Successful renal transplantation in children with posterior urethral valves

Timing of reconstruction of the lower urinary tract in pediatric kidney transplant recipients: A CERTAIN multicenter analysis of current practice

BACKGROUND

Preexistent LUTD are considered a hostile environment, which might negatively impact KTx survival. In such cases, surgical reconstruction of the bladder is required. However, there is still disagreement on the optimal timing of the reconstruction procedure.

METHODS

This is a multicenter analysis of data from the CERTAIN Registry. Included were 62 children aged 8.18 ± 4.90 years, with LUTD. Study endpoints were the duration of initial posttransplant hospitalization, febrile UTIs, and a composite failure endpoint comprising decline of eGFR, graft loss, or death up to 5 years posttransplant. Outcome was compared to matched controls without bladder dysfunction.

RESULTS

Forty-one patients (66.1%) underwent pretransplant and 14 patients (22.6%) posttransplant reconstruction. Bladder augmentation was performed more frequently in the pretransplant (61%) than in the posttransplant group (21%, p = .013). Outcome in the pre- and posttransplant groups and in the subgroups of patients on pretransplant PD with major bladder surgery either pre- (n = 14) or posttransplant (n = 7) was comparable. Outcomes of the main study cohort and the matched control cohort (n = 119) were comparable during the first 4 years posttransplant; at year 5, there were more events of transplant dysfunction in the study cohort with LUTD than in controls (p = .03).

CONCLUSIONS

This multicenter analysis of the current practice of LUTD reconstruction in pediatric KTx recipients shows that pre- or posttransplant surgical reconstruction of the lower urinary tract is associated with a comparable 5-year outcome.

Antenatal and postnatal management of posterior urethral valves: where do we stand?

Introduction

Posterior urethral valve (PUV) is the leading etiology of lower urinary tract obstruction (LUTO) in boys and is an important cause of end-stage renal disease (ESRD) in children. The aim of this article is to review the current status on antenatal intervention for PUV as well as postnatal medical and surgical management.

Main body

MEDLINE, EMBASE, Pubmed and Google Scholar search was conducted throughout December 2020 using the keywords: posterior urethral valves, congenital urinary obstruction, antenatal, valve bladder syndrome, medical, anticholinergics, alpha blocker, antibiotics, biofeedback, diversion, augmentation cystoplasty and renal transplantation. Only papers written in English were included. The relevant literature was summarized. Despite advances in antenatal intervention for fetal LUTO, it remains associated with considerable fetal and maternal morbidity. Patient selection criteria for antenatal intervention are greatly debated. Fetal intervention has resulted in improved perinatal survival in properly selected cases, with a questionable benefit to postnatal renal function. There is decent evidence supporting the use of anticholinergics in infants and young children following valve ablation, with less robust evidence advocating alpha blockers, overnight catheter drainage and biofeedback. The role of urinary diversion remains contentious. Optimizing bladder dynamics is crucial for successful renal transplantation outcomes.

Conclusion

While antenatal intervention has failed to improve renal function outcomes of PUV, patient-centered medical and sometimes surgical interventions can help delay the progression of chronic kidney disease. Lifelong monitoring and management of the associated bladder dysfunction is indispensable even after successful renal transplantation.

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.

Long-term outcome of pediatric renal transplantation in boys with posterior urethral valves

PURPOSE

To determine whether there is a difference in the outcome of renal transplantation (RT) in patients with posterior urethral valves (PUV) and children with non-uropathy related end stage renal disease.

METHODS

Data were acquired retrospectively. We analyzed possible factors that influence the function of renal allografts and graft survival. Between 1995 and 2016 there were 149 RT. Out of them, there were 27 boys with PUV, who received 29 kidneys. Thirty patients, who received a total of 31 renal grafts due to a non-uropathic (NU) diagnosis, served as control group. Mean follow-up was 7.4 to 10.2 years.

RESULTS

There was no difference in estimated graft survival between patients with PUV and NU patients. Graft failure occurred in 23.1% of PUV patients and 34.5% patients of the NU group. There was no statistically significant disparity in graft function between the two groups. Age at transplantation and donor age were the only factors that had a significant impact on renal function. There was a higher incidence of UTI in the PUV group (96%) than in the NU group (67%). Vesicostomy was the favourable intervention in regards of graft function.

CONCLUSIONS

RT in PUV patients is successful with the same outcome as in NU patients. Bladder dysfunction may not have a major impact on graft function and graft survival. It seems that the type of pre-transplant surgical procedures may influence outcome. Therefore, these interventions -if necessary- should be limited to a minimum.

TYPE OF STUDY

Retrospective Comparative Study LEVEL OF EVIDENCE: Level III.

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.

Posterior urethral valve: Prognostic factors and renal outcome

OBJECTIVE

The aim was to study the outcome of posterior urethral valve (PUV) cases treated by stepladder protocol and the prognostic factors affecting the outcome.

