Dual Kidney Transplantation: A Case-Control Comparison With Single Kidney Transplantation From Standard and Expanded Criteria Donors

Mitochondria Transplantation Mitigates Damage in an In Vitro Model of Renal Tubular Injury and in an Ex Vivo Model of DCD Renal Transplantation

OBJECTIVES

To test whether mitochondrial transplantation (MITO) mitigates damage in 2 models of acute kidney injury (AKI).

BACKGROUND

MITO is a process where exogenous isolated mitochondria are taken up by cells. As virtually any morbid clinical condition is characterized by mitochondrial distress, MITO may find a role as a treatment modality in numerous clinical scenarios including AKI.

METHODS

For the in vitro experiments, human proximal tubular cells were damaged and then treated with mitochondria or placebo. For the ex vivo experiments, we developed a non-survival ex vivo porcine model mimicking the donation after cardiac death renal transplantation scenario. One kidney was treated with mitochondria, although the mate organ received placebo, before being perfused at room temperature for 24 hours. Perfusate samples were collected at different time points and analyzed with Raman spectroscopy. Biopsies taken at baseline and 24 hours were analyzed with standard pathology, immunohistochemistry, and RNA sequencing analysis.

RESULTS

In vitro, cells treated with MITO showed higher proliferative capacity and adenosine 5'-triphosphate production, preservation of physiological polarization of the organelles and lower toxicity and reactive oxygen species production. Ex vivo, kidneys treated with MITO shed fewer molecular species, indicating stability. In these kidneys, pathology showed less damage whereas RNAseq analysis showed modulation of genes and pathways most consistent with mitochondrial biogenesis and energy metabolism and downregulation of genes involved in neutrophil recruitment, including IL1A, CXCL8, and PIK3R1.

CONCLUSIONS

MITO mitigates AKI both in vitro and ex vivo.

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.

Endovascular stenting with a drug-eluting stent of transplanted renal artery stenosis in a dual kidney transplanted patient

Renal transplant remains the preferred therapy for end-stage renal disease (ESRD). Given the shortage of suitable donor kidneys, use of an expanded criteria donor (ECD) allows marginal kidneys to be transplanted; albeit at risk of increased graft failure due to lower nephron mass. To reduce the risk of graft failure, double kidney transplant (DKT) is advocated, with favorable outcomes. Transplant renal artery stenosis (TRAS) is one of the most common vascular complications following renal transplant. Unlike single kidney transplants, where TRAS usually presents with fluid overload, uncontrolled hypertension, and worsening kidney functions; it may be clinically silent in DKT patients since they have two functional transplanted kidneys. We hereby report a case of TRAS in a DKT patient who had 2 years of favorable clinical outcomes following successful endovascular stenting. He however recently died of COVID-19 associated pneumonitis.

A neural network for glomerulus classification based on histological images of kidney biopsy

Background

Computer-aided diagnosis (CAD) systems based on medical images could support physicians in the decision-making process. During the last decades, researchers have proposed CAD systems in several medical domains achieving promising results.

CAD systems play an important role in digital pathology supporting pathologists in analyzing biopsy slides by means of standardized and objective workflows. In the proposed work, we designed and tested a novel CAD system module based on image processing techniques and machine learning, whose objective was to classify the condition affecting renal corpuscles (glomeruli) between sclerotic and non-sclerotic. Such discrimination is useful for the biopsy slides evaluation performed by pathologists.

Results

We collected 26 digital slides taken from the kidneys of 19 donors with Periodic Acid-Schiff staining. Expert pathologists have conducted the slides preparation, digital acquisition and glomeruli annotations. Before setting the classifiers, we evaluated several feature extraction techniques from the annotated regions. Then, a feature reduction procedure followed by a shallow artificial neural network allowed discriminating between the glomeruli classes.

We evaluated the workflow considering an independent dataset (i.e., processing images not used in the training procedure). Ten independent runs of the training algorithm, and evaluation, allowed achieving MCC and Accuracy of 0.95 (± 0.01) and 0.99 (standard deviation < 0.00), respectively. We also obtained good precision (0.9844 ± 0.0111) and recall (0.9310 ± 0.0153).

