Long-term results with single pediatric donor kidney transplants in adult recipients

A 20-year experience in cadaveric pediatric en bloc kidney transplantation in adult recipients

BACKGROUND AND OBJECTIVES

En bloc kidney transplantation (EBKT) from pediatric donors into adult recipients increases the donor pool. However, this surgical procedure is not widely performed in many transplant centers. To evaluate the long-term outcomes of EBKT from pediatric donors into adult recipients in a single center.

MATERIAL AND METHODS

Retrospective analysis of 42 patients who received pediatric cadaveric EBKT in our center since 1999. Median follow-up period was 73 months (5-233) in which renal function tests were taken and complications registered.

RESULTS

We have performed 42 EBKT from pediatric donors into adult recipients in our center. The recipients' age was 44.1 ± 11.8 years. Pediatric donors were 22.4 ± 14.7 months old and weighted 11.3 ± 3.6 kg. Cold ischemia time was 15.7 ± 4.5 h. During a median follow-up of 73 months, 35 patients (83.3%) had graft survival with excellent function (first-year serum creatinine levels of 0.99 ± 0.25 mg/dl). There were seven graft losses (16.7%) in the immediate postoperative period (four cases of vascular thrombosis, one anastomosis dehiscence and two cortical necrosis).

CONCLUSIONS

The pediatric en bloc renal graft transplantation into adults is a safe technique with excellent medium- to long-term functional performance. The vast majority of significant complications leading to graft loss were reported in the immediate postoperative period. A good selection of donors and recipients as well as an adequate surgical technique are essential to minimize the occurrence of adverse events.

Donor-Recipient BSA Matching Is Prognostically Significant in Solitary and En Bloc Kidney Transplantation From Pediatric Circulatory Death Donors

Background.

As the rate of early postoperative complications decline after transplant with pediatric donation after circulatory death (DCD) kidneys, attention has shifted to the long-term consequences of donor–recipient (D-R) size disparity given the pernicious systemic effects of inadequate functional nephron mass.

Methods.

We conducted a retrospective cohort study using Organ Procurement and Transplantation Network data for all adult (aged ≥18 y) recipients of pediatric (aged 0–17 y) DCD kidneys in the United States from January 1, 2004 to March 10, 2020.

Results.

DCD pediatric allografts transplanted between D-R pairs with a body surface area (BSA) ratio of 0.10–0.70 carried an increased risk of all-cause graft failure (relative risk [RR], 1.36; 95% confidence interval [CI], 1.10–1.69) and patient death (RR, 1.32; 95% CI, 1.01–1.73) when compared with pairings with a ratio of >0.91. Conversely, similar graft and patient survivals were demonstrated among the >0.70–0.91 and >0.91 cohorts. Furthermore, we found no difference in death-censored graft survival between all groups. Survival analysis revealed improved 10-y patient survival in recipients of en bloc allografts (P = 0.02) compared with recipients of single kidneys with D-R BSA ratios of 0.10–0.70. A similar survival advantage was demonstrated in recipients of solitary allografts with D-R BSA ratios >0.70 compared with the 0.10–0.70 cohort (P = 0.02).

Conclusions.

Inferior patient survival is likely associated with systemic sequelae of insufficient renal functional capacity in size-disparate DCD kidney recipients, which can be overcome by appropriate BSA matching or en bloc transplantation. We therefore suggest that in DCD kidney transplantation, D-R BSA ratios of 0.10–0.70 serve as criteria for en bloc allocation or alternative recipient selection to optimize the D-R BSA ratio to >0.70.

Kidney transplantation outcomes for adult recipients of pediatric donor kidneys

Despite a paucity of data assessing transplantation of deceased-donor pediatric donor kidneys into adult recipients, utilization of pediatric organs is declining in the UK, likely due to concerns that such organs may have inferior outcomes. However, we hypothesized that these concerns may be unfounded. As such, the aim of the study was to compare kidney transplant outcomes between adult recipients of pediatric and adult deceased-donor organs. Data were collected from the UK Transplant Registry for all adult (18+ years) deceased-donor single-kidney transplant recipients between January 2000 and January 2016. Univariable and multivariable analyses were undertaken, to compare a range of outcomes between recipients of kidneys from pediatric and adult donors. Transplants were stratified by the donor age (years) as follows: 0-16 (n = 666), 17-18 (n = 465), and 19-44 (n = 7378). Recipients of pediatric donor kidneys were observed to have improved long-term graft function, with a median creatinine at 1 year of 109 vs. 117 μmol/L for recipients of donors aged 0-16 vs. 19-44 years (P < .001). However, on multivariable analysis, this was not found to correspond to a significant difference in patient (P = .914) or graft survival (P = .190) between the donor age groups. Subgroup analysis within the younger donors found no significant differences in recipient outcomes between donors aged 0-6, 7-12, and 13-16 years. In this population cohort study, we identified excellent outcomes among adult recipients of pediatric donor kidneys. Pediatric donors are a valuable source of organs for adult recipients in an era where organ demand is rising.

Pediatric Donor Glomerulopathy Is a Possible Cause of Abnormal Urinalysis in Adults Receiving Small Pediatric Donor Kidneys

Background.

Reports about prognosis of adults receiving small pediatric-donor kidneys (PDK) as compared to those receiving elder pediatric or adult donor kidneys (ADKs) are controversial. This study aimed to examine the outcomes of adults receiving small PDK and possible prognostic factors.

Methods.

The records of adults who received kidneys from donors < 10 years old at our center from July 1, 2011 to June 30, 2018 were reviewed.

Results.

A total of 121 adults were small PDK recipients. Twenty-three patients received 29 biopsies or nephrectomy between 6 and 896 days posttransplantation days. Seven patients (30.4%) had pediatric donor glomerulopathy (PDG), which developed from 113 to 615 days posttransplantation. The incidence of proteinuria and hematuria was significantly higher in the PDG group. The characteristic pathological finding in PDG was irregular lamination and splintering of the glomerular basement membrane (GBM). Donor age, donor weight, and donor kidney volume were significantly less in PDG cases compared with the non-PDG cases. For the risk factors of PDG, increasing urinary RBC count during follow-up was an independent predictor, while increasing donor age and body weight were protective factors. PDG was not a significant risk factor for Scr increasing of PDKs.

Conclusions.

PDG is a potential cause of abnormal urinalysis in adults receiving small PDKs. The pathological characteristic change of PDG is splitting and lamination of GBM. Persistent hematuria after transplantation in recipients of PDK is a predictor of PDG development.

