Impact of posterior urethral valves on pediatric renal transplantation: a single-center comparative study of 297 cases

Clinical considerations in adults with history of posterior urethral valves

INTRODUCTION

Management of patients with posterior urethral valves (PUV) is commonplace for many pediatric urologists, however adult providers may be far less familiar with this diagnosis, its management and long-term ramifications. As urologic management of these patients has evolved, clinical outcomes have substantially improved with many more patients now surviving into adulthood. These patients remain at increased risk of morbidity due to their condition and therefore are likely to benefit from long term follow-up with adult providers.

OBJECTIVE

In this review we analyze the psychosocial impacts of PUV on adults, evaluate long term transplant outcomes in PUV patients and discuss effective clinical management strategies of bladder dysfunction in adult PUV patients.

STUDY DESIGN

A retrospective literature review was performed using the MEDLINE (Pubmed) electronic database using key words such as "posterior urethral valve", "quality of life", "sexual function", "transplant outcomes", "bladder dysfunction", "mitrofanoff" etc. to identify relevant studies.

RESULTS

Generally, the quality of life of PUV patients is good, those suffering from renal insufficiency or lower urinary tract symptoms, specifically incontinence, appear to be a group that may benefit from more intensive follow-up. Good long-term kidney transplant (KT) function and survival can be achieved in patients with PUV. Rigorous management to optimize bladder function and close follow-up, are key for long term graft survival after KT.

DISCUSSION

The chronicity of PUV warrants adult providers to be not only well versed in the pathophysiology of the disease, but well prepared to care for these patients as they transition into adulthood.

CONCLUSION

Additional studies addressing psychosocial, clinical and transplant outcomes of adults with PUV are necessary to develop optimal long-term follow-up regimens for these patients.

Clean Intermittent Catheterization in Children under 12 Years Does Not Have a Negative Impact on Long-Term Graft Survival following Pediatric Kidney Transplantation

BACKGROUND

Congenital anomalies of the kidneys and urinary tract (CAKUTs) are one of the most prevalent primary causes of end-stage renal disease (ESRD) in young children, and approximately one-third of these children present with lower urinary tract dysfunction (LUTD). Many children with LUTD require therapy with clean intermittent catheterization (CIC). CIC commonly leads to bacteriuria, and considerations have arisen regarding whether CIC in immunosuppressed children is safe or whether repeated febrile urinary tract infections (UTIs) may lead to the deterioration of kidney graft function.

MATERIAL AND METHODS

We retrospectively reviewed all cases of primary kidney transplantation performed in our center between 2001 and 2020 in recipients aged less than twelve years. The number of episodes of febrile UTIs as well as the long-term kidney graft survival of children undergoing CIC were compared to those of children with urological causes of ESRD not undergoing CIC, as well as to those of children with nonurological causes of ESRD.

RESULTS

Following successful kidney transplantation in 41 children, CIC was needed in 8 of these patients. These 8 children undergoing CIC had significantly more episodes of febrile UTIs than did the 18 children with a nonurological cause of ESRD (p = 0.04) but not the 15 children with a urological cause of ESRD who did not need to undergo CIC (p = 0.19). Despite being associated with a higher rate of febrile UTIs, CIC was not identified as a risk factor for long-term kidney graft survival, and long-term graft survival did not significantly differ between the three groups at a median follow-up of 124 months.

CONCLUSIONS

Our study demonstrates that, under regular medical care, CIC following pediatric transplantation is safe and is not associated with a higher rate of long-term graft loss.

Outcomes of kidney transplantation in patients with congenital anomalies of the kidney and urinary tract: a propensity-score-matched analysis with case-control design

BACKGROUND

We compared long-term outcomes after kidney transplantation (KTx) in patients with and without congenital anomalies of the kidney and urinary tract (CAKUT).

METHODS

KTx recipients (KTRs) with CAKUT in 1980-2016 were identified; their hard copy and electronic medical records were reviewed and compared to a propensity-score-matched control group (non-CAKUT) from the same period. The primary outcomes were graft loss or death with a functioning graft; secondary outcomes included posttransplant urinary tract infections (UTIs) and biopsy-proven rejection (BPR).