Conclusions

Results on the test set confirm that the proposed workflow is consistent and reliable for the investigated domain, and it can support the clinical practice of discriminating the two classes of glomeruli. Analyses on misclassifications show that the involved images are usually affected by staining artefacts or present partial sections due to slice preparation and staining processes. In clinical practice, however, pathologists discard images showing such artefacts.

Staggered Dual Kidney Transplantation

We describe a case where a patient received a successful dual kidney transplantation in a staggered fashion. Two kidneys from a deceased donor were accepted for 2 separate primary intended recipients, however, due to unforeseen circumstances, both kidneys were eventually transplanted in a staggered fashion into an alternate single recipient. The intention behind this method was to enhance the patient's renal function and to prevent the wastage of a kidney. Despite the significantly prolonged cold ischemia times, the recipient has excellent dual graft function after 3 years. The positive outcome underpins the effectiveness of donor kidneys even with prolonged cold ischemia times outside established best practice guidelines. It also reinforces the effectiveness of dual kidney transplantation. Transplant professionals encounter complex situations occasionally where an established evidence-base or aids to decision-making are limited. This case reflects challenges in decision-making, patient counselling and consent, especially when the opportunity for the staggered dual kidney transplantation, with potential increased morbidity, came about as another recipient declined a usable kidney. It also highlights the widely differing risk appetites of different patients. Crucially, it optimised the donation process and procurement of 2 kidneys while preventing wastage. To our knowledge, this is the first report of a staggered dual kidney transplantation in a single recipient.

Degree of Glomerulosclerosis in Procurement Kidney Biopsies from Marginal Donor Kidneys and Their Implications in Predicting Graft Outcomes

Background: This study aimed to assess the association between the percentage of glomerulosclerosis (GS) in procurement allograft biopsies from high-risk deceased donor and graft outcomes in kidney transplant recipients. Methods: The UNOS database was used to identify deceased-donor kidneys with a kidney donor profile index (KDPI) score > 85% from 2005 to 2014. Deceased donor kidneys were categorized based on the percentage of GS: 0-10%, 11-20%, >20% and no biopsy performed. The outcome included death-censored graft survival, patient survival, rate of delayed graft function, and 1-year acute rejection. Results: Of 22,006 kidneys, 91.2% were biopsied showing 0-10% GS (58.0%), 11-20% GS (13.5%), >20% GS (19.7%); 8.8% were not biopsied. The rate of kidney discard was 48.5%; 33.6% in 0-10% GS, 68.9% in 11-20% GS, and 77.4% in >20% GS. 49.8% of kidneys were discarded in those that were not biopsied. Death-censored graft survival at 5 years was 75.8% for 0-10% GS, 70.9% for >10% GS, and 74.8% for the no biopsy group. Among kidneys with >10% GS, there was no significant difference in death-censored graft survival between 11-20% GS and >20% GS. Recipients with >10% GS had an increased risk of graft failure (HR = 1.27, p < 0.001), compared with 0-10% GS. There was no significant difference in patient survival, acute rejection at 1-year, and delayed graft function between 0% and 10% GS and >10% GS. Conclusion: In >85% KDPI kidneys, our study suggested that discard rates increased with higher percentages of GS, and GS >10% is an independent prognostic factor for graft failure. Due to organ shortage, future studies are needed to identify strategies to use these marginal kidneys safely and improve outcomes.

Dual kidney transplantation offers a safe and effective way to use kidneys from deceased donors older than 70 years

Purpose

Dual kidney transplantation (DKT) offers a way to extend the use of kidneys from expanded criteria donors (ECDs). Here, we compared the outcomes of DKT with those of single kidney transplantation from standard criteria donors (SCDs) and ECDs.

Methods

In 2014, we began performing DKT using both kidneys from deceased donors greater than 70 years of age with one of two risk factors: serum creatinine (sCr) level over 3.0 mg/dl or eGFR under 30 ml/min. By 2017, we had performed 15 DKTs. We compared the outcomes of the 15 DKT recipients with those of 124 patients who received a kidney from an SCD and 80 patients who received a kidney from an ECD.

Results

Compared with ECDs and SCDs, DKT donors were older, had a higher diabetes burden, and a higher sCr level (p < 0.01, < 0.01, and 0.03, respectively). DKT recipients were also older and had a higher diabetes burden than recipients of kidneys from ECDs and SCDs (p < 0.01, both). DKT recipients had a lower nadir sCr and shorter duration to nadir sCr than single ECD KT recipients (p < 0.01and 0.04, respectively).