Successful Single-kidney Transplantation in Adult Recipients Using Pediatric Donors Aged 8 to 36 Months: Comparable Outcomes With Those Using Pediatric Donors Aged >3 Years

BACKGROUND

Using pediatric donors for single-kidney transplantation (SKT) can increase the number of possible recipients. However, it is unclear when SKT involving small pediatric donors and adult recipients can safely be performed without compromising graft outcome.

METHODS

From 2013 to 2017, a total of 102 SKTs in adult recipients were performed in our center using pediatric donors aged <12 years. We compared the outcomes from donors aged 8 to 36 months (the small-kidney group [SKG], n = 46) and from donors aged 3 to 12 years (the big-kidney group [BKG], n = 56). The median follow-up time was 30 months in the SKG and 28 months in the BKG.

RESULTS

All patients achieved satisfactory renal function after transplantation, despite the fact that some patients (SKG, 19.6%; BKG, 28.6%) developed delayed graft function. One-year graft survival and death-censored graft survival in the SKG were 89.1% and 100%, respectively, comparable to the results in the BKG (92.9% and 98.2%). One year later, the graft and patient survival rates in both groups remained unchanged. Pulmonary infection was the main cause of death in patients with a functioning graft (SKG, 4 patients; BKG, 2 patients). Proteinuria occurred early in some patients (SKG, 30.4%; BKG, 19.6%) and decreased gradually within the first year posttransplantation.

CONCLUSIONS

SKT from pediatric donors aged 8 to 36 months to selected adult recipients produced excellent intermediate-term outcomes, comparable with those when older pediatric donors were used. This study provides evidence to support a lower age limit for SKT from pediatric donors.

Small Split Pediatric Kidneys to Expand the Donor Pool: An Analysis of Scientific Registry of Transplant Recipients (SRTR) Data

BACKGROUND

Increased use of pediatric deceased donor kidneys could enlarge the deceased donor kidney pool. Kidney transplant outcomes from small pediatric donors were compared with those from ideal kidney (IK) and expanded criteria kidney (ECK) donors to understand the optimal use of pediatric donor kidneys.

METHODS

Kaplan-Meier analyses compared long-term patient and death-censored graft survival of en bloc kidney (EBK) and split kidney (SpK) transplants from small pediatric donors (aged ≤8 y and weight <30 kg) with those from IK and ECK. Posttransplant serum creatinine) was compared among these cohorts. Deceased donor kidney disposition was determined from small pediatric donors with ≥1 organ transplanted.

RESULTS

Patient and death-censored graft survival were similar among recipients of IK, EBK, and SpK transplants, and were superior to those of recipients of ECK. EBK and SpK transplants from donors 5-30 kg had first-year graft loss similar to ECK. Long-term graft survival and serum creatinine with kidneys from SpK donors >10 kg were better than that with ECK donors. About 3901 transplants were performed from 3660 pediatric donors (53% yield).

CONCLUSIONS

Pediatric kidneys can augment the kidney donor pool and should not be considered ECK. If 90% of kidneys from donors (aged ≤8 y and weight <30 kg) with ≥1 organ transplanted been used (as SpK when >10 kg) an additional 159 kidney transplants per year could have been performed. Expanding the use of pediatric kidneys should be further explored by the transplant community.

The temporal and long-term impact of donor body mass index on recipient outcomes after kidney transplantation - a retrospective study

The impact of increasing body mass index (BMI) on development and progression of chronic kidney disease is established. Even implantation kidney biopsies from obese living donors demonstrate subtle histologic changes despite normal function. We hypothesized that kidneys from obese living (LD) and deceased donors (DD) would have inferior long-term allograft outcomes. In a study utilizing US transplant registry, we studied adult kidney transplant recipients from 2000 to 2014. Donors were categorized as BMI <20 (underweight), 20-25 (normal), 25-30 (overweight), 30-35 (mildly obese), and >35 kg/m² (very obese). Our outcome of interest was death censored graft failure (DCGF). Cox proportional hazards model were fitted separately for recipients of DD and LD kidneys, and adjusted for donor, recipient, and transplant characteristics, including donor and recipient size mismatch ratio. Among 118 734 DD and 84 377 LD transplants recipients, we observed a significant and graded increase in DCGF risk among the overweight (LD:HR = 1.06, DD:HR = 1.04), mildly obese (LD:HR = 1.16, DD:HR = 1.10), and very obese (LD:HR = 1.22, DD:HR = 1.22) compared to normal BMI (P < 0.05). The graded effect of donor BMI on outcomes begins early and persists throughout the post-transplant period. Donor obesity status is an independent risk factor for inferior long-term renal allograft outcome despite adjusting for donor and recipient size mismatch and other donor, recipient, and transplant factors.

Is donor age 6 years or less related to increased risk of surgical complications in pediatric kidney transplantation?

INTRODUCTION

Despite the widespread organ shortage dilemma, there is hesitancy regarding utilization of young donors (aged ≤6 years) because previous reports have suggested that this is associated with an increased risk of surgical complications and graft loss.

OBJECTIVE

The aim of this study was to determine if donor age ≤6 years is related to increased risk of surgical complications or allograft loss in pediatric kidney transplantation (KT).

STUDY DESIGN

A retrospective study of pediatric kidney transplants (KT) undertaken between January 2000 and July 2015. The incidence of surgical and urological complications, and allograft loss were analyzed and compared between donors aged ≤6 years (Group 1) and donors aged >6 years (Group 2).

RESULTS

A total of 171 pediatric KTs were performed at the current center during the study period. Twenty-eight patients were excluded; as a result, the study comprised 143 patients: 60 (Group 1) and 83 (Group 2). Mean recipient weight was 17 kg (SD 9.7; range 3.2-47) in Group 1 and 38.2 kg (SD 15.3; range 7.8-73) in Group 2. Despite a significantly higher proportion of risk factors in Group 1, no significant between-group differences were observed in terms of: surgical complications (OR 0.4; range 0.1-1.2), early urological complications (OR 2.2; range 0.4-11), late urological complications (OR 0.3; range 0.8-1.4), lymphoceles (OR 6.2; range 0.7-51.7) and allograft loss (OR 1.5; range 0.7-3.1, summary Table). Graft survival at 1 and 5 years was: 81% and 70% (Group 1) and 92% and 79% (Group 2), respectively (P = 0.093). Mean follow-up was 90.13 ± 49.7 months.

DISCUSSION

The main finding of this retrospective study was that pediatric donor kidneys from donors aged ≤6 years could safely be used in pediatric recipients without an increased risk of surgical and urological complications or graft loss. Nevertheless, KT with small donor kidneys is challenging and should be performed at experienced pediatric centers.

