Extended Criteria Donor Kidney Transplantation: Comparative Outcome Analysis Between Single versus Double Kidney Transplantation at 5 Years

Ischemia-Reperfusion Injury in Kidney Transplantation: Mechanisms and Potential Therapeutic Targets

Kidney transplantation offers a longer life expectancy and a better quality of life than dialysis to patients with end-stage kidney disease. Ischemia-reperfusion injury (IRI) is thought to be a cornerstone in delayed or reduced graft function and increases the risk of rejection by triggering the immunogenicity of the organ. IRI is an unavoidable event that happens when the blood supply is temporarily reduced and then restored to an organ. IRI is the result of several biological pathways, such as transcriptional reprogramming, apoptosis and necrosis, innate and adaptive immune responses, and endothelial dysfunction. Tubular cells mostly depend on fatty acid (FA) β-oxidation for energy production since more ATP molecules are yielded per substrate molecule than glucose oxidation. Upon ischemia-reperfusion damage, the innate and adaptive immune system activates to achieve tissue clearance and repair. Several cells, cytokines, enzymes, receptors, and ligands are known to take part in these events. The complement cascade might start even before organ procurement in deceased donors. However, additional experimental and clinical data are required to better understand the pathogenic events that take place during this complex process.

Complement System and the Kidney: Its Role in Renal Diseases, Kidney Transplantation and Renal Cell Carcinoma

The crosstalk among the complement system, immune cells, and mediators of inflammation provides an efficient mechanism to protect the organism against infections and support the repair of damaged tissues. Alterations in this complex machinery play a role in the pathogenesis of different diseases. Core complement proteins C3 and C5, their activation fragments, their receptors, and their regulators have been shown to be active intracellularly as the complosome. The kidney is particularly vulnerable to complement-induced damage, and emerging findings have revealed the role of complement system dysregulation in a wide range of kidney disorders, including glomerulopathies and ischemia-reperfusion injury during kidney transplantation. Different studies have shown that activation of the complement system is an important component of tumorigenesis and its elements have been proved to be present in the TME of various human malignancies. The role of the complement system in renal cell carcinoma (RCC) has been recently explored. Clear cell and papillary RCC upregulate most of the complement genes relative to normal kidney tissue. The aim of this narrative review is to provide novel insights into the role of complement in kidney disorders.

Cancer Stem Cells in Renal Cell Carcinoma: Origins and Biomarkers

The term "cancer stem cell" (CSC) refers to a cancer cell with the following features: clonogenic ability, the expression of stem cell markers, differentiation into cells of different lineages, growth in nonadhesive spheroids, and the in vivo ability to generate serially transplantable tumors that reflect the heterogeneity of primary cancers (tumorigenicity). According to this model, CSCs may arise from normal stem cells, progenitor cells, and/or differentiated cells because of striking genetic/epigenetic mutations or from the fusion of tissue-specific stem cells with circulating bone marrow stem cells (BMSCs). CSCs use signaling pathways similar to those controlling cell fate during early embryogenesis (Notch, Wnt, Hedgehog, bone morphogenetic proteins (BMPs), fibroblast growth factors, leukemia inhibitory factor, and transforming growth factor-β). Recent studies identified a subpopulation of CD133+/CD24+ cells from ccRCC specimens that displayed self-renewal ability and clonogenic multipotency. The development of agents targeting CSC signaling-specific pathways and not only surface proteins may ultimately become of utmost importance for patients with RCC.

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.

Novel Insights into the Molecular Mechanisms of Ischemia/Reperfusion Injury in Kidney Transplantation

Ischemia reperfusion injury (IRI) is one of the most important mechanisms involved in delayed or reduced graft function after kidney transplantation. It is a complex pathophysiological process, followed by a pro-inflammatory response that enhances the immunogenicity of the graft and the risk of acute rejection. Many biologic processes are involved in its development, such as transcriptional reprogramming, the activation of apoptosis and cell death, endothelial dysfunction and the activation of the innate and adaptive immune response. Recent evidence has highlighted the importance of complement activation in IRI cascade, which expresses a pleiotropic action on tubular cells, on vascular cells (pericytes and endothelial cells) and on immune system cells. The effects of IRI in the long term lead to interstitial fibrosis and tubular atrophy, which contribute to chronic graft dysfunction and subsequently graft failure. Furthermore, several metabolic alterations occur upon IRI. Metabolomic analyses of IRI detected a “metabolic profile” of this process, in order to identify novel biomarkers that may potentially be useful for both early diagnosis and monitoring the therapeutic response. The aim of this review is to update the most relevant molecular mechanisms underlying IRI, and also to discuss potential therapeutic targets in future clinical practice.