MATERIALS AND METHODS

Hospital records of all PUV patients treated by stepladder protocol between January 1992 and December 2013 were reviewed. The studied parameters were: Age at presentation, serum creatinine, types of surgical intervention, vesicoureteral reflux (VUR) on initial voiding cystourethrogram (VCUG), renal cortical scars, plasma renin activity (PRA), and glomerular filtration rate (GFR).

RESULTS

Of 396 PUV patients treated during the study period, 152 satisfied study criteria. The age at presentation ranged from 2 days to 15 years (mean 31.3 months). The mean follow-up period was 5 years (range: 2-18 years). Primary endoscopic valve ablation was the most common initial procedure. Chronic renal failure was seen in 42.7% patients at the last follow-up. Serum creatinine at presentation, initial PRA levels, initial GFR, and PRA levels at last follow-up were significant predictors of final renal outcome. Age at presentation (<1 vs. >1 year), presence/absence of VUR on initial VCUG and renal cortical scars had no significant correlation with ultimate renal function.

CONCLUSION

Our study confirms the high prognostic significance of initial serum creatinine, PRA levels and GFR in cases with PUV. PRA also holds promise in long-term follow-up of these patients as a marker of progressive renal damage.

CKD and bladder problems in children

Approximately 35% of children with CKD who require renal replacement therapy have a significant urological abnormality, including posterior urethral valves, a neuropathic bladder, prune belly syndrome, Hinman syndrome, or severe vesicoureteral reflux. In such children, abnormal bladder function can have a significant deleterious effect on the renal function. In children with bladder outlet obstruction, bladder compliance and capacity often are abnormal, and a sustained intravesical pressure of >40 cm H(2)O impedes drainage from the upper urinary tract. Consequently, in these conditions, regular evaluation with renal sonography, urodynamics, urine culture, and serum chemistry needs to be performed. Pediatric urological care needs to be coordinated with pediatric nephrologists. Many boys with posterior urethral valves have severe polyuria, resulting in chronic bladder overdistension, which is termed as valve bladder. In addition to behavioral modification during the day, such patients may benefit from overnight continuous bladder drainage, which has been shown to reduce hydronephrosis and stabilize or improve renal function in most cases. In children with a neuropathic bladder, detrusor-sphincter-dyssynergia is the most likely cause for upper tract deterioration due to secondary vesicoureteral reflux, hydronephrosis, and recurrent urinary tract infection (UTI). Pharmacologic bladder management and frequent intermittent catheterization are necessary. In some cases, augmentation cystoplasty is recommended; however, this procedure has many long-term risks, including UTI, metabolic acidosis, bladder calculi, spontaneous perforation, and malignancy. Nearly half of children with prune belly syndrome require renal replacement therapy. Hinman syndrome is a rare condition with severe detrusor-sphincter discoordination that results in urinary incontinence, encopresis, poor bladder emptying, and UTI, often resulting in renal impairment. Children undergoing evaluation for renal transplantation need a thorough evaluation of the lower urinary tract, mostly including a voiding cystourethrogram and urodynamic studies.

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

OBJECTIVE

  This is a retrospective long-term evaluation of the renal allografts and bladder functions in pediatric recipients who had posterior urethral valves (PUV).

PATIENTS AND METHODS

Between March 1976 and February 2009, 2033 live-donor renal transplantations were carried out in our center. Of these, 297 (14.2%) were in the pediatric age (≤18 yr). The pediatric recipients included 20 (6.7%) boys who developed end-stage renal disease as a late complication of PUV and recognized as group I while the remaining 277 pediatric recipients were defined as group II. Demographic characteristics, post-transplant complications and graft function were compared among both groups. Patient and graft survivals of both groups were also estimated. Moreover, the bladder function of the study group was evaluated by urodynamic studies.

RESULTS

Patients with PUV (group I) were significantly younger than group II. Although the overall rate of urological complications in both groups was essentially similar, the incidence of urinary fistulae and urinary tract infection were higher in group I. The mean (SD) follow up periods for group I and II were 4.7 (4.1) and 6.4 (4.8) yr, respectively. At last follow up the serum creatinine values were similar among patients of both groups. Moreover, there were no differences in graft or patient survival at five and 10 yr. Detrusor over-activity could be elicited in only one of group I patients. Schafer nomogram showed non-obstructed pattern in all cases.

CONCLUSION

Good functional outcome could be achieved for patients with PUV if renal transplantation is necessary. Pre-transplant surgical procedures may be required such as nephroureterectomy, cytoplasty or injection of refluxing ureters. A robust anti-refluxing uretero-vesical anastomosis is important, and can be achieved by a Lich-Gregoir procedure.

Posterior urethral valve treatments and outcomes in children receiving kidney transplants

PURPOSE

We evaluated the impact of surgical approaches to posterior urethral valves on renal transplant survival and compared transplant survival in children with vs without posterior urethral valves.

