Patient-specific prediction of ESRD after liver transplantation.

Incident ESRD after liver transplantation (LT) is associated with high post-transplant mortality. We constructed and validated a continuous renal risk index (RRI) to predict post-LT ESRD. Data for 43,514 adult recipients of deceased donor LT alone (February 28, 2002 to December 31, 2010) were linked from the Scientific Registry of Transplant Recipients and the Centers for Medicare and Medicaid Services ESRD Program. An adjusted Cox regression model of time to post-LT ESRD was fitted, and the resulting equation was used to calculate an RRI for each LT recipient. The RRI included 14 recipient factors: age, African-American race, hepatitis C, cholestatic disease, body mass index ≥ 35, pre-LT diabetes, ln creatinine for recipients not on dialysis, ln albumin, ln bilirubin, serum sodium<134 mEq/L, status-1, previous LT, transjugular intrahepatic portosystemic shunt, and acute dialysis at LT. This RRI was validated and had a C statistic of 0.76 (95% confidence interval, 0.75 to 0.78). Higher RRI associated significantly with higher 5-year cumulative incidence of ESRD and post-transplant mortality. In conclusion, the RRI constructed in this study quantifies the risk of post-LT ESRD and is applicable to all LT alone recipients. This new validated measure may serve as an important prognostic tool in ameliorating post-LT ESRD risk and improve survival by informing post-LT patient management strategies.

Factors that affect deceased donor liver transplantation rates in the United States in addition to the Model for End-stage Liver Disease score.

Under an ideal implementation of Model for End-Stage Liver Disease (MELD)-based liver allocation, the only factors that would predict deceased donor liver transplantation (DDLT) rates would be the MELD score, blood type, and donation service area (DSA). We aimed to determine whether additional factors are associated with DDLT rates in actual practice. Data from the Scientific Registry of Transplant Recipients for all adult candidates wait-listed between March 1, 2002 and December 31, 2008 (n = 57,503) were analyzed. Status 1 candidates were excluded. Cox regression was used to model covariate-adjusted DDLT rates, which were stratified by the DSA, blood type, liver-intestine policy, and allocation MELD score. Inactive time on the wait list was not modeled, so the computed DDLT hazard ratios (HRs) were interpreted as active wait-list candidates. Many factors, including the candidate's age, sex, diagnosis, hospitalization status, and height, prior DDLT, and combined listing for liver-kidney or liver-intestine transplantation, were significantly associated with DDLT rates. Factors associated with significantly lower covariate-adjusted DDLT rates were a higher serum creatinine level (HR = 0.92, P < 0.001), a higher bilirubin level (HR = 0.99, P = 0.001), and the receipt of dialysis (HR = 0.83, P < 0.001). Mild ascites (HR = 1.15, P < 0.001) and hepatic encephalopathy (grade 1 or 2, HR = 1.05, P = 0.02; grade 3 or 4, HR = 1.10, P = 0.01) were associated with significantly higher adjusted DDLT rates. In conclusion, adjusted DDLT rates for actively listed candidates are affected by many factors aside from those integral to the allocation system; these factors include the components of the MELD score itself as well as candidate factors that were considered but were deliberately omitted from the MELD score in order to keep it objective. These results raise the question whether additional candidate characteristics should be explicitly incorporated into the prioritization of wait-list candidates because such factors are already systematically affecting DDLT rates under the current allocation system.

Portal vein thrombosis and liver transplant survival benefit.