mTOR inhibition improves mitochondria function/biogenesis and delays cardiovascular aging in kidney transplant recipients with chronic graft dysfunction

CVD remains the major cause of mortality with graft functioning in Kidney transplant recipients (KTRs), with an estimated risk of CV events about 50-fold higher than in the general population. Many strategies have been considered to reduce the CV risk such as the use of mTOR inhibitors. We evaluate whether chronic mTOR inhibition might influence CV aging in KTRs studying the molecular mechanisms involved in this effect. We retrospectively analyzed 210 KTRs with stable graft function on therapy with CNI and mycophenolic acid (Group A, 105 pts.), or with CNI and mTORi (Everolimus, Group B, 105 pts.). The presence of mTOR inhibitor in immunosuppressive therapy was associated to increase serum levels of Klotho with concomitant reduction in FGF-23, with a significant decrease in left ventricular mass. In addition, KTRs with mTORi improved mitochondrial function/biogenesis in PBMC with more efficient oxidative phosphorylation, antioxidant capacity and glutathione peroxidase activity. Finally, group B KTRs presented reduced levels of inflammaging markers such as reduced serum pentraxin-3 and p21ink expression in PBMC. In conclusion, we demonstrated that mTOR inhibition in immunosuppressive protocols prevents the occurrence and signs of CV aging in KTRs.

[Very-old deceased donors in kidney transplantation: How far can we go?]

In order to increase the pool of organ donors, kidney transplantation from very old-donors, notably aged more than 70, is increasing. Compared to the United States, where the use of these grafts does not reach 5%, in France it reaches over 20%. Kidney aging is determined by a progressive glomerusclerosis, interstitial fibrosis, and nephrosclerosis, responsible of a linear decrease of glomerular filtration rate with time. Aging in kidney transplantation goes along also with an increased immunogenicity and risk of ischemia-reperfusion injuries. Hence, the prognosis of these transplantations is worse than those from younger donors, even though it remains better than dialysis. Data is lacking on risk factors of graft loss in this specific population. Hypothermic perfusion machine, pre-implantation kidney biopsy, dual kidney transplantation and immunosuppressive strategies have been evaluated to improve the long-term prognosis of these grafts.

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.

Dual Kidney Transplantation: A Single-Center Experience in Thailand

BACKGROUND

Dual kidney transplants (DKTs) from expanded criteria donors (ECDs) have been performed in our hospital since 2014. We needed to review our clinical outcome and update criteria to selected ECDs for DKTs.

MATERIALS AND METHODS

Between January 2014 and December 2016, 4 DKTs and 269 deceased donor kidney transplants were performed. The outcome of DKTs was reviewed. The literature was reviewed for surgical technique and indication for DKT.

RESULTS

Four DKTs were performed between 2014 and 2016. One-year graft survival rate was 100%. One patient developed delayed graft function. No morbidity or mortality occurred.

CONCLUSIONS

DKTs in our center were safe and had good outcome with optimized selected criteria. DKT can improve the rate of kidney transplant in a developing country.