CONCLUSION

In line with these results, the outcomes of KT using donors aged ≤6 years were encouraging and similar to those obtained with older donors. Thus, this study supported using kidney grafts from young donors, given the organ shortage and potential high mortality risk while awaiting KT.

Graft Growth and Podocyte Dedifferentiation in Donor-Recipient Size Mismatch Kidney Transplants

Background

Kidney transplantation is the treatment choice for patients with end-stage renal diseases. Because of good long-term outcome, pediatric kidney grafts are also accepted for transplantation in adult recipients despite a significant mismatch in body size and age between donor and recipient. These grafts show a remarkable ability of adaptation to the recipient body and increase in size in a very short period, presumably as an adaptation to hyperfiltration.

Methods

We investigated renal graft growth as well as glomerular proliferation and differentiation markers Kiel-67, paired box gene 2 and Wilms tumor protein (WT1) expression in control biopsies from different transplant constellations: infant donor for infant recipient, infant donor for child recipient, infant donor for adult recipient, child donor for child recipient, child donor for adult recipient, and adult donor for an adult recipient.

Results

We detected a significant increase in kidney graft size after transplantation in all conditions with a body size mismatch, which was most prominent when an infant donated for a child. Podocyte WT1 expression was comparable in different transplant conditions, whereas a significant increase in WT1 expression could be detected in parietal epithelial cells, when a kidney graft from a child was transplanted into an adult. In kidney grafts that were relatively small for the recipients, we could detect reexpression of podocyte paired box gene 2. Moreover, the proliferation marker Kiel-67 was expressed in glomerular cells in grafts that increased in size after transplantation.

Conclusions

Kidney grafts rapidly adapt to the recipient size after transplantation if they are transplanted in a body size mismatch constellation. The increase in transplant size is accompanied by an upregulation of proliferation and dedifferentiation markers in podocytes. The different examined conditions exclude hormonal factors as the key trigger for this growth so that most likely hyperfiltration is the key trigger inducing the rapid growth response.

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 to the 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/dL vs 0.49 mg/dL, 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/dL vs 1.35 mg/dL and 72.5 mL/min per 1.73 m²vs 60.5 mL/min per 1.73 m² (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.

Optimizing recovery, utilization and transplantation outcomes for kidneys from small, ≤20 kg, pediatric donors

The optimal balance between maximizing the number versus the outcome of transplantation utilizing kidneys from small (≤20 kg) pediatric donors remains unclear, complicated by the choice of single versus en bloc transplantation with their attendant technical risks. Using the Organ Procurement and Transplantation Network (OPTN) database, we examined kidney recovery and utilization patterns, and 1-year transplant outcomes by single kilogram weight strata. Between January 1, 2005 and June 30, 2010, 2352 kidneys from ≤20 kg donors were transplanted into 1531 recipients, 710 single kidney transplants (SKTs) and 821 en bloc kidney transplants (EBKTs). Increased donor weight was associated with higher rates of recovery, transplantation and SKT. Low donor weight (linear p < 0.001; quadratic p = 0.003), SKT versus EBKT (p = 0.008), increased cold ischemia time (p = 0.003), local versus nonlocal donor (p = 0.0044), low versus high volume center (p = 0.003) and the interaction term between center volume and donor weight (p = 0.0024) were associated with graft failure. Notably, lower donor weight exacerbated the negative impact of low center volume but did not worsen the negative impact of SKT on outcomes. Our data show that EBKT offers superior 1-year survival at the expense of accomplishing one rather than two transplants. However, SKTs yield excellent outcomes when performed at experienced centers.

En bloc kidney transplant from an 18-month-old donor to an adult recipient: Case report and literature review

INTRODUCTION

There is an ever-increasing need for organ donations globally. Paediatric kidney transplantation into adult recipients is a well-recognised technique to expand the donor pool. The transplantation can be done either via en bloc kidney transplant (EBKT) or as single kidney transplantation (SKT).

PRESENTATION OF CASE

An EKBT from a 18-month-old (15 kg) male patient was transplanted in a 35-year old, 85 kg male with end stage renal failure (ESRF), secondary to Focal Segmental Glomerulosclerosis (FSGS) on haemodialysis. Post-operative recovery was uneventful. Immuno-suppressant drugs used were tacrolimus, basiliximab and prednisolone. Doppler ultrasound scans performed post-operatively showed normal renal resistive indices in both kidneys. Serum creatinine decreased from 1200 to 170 μmol/L 57 with eGFR improving from 4 to 38 mL/min/1.73 m² at four weeks post-transplant.

DISCUSSION

Given the low incidence of paediatric donors, EBKTs are relatively uncommon and subsequently published series tend to be centre specific with small numbers. The graft survival rates tell us that paediatric kidney donors should not be considered as marginal transplants. The difficulty is in determining when it is more appropriate to perform a paediatric EBKT as opposed to splitting and performing two SKT. Unfortunately there are no widely accepted guidelines to direct clinicians.

CONCLUSION

This case report highlights the first EKBT performed at our institution. The current literature demonstrates that paediatric donors are excellent resources that should be procured whenever available.

Single pediatric kidney transplantation in adult recipients: comparable outcomes with standard-criteria deceased-donor kidney transplantation

BACKGROUND

Single pediatric kidney transplantation (SKT) in adult recipients has traditionally been considered a high risk because of concerns of technical complications leading to poor graft outcomes. The primary goal of this single-center, retrospective analysis was to compare outcomes after SKT to standard-criteria deceased-donor kidney transplantation (SCDKT).

METHODS

We compared outcomes in adult recipients after SKT (n=31; mean donor weight, 27 kg); SCDKT (n=283); pediatric en bloc (n=21), living-donor (n=275), and extended criteria-donor (n=100) kidney transplantations.

RESULTS

The death-censored 5-year graft survival after SKT was significantly superior to SCDKT (81.4% vs. 74.5%, P=0.02). The serum creatinine level at 5 years after transplantation was significantly lower in SKT compared with that in SCDKT (1.2 vs. 1.6 mg/dL, P<0.0001). There was a significantly higher incidence of arterial anastomotic stenosis (6.8% vs. 0.4%, P=0.02) and hydronephrosis (12.9% vs. 5.3%, P=0.02) in the SKT cohort compared with SCDKT. Subgroup analysis of the SKT cohort by donor age less than 5 years vs. 6 to 10 years (mean weight, 16.4 vs. 32.7 kg) revealed no differences in patient or graft survival.