Portal vein thrombosis (PVT) complicates the liver transplant operation and potentially affects waiting list survival. The implications on calculations of survival benefit, which balance both waiting list and posttransplant survival effects of PVT, have not been determined. The objective of this study is to describe the effect of PVT on the survival benefit of liver transplantation. Using Scientific Registry of Transplant Recipients data on adult liver transplant candidates wait-listed between September 2001 and December 2007, Cox proportional hazard models were fitted to estimate the covariate-adjusted effect of PVT on transplant rate, waiting list survival, and posttransplant survival. We then used sequential stratification to estimate liver transplant survival benefit by cross-classifications defined by Model for End-Stage Liver Disease (MELD) score and PVT status. The prevalence of reported PVT among 22,291 liver transplant recipients was 4.02% (N = 897). PVT was not a predictor of waiting list mortality (hazard ratio = 0.90, P = 0.23) but was a predictor of posttransplant mortality (hazard ratio = 1.32, P = 0.02). Overall, transplant benefit was not significantly different for patients with PVT versus without PVT (P = 0.21), but there was a shift in the benefit curve. Specifically, the threshold for transplant benefit among patients without PVT was MELD score >11 compared to MELD score >13 for patients with PVT. PVT is associated with significantly higher posttransplant mortality but does not affect waiting list mortality. Among patients with low MELD score, PVT is associated with less transplant survival benefit. Clinicians should carefully consider the risks of liver transplantation in clinically stable patients who have PVT.

Racial and ethnic disparities in access to liver transplantation.

Access to liver transplantation is reportedly inequitable for racial/ethnic minorities, but inadequate adjustments for geography and disease progression preclude any meaningful conclusions. We aimed to evaluate the association between candidate race/ethnicity and liver transplant rates after thorough adjustments for these factors and to determine how uniform racial/ethnic disparities were across Model for End-Stage Liver Disease (MELD) scores. Chronic end-stage liver disease candidates initially wait-listed between February 28, 2002 and February 27, 2007 were identified from Scientific Registry for Transplant Recipients data. The primary outcome was deceased donor liver transplantation (DDLT); the primary exposure covariate was race/ethnicity (white, African American, Hispanic, Asian, and other). Cox regression was used to estimate the covariate-adjusted DDLT rates by race/ethnicity, which were stratified by the donation service area and MELD score. With averaging across all MELD scores, African Americans, Asians, and others had similar adjusted DDLT rates in comparison with whites. However, Hispanics had an 8% lower DDLT rate versus whites [hazard ratio (HR) = 0.92, P = 0.011]. The disparity among Hispanics was concentrated among patients with MELD scores < 20, with HR = 0.84 (P = 0.021) for MELD scores of 6 to 14 and HR = 0.85 (P = 0.009) for MELD scores of 15 to 19. Asians with MELD scores < 15 had a 24% higher DDLT rate with respect to whites (HR = 1.24, P = 0.024). However, Asians with MELD scores of 30 to 40 had a 46% lower DDLT rate (HR = 0.54, P = 0.004). In conclusion, although African Americans did not have significantly different DDLT rates in comparison with similar white candidates, race/ethnicity-based disparities were prominent among subgroups of Hispanic and Asian candidates. By precluding the survival benefit of liver transplantation, this inequity may lead to excess mortality for minority candidates.

Effect of alcoholic liver disease and hepatitis C infection on waiting list and posttransplant mortality and transplant survival benefit.

UNLABELLED: Disease-specific analysis of liver transplant survival benefit, which encompasses both pre- and posttransplant events, has not been reported. Therefore, we evaluated the effect of alcoholic liver disease (ALD) and hepatitis C virus (HCV) infection on waiting list mortality, posttransplant mortality, and the survival benefit of deceased donor liver transplantation using United States data from the Scientific Registry of Transplant Recipients on 38,899 adults placed on the transplant waiting list between September 2001 and December 2006. Subjects were classified according to the presence/absence of HCV and ALD. Cox regression was used to estimate waiting list mortality and posttransplant mortality separately. Survival benefit was assessed using sequential stratification. Overall, the presence of HCV significantly increased waiting list mortality, with a covariate-adjusted hazard ratio (HR) for HCV-positive (HCV+) compared with HCV-negative (HCV-) HR = 1.19 (P = 0.0001). The impact of HCV+ was significantly more pronounced (P = 0.001) among ALD-positive (ALD+) patients (HR = 1.36; P < 0.0001), but was still significant among ALD-negative (ALD-) patients (HR = 1.11; P = 0.02). The contrast between ALD+ and ALD- waiting list mortality was significant only among HCV+ patients (HR = 1.14; P = 0.006). Posttransplant mortality was significantly increased among HCV+ (versus HCV-) patients (HR = 1.26; P = 0.0009), but not among ALD+ (versus ALD-) patients. Survival benefit of transplantation was significantly decreased among HCV+ compared with HCV- recipients with model for end-stage liver disease (MELD) scores 9-29, but was significantly increased at MELD >or=30. ALD did not influence the survival benefit of transplantation at any MELD score. CONCLUSION: Except in patients with very low or very high MELD scores, HCV status has a significant negative impact on the survival benefit of liver transplantation. In contrast, the presence of ALD does not influence liver transplant survival benefit.