Increased risk of graft failure and mortality in Dutch recipients receiving an expanded criteria donor kidney transplant

Survival of expanded criteria donor (ECD) kidneys and their recipients has not been thoroughly evaluated in Europe. Therefore, we compared the outcome of ECD and non-ECD kidney transplantations in a Dutch cohort, stratifying by age and diabetes. In all first Dutch kidney transplants in recipients ≥18 years between 1995 and 2005, both relative risks (hazard ratios, HR) and adjusted absolute risk differences (RD) for ECD kidney transplantation were analysed. In 3062 transplantations [recipient age 49.0 (12.8) years; 20% ECD], ECD kidney transplantation was associated with graft failure including death [HR 1.62 (1.44-1.82)]. The adjusted HR was lower in recipients ≥60 years of age [1.32 (1.07-1.63)] than in recipients 40-59 years [1.71 (1.44-2.02) P = 0.12 for comparison with ≥60 years] and recipients 18-39 years [1.92 (1.42-2.62) P = 0.03 for comparison with ≥60 years]. RDs showed a similar pattern. In diabetics, the risks for graft failure and death were higher than in the nondiabetics. ECD kidney grafts have a poorer prognosis than non-ECD grafts, especially in younger recipients (<60 years), and diabetic recipients. Further studies and ethical discussions should reveal whether ECD kidneys should preferentially be allocated to specific subgroups, such as elderly and nondiabetic individuals.

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.

Sequential Bilateral Corneal Transplantation and Graft Survival

PURPOSE

To investigate graft survival and rejection following sequential bilateral corneal transplantation.

DESIGN

Retrospective cohort study.

METHODS

The study included patients with Fuchs endothelial dystrophy (FED), pseudophakic bullous keratopathy (PBK), or keratoconus who had undergone a penetrating keratoplasty (PK), endothelial keratoplasty (EK), or deep anterior lamellar keratoplasty (DALK) between 1999 and 2012. The main cohort included patients who had received a first transplant in both eyes for the same indication and a control cohort patients who had undergone a unilateral first corneal transplant. Main outcome measures were graft rejection or failure at 5 years.

RESULTS

A total of 11 822 patients were included, of whom 9335 had a unilateral and 2487 bilateral corneal transplantation. For patients with FED (P < .005) and KC (P = .03) but not PBK (P = .19), a transplant in the second eye was associated with a 50% reduction in risk of graft failure within 5 years in the first eye (FED: hazard ratio [HR] 0.47, 95% confidence interval [CI]: 0.34-0.64; KC: HR 0.50, 95% CI: 0.24-1.02). For FED this was dependent on the type of transplant (EK: HR 0.30, 95% CI: 0.17-0.52; PK: HR 0.61, 95% CI: 0.42-0.88). We found no association between a transplant in the second eye and a rejection episode in the first eye (KC P = .19, FED P = .39, PBK P = .19).

CONCLUSION

For FED and KC, a transplant in the second eye was associated with a reduced risk of graft failure in the first eye, independent of inter-transplant time. For FED this effect was pronounced following an EK in the first eye, where the risk of failure was reduced by 70%.

Decision Making by Young Transplant Surgeons Regarding Expanded-Criteria Donors With Acute Kidney Injury or Allocation Failure

BACKGROUND

The utilization of expanded-criteria donors (ECDs) has increased to overcome donor shortages. Unfortunately, the discard rate has also increased, especially in ECDs with acute kidney injury (AKI). We evaluated the outcomes of kidney transplantation in ECDs and standard-criteria donors (SCDs) with and without AKI.

METHODS

We reviewed the medical records of patients who underwent kidney transplantation. We used the AKI definition published by the Kidney Disease: Improving Global Outcomes group and reviewed the demographic characteristics of donors and recipients. We analyzed transplantation outcomes.

RESULTS

Twenty-seven patients underwent kidney transplantation from ECDs with AKI (n = 6) or without AKI (n = 5) and SCDs with AKI (n = 6) or without AKI (n = 10). Initial creatinine and estimated glomerular filtration rate (eGFR) were not significantly different between the groups. The incidence of delayed graft function was highest in ECDs with AKI (n = 3; 36.4%), but this was not a significantly difference. There was no difference in the last creatinine and eGFR in ECDs with AKI (1.32 mg/dL, 58.7 mL/min/1.73 m(2)), ECDs without AKI (1.67 mg/dL, 44.2 mL/min/1.73 m(2)), SCDs with AKI (0.94 mg/dL, 81.5 mL/min/1.73 m(2)) and SCDs without AKI (0.97 mg/dL, 81.8 mL/min/1.73 m(2)).