RESULTS

: We identified 169 KTRs with CAKUT and 169 matched controls. Median follow-up was 132 (IQR: 75.0-170.0) months. UTIs were more common in CAKUT patients compared to non-CAKUT group (20.7% vs 10.7%; p = 0.01). Rates of BPR were similar between the two groups. In Kaplan-Meier analysis, 10-year graft survival rates were significantly higher in the CAKUT group than in the non-CAKUT group (87.6% vs 69.2%; p < 0.001), while patient survival rates were similar. In multivariate Cox regression analyses, CAKUT (HR: 0.469; 95% CI: 0.320-0.687; p < 0.001) and PRA positivity before transplantation (HR: 3.756; 95% CI: 1.507-9.364; p = 0.005) predicted graft loss.

DISCUSSION

Graft survival in KTRs with CAKUT appears superior to KTRs without CAKUT. Transplant centers should develop multidisciplinary educational and social working groups to support and encourage CAKUT patients with kidney failure to seek for transplants.

Spectrum of lower urinary tract symptoms after renal transplant among adult non-urologic anuric patients and their management in a tertiary care center

INTRODUCTION

Lower urinary tract symptoms (LUTS) in a post-transplant patient can lead to several complications including recurrent UTI and deterioration of the graft kidney function. The aim of this study is to investigate the spectrum of LUTS, possible complications resulting from it and its management after renal transplant in pre-transplant anuric patients operated in our tertiary care institute.

MATERIALS AND METHODS

It was a retro-prospective observational study done on post-transplant patients operated in this institute from December 2016 to December 2020. Among 165 patients operated during this period 50 male and 21 female patients were finally included in this study. Urinary symptoms were evaluated using the IPSS Questionnaire. Pre and post-surgery Uroflowmetry findings were compared. Urodynamic assessment was done at least 6 months after surgery to determine the cause behind such symptoms. The data was analyzed with the help of standard statistical methods and SPSS 21 software.

RESULTS

The most common LUTS among the post renal transplant patients were frequency and nocturia. There was a marked improvement in voided volume and urinary flow in most of the patients. In 11 male and 7 female patients LUTS symptoms were moderate to severe and were seldom associated with recurrent UTI and graft compromise. A cautious approach in these patients helped in early diagnosis of the etiology behind LUTS, which were treated accordingly.

CONCLUSION

LUTS should be carefully evaluated before renal transplantation. Postoperatively moderate to severe LUTS symptoms should be thoroughly investigated so that graft compromise and related complications can be prevented by early intervention.

Inhibition of DNA methylation during chronic obstructive bladder disease (COBD) improves function, pathology and expression

Partial bladder outlet obstruction due to prostate hyperplasia or posterior urethral valves, is a widespread cause of urinary dysfunction, patient discomfort and also responsible for immense health care costs. Even after removal or relief of obstruction, the functional and pathologic aspects of obstruction remain as a chronic obstructive bladder disease (COBD). Epigenetic changes, such as DNA methylation, contribute to the persistent character of many chronic diseases, and may be altered in COBD. We tested whether candidate genes and pathways and the pathophysiology of COBD were affected by a hypomethylating agent, decitabine (DAC). COBD was created in female Sprague-Dawley rats by surgical ligation of the urethra for 6 weeks, followed by removal of the suture. Sham ligations were performed by passing the suture behind the urethra. After removal of the obstruction or sham removal, animals were randomized to DAC treatment (1 mg/kg/3-times/week intraperitoneally) or vehicle (normal saline). Bladder function was non-invasively tested using metabolic cages, both one day prior to de-obstruction at 6 weeks and prior to sacrifice at 10 weeks. Residual volume and bladder mass were measured for each bladder. Bladders were examined by immunostaining as well as qPCR. The effects of DNA methyltransferase (DNMT)-3A knockout or overexpression on smooth muscle cell (SMC) function and phenotype were also examined in bladder SMC and ex vivo culture. Residual volumes of the DAC treated group were not significantly different from the NS group. Compared to COBD NS, COBD DAC treatment helped preserve micturition volume with a significant recovery of the voiding efficiency (ratio of the maximum voided volume/maximum bladder capacity) by one third (Fig. 1, p > 0.05). Brain-derived neurotrophic factor (BDNF) variants 1 and 5 were upregulated by COBD and significantly reduced by DAC treatment. Deposition of collagen in the COBD bladder was reduced by DAC, but gross hypertrophy remained. In bladder SMC, DNMT3A overexpression led to a loss of contractile function and phenotype. In bladders, persistently altered by COBD, inhibition of DNA-methylation enhances functional recovery, unlike treatment during partial obstruction, which exacerbates obstructive pathology. The underlying mechanisms may relate to the gene expression changes in BDNF and their effects on signaling in the bladder.