Effect of pretransplant serum creatinine on the survival benefit of liver transplantation.

More candidates with creatinine levels >or= 2 mg/dL have undergone liver transplantation (LT) since the implementation of Model for End-Stage Liver Disease (MELD)-based allocation. These candidates have higher posttransplant mortality. This study examined the effect of serum creatinine on survival benefit among candidates undergoing LT. Scientific Registry of Transplant Recipients data were analyzed for adult LT candidates listed between September 2001 and December 2006 (n = 38,899). The effect of serum creatinine on survival benefit (contrast between waitlist and post-LT mortality rates) was assessed by sequential stratification, an extension of Cox regression. At the same MELD score, serum creatinine was inversely associated with survival benefit within certain defined MELD categories. The survival benefit significantly decreased as creatinine increased for candidates with MELD scores of 15 to 17 or 24 to 40 at LT (MELD scores of 15-17, P < 0.0001; MELD scores of 24-40, P = 0.04). Renal replacement therapy at LT was also associated with significantly decreased LT benefit for patients with MELD scores of 21 to 23 (P = 0.04) or 24 to 26 (P = 0.01). In conclusion, serum creatinine at LT significantly affects survival benefit for patients with MELD scores of 15 to 17 or 24 to 40. Given the same MELD score, patients with higher creatinine levels receive less benefit on average, and the relative ranking of a large number of wait-listed candidates with MELD scores of 15 to 17 or 24 to 40 would be markedly affected if these findings were incorporated into the allocation policy.

Rates of solid-organ wait-listing, transplantation, and survival among residents of rural and urban areas.

CONTEXT: Disparities in access to organ transplantation exist for racial minorities, women, and patients with lower socioeconomic status or inadequate insurance. Rural residents represent another group that may have impaired access to transplant services. OBJECTIVE: To assess the association of rural residence with waiting list registration for heart, liver, and kidney transplant and rates of transplantation among wait-listed candidates. DESIGN, SETTING, AND PATIENTS: Five-year US cohort of 174,630 patients who were wait-listed and who underwent heart, liver, or kidney transplantation between 1999 and 2004. MAIN OUTCOME MEASURES: Rates of new waiting list registrations and transplants per million population for residents of 3 residential classifications (rural/small town population, <10,000; micropolitan, 10,000-50,000; and metropolitan >50,000 or suburb of major city). RESULTS: Compared with urban residents, waiting list registration rates for rural/small town residents were significantly lower for heart (covariate-adjusted rate ratio [RR] = 0.91; 95% confidence interval [CI], 0.86-0.96; P<.002), liver (RR = 0.86; 95% CI, 0.83-0.89; P<.001), and kidney transplants (RR = 0.92; 95% CI, 0.90-0.95; P<.001). Compared with residents in urban areas, rural/small town residents had lower relative transplant rates for heart (RR = 0.88; 95% CI, 0.81-0.94; P = .004), liver (RR = 0.80; 95% CI, 0.77-0.84; P<.001), and kidney transplantation (covariate-adjusted RR = 0.90; 95% CI, 0.88-0.93; P<.001). These disparities were consistent across national organ allocation regions. Significantly longer waiting times among rural patients wait-listed for heart transplantation were observed but not for liver and kidney transplantation. There were no significant differences in posttransplantation outcomes between groups. CONCLUSIONS: Patients living in rural areas had a lower rate of wait-lisiting and transplant of solid organs, but did not experience significantly different outcomes following transplant. Differences in rates of wait-listing and transplant may be due to variations in the burden of disease between different patient groups or barriers to evaluation and waiting list entry for rural residents with organ failure.

