American Society of Transplant Surgeons Normothermic Regional Perfusion Standards: Abdominal.

BACKGROUND: Normothermic regional perfusion (NRP) has emerged as a vital technique in organ procurement, particularly in donation after circulatory death (DCD) cases, offering the potential to optimize organ utilization and improve posttransplant outcomes. Recognizing its significance, the American Society of Transplant Surgeons (ASTS) convened a work group to develop standardized recommendations for abdominal NRP in the United States. METHODS: The workgroup, comprising experts in NRP, DCD, and transplantation, formulated recommendations through a collaborative process involving revisions and approvals by relevant committees and the ASTS council. Four key areas were identified for standardization: Preprocedure communication, NRP procedure, Terminology and documentation, and Mentorship/credentialing. RESULTS: The recommendations encompass a range of considerations, including preprocedure communication protocols to facilitate informed decision-making by transplant centers and organ procurement organizations, procedural guidelines for NRP teams, uniform terminology to clarify the NRP process, and standards for mentorship and credentialing of NRP practitioners. Specific recommendations address logistical concerns, procedural nuances, documentation requirements, and the importance of ongoing quality assurance. CONCLUSIONS: The standardized recommendations for abdominal NRP presented in this article aim to ensure consistency, safety, and efficacy in the organ procurement process. By establishing clear protocols and guidelines, the ASTS seeks to enhance organ utilization, honor donor wishes, and uphold public trust in the donation process. Implementation of these recommendations can contribute to the advancement of NRP practices and improve outcomes for transplant recipients.

The Impact of Donor Body Mass Index on Safety and Outcomes in Living Donor Liver Transplantation: An Analysis of the National United States Database.

Background: The prevalence of obesity is rising in the general population. Donor obesity (body mass index ≥30 kg/m2) may potentially reduce the donor pool and impact outcomes in living donor liver transplantation (LDLT). Methods: We utilized the national transplant database to investigate the impact of donor obesity on donor and recipient outcomes. This was a retrospective cohort study of all LDLTs performed in the United States between January 2010 and June 2023. Outcomes of interest were analyzed by univariable and multivariable logistic regression. Patient and graft survival was evaluated using Kaplan-Meier and Cox proportional analysis. Results: Six hundred seventy-four donors with obesity and 3498 donors without obesity were analyzed. Donors with obesity had higher rates of readmission within 1 y of donation (15.9% versus 11.6%; P = 0.003). The risk of readmission was significantly different between 6 wk and 6 mo of donation (8.8% versus 5.9%; P = 0.036). Donor body mass index (odds ratio [OR], 1.460; 95% confidence interval [CI], 1.129-1.999; P = 0.004) and preoperative alkaline phosphatase levels (OR, 1.005; 95% CI, 1.000-1.011; P = 0.038) were independent predictors of donor readmission. High LDLT center volume was associated with reduced odds of donor readmission (OR, 0.509; 95% CI, 0.373-0.694; P < 0.001). Graft and recipient survival was comparable. Conclusions: Selection of living donors with obesity may be a potential avenue to increase the available donor pool without compromising recipient outcomes; however, they are at an increased risk for readmission between 6 wk and 6 mo of donation. The reason for readmission requires further study.

Lung Donation and Transplant Recipient Outcomes at Independent vs Hospital-Based Donor Care Units.

Importance: Centralizing deceased organ donor management and organ recovery into donor care units (DCUs) may mitigate the critical organ shortage by positively impacting donation and recipient outcomes. Objective: To compare donation and lung transplant outcomes between 2 common DCU models: independent (outside of acute-care hospitals) and hospital-based. Design, Setting, and Participants: This is a retrospective cohort study of Organ Procurement and Transplantation Network deceased donor registry and lung transplant recipient files from 21 US donor service areas with an operating DCU. Characteristics and lung donation rates among deceased donors cared for in independent vs hospital-based DCUs were compared. Eligible participants included deceased organ donors (aged 16 years and older) after brain death, who underwent organ recovery procedures between April 26, 2017, and June 30, 2022, and patients who received lung transplants from those donors. Data analysis was conducted from May 2023 to March 2024. Exposure: Organ recovery in an independent DCU (vs hospital-based DCU). Main Outcome and Measures: The primary outcome was duration of transplanted lung survival (through December 31, 2023) among recipients of lung(s) transplanted from cohort donors. A Cox proportional hazards model stratified by transplant year and program, adjusting for donor and recipient characteristics was used to compare graft survival. Results: Of 10 856 donors in the starting sample (mean [SD] age, 42.8 [15.2] years; 6625 male [61.0%] and 4231 female [39.0%]), 5149 (primary comparison group) underwent recovery procedures in DCUs including 1466 (28.4%) in 11 hospital-based DCUs and 3683 (71.5%) in 10 independent DCUs. Unadjusted lung donation rates were higher in DCUs than local hospitals, but lower in hospital-based vs independent DCUs (418 donors [28.5%] vs 1233 donors [33.5%]; P < .001). Among 1657 transplant recipients, 1250 (74.5%) received lung(s) from independent DCUs. Median (range) duration of follow-up after transplant was 734 (0-2292) days. Grafts recovered from independent DCUs had shorter restricted mean (SE) survival times than grafts from hospital-based DCUs (1548 [27] days vs 1665 [50] days; P = .04). After adjustment, graft failure remained higher among lungs recovered from independent DCUs than hospital-based DCUs (hazard ratio, 1.85; 95% CI, 1.28-2.65). Conclusions and Relevance: In this retrospective analysis of national donor and transplant recipient data, although lung donation rates were higher from deceased organ donors after brain death cared for in independent DCUs, lungs recovered from donors in hospital-based DCUs survived longer. These findings suggest that further work is necessary to understand which factors (eg, donor transfer, management, or lung evaluation and acceptance practices) differ between DCU models and may contribute to these differences.

Osteosarcoma Arising as a Secondary Malignancy following Treatment for Hematologic Cancer: A Report of 33 Affected Patients from the Cooperative Osteosarcoma Study Group (COSS).

PURPOSE: Osteosarcoma may arise as a secondary cancer following leukemias or lymphomas. We intended to increase the knowledge about such rare events. PATIENTS AND METHODS: We searched the Cooperative Osteosarcoma Study Group's database for individuals who developed their osteosarcoma following a previous hematological malignancy. The presentation and treatment of both malignancies was investigated, and additional neoplasms were noted. Outcomes after osteosarcoma were analyzed and potential prognostic factors were searched for. RESULTS: A total of 33 eligible patients were identified (male: 23, female: 10; median age: 12.9 years at diagnosis of hematological cancer; 20 lymphomas, 13 leukemias). A cancer predisposition syndrome was evident in one patient only. The hematological cancers had been treated by radiotherapy in 28 (1 unknown) and chemotherapy in 26 cases, including bone-marrow transplantation in 9. The secondary bone sarcomas (high-grade central 27, periosteal 2, extra-osseous 2, undifferentiated pleomorphic sarcoma of bone 2) arose after a median lag-time of 9.4 years, when patients were a median of 19.1 years old. Tumors were considered radiation-related in 26 cases (1 unknown). Osteosarcoma-sites were in the extremities (19), trunk (12), or head and neck (2). Metastases at diagnosis affected eight patients. Information on osteosarcoma therapy was available for 31 cases. All of these received chemotherapy. Local therapy involved surgery in 27 patients, with a good response reported for 9/18 eligible patients. Local radiotherapy was given to three patients. The median follow-up was 3.9 (0.3-12.0) years after bone tumor diagnosis. During this period, 21 patients had developed events as defined, and 15 had died, resulting in 5-year event-free and overall survival rates of 40% (standard error: 9%) and 56% (10%), respectively. There were multiple instances of additional neoplasms. Several factors were found to be of prognostic value (p < 0.05) for event-free (osteosarcoma site in the extremities) or overall (achievement of a surgical osteosarcoma-remission, receiving chemotherapy for the hematologic malignancy) survival. CONCLUSIONS: We were able to prove radiation therapy for hematological malignancies to be the predominant risk factor for later osteosarcomas. A resulting overrepresentation of axial and a tendency towards additional neoplasms affects prognosis. Still, selected patients may become long-term survivors with appropriate therapies, which is an argument against therapeutic negligence.

The Potential Utilization of Machine Perfusion to Increase Transplantation of Macrosteatotic Livers.