Conclusions

The survival rates of DKT grafts were compatible with those of single KT grafts. Therefore, DKT may be considered a suitable an option to expand the donor pool.

Outcomes of Deceased Donor Kidney Transplantation Using Expanded Criteria Donor Kidneys Following Pulsatile Preservation

Aim

We compared the outcomes of transplanting expanded criteria donor (ECD) kidneys undergoing machine perfusion (MP) versus cold storage (CS).

Material and methods

Data on all expanded criteria deceased donor kidney transplants performed at the University of Pittsburgh Medical Center from January 2003 through December 2012 were collected from an in-house electronic repository. There were 78 patients in the MP group and 101 patients in the CS group. The majority of the ECD kidneys were imported from other organ procurement organizations: 69 of 73 in the MP group (94.5%, 5 from unknown sources); and 90 of 99 in the CS group (91%), 2 from an unknown source). Most of the patients in the MP group (77 of 78) received a combination of MP and static CS. MP was performed just prior to transplantation in all MP patients. We used descriptive statistics to characterize our sample. We used logistic regression analysis to model the binary outcome of delayed graft function (DGF; i.e., “yes/no”) and Cox (proportional hazard) regression to model time until graft failure. The Kaplan-Meier product-limit method was used to estimate survival curves for graft and patient survival.

Results

A total of 179 transplants were done from ECD donors (MP, 78; CS, 101). The mean static cold storage time was 14 ± 4.1 hours and the mean machine perfusion time was 11.2 ± 6.3 hours in the MP group. The donor creatinine was higher (1.3 ± 0.6 mg/dl vs. 1.2 ± 0.4 mg/dl, p = 0.01) and the cold ischemia time was longer (28.9 ± 10 hours vs. 24 ± 7.9 hours, p = 0.0003) in the MP patients. There were no differences between the two groups in DGF rate (20.8% [MP] vs. 25.8% [CS], p = 0.46), six-year patient survival (74% [MP] vs. 63.2% [CS], p = 0.11), graft survival (64.3% [MP] vs. 51.5% [CS], p = 0.22), and serum creatinine levels (1.5 mg/dl vs. 1.5 mg/dl) on univariate analysis. On unadjusted analysis, MP subjects without DGF had longer graft survival compared to CS subjects with DGF (p < 0.0032) and MP subjects with DGF (p < 0.0005). MP subjects without DGF had longer death-censored graft survival compared to CS subjects with DGF (p < 0.0077) and MP subjects with DGF (p < 0.0016). However, on regression analysis, MP subjects had longer graft survival than CS subjects when DGF was not present. MP subjects without DGF had longer patient survival compared to CS subjects with DGF (p < 0.0289), on unadjusted analysis. MP subjects had a reduced risk of graft failure (hazard ratio [HR], 0.34; 95% confidence interval [CI], 0.17, 0.68) and death-censored graft failure (HR, 0.44; 95% CI, 0.19, 1.00), compared to CS subjects when DGF was not present.

Conclusions

Reduction of DGF rates for imported ECD kidneys is vital to optimize outcomes and increase their utilization. One strategy to decrease DGF rates may be to reduce static CS time during transportation, by utilizing a portable kidney perfusion machine.

A Novel Technique of Dual Kidney Transplantation (DKT) From Adult Donors

OBJECTIVE

To discuss a novel technique of dual kidney transplantation that has not been described in literature.

METHODS

Dual Kidney Transplantation (DKT) is done for kidneys from expanded criteria donors. The 3 described techniques in literature (bilateral placement, unilateral placement with separate or patch anastomosis) have some disadvantages. This newer technique describes the use of the donor iliac artery as an interposition Y graft for joining both kidneys of the dual kidney transplant. This method can overcome some of the disadvantages associated with the previously described techniques. The ureters were implanted in urinary bladder separately in one recipient and together in another recipient.

RESULTS

This technique was used in 2 cases. The cold ischemia time was 275 minutes and 765 minutes, respectively while the operative time was 187 minutes and 192 minutes, respectively in the 2 patients. The first patient has creatinine of 0.83 mg/dl on last follow up at 6 months whereas the other patient has creatinine of 1.12 mg/dl at 3 months follow up. Computed tomography angiography of both the patients revealed good contrast uptake in both kidneys with no stenosis, torsion or lymphocele.