Impact of the expanded criteria donor allocation system on candidates for and recipients of expanded criteria donor kidneys.

BACKGROUND: A national policy to allocate kidneys from expanded criteria donors (ECD) took effect October 31, 2002. METHODS: To assess its impact, we analyzed data from the Scientific Registry of Transplant Recipients for ECD kidney candidates and recipients between November 1999 and October 2005. RESULTS: The likelihood of being listed for ECD transplant, of receiving any transplant, and of receiving an ECD transplant were assessed using logistic regression models. As of October 31, 2005, 42.6% of candidates were listed with an ECD designation (range by donation service area [DSA], 1.9% to 94.9%). ECD-listed candidates were likely to be older, diabetic, and sensitized. By October 31, 2005, candidates listed for ECD as of November 1, 2002 were 41% more likely to receive any kidney transplant than those not ECD-listed. Among ECD-listed recipients, 30.1% received an ECD transplant and 69.9% a non-ECD transplant. Recipients more likely to receive an ECD transplant were significantly older and in DSAs where a high percentage of ECD transplants were performed and/or a low percentage of candidates were ECD-listed. CONCLUSIONS: A large, regionally variable fraction of candidates are opting to receive ECD offers. Listing with an ECD designation increases the likelihood of transplantation in selected populations. Selective listing of ECD candidates is associated with a higher likelihood of receiving an ECD transplant.

The rationale for the new deceased donor pancreas allocation schema.

BACKGROUND: To ensure the continued success of whole organ pancreas and islet transplantation, deceased donor pancreas allocation policy must continue to evolve. METHODS: To assess the existing system, the Organ Procurement and Transplantation Network (OPTN)/United Network for Organ Sharing Kidney and Pancreas Transplant Committee retrospectively analyzed the disposition and outcomes of deceased donor pancreata in the United States between January 1, 2000 and December 31, 2003. RESULTS: During the time period studied, consent was obtained but the pancreas was not recovered in 48% (11,820) of organ donors. The most common reasons given for nonrecovery were poor quality of the pancreas and difficulty in placement. Of whole organ pancreata that were transplanted, 90% were from donors with a body mass index (BMI) 50 years (P=0.04), and there were trends toward lower graft survival with donor BMI >30 (P=0.06) and increasing cold-ischemia time. CONCLUSIONS: Based on these data, the OPTN adopted a new allocation algorithm in which pancreata from donors >30 kg/m or >50 years of age are, unless accepted for a local whole organ pancreas transplant candidate, preferentially allocated for islet transplantation. These data also suggest that many good quality pancreata are not procured, emphasizing the need for improved communication and cooperation between organ procurement organizations and pancreas and islet transplant programs.

Impact of the expanded criteria donor allocation system on the use of expanded criteria donor kidneys.

