Faculty Bibliography

BACKGROUND:Transplant recipients are living longer than ever before, and occasionally require acute care surgery for nontransplant-related issues. We hypothesized that while both acute care surgeons (ACS) and transplant surgeons would feel comfortable operating on this unique patient population, both would believe transplant centers provide superior care. METHODS:, Fisher's exact, and Kruskal-Wallis tests. RESULTS:We obtained 230 responses from ACS and 204 from transplant surgeons. ACS and transplant surgeons believed care is better at transplant centers (78% and 100%), and transplant recipients requiring acute care surgery should be transferred to a transplant center (80.2% and 87.2%). ACS felt comfortable operating (97.5%) and performing laparoscopy (94.0%) on transplant recipients. ACS cited transplant medication use as the most important underlying cause of increased surgical complications for transplant recipients. Transplant surgeons felt it was their responsibility to perform acute care surgery on transplant recipients (67.3%), but less so if patient underwent transplant at a different institution (26.5%). Transplant surgeons cited poor transplanted organ resiliency as the most important underlying cause of increased surgical complications for transplant recipients. CONCLUSIONS:ACS and transplant surgeons feel comfortable performing laparoscopic and open acute care surgery on transplant recipients, and recommend treating transplant recipients at transplant centers, despite the lack of supportive evidence. Elucidating common goals allows surgeons to provide optimal care for this unique patient population.

Using nonideal kidneys for transplant quickly might reduce the discard rate of kidney transplants. We studied changing kidney allocation to eliminate sequential offers, instead making offers to multiple centers for all nonlocally allocated kidneys, so that multiple centers must accept or decline within the same 1 hour. If more than 1 center accepted an offer, the kidney would go to the highest-priority accepting candidate. Using 2010 Kidney-Pancreas Simulated Allocation Model-Scientific Registry for Transplant Recipients data, we simulated the allocation of 12 933 kidneys, excluding locally allocated and zero-mismatch kidneys. We assumed that each hour of delay decreased the probability of acceptance by 5% and that kidneys would be discarded after 20 hours of offers beyond the local level. We simulated offering kidneys simultaneously to small, medium-size, and large batches of centers. Increasing the batch size increased the percentage of kidneys accepted and shortened allocation times. Going from small to large batches increased the number of kidneys accepted from 10 085 (92%) to 10 802 (98%) for low-Kidney Donor Risk Index kidneys and from 1257 (65%) to 1737 (89%) for high-Kidney Donor Risk Index kidneys. The average number of offers that a center received each week was 10.1 for small batches and 16.8 for large batches. Simultaneously expiring offers might allow faster allocation and decrease the number of discards, while still maintaining an acceptable screening burden.

The Kidney Allocation System (KAS) has resulted in fewer pediatric kidneys being allocated to pediatric deceased donor kidney transplant (pDDKT) recipients. This had prompted concerns that post-pDDKT outcomes may worsen. To study this, we used SRTR data to compare the outcomes of 953 pre-KAS pDDKT (age <18 years) recipients (December 4, 2012-December 3, 2014) with the outcomes of 934 post-KAS pDDKT recipients (December 4, 2014-December 3, 2016). We analyzed mortality and graft loss by using Cox regression, delayed graft function (DGF) by using logistic regression, and length of stay (LOS) by using negative binomial regression. Post-KAS recipients had longer pretransplant dialysis times (median 1.26 vs 1.07 years, P = .02) and were more often cPRA 100% (2.0% vs 0.1%, P = .001). Post-KAS recipients had less graft loss than pre-KAS recipients (hazard ratio [HR]: _0.35 0.54_0.83 , P = .005) but no statistically significant differences in mortality (HR: _0.29 0.72_1.83 , P = .5), DGF (odds ratio: _0.93 1.32_1.93 , P = .2), and LOS (LOS ratio: _0.96 1.06_1.19 , P = .4). After adjusting for donor-recipient characteristics, there were no statistically significant post-KAS differences in mortality (adjusted HR: _0.37 1.04_2.92 , P = .9), DGF (adjusted odds ratio: _0.94 1.41_2.13 , P = .1), or LOS (adjusted LOS ratio: _0.93 1.04_1.16 , P = .5). However, post-KAS pDDKT recipients still had less graft loss (adjusted HR: _0.38 0.59_0.91 , P = .02). KAS has had a mixed effect on short-term posttransplant outcomes for pDDKT recipients, although our results are limited by only 2 years of posttransplant follow-up.

BACKGROUND AND OBJECTIVES:The risk of hypertension attributable to living kidney donation remains unknown as does the effect of developing postdonation hypertension on subsequent eGFR. We sought to understand the association between living kidney donation, hypertension, and long-term eGFR by comparing donors with a cohort of healthy nondonors. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS:We compared 1295 living kidney donors with median 6 years of follow-up with a weighted cohort of 8233 healthy nondonors. We quantified the risk of self-reported hypertension using a parametric survival model. We examined the association of hypertension with yearly change in eGFR using multilevel linear regression and clustering by participant, with an interaction term for race. RESULTS:=0.01, respectively, after hypertension). CONCLUSIONS:Kidney donors are at higher risk of hypertension than similar healthy nondonors, regardless of race. Donors who developed hypertension had a plateau in the usual postdonation increase of eGFR.