CONCLUSION

The newer technique avoids scarring of both iliac fossa in DKT while reducing operative time and secondary warm ischemia time by doing a single arterial anastomosis in the recipient and allows easier placement of both kidneys in the right iliac fossa.

Dual Kidney Transplantation from Donors at the Extremes of Age

BACKGROUND

The study purpose was to analyze outcomes in recipients of pediatric dual en bloc (PEB) kidneys from small pediatric donors (SPDs, age ≤ 3 years) and dual kidney transplants (KTs) from adult marginal deceased donors (DDs) in the context of the Kidney Donor Profile Index (KDPI).

STUDY DESIGN

This was a single center retrospective review. Recipient selection included primary transplant, low BMI, low immunologic risk, and informed consent. All patients received antibody induction with FK/MPA/± prednisone.

RESULTS

From 2002 to 2015, we performed 34 PEB and 73 adult dual KTs. Mean donor ages were 17 months for the PEB and 59 years for the dual KTs; mean KDPIs were 73% for PEB and 83% for dual KT, and mean cold ischemia times were 21.0 hours for PEB and 26.5 hours for dual KT. Adult dual KT recipients were older (mean age 38 years for PEB and 60 years for dual KT) and had shorter waiting times (mean 25 months for PEB and 12 months for dual KT). With a mean follow-up of 7.6 years, actual patient survival (88% for PEB and 62% for dual KT) and graft survival (71% for PEB and 44% for dual KT) rates were higher in PEB compared with dual KT. Death-censored kidney graft survival rates were 77% for PEB and 58% for dual KT. Delayed graft function (DGF) rates were 15% for PEB and 23% for dual KT; incidences of DGF in single kidney transplantations from SPDs and adult nonmarginal DDs were 20% and 32%, respectively. Based on actual 5-year graft survival rates, the adjusted KDPIs for dual PEB and dual KTs were 3% and 60%, respectively.

CONCLUSIONS

Acceptable mid-term outcomes are associated with PEB and adult dual KTs, which may expand the donor pool and prevent kidney discard. The KDPI is inaccurate for predicting outcomes from either PEB from SPDs or dual KT from adult marginal DDs, which may prevent acceptance of these organs.

Combined Dual-Kidney Liver Transplantation in the United States: A Review of United Network for Organ Sharing/Organ Procurement and Transplantation Network Data Between 2002 and 2012

In kidney-alone recipients, dual-kidney transplantation using "higher-risk" donor organs has shown outcomes comparable to those of single-kidney transplantation using extended criteria donor (ECD) organs. To investigate the feasibility of a similar approach with combined kidney-liver transplantation, we identified 22 dual-kidney liver transplantations (DKLTs) and 3044 single-kidney liver transplantations (SKLTs) performed in the United States between 2002 and 2012 using United Network for Organ Sharing/Organ Procurement and Transplantation Network registry data. We compared donor/recipient characteristics as well as graft/recipient survival between DKLT recipients and SKLT recipients of "higher-risk" kidneys (ECD and high kidney donor profile index [KDPI; >85%] donors). Despite having overall similar donor and recipient characteristics compared with both "higher-risk" donor groups, recipient survival in the DKLT group at 36 months was markedly inferior at 40.9% (compared with 67.5% for ECD SKLT recipients and 64.5% for high-KDPI SKLT recipients); nondeath-censored graft survival did not differ. Death was the most common cause of graft loss in all groups. Contrary to dual-kidney transplantation data in kidney-alone recipients, DKLT recipients in our study had inferior survival when compared with SKLT recipients of "higher-risk" donor kidneys. These findings would suggest that dual kidney-liver transplantation has an uncertain role as a strategy to expand the existing kidney donor pool in combined transplantation.

Dual kidney transplant techniques: A systematic review

BACKGROUND

Dual kidney transplantation (DKT) was developed to improve outcomes from transplantation of extended criteria donors (ECD). This study examined which surgical techniques have been reported for DKT and whether any technique had superior patient and graft survival.