CONCLUSIONS

Despite a higher incidence of posttransplantation vascular and urological complications, long-term graft survival after SKT (in weight-matched pediatric donors and selected adult recipients) was comparable with that after SCDKT. SKT from very small donors (age, ≤5 years) yielded excellent long-term patient and graft survivals. The use of pediatric donor kidneys should be encouraged to address the problem of organ shortage.

Intermediate-term outcome of single kidney grafts from pediatric donors weighing 10-14 kg in adult recipients

BACKGROUND

Kidneys from pediatric donors weighing <10 kg are preferably transplanted en bloc, while kidneys from donors weighing >15 kg can be safely transplanted as single kidneys. However, single kidney transplantation from donors weighing 10-14 kg is controversial and has not been well investigated.

METHODS

We analyzed the outcome of 15 recipients of single kidneys from donors weighing 10-14 kg (study group) with 40 recipients receiving an allograft from ideal deceased donors (control group).

RESULTS

After a follow-up of three yr, death-censored graft survival was 100% in both groups. The calculated creatinine clearance was lower in the study group at six months (53 vs. 71 mL/min; p = 0.01) and similar at 12 months (68 vs. 68 mL/min; p = 0.48), 24 months (81 vs. 70 mL/min; p = 0.58), and 36 months (74 vs. 69 mL/min; p = 0.59). Urinary albumin/creatinine ratios were comparable between the two groups up to two yr. At three yr, urinary albumin/creatinine ratios were higher in the study group than the control group (10.5 vs. 0.9 mg/mmol; p = 0.007). Surveillance biopsies at three and six months post-transplant revealed no evidence for focal segmental glomerulosclerosis in the study group.

CONCLUSIONS

Transplantation of single pediatric kidneys from donors weighing 10-14 kg into adult recipients provides excellent intermediate-term outcomes. Low-grade albuminuria, three yr post-transplant, might indicate late-onset hyperfiltration injury.

Early inhibition of the renin-angiotensin system improves the long-term graft survival of single pediatric donor kidneys transplanted in adult recipients

Transplanting single pediatric donor kidneys into adult recipients has an increased risk of hyperfiltration injury and graft loss. It is unknown if renin-angiotensin system (RAS) blockers are beneficial in this setting. We retrospectively analyzed 94 adults who received single kidneys from donors <10 years old during 1996-2009. The recipients were divided into group 1 with RAS blockers (n = 40) and group 2 without RAS blockers (n = 54) in the first year of transplant. There was no significant difference in any donor/recipient demographic between the two groups. Graft function, incidence of delayed graft function, acute rejection, and persistent proteinuria were not statistically different either. Kaplan-Meier estimated death-censored graft survivals were significantly better in group 1 than in group 2: 95 vs. 81.2%, 82.4 vs. 61.2%, 72.6 vs. 58.5%, and 68.5 vs. 47.2% at 1, 3, 5, and 7 years, respectively (log rank P = 0.043). Multivariable analysis found persistent proteinuria was a risk factor for graft loss (OR 2.70, 95% CI 1.33-5.49, P = 0.006), while RAS blockers reduced the risk of graft loss (OR 0.38, 95% CI 0.18-0.79, P = 0.009). Early RAS blockade therapy in the first year of transplant is associated with superior long-term graft survival among adults transplanted with single pediatric donor kidneys.

Pediatric en bloc kidney transplantation into pediatric recipients: the French experience

Chronic shortage of available donor organs has led to re-evaluation of the use of en bloc kidney transplants. Although excellent results have been reported in adult patients, experience in pediatric patients remains limited because of potential early complications and poor long-term graft outcome. We report 14 pediatric en bloc renal transplantations into 14 pediatric recipients, performed between 1990 and 2007 in France. We retrospectively analyzed demographic data, postoperative complications, and graft function with a median follow-up of five yr. Donor age ranged from four to 54 months. Complications were vascular graft thrombosis in four patients, leading to graft loss in two cases, and to excellent long-term graft function in the two others. Two hemorrhagic complications resulted in death in one case and in graft loss in the other. Six acute rejection episodes occurred in four patients. Median glomerular filtration rate at three months, one, five, and 10 yr was 90.8, 106, 87.8, and 66.1 mL/1.73 m(2) /min. We believe that en bloc transplantation may be an option for children with end-stage kidney disease.

Pediatric en bloc kidney transplantation to adult recipients: more than suboptimal?

BACKGROUND

To optimize available organs, kidneys from young donors traditionally believed to be suboptimal are transplanted to adults. The purpose of this study is to compare graft survival (GS) of en bloc kidney (EBK) from young pediatric donors to other deceased donor transplants in adult recipients.

METHODS

We analyzed United Network of Organ Sharing/STAR data on primary deceased donor kidney transplants to adult recipients (1988-2006). EBK (age younger than 5 years, n=1696) was compared with solitary pediatric (SP; age younger than 5 years) kidneys (n=1502), and matched standard adult donors (age 18-59 years, n=9594) and expanded criteria donor (ECD; n=6396). The adjusted GS was obtained using Cox proportional hazard model and hazard ratios were calculated.

RESULTS

EBK had lowest acute rejection rates (6.0%) but similar to standard adult transplants (6.3%), and lower than SP and ECD (9.0% and 8.2%; P<0.0001). Delayed graft function rates were lowest in EBK (17.9%), highest in ECD (34.8%; P<0.0001), and similar among SP and standard adult transplants (24.4% and 24.2%). The estimated glomerular filtration rate (eGFR) was best in EBK and worst in ECD (P<0.0001). The eGFR of EBK and SP transplants continuously improved but the eGFR of standard adult and ECD declined. Graft loss was higher in EBK and SP transplants than adult donor transplants during the first 6 months. Despite the highest thrombosis rates in EBK (5.0%) (SP, 3.3%; standard adult, 1.8%; ECD, 2.0%, P<0.0001), GS of EBK became similar to standard adult donor transplants by 5 years and best at 10 years posttransplant (64.0%) and worst in ECD (39.6%; P<0.0001).

CONCLUSION

EBK had the best long-term outcomes among deceased donor transplants and offer unique options for adult kidney transplant recipients.

Pediatric en bloc kidney transplantation into pediatric recipients

As a result of the ongoing shortage in organ supply, en bloc renal transplantation from small donors has become more common for adult recipients with ESRD. However, because of concern for higher complication rates and sub-optimal outcomes, it is not being performed in every center, and data describing its use in pediatric recipients are even more limited. We retrospectively studied three patients who have undergone en bloc renal transplantation at our center. Median age at transplantation was 16.7 yr with a median follow-up of 1.2 yr. Donor age ranged from nine to 49 months with weight ranging from 10 to 22 kg. There were no post-operative thrombotic complications. All grafts showed increased renal size at follow-up by ultrasound. There was no clinical or histological rejection at last follow-up. To the best of our knowledge, this is the first report on the outcomes of en bloc kidney transplantation from pediatric donors into pediatric recipients. Based on our experience, albeit very limited, we feel that en bloc renal transplantation from young donors is an acceptable and safe procedure with low complication rates in pediatric recipients and should be given consideration to minimize wait times on the wait list and to improve quality of life.