BACKGROUND:Despite providing survival benefit, increased risk for infectious disease (IRD) kidney offers are declined at 1.5 times the rate of non-IRD kidneys. Elucidating sources of variation in IRD kidney offer acceptance may highlight opportunities to expand use of these life-saving organs. METHODS:To explore center-level variation in offer acceptance, we studied 6765 transplanted IRD kidneys offered to 187 transplant centers between 2009 and 2017 using Scientific Registry of Transplant Recipients data. We used multilevel logistic regression to determine characteristics associated with offer acceptance and to calculate the median odds ratio (MOR) of acceptance (higher MOR indicates greater heterogeneity). RESULTS:Higher quality kidneys (per 10 units kidney donor profile index; adjusted odds ratio [aOR], 0.94; 95% confidence interval [CI], 0.92-0.95), higher yearly volume (per 10 deceased donor kidney transplants; aOR, 1.08, 95% CI, 1.06-1.10), smaller waitlist size (per 100 candidates; aOR, 0.97; 95% CI, 0.95-0.98), and fewer transplant centers in the donor service area (per center; aOR, 0.88; 95% CI, 0.85-0.91) were associated with greater odds of IRD acceptance. Adjusting for donor and center characteristics, we found wide heterogeneity in IRD offer acceptance (MOR, 1.96). In other words, if listed at a center with more aggressive acceptance practices, a candidate could be 2 times more likely to have an IRD kidney offer accepted. CONCLUSIONS:Wide national variation in IRD kidney offer acceptance limits access to life-saving kidneys for many transplant candidates.

The Johns Hopkins University School of Medicine organized 2 multistakeholder symposia on February 2, 2018 and January 11, 2019 to address the problem of high graft failure in adolescent and young adult (AYA) solid organ transplant (SOT) recipients. Participants included international experts in transplantation, behavioral psychology, patient/parent advocacy, and technology. The objectives of the symposia were as follows: (1) to identify and discuss the barriers to and facilitators of effective transfer of care for AYA SOT recipients; (2) to actively explore strategies and digital solutions to promote their successful transfer of care; and (3) to develop meaningful partnerships for the successful development, evaluation, implementation, and dissemination of these digital solutions. Additionally, data were collected from 152 AYA SOT recipients demonstrating a substantial gap in how this population uses technologies for health-related activities, alongside an increased interest in an app to help them manage their transplant.

Pediatric kidney transplant candidates often have multiple potential living donors (LDs); no evidence-based tool exists to compare potential LDs, or to decide between marginal LDs and deceased donor (DD) kidney transplantation (KT). We developed a pediatric living kidney donor profile index (P-LKDPI) on the same scale as the DD KDPI by using Cox regression to model the risk of all-cause graft loss as a function of living donor characteristics and DD KDPI. HLA-B mismatch (adjusted hazard ratio [aHR] per mismatch = _1.04 1.27_1.55 ), HLA-DR mismatch (aHR per mismatch = _1.02 1.23_1.49 ), ABO incompatibility (aHR = _1.20 3.26_8.81 ), donor systolic blood pressure (aHR per 10 mm Hg = _1.01 1.07_1.18 ), and donor estimated GFR (eGFR; aHR per 10 mL/min/1.73 m² = _0.88 0.94_0.99 ) were associated with graft loss after LDKT. Median (interquartile range [IQR]) P-LKDPI was -25 (-56 to 12). 68% of donors had P-LKDPI <0 (less risk than any DD kidney) and 25% of donors had P-LKDPI >14 (more risk than median DD kidney among pediatric KT recipients during the study period). Strata of LDKT recipients of kidneys with higher P-LKDPI had a higher cumulative incidence of graft loss (39% at 10 years for P-LDKPI ≥20, 28% for 20> P-LKDPI ≥-20, 23% for -20 > P-LKDPI ≥-60, 19% for P-LKDPI <-60 [log rank P < .001]). The P-LKDPI can aid in organ selection for pediatric KT recipients by allowing comparison of potential LD and DD kidneys.

We examined a novel linkage of national US donor registry data with records from a pharmacy claims warehouse (2007-2016) to examine associations (adjusted hazard ratio, _LCL aHR_UCL ) of post-donation fills of antidiabetic medications (ADM, insulin or non-insulin agents) with body mass index (BMI) at donation and other demographic and clinical factors. In 28 515 living kidney donors (LKDs), incidence of ADM use at 9 years rose in a graded manner with higher baseline BMI: underweight, 0.9%; normal weight, 2.1%; overweight, 3.5%; obese, 8.5%. Obesity was associated with higher risk of ADM use compared with normal BMI (aHR, _3.36 4.59_6.27 ). Metformin was the most commonly used ADM and was filled more often by obese than by normal weight donors (9-year incidence, 6.87% vs 1.85%, aHR, _3.55 5.00_7.04 ). Insulin use was uncommon and did not differ significantly by BMI. Among a subgroup with BMI data at the 1-year post-donation anniversary (n = 19 528), compared with stable BMI, BMI increase >0.5 kg/m² by year 1 was associated with increased risk of subsequent ADM use (aHR, _1.03 1.48_2.14, P = .04). While this study did not assess the impact of donation on the development of obesity, these data support that among LKD, obesity is a strong correlate of ADM use.