Single vs dual(en bloc) kidney transplants from donors ≤ 5 years of age: A single center experience

AIM: To compare outcomes between single and dual en bloc(EB) kidney transplants(KT) from small pediatric donors. METHODS: Monocentric nonprospective review of KTs from pediatric donors ≤ 5 years of age. Dual EB KT was defined as keeping both donor kidneys attached tothe inferior vena cava and aorta, which were then used as venous and arterial conduits for the subsequent transplant into a single recipient. Donor age was less useful than either donor weight or kidney size in decision-making for kidney utilization as kidneys from donors < 8 kg or kidneys < 6 cm in length were not transplanted. Post-transplant management strategies were standardized in all patients.RESULTS: From 2002-2015, 59 KTs were performed including 34 dual EB and 25 single KTs. Mean age of donors(17 mo vs 38 mo, P < 0.001), mean weight(11.0 kg vs 17.4 kg, P = 0.046) and male donors(50% vs 84%, P = 0.01) were lower in the dual EB compared to the single KT group, respectively. Mean cold ischemia time(21 h), kidney donor profile index(KDPI; 73% vs 62%) and levels of serum creatinine(SCr, 0.37 mg/d L vs 0.49 mg/d L, all P = NS) were comparable in the dual EB and single KT groups, respectively. Actuarial graft and patient survival rates at 5-years follow-up were comparable. There was one case of thrombosis resulting in graft loss in each group. Delayed graft function incidence(12% dual EB vs 20% single KT, P = NS) was slightly lower in dual EB KT recipients. Initial duration of hospital stay(mean 5.4 d vs 5.6 d) and the one-year incidences of acute rejection(6% vs 16%), operative complications(3% vs 4%), and major infection were comparable in the dual EB and single KT groups, respectively(all P = NS). Mean 12 mo SCr and abbreviated MDRD levels were 1.17 mg/d L vs 1.35 mg/d L and 72.5 m L/min per 1.73 m^2 vs 60.5 m L/min per 1.73 m^2(both P = NS) in the dual EB and single KT groups, respectively. CONCLUSION: By transplanting kidneys from young pediatric donors into adult recipients, one can effectively expand the limited donor pool and achieve excellent medium-term outcomes.

Kidney transplantation in older recipients:Preemptive high KDPI kidney vs lower KDPI kidney after varying dialysis vintage

AIM To evaluate the outcomes of transplanting marginal kidneys preemptively compared to better-quality kidneys after varying dialysis vintage in older recipients.METHODS Using OPTN/United Network for Organ Sharing database from 2001-2015, we identified deceased donor kidney(DDK) transplant recipients > 60 years of age who either underwent preemptive transplantation of kidneys with kidney donor profile index(KDPI) ≥ 85%(marginal kidneys) or received kidneys with KDPI of 35%-84%(better quality kidneys that older wait-listed patients would likely receive if waited longer) after being on dialysis for either 1-4 or 4-8 years. Using a multivariate Cox model adjusting for donor, recipient and transplant related factors-overall and death-censored graft failure risks along with patient death risk of preemptive transplant recipients were compared to transplant recipients in the 1-4 and 4-8 year dialysis vintage groups.RESUTLS The median follow up for the whole group was 37 mo(interquartile range of 57 mo). A total of 6110 DDK transplant recipients above the age of 60 years identified during the study period were found to be eligible to be included in the analysis. Among these patients350 received preemptive transplantation of kidneys with KDPI ≥ 85. The remaining patients underwent transplantation of better quality kidneys with KDPI 35-84% after being on maintenance dialysis for either 1-4 years(n = 3300) or 4-8 years(n = 2460). Adjusted overall graft failure risk and death-censored graft failure risk in preemptive high KDPI kidney recipients were similar when compared to group that received lower KDPI kidney after being on maintenance dialysis for either 1-4 years(HR 1.01, 95%CI: 0.90-1.14, P = 0.84 and HR 0.96, 95%CI: 0.79-1.16, P = 0.66 respectively) or 4-8 years(HR 0.82, 95%CI: 0.63-1.07, P = 0.15 and HR 0.81, 95%CI: 0.52-1.25, P = 0.33 respectively). Adjusted patient death risk in preemptive high KDPI kidney recipients were similar when compared to groups that received lower KDPI kidney after being on maintenance dialysis for 1-4 years(HR 0.99, 95%CI: 0.87-1.12, P = 0.89) but lower compared to patients who were on dialysis for 4-8 years(HR 0.74, 95%CI: 0.56-0.98, P = 0.037).CONCLUSION In summary, our study supports accepting a "marginal" quality high KDPI kidney preemptively in older waitlisted patients thus avoiding dialysis exposure.