CONCLUSIONS

As the donor pool is extended to ECDs, young transplant surgeons may increasingly face decisions regarding ECDs with AKI or allocation failure. There is no consensus regarding discard criteria. However, if the donor showed initially normal creatinine levels or if dual-kidney transplantation can be performed, young transplant surgeons should not hesitate to use ECDs with AKI or allocation failure.

Comparison of survival outcomes between Expanded Criteria Donor and Standard Criteria Donor kidney transplant recipients: a systematic review and meta-analysis

In 2002, the United Network for Organ Sharing proposed increasing the pool of donor kidneys to include Expanded Criteria Donor (ECD). Outside the USA, the ECD definition remains the one used without questioning whether such a graft allocation criterion is valid worldwide. We performed a meta-analysis to quantify the differences between ECD and Standard Criteria Donor (SCD) transplants. We paid particular attention to select studies in which the methodology was appropriate and we took into consideration the geographical area. Thirty-two publications were included. Only five studies, all from the USA, reported confounder-adjusted hazard ratios comparing the survival outcomes between ECD and SCD kidney transplant recipients. These five studies confirmed that ECD recipients seemed to have poorer prognosis. From 29 studies reporting appropriate survival curves, we estimated the 5-year pooled nonadjusted survivals for ECD and SCD recipients. The relative differences between the two groups were lower in Europe than in North America, particularly for death-censored graft failure. It is of primary importance to propose appropriate studies for external validation of the ECD criteria in non-US kidney transplant recipients.

Digital reporting of whole-slide images is safe and suitable for assessing organ quality in preimplantation renal biopsies

Digital pathology allows networks of "remote" specialist pathologists to report the findings of preimplantation kidney biopsies. We sought to validate the assessment of preimplantation kidney transplant biopsies for diagnostic purposes using whole-slide images according to the recommendations of the College of American Pathologists. Sixty-two consecutive, previously reported, preimplantation kidney biopsies were scanned using the ScanScope Digital Slide Scanner at 0.5 μm/pixel (20× objective). The slides were assessed for percent glomerulosclerosis, tubular atrophy, interstitial fibrosis and vascular narrowing using the Remuzzi criteria by two pathologists, one using glass slides and the other using the whole-slide images viewed on a widescreen computer monitor. After a 2-week washout period, all of the slides were re-assessed by the same pathologists using the opposite mode of reporting to that used in the first evaluation. Very high glass-digital intraobserver concordance was achieved for the overall score and for individual grades by both pathologists (κ range, 0.841-0.973). The overall scores obtained by both pathologists and using both methods were identical. The times needed to assess the biopsies were 14 minutes when using a light microscope and 18 minutes, including scanning time, which averaged 2 minutes 20 seconds per slide, when using digital microscopy. Digital microscopy is a reliable, fast, and safe method for the assessment of preimplantation kidney biopsies.

Dual kidney transplantation: a single-center experience

BACKGROUND

Dual kidney transplantation (DKT) is an alternate approach to use marginal kidneys not suitable to be allocated for single kidney transplant. This retrospective study reviewed the short- and long-term outcomes regarding graft and patient survivals over a 9-year period at a single center.

METHODS

From 2005 to 2013, 33 DKTs were performed in our unit, where allocation was guided by clinical parameters mainly. The mean ages for recipients and donors were 58.6 ± 12.5 and 54.8 ± 13.6 years, respectively. Cold ischemia time was 21.4 ± 4 hours, and mean HLA mismatch for HLA-A, HLA-B, and HLA-DR was 3.06 ± 1.07. Immunosuppression regime was tacrolimus based.

RESULTS

Median follow-up time of 56 months showed patient and death-censored graft survivals at 1, 3, and 5 years to be 90% and 84%, 90% and 81%, and 84% and 81%, respectively. The rate of delayed graft function was 46.9% (n = 15), the rate of primary graft function was 46.9% (n = 15), the rate of and primary graft nonfunction was 6.2% (n = 2). Nineteen patients (59.4%) required biopsy: 12 of them showed acute tubular necrosis and 7 had rejection (1 needed graft removal, 4 were treated successfully with steroid and/or antithymocyte globulin, and 2 did not require treatment).

CONCLUSIONS

Outcomes of DKT in our center were satisfactory and similar to those of other transplant centers regarding patient and graft survivals.

