Faculty Bibliography

BACKGROUND:Fewer than 20% of donated lungs are transplanted. We examined the impacts of donor management and recovery at an in-hospital donor care unit (DCU) established in 2021 versus the donor hospital (DH). METHODS:(P/F ratio) were examined as a hypothesized effect modifier. We projected the national impact of improved utilization on lung transplant volume. RESULTS:After adjusting for donor differences, lung utilization was 88% higher (aRR: 1.88; 95% CI: 1.40, 2.53) in the DCU versus DH setting. Median P/F ratio increased from 275 to 348 mmHg (p<0.0001) in the DCU and explained approximately 38% of the improvement in lung utilization. Non-lung organ utilization was either improved or non-inferior in the DCU. Lung graft survival and pulmonary function were similar for recipients of DCU versus DH-managed donors. Nationally, an 88% improvement in lung utilization among donors not currently transferred to a DCU could theoretically result in ≥300 more lung transplants per year. CONCLUSIONS:Lung transplantation can be nearly doubled through lung-centric donor management in a DCU, without sacrificing recipient outcomes nor the utilization of other organs. Donor management practices to optimize lung utilization should be proliferated by establishing more DCUs and, where feasible, applying lung-centric protocols in donor hospitals.

BACKGROUND:The Increasing Organ Transplant Access (IOTA) model is a mandatory experimental payment model that aims to improve kidney transplant access using financial incentives and penalties for transplant centers randomized to model participation, based primarily on growth in transplant volume. METHODS:We used national transplant registry data to conduct a retrospective cohort study of US kidney transplant centers. We identified centers randomized to IOTA participation based on the published list of center participants. Using a difference-in-differences approach, we compared IOTA participants to non-participants on changes in overall, deceased donor, and living donor kidney transplant volume per 30 days in the period before IOTA randomization status was announced versus the 9 months following IOTA implementation. Separately among IOTA participants and among non-participants, we compared the proportional change in transplant volume when stratifying centers by pre-IOTA transplant volume, organ offer acceptance rate, and transplant rate ratio. RESULTS:Among 177 included centers, 97 (55%) were IOTA participants and 80 (45%) non-participants. Most IOTA participants (53%) and non-participants (55%) experienced a fall in overall transplant volume after model implementation. However, IOTA participants exhibited a 5% increase in transplant volume per 30 days, whereas non-participants exhibited a 3% decrease (P=0.01). The difference between groups was seen for deceased donor transplants (participants +5% vs. non-participants -9%, P<0.001), while living donor transplants rose in both groups (+7 vs. +19%, P=0.24). Among IOTA participants, there were no statistically significant differences in changes in transplant volume when comparing centers categorized by pre-IOTA transplant volume, organ offer acceptance rate, or transplant rate ratio. CONCLUSIONS:Centers randomized to IOTA participation outperformed model non-participants in changes in kidney transplant volume after model implementation, driven by an increase in deceased donor transplant volume among model participants but a fall among non-participants.

Kidneys from donation after circulatory death (DCD) donors historically had lower recovery and utilization than kidneys from donation after brain death (DBD) donors. However, the organ shortage and advances in organ preservation have increased interest in DCD transplantation. We used OPTN data to study temporal changes in U.S. DCD kidney recovery and transplantation. The percent DCD among kidney donors increased from 21.0% (Era1: 2016-2019) to 30.6% (Era2: 2020-2022) and 42.4% (Era3: 2023-2025). By 2025Q2, more than half (50.4%) of kidney donors were DCDs. Wide variability persisted across eras in percent DCD by recovering OPO (Era1 range: 0%-38%, Era2: 0%-49%, Era3: 0.4%-60%) and by transplanting center (Era1 range: 0%-48%, Era2: 0%-58%, Era3: 0%-60%). Transplanted DCD kidneys in Era3 (vs Era1 & Era2) were more likely to have donor age >60, diabetes, hypertension, obesity, and death due to cardiovascular disease or stroke; 86.8% were pumped. Though the recovered DCD kidney nonuse rate rose from 20.8% (Era1) to 29.9% (Era2) and 35.4% (Era3), nonused DCD kidney donors were age and had more comorbidities in Era 3 compared to earlier eras. Given that half of kidney donors are now DCD, refinements in DCD donor selection and management are needed to optimize recovery and utilization.