MATERIALS AND METHODS

We reviewed the records of all children who underwent renal transplantation from January 1984 to March 2008 and performed univariate subgroup analysis in those with posterior urethral valves. We evaluated the ureteroneocystotomy method, immunosuppression and valve treatment. In patients with posterior urethral valves we regarded nocturnal and/or daytime incontinence, severe urgency and the need for intermittent catheterization or double voiding for increased post-void residual urine as signs of bladder dysfunction.

RESULTS

The initial renal transplant was received by 418 children at a mean age of 5.6 years. The 59 boys with posterior urethral valves received a total of 69 kidneys. By 8-year followup the kidney had failed in 24 of 59 boys with and 143 of 359 without posterior urethral valves (OR 0.9665, 95% CI 0.5462-1.692, p = 0.9105). Immunosuppression was consistent in the 2 groups. Outcomes were similar across all ureteroneocystotomy techniques. Initial management for posterior urethral valves was valve ablation alone in 12 boys, vesicostomy in 7 and supravesical diversion in 11. There was no difference in transplant survival or bladder dysfunction based on valve intervention. In 18 boys (55%) we noted overlapping signs of bladder dysfunction, of whom 11 performed intermittent catheterization or had increased post-void residual urine, 4 had severe urgency, 4 had daytime incontinence and 7 had nocturnal incontinence. Bladder dysfunction did not predict increased graft loss (OR 3.306, 95% CI 0.7615-16.27, p = 0.1134).

CONCLUSIONS

Of children who undergo renal transplantation boys with posterior urethral valves do not have a higher graft failure rate. Treatment for posterior urethral valves did not significantly impact transplant survival or bladder dysfunction.

Lower urinary tract symptoms in children and adolescents with chronic renal failure

PURPOSE

Lower urinary tract symptoms are common in children after renal transplantation. However, it is unclear whether lower urinary tract symptoms are present before transplantation or appear postoperatively. We sought to evaluate bladder function in children before renal transplantation.

MATERIALS AND METHODS

A total of 40 children 5 to 18 years old with a glomerular filtration rate of less than 50 ml per minute per 1.73 m(2) were consecutively enrolled in the study from 2006 to 2008. Bladder function was assessed by a comprehensive history, bladder diary, uroflowmetry and bladder ultrasound.

RESULTS

Of the patients 20% suffered from incontinence, 47.5% had bladder capacity larger than expected for age, 20% had discontinuous flow and 15% had residual urine 20 ml or greater. Signs consistent with bladder dysfunction (incontinence, abnormal bladder capacity, discontinuous urinary flow and/or residual urine) were observed in 13 of 13 children (100%) with urological disorders and 16 of 27 (59%) with nonurological disorders. Polyuria was present in 39% of the patients. Prior febrile urinary tract infection was significantly more common in children with vs without signs of bladder dysfunction.

CONCLUSIONS

Lower urinary tract symptoms are common in children with chronic renal failure. Screening for bladder dysfunction is important not only in children with urological disorders, but also in those with nonurological disorders, so that dysfunction can be corrected before transplantation.

Risk factors and treatment success for ureteral obstruction after pediatric renal transplantation

PURPOSE

Risk factors and treatment efficacy for ureteral obstruction following pediatric renal transplantation are poorly understood. We describe a single center experience with pediatric transplant recipients in an effort to discern risk factors and treatment efficacy.

MATERIALS AND METHODS

We retrospectively reviewed the pediatric renal transplant database at our institution from January 1984 to March 2008. Donor and recipient demographics, treatment indications, graft characteristics, surgical techniques, treatment course, complications and graft outcomes were abstracted from clinical records.

RESULTS

A total of 449 children (mean age 8.6 years) who underwent 526 renal transplants were included in the study. Ureteral obstruction requiring intervention developed in 42 cases (8%). Recipient age and gender, recipient and donor race, donor harvest technique, ureterovesical anastomosis with or without stenting, number of donor arteries, number of human leukocyte antigen mismatches, prior renal transplant and ischemia time were not significantly associated with increased incidence of ureteral obstruction. Renal failure secondary to posterior urethral valves was the only parameter significantly associated with increased incidence of ureteral obstruction (univariate OR 4.93, p = <0.0001; multivariate point estimate 7.59, p <0.0001). Of patients with ureteral obstruction 48% presented within 100 days after transplant. Kaplan-Meier analysis showed significantly decreased ureteral obstruction-free survival in patients with vs without posterior urethral valves (log rank test, p <0.0001). Ureteral obstruction, stenting and dilation were not significantly associated with increased graft loss or patient death.

CONCLUSIONS

Ureteral obstruction after renal transplantation in children is a challenging complication that demands clinical vigilance. Posterior urethral valves appear to be a significant risk factor for post-transplant ureteral obstruction likely due to local factors such as ischemia, thick bladder wall and collagen remodeling.

Prenatal urinary matrix metalloproteinase profiling as a potential diagnostic tool in fetal obstructive uropathy

BACKGROUND/PURPOSE

The diagnostic evaluation, patient stratification, and prenatal counseling for congenital obstructive uropathy remain sub-optimal. Matrix metalloproteinase (MMP) expression profiles are emerging as a valuable diagnostