AKI as predictors of renal outcome

The duration of an elevated serum creatinine (creatinine > 1.5 mg/dl) before LTA predicts the serum creatinine 6–12 months after LTA (6). Although the duration of renal dysfunction may signify permanent damage it is not currently a variable known to help select candidates for SLK (6). To the contrary, dialysis duration has been used by many centers to select candidates for SLK. However, only one study reviews the impact of dialysis duration on liver transplant outcome. Ruiz et al. compared the results of patients with hepatorenal syndrome (HRS) receiving SLK (n = 22 on HD for ≥ 4 weeks at transplant) to those receiving LTA (n = 80, on HD for < 4 weeks at transplant) (Table 6) (7). One-year survival for patients with HRS undergoing SLK or LTA was 72% and 66%, respectively (p = 0.876). SLK recipients on HD for ≥ 8 weeks pre-transplant demonstrated improved survival as well as resource utilization compared to LTA on HD prior to transplant. Equal survival was noted for LTA on HD for < 4 weeks and SLK on HD for four-eight weeks. More patients who received LTA (89%) compared to SLK (55%) required post-transplant dialysis; post-transplant dialysis time for LTA exceeded that for SLK by 1 week. However, the majority of LTA patients were dialysis free one month after transplant, only three of 80 patients remained on long-term dialysis. With a median follow-up period of 260 days, the median creatinine in LTA had dropped to 1.55 mg/dl (mean ± SD = 1.87 ± 1.22). These results document, as previously suggested, that renal function may rapidly return after LTA in dialysis dependent patients with HRS (3).

Table 6.  Outcome of HRS by Pre-transplant dialysis duration (7)
GroupLTASLK
  1. 1Range for the duration of dialysis pre SLK was between 4–234 days, tx = transplant.

  2. 2Range for the duration of posttransplant dialysis in the SLK recipient was 1–89 days.

  3. Four LTA recipients required long-term dialysis.

  4. 3The MELD scores were calculated from immediate preoperative values and presented as the median score.

Number80148
HD duration pre-tx1< 30 days< 8 weeks> 8 weeks
MELD3373534
Percentage needing post-tx89%79%13%
 dialysis 
Median duration of post-910.50
 transplant dialysis (days)2 
Median length of stay (days)254725
One year patient survival66%64%88%

Thus at a minimum, models being developed to help determine the need for kidney transplant should consider the degree and duration of kidney failure prior to liver transplant. In addition, another marker of severe liver disease (e.g. serum bilirubin) should be included to improve the model accuracy (6). However, it is likely that more specific tests such as determinants of renal blood flow and the renal biopsy will be needed to improve predictive values.

Renal biopsy

Renal biopsy has rarely been reported as a component of the pre-transplant liver evaluation, even when considering a concurrent kidney transplant. Recently, however, Pichler et al. reported kidney biopsies performed in 26 liver transplant candidates with renal insufficiency of unknown etiology or HRS that persisted > 4 weeks (8). The transjugular approach was used in 21 of 26 candidates. Pathologic findings included membranoproliferative glomerulonephritis (MPGN) (n = 6), IgA nephropathy (IgAN) (n = 5), AKI (n = 4), normal histology (n = 4), focal global glomerulosclerosis (n = 4), diabetic nephropathy (n = 3) and thrombotic microangiopathy. Thus renal histology in patients with liver failure is varied and may potentially alter therapeutic strategies including the need for SLK.

Two prior series of renal biopsies performed during OLT also reported diverse histology as well as limited urinary or serum findings that would signify histologic abnormalities (9,10). These recent results parallel those of earlier studies in patients with ESLD (11,12). Thus irrespective of urine, blood or functional testing results, glomerular and tubular abnormalities are relatively common in the setting of severe liver disease.