Single kidney transplantation from young pediatric donors in the United States

Kidney transplantation (KTX) from small pediatric donors is performed as single or en bloc. Criteria to determine when to split pediatric donor kidneys and transplant as singles are not well established. Data reported to the Scientific Registry of Transplant Recipient for donors <10 yrs from 1995 to 2007 were reviewed (n = 5079). Donors were categorized by weight group by 5 kg increments and solitary (n = 3503) versus en bloc (n = 1576). The primary outcome was overall graft survival. Results were compared as adjusted hazard ratios (aHR) relative to ideal standard criteria donors (SCDs) (defined as age 18-39 without other risk factors), non-ideal SCDs (all other SCDs) and expanded criteria donors (age 50-59 with other risk factors or age >or=60). Single KTX from donors >or= 35 kg conferred a similar risk of graft survival as ideal SCDs. Of donors 10-34 kg, risks of en bloc KTX were similar to ideal and risks of single KTX to non-ideal SCDs; single and en bloc KTXs had 7.9 and 5.2 graft losses per 100 follow-up years, respectively. Single KTX from donors >35 kg are similar to ideal SCDs. Single KTX from donors 10-35 kg are similar to non-ideal SCDs. From a resource perspective, pediatric donors 10-35 kg used as singles offer more cumulative graft years than when used en bloc.

Long-term outcome of adults who undergo transplantation with single pediatric kidneys: how young is too young?

BACKGROUND AND OBJECTIVES

The optimal donor age for transplanting a single pediatric kidney in an adult recipient remains unknown. En block kidney transplantation is usually performed when the donor age is <5 yr.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We compared the outcomes of adult patients who underwent transplantation with single pediatric kidneys from donors who were younger than 5 yr (group 1, n = 40) and from donors who were aged 5 to 10 yr of age (group 2, n = 39) in our center.

RESULTS

The donor kidney sizes were significantly smaller in group 1 than in group 2 (P < 0.001), and group 1 required more ureteral stents than group 2 (73 versus 38%). The surgical complications, delayed graft function, and development of proteinuria were similar in both groups. Group 1 had slightly higher rejection episodes than group 2 (25 versus 18%; P = 0.67), and graft function was comparable in both groups. There were no statistical differences between the two groups in patient (P = 0.73) or death-censored graft (P = 0.68) survivals over 5 yr.

CONCLUSIONS

Single pediatric kidney transplants from donors who are younger than 5 yr can be used with acceptable complications and long-term outcomes as those from older donors.

Kidney transplantation and donation in children

It has been shown that kidney transplantation results in superior life expectancy and quality of life compared with dialysis treatment for patients with end-stage renal disease. However, kidney transplantation in children differs in many aspects from adult kidney transplantation. This review focuses on specific issues of surgical care associated with kidney transplantation in children, including timing of transplantation, technical considerations, patient and graft survival, growth retardation and post-transplant malignancy. At the same time, there is a large discrepancy between the number of available donor kidneys and the number of patients on the waiting list for kidney transplantation. There is a general reluctance to use paediatric donor kidneys, because of relatively frequent complications such as graft thrombosis and early graft failure. We review the specific aspects of kidney transplantation from paediatric donors such as the incidence of graft thrombosis, hyperfiltration injury and 'en bloc' transplantation of two kidneys from one donor with an excellent long-term outcome, which is comparable with adult donor kidney transplantation. We also discuss the potential use of paediatric non-heart-beating donor kidneys, from donors whose heart stopped beating with the preservation techniques used.

Recovery factors affecting utilization of small pediatric donor kidneys

Kidneys from small pediatric donors are underutilized. Using data from the Scientific Registry of Transplant Recipients for donors <21 kg in which at least one organ was recovered from 1997 to 2007 (n = 3341), donor and recovery factors were evaluated by multivariate analysis for associations with (a) kidney nonrecovery and (b) transplantation of recovered kidneys.

RESULTS

The proportion of kidney recoveries were 55% during liver procurements and 40% during intestine procurements amongst donors <10 kg (p < 0.01) compared to 93% and 88%, respectively, for donors weighing 10-20 kg (p = 0.003). Intestine procurement was independently associated with an 81% greater likelihood of kidney nonrecovery (p < 0.0001) and a 48% lower likelihood of transplantation (p = 0.0004). A multivariate Cox model indicated that single kidney recipients had a 63% higher risk of graft failure compared with en bloc kidney recipients (p < 0.0001); however, concurrent intestine recovery was not a significant risk factor for graft loss. Intestine recovery from donors <21 kg of age is strongly associated with higher kidney nonrecovery and lower transplantation rates. Graft survival is worse with single kidney transplantation, but is not significantly affected by intestine recovery. Small pediatric donors procurement teams should strive to increase kidney recoveries overall and en bloc recoveries in particular.

Single versus en bloc kidney transplantation from pediatric donors less than or equal to 15 kg

BACKGROUND

Kidney transplantation from small pediatric donors is being performed with increased frequency as single (SK) or en bloc (EBK) kidneys.

METHODS

Between 2002 and 2006, 19 EBK and 14 SK transplants from pediatric donors less than or equal to 15 kg were performed. SK arterial anastomoses were performed to the aortic patch (n=8), aortic conduit (n=1), or renal artery orifice (n=5).

RESULTS

En bloc kidney donors were on average younger (12+/-10 vs. 24+/-8 months, respectively; P=0.0102) and weighed less (10+/-3 vs. 13+/-3, respectively; P=0.0184). There were no differences between the two groups in recipient age, race, body mass index, degree of sensitization, retransplantation, and cold ischemia time; however, EBK recipients were somewhat better matched at the human leukocyte antigen DR locus (P=0.0515). Delayed graft function was more frequent in the SK group (25% vs. 0%; P=0.0542). Acute rejection occurred in 21% of recipients in both groups. Glomerular filtration rates were significantly higher with EBK than SK at 12-months posttransplantation. At 1 year, graft survival for SK and EBK was 86% and 79%, respectively (P=1.000). Graft thrombosis occurred in 0% (0/9) of SK recipients in which an aortic cuff or conduit was used, 40% (2/5) of SK recipients without an aortic cuff, and 5% (1/19) of EBK recipients (P=0.03).

