Dual kidney transplants from adult marginal donors: Review and perspective

Abstract

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. K E Y W O R D Sdual kidney transplants, index, kidney discard, kidney donor profile marginal deceased donors, nephron mass INTRODUCTIONFor patients with end stage renal disease (ESRD), kidney transplantation is associated with extended life expectancy, improved quality of life, and has proven to be cost-effective long-term compared to any type of dialysis. 1-6 As of August 2021, the United Network for Organ Sharing (UNOS) national waiting list for solid organ transplantation had nearly 107 000 total candidates, including > 90 000 patients (84.6%) awaiting kidney transplantation. 7 Unfortunately, only 22 817 kidney

Long‐term outcomes of kidney transplantation from deceased donors with terminal acute kidney injury: Single center experience and literature review

“…Consequently, there was a selection bias in donors with AKI favoring younger age, lower KDPI, and absence of hypertension or diabetes. However, over time and with increased experience and application of dual kidney transplantation, some of the above criteria were liberalized to include ECD ( n = 24) and DCD ( n = 10) donors as well as higher terminal SCr levels ( N = 36 with terminal SCr ≥4.0 mg/dl) 29,30 . Donors who were either anuric or on renal replacement therapy were excluded.…”

“…The Cockcroft–Gault formula was employed to estimate adult DD creatinine clearance, using both the admission and terminal donor SCr level and adjusted body weight to calculate a range of DD kidney function in order to determine single or dual kidney transplantation into a single recipient 29,30 . If the estimated DD creatinine clearance was >65 ml/min, then a single kidney transplant was usually performed.…”

“…Pump parameters were also used in decision‐making with respect to kidney utilization. If pump flows were <60–80 ml/min or resistances were > .4 –.5 mm Hg/ml, then the kidneys were considered for dual transplantation 29,30 …”

Clinical Phenotypes of Dual Kidney Transplant Recipients in the United States as Identified through Machine Learning Consensus Clustering

“…DKT, the transplantation of two kidneys from the same donor into a single recipient, has been utilized as an alternative approach to expand the available donor pool [7,11]. Many reports show that the graft survival rate was higher in the DKT recipients than in those single kidney transplant (SKT) with ECD or high KDPI kidney [11,12,15,19].…”

“…However, there is a large gap between the number of patients receiving a transplant and the number of people waiting due to a limited number of donor organs [4,5]. Moreover, after the Organ Procurement and Transplantation Network (OPTN) introduced the kidney donor profile index (KDPI) as a new national deceased donor kidney allocation policy in 2013 [6], the kidney discard rate in the US greatly rose from 10% in 1998 to 21% in 2020 [7]. As a result, there have been ongoing efforts by the transplant community to increase the size of the deceased donor pool by using more kidneys from expanded criteria (ECD) and high KDPI donors, donation after cardiocirculatory death donors, as well as standard criteria donors with prolonged warm or cold ischemic times (CIT), acute kidney injury donors, and donors at the extremes of age [7].…”