Outcome of a thorough screening of lower urinary tract function in all pediatric kidney recipients

LUTD is one of the possible factors influencing pediatric kidney graft outcomes. This study evaluates the results of a thorough assessment of voiding behavior in pediatric transplants. Data of patients with kidney disease of nephrological origin are compared to those with urological origin. A single-center analysis of pediatric kidney transplants performed from 2005 to the present was executed. Donor and recipient characteristics as well as voiding and drinking habits were documented using FVCs and uroflowmetry with PVR measurements. LUTD was defined by a mean MVV >150% or <65% of the EBC for age, abnormal uroflowmetry, PVR repeatedly >15% of EBC or >20 mL, abnormal voiding patterns or behavior, and presence of LUT symptoms. LUTD was diagnosed in 71% of the 56 screened children and more present in urological origin of kidney disease (100%) compared to nephrological origin (61%, P = .005). Individual presence of LUT symptoms, abnormal voiding behavior, FVC parameters, UTIs, and uroflowmetry/PVR parameters were not different between the two groups. Polyuria after transplantation was seen in 63% of patients, mainly in the first post-transplant years and recipients aged <10 years. Time after transplantation was a significant independent predictive factor for the presence of LUTD. LUTD is common in all pediatric kidney recipients and underestimated in those with a nephrological origin of disease. Active screening, monitoring and a care attention plan prior to transplantation and during follow-up, is advocated to optimize outcomes for all patients.

Comparison of the outcomes of the pediatric kidney transplantation between recipients below and above 15 kg: a single center retrospective study

BACKGROUND

The renal transplantation is the best treatment for end-stage renal disease in children. We present the findings of an analysis of our institution's paediatric transplant outcomes comparing recipients under 15 kg, who represent this potentially higher risk group, to those above 15 kg.

METHODS

We retrospectively identified consecutive paediatric kidney transplants from a prospectively collected database for analysis. We included all recipients under the age of 18 years at the time of transplant between 2006 and 2018 without any exclusion criteria. The primary outcome was death-censored graft survival at 1 year, 5 years and 10 years.

RESULTS

109 paediatric kidney transplants were performed in 100 children. Graft survival in the all population was 98%, 96% and 76% at 1 year, 5 years and 10 years, respectively. Recipient weight below 15 kg was not found to be a risk factor of graft loss. Overall, we found no individual factor to be statistically significantly associated with renal graft lost. The overall complication rate was 16% (18/109) with 12 early complications (11%) and 6 late ones (5%).

CONCLUSION

Kidney transplantation in children weighing < 15 kg seems safe and offers the same patient and graft survival outcomes as in other (> 15 kg) pediatric recipients with equally low complication rates.