BACKGROUND: The demand for liver transplantation has led to the utilization of marginal grafts including moderately macrosteatotic livers (macrosteatosis ≥30% [Mas30]), which are associated with an elevated risk of graft failure. Machine perfusion (MP) has emerged as a technique for organ preservation and viability testing; however, little is known about MP in Mas30 livers. This study evaluates the utilization and outcomes of Mas30 livers in the era of MP. METHODS: The Organ Procurement and Transplantation Network database was queried to identify biopsy-proven Mas30 deceased donor liver grafts between June 1, 2016, and June 23, 2023. Univariable and multivariable models were constructed to study the association between MP and graft utilization and survival. RESULTS: The final cohort with 3317 Mas30 livers was identified, of which 72 underwent MP and were compared with 3245 non-MP livers. Among Mas30 livers, 62 (MP) and 1832 (non-MP) were transplanted (utilization of 86.1% versus 56.4%, P < 0.001). Donor and recipient characteristics were comparable between MP and non-MP groups. In adjusted analyses, MP was associated with significantly increased Mas30 graft utilization (odds ratio, 7.89; 95% confidence interval [CI], 3.76-16.58; P < 0.001). In log-rank tests, MP was not associated with 1- and 3-y graft failure (hazard ratio, 0.49; 95% CI, 0.12-1.99; P = 0.319 and hazard ratio 0.43; 95% CI, 0.11-1.73; P = 0.235, respectively). CONCLUSIONS: The utilization rate of Mas30 grafts increases with MP without detriment to graft survival. This early experience may have implications for increasing the available donor pool of Mas30 livers.

US Liver Transplant Outcomes After Normothermic Regional Perfusion vs Standard Super Rapid Recovery.

Importance: Normothermic regional perfusion (NRP) is an emerging recovery modality for transplantable allografts from controlled donation after circulatory death (cDCD) donors. In the US, only 11.4% of liver recipients who are transplanted from a deceased donor receive a cDCD liver. NRP has the potential to safely expand the US donor pool with improved transplant outcomes as compared with standard super rapid recovery (SRR). Objective: To assess outcomes of US liver transplants using controlled donation after circulatory death livers recovered with normothermic regional perfusion vs standard super rapid recovery. Design, Setting, and Participants: This was a retrospective, observational cohort study comparing liver transplant outcomes from cDCD donors recovered by NRP vs SRR. Outcomes of cDCD liver transplant from January 2017 to May 2023 were collated from 17 US transplant centers and included livers recovered by SRR and NRP (thoracoabdominal NRP [TA-NRP] and abdominal NRP [A-NRP]). Seven transplant centers used NRP, allowing for liver allografts to be transplanted at 17 centers; 10 centers imported livers recovered via NRP from other centers. Exposures: cDCD livers were recovered by either NRP or SRR. Main Outcomes and Measures: The primary outcome was ischemic cholangiopathy (IC). Secondary end points included primary nonfunction (PNF), early allograft dysfunction (EAD), biliary anastomotic strictures, posttransplant length of stay (LOS), and patient and graft survival. Results: A total of 242 cDCD livers were included in this study: 136 recovered by SRR and 106 recovered by NRP (TA-NRP, 79 and A-NRP, 27). Median (IQR) NRP and SRR donor age was 30.5 (22-44) years and 36 (27-49) years, respectively. Median (IQR) posttransplant LOS was significantly shorter in the NRP cohort (7 [5-11] days vs 10 [7-16] days; P < .001). PNF occurred only in the SRR allografts group (n = 2). EAD was more common in the SRR cohort (123 of 136 [56.1%] vs 77 of 106 [36.4%]; P = .007). Biliary anastomotic strictures were increased 2.8-fold in SRR recipients (7 of 105 [6.7%] vs 30 of 134 [22.4%]; P = .001). Only SRR recipients had IC (0 vs 12 of 133 [9.0%]; P = .002); IC-free survival by Kaplan-Meier was significantly improved in NRP recipients. Patient and graft survival were comparable between cohorts. Conclusion and Relevance: There was comparable patient and graft survival in liver transplant recipients of cDCD donors recovered by NRP vs SRR, with reduced rates of IC, biliary complications, and EAD in NRP recipients. The feasibility of A-NRP and TA-NRP implementation across multiple US transplant centers supports increasing adoption of NRP to improve organ use, access to transplant, and risk of wait-list mortality.

Mortality and morbidity after combined heart and liver transplantation in the failing Fontan: An updated dual center retrospective study.

INTRODUCTION: As the adult Fontan population with Fontan associated liver disease continues to increase, more patients are being referred for transplantation, including combined heart and liver transplantation. METHODS: We report updated mortality and morbidity outcomes after combined heart and liver transplant in a retrospective cohort series of 40 patients (age 14 to 49 years) with Fontan circulation across two centers from 2006-2022. RESULTS: The 30-day, 1-year, 5-year and 10-year survival rate was 90%, 80%, 73% and 73% respectively. Sixty percent of patients met a composite comorbidity of needing either post-transplant mechanical circulatory support, renal replacement therapy or tracheostomy. Cardiopulmonary bypass time > 283 min (4.7 h) and meeting the composite comorbidity were associated with mortality by Kaplan Meier analysis. CONCLUSION: Further study to mitigate early mortality and the above comorbidities as well as the high risk of bleeding and vasoplegia in this patient population is warranted.

National Trends in Utilization of Normothermic Machine Perfusion in DCD Liver Transplantation.

Background: In liver transplantation, advances in ex situ normothermic machine perfusion (NMP) have improved outcomes compared with traditional static cold storage (SCS) in donation after circulatory death (DCD) organs. We aimed to characterize trends in the utilization of NMP versus SCS in DCD liver transplantation in the United States. Methods: This retrospective cohort study used data from the United Network for Organ Sharing database to identify recipient-donor adult liver transplant pairs from DCD donors from January 2016 to June 2022. Utilization of NMP and changes in donor risk index (DRI) and components between NMP and SCS were assessed across transplant year eras (2016-2018, 2019-2020, and 2021-2022). Statistical comparisons were made using the Kruskal-Wallis test or the chi-square test. Results: A total of 3937 SCS and 127 NMP DCD donor transplants were included. Utilization of NMP ranged from ~0.4% to 3.5% from 2016 to 2021 and rose significantly to 11.2% in early 2022. Across transplant eras, median DRI increased significantly for SCS and NMP, but the magnitude of the increase was larger for NMP. With NMP DCDs, there were significant increases in median donor age, national share proportion, and "cold ischemic time" over time. Finally, there was a shift toward including higher DRI donors and higher model for end-stage liver disease score transplant recipients with NMP in later transplant eras. Conclusions: In recent years, NMP utilization has increased and expanded to donors with higher DRI and recipients with higher model for end-stage liver disease score at transplant, suggesting increasing familiarity and risk tolerance with NMP technology. As NMP remains a relatively new technique, ongoing study of patient outcomes, organ allocation practices, and utilization patterns is critical.

Characterizing proximity and transfers of deceased organ donors to donor care units in the United States.

Some United States organ procurement organizations transfer deceased organ donors to donor care units (DCUs) for recovery procedures. We used Organ Procurement and Transplantation Network data, from April 2017 to June 2021, to describe the proximity of adult deceased donors after brain death to DCUs and understand the impact of donor service area (DSA) boundaries on transfer efficiency. Among 19 109 donors (56.1% of the cohort) in 25 DSAs with DCUs, a majority (14 593 [76.4%]) were in hospitals within a 2-hour drive. In areas with DCUs detectable in the study data set, a minority of donors (3582 of 11 532 [31.1%]) were transferred to a DCU; transfer rates varied between DSAs (median, 27.7%, range, 4.0%-96.5%). Median hospital-to-DCU driving times were not meaningfully shorter among transferred donors (50 vs 51 minutes for not transferred, P < .001). When DSA boundaries were ignored, 3241 cohort donors (9.5%) without current DCU access were managed in hospitals within 2 hours of a DCU and thus potentially eligible for transfer. In summary, approximately half of United States deceased donors after brain death are managed in hospitals in DSAs with a DCU. Transfer of donors between DSAs may increase DCU utilization and improve system efficiency.

Performance of risk prediction models for post-liver transplant patient and graft survival over time.

Given liver transplantation organ scarcity, selection of recipients and donors to maximize post-transplant benefit is paramount. Several scores predict post-transplant outcomes by isolating elements of donor and recipient risk, including the donor risk index, Balance of Risk, pre-allocation score to predict survival outcomes following liver transplantation/survival outcomes following liver transplantation (SOFT), improved donor-to-recipient allocation score for deceased donors only/improved donor-to-recipient allocation score for both deceased and living donors (ID2EAL-D/-DR), and survival benefit (SB) models. No studies have examined the performance of these models over time, which is critical in an ever-evolving transplant landscape. This was a retrospective cohort study of liver transplantation events in the UNOS database from 2002 to 2021. We used Cox regression to evaluate model discrimination (Harrell's C) and calibration (testing of calibration curves) for post-transplant patient and graft survival at specified post-transplant timepoints. Sub-analyses were performed in the modern transplant era (post-2014) and for key donor-recipient characteristics. A total of 112,357 transplants were included. The SB and SOFT scores had the highest discrimination for short-term patient and graft survival, including in the modern transplant era, where only the SB model had good discrimination (C ≥ 0.60) for all patient and graft outcome timepoints. However, these models had evidence of poor calibration at 3- and 5-year patient survival timepoints. The ID2EAL-DR score had lower discrimination but adequate calibration at all patient survival timepoints. In stratified analyses, SB and SOFT scores performed better in younger (< 40 y) and higher Model for End-Stage Liver Disease (≥ 25) patients. All prediction scores had declining discrimination over time, and scores relying on donor factors alone had poor performance. Although the SB and SOFT scores had the best overall performance, all models demonstrated declining performance over time. This underscores the importance of periodically updating and/or developing new prediction models to reflect the evolving transplant field. Scores relying on donor factors alone do not meaningfully inform post-transplant risk.

Living Donor Liver Transplantation for Adults With High Model for End-stage Liver Disease Score: The US Experience.

BACKGROUND: Outcomes after living-donor liver transplantation (LDLT) at high Model for End-stage Liver Disease (MELD) scores are not well characterized in the United States. METHODS: This was a retrospective cohort study using Organ Procurement and Transplantation Network data in adults listed for their first liver transplant alone between 2002 and 2021. Cox proportional hazards models evaluated the association of MELD score (<20, 20-24, 25-29, and ≥30) and patient/graft survival after LDLT and the association of donor type (living versus deceased) on outcomes stratified by MELD. RESULTS: There were 4495 LDLTs included with 5.9% at MELD 25-29 and 1.9% at MELD ≥30. LDLTs at MELD 25-29 and ≥30 LDLT have substantially increased since 2010 and 2015, respectively. Patient survival at MELD ≥30 was not different versus MELD <20: adjusted hazard ratio 1.67 (95% confidence interval, 0.96-2.88). However, graft survival was worse: adjusted hazard ratio (aHR) 1.69 (95% confidence interval, 1.07-2.68). Compared with deceased-donor liver transplant, LDLT led to superior patient survival at MELD <20 (aHR 0.92; P = 0.024) and 20-24 (aHR 0.70; P < 0.001), equivalent patient survival at MELD 25-29 (aHR 0.97; P = 0.843), but worse graft survival at MELD ≥30 (aHR 1.68, P = 0.009). CONCLUSIONS: Although patient survival remains acceptable, the benefits of LDLT may be lost at MELD ≥30.

Acute abdomen in pediatric radiology. / Das akute Abdomen in der Kinderradiologie.

BACKGROUND: Imaging is a common part of the workup for acute abdomen in childhood and adolescence. Rapid diagnosis is crucial for adequate therapy, especially in young children. METHOD: This review is intended to provide an overview of the typical causes of acute abdomen in children and adolescents and is specifically aimed at radiologists who do not regularly work in pediatric radiology. RESULTS AND CONCLUSION: Age-specific peculiarities make a division into three age groups useful: Newborns, infants and toddlers, and schoolchildren. Possible causes of acute abdomen in children range from congenital lesions, particularly in newborns, to entities well known in adult radiology, more commonly in school-aged children. Since younger children have a higher sensitivity to radiation and often a limited ability to cooperate, sonography and conventional X-ray are the primary imaging modalities used. Decisive advantages of sonography, especially in younger children, include its widespread availability, the lack of need for sedation, and the possibility of bedside examination. Supplementary cross-sectional imaging, usually MRI, is reserved for special clinical questions. Close interdisciplinary cooperation between attending clinicians and radiologists is essential for efficient diagnostics in this patient group. KEY POINTS: · Age-specific features must be observed. · Sonography and radiography are the most important modalities. · Both congenital and acquired pathologies play a role. · Good interdisciplinary cooperation is essential in this patient group. CITATION FORMAT: · Lochbühler N, Bölle P, Müller-Abt P. Acute abdomen in pediatric radiology. Fortschr Röntgenstr 2024; 196: 451 - 462.