BACKGROUND: The U.S. Organ Procurement and Transplantation Network recently implemented a policy allocating expanded criteria donor (ECD) kidneys by waiting time alone. ECD kidneys were defined as having a risk of graft failure > or = 1.7 times that of ideal donors. ECDs include any donor > or = 60 years old and donors 50 to 59 years old with at least two of the following: terminal creatinine >1.5 mg/dL, history of hypertension, or death by cerebrovascular accident. The impact of this policy on use of ECD kidneys is assessed. METHODS: The authors compared use of ECD kidneys recovered in the 18 months immediately before and after policy implementation. Differences were tested using t test and chi2 analyses. RESULTS: There was an 18.3% increase in ECD kidney recoveries and a 15.0% increase in ECD kidney transplants in the first 18 months after policy implementation. ECD kidneys made up 22.1% of all recovered kidneys and 16.8% of all transplants, compared with 18.8% (P<0.001) and 14.5% (P<0.001), respectively, in the prior period. The discard rate was unchanged. The median relative risk (RR) for graft failure for transplanted ECD kidneys was 2.07 versus 1.99 in the prepolicy period (P=not significant); the median RR for procured ECD kidneys was unchanged at 2.16. The percentage of transplanted ECD kidneys with cold ischemia times (CIT) <12 hr increased significantly; the corresponding percentage for CIT > or = 24 hr decreased significantly. CONCLUSIONS: The recent increase in ECD kidney recoveries and transplants appears to be related to implementation of the ECD allocation system.

Disparities in liver transplantation: the association between donor quality and recipient race/ethnicity and sex.

BACKGROUND: We aimed to examine the association between recipient race/ethnicity and sex, donor liver quality, and liver transplant graft survival. METHODS: Adult non-status 1 liver recipients transplanted between March 1, 2002, and December 31, 2008, were identified using Scientific Registry of Transplant Recipients data. The factors of interest were recipient race/ethnicity and sex. Donor risk index (DRI) was used as a donor quality measure. Logistic regression was used to assess the association between race/ethnicity and sex in relation to the transplantation of low-quality (high DRI) or high-quality (low DRI) livers. Cox regression was used to assess the association between race/ethnicity and sex and liver graft failure risk, accounting for DRI. RESULTS: Hispanics were 21% more likely to receive low-quality grafts compared to whites (odds ratio [OR]=1.21, P=0.002). Women had greater odds of receiving a low-quality graft compared to men (OR=1.24, P<0.0001). Despite adjustment for donor quality, African American recipients still had higher graft failure rates compared to whites (hazard ratio [HR]=1.28, P<0.001). Hispanics (HR=0.89, P=0.023) had significantly lower graft failure rates compared to whites despite higher odds of receiving a higher DRI graft. Using an interaction model of DRI and race/ethnicity, we found that the impact of DRI on graft failure rates was significantly reduced for African Americans compared to whites (P=0.02). CONCLUSIONS: This study shows that while liver graft quality differed significantly by recipient race/ethnicity and sex, donor selection practices do not seem to be the dominant factor responsible for worse liver transplant outcomes for minority recipients.

Short-term pretransplant renal replacement therapy and renal nonrecovery after liver transplantation alone.

BACKGROUND AND OBJECTIVES: Candidates with AKI including hepatorenal syndrome often recover renal function after successful liver transplantation (LT). This study examined the incidence and risk factors associated with renal nonrecovery within 6 months of LT alone among those receiving acute renal replacement therapy (RRT) before LT. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Scientific Registry of Transplant Recipients data were linked with Centers for Medicare and Medicaid Services ESRD data for 2112 adult deceased-donor LT-alone recipients who received acute RRT for ≤90 days before LT (February 28, 2002 to August 31, 2010). Primary outcome was renal nonrecovery (post-LT ESRD), defined as transition to chronic dialysis or waitlisting or receipt of kidney transplant within 6 months of LT. Cumulative incidence of renal nonrecovery was calculated using competing risk analysis. Cox regression identified recipient and donor predictors of renal nonrecovery. RESULTS: The cumulative incidence of renal nonrecovery after LT alone among those receiving the pre-LT acute RRT was 8.9%. Adjusted renal nonrecovery risk increased by 3.6% per day of pre-LT RRT (P<0.001). Age at LT per 5 years (P=0.02), previous-LT (P=0.01), and pre-LT diabetes (P<0.001) were significant risk factors of renal nonrecovery. Twenty-one percent of recipients died within 6 months of LT. Duration of pretransplant RRT did not predict 6-month post-transplant mortality. CONCLUSIONS: Among recipients on acute RRT before LT who survived after LT alone, the majority recovered their renal function within 6 months of LT. Longer pre-LT RRT duration, advanced age, diabetes, and re-LT were significantly associated with increased risk of renal nonrecovery.