Baseline donor chronic renal injury confers the same transplant survival disadvantage for DCD and DBD kidneys

Histological assessment of baseline chronic kidney injury may discriminate kidneys that are suitable for transplantation, but has not been validated for appraisal of donation after circulatory death (DCD) kidneys. 'Time-zero' biopsies for 371 consecutive, solitary, deceased-donor kidneys transplanted at our center between 2006 and 2010 (65.5% DCD, 34.5% donation after brain death [DBD]) were reviewed and baseline chronic degenerative injury scored using Remuzzi's classification. High scores correlated with donor age and extended criteria donors (42% of donors), but the spectrum of scores was similar for DCD and DBD kidneys. Transplant outcomes for kidneys scoring from 0 to 4 were comparable (1 and 3 year graft survival 95% and 92%), but were much poorer for kidneys scoring ≥5, with 1 year graft survival only 73%, and 12.5% suffering primary nonfunction. Critically, high Remuzzi scores conferred the same survival disadvantage for DCD and DBD kidneys. On multi-variable regression analysis, time-zero biopsy score was the only independent predictor for graft survival, whereas one-year graft estimated glomerular filtration rate (eGFR) correlated with donor age and biopsy score. In conclusion, the relationship between severity of chronic kidney injury and transplant outcome is similar for DCD and DBD kidneys. Kidneys with Remuzzi scores of ≤4 can be implanted singly with acceptable results.

Urine--a waste or the future of regenerative medicine?

In recent years, urine has emerged as a source of urine cells. Two different types of cells can be isolated from urine: urine derived stem cells (USCs) and renal tubular cells called urine cells (UCs). USCs have great differentiation properties and can be potentially used in genitourinary tract regeneration. Within this paper, we attempt to demonstrate that such as easily accessible source of cells, collected during completely non-invasive procedures, can be better utilized. Cells derived from urine can be isolated, stored, and used for the creation of urine stem cell banks. In the future, urine holds great potential to become a main source of cells for tissue engineering and regenerative medicine.

Can only histological evaluation determine the allocation of ECD kidneys?

INTRODUCTION

There is a recent debate on the "transplantability" of ECD (Expanded Criteria Donors) kidneys and the selection criteria used to allocate them to single or double transplantation. Remuzzi et al. have defined a protocol incorporating pre-transplant donor biopsy to guide the use of older donor organs. They allocated organs as single or double transplants on the basis of histological findings. We aim to show the pros and cons of the only histological evaluation in the allocation of ECD kidneys, to compare the different experiences in United States and Europe and thus to discuss whether this tool should be used alone or included in a comprehensive clinical and histopathological evaluation.

DISCUSSION

In the United States many Authors stated that the biopsy actually increases the percentage of kidney discarded and they raised questions about the importance of the biopsy in evaluating ECD kidneys for transplantation. On the other hand, the experiences of the majority of european transplant centers showed that allocating kidneys as single or dual transplant based on biopsy findings may achieve good graft and patient outcomes. Moreover, the experience of some centers as ours showed that kidneys allocated as DKT (Dual Kidney Transplant) on the basis of Remuzzi's score could have been suitable for single transplantation suggesting the need of an adjustment of the Remuzzi Score System. Many Authors, who are in favor of histological evaluation, actually believe that a comprehensive clinical and histopathological assessment before transplantation remains necessary. We lack precise national- or international-based selection criteria to guide clinicians. An adjustment of the Remuzzi Score System could be taken into consideration such as narrowing the indication for DKT from those ECD kidneys with higher scores and including the histological evaluation in a multifactor score.

Emerging urinary markers of renal injury in obstructive nephropathy

The effects of obstruction on renal function are the consequence of many factors that profoundly alter all components of glomerular function. Besides the acute effects on glomerular filtration rate and tubule function, a chronic obstruction induces tubular and interstitial injury that results from the activation of different pathways. The progression of tubulointerstitial injury leads to chronic renal damage characterized by tubular atrophy, inflammatory cell infiltration, and interstitial fibrosis. Obstructive nephropathy is an evolving disease in which the renal damage continues even after relief of the obstruction. In particular, it has been demonstrated that the time of relief is the most important factor in predicting long-term renal function deterioration. In this setting, the EGF/MCP-1 ratio, urinary NGAL, and urinary KIM-1 are useful early biomarkers of progressive renal damage and could have a potential role in predicting the long-term renal outcome. This minireview summarizes the role of these emerging urinary biomarkers of obstructive nephropathy based on the current understanding of the pathophysiology of renal injury.