However, more important than the glomerular diagnosis when trying to predict progression to ESRD is the amount of fixed renal scarring indicative of permanent renal loss as denoted by the percent of interstitial fibrosis, arterial hyalinosis and glomerular sclerosis (13). These criteria, however, have not been formally evaluated in patients with cirrhosis. Even so, conferees indicated that their institutions used these parameters to determine SLK candidacy (14). More than 30–50% glomerulosclerosis, arteriolar hyalinosis, tubular atrophy and interstitial fibrosis are the usual biopsy criteria used to select SLK over LTA. In the study by Pichler et al., SLK was recommended for 10 of 26 their patients with > 40% global glomerulosclerosis, > 30% of the interstitium composed of interstitial fibrosis or for severe glomerular ischemia/injury (8). To date, nine of the 26 patients have been transplanted, five with LTA and four with SLK. Further multicenter long-term study is needed to help prioritize renal biopsy in the pre-OLT evaluation.

Coagulopathy represents a major deterrent to the performance of kidney biopsies in patients with cirrhosis. Biopsy may be performed with a minimum of risk by the transjugular approach in such patients (11,12). Conferees revealed that many centers are now performing kidney biopsy in select liver transplant candidates. They also agreed that although published reports classify renal biopsy as relatively safe, complication rates need to be more globally reviewed and reported.

Kidney transplant outcome: SLK versus KTA

One concern regarding the ‘net benefit’ of SLK transplantation has been the lower survival of renal allografts in SLK compared to KTA recipients (7,15). UCLA recently reported increased early graft loss (within 6 months) among 99 SLK predominately due to sepsis or multiorgan failure (7). These findings echoed a previous report comparing 800 SLK to 800-paired kidneys given to KTA and kidney–pancreas recipients between 1987–2001 (15). Graft and patient survival were inferior in SLK due to increased mortality secondary to infection. Complicating this matter is a more recent report describing decreased survival of kidney after liver transplant compared to SLK (16). Additionally, another report details the possible benefit of delaying kidney transplant until after the time renal recovery is usually manifest, 30–60 days after LTA (17). Obviously, more in-depth discussion of this issue in the face of more precise data are necessary.

Evaluation

Assessment of a liver transplant candidate with established ESRD should proceed according to institutional protocols. For candidates without ESRD, renal function should be assessed at every pre-transplant visit. Although the serum creatinine is notoriously inaccurate as a measure of renal function especially in a patient with ESLD, it is easily available and can be helpful. ‘Normal creatinine’ levels in ESLD should be the lower limit of normal, usually 0.7–0.8 mg/dL. If the creatinine is near, at or above the upper limit of normal, a more thorough renal evaluation should be performed (Figure 5) (18,19). The evaluation algorithm should aim to differentiate acute, reversible renal insufficiency from fixed renal disorders and/or fixed anatomic abnormalities. As discussed previously, renal histological abnormalities may be present without clinical signs or symptoms. A nephrologist should preferably evaluate all liver transplant candidates with a GFR < 50 cc/min. Finally, to limit renal injury, conferees felt strongly that HRS should be treated aggressively with the newest available modalities at all liver transplant programs (20–22).

Figure 5.

Algorithm for SLK candidate evaluation.

Selection

In the setting of chronic kidney disease, a measured creatinine clearance (or preferentially an iothalamate clearance) of ≤ 30 cc/min was considered the appropriate threshold for SLK (23). In the setting of acute renal failure secondary to HRS and/or AKI, conferees agreed renal dysfunction requiring dialysis may reflect recurrent or persistent injury and thereby signal decreased capacity for renal recovery (6,7,23,24). As such, selection for SLK based upon dialysis duration was considered valid. Initially conferees differed widely but ultimately agreed to six weeks as the dialysis duration threshold to merit SLK. In the setting of acute but nondialysis requiring kidney failure, SLK was not felt warranted as LTA recipients with an eGFR < 30 cc/min had a 1-year post-transplant survival of 81.5% and only 25/1648 (1.5%) of these recipients were listed for kidney transplant within a year of their OLT. In candidates with prolonged acute kidney failure or kidney failure of unknown cause, a decision for SLK based upon a kidney biopsy showing fixed renal damage as described above was felt to be valid.

Data Needs

Available SRTR data are limited in the ability to address the central questions surrounding SLK transplantation. Current reporting mechanisms fail to capture any distinction between fixed and reversible renal insufficiency. In addition, dialysis duration cannot be ascertained for the many recipients listed while on dialysis. Without this data, comparisons of survival outcomes between SLK and LTA recipients are more likely to reflect selection bias based on dialysis duration and cause of renal failure rather than the impact of the kidney transplant.

