Faculty Bibliography

IMPORTANCE/UNASSIGNED:Neighborhood segregation, a mechanism of structural racism, is associated with racial and ethnic disparities in health care access and outcomes. Live donor liver transplant (LDLT) is the ideal treatment for cirrhosis, improving survival and quality of life. Understanding the role of segregation in LDLT access is important to address disparities. OBJECTIVE/UNASSIGNED:To assess the associations between residential and transplant center neighborhood segregation and LDLT access. DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:This cohort study used data from a US national transplant registry on adult candidates (age ≥18 years) for first-time liver transplant between February 1, 2016, and June 30, 2025, at centers that performed 1 or more LDLT annually during that time. EXPOSURE/UNASSIGNED:Residential and transplant center neighborhood segregation, measured using the Thiel H method at the zip code tabulation area level and dichotomized at the respective median values. MAIN OUTCOMES AND MEASURES/UNASSIGNED:A Cox proportional hazards regression model quantified the adjusted hazard ratio (AHR) of LDLT and included interactions with race and ethnicity and insurance. LDLT access within high-segregation residential neighborhoods by racial and ethnic composition (predominantly White or predominantly racial and ethnic minoritized population) was also quantified. RESULTS/UNASSIGNED:Among 22 223 adult liver transplant candidates, mean (SD) age was 55.3 (11.2) years, 13 518 (60.8%) were male, 1476 (6.6%) were Black, 5097 (22.9%) were Hispanic or Latino, and 15 650 (70.4%) were White. Most (11 669 [52.5%]) had private insurance. After adjustment, candidates residing in high-segregation neighborhoods had lower likelihood of LDLT access (AHR, 0.81; 95% CI, 0.74-0.88). Hispanic or Latino candidates in high-segregation neighborhoods had lower likelihood of LDLT access than their counterparts in low-segregation neighborhoods (AHR, 0.59; 95% CI, 0.49-0.72; P < .001 for interaction), but associations between neighborhood segregation and LDLT did not vary significantly by insurance type (P = .52 for interaction). Candidates wait-listed at transplant centers in high-segregation neighborhoods had lower likelihood of LDLT access (AHR, 0.64; 95% CI, 0.59-0.70). Candidates with Medicare or Medicaid wait-listed at centers in high-segregation neighborhoods had lower likelihood of LDLT access than their counterparts in low-segregation neighborhoods (AHR, 0.53; 95% CI, 0.45-0.51; P < .001 for interaction). Within high-segregation residential neighborhoods, candidates in neighborhoods with a larger racial and ethnic population had lower likelihood of LDLT access than those living in neighborhoods with a larger White population (AHR, 0.68; 95% CI, 0.59-0.78). CONCLUSION AND RELEVANCE/UNASSIGNED:In this national cohort study, living in or being wait-listed at centers in high-segregation neighborhoods was associated with lower likelihood of LDLT access and candidates living in high-segregation neighborhoods with a larger racial and ethnic minority population compared with a larger White population had lower likelihood of LDLT. Investing in high-segregation neighborhoods to address these structural disadvantages may help improve equity in LDLT access.

BACKGROUND:Robotic pancreaticoduodenectomy (RPD) is increasingly performed in the United States. Understanding factors associated with safe adoption of RPD is critical to reducing perioperative mortality during the learning curve. METHODS:Using the Epic Cosmos database, the study identified adult patients (age ≥18 years) who underwent pancreaticoduodenectomy (PD) between 2019 and 2025. Modified Poisson regression was used to assess factors associated with 30-day mortality using adjustment for age, sex, race, ethnicity, insurance, marital status, rural/urban residence, socioeconomic status, and diagnosis. Among surgeons performing two or more RPDs, mortality trends were analyzed across case-number thresholds. Mortality risk was assessed by cumulative RPD and open PD (OPD) experience, with adjustment for age and diagnosis. RESULTS:Among 23,995 patients with a median age of 69 years (interquartile range [IQR], 62-75 years), 1578 (6.6 %) underwent RPD. Use of RPD increased from 4% of PD in 2019 to 10% in 2025. The 30-day mortality was higher for RPD than for OPD (2.7 % vs 2.0 %; adjusted relative risks [aRR], 1.43 (IQR, 1.02-1.95; p = 0.029). In RPD, mortality decreased with increasing surgeon prior experience: 3.9 % (Q1: 0-1 cases), 3.9 % (Q2: 2-4 cases), 2.22 % (Q3: 5-8 cases), 2.67 % (Q4: 9-18 cases), 0.92 % (Q5: 19-71 cases). Increased RPD experience was associated with decreased mortality (per doubling RPD experience: aRR, 0.78 (95 % confidence interval [CI], 0.63-0.96; p = 0.02). The patients who underwent PD between 2023 and 2025 showed no adjusted increase in mortality with robotic technique (aRR, 1.04; 95 % CI, 0.61-1.65; p = 0.85). CONCLUSIONS:Nationwide, adoption of RPD is associated with increased 30-day mortality, which decreases substantially with increasing surgeon RPD experience. These findings suggest that structured, competency-based training pathways are needed to ensure safe dissemination of novel technology, including RPD.