[Ipsilateral dual kidney transplantation: a monocentric experience about 15 cases and literature review]

OBJECTIVE

Our study aimed to support the viability of the concept of Ipsilateral Dual Kidney Transplantation (DKT) by presenting our initial experience and proposing a review of the literature in this subject.

METHODS

Fifteen ipsilateral DKT were performed at Nice University Hospital between August 2010 and March 2012. We have described our skin incision preferences, the vascular anastomoses, and the uretero-vesical reimplantation. We have analyzed the operative duration, the cold ischemia time (CIT) of both transplants, the blood transfusion volume, the intraoperative and postoperative complications, the time to diuresis recovery, the hospital stay, and the kinetics of the creatinine clearance until the third postoperative month. We have compared our results with those of the literature.

RESULTS

The average CIT of the first transplant (T1) was 17.5 ± 3.3 hours, and that of the second (T2) was 18.4 ± 3.3 hours. The mean operating time was 234 ± 67 minutes. Patients received an average of 2 units of blood during surgery [0-4] and 1.8 units in the postoperative period [0-15]. The complications rate was 26.7% and included an intraoperative T2 artery thrombosis and 3 postoperative complications consistent with a hematoma, a T2 ureteric necrosis and a T2 venous thrombosis. Two transplants were lost (6.7%) and one death (6.7%) was reported on day 40. The average length of hospital stay was 20.9 ± 7.8 days. The mean creatinine clearance values were 12.6 mL/min at D2, 35.6 mL/min at D7, 44.9 mL/min on discharge, and 48.2 mL/min at D90.

CONCLUSION

Our results supported the viability of the dual kidney transplantation concept. Furthermore the ipsilateral approach shortened the procedure and limited the surgical trauma by preserving the contralateral iliac fossa, without compromising renal function recovery or increasing morbidity.

Restored kidney graft from urologist referrals for renal transplantation

BACKGROUND

A new transplantation program using kidneys after a small tumor excision was initiated in Western Australia in February 2007. The aim of this study was to report the outcomes over 5 years.

METHODS

Local urologists were encouraged to refer the kidney to the transplantation service when considering a radical nephrectomy. Recipients are selected according to strict criteria. Between February 2007 and February 2012 24 of 30 referred kidneys were restored for transplantation. Average donor age was 53.4 (range, 32-75) years while the recipients were 66.3 (range, 57-80) years. Twenty-one kidneys were restored after excision of a small tumor (<3.3 cm) and 3 kidneys were restored after being obtained from patients who had experienced complicated ureteric injuries secondary to laparotomy and colectomy.

RESULTS

Nineteen of 24 grafts displayed immediate function, 4 had delayed function, and 1 had nonfunction. The first 3 patients developed urinary leakages, which all resolved by subsequent management. One graft showed a pseudoaneurysm on the day 1 Doppler ultrasound, requiring interventional embolization. All patients but 1 have been off dialysis with satisfactory graft function; creatinine (Cr) levels ranged from 70 μmol/L to 330 μmol/L. There was no tumor recurrence on close follow-up from 6 to 55 months (median, 26). Three patients died due to other medical issues.

CONCLUSION

Kidneys could be restored from urologic disease for transplantation after excision of a small tumor with satisfactory outcomes at an average follow-up of 26 months. Frozen section is necessary to ensure the clearance of the tumor prior to transplantation. A modification of the surgical technique has minimized urine leakage and pseudoaneurysm formation after tumor resection.

Impact of the pre-transplant histological score on 3-year graft outcomes of kidneys from marginal donors: a single-centre study

BACKGROUND

The reliability of kidney biopsy as the sole means for assessing kidneys from extended-criteria donors (ECDs) to be allocated to single or dual transplantation is still a matter of debate.

METHODS

We compared retrospectively 3 years graft survival and renal function in 44 recipients of a single kidney graft from a marginal donor with good renal function and a Karpinski histological score of ≤ 3 and 56 recipients of a single transplant with a Karpinski score of 4 or 5. The donors' and recipients' characteristics were compared by means of Wilcoxon's rank-sum test and Fisher's exact test, and survival was analysed using the log-rank test and Cox regression survival analysis.

RESULTS

The donors with the worse histological scores were slightly younger (68.0 ± 4.74 versus 71.3 ± 4.6 years, P < 0.01) and had a higher glomerular filtration rate (85.8 ± 28.2 versus 76.3 ± 26.53 mL/min, P = 0.013), but there was no difference in serum creatinine levels (0.83 ± 0.24 versus 0.85 ± 0.30 mg/dL, P = 0.381). Three years after transplantation, there was no difference between the two groups in terms of recipient serum creatinine levels (1.94 ± 0.69 versus 1.74 ± 0.49 mg/dL, P = 0.134), estimated glomerular filtration rate (eGFR, 45.6 ± 21.1 versus 51.7 ± 22.0 mL/min, P = 0.331) or the rates of graft loss (27.3 versus 35.7%, P = 0.47), delayed graft function or acute rejection.

CONCLUSIONS

In our experience, provided the donor has a normal renal function, a difference in the pre-transplant histological score of kidneys from marginal cadaveric donors do not have a significant influence on the outcome 3 years after transplantation. Our findings might represent a basis for designing a randomized controlled trial of using a higher histological score threshold for the DKT allocation of grafts from ECDs with a normal renal function.

Long-term results of biopsy-guided selection and allocation of kidneys from older donors in older recipients

In our old-for-old program, we discard or allocate older extended criteria donor kidneys to single (SKT) or dual kidney transplantation (DKT) depending on histological Remuzzi's score in recipients older than 60 years. Here, we analyze the long-term results of this program and try to identify independent predictors of patient and graft survival. Between December 1996 and January 2008, we performed 115 SKT and 88 DKT. Discard rate was 15%. Acute rejection incidence was higher in SKT than in DKT (22.6% vs. 11.4%, p = 0.04). Renal function was better in DKT than in SKT up to 5 years after transplantation. Surgical complications were frequent in DKT. Ten-year cumulative graft survival was significantly lower in the SKT group (31% vs. 53%, p = 0.03). In SKT, histological score 4 provided similar graft survival than 3 or less, whereas in DKT score 4, 5 or 6 displayed similar outcome. Finally, independent predictors of graft survival were history of major adverse cardiac event and 1-year serum creatinine, rather than SKT or DKT. In conclusion, this biopsy-guided old-for-old strategy resulted in acceptable long-term graft survival. Our results suggest that DKT should be considered for scores of 5 or 6 only.

Revisiting double kidney transplantation: two kidneys provide better graft survival than one

Double kidney transplantation is an accepted strategy to increase the donor pool. Regarding older donor kidneys, protocols for deciding to perform a dual or a single transplantation are mainly based on preimplantation biopsies. The aim of our study was to evaluate the long-term graft and patient survivals of our "Dual Kidney Transplant program." Patients who lost one of their grafts peritransplantation were used as controls. A total of 203 patients underwent kidney transplantation from December 1996 to January 2008 in our "old for old" renal transplantation program. We excluded 21 patients because of a nonfunctioning kidney, hyperacute rejection, or patient death with a functioning graft within the first month. Seventy-nine among 182 kidney transplantation the "old for old" program were dual kidney transplantation (DKT). Fifteen of 79 patients lost one of their kidney grafts (the uninephrectomized (UNX) UNX group). At 1 year, renal function was lower and proteinuria greater among the UNX than the DKT group. Patient survival was similar in both groups. However, death-censored graft survival was lower in UNX than DKT patients. The 5-year graft survival rate was 70% in UNX versus 93% in DKT cohorts (P = .04). In conclusion, taking into account the kidney shortage, our results may question whether the excellent transplant outcomes with DKT counter balance the reduced donor pool obviating acceptable transplant outcomes for more patients with single kidney transplantation.