In order to provide the data to answer current and future questions regarding appropriate selection of SLK candidates, additional SRTR data fields are needed. However, given the move by UNOS to decrease data fields, conferees concluded that the most important new data field to add was the dialysis-start-date for registrants on dialysis at the time of initial listing. For more complete and prospective data capture, a multicenter research study was proposed by conferees for liver transplant candidates and recipients.

Summary

The consensus conference established baseline evaluation and selection criteria and new data to be collected on liver transplant candidates with renal insufficiency. The next step is to use these criteria and start collecting data that will help to improve future allocation of kidneys in the setting of liver failure.

Acknowledgments

The conference was supported by the UNOS Foundation, American Society of Transplantation, American Society of Transplant Surgeons, American Society of Nephrology, International Liver Transplantation Society, American Association for the Study of Liver Diseases and North American Transplant Coordinators Organization. The Scientific Registry of Transplant Recipients is funded by contract number 234-2005-37009C from the Health Resources and Services Administration (HRSA), U.S. Department of Health and Human Services. The views expressed herein are those of the authors and not necessarily those of the U.S. Government. This study was approved by the Health Resources and Services Administration, which has determined that it satisfies the criteria for the IRB exemption described in the “Public Benefit and Service Program” provisions of 45 CFR 46.101(b)(5) and HRSA Circular 03.

Appendix

Appendix: Conference Participants

Karen M. Abu Elmagd, MD, University of Pittsburgh Medical Center.

Aijaz Ahmed, MD, Stanford University Medical Center.

Shubhada Ahya, MD, Northwestern University.

Mohamed Akoah, MD, VA Pittsburgh Healthcare System.

Angel E. Alsena, MD, Lifelink.

Michael Angelis, MD, Translife, Florida Hospital.

Victor Araya, MD, Albert Einstein Medical Center.

Prabhakav Baliga, MD, Medical University of South Carolina.

Alex Befeler, MD, Saint Louis University.

Jacques Belghiti, MD, Hosp Beaujon University of Paris VII.

Frederick R. Bentley, MD, University of Louisville.

Scott Biggins, MD, University of California San Francisco.

Jamie Blazek Ochsner Transplant Center.

Jean Botha, MD, University of Nebraska Medical Center.

Adel Bozorgzadeh, MD, University of Rochester Medical Center.

William C. Chapman, MD, Washington University in St. Louis.

Connie Davis, MD, University of Washington.

Gary L. Davis, MD, Baylor University Medical Center.

Sonu Dhillon, MD, Loyola University Medical Center.

S. Forrest Dodson, MD, Rush University Medical Center.

John A. Donovan, MD, University of South Carolina.

Richard W. Dow, MD, Dartmouth-Hitchcock Medical Center.

Francois Durand, MD, Hospitale Beaujon, University of Paris VII.

James Eason, MD, Ochsner Foundation Hospital.

Erick B. Edwards, MD, United Network for Organ Sharing.

Sukru Emere, MD, Mount Sinai School of Medicine.

Michael Fallon, MD, University of Alabama at Birmingham.

Sandy Feng, MD, University of California San Francisco.

Richard Freeman, MD, New England Medical Center.

Jonathan Fryer, MD, Northwestern Memorial Hospital University.

Paul J. Gaglio, MD, Center for Liver Disease & Transplantation Columbia University.

Lorenzo Gallon, MD, Northwestern University.

Robert Gish, MD, California Pacific Med Center.

Douglas A. Heiney United Network for Organ Sharing.

Martin Hertl, MD, Massachusetts General Hospital.

Douglas M. Heuman, MD, Hunter Holmes McGuire VA Medical Center.

S. Paul Hmiel, MD, St. Louis Children Hospital.

Robert A. Hunter United Network for Organ Sharing.

William Hutson, MD, University of Utah – School of Medicine.

Patrick S. Kamath, MD, Mayo Clinic College of Medicine.

Nyingi Kemmer, MD, University of Cincinnati.