CONCLUSION

Short-term outcomes of kidneys from small pediatric donors are satisfactory when transplanted as SKs or en bloc; however, the absence of an aortic patch in SK transplantation is a risk factor for early thrombosis.

Superiority of pediatric en bloc renal allografts over living donor kidneys: a long-term functional study

BACKGROUND

Growing waiting list for kidney transplantation in the United States makes it imperative to expand donor pool to use of pediatric kidneys. Because en bloc pediatric kidneys double nephron numbers, it would be interesting to learn how they fare compared to living donor kidneys long term.

METHODS

Retrospective chart review was performed on all 72 pediatric en bloc and 75 live adult donor kidney recipients transplanted between January 1990 and December 2001. Long term graft function was assessed with glomerular filtration rate (GFR) using the abbreviated modification of diet in renal disease (MDRD) formula.

RESULTS

Pediatric donor was 16.9 +/- 11.2 months old and weighed 10.7 +/- 3.8 kg. Nine en bloc kidneys thrombosed at a mean of 4.2 days posttransplantation. Proteinuria was detected later posttransplantation in en bloc group (45.6 +/- 33.6 months vs. 23.4 +/- 16.3 months, P = 0.002). Pediatric en bloc recipients had significantly higher GFR up to 8 years posttransplantation. One-year graft survival was significantly better in live donor group (93.3% vs. 81.9%, P = 0.041) but five-year graft survival rates were similar (86.7% vs. 76.3%, P = 0.125). One-year and five-year patient survival rates were similar between en bloc and live donor groups (97.3% vs. 98.6%, P = 0.585 and 94.6% vs. 93.0%, P = 0.688, respectively).

CONCLUSION

Early postoperative graft thrombosis remain a challenge with pediatric en bloc renal transplants, but once the allografts survive early postoperative course, they provide better long-term function than living donor kidney transplants. In order to alleviate burden on waiting list, pediatric en bloc kidneys should be transplanted more often when available.

Solitary renal allografts from pediatric cadaver donors less than 2 years of age transplanted into adult recipients

BACKGROUND

Transplantation of solitary pediatric renal allografts from donors 2 years of age or younger into adult recipients is controversial.

METHODS

Between 1998 and 2001, 15 solitary renal allografts from pediatric donors 2 years of age or younger were transplanted into adult recipients. Thirty-three en bloc renal allografts transplanted between 1994 and 2001 were used for comparison. En bloc kidneys were considered for separation if they measured greater than or equal to 6 cm in length. Renal function (creatinine clearance [CrCl]) was estimated using the Cockroft-Gault formula.

RESULTS

Two-year graft survival for the solitary and en bloc groups were 93% and 77%, respectively (P =0.405). Five grafts were lost because of arterial thrombosis (four en bloc and one solitary). Ureteral complications occurred in three grafts in the en bloc group. One-year postoperative CrCl of the surviving solitary (n=14) and en bloc (n=26) grafts were 51.4+/-26.2 mL/min and 55.1+/-27.5 mL/min (P >0.05), respectively. Donor weight and kidney length were greater in the solitary group (14.3+/-3.5 kg and 6.3+/-0.4 cm, respectively) compared with the en bloc group (10.8+/-2.6 kg and 5.9+/-0.3 cm, respectively) (P =0.001 and P <0.001).

CONCLUSIONS

Separation of en bloc pairs into solitary allografts can be considered when the graft measures greater than or equal to 6 cm in length and donor weight is greater than or equal to 14 kg. The transplantation of solitary pediatric kidneys into adult recipients is successful, and the majority of pediatric en bloc allografts can be separated before transplantation.

Long-term follow-up of pediatric en bloc renal transplantation

We reviewed the outcomes of pediatric en bloc renal transplantation at two Canadian centers in the cyclosporine era. Between 1984 and 2002, 16 patients received pediatric en bloc renal transplants. Mean recipient age and weight were 45 +/- 17 years and 72.2 +/- 14.4 kg, respectively. En bloc kidneys were procured from donors aged 2.1 +/- 0.8 years (range, 0.7 to 4.0), weighing an average of 14.3 +/- 2.0 kg (range, 12 to 17). All en bloc kidneys were successfully transplanted without thrombosis. All patients received calcineurin inhibitors and corticosteroids. Only three patients received antibody-based induction therapy. Rejection episodes occurring in seven grafts were all successfully treated. Mean follow-up was 3.7 years (range 0.4 to 15.0). Mean serum creatinine values at 3 months and 1 and 3 years were 138.8 +/- 54.5 micromol/L, 118.6 +/- 38.1 micromol/L, and 95.1 +/- 24.4 micromol/L, respectively. The mean creatinine value of five patients with at least 5 years follow-up was 96.8 +/- 12.3 micromol/L. Three-year graft and patient survival rates were 94%. Two deaths with functioning grafts occurred secondary to cardiac and infectious etiologies. None of the grafts were lost independent of death. We conclude that en bloc transplantation has excellent short- and long-term results. Improving graft function after 3 years represented by reduced serum creatinine suggests that these kidneys have excellent renal reserve and growth potential.

Transplantation of Pediatric En Bloc Cadaver Kidneys into Adult Recipients: A Single-Center Experience

Faced with an extreme shortage of organs transplant professionals continue to explore various strategies to expand the donor pool. Transplantation of kidneys from older and very young donors are two such options. Although kidneys from young donors (less than 5 years of age) have been associated with a high rate of technical complications and suboptimal results, use of these kidneys en bloc has been advocated to improve the outcomes. We reviewed our experience with en bloc kidney transplantation at the University of Kentucky over the past 10 years. Between 1991 and 2000 ten patients underwent kidney transplantation using kidneys en bloc from donors <5 years age. The mean age of the donors was 2.8 years with a mean weight of 16 kg (range 13–21). Mean age of the recipients was 42 years. One patient lost the graft on day one from venous thrombosis. One patient lost the graft 7 years post-transplant from chronic rejection. All of the remaining patients are doing well with functioning grafts (mean follow-up 4.5 years; range 6 months to 10 years). Both one-year and five-year graft survival rates are 89 per cent. The present study confirms that excellent results can be achieved with kidney transplantation using kidney transplantation using kidneys en bloc from donors younger than 5 years of age.