METHOD

Electronic databases were searched for published studies mapping to MESH terms: "kidney or renal" AND "transplan*" AND "dual or double." Single case reports, studies of patients less than 18 years old, studies which did not describe the surgical technique, and studies that did not report patient or graft survival were excluded.

RESULTS

Fifteen reports of 434 DKT recipients were identified. Three techniques were described: bilateral placement; unilateral placement with separate anastomoses; and unilateral placement with patch anastomoses. Patient survival across all three techniques was over 95% at 1 year, and graft survival was also similar at over 90%. Rates of delayed graft function were between 20% and 30% across all techniques.

CONCLUSION

The three techniques have equivalent delayed graft function as well as patient and graft survival rates. This is an encouraging result as it means that the surgeon can choose to use the technique which is most appropriate for their own skills and for the patient.

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.

An Improved Classification of Kidney Function Recovery Using Estimated Glomerular Filtration Rate Slope Post-transplantation

BACKGROUND

The impact of renal function recovery on graft survival was examined using estimated glomerular filtration rate (eGFR) slope after kidney transplantation (GAP classification); this was compared to the conventional classification of immediate graft function (IGF), slow graft function (SGF), and delayed graft function (DGF).

MATERIALS AND METHODS

Overall, 541 cases of cadaveric renal transplants were reviewed from a prospective transplant database. eGFR and its slope were measured using the harmonic mean over the first week post-transplantation. Next, 495 kidney transplant recipients from an independent institution were assessed to determine the prognostic value of graft function based on the eGFR slope.

RESULTS

The main discrimination of eGFR slopes occurred within the first 7 days. Three groups in the GAP classification (Good graft function, Average graft function, Poor graft function) were defined based on eGFR slope tertiles: good graft function (GGF), average graft function (AGF), and poor graft function (PGF) were defined based on the ΔCrCL per day over the first 7 days: <1 mL/min, 1-4 mL/min, and >4 mL/min, respectively. When applied to the validation cohort, the 5-year graft failure was 20% for the PGF group, 4% for the AGF group, and 3% for the GGF group. Multivariable Cox regression analysis demonstrated better prediction of long-term graft function with the new classification (C statistic 0.49 [old)] vs 0.61 [new]).

CONCLUSION

The new GAP criteria were better at predicting long-term graft survival and renal function compared to the conventional classification system, and deserve further consideration in future studies.

Dual kidney transplants from adult marginal donors successfully expand the limited deceased donor organ pool

BACKGROUND

The need to expand the organ donor pool remains a formidable challenge in kidney transplantation (KT). The use of expanded criteria donors (ECDs) represents one approach, but kidney discard rates are high because of concerns regarding overall quality. Dual KT (DKT) may reduce organ discard and optimize the use of kidneys from marginal donors.

STUDY DESIGN

We conducted a single-center retrospective review of outcomes in adult recipients of DKTs from adult marginal deceased donors (DD) defined by limited renal functional capacity. If the calculated creatinine clearance in an adult DD was <65 mL/min, then the kidneys were transplanted as a DKT.

RESULTS

Over 11.5 yr, 72 DKTS were performed including 45 from ECDs, 17 from donation after cardiac death (DCD) donors, and 10 from standard criteria donors (SCD). Mean adult DD and recipient ages were both 60 yr, including 29 DDs and 26 recipients ≥65 yr of age. Mean pre-DKT waiting and dialysis vintage times were 12 months and 25 months, respectively. Actual patient and graft survival rates were 84.7% and 70.8%, respectively, with a mean follow-up of 58 months. One yr and death-censored graft survival rates were 90% and 80%, respectively. Outcomes did not differ by DD category, recipient age, or presence of delayed graft function (DGF). Eleven patients died at a mean of 32 months post-DKT (eight with functioning grafts) and 13 other patients experienced graft losses at a mean of 33 months. The incidence of DGF was 25%; there were two cases (2.8%) of primary non-function. Mean length of initial hospital stay was 7.2 d. Mean serum creatinine and glomerular filtration rate levels at 12 and 24 months were 1.5 and 53 and 1.5 mg/dL and 51 mL/min/1.73 m(2) , respectively. DKT graft survival and function were superior to concurrent single ECD and similar to concurrent SCD KTs. Two patients underwent successful kidney retransplantation, so the dialysis-free rate in surviving patients was 87%. The proportion of total renal function transplanted from adult DD to DKT recipients was 77% compared to 56% for patients receiving single KTs.