Ajai Khanna, MD, University of California San Diego Medical Center.

Heung Bae Kim, MD, Children's Hospital Boston.

Leona Kim-Schluger, MD, Westchester Medical Center – Transplant Center.

Goran Klintmalm, MD, Baylor University Medical Center.

Michael Krownka, MD, Mayo Foundation for Medical Education and Research.

John R. Lake, MD, University of Minnesota Med School

Leslie C. Lieblein United Network for Organ Sharing.

Victor Machicao, MD, North Florida/South Georgia Veterans Health System.

Warren R. Maley, MD, John Hopkins Hospital/Harvey 611.

James Markmann, MD, University of Pennsylvania Health Systems.

Christopher Marsch, MD, Scripps Health.

George V Mazariegos, MD, Children's Hospital of Pittsburgh.

Jerry McCauley, MD, University of Pittsburgh.

Brendan M. McGuire, MD, University of Alabama at Birmingham.

Larry Melton, MD, Baylor University Medical Center.

Charles M Miller, MD, Cleveland Clinic.

Dilip Moonka, MD, Henry Ford Hospital.

Adyr Moss, MD, Mayo Clinic.

Kevin Mullen, MD, MetroHealth Medical Center.

Victor J. Navarro, MD, Thomas Jefferson University.

Mark Orloff, MD, University of Rochester Medical Center.

Marian O'Rourke RN HCA Healthcare, New Orleans.

Jorge Ortiz, MD, Texas Transplant Institute.

Robert W. Osorio, MD, California Pacific Medical Center.

Samuel E. Perry United Network for Organ Sharing.

James B. Piper, MD, Inova Fairfax Hospital.

John Polio, MD, Hartford Hospital – Liver Transplant Program.

Elizabeth A Pomfret, MD, Lahey Clinic Medical Center.

Michael K. Porayko, MD, Vanderbilt University Medical Center.

Jeffrey Punch, MD, University of Michigan Medical Center.

Jorge Rakela, MD, Mayo Clinic.

Dinesh Ranjan, MD, University of Kentucky Medical Center.

Raj Reddy, MD, University of Pennsylvania Hospital.

Frederic Regenstein, MD, Tulane Abdominal Center – TW 35.

Burckhardt H. Ringe, MD, Drexel University College of Medicine.

Charles Rosen, MD, Mayo Clinic.

Barry Rosser, MD, FRCPC, Mayo Clinic Jacksonville.

Millie Samaniego, MD, University of Wisconsin – Madison.

Juan Sanabria, MD, University Hospitals of Cleveland – UHHS – Case WR University.

Howard N. Sankary, MD, University of Illinois at Chicago.

Arun Sanyal, MD, Virginia Commonwealth University.

Anthony Sebastian, MD, Nazih Zuhdi Transplantation Institute.

Nikunj Shah, MD, University of Illinois at Chicago.

Kirti Shatty, MD, Georgetown University Hospital.

Thomas Shaw-Stiffel, MD, University of Pittsburgh.

Ross Sheperd, MD, Washington Univ Sch of Med.

Inbo Shim, MD.

Arun Smanata, MD, University Hospital, New Jersey Medical School.

Robert E. Smith, MD, Geisinger Medical Center – MC 21–11.

K. V. Speeg, MD, University of Texas.

Randall Sung, MD, University of Michigan Health System.

Norman Sussman, MD, Baylor College of Medicine.

Jane Tan, MD, Stanford University Medical Center.

Guiliano Testa, MD, University of Chicago.

David H. Van Thiel, MD, Aurora Saint Luke Medical Center.

Santiago R. Vera, MD, University of Tennessee, Health Science Center.

John M. Vierling, MD, Baylor College of Medicine.

Kasturi Vinay Ranga, MD, Hartford Hospital.

Michael Voigt, MD, University of Iowa.

Jeffrey Weinstein, MD, Baylor University Medical Center Dallas.

Russell Wiesner, MD, Mayo Clinic.

Alan Wilkinson, MD, UCLA.

Florence Wong, MD, Toronto General Hospital.

Jens Goebel, MD, Cincinnati Children's Hospital Medical Center.

Ancillary