Optimization of expanded donors using dual kidney transplantation: case-control study

Dual kidney transplants from adult marginal donors: Review and perspective

The practice of dual kidney transplantation (DKT) from adult marginal deceased donors (MDDs) dates back to the mid-1990s with initial pioneering experiences reported by the Stanford and Maryland groups, at which time the primary indication was estimated insufficient nephron mass from older donors. Multiple subsequent studies of short and long-term success have been reported focusing on three major aspects of DKT: Identifying appropriate selection criteria and developing scoring systems based on pre- and post-donation factors; refining technical aspects; and analyzing mid-term outcomes. The number of adult DKTs performed in the United States has declined in the past decade and only about 60 are performed annually. For adult deceased donor kidneys meeting double allocation criteria, >60% are ultimately not transplanted. Deceased donors with limited renal functional capacity represent a large proportion of potential kidneys doomed to either discard or non-recovery. However, DKT may reduce organ discard and optimize the use of kidneys from MDDs. In an attempt to promote utilization of MDD kidneys, the United Network for Organ Sharing introduced new allocation guidelines pursuant to DKT in 2019. The purpose of this review is to chronicle the history of DKT and identify opportunities to improve utilization of MDD kidneys through DKT. This article is protected by copyright. All rights reserved.

Utilization and Outcomes of Single and Dual Kidney Transplants from Older Deceased Donors in the United Kingdom

BACKGROUND AND OBJECTIVES

Kidneys from elderly deceased donors are often discarded after procurement if the expected outcomes from single kidney transplantation are considered unacceptable. An alternative is to consider them for dual kidney transplantation. We aimed to examine the utilization of kidneys from donors aged ≥60 years in the United Kingdom and compare clinical outcomes of dual versus single kidney transplant recipients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from the United Kingdom Transplant Registry from 2005 to 2017 were analyzed. We examined utilization rates of kidneys retrieved from deceased donors aged ≥60 years, and 5-year patient and death-censored graft survival of recipients of dual and single kidney transplants. Secondary outcomes included eGFR. Multivariable analyses and propensity score analysis were used to correct for differences between the groups.

RESULTS

During the study period, 7841 kidneys were procured from deceased donors aged ≥60 years, of which 1338 (17%) were discarded; 356 dual and 5032 single kidneys were transplanted. Donors of dual transplants were older (median, 73 versus 66 years; P<0.001) and had higher United States Kidney Donor Risk Indices (2.48 versus 1.98; P<0.001). Recipients of dual transplants were also older (64 versus 61 years; P<0.001) and had less favorable human leukocyte antigen matching (P<0.001). After adjusting for confounders, dual and single transplants had similar 5-year graft survival (hazard ratio, 0.81; 95% CI, 0.59 to 1.12). No difference in patient survival was demonstrated. Similar findings were observed in a matched cohort with a propensity score analysis method. Median 12-month eGFR was significantly higher in the dual kidney transplant group (40 versus 36 ml/min per 1.73 m²; P<0.001).

CONCLUSIONS

Recipients of kidneys from donors aged ≥60 years have similar 5-year graft survival and better graft function at 12 months with dual compared with single deceased donor kidney transplants.

[Evaluation of single kidney graft outcome in patients initially programmed for a dual kidney graft transplantation]

INTRODUCTION

Kidney transplantation is championed as the gold standard treatment for patients with end-stage kidney disease. According to the biomedical agency, there is an increasing number of patients waiting for kidney transplantation. Faced with organ shortage, the use of marginal grafts may well increase the number of available kidney grafts. Occasionally, during dual kidney graft transplantation, the poor quality of one of the two grafts, or other specific circumstances, may lead to transplantation of only one of the two grafts. We have compared patient outcome concerning single kidney transplantation from an initial dual kidney graft with respect to dual kidney graft transplantation.

MATERIAL

Among 67 patients enrolled for a dual kidney graft, 39 dual kidney grafts (group 1) were compared with 12 grafts performed with only one of the two kidneys of a dual kidney graft (group 2) as well as 15 grafts performed following a classic kidney graft protocol (group 3).

