Allocation System Change Research Articles

Comparison of Six-Month Outcomes in Patients Bridged to Heart Transplantation with an Intra-Aortic Balloon Pump before and after the UNOS Allocation System Change

We report the trends in utilization and outcomes of intra-aortic balloon pump (IABP) as a bridge to heart transplantation (HT) in the six-month period immediately before and after the implementation of the revised United Network of Organ Sharing (UNOS) allocation system in October 2018. The UNOS database was queried for HT candidates who required temporary mechanical circulatory support with IABP who were transplanted within a 6-month time window before (N=125) and after (N=193) the UNOS allocation change. Demographics, comorbidities, hemodynamics, and post-HT mortality were compared using standard statistical methods. Multivariate Cox proportional hazard regression analysis (adjusted for age, sex, diabetes, ethnicity, ischemic time, dialysis, life support and HLA mismatch) was also performed for survival analysis. Mean age between the before and after groups, respectively, was similar (54.8 ± 12.0 vs. 54.2 ± 13.2 years, p=0.7). No significant differences were identified in recipient demographics, comorbidities, renal function or invasive hemodynamics at time of transplantation. There were no statistically significant differences in donor age or donor organ ischemic time. Total waitlist time was lower in the post-policy change group (median [inter-quartile range], 10.0 [5.0, 26.0] vs. 31.0 [11.0, 87.0] days; p<0.001). Additionally, there was no difference in post-HT mortality in the post-policy change group (5 vs. 4 deaths, p=0.16). The number of HT candidates on IABP at the time of HT has increased following implementation of the new UNOS allocation system with a concurrent reduction in candidate waitlist time, but no difference in post-HT mortality.

The Safety and Efficacy Intra-Aortic Balloon Pump as a Bridge to Transplant Strategy under the New UNOS Allocation

Introduction We report the safety and efficacy of the IABP as a bridge to orthotopic heart transplantation (OHT) since the United Network of Organ Sharing (UNOS) instituted its updated organ allocation system on October 18th, 2018. Methods This is single-center retrospective analysis reporting the feasibility, safety, and efficacy of the use of IABP as a bridge to OHT. All patients in this study were admitted with cardiogenic shock to the heart failure ICU with an average cardiac index of 1.73±0.22 L/min/m2 and met criteria for hemodynamic support with IABP placement. Results The cohort consisted of 20 consecutive patients with IABP as a bridge to transplant (BTT). Mean age was 50 years old, 65% male, 60% non-ischemic, 20% ischemic, 10% congenital (CC-TGA), and 10% restrictive cardiomyopathy. The rate of successful axillary IABP insertion was 100%, with the majority from a percutaneous approach (15/16) and one via surgical graft. Of the original cohort, 17 patients were successfully bridged to OHT (axillary IABP n=14, femoral IABP n=3), 1 patient who did not have a contraindication to durable MCS received a BTT LVAD after 30 days of IABP support, and 2 patients required upgrade to higher levels of MCS support (Fig 1). All patients with axillary IABP placement ambulated with a physical therapist while awaiting OHT. There were no neurologic events, major bleeding, infections, or death. Balloon rupture necessitating urgent balloon replacement occurred in 15% of patients, and one patient with a femoral IABP required surgical thrombectomy of the common femoral artery. The mean total days with IABP before transplantation or LVAD was 12, with range of 2-30 days (Fig 2). Conclusion Since the recent change in the heart transplant allocation system, we report the largest series, to our knowledge, of patients being bridged to OHT with IABP, the majority of which are axillary. We demonstrate that IABP is a safe and effective platform of support for patients awaiting OHT, and furthermore, we demonstrate the feasibility of the axillary IABP approach.

Post-Cardiac Transplant Survival of Patients Supported by the Heartmate 3 Devices: A UNOS Analysis

Introduction Post cardiac transplant outcomes of patients supported with the Heartmate 3 left ventricular assist device (LVAD) have not been previously reported. The purpose of this analysis was to report status at the time of transplant and survival by continuous flow (CF) device type. Hypothesis Patients supported with a HeartMate 3 LVAD will have a similar post-transplant survival to other contemporary CF-LVADs. Methods The study cohort included adult patients supported on contemporary, continuous flow (CF) devices in the UNOS registry who underwent cardiac transplant between the years 2014-2018, prior to the 2018 UNOS allocation system change. The analysis was limited to patients who underwent initial LVAD implantation in 2014 and beyond to allow post-transplant comparisons among patients with similar LVAD support times. Multivariable cox regression was performed to assess the association between LVAD type and post-transplant survival. Results The study cohort consisted of 3,117 patients who underwent cardiac transplant while on LVAD support (Heartmate 2: 1,545, Heartmate 3: 179, HeartWare (HVAD): 1,393). No patients supported on Heartmate 3 devices were transplanted for pump thrombosis during this time period. Patients supported on the Heartmate 3 were less likely to be listed 1A for complications at the time of transplant (Heartmate3: 28 % (51/179), Heartmate 2: 44 % (680/1,545), HVAD 37 % (511/1,393, p Conclusions Patients supported with Heartmate 3 LVAD at the time of transplant have similar survival after transplant compared to other contemporary CF devices in this early experience. No patients with a Heartmate 3 were transplanted for device thrombosis.

United Network for Organ Sharing Rule Changes and Their Effects on Kidney and Liver Transplant Outcomes.

