Erick B. Edwards

Hyponatremia and mortality among patients on the liver-transplant waiting list.

BACKGROUND Under the current liver-transplantation policy, donor organs are offered to patients with the highest risk of death. METHODS Using data derived from all adult candidates for primary liver transplantation who were registered with the Organ Procurement and Transplantation Network in 2005 and 2006, we developed and validated a multivariable survival model to predict mortality at 90 days after registration. The predictor variable was the Model for End-Stage Liver Disease (MELD) score with and without the addition of the serum sodium concentration. The MELD score (on a scale of 6 to 40, with higher values indicating more severe disease) is calculated on the basis of the serum bilirubin and creatinine concentrations and the international normalized ratio for the prothrombin time. RESULTS In 2005, there were 6769 registrants, including 1781 who underwent liver transplantation and 422 who died within 90 days after registration on the waiting list. Both the MELD score and the serum sodium concentration were significantly associated with mortality (hazard ratio for death, 1.21 per MELD point and 1.05 per 1-unit decrease in the serum sodium concentration for values between 125 and 140 mmol per liter; P<0.001 for both variables). Furthermore, a significant interaction was found between the MELD score and the serum sodium concentration, indicating that the effect of the serum sodium concentration was greater in patients with a low MELD score. When applied to the data from 2006, when 477 patients died within 3 months after registration on the waiting list, the combination of the MELD score and the serum sodium concentration was considerably higher than the MELD score alone in 32 patients who died (7%). Thus, assignment of priority according to the MELD score combined with the serum sodium concentration might have resulted in transplantation and prevented death. CONCLUSIONS This population-wide study shows that the MELD score and the serum sodium concentration are important predictors of survival among candidates for liver transplantation.

Liver and Intestine Transplantation in the United States 1998–2007

Liver transplantation numbers in the United States remained constant from 2004 to 2007, while the number of waiting list candidates has trended down. In 2007, the waiting list was at its smallest since 1999, with adults ≥50 years representing the majority of candidates. Noncholestatic cirrhosis was most commonly diagnosed. Most age groups had decreased waiting list death rates; however, children <1 year had the highest death rate. Use of liver allografts from donation after cardiac death (DCD) donors increased in 2007. Model for end‐stage liver disease (MELD)/pediatric model for end‐stage liver disease (PELD) scores have changed very little since 2002, with MELD/PELD <15 accounting for 75% of the waiting list. Over the same period, the number of transplants for MELD/PELD <15 decreased from 16.4% to 9.8%. Hepatocellular carcinoma exceptions increased slightly. The intestine transplantation waiting list decreased from 2006, with the majority of candidates being children <5 years old. Death rates improved, but remain unacceptably high. Policy changes have been implemented to improve allocation and recovery of intestine grafts to positively impact mortality. In addition to evaluating trends in liver and intestine transplantation, we review in depth, issues related to organ acceptance rates, DCD, living donor transplantation and MELD/PELD exceptions.

Effect of diagnosis on survival benefit of lung transplantation for end-stage lung disease

BACKGROUND Although certain forms of end-stage lung disease are debilitating, whether the associated mortality rate exceeds that of transplantation is unclear. We undertook analysis to clarify the survival benefit of lung transplantation for various types of end-stage lung disease. METHODS We analysed data for all patients listed for transplantation in the USA for emphysema, cystic fibrosis, or interstitial pulmonary fibrosis in the years 1992-94. The numbers of patients entered on the waiting list, post-transplantation, died waiting, and currently waiting were: emphysema group 1274, 843, 143, and 165; cystic fibrosis group 664, 318, 193, and 59; interstitial pulmonary fibrosis group 481, 230, 160, and 48. A time-dependent non-proportional hazard analysis was used to assess the risk of mortality after transplantation relative to that for patients on the waiting list. FINDINGS The clearest survival benefit from lung transplantation occurred in the cystic fibrosis group. The relative risks of transplantation compared with waiting were 0.87, 0.61, and 0.61 at 1 month, 6 months, and 1 year (p = 0.008), respectively. For interstitial pulmonary fibrosis, the corresponding relative risks were 2.09, 0.71, and 0.67 (p = 0.09). No survival benefit was apparent in the emphysema group. The risks of transplantation relative to waiting were 2.76, 1.12, and 1.10 at 1 month, 6 months, and 1 year, respectively, and the relative risk did not decrease to below 1.0 during 2 years of follow-up. INTERPRETATION These findings suggest that lung transplantation does not confer a survival benefit in patients with end-stage emphysema by 2 years of follow-up. Other benefits not accounted for in this analysis such as improved quality of life, however, may justify lung transplantation for these patients.

