Faculty Bibliography

Procurement biopsies are routinely obtained in the United States to evaluate kidneys considered for transplantation, but some argue that they may contribute to kidney nonutilization. Historically, biopsy decisions have been left solely to the discretion of organ procurement organizations (OPOs) and transplant centers. In September 2022, an organ procurement and transplantation network (OPTN) policy designating donors meeting specific clinical criteria as "biopsy-required" went into effect. Using OPTN data from 1 year before and after policy implementation, we used causal inference methods to estimate the policy's impacts on biopsy practices and kidney utilization. The overall biopsy rate remained stable at 62%, rising from 90.6% to 95.8% (P < .001) among biopsy-required kidneys while falling from 49.1% to 43.4% (P < .001) among biopsy-optional kidneys. After adjusting for changing donor characteristics, the policy was associated with a 5% decline in the biopsy rate (adjusted risk ratio = 0.95; P = .007). The overall kidney nonuse rate rose from 27.2% to 28.7%. After accounting for changes in donor characteristics, the policy was not associated with elevated nonuse (adjusted risk ratio = 0.96, P = .06). Although most OPOs are now biopsying nearly all required kidneys, practices still vary widely regarding biopsy-optional kidneys. No correlation was found between OPO-level changes in adjusted biopsy and nonuse rates (ρ = 0.05, P = .70). The OPTN policy has partially standardized biopsy practices without harming kidney utilization.

BACKGROUND:Under the HOPE Act, transplants from donors with HIV to recipients with HIV (HIV D+/R+) have been largely limited to kidney and liver. However, recent modifications to HOPE research guidelines allow broader participation of cardiothoracic programs. METHODS:To quantify potential cardiothoracic HOPE donors, we used SRTR data (3/2016-12/2024) to identify 101,200 donors without HIV and 273 HOPE donors (with true and false positive HIV tests). Using logistic regression, we predicted the probability of having a heart or lung(s) used for transplant among donors without HIV that had a kidney or liver used. We then applied model parameters to HOPE donors that had a kidney or liver used to estimate the number of HOPE donors that might have been cardiothoracic donors if the practice were expanded. RESULTS:Among donors without HIV, cardiothoracic donation was associated with age, cause of death, hepatitis C, hypertension, diabetes, smoking, cardiovascular disease, blood gas, and circulatory death. Applying our model, an estimated 41.0% (N=111), 18.7% (N=51), and 15.2% (N=41) of HOPE donors were potential heart, any lung (single or double), or double-lung donors, as compared to 32.3%, 21.8%, and 18.2% of abdominal organ donors without HIV, respectively. This translated to an annual 13-18 potential heart and 5-8 potential lung transplants (of which 4-6 would be double-lung transplants) from HOPE donors. CONCLUSIONS:If HIV D+/R+ is more widely expanded to cardiothoracic transplantation, 41% of HOPE kidney and liver donors have potential to donate a heart and almost 20% to donate a lung to candidates with HIV.

With U.S. Food and Drug Administration (FDA) clearance of clinical trials of kidney xenotransplantation (XTx) in living humans, understanding the recipient experience is critical. Semi-structured interviews with the three living XTx recipients identified core domains of the recipient experience, including quality of life (QoL), fears about XTx, and healthcare team communication and support. Transcribed interviews were analyzed by two qualitative researchers using an inductive thematic approach and were mapped onto the Warwick Patient Experience Model, a validated framework to assess key aspects of patient satisfaction with the healthcare experience. All three recipients (53-year-old female; 66-year-old male; 54-year old male) described a restoration of hope, contrasted with their poor quality of life on dialysis. They emphasized that access to XTx and graft survival requires mutual confidence and commitment between recipients and healthcare teams. XTx recipients use dialysis as a point of reference when describing changes in their post-transplant QoL and seemed well-situated to handle the possibility of graft failure. These insights may aid in the creation of decision aids and educational materials tailored to the specific needs of XTx recipients.