A comprehensive risk quantification score for deceased donor kidneys: the kidney donor risk index.

BACKGROUND: We propose a continuous kidney donor risk index (KDRI) for deceased donor kidneys, combining donor and transplant variables to quantify graft failure risk. METHODS: By using national data from 1995 to 2005, we analyzed 69,440 first-time, kidney-only, deceased donor adult transplants. Cox regression was used to model the risk of death or graft loss, based on donor and transplant factors, adjusting for recipient factors. The proposed KDRI includes 14 donor and transplant factors, each found to be independently associated with graft failure or death: donor age, race, history of hypertension, history of diabetes, serum creatinine, cerebrovascular cause of death, height, weight, donation after cardiac death, hepatitis C virus status, human leukocyte antigen-B and DR mismatch, cold ischemia time, and double or en bloc transplant. The KDRI reflects the rate of graft failure relative to that of a healthy 40-year-old donor. RESULTS: Transplants of kidneys in the highest KDRI quintile (>1.45) had an adjusted 5-year graft survival of 63%, compared with 82% and 79% in the two lowest KDRI quintiles (<0.79 and 0.79-<0.96, respectively). There is a considerable overlap in the KDRI distribution by expanded and nonexpanded criteria donor classification. CONCLUSIONS: The graded impact of KDRI on graft outcome makes it a useful decision-making tool at the time of the deceased donor kidney offer.

Pediatric transplantation, 1994-2003.

This article uses OPTN/SRTR data to review trends in pediatric transplantation over the last decade. In 2003, children younger than 18 made up 3% of the 82,885 candidates for organ transplantation and 7% of the 25,469 organ transplant recipients. Children accounted for 14% of the 6,455 deceased organ donors. Pediatric organ transplant recipients differ from their adult counterparts in several important aspects, including the underlying etiology of organ failure, the complexity of the surgical procedures, the pharmacokinetic properties of common immunosuppressants, the immune response following transplantation, the number and degree of comorbid conditions, and the susceptibility to post-transplant complications, especially infectious diseases. Specialized pediatric organ transplant programs have been developed to address these special problems. The transplant community has responded to the particular needs of children and has provided them special consideration in the allocation of deceased donor organs. As a result of these programs and protocols, children are now frequently the most successful recipients of organ transplantation; their outcomes following kidney, liver, and heart transplantation rank among the best. This article demonstrates that substantial improvement is needed in several areas: adolescent outcomes, outcomes following intestine transplants, and waiting list mortality among pediatric heart and lung candidates.

Development and current status of ECD kidney transplantation.

The worsening shortage of donor kidneys for transplant and the aging of both the donor and candidate populations have contributed to the increasing importance of ECD kidney transplantation. While ECD transplants have an increased risk of graft failure, for most candidates patient survival is still improved over remaining on dialysis. Because of this risk, however, ECD kidneys have a high likelihood of discard; significant geographic variation in discard and transplant rates impedes maximum utilization of these kidneys. The ECD allocation system was implemented to help facilitate expeditious placement of ECD kidneys to pre-consented candidates by a simplified allocation algorithm. Under this system, recovery and transplantation of ECD kidneys have increased at rates not seen with non-ECD kidneys and not predicted by preexisting trends. More disappointing has been the lack of effect on the percentage of discards and DGF, despite significant reductions in CIT. The disadvantage in graft survival for ECD kidneys extends equally across the spectrum of recipient characteristics, such that no one group of candidates has a proportionately smaller increase in risk. However, benefit analyses comparing the risk of accepting an ECD kidney versus waiting for a non-ECD kidney demonstrate a significant ECD benefit for older and diabetic candidates in regions with prolonged waiting times. The potential value of an ECD kidney to an individual candidate hinges upon the ability to receive it substantially earlier than a non-ECD kidney. Thus, future allocation efforts may focus on ensuring that is the case. In allocation driven by net benefit, ECD kidneys may become an alternative for those who might not otherwise receive a kidney transplant.