Long-term results of en bloc transplantation of pediatric kidneys into adults using a vicryl mesh envelope technique

En bloc transplantation of pediatric kidneys into adults is a suitable measure to help correct the shortage of available kidneys. This practice, however, is not widespread because of the high incidence of vascular complications. Our institution has previously described a vicryl mesh technique for en bloc kidneys, with an attempt to reduce the incidence of vascular complications. The purpose of this study was to evaluate the long-term results of recipients with en bloc kidneys stabilized with this technique. The charts of 644 adult renal transplants performed between July 1987 and July 1999 were reviewed. During this period, 14 adult patients have received 14 pairs of en bloc pediatric kidneys using the vicryl mesh technique. All patients received OKT3 as an induction immunosuppression with cyclosporine started 10-14 d after the transplant. The median donor age was 24 months (range 14-84 months), and the median recipient age was 49 yr (range 23-68 yr). The mean recipient weight was 79 kg (range 60-114 kg). The mean cold ischemia time was 14.2 hr. None of the patients developed vascular or urological complications. Delayed graft function and moderate acute rejection occurred in one patient each. At a mean follow-up of 51 months (range 7-96 months), all 14 patients maintained excellent renal function with a mean creatinine of 1.01 mg/dL. Renal measurements pre-operatively and at follow-up ultrasound examinations were available in 9 patients, and the mean length of the kidneys had grown approximately 5.0 cm. These data demonstrate that minimal vascular and immunological complication rates can be achieved with pediatric en bloc kidneys using the vicryl mesh envelope technique.

The use of expanded criteria cadaver and live donor kidneys for transplantation

The use of expanded criteria donors (non-traditional donors) can help lessen the current shortage of kidneys available for transplantation. The use of older donors has accounted for a large measure of the increase in the organ donation rate; however, the most significant factors found to impact on transplant success negatively traditionally have been shown to be extremes of donor age and last-hour urine output. Less significant variables affecting success rates are average systolic blood pressure, terminal serum creatinine, and days of hospitalization. With the appropriate selection of organs from expanded donors, acceptable outcomes can be obtained. When living donors are selected properly, kidneys with anatomic variants without pathologic significance can be used safely. Kidneys with a heightened potential for the development of progressive disease should not be transplanted. Efforts to decrease the cold ischemia time by increasing the use of kidneys from expanded criteria donors may improve the outcome of transplantation further. Advances in surgical techniques, preservation solutions, and methods for predicting eventual long-term renal function in kidneys from expanded donors will be critical in allowing precise selection criteria for kidneys for transplantation, resulting in the optimum use of a scarce and precious resource. Until options such as xenotransplantation become clinically feasible, the challenge will be to identify which donor organs previously considered suboptimal can be used safely to expand the organ donor pool.

Risk factors for renal allograft survival from pediatric cadaver donors: an analysis of united network for organ sharing data

BACKGROUND

The shortage of cadaveric donors for kidney transplantation has prompted many centers to use cadaver kidneys from pediatric donors. Use of kidneys from pediatric donors has been shown to have a lower graft survival.

METHODS

Recipients receiving cadaver kidneys from pediatric and adult donors between 1988 and 1995 were analyzed. The data were obtained from United Network of Organ Sharing database. The actuarial kidney transplant graft survival was estimated by the Kaplan-Meier method. A logistic regression analysis was used to identify various risk factors for 1-year graft failure. Odds ratios (OR) were estimated for various risk factors.

RESULTS

Kidney transplant survival rates for donor age <18 years (n=12,838) at 1, 2, 3, 4, and 5 years were 81.5%, 76.3%, 71.3%, 66.4%, and 61.7%, respectively. The corresponding results for adult donors from age 18 to 50 years (n=35, 442) were 83.5%, 78.4%, 73.1%, 67.9%, and 62.4%, respectively, Log-rank test P<0.01. Pediatric donors were further divided into three groups according to donor age: group I (0-5 years), group II (6-11 years), and group III (12-17 years). The actuarial survival rates for 1, 3, and 5 years for group I (n=2198) were 73.6%, 63.3%, and 55.6%, respectively. The corresponding values for group II (n=2873) were 78.0%, 67.5%, and 57.8% and for group III (n=7767) were 85%, 75.0%, and 64.8%, respectively, P<0.01. Although the recipients of group I had lower graft survival, en bloc grafts (n=751) had much better 1-, 3-, and 5-year graft survival rates (76.3%, 67.7%, and 60.7%, respectively) compared with single grafts (n=1447; 72.2%, 61.1%, and 53.2%, P=0.02) from donors 0 to 5 years. Graft thrombosis as a cause of graft failure was seen in 10% of group I compared with 6% in group II and 5% in group III. In group I, lower OR were seen when an en bloc transplant was performed (0.688, P<0.01) and when donor body weight was>15 kg (0.547, P<0.01). However, OR were elevated in recipients of previous transplants (1.556, P<0.01), with prolonged cold ischemic time (1.097, P=0.03), for black recipients (1.288, P=0.03), and for recipients with body mass index> or =25 (1.286, P=0.02). Progressive increase in the donor age was associated with lower OR in group II (0.894, P<0.01).

CONCLUSIONS

(1) Overall, poorer graft survival was seen in pediatric donor transplants, (2) transplant kidney survival with en bloc kidneys was better than a single kidney from donors 0-5 years, (3) progressive increase in donor age was associated with improved graft survival when the donors were 6-11 years, whereas progressive increase in donor weight was associated with improved graft survival when the donors were 0-5 years.

Does renal mass exert an independent effect on the determinants of antigen-dependent injury?

The aim of this retrospective study was to determine whether nephron mass may exert a direct, independent effect on immunological tolerance. To this end, data corresponding to patients transplanted with en block pediatric kidneys (EBPK) (n=48) were compared with those of renal transplants with a low risk of hyperfiltration (LRH) comprised of recipients of a kidney from young donors (age 5-40 years) (n=173), and transplants with a high risk of hyperfiltration (HRH) comprised of patients who had received a graft from an elderly donor (older than 55 years) (n=91). All the patients had been subjected to the same immunosuppressive treatment. The median follow-up period was 54 months (6-127 months). The EBPK group showed lowest serum creatinine and highest creatinine clearance levels at each follow-up time. The rate of proteinuria >500 mg/day was 5.7% in EBPK, 7.4% in LRH, and 27.3% in HRH (P=0.000). The incidence of acute corticoresistant rejection was minor in EBPK (7.0% in EBPK, 21.3% in LRH, and 23.3% in HRH; P=0.04). Logistic regression analysis showed that the type of transplant was predictive of acute corticoresistant rejection [RR 5.33 (95% confidence interval (CI) 1.15-24.62) for HRH and RR 4.75 (95%CI 1.06-21.27) for LRH, P=0.03]. Multivariate analyses for graft failure due to chronic rejection and for graft failure due to acute rejection according to Cox's regression analysis demonstrated that HRH transplant was a significant predictive variable of both types of failure [4.08 (95%CI 1.27-13.04) for graft loss due to chronic rejection and 8.69 (95%CI 1.69-44.67) for graft loss due to acute rejection]. The present stratification of data according to nephronal mass would appear to indicate that the greater the mass, the lower the incidence of both acute and chronic rejection. This finding lends support to the hypothesis that a large mass of transplanted tissue relative to recipient mass may dampen the immune response.

Diffuse glomerular basement membrane lamellation in renal allografts from pediatric donors to adult recipients

The transplantation of kidneys from pediatric cadaveric donors into adult recipients is performed in many centers. However, some studies indicate that the outcome of such renal transplants may be inferior compared with that of adult donors, particularly if the donor is an infant. Morphologic studies of failed pediatric donor kidneys in adult recipients describe various degrees of segmental or global glomerular sclerosis. The authors have performed ultrastructural examinations on such transplants and have identified six cases with diffuse irregular lamellation of the glomerular basement membrane (GBM), a change that may develop as early as 10 weeks after transplantation. The age of all donors was < or =6 years; three were infants. The incidence of the lesion was 9% at our institution in renal transplant patients who received a graft from donors <10 years old. Diffuse GBM lamellation has not been found in renal transplants from adult donors. Light microscopy showed various degrees of diffuse mesangial expansion, usually with segmental glomerular sclerosis. The patients had severe proteinuria. While recurrent focal segmental glomerular sclerosis (FSGS) has to be excluded, such diffuse GBM lamellation is generally not seen in recurrent FSGS cases. The pathogenesis of the lesion is most likely related to hyperperfusion injury of small pediatric donor kidneys grafted into adult recipients.

Early proteinuria in renal transplant recipients treated with cyclosporin

PURPOSE

To establish the risk profile for the development of proteinuria in the first months after renal transplantation and to disclose the prognostic significance of this finding.

DESIGN

We conducted an observational historic cohort study.

SETTING

We conducted the study in a tertiary care hospital renal transplantation unit covering a potential population of approximately 2 million. We made extensive use of suboptimal donors.

POPULATION

In our unit, 560 cadaveric renal transplants were performed between January 1988 and June 1997, under Cyclosporine immunosuppression, with a minimum follow up of 1 year.

METHOD

The risk profile analysis explored early clinical factors reported to be related to the late course of renal transplantation. The study of the prognostic significance of proteinuria included survival analysis and correlation with late markers of graft dysfunction, taking into consideration the intensity and persistence of early proteinuria. A multivariate approach was used in all cases.

RESULTS

Early proteinuria was strongly associated with delayed graft function (odds ratio [OR] 1.03/day of dialysis), acute rejection (OR 1.7 for steroid-sensitive and 6.2 for steroid-resistant rejection), renal transplant to a hypersensitized recipient (OR 2.5), and pediatric (<5 years)(OR 4.1) or older (>60 years)(OR 3.0) donors. The predictive model for persistency of proteinuria was very similar, whereas transient proteinuria could not be adequately modeled. Increasing intensity of proteinuria was strongly associated with poor patient and graft survival. Persistent, but not transient, proteinuria supported this relationship.

CONCLUSIONS

Proteinuria appearing early after renal transplantation is strongly associated with delayed graft function, acute rejection, and the use of pediatric or older donors. Whatever its background, proteinuria is a strong predictor of poor patient and graft survival. This effect is directly related to the intensity and persistence of the disorder.

Transplantation of pediatric en bloc cadaver kidneys into adult recipients

BACKGROUND

To maximize the renal donor pool, cadaveric pediatric en bloc kidneys have been transplanted as a dual unit by some transplant centers. We compared the short- and long-term outcomes of adult recipients of cadaveric pediatric en bloc renal transplants versus those of matched recipients of cadaveric adult kidneys.

METHODS

Thirty-three adults who received pediatric en bloc kidney transplants between April 1990 and September 1997 were retrospectively identified and were compared with 33 matched adults who received adult cadaveric kidney transplants. The groups were identical for transplantation era, immunosuppression, recipient sex, race, cause of renal failure, mean weight, and follow-up duration (37.8 vs. 37.5 months). The mean recipient age study versus control was lower (36.3 vs. 48.9 years, P=0.0003). Results. There was no difference between the en bloc and adult donor groups in the 3-year patient survival rates (95% vs. 87%, P=0.16) or the 3-year graft survival rates (87.3% vs. 84.2%, P=0.35). Further, there was no difference in en bloc patient or en bloc graft survival time stratified by recipient age (14-44 vs. >45 years, P=0.11), en bloc donor age (<24 vs. >24 months, P=0.39), or recipient weight (<60, 61-75, >75 kg; P=0.60). Differences in serum creatinine (mg/dl) for the en bloc versus the control group at the time of discharge (3.0 vs. 7.8 mg/dl, P=0.06), at 1 year (1.4 vs. 2.0 mg/dl, P=0.06), and at 2 years (1.1 vs. 1.6 mg/dl, P=0.14) had dissipated by the time of the 5-year follow-up examination (1.1 vs. 1.6 mg/dl, P=0.14). Vascular complications were more prevalent in the en bloc group: renal vein thrombosis (one case), thrombosis of donor aorta (two cases), arterial thrombosis of one renal moiety (two cases), and renal artery stenosis (two cases). There were no differences between groups in delayed graft function, acute or chronic rejection, posttransplant hypertension, posttransplant protein-uria, or long-term graft function.

CONCLUSIONS

Collectively, these data indicate that transplanting pediatric en bloc kidneys into adult recipients results in equivalent patient and graft survival compared with adult cadaveric kidneys. Further, the data also suggest that pediatric en bloc kidneys need not be strictly allocated based on recipient weight or age criteria.

Renal transplantation: surgical aspects, complications and results

Despite the fact that kidney transplants have routinely been successfully performed for over 30 years there continues to be challenges for the transplant surgeon. These include a static donor pool, growing recipient list, declining number of ideal donors and greater reliance on marginal donors. Innovative methods to deal with these problems continue to be sought.

Clinical outcome of renal transplantation. Factors influencing patient and graft survival

The 1-year graft survival rate for primary cadaver kidney transplants performed in the US during the past 9 years was 82%, and it was 94% when living donor kidneys were transplanted. After the first year, however, half of the surviving cadaveric grafts will fail within 8 years. This late rate has not changed substantially in the past 20 years. This article describes some of the factors that affect long-term graft and patient survival rates.