Results of the first year of the new liver allocation plan

Liver allocation policy in the U.S. was recently changed to a continuous disease severity scale with minimal weight given to time waiting in an effort to better prioritize deceased donor liver transplant candidates. We compared rates of waiting list registrations, removals, transplants, and deaths during the year prior to implementation of the new liver allocation policy (2/27/01–2/26/02, Era 1) with the first years experience (2/27/02–2/26/03, Era 2) under this new policy. Rates were adjusted for 1,000 patient years on the waiting list and compared using z‐tests. A 1‐sided test was used to compare death rates; 2‐sided tests were used to compare transplant rates. Overall and subgroup analyses were performed for demographic, geographic, and medical strata. In Era 2, we observed a 12% reduction in new liver transplant waiting list registrations, with the largest reductions seen in new registrants with low MELD/PELD scores. In Era 2, there was a 3.5% reduction in waiting list death rate (P = .076) and a 10.2% increase in cadaveric transplants (P < .001). The reduction in waiting list mortality and increase in transplantation rates were evenly distributed across all demographic and medical strata, with some variation across geographic variables. Early patient and graft survival after deceased donor liver transplantation remains unchanged. In conclusion, by eliminating the categorical waiting list prioritization system that emphasized time waiting, the new system has been associated with reduced registrations and improved transplantation rates without increased mortality rates for individual groups of waiting candidates or changes in early transplant survival rates. (Liver Transpl 2004;10:7–15.)

OPTN/SRTR 2015 Annual Data Report: Liver.

ABSTRACT  The current liver allocation system, introduced in 2002, decreased the importance of waiting time for allocation priorities; the number of active wait‐listed candidates and median waiting times were immediately reduced. However, the total number of adult wait‐listed candidates has increased since 2002, and median waiting time has increased since 2006. Pretransplant mortality rates have been stable, but the number of candidates withdrawn from the list as being too sick to undergo transplant nearly doubled between 2009 and 2011. Deceased donation rates have remained stable, with an increasing proportion of expanded criteria donors. Living donation has decreased over the past 10 years. Transplant outcomes remain robust, with continuously improving graft survival rates for deceased donor, living donor, and donation after circulatory death livers. Numbers of new and prevalent pediatric candidates on the waiting list have decreased. Pediatric pretransplant mortality has decreased, most dramatically for candidates aged less than 1 year. The transplant rate has increased since 2002, and is highest in candidates aged less than 1 year. Graft survival continues to improve for pediatric recipients of deceased donor and living donor livers. Incidence of acute rejections increases with time after transplant. Posttransplant lymphoproliferative disorder remains an important concern in pediatric recipients.

Report of a national conference on liver allocation in patients with hepatocellular carcinoma in the United States.

A national conference was held to better characterize the long‐term outcomes of liver transplantation (LT) for patients with hepatocellular carcinoma (HCC) and to assess whether it is justified to continue the policy of assigning increased priority for candidates with early‐stage HCC on the transplant waiting list in the United States. The objectives of the conference were to address specific HCC issues as they relate to liver allocation, develop a standardized pathology report form for the assessment of the explanted liver, develop more specific imaging criteria for HCC designed to qualify LT candidates for automatic Model for End‐Stage Liver Disease (MELD) exception points without the need for biopsy, and develop a standardized pretransplant imaging report form for the assessment of patients with liver lesions. At the completion of the meeting, there was agreement that the allocation policy should result in similar risks of removal from the waiting list and similar transplant rates for HCC and non‐HCC candidates. In addition, the allocation policy should select HCC candidates so that there are similar posttransplant outcomes for HCC and non‐HCC recipients. There was a general consensus for the development of a calculated continuous HCC priority score for ranking HCC candidates on the list that would incorporate the calculated MELD score, alpha‐fetoprotein, tumor size, and rate of tumor growth. Only candidates with at least stage T2 tumors would receive additional HCC priority points. Liver Transpl 16:262–278, 2010.

The effect of the volume of procedures at transplantation centers on mortality after liver transplantation.

Background For many complex surgical procedures there is an association between a low volume of procedures and an increased risk of death for the patients who undergo the procedures. Methods We examined the effect of the volume of procedures at transplantation centers on the risk of death after liver transplantation. We analyzed all liver transplantations performed in the United States between October 1, 1987, and April 30, 1994. Because the results for 1987 to 1991 were largely similar to those from 1992 to 1994, we focused on the more recent period. Results Between January 1, 1992, and April 30, 1994, 47 centers performed 20 or fewer liver transplantations each per year (total, 837 transplantations) and were designated low-volume centers, and 52 centers performed more than 20 transplantations each per year (total, 6526) and were designated high-volume centers. The one-year mortality rate for the low-volume centers was 25.9 percent, as compared with 20.0 percent for the high-volume centers. Thirteen cent...