RESULTS

The survival of grafts was respectively for groups 1, 2 and 3 of 100%, 72,5% and 75,4% (P=0.17). The survival of patients was respectively for groups 1, 2 and 3 of 78.3%, 89.9% and 87.8% (P=0.47).

CONCLUSION

Our study suggests that transplantation of a single kidney, initially proposed as dual kidney graft candidate, has satisfying results in terms of graft survival and patient mortality at the expense of poorer renal function in comparison to dual kidney graft. Indeed, there was no significant difference in the survival of patients and grafts. This seems promising taking into consideration that the aim of transplantation in elderly recipients is primarily to avoid dialysis, rather than having optimal post-transplantation kidney function.

LEVEL OF EVIDENCE

4.

Recent Innovations in Kidney Transplants

Current donor pool utilization is unable to meet the high demand for kidney transplants. Donor pool expansion using expanded-criteria donors and dual kidney transplantation are viable options. Advances in diagnosing antibody-mediated rejection and targeting immunosuppression increase long-term transplantation success. Further exploration of minimally invasive surgical techniques, kidney bioengineering, and artificial-implantable renal devices hold promise for the future.

Strategies for an Expanded Use of Kidneys From Elderly Donors

The old-for-old allocation policy used for kidney transplantation (KT) has confirmed the survival benefit compared to remaining listed on dialysis. Shortage of standard donors has stimulated the development of strategies aimed to expand acceptance criteria, particularly of kidneys from elderly donors. We have systematically reviewed the literature on those different strategies. In addition to the review of outcomes of expanded criteria donor or advanced age kidneys, we assessed the value of the Kidney Donor Profile Index policy, preimplantation biopsy, dual KT, machine perfusion and special immunosuppressive protocols. Survival and functional outcomes achieved with expanded criteria donor, high Kidney Donor Profile Index or advanced age kidneys are poorer than those with standard ones. Outcomes using advanced age brain-dead or cardiac-dead donor kidneys are similar. Preimplantation biopsies and related scores have been useful to predict function, but their applicability to transplant or refuse a kidney graft has probably been overestimated. Machine perfusion techniques have decreased delayed graft function and could improve graft survival. Investing 2 kidneys in 1 recipient does not make sense when a single KT would be enough, particularly in elderly recipients. Tailored immunosuppression when transplanting an old kidney may be useful, but no formal trials are available.Old donors constitute an enormous source of useful kidneys, but their retrieval in many countries is infrequent. The assumption of limited but precious functional expectancy for an old kidney and substantial reduction of discard rates should be generalized to mitigate these limitations.

Dual kidney transplantation involving organs from expanded criteria donors: a review of our series and an update on current indications

BACKGROUND

Our purpose was to review our kidney transplantation program based on the use of expanded criteria donors, and to determine current indications for dual kidney transplantation (DKT). In 1996, a program was initiated to transplant kidneys from donors of over 60 years performing single or dual transplantation.

METHODS

In 1996, a program was initiated to transplant kidneys from donors of over 60 years performing single or dual transplantation. DKT were performed with donors >75 and donors between 60 and 74 years of age and glomerulosclerosis of >15%. The kidneys of donors between 60 and 74 years of age and with glomerulosclerosis of <15% were used for single kidney transplantation (SKT). In 2005, we started to perform SKT despite glomerulosclerosis being >15%, taking into account donor and recipient characteristics.

RESULTS

From 1996 to 2004, 222 SKTs and 88 DKTs were performed. Graft survival after 1 and 4 years was, respectively, 91% and 78% for SKT and 95% and 79% for DKT. In 2005, we started to perform SKT despite glomerulosclerosis being >15%, taking into account donor and recipient characteristics. From 2005 to 2011, 328 SKT and 32 DKT were performed. During this period most kidneys used for DKT were from female donors >75 years old, weighing <65 kg, with a creatinine of >1 mg/dL and glomerulosclerosis of >15%. The recipients for DKT were mostly male, <70 years old and whose weight was >75 kg.

CONCLUSION

DKT from expanded criteria donors shows good outcomes. However, in many cases SKT may fulfill the need of the recipient. The archetype for DKT is an older female weighing <65 kg and the most common recipient is an overweight male who is <70 years old.