Disparities in deceased donor liver transplantation (DDLT) may be due to geographic imbalances of organ supply-to-demand ratios and/or center organ acceptance practices. We evaluated the relative contribution of centers versus broader geographic units (DSAs/States/OPTN regions/census divisions) to variability of DDLT rate. Using SRTR data on adult, first-time, non-Status1A, period-prevalent waitlist candidates, we conducted multilevel Poisson regression with center-level and donor service area (DSA)-level intercepts to model DDLT rates across three eras: pre-acuity circles (AC)(5/1/2017-4/30/2019), initial post-AC (2/4/2020-2/3/2022), and recent post-AC (02/04/2022-12/31/2024), adjusting for candidate factors. We calculated center-level and DSA-level median incidence rate ratios (MIRRs) and their relative contributions to total geographic variation. DSA-level MIRR declined from _1.471.52_1.58 to _1.321.37_1.42 to _1.171.23_1.28 from pre-AC to initial post-AC to recent post-AC. The center-level, within-DSA MIRR increased from _1.561.61_1.64 to _1.761.82_1.84 to _1.921.96_2.05 across eras. The DSA-level contribution to total center-level variation declined from 43.7% to 21.5% to 8.4% across eras. Similarly, the contribution of other broad, geographic units (States/OPTN regions/census divisions) to total geographic variation in DDLT rates decreased after AC. Further allocation changes are unlikely to substantially reduce geographic disparities because DDLT rate variation is predominantly driven by center-level differences, which were associated with highly variable advanced preservation practices.

As hepatitis C virus (HCV) infection is now curable, HCV-positive donor organs have expanded the deceased donor pool. Using OPTN data, we identified adult kidney, liver, heart, and lung candidates listed between 2016-2025 and evaluated rates of consent to accept HCV antibody-positive (Ab+) and HCV viremic (NAT+) organs. Temporal trends were described, and multilevel modified Poisson regression with center-level random effects was used to estimate adjusted risk ratios for candidate factors and quantify center variation using median incidence rate ratios (MIRR). Rates of consent to accept both HCV Ab+ and NAT+ organs rose over time. By the end of follow-up, consent rates for HCV Ab+ organs were 63.1% for kidney, 80.6% for liver, 73.3% for heart, and 72.1% for lung candidates, and consent rates for NAT+ organs were 44.9%, 70.7%, 50.5%, and 46.1%, respectively. Associations between candidate characteristics and consent were small after adjustment for center, whereas center effects were large. For HCV Ab+ organs, MIRRs were 6.31 (kidney), 2.48 (liver), 2.90 (heart), and 4.36 (lung); for NAT+ organs, MIRRs were even higher, 9.65, 3.19, 4.00, and 7.30, respectively, indicating marked between-center variability. Our analyses suggest that access to HCV-positive organs is influenced more by center practices than patient characteristics.

INTRODUCTION/BACKGROUND:Biological parental donations provide the best option for many pediatric recipients, yielding unique immunological benefits that may enable minimization of immunosuppression in transplanted children. However, living related maternal donation in the postpartum period may introduce an increased risk of donor complications due to the physiological changes of pregnancy and childbirth, and the optimal timing of postpartum living donation is unknown. METHODS:Using US national registry data, we characterized donor and recipient outcomes for pediatric living donor liver transplants performed between 2004 and 2022 where a biological mother donated to a child ≤ 24 months old. RESULTS:Our study population included 256 donor-recipient pairs, with biliary atresia representing the most common indication for transplantation (68.0%). Donors had a median [IQR] age of 30 [25, 34] years, and the median [IQR] time from birth to donation was 9.0 [6.8, 13.0] months. 6.3% of donors experienced a biliary or other complication. When stratifying by donors who donated ≤ 6 vs. > 6 months postpartum, we found no significant differences in donor complications or readmission. Stratified analyses were also comparable for recipient mortality, graft survival, and rejection-free survival. Donors ≤ 6 months postpartum (n = 64) were more likely to experience reoperation than mothers who donated > 6 months postpartum (n = 192) (6.2% vs. 1.0%, p = 0.04). CONCLUSIONS:While maternal living donor liver transplantation is safe for most donors, there is a higher risk of reoperation when donation is performed ≤ 6 months postpartum. Surgeons should be aware that these donors are a higher risk population, requiring discussion upon consent and warranting close post-operative monitoring.