CONCLUSIONS

Dual kidney transplantation using kidneys from adult marginal DDs that otherwise might be discarded offer a viable option to counteract the growing shortage of acceptable single kidneys. Excellent medium-term outcomes can be achieved and waiting times can be reduced in a predominantly older recipient population.

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.

Dual kidney transplantation from uncontrolled deceased donors after cardiac arrest: a possible option

Organ shortage is a major problem in organ transplantation. For this reason, transplantation teams have found it necessary to revisit their organ acceptance criteria. Uncontrolled deceased donors after cardiac arrest could increase the donor pool by 20%, but at the same time there is a greater risk of delayed graft function and primary non-function. Dual kidney transplantation is an option when single kidney transplantation cannot be carried out because of lack of organ quality. We report for the first time our four first dual kidney transplantation from uncontrolled deceased donors after cardiac arrest with a follow up longer than 1 year. We described graft outcomes until 5 years, and histology at 3 and 12 months after transplantation. All organs were machine perfused in order to assess their quality leading to a single kidney transplantation or dual kidney transplantation decision. After 1 year of follow up, all grafts were functional with a mean estimated glomerular filtration rate of 44.5 ± 3.3 mL/min/1.73 m(2), and a mean inulin clearance of 43.7 ± 13.6 mL/mn/1.73 m(2). These findings suggest that dual kidney transplantation can represent a viable option for kidneys unsuitable for single kidney transplantation without increasing the rate of surgical complications. Successful transplantation is linked to histological, biological and donor clinical criteria, as well as perfusion parameters.

Adult dual kidney transplantations obtained from marginal donors: two case reports

Organ shortage has led us to use grafts from expanded criteria donors (ECD). Dual kidney transplantation (DKT) using organs from an ECD, which are not acceptable for single kidney transplantation (KT), may overcome the insufficient functioning nephron mass. We performed DKTs in two recipients, the first DKT to be reported from Korea. In case 1, the donor was a 36-year-old man with hypertension. The cause of his brain death was intracranial hemorrhage. He had no known underlying renal disease; his serum creatinine level was 4.2 mg/dL. Despite the relatively young age of the donor, a biopsy revealed mild interstitial fibrosis and tubular atrophy with moderate arteriolar narrowing. The recipient's postoperative course was uneventful over the 69-month follow-up; her last serum creatinine was 1.3 mg/dL. In case 2, the 80-year-old male donor with a history of hypertension had a normal creatinine. The donor biopsy revealed mild glomerular sclerosis, tubular atrophy, and interstitial fibrosis with moderate arteriolar narrowing. The recipient had undergone a previous KT 14 years previously on the right side of the abdomen, but had resumed dialysis 2 years previously due to chronic allograft nephropathy. There was no delayed graft function. At month 4 posttransplantation, lymphoceles were treated by fenestration. At 6-month follow-up, her creatinine was 1.0 mg/dL. In our experience with these two cases, DKT with ECD kidney grafts seemed to be a successful strategy to avoid poor graft outcomes and overcome the donor organ shortage. Further studies including histological criteria for DKT, should be performed to determine the safest means to utilize ECD grafts.

Lessons learned from a single center's experience with 134 donation after cardiac death donor kidney transplants

BACKGROUND

Reports of kidney transplantation from donation after cardiac death (DCD) donors describe high rates of delayed graft function (DGF).

STUDY DESIGN

From April 1, 2003 to October 17, 2010, we performed 134 kidney transplants from DCD donors including 120 (90%) from standard-criteria donors (SCDs) and 14 (10%) from expanded-criteria donors (ECDs). Nineteen kidneys were recovered from donors managed with extracorporeal interval support for organ retrieval (EISOR) after cardiac arrest to minimize ischemic injury.