Long-Term Renal Transplant Outcome in Patients With Posterior Urethral Valves. Prognostic Factors Related to Bladder Dysfunction Management

Introduction: To obtain a successful renal transplant (RT) outcome in patients with posterior urethral valves (PUV), it is necessary to accomplish an adequate bladder dysfunction treatment. Our aim was to determine prognostic factors related to bladder dysfunction management in long-term RT outcome in patients with PUV. Methods: A retrospective review of patients with PUV who received a first RT after 1985 in our institution with at least 5 years of follow-up was performed. Variables analyzed included prenatal diagnosis, age of diagnosis, initial presentation and management, bladder dysfunction treatment, other surgical treatments, pre-transplant dialysis, age of transplantation, type of donor, immunosuppression regimen, vascular and urological complications, rejections episodes, and graft survival. Results: Fifty-one patients were included in the analysis. Prenatal diagnosis was done in 37.3%. Median age of diagnosis was 0.30 (0-88) months. Initial presentation was vesicoureteral reflux (VUR) in 78% and obstructive ureterohydronefrosis in 35.3%. Initial management was valve ablation (29.4%), pyelo-ureterostomy (64.7%), and vesicostomy (5.9%). In 33.3%, a type of bladder dysfunction treatment was performed: 21.6% bladder augmentation (BA), 15.7% Mitrofanoff procedure, 17.6% anticholinergic drugs, and 27.5% clean intermittent catheterization (CIC). Pre-transplant dialysis was received by 66.7%. Transplantation was performed at 6.28 ± 5.12 years, 62.7% were cadaveric and 37.3% living-donor grafts. Acute rejection episodes were found in 23.6%. Urological complications included recurrent urinary tract infections (UTIs) (31.4%); native kidneys VUR (31.4%); graft VUR (45.1%); and ureteral obstruction (2%). Vascular complications occurred in 3.9%. Mean graft survival was 11.1 ± 6.9 years. Analyzing the prognostic factor that influenced graft survival, patients with had CIC or a Mitrofanoff procedure had a significant better long-term graft survival after 10 years of follow-up (p < 0.05), despite of the existence of more recurrent UTIs in them. A better graft survival was also found in living-donor transplants (p < 0.05). No significant differences were observed in long-term graft survival regarding native kidneys or graft VUR, BA, immunosuppression regimen, or post-transplant UTIs. Conclusion: Optimal bladder dysfunction treatment, including CIC with or without a Mitrofanoff procedure, might result in better long-term graft survival in patients with PUV. These procedures were not related to a worse RT outcome in spite of being associated with more frequent UTIs.

Comparative outcome analysis of pediatric kidney transplant in posterior urethral valves children with or without pretransplant Mitrofanoff procedure

BACKGROUND

Urinary diversion using catheterizable channel among posterior urethral valve (PUV) patients may help to alleviate the functional concerns of the bladder on the allograft. Herein, we review our series of PUV patients undergoing renal transplants at a single institution to determine outcomes between those with and without pretransplant Mitrofanoff.

METHODS

PUV cases in our transplant database from 2000 to 2017 were identified. Data collected included clinical demographics, presentation of PUV, bladder function, implementation of dialysis and donor type. Post-transplant variables included graft function, and bladder function including incontinence and UTI development. Comparison between with vs without pretransplant Mitrofanoff patient groups was performed using Fisher's exact and t test analysis.

RESULTS

Overall, 22 cases were analyzed. The majority (77%) had a prenatal diagnosis of PUV, and 23% had a symptomatic presentation. Pretransplant Mitrofanoffs were performed in 40.9% of cases. The overall age at transplant was 10 ± 5 years. Five percent experienced post-transplant incontinence and 23% UTIs. No difference between groups was noted in variables including age at transplant, the timing of PUV diagnosis. Mitrofanoff group patients had more symptomatic febrile UTIs than those without Mitrofanoff (67% vs 15%; P = .03); however, there was no difference in post-transplant UTI development. Furthermore, the Mitrofanoff group seems to have later onset of dialysis or need for transplant (age at the start of dialysis 36 ± 56 vs 156 ± 25 months, P < .001).

CONCLUSION

Our study suggests that patients with early PUV diagnoses who develop symptomatic UTI may benefit from early creation of a Mitrofanoff cathetherizable channel, which is associated with delayed ESRD progression and need for dialysis.