Histological and clinical evaluation of marginal donor kidneys before transplantation: Which is best?

Organ shortage represents one of the major limitations to the development of kidney transplantation.To increase the donor pool and to answer the ever increasing kidney request,physicians are recurring to marginal kidneys as kidneys from older donors,from hypertensive or diabetic donors and from nonheart beating donors.These kidneys are known to have frequently a worse outcome in the recipients.To date major problem is to evaluate such kidneys in order to use or to discard them before transplantation.The use of such kidneys create other relevant question as whether to use them as single or dual transplant and to allocate them fairly according transplant programs.The pre-transplant histological evaluation,the clinical evaluation of the donor or both the criteria joined has been used and according the time each criterion prevailed over the others.Aim of this review has been to examine the advantages and the drawbacks of any criterion and how they have changed with time.To date any criterion has several limitations and several authors have argued for the development of new guidelines in the field of the kidney evaluation for transplantation.Several authors argue that the use of omic technologies should improve the organ evaluation and studies are ongoing to evaluate these technologies either in the donor urine or in the biopsies taken before transplantation.

Changing organ allocation policy for kidney transplantation in the United States

The new kidney allocation scheme(KAS) in effect since December 4th 2014 was designed to overcome the shortcomings of previous system. A key feature of the new KAS is preferential allocation of best quality organs to wait-list candidates with the longest predictivesurvival in a concept called longevity matching. Highly sensitized recipients would get extra points and enjoy widespread sharing of organs in order to increase accessibility to transplant. Wait-list candidates with blood group B will be offered organs from donors with A2 and A2 B blood type in order to shorten their wait-list time. Time on the wait list will start from day of listing or date of initiation of dialysis whichever comes first which should benefit candidates with limited resources who might be late to get on the transplant list. Pay back system has been eliminated in the new KAS. These changes in organ allocation policy may lead to increase in median half-life of the allograft and increase the number of transplants; thus resulting in better utilization of a scarce resource. There could be unintended negative consequences which may become evident over time.

成人供者双肾移植的临床应用及进展

充分利用边缘供者器官是扩大供者池、缓解器官短缺的重要手段。经过恰当的供者评估、分配和受者选择,成人供者双肾移植(DKT)既可以获得与单肾移植(SKT)类似的临床效果,又能有效降低边缘供肾的弃用率。本文对成人供者DKT的临床应用和进展做一综述,从DKT的发展概况、分配标准、受者选择、手术方式及外科并发症、临床效果等方面进行阐述,旨在为今后开展边缘供者DKT工作提供借鉴与指导。

Blessing and a curse of outpatient management of delayed graft function

Delayed graft function (DGF) is a common complication occurring most often after deceased donor kidney transplant with several donor characteristics as well as immunologic factors that lead to its development post-transplant.These patients require dialysis and close kidney function monitoring until sufficient allograft function is achieved.This has resulted in limited options for DGF management,either prolonged hospitalization until graft function improves to the point where dialysis is no longer needed or discharge back to their home dialysis unit with periodic follow up in the transplant clinic.DGF is associated with a higher risk for acute rejection,premature graft failure,and 30-d readmission;therefore,these patients need close monitoring,immunosuppression management,and prompt allograft biopsy if prolonged DGF is observed.This may not occur if these patients are discharged back to their home dialysis unit.To address this issue,the University of Wisconsin-Madison created a clinic in 2011 specialized in outpatient DGF management.This clinic was able to successfully reduce hospital length of stay without an increase in 30-d readmission,graft loss,and patient death.