Recent national organ distribution rule changes could have implications on distance between donor and recipient hospitals and cold ischemia time. With cold ischemia time being an unavoidable detriment to organ quality, any strategies that minimize it should maximize organ quality. This study evaluated the significance of the kidney allocation system and the Share 35 rule changes on kidney and liver transplant outcomes. This retrospective study included deceased liver and kidney donor and their recipient data from the Organ Procurement and Transplantation Network. Variables were analyzed using propensity score matching and Cox hazards model distance (from donor hospital to organ recovery center), and effects on survival outcomes of trans-planted livers and kidneys in the context of the recent rule changes were analyzed. Transplanted organs have significantly better outcomes when the distance is 0 miles versus median distances for locally transported organs of 18 and 22 miles for kidney and liver, respectively. Cold ischemia time, when corrected, accounts for this finding, thus suggesting that cold ischemia time is the factor most responsible for viability of a transplanted organ. This significance remains evident for liver transplants even after the Share 35 rule change but not for kidney transplants following the December 2014 kidney allocation system change. Liver transplants showed a higher risk of lower viability with travel, and the Share 35 rule did not appear to change this result. Kidney transplant outcomes appear to have improved after the kidney allocation system change. Potential strategies for minimizing cold ischemia time and improving outcomes include more free-standing organ recovery centers in centralized locations.

Living-related lung transplantation.

Living-donor lobar lung transplantation (LDLLT) was developed to deal with the severe shortage of brain dead door for patients who would not survive the long waiting period. In standard LDLLT, right and left lower lobes removed from two healthy donors are implanted into a recipient after right and left pneumonectomies using cardiopulmonary bypass (CPB). The number of LDLLT has decreased in the USA due to the recent change in allocation system for cadaveric donor lungs. For the past several years, most of the reports on LDLLT have been from Japan, where the average waiting time for a cadaveric lung is exceeding 800 days. LDLLT has been performed both for adult and pediatric patients suffering from various end-stage lung diseases including restrictive, obstructive, vascular and infectious lung diseases. Since only two lobes are implanted, size matching is a very important issue. Functional size matching by measuring donor pulmonary function and anatomical size matching by three-dimensional computed tomography (3D-CT) volumetry are very useful. For oversize graft, we have employed several techniques, including single lobe transplantation, delayed chest closure, downsizing the graft, and middle lobe transplantation. In cases of undersize mismatch, native upper lobe sparing transplant or right-left inverted transplant was performed. The 5-, 10- and 15-year survivals were 80.8%, 72.6% and 61.7%, respectively. There was no difference in survival between standard LDLLT and non-standard LDLLT such as single, sparing and inverted transplant. All donors have been discharged without any restrictions. LDLLT is a viable option for very ill patients who would not survive a long waiting time for cadaveric lungs. We have successfully developed various surgical techniques to overcome size mismatching with favorable outcome.

Aggressive National Placement Efforts Increase Utilization of High KDPI Kidneys Post Kidney Allocation System (KAS) Changes

Aggressive National Placement Efforts Increase Utilization of High KDPI Kidneys Post Kidney Allocation System (KAS) Changes

The effects of Share 35 on the cost of liver transplantation.

On June 18, 2013, the United Network for Organ Sharing (UNOS) instituted a change in the liver transplant allocation policy known as "Share 35." The goal was to decrease waitlist mortality by increasing regional sharing of livers for patients with a model for end-stage liver disease (MELD) score of 35 or above. Several studies have shown Share 35 successful in reducing waitlist mortality, particularly in patients with high MELD. However, the MELD score at transplant has increased, resulting in sicker patients, more complications, and longer hospital stays. Our study aimed to explore factors, along with Share 35, that may affect the cost of liver transplantation. Our results show Share 35 has come with significantly increased cost to transplant centers across the nation, particularly in regions 2, 5, 10, and 11. Region 5 was the only region with a median MELD above 35 at transplant, and cost was significantly higher than other regions. Several other recipient factors had changes with Share 35 that may significantly affect the cost of liver transplant. While access to transplantation for the sickest patients has improved, it has come at a cost and regional disparities remain. Financial implications with proposed allocation system changes must be considered.

The ASCENT (Allocation System Changes for Equity in Kidney Transplantation) Study: A Randomized Effectiveness-Implementation Study to Improve Kidney Transplant Waitlisting and Reduce Racial Disparity

IntroductionThe United Network for Organ Sharing (UNOS) implemented a new Kidney Allocation System (KAS) in December 2014 that is expected to substantially reduce racial disparities in kidney transplantation among waitlisted patients. However, not all dialysis facility clinical providers and end-stage renal disease (ESRD) patients are aware of how the policy change could improve access to transplantation.MethodsWe describe the ASCENT (Allocation System Changes for Equity in Kidney Transplantation) study, a randomized, controlled effectiveness-implementation study designed to test the effectiveness of a multicomponent intervention to improve access to the early steps of kidney transplantation among dialysis facilities across the United States. The multicomponent intervention consists of an educational webinar for dialysis medical directors, an educational video for patients and an educational video for dialysis staff, and a dialysis facility−specific transplantation performance feedback report. Materials will be developed by a multidisciplinary dissemination advisory board and will undergo formative testing in dialysis facilities across the United States.ResultsThis study is estimated to enroll ∼600 US dialysis facilities with low waitlisting in all 18 ESRD networks. The co-primary outcomes include change in waitlisting and waitlist disparity at 1 year; secondary outcomes include changes in facility medical director knowledge about KAS, staff training regarding KAS, patient education regarding transplantation, and the intent of the medical director to refer patients for transplantation evaluation.DiscussionThe results from the ASCENT study will demonstrate the feasibility and effectiveness of a multicomponent intervention designed to increase access to the deceased donor kidney waitlist and to reduce racial disparities in waitlisting.

Consequences of the change in Eurotransplant allocation system on kidney allocation in children

Consequences of the change in Eurotransplant allocation system on kidney allocation in children