BACKGROUND:To encourage high-quality, reduced-cost care for total joint arthroplasty (TJA), the Centers of Medicare & Medicaid Services mandated a pay-for-performance model, the Comprehensive Care for Joint Replacement (CJR), as part of the Patient Protection and Affordable Care Act (PPACA). The CJR incentivizes cost containment, and it was anticipated that its implementation would reduce access to TJA for high-cost populations. Patients with end-stage kidney disease (ESKD) undergoing kidney replacement therapy (dialysis and kidney transplant) are costly compared with healthier patients, but it was unknown whether this population lost access to hip and knee replacement because of CJR implementation. This population allows study of whether TJA is accessible for medically complex patients whose risk of surgical complications has been mitigated, as kidney transplantation improves outcomes compared with dialysis, allowing evaluation as to whether access improved when patients crossed over from dialysis to transplantation. Because all patients with ESKD are included in a mandated national registry, we can quantify whether access changed for patients who underwent dialysis and transplantation. QUESTIONS/PURPOSES/OBJECTIVE:(1) How did the rate of TJA change amid the shift to bundled payments for patients with ESKD receiving dialysis? (2) How did the rate of TJA change amid the shift to bundled payments for patients with ESKD after kidney transplant? METHODS:This was an observational cohort study from 2008 to 2018 using the United States Renal Data System, a mandatory national registry that allows for the opportunity to study all individuals with ESKD. During the study period, we identified 1,324,614 adults undergoing routine dialysis and 187,212 adult kidney transplant recipients; after exclusion for non-Medicare primary insurance (n = 785,224 for dialysis and 78,011 for transplant), patients who were 100 years or older (n = 79 and 0, respectively), those who resided outside of 50 US states and Puerto Rico (n = 781 and 87, respectively), missing dialysis status for the dialysis cohort (n = 8658), and multiorgan transplant recipients for the transplant cohort (n = 2442), our study population was 40% (529,872) of patients who underwent routine dialysis and 57% (106,672) of adult kidney transplant recipients, respectively. TJA was ascertained using Medicare Severity Diagnosis Related Groups and ICD-9 and ICD-10 codes. We divided the study period by PPACA (January 1, 2014, to March 31, 2016) and CJR (April 1, 2016, to December 31, 2018) implementation and compared the incidence of TJA by era using mixed-effects Poisson regression adjusting for calendar time and clinical and demographic variables. RESULTS:After adjustment for linear temporal trend and patient case mix, there was no evidence of association between policy implementation and the incidence of TJA. In the dialysis cohort, the adjusted incidence rate ratio (IRR) for TJA was 1.06 (95% confidence interval [CI] 0.98 to 1.14; p = 0.2) comparing PPACA with the previous period and 1.02 (95% CI 0.96 to 1.08; p = 0.6) comparing CJR with the previous periods. Similarly, in the transplant cohort, the adjusted IRR for TJA was 0.82 (95% CI 0.67 to 1.02; p = 0.07) comparing PPACA with the previous period and 1.10 (95% CI 0.94 to 1.28; p = 0.9) comparing CJR with the previous periods. CONCLUSION/CONCLUSIONS:There was no loss in access to TJA for medically complex patients receiving kidney replacement therapy. The increase in TJA incidence for patients after kidney transplant and decrease for patients receiving dialysis suggest that surgeons continued to provide care for higher risk patients whose risk of morbidity or mortality with total joint replacement has been maximally improved after transplantation. LEVEL OF EVIDENCE/METHODS:Level III, prognostic study.

The benefits of bilateral lung transplantation (BLT) versus single lung transplantation (SLT) are still debated. One impediment to clinical recommendations is that BLT vs. SLT advantages may vary based on underlying disease. Since both options are clinically tenable in patients with emphysema, we conducted a comprehensive assessment of lung allograft survival in this population. Using U.S. registry data, we studied time to all-cause allograft failure in 8,092 patients 12 years or older transplanted from 2006 to 2022, adjusting for recipient, donor, and transplant factors by inverse propensity weighting. Median allograft survival was 6.6 years in BLT compared to 5.3 years in SLT, a 25% risk-adjusted survival advantage of _0.81.3_1.8 years. Risk-adjusted bilateral survival advantages varied between 0.9 and 2.4 years across eleven subgroups. Median allograft survival in BLT was 1.2 years greater than right SLT and 2.0 years greater than left SLT. During the 16-year study period, allograft survival steadily improved for BLT but not for SLT. Although the 25% BLT survival advantage pre-dated the pandemic, COVID-19 may have contributed to an apparent SLT survival decline. Recognizing the possible influence of residual confounding due to selection biases, these findings may aid offer decision-making when both donor lungs are available.

Historically, liver transplant (LT) candidates with human immunodeficiency virus (HIV) have experienced high waitlist mortality. Since the HIV Organ Policy Equity (HOPE) Act expands access to organs from donors with HIV, we assessed the impact of HOPE on LT rate and wait time for this population. We linked data from a multicenter HOPE in Action study to Scientific Registry of Transplant Recipients (February 21, 2019 to June 1, 2024) and used Poisson regression to compare transplant rates among 99 candidates willing to accept HOPE donors (HOPE candidates) to 13 495 candidates with or without HIV not listed as willing to accept HOPE donors (non-HOPE candidates) matched on transplant center. The median time to any deceased donor liver transplant (DDLT) was 2.3 months for HOPE and 1.1 years for non-HOPE candidates. Within 2 years of listing, 90.9% of HOPE versus 58.5% of non-HOPE candidates received a DDLT (P < .001). HOPE was associated with an overall 3.11-fold higher DDLT incident rate ratio (95% CI 2.48-3.88, P < .001). Stratified by model for end-stage liver disease score categories 6 to 14, 15 to 24, 25 to 34, and 35 to 40/status 1; HOPE candidates had 10.12-fold, 5.31-fold, 1.41-fold and 2.90-fold higher DDLT rates, respectively. Willingness to accept livers from donors with HIV improves access to liver transplantation for candidates with HIV.

Liver transplant (LT) recipients experience a wide range of comorbidities, leading to frequent healthcare encounters. Until now, national registries, which have limited exposures and outcomes, and laborious small cohort studies have been the main data sources for LT research. Cosmos database offers electronic health record (EHR)-based insights into LT recipients at the national level with granular data. We evaluated if Cosmos data is representative of the entire US LT recipient population. Using Cosmos (N=20,235) and the national Scientific Registry of Transplant Recipients (SRTR) (N=51,281), we identified adult, first-time LT recipients between 7/2016-12/2022. We compared demographics, clinical data, and mortality across datasets, calculating Kaplan-Meier survival estimates and multi-variable Cox regressions. Recipient characteristics were highly comparable (e.g., female: Cosmos=36.5% vs. SRTR=36.4%, Black: 6.8% vs. 7.2%; BMI: 28.5 kg/m2 [24.8-32.9] vs. 28.2 [24.6-32.4]). Lab values were similar across cohorts, including MELD (24 [17-30] vs. 23 [16-30]). Transplant indications, donor characteristics, and 5-year survival (Cosmos 83.1% [82.3-83.8) vs. SRTR 80.9% [80.4-81.3]) were similar. The associations of clinical factors with survival were similar across both groups. Cosmos database demonstrated acceptable generalizability to the general US LT recipient population, which may advance LT research through a better understanding about LT recipients' experiences and outcomes.

BACKGROUND:Donor pool expansion is critical as lung candidates suffer high mortality, yet older donor lungs remain underutilized. We evaluated whether accepting an older donor (defined 4 ways: donor age 30-39, 40-49, 50-59, or 60-69 y) lung transplant was associated with a survival benefit over waiting for a younger donor offer. METHODS:Adult candidates who received a lung offer were identified using Scientific Registry of Transplant Recipients data, 2015-2022. Offers were categorized by donor age and candidate lung allocation score (LAS; <40, 40-55, >55). Postoffer mortality was compared between candidates for whom the offer was accepted ("acceptors") versus declined ("decliners") within each age-LAS category using weighted Cox regression. RESULTS:A total of 21 426 candidates received an offer from a donor age ≥30 y; 11 679 accepted. For LAS >55 candidates, a survival benefit was observed for acceptors of donors ages 30-39 y (weighted hazard ratio [wHR] of mortality: 0.450.520.59), 40-49 y (wHR: 0.610.700.79), and 50-59 y (wHR: 0.670.770.88); P < 0.001. For candidates with LAS 40-55, results suggest a survival benefit of accepting lung offers from donors age 30-39 y (wHR: 0.770.870.99) and 40-49 y (wHR: 0.760.870.99); P = 0.03. However, for candidates with LAS <40, a survival benefit was not observed for accepting any older donor transplant, with possible harm in accepting an age 50+ donor offer. CONCLUSIONS:Compared with declining and waiting for a younger donor offer, accepting an older donor lung transplant was associated with a survival advantage in candidates with high LAS in the precontinuous distribution era. Decision makers should consider these findings while recognizing potential changes in waiting time dynamics in the current era.