Renal, Bladder and Sexual Outcomes in Adult Men with History of Posterior Urethral Valves Treated in Childhood

OBJECTIVE

To determine the adulthood outcomes of bladder, kidney, and sexual functions of posterior urethral valve (PUV) patients.

MATERIALS AND METHODS

The records of patients who were treated for PUV between 1980, and 2001 and aged ≥18 years by the end of 2019 were retrospectively reviewed. Patients with complete adulthood data were included in the study. Renal, bladder, and sexual functions were assessed. Adulthood uroflowmetry results of 22 patients were also evaluated.

RESULTS

Thirty-nine patients with complete adulthood data out of 89 were included. The median follow-up time was 22.7 years (15-33 years). Median age at initial surgery for PUV was 36 months (1-168 months), and median age at last follow-up was 26 years (18-46 years). Lower urinary tract dysfunction was noted in 15 (38%) patients. In 22 patients (56%) with uroflowmetric analyses, median values of Q_max, voided volume, and post voiding residual urine volume were 20.5 mL/sec (7-43 mL/sec), 389 mL (154-1750 mL), and 18.5 mL (range 0-190 mL), respectively. Nineteen patients (48.7%) had normal glomerular filtration rate, 2 patients (5.1%) had chronic kidney disease, and the remaining 18 patients (46.1%) had end stage renal disease, 14 (35.9%) of whom underwent renal transplantation. Thirty-two patients (82%) had sexual function evaluation, none of which reported erectile dysfunction. However, 4 patients (12.5%) reported slow ejaculation. Five patients fathered a child whereas infertility was observed in 2 patients.

CONCLUSION

After 2 decades, glomerular filtration rate was normal almost in half of the PUV patients while lower urinary tract dysfunction was detected in 38%. Furthermore, erectile dysfunction was rare.

Survival and Kidney Outcomes of Children with an Early Diagnosis of Posterior Urethral Valves

BACKGROUND AND OBJECTIVES

Posterior urethral valve is the most common cause of bladder outlet obstruction in infants. We aimed to describe the rate and timing of kidney-related and survival outcomes for children diagnosed with posterior urethral valves in United States children's hospitals using the Pediatric Health Information System database.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This retrospective cohort study included children hospitalized between January 1, 1992 and December 31, 2006, who were in their first year of life, had a diagnosis of congenital urethral stenosis, and underwent endoscopic valve ablation or urinary drainage intervention, or died. Records were searched up to December 31, 2018 for kidney-related mortality, placement of a dialysis catheter, and kidney transplantation. Cox regression analysis was used to identify risk factors, and Kaplan-Meier survival analysis used to determine time-to-event probability. Subgroup survival analysis was performed with outcomes stratified by the strongest identified risk factor.

RESULTS

Included were 685 children hospitalized at a median age of 7 (interquartile range, 1-37) days. Thirty four children (5%) died, over half during their initial hospitalization. Pulmonary hypoplasia was the strongest risk factor for death (hazard ratio, 7.5; 95% confidence interval [95% CI], 3.3 to 17.0). Ten-year survival probability was 94%. Fifty-nine children (9%) underwent one or more dialysis catheter placements. Children with kidney dysplasia had over four-fold risk of dialysis catheter placement (hazard ratio, 4.6; 95% CI, 2.6 to 8.1). Thirty-six (7%) children underwent kidney transplant at a median age of 3 (interquartile range, 2-8) years. Kidney dysplasia had a nine-fold higher risk of kidney transplant (hazard ratio, 9.5; 95% CI, 4.1 to 22.2).

CONCLUSIONS

Patients in this multicenter cohort with posterior urethral valves had a 5% risk of death, and were most likely to die during their initial hospitalization. Risk of death was higher with a diagnosis of pulmonary hypoplasia. Kidney dysplasia was associated with a higher risk of need for dialysis/transplant.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2019_10_03_CJN04350419.mp3.

Long-term outcome of kidney transplantation in patients with congenital anomalies of the kidney and urinary tract

BACKGROUND

Congenital anomalies of the kidney and urinary tract (CAKUT) are a leading cause of end-stage kidney failure in the young. However, there is limited information on long-term outcomes after kidney transplantation in this group. We explored the outcomes of kidney transplant in patients with the 3 most common severe forms of CAKUT: posterior urethral valves (PUV), reflux nephropathy and renal hypoplasia/dysplasia.

METHODS

Data were extracted from the Australian & New Zealand Dialysis & Transplant Registry on first kidney transplants performed between 1985 and 2015 in recipients with a primary diagnosis of PUV, renal hypoplasia/dysplasia or reflux nephropathy (under the age of 30 years). Using multivariate Cox regression, we compared death-censored graft survival between the three groups.

RESULTS

One hundred twenty-seven patients with PUV, 245 with hypoplasia/dysplasia and 727 with reflux nephropathy were included. A 10-year graft survival in PUV, hypoplasia/dysplasia and reflux nephropathy was 70%, 76% and 70%, respectively and a 20-year graft survival was 30%, 53% and 49%. After adjusting for age at transplant, graft source and HLA matching, there was evidence for poorer graft survival in PUV (HR, 1.65; 95% CI, 1.15 to 2.38).

CONCLUSIONS

Graft survival of the first transplant in CAKUT is favourable at 10 years; however, recipients with PUV have increased risk of graft loss beyond a 10-year post-transplant, which may be related to bladder dysfunction.

Surgical Challenge in Pediatric Kidney Transplant: Lower Urinary Tract Abnormality

Lower urinary tract abnormalities are difficult to resolve in pediatric kidney transplant patients. Measure of residual urine, voiding cystourethrography, retrograde urethrography, cystometry, electromyography of urethral external sphincter muscle, urethrometry, and uroflowmetry are the primary methods for evaluation of lower urinary tract abnormalities. Endoscopic resection or ablation of urethral valves is required in children with posterior urethral valve to treat obstruction, but bladder function does not always recover and may deteriorate to end-stage renal failure even after the obstruction is released. This bladder dysfunction in posterior urethral valve defines valve bladder syndrome. Vesicoureteral reflux caused by high vesical pressure can cause even worse renal graft function posttransplant. In our patient group, urinary diversion occurred with Mitrofanoff conduit using an appendix in 6 children, a Yang-Monti channel conduit using ileum in 1 patient, with cystostomy in 3 children, and with augmented cystoplasty in 9 children before or simultaneously with kidney transplant. These procedures should be selected based on the type of lower urinary tract abnormality including bladder function. Recently, we have preferred a continent diversion for self-catheterization in children with lower urinary tract abnormalities. We have conducted 9 augmented cystoplasty procedures using a portion of the sigmoid colon or ileum. Seventeen children retained their own bladders when the transplant ureter was implanted. Most patients needed clean intermittent catheterization, depending on the residual urine volume and a bladder function. Ten-year graft survival rate in kidney transplant in our department is 98% in 36 children with lower urinary tract abnormalities. Lower urinary tract abnormality is not always a risk factor for pediatric kidney transplant; however, a preoperative evaluation is important to choose the best option for urinary diversion.

Pre-transplant management of valve bladder: a critical literature review

OBJECTIVE

Indications, timing and problems related to augmentation cystoplasty (AC), in the context of posterior urethral valves (PUV) and renal transplantation (RT) are ill defined. Associated bladder dysfunction (BD) is not a stable condition and may cause the loss of the renal graft. Polyuria, accentuates BD and seems to improve after RT. The objective of this research is to critically review the available literature, aiming to rationalize the treatment of PUV with BD in the context of end stage renal disease (ESRD).

MATERIALS AND METHODS

A thorough literature review was performed. Pertinent papers were, critically analyzed and classified according to the level of evidence.

RESULTS

Data relating to PUV, RT and AC showed low levels of evidence. Results of RT in PUV cases with adequate management of BD were comparable to those suffering from other causes of ESRD. Bladder function can recover spontaneously after urinary undiversion. There were no established criteria to indicate AC in the context of ESRD and PUV or to define the ideal protocol to treat associated vesicoureteral reflux (VUR). Urinary tract infections (UTIs) were more frequent in transplanted PUV patients; this is possibly related to the inadequate control of BD, especially after AC. AC is feasible after RT with outcomes comparable to preemptive ones.

CONCLUSION

AC increases the risk of UTI after RT. Preemptive AC should be constructed only if the risks associated with increased bladder pressures exceed those associated with AC. Adequate management of BD is essential to improve bladder function and to minimize UTIs. AC is feasible after RT, with complication rates similar to the ones performed beforehand. Since a considerable number of PUV patients with high-pressure bladders eventually develop myogenic failure, it seems logical to postponing AC in this population, as long as they are under close surveillance.

Does bladder augmentation negatively affect renal transplant outcome in posterior urethral valve patients?

OBJECTIVE

Although renal transplant (RT) is a safe and effective treatment for end-stage renal disease, the outcome of RT has been mixed for posterior urethral valve (PUV) patients. In addition, some PUV patients need an augmentation cystoplasty (AC), which may negatively affect their RT outcome. The aim of this study is to compare RT outcome between PUV children with and without AC.

MATERIALS AND METHODS

Between 1985 and 2012 a total of 309 children received 369 RTs at our institution. Among these patients, 36 were had classified as having PUV. Of these, 12 underwent an AC before RT (AC group) and 24 did not (controls). Data, including age at transplant, allograft source, urological complications, urinary tract infection (UTI) incidence, the presence of vesicoureteral reflux (VUR), and patient and graft survival, were compared between groups.

RESULTS

Mean age at RT and mean follow-up were 7.6 versus 7.9 years and 8.9 versus 7.9 years in the AC group and in the control group, respectively (not significant [NS]). Allografts were from living donors in 50% of the AC group and in 41.6% of the controls (NS). The rate of UTI was 0.02 UTI/patient/year and 0.004 UTI/patient/year in the AC and control group, respectively (p = 0.001). Of the nine patients with UTI in the augmented group, five (55.5%) had VUR, while 5/8 (62.5%) patients in the control group with UTI had VUR. All patients with VUR in either group had UTIs previously. Of the five AC patients with more than three UTIs, two (40%) were non-compliant with clean intermittent catheterization (CIC), and UTI incidence was not associated with either a Mitrofanoff conduit or the urethra being used for CIC. Graft function at the end of study was 87.8 ± 40.5 ml/min/m(2) in the AC group and 88.17 ± 28.20 ml/min/m(2) in the control group (NS). The 10-year graft survival rate was 100% in AC group and 84.8% in controls. Two patients in the AC group lost their grafts (mean follow-up 13.3 ± 0.8 years) and five in the control group (mean follow-up 7.1 ± 4.7 years).

CONCLUSIONS

Bladder augmentation does not negatively affect renal outcome in PUV patients undergoing transplantation. However, recurrent UTIs are more frequent in transplanted PUV patients with an AC than in those without AC, and they are generally related to non-compliance with CIC or the presence of VUR but, mostly, they will not result in impaired graft function.

Vascular anastomosis for paediatric renal transplantation and new strategy in low-weight children

The technical aspects of RT in low-weight children should be specific, particularly with regard to VA. This retrospective study assesses the main VA options in paediatric RTs and proposes a new strategy for renal artery trajectory when using the Ao and the right iVC. The sample included 81 patients and was categorized into a group of children weighing <16 kg and the other group of children weighing 16 kg or more. The smaller children received the graft predominantly on the Ao and iVC (63%); however, the VA options varied in children weighing more than 16 kg, with anastomoses predominantly to the common iliac vessels (46%). In the first group, when the Ao was the selected vessel for anastomosis on the right side, the trajectory adopted for the transplanted kidney artery was posterior to the iVC. This strategy may reduce the risk of compression of the iVC by the renal artery of the donor kidney and may reconstitute the normal anatomy of the renal artery. Moreover, it did not represent a risk factor for graft loss in this sample.