Liver transplantation for hepatocellular carcinoma: The MELD impact

The new allocation policy of the United Network of Organ Sharing (UNOS) based on the model for end‐stage liver disease (MELD) gives candidates with stage T1 or stage T2 hepatocellular carcinoma (HCC) a priority MELD score beyond their degree of hepatic decompensation. The aim of this study was to determine the impact of the new allocation policy on HCC candidates before and after the institution of MELD. The UNOS database was reviewed for all HCC candidates listed between July 1999 and July 2002. The candidates were grouped by two time periods, based on the date of implementation of new allocation policy of February 27, 2002. Pre‐MELD candidates were listed for deceased donor liver transplantation (DDLT) before February 27,2002, and post‐MELD candidates were listed after February 27, 2002. Candidates were compared by incidence of DDLT, time to DDLT, and dropout rate from the waiting list because of clinical deterioration or death, and survival while waiting and after DDLT. Incidence rates calculated for pre‐MELD and post‐MELD periods were expressed in person years. During the study, 2,074 HCC candidates were listed for DDLT in the UNOS database. The DDLT incidence rate was 0.439 transplant/person years pre‐MELD and 1.454 transplant/person years post‐MELD (P < 0.001). The time to DDLT was 2.28 years pre‐MELD and 0.69 years post‐MELD (P < 0.001). The 5‐month dropout rate was 16.5% pre‐MELD and 8.5% post‐MELD (P < 0.001). The 5‐month waiting‐list survival was 90.3% pre‐MELD and 95.7% post‐MELD (P < 0.001). The 5‐month survival after DDLT was similar for both time periods. The new allocation policy has led to an increased incidence rate of DDLT in HCC candidates. Furthermore, the 5‐month dropout rate has decreased significantly. In addition, 5‐month survival while waiting has increased in the post‐MELD period. Thus, the new MELD‐based allocation policy has benefited HCC candidates. (Liver Transpl 2004;10:36–41.)

OPTN/SRTR 2013 Annual Data Report: Liver: OPTN/SRTR 2013 Annual Data Report: Liver

During 2013, 10,479 adult candidates were added to the liver transplant waiting list, compared with 10,185 in 2012; 5921 liver transplants were performed, and 211 of the transplanted organs were from living donors. As of December 31, 2013, 15,027 candidates were registered on the waiting list, including 12,407 in active status. The most significant change in allocation policy affecting liver waitlist trends in 2013 was the Share 35 policy, whereby organs from an entire region are available to candidates with model for end‐stage liver disease scores of 35 or higher. Median waiting time for such candidates decreased dramatically, from 14.0 months in 2012 to 1.4 months in 2013, but the effect on waitlist mortality is unknown. The number of new active pediatric candidates added to the liver transplant waiting list increased to 693 in 2013. Transplant rates were highest for candidates aged younger than 1 year (275.6 per 100 waitlist years) and lowest for candidates aged 11 to 17 years (97.0 per 100 waitlist years). Five‐year graft survival was 71.7% for recipients aged younger than 1 year, 74.9% for ages 1 to 5 years, 78.9% ages 6 to 10 years, and 77.4% for ages 11 to 17 years.

Hepatocellular Carcinoma Patients Are Advantaged in the Current Liver Transplant Allocation System

Patients with hepatocellular carcinoma (HCC) within Milan criteria receive priority on the liver transplant waiting list (WL) and compete with non‐HCC patients. Dropout from the WL is an indirect measure of transplant access. Competing risks (CR) evaluation of dropout for HCC and non‐HCC patients has not previously been reported. Patients listed between 16 March 2005 and 30 June 2008 were included. Probability of dropout was estimated using a CR technique as well as a Cox model for time to dropout. Overall, non‐HCC patients had a higher dropout rate from the WL than HCC patients (p < 0.0001). This was reproducible throughout all regions. In Cox regression, tumor size, model for end‐stage liver disease (MELD) score and alpha fetoprotein (AFP) were associated with increased dropout risk. Multivariable analysis with CR showed that MELD score and AFP, were most influential in predicting dropout for HCC patients. The index of concordance for predicting dropout with the CR was 0.70. HCC patients appear to be advantaged in the current allocation scheme based on lower dropout rates without regard to geography. A continuous score incorporating MELD, AFP and tumor size may help to prioritize HCC patients to better equate dropout rates with non‐HCC patients and equalize access.