BACKGROUND:Portomesenteric venous thrombosis (PMVT) is a rare complication of bariatric surgery that can lead to cavernous transformation of the portal vein. There are no established treatment algorithms regarding anticoagulation (AC) only vs. catheter-directed thrombolysis in this population. METHODS:Medical records at 4 urban bariatric surgery centers were queried for patients diagnosed with PMVT between 2012 and 2025. Patient characteristics, perioperative details, imaging at PMVT diagnosis, treatment course, and follow-up imaging were reviewed. Fisher's exact testing was conducted to identify correlations between extent of thrombosis, treatment course (anticoagulation vs. interventional radiology [IR] thrombolysis), and the outcome of cavernous transformation. RESULTS:71 patients were diagnosed with PMVT following bariatric surgery (68 LSG, 3 RYGB) at 4 centers between 2012 and 2025. Median time from surgery to PMVT diagnosis was 13 days. Three patients (4%) required reoperation for small bowel resection, of whom 2 underwent open thrombectomy and 1 underwent subsequent IR thrombolysis. Of the remaining patients, 6/68 (9%) underwent IR catheter-directed thrombolysis, and 62/68 (91%) received AC only. Of 53 patients with long-term data, 18 (34%) developed cavernous transformation. Among patients who had a main portal vein + intrahepatic portal vein + inflow (superior mesenteric vein or splenic vein) thrombosis, treatment with AC only was strongly associated with cavernous transformation (13/17, 76%) vs IR (1/5, 20%, p < 0.05). There were no deaths related to PMVT. CONCLUSIONS:In this largest known case series of postbariatric surgery PMVT treated with anticoagulation vs. IR, we found that the PMVT clot pattern with the highest risk of developing cavernous transformation was the extensive type involving the main portal vein, an intrahepatic portal vein, and an inflow vein, whether the main portal vein clot was occlusive or nonocclusive. Early IR intervention was associated with decreased cavernous transformation.

BACKGROUND:As a 6-month waiting period is required to receive exception points to prioritize patients with hepatocellular carcinoma (HCC) for liver transplantation, prompt addition to the waitlist is critical in access to LT. METHODS:Using Epic Cosmos data on patients with HCC referred for LT 1/2018-10/2024, we used modified Poisson regression to calculate rates of waitlisting. Center-level and individual (socioeconomic, geographic, and insurance) factors were measured among those who progressed. RESULTS:Among 11,422 HCC patients referred for LT at 70 centers, with median age 63 [IQR: 58, 68], 71.5% initiated evaluation and, of those who began evaluation, 57.6% were waitlisted for LT. Of those referred, patients who were older (age 70+ vs. 51-60; RR 0.77, 95% CI: 0.65-0.90, p < 0.001), on Medicaid (0.83, 95% CI: 0.71-0.97, p = 0.02), never-married (0.82, 95% CI: 0.73-0.91, p < 0.001), or low SES (Q4: 0.87, 95% CI: 0.77-0.97, p = 0.002) had lower rates of waitlisting. Among waitlisted patients, median time from referral was 3.3 months [IQR: 2.0, 5.3]. Despite adjustment for patient level covariates, there was high center-level variation in rate of waitlisting within 12 months; 13% of centers listed patients at a rate ≥ 20% below the national median. CONCLUSION/CONCLUSIONS:Only a fraction of referred patients with HCC are waitlisted for LT. High variation in access to waitlisting based on non-clinical factors suggests barriers to waitlisting that must be addressed. Centers should focus on interventions to reduce barriers to waitlisting in patients with HCC.