Deceased Organ Donor Management and Organ Distribution From Organ Procurement Organization-Based Recovery Facilities Versus Acute-Care Hospitals.

Introduction: Organ recovery facilities address the logistical challenges of hospital-based deceased organ donor management. While more organs are transplanted from donors in facilities, differences in donor management and donation processes are not fully characterized. Research Question: Does deceased donor management and organ transport distance differ between organ procurement organization (OPO)-based recovery facilities versus hospitals? Design: Retrospective analysis of Organ Procurement and Transplant Network data, including adults after brain death in 10 procurement regions (April 2017-June 2021). The primary outcomes were ischemic times of transplanted hearts, kidneys, livers, and lungs. Secondary outcomes included transport distances (between the facility or hospital and the transplant program) for each transplanted organ. Results: Among 5010 deceased donors, 51.7% underwent recovery in an OPO-based recovery facility. After adjustment for recipient and system factors, mean differences in ischemic times of any transplanted organ were not significantly different between donors in facilities and hospitals. Transplanted hearts recovered from donors in facilities were transported further than hearts from hospital donors (median 255 mi [IQR 27, 475] versus 174 [IQR 42, 365], P = .002); transport distances for livers and kidneys were significantly shorter (P < .001 for both). Conclusion: Organ recovery procedures performed in OPO-based recovery facilities were not associated with differences in ischemic times in transplanted organs from organs recovered in hospitals, but differences in organ transport distances exist. Further work is needed to determine whether other observed differences in donor management and organ distribution meaningfully impact donation and transplantation outcomes.

Significant Reduction in Posttransplant Hepatocellular Carcinoma Recurrence in the Post 6-Mo Waiting Policy Era.

BACKGROUND: In 2015, the United Network for Organ Sharing implemented a policy introducing a 6-mo waiting period before granting model for end-stage liver disease exception points to liver transplant (LT) candidates with hepatocellular carcinoma (HCC). This study analyzes the policy impact on post-LT HCC recurrence. METHODS: This was a United Network for Organ Sharing retrospective cohort study of patients with HCC who underwent LT from January 1, 2010, to May 31, 2019. HCC-specific data included alpha-fetoprotein, tumor characteristics, locoregional therapy (LRT), and explant data used to calculate the Risk Estimation of Tumor Recurrence After Transplant score. The primary exposure was pre-/post-policy era, divided on October 8, 2015. Survival analysis techniques were used to evaluate the unadjusted and sequentially adjusted association between policy era and HCC recurrence, accounting for competing risks. RESULTS: A total of 7940 patients were included, 5879 (74.0%) pre-policy era and 2061 (26.0%) post-policy era. Post-policy patients were older, received more LRT, and had lower alpha-fetoprotein levels and smaller tumor sizes at transplant. Incidence rates of HCC recurrence were 19.8 and 13.7 events per 1000 person-years for pre- and post-policy eras, respectively. Post-policy era was associated with an unadjusted 35% reduction in the risk of HCC recurrence (P < 0.001). After adjusting for recipient, donor, and tumor characteristics at listing this association remained (subhazard ratio 0.69; 95% confidence interval, 0.55-0.86; P = 0.001); however, after additionally adjusting for LRT episodes and Risk Estimation of Tumor Recurrence After Transplant score, there was no longer a statistically significant association (subhazard ratio 0.77; 95% confidence interval, 0.59-1.00; P = 0.054). CONCLUSIONS: We observed a significant reduction in post-LT HCC recurrence after policy implementation. This may be due to waitlist selection of healthier patients, increased LRT utilization, and potential selection of favorable tumor biology.