Faculty Bibliography

Currently, there is debate among the liver transplant community regarding the most appropriate mechanism for organ allocation: urgency-based (MELD) versus utility-based (survival benefit). We hypothesize that MELD and survival benefit are closely associated, and therefore, our current MELD-based allocation already reflects utility-based allocation. We used generalized gamma parametric models to quantify survival benefit of LT across MELD categories among 74 196 adult liver-only active candidates between 2006 and 2016 in the United States. We calculated time ratios (TR) of relative life expectancy with transplantation versus without and calculated expected life years gained after LT. LT extended life expectancy (TR > 1) for patients with MELD > 10. The highest MELD was associated with the longest relative life expectancy (TR = _1.05 1.20_1.37 for MELD 11-15, _2.29 2.49_2.70 for MELD 16-20, _5.30 5.72_6.16 for MELD 21-25, _15.12 16.35_17.67 for MELD 26-30; _39.26 43.21_47.55 for MELD 31-34; _120.04 128.25_137.02 for MELD 35-40). As a result, candidates with the highest MELD gained the most life years after LT: 0.2, 1.5, 3.5, 5.8, 6.9, 7.2 years for MELD 11-15, 16-20, 21-25, 26-30, 31-34, 35-40, respectively. Therefore, prioritizing candidates by MELD remains a simple, effective strategy for prioritizing candidates with a higher transplant survival benefit over those with lower survival benefit.

The Kidney Allocation System (KAS) was implemented in December 2014 with unknown impact on the pediatric waitlist. To understand the effect of KAS on pediatric registrants, deceased donor kidney transplant (DDKT) rate was assessed using interrupted time series analysis and time-to-event analysis. Two allocation eras were defined with an intermediary washout period: Era 1 (01/01/2013-09/01/2014), Era 2 (09/01/2014-03/01/2015), and Era 3(03/01/2015-03/01/2017). When using Cox proportional hazards, there was no significant association between allocation era and DDKT likelihood as compared to Era 1 (Era 3: aHR: 1.07, 95% CI: 0.97-1.18, P = .17). However, this was not consistent across all subgroups. Specifically, while highly sensitized pediatric registrants were consistently less likely to be transplanted than their less sensitized counterparts, this disparity was attenuated in Era 3 (Era 1 aHR: 0.04, 95%CI: 0.01-0.14, P < .001; Era 3 aHR: 0.33, 95% CI: 0.21-0.53, P < .001) whereas the youngest registrants aged 0-6 experienced a 21% decrease in DDKT likelihood in Era 3 as compared to Era 1 (aHR: 0.79, 95% CI: 0.64-0.98, P = .03). Thus, while overall DDKT likelihood remained stable with the introduction of KAS, registrants ≤ 6 years of age were disadvantaged, warranting further study to ensure equitable access to transplantation.

Kidney paired donation (KPD) can facilitate living donor transplantation for candidates with an incompatible donor, but requires waiting for a match while experiencing the morbidity of dialysis. The balance between waiting for KPD vs desensitization or deceased donor transplantation relies on the ability to estimate KPD wait times. We studied donor/candidate pairs in the National Kidney Registry (NKR), a large multicenter KPD clearinghouse, between October 2011 and September 2015 using a competing-risk framework. Among 1894 candidates, 52% were male, median age was 50 years, 66% were white, 59% had blood type O, 42% had panel reactive antibody (PRA)>80, and 50% obtained KPD through NKR. Median times to KPD ranged from 2 months for candidates with ABO-A and PRA 0, to over a year for candidates with ABO-O or PRA 98+. Candidates with PRA 80-97 and 98+ were 23% (95% confidence interval , 6%-37%) and 83% (78%-87%) less likely to be matched than PRA 0 candidates. ABO-O candidates were 67% (61%-73%) less likely to be matched than ABO-A candidates. Candidates with ABO-B or ABO-O donors were 31% (10%-56%) and 118% (82%-162%) more likely to match than those with ABO-A donors. Providers should counsel candidates about realistic, individualized expectations for KPD, especially in the context of their alternative treatment options.

Background:The use of machine perfusion (MP) in kidney transplantation lowers delayed graft function (DGF) and improves 1-year graft survival in some, but not all, grafts. These associations have not been explored in grafts stratified by the Kidney Donor Profile index (KDPI). Methods:We analyzed 78 207 deceased-donor recipients using the Scientific Registry of Transplant Recipients data from 2006 to 2013. The cohort was stratified using the standard criteria donor/expanded criteria donor (ECD)/donation after cardiac death (DCD)/donation after brain death (DBD) classification and the KDPI scores. In each subgroup, MP use was compared with cold storage. Results:The overall DGF rate was 25.4% and MP use was associated with significantly lower DGF in all but the ECD-DCD donor subgroup. Using the donor source classification, the use of MP did not decrease death-censored graft failure (DCGF), except in the ECD-DCD subgroup from 0 to 1 year {adjusted hazard ratio [aHR] 0.56 [95% confidence interval (CI) 0.32-0.98]}. In the ECD-DBD subgroup, higher DCGF from 1 to 5 years was noted [aHR 1.15 (95% CI 1.01-1.31)]. Also, MP did not lower all-cause graft failure except in the ECD-DCD subgroup from 0 to 1 year [aHR = 0.59 (95% CI 0.38-0.91)]. Using the KDPI classification, MP did not lower DCGF or all-cause graft failure, but in the ≤70 subgroup, higher DCGF [aHR 1.16 (95% CI 1.05-1.27)] and higher all-cause graft failure [aHR 1.10 (95% CI 1.02-1.18)] was noted. Lastly, MP was not associated with mortality in any subgroup. Conclusions:Overall, MP did not lower DCGF. Neither classification better risk-stratified kidneys that have superior graft survival with MP. We question their widespread use in all allografts as an ideal approach to organ preservation.

BACKGROUND:Allografts from older liver donors (OLDs), 70 years or older are often discarded for fear of inferior outcomes. We previously identified "preferred recipients" who did not suffer the higher risk of graft loss and mortality associated with OLDs. Preferred recipients were first-time, non-status 1 registrants older than 45 years, body mass index less than 35, indication other than hepatitis C, and cold ischemia time less than 8 hours. METHODS:We assessed the validity of the preferred recipient construct in a larger, more recent cohort (38 891 patients, 2006-2013). We compared recipients of OLD grafts to recipients of average liver donors (ALDs, age = 40-69) and ideal liver donors (ILDs, age = 18-39) grafts using multilevel Cox regression adjusting for recipient and transplant factors. RESULTS:The use of OLD grafts in preferred recipients has increased from 2006 to 2013 (P = 0.02). Preferred recipients Model for End-Stage Liver Disease scores ranged 6 to 40. Preferred recipients had similar 5-year all-cause graft loss (ACGL) with OLD versus ALD and ILD grafts (25.4% vs 24.5% and 21.6%). Conversely, nonpreferred recipients had higher 5-year ACGL with OLD versus ALD and ILD grafts (41.4% vs 32.9% and 25.6%). After adjustment, preferred recipients had similar graft loss with OLD versus ALD grafts (hazard ratio [HR], 0.921.081.27; P = 0.3) and ILD grafts (HR, 0.981.161.39, P = 0.09); however, nonpreferred recipients had higher ACGL risk with OLD grafts versus ALD (HR, 1.281.411.56, P < 0.001) and ILD grafts (HR, 1.501.671.86, P < 0.001). Similar trends are seen with mortality. CONCLUSIONS:Because preferred recipients comprise 43.3% (n = 2916) of the current waitlist and span the full range of Model for End-Stage Liver Disease scores, transplanted OLD allografts could be distributed without added risk of graft loss or mortality.

Background:The epidemic of drug overdose deaths in the United States has led to an increase in organ donors. Objective:To characterize donors who died of overdose and to analyze outcomes among transplant recipients. Design:Prospective observational cohort study. Setting:Scientific Registry of Transplant Recipients, 1 January 2000 to 1 September 2017. Participants:138 565 deceased donors; 337 934 transplant recipients at 297 transplant centers. Measurements:The primary exposure was donor mechanism of death (overdose-death donor [ODD], trauma-death donor [TDD], or medical-death donor [MDD]). Patient and graft survival and organ discard (organ recovered but not transplanted) were compared using propensity score-weighted standardized risk differences (sRDs). Results:A total of 7313 ODDs and 19 897 ODD transplants (10 347 kidneys, 5707 livers, 2471 hearts, and 1372 lungs) were identified. Overdose-death donors accounted for 1.1% of donors in 2000 and 13.4% in 2017. They were more likely to be white (85.1%), aged 21 to 40 years (66.3%), infected with hepatitis C virus (HCV) (18.3%), and increased-infectious risk donors (IRDs) (56.4%). Standardized 5-year patient survival was similar for ODD organ recipients compared with TDD organ recipients (sRDs ranged from 3.1% lower to 3.9% higher survival) and MDD organ recipients (sRDs ranged from 2.1% to 5.2% higher survival). Standardized 5-year graft survival was similar between ODD and TDD grafts (minimal difference for kidneys and lungs, marginally lower [sRD, -3.2%] for livers, and marginally higher [sRD, 1.9%] for hearts). Kidney discard was higher for ODDs than TDDs (sRD, 5.2%) or MDDs (sRD, 1.5%); standardization for HCV and IRD status attenuated this difference. Limitation:Inability to distinguish between opioid and nonopioid overdoses. Conclusion:In the United States, transplantation with ODD organs has increased dramatically, with noninferior outcomes in transplant recipients. Concerns about IRD behaviors and hepatitis C among donors lead to excess discard that should be minimized given the current organ shortage. Primary Funding Source:National Institutes of Health.

In the United States, the Centers for Medicare and Medicaid Services (CMS) use Systems Improvement Agreements (SIAs) to require transplant programs repeatedly flagged for poor-performance to improve performance or lose CMS funding for transplants. We identified 14 kidney transplant (KT) programs with SIAs and 28 KT programs without SIAs matched on waitlist volume and characterized kidney acceptance using SRTR data from 12/2006-3/2015. We used difference-in-differences linear regression models to identify changes in acceptance associated with an SIA independent of program variation and trends prior to the SIA. SIA programs accepted 26.9% and 22.1% of offers pre- and post-SIA, while non-SIA programs accepted 33.9% and 44.4% of offers in matched time periods. After adjustment for donor characteristics, time-varying waitlist volume, and secular trends, SIAs were associated with a 5.9 percentage-point (22%) decrease in kidney acceptance (95% CI: -10.9 to -0.8, P = .03). The decrease in acceptance post-SIA was more pronounced for KDPI 0-40 kidneys (12.3 percentage-point decrease, P = .007); reductions in acceptance of higher KDPI kidneys occurred pre-SIA. Programs undergoing SIAs substantially reduced acceptance of kidney offers for waitlisted candidates. Attempts to improve posttransplant outcomes might have the unintended consequence of reducing access to transplantation as programs adopt more restrictive organ selection practices.

BACKGROUND:The rising proportion of older adults in the US population coupled with an increased prevalence of nodular thyroid disease will result in more thyroidectomies being performed. The aim of this study is to evaluate the clinical outcomes among older adults (age ≥65) undergoing thyroidectomy compared to younger adults (18-64). METHODS:This was a population-based study of adult thyroidectomy patients using the Premier Healthcare Database, 2005-2014. Discharge status, hospital length of stay (LOS), morbidity, and total patient charge were compared between younger adults and older adults in three different age groups: ≥65, ≥70, and ≥80 years old. RESULTS:Among 75,141 thyroidectomy patients, 15,805 (21.0%) patients were ≥65 years, 8834 (11.8%) were ≥70 years, and 1613 (2.2%) were ≥80 years. Patients ≥80 years were 2.6 times (aOR:2.58, 95%CI: 1.72-3.86; p < 0.001) more likely to be discharged to a home health organization than to be discharged to their residence and 1.6 times (aOR:1.61, 95%CI: 1.30-2.00; p < 0.001) more likely to have at least one complication. CONCLUSIONS:Age ≥80 is an independent predictor of worse clinical outcomes after thyroidectomy.

BACKGROUND:With passage of the HIV Organ Policy Equity (HOPE) Act, people living with HIV (PLWH) can donate organs to PLWH awaiting transplant. Understanding knowledge and attitudes regarding organ donation among PLWH in the United States is critical to implementing the HOPE Act. METHODS:PLWH were surveyed regarding their knowledge, attitudes, and beliefs about organ donation and transplantation at an urban academic HIV clinic in Baltimore, MD, between August 2016 and October 2016. Responses were compared using Fisher exact and χ tests. RESULTS:Among 114 survey respondents, median age was 55 years, 47.8% were female, and 91.2% were African American. Most were willing to be deceased donors (79.8%) or living donors (62.3%). Most (80.7%) were aware of the US organ shortage; however, only 24.6% knew about the HOPE Act, and only 21.1% were registered donors. Respondents who trusted the medical system or thought their organs would function adequately in recipients were more likely to be willing to be deceased donors (P < 0.001). Respondents who were concerned about surgery, worse health postdonation, or need for changes in HIV treatment because of donation were less likely to be willing to be living donors (P < 0.05 for all). Most believed that PLWH should be permitted to donate (90.4%) and that using HIV+ donor organs for transplant would reduce discrimination against PLWH (72.8%). CONCLUSIONS:Many of the PLWH surveyed expressed willingness to be organ donors. However, knowledge about the HOPE Act and donor registration was low, highlighting a need to increase outreach.