OBJECTIVE/UNASSIGNED:To perform comprehensive validations of the integrative Box (iBox) system, a prediction model for long term risk of kidney allograft failure, for extension of its context of use in clinical trials as well as for its wider implementation in clinical practice. DESIGN/UNASSIGNED:Extended validation study. SETTING/UNASSIGNED:Paris Transplant Group database (comprising kidney recipients with transplantations between 1 January 2005 and 1 January 2014) and European, North American, and South American hospitals (comprising recipients of kidneys transplanted beween 1 January 2000 and 1 January 2022). Patients were followed until 1 November 2024. PARTICIPANTS/UNASSIGNED:12 683 kidney tranplant recipients from 21 academic centres in Europe, North America, and South America; 4000 patients in the derivation cohort and 8683 in the validation cohorts. MAIN OUTCOME MEASURES/UNASSIGNED:Performance of the iBox, including flexible iBox versions in specific clinical contexts (race-free estimated glomerular filtration rate (eGFR) equations (ie, without including race as a factor in the calculation), in specific clinical contexts (initial nephropathy recurrence, BK virus associated nephropathy, and different immunosuppressive strategies), and over-extended follow-up periods. Predictive performance was assessed by discrimination, calibration, overall fit, and clinical utility. RESULTS/UNASSIGNED:0.57) in its predictive ability. CONCLUSIONS/UNASSIGNED:In this study, the robust predictive performance of the iBox system across diverse real world settings and clinical scenarios was shown. These results highlight the versatility and reliability of the iBox system, and support its use for risk stratification in routine clinical practice and as a surrogate endpoint for clinical trials.

INTRODUCTION/BACKGROUND:Hyperparathyroidism (HPT) commonly persists following kidney transplant (KT) and can result in bone alterations. However, the association between persistent HPT post-KT and fracture risk is not well-understood. We sought to quantify the association between persistent HPT at 1-year post-KT and fracture risk among KT recipients. METHODS:We leveraged a longitudinal prospective cohort of 344 adult KT recipients who underwent KT at a single institution (12/2008-07/2019). PTH levels were retroactively abstracted, and fractures after 1-year-post-KT were ascertained using ICD-9/ICD-10 codes. Competing risk models were used to estimate the association between persistent HPT (PTH ≥ 70 pg/mL) at 1-year post-KT and the risk of fracture, with death treated as a competing event. RESULTS:Among 344 KT recipients, 227 (66.0%) had persistent HPT at 1-year post-KT. After adjusting for confounders, HPT 1-year after KT was associated with a 3.11-fold increased risk of fractures (95% CI: 1.08-8.91). There were no differences in this association by age, sex, race, eGFR at 1-year-post-KT, osteoporosis at KT, or dialysis vintage. CONCLUSION/CONCLUSIONS:Recipients with HPT 1-year after KT had a significantly higher risk of fractures than those without persistent HPT. Future studies should establish standardized practice guidelines for the treatment of persistent HPT to mitigate fracture-related morbidity and mortality.

Pediatric deceased donor kidneys with acute kidney injury (ped-AKI) are at increased risk for non-utilization. To evaluate the post-transplant outcomes of ped-AKI recipients, we conducted a retrospective cohort study, comparing 17,731 adult recipients of kidneys from pediatric donors without AKI (ped-non-AKI, terminal serum creatinine (SCr)<1 mg/dL) to 1,589 ped-AKI recipients (SCr≥2 mg/dL). We used weighted logistic regression to estimate the association between ped-AKI and delayed graft function (DGF), and weighted Cox regression to estimate the association between ped-AKI and primary non-function (PNF) and all-cause graft failure (ACGF). Ped-AKI kidney recipients were at 6.0-fold (aOR=_5.325.98_6.72), 1.9-fold (aHR=_1.361.87_2.58), and 1.4-fold (aHR=_1.161.43_1.76) higher risk of DGF, PNF, and 1-year ACGF compared to ped-non-AKI recipients. En bloc ped-AKI recipients were at 5.6-fold (aOR=_3.295.57_9.43), 3.3-fold (aHR=_1.723.25_6.15), and 2.9-fold (aHR=_1.702.92_5.01) higher risk of DGF, PNF, 1-year ACGF compared to en bloc ped-non-AKI recipients. Among recipients of single kidneys from donors<20kg, ped-AKI recipients were at 8.9-fold (aOR=_4.348.87_18.12), 5-fold (aHR=_1.694.99_14.75), and 3.4-fold (aHR=_1.473.44_8.05) higher risk of DGF, PNF, 1-year ACGF compared to ped-non-AKI recipients. Ped-AKI kidney recipients have higher risks of early graft complications and failure. Risks are greatest for recipients of single kidneys from donors<20kg. Careful recipient selection and counseling are prudent when considering ped-AKI kidney offers.

BACKGROUND:Before KAS250 (circles-based allocation), donor service area (DSA) of listing was the largest contributor to deceased donor kidney transplantation (DDKT) rate disparities. Both before and after KAS250, it is unclear to what extent DSA-level disparities are attributable to center-level practice variation. We aimed to disentangle contributions to DDKT rate variation from: (1) center practices, (2) kidney distribution within sharp policy boundaries (DSAs, OPTN Regions), and (3) other geographic variation in kidney scarcity. METHODS:With national transplant registry data, we studied transplant rate variation in the pre-KAS250 era, which prioritized patients based on DSAs and Regions, and under KAS250, which prioritizes patients within 250 nautical mile circles. We modeled candidate DDKT rates with multilevel Poisson regression, adjusting for candidate factors, and calculated median incidence rate ratios (MIRR) to summarize variation attributable to DSAs, OPTN regions, states, census divisions, and to centers within those units. RESULTS:). Adjusted center-level DDKT rates under KAS250 were highly associated with offer acceptance rates (ρ = 0.60, p < 0.001). CONCLUSIONS:Though geographic disparities are driven primarily by center-level practice differences including offer acceptance, KAS250 did reduce DSA-level disparities. Further allocation policy changes are unlikely to substantially reduce geographic variation in DDKT rates.