Prevalence and outcomes of multiple-listing for cadaveric kidney and liver transplantation.

Transplant candidates are permitted to register on multiple waiting lists. We examined multiple-listing practices and outcomes, using data on 81 481 kidney and 26 260 liver candidates registered between 7/1/95 and 6/30/00. Regression models identified factors associated with multiple-listing and its effect on relative rates of transplantation, waiting list mortality, kidney graft failure, and liver transplant mortality. Overall, 5.8% (kidney) and 3.3% (liver) of candidates multiple-listed. Non-white race, older age, non-private insurance, and lower educational level were associated with significantly lower odds of multiple-listing. While multiple-listed, transplantation rates were significantly higher for nearly all kidney and liver candidate subgroups (relative rate [RR]= 1.42-2.29 and 1.82-7.41, respectively). Waiting list mortality rates were significantly lower while multiple-listed for 11 kidney subgroups (RR = 0.22-0.72) but significantly higher for 7 liver subgroups (RR = 1.44-5.93), suggesting multiple-listing by healthier kidney candidates and sicker liver candidates. Graft failure was 10% less likely among multiple-listed kidney recipients. Multiple- and single-listed liver recipients had similar post-transplant mortality rates. Although specific factors characterize those transplant candidates likely to multiple-list, transplant access is significantly enhanced for almost all multiple-listed kidney and liver candidates.

Association of center volume with outcome after liver and kidney transplantation.

Outcomes for certain surgical procedures have been linked with volume: hospitals performing a high number of procedures demonstrate better outcomes than do low-volume centers. This study examines the effect of volume on hepatic and renal transplant outcomes. Data from the Scientific Registry of Transplant Recipients were analyzed for transplants performed from 1996-2000. Transplant centers were assigned to volume quartiles (kidney) or terciles (liver). Logistic regression models, adjusted for clinical characteristics and transplant center clustering, demonstrate the effect of transplant center volume quantile on 1-year post-transplant patient mortality (liver) and graft loss (kidney). The unadjusted rate of renal graft loss within 1 year was significantly lower at high volume centers (8.6%) compared with very low (9.6%), low (9.9%) and medium (9.7%) volume centers (p = 0.0014). After adjustment, kidney transplant at very low [adjusted odds ratio (AOR) 1.22; p = 0.043) and low volume (AOR 1.22 p = 0.041) centers was associated with a higher incidence of graft loss when compared with high volume centers. Unadjusted 1-year mortality rates for liver transplant were significantly different at high (15.9%) vs. low (16.9%) or medium (14.7%) volume centers. After adjustment, low volume centers were associated with a significantly higher risk of death (AOR 1.30; p = 0.0036). There is considerable variability in the range of failure between quantiles after kidney and liver transplant. Transplant outcomes are better at high volume centers; however, there is no clear minimal threshold volume.

Organ donation and utilization in the USA.

The processes leading to donor identification, consent, organ procurement, and allocation continue to dominate debates and efforts in the field of transplantation. A considerable shortage of donors remains while the number of patients needing organ transplantation increases. This article reviews the main trends in organ donation practices and procurement patterns from both deceased and living sources in the USA. Although there have been increases in living donation in recent years, 2002 witnessed a much more modest growth of 1%. Absolute declines in living liver and lung donation were also noted in 2002. In 2002, the number of deceased donors increased by only 1.6% (101 donors). Increased donation from deceased donors provides more organs for transplantation than a comparable increase in living donation, because on average 3.6 organs are recovered from each deceased donor. The total number of organs recovered from deceased donors increased by 2.1% (462 organs). Poor organ quality continued to be the major reason given for nonrecovery of consented organs from deceased donors. The kidney is the organ most likely to be discarded after recovery. Over the past decade the discard rate of recovered kidneys has increased from 6% to 11%. Many of these are expanded criteria donor kidneys.