RESULTS

Comparison of donor and recipient characteristics found no differences for cases managed with or without EISOR. Overall actuarial patient survival rates were 93%, 91%, and 89% at 1, 3, and 5 years, respectively, with a mean follow-up of 31 months. Overall actuarial kidney graft survival rates were 89%, 76%, and 76% at 1, 3, and 5 years, respectively. Actuarial graft survival rates of DCD ECD kidneys were 58% and 48% at 1 and 3 years, compared with 90% and 79% at 1 and 3 years for non-ECD grafts (p = 0.013). DGF occurred in 73 patients (54%) overall and was reduced from 55% to 21% (p = 0.016) with the use of EISOR in locally recovered kidneys. The mean resistance value on machine perfusion and the mean estimated glomerular filtration rate 1 month after transplantation were both improved (p < 0.05) in kidneys from donors managed with EISOR. Mean initial hospital stay was reduced from 8.0 to 5.0 days in patients receiving kidneys recovered with EISOR (p = 0.04).

CONCLUSIONS

EISOR is associated with a lower rate of DGF, lower graft resistance on machine perfusion, and shorter initial hospitalization. Kidneys from DCD SCDs have excellent medium-term outcomes and represent an important means of expanding the donor pool. Kidneys from DCD ECDs have inferior outcomes.

Dual-kidney transplants as an alternative for very marginal donors: long-term follow-up in 63 patients

BACKGROUND

Organ shortage has led to the use of dual-kidney transplant (DKT) of very marginal donors into a single recipient to increase the use of marginal organs. To date, few data are available about the long-term outcome of DKT and its usefulness to increase the pool of available organ.

METHODS

We conducted a single-center cohort study of DKTs with longitudinal follow-up over an 8-year period. Between 1999 and 2007, 63 DKTs were performed. All kidneys from donors younger than 75 years refused by all centers for single transplantation, and kidneys from donors aged 75 years or older were routinely evaluated based on preimplantation glomerulosclerosis. Renal function, patient or graft survival, and perioperative complications were compared with 66 single kidneys from expanded criteria donors (ECD) and 63 ideal kidney donors.

RESULTS

After a median follow-up of 56 months, patient or graft survival was similar between the three groups. Twelve-, 36-, and 84-month creatinine clearance were similar for DKT and ECD (12 months: 58 and 59 mL/min; 36 months: 54 and 60 mL/min; and 84 months: 62 and 51 mL/min, respectively). For the study period, the routine evaluation of very marginal kidneys for DKT in our center has led to an increase of 47% in the transplants from donors aged 50 years or older, which represent 12% at the level of our organ procurement organization.

CONCLUSIONS

DKT patients can expect long-term results comparable with single kidney ECD. The implementation of a DKT program in our unit safely increased the pool of organs from marginal donors.

Elderly Transplant Recipients

While the total number of organs transplanted in this country has increased over the years, there is still an ever-widening gap between the need for organs and our capacity to meet that need as the overall waiting list continues to grow. This is due in part to significant advances in transplant techniques and outcomes such that Americans with organ failure now seek transplants in greater numbers. Additionally, life-expectancy gains in the United States are creating an aging population who are more likely to suffer organ failure than younger Americans. The national transplant waiting list has continued to shift toward older candidates. The Scientific Registry of Transplant Recipients (SRTR) reported that at the end of 2007, 59.7% of all 97,248 candidates on the waiting list for all organs were 50 years old or older, and 14.9% were 65 years or older. These percentages are substantially higher than they were in 1998 (41.5 and 8.1%, respectively) [1].

Donor-estimated GFR as an appropriate criterion for allocation of ECD kidneys into single or dual kidney transplantation

It has been suggested that dual kidney transplantation (DKT) improves outcomes for expanded criteria donor (ECD) kidneys. However, no criteria for allocation to single or dual transplantation have been assessed prospectively. The strategy of DKT remains underused and potentially eligible kidneys are frequently discarded. We prospectively compared 81 DKT and 70 single kidney transplant (SKT) receiving grafts from ECD donors aged >65 years, allocated according to donor estimated glomerular filtration rate (eGFR): DKT if eGFR between 30 and 60 mL/min, SKT if eGFR greater than 60 mL/min. Patient and graft survival were similar in the two groups. In the DKT group, 13/81 patients lost one of their two kidneys due to hemorrhage, arterial or venous thrombosis. Mean eGFR at month 12 was similar in the DKT and SKT groups (47.8 mL/min and 46.4 mL/min, respectively). Simulated allocation of kidneys according to criteria based on day 0 donor parameters such as those described by Remuzzi et al., Andres et al. and UNOS, did not indicate an improvement in 12-month eGFR compared to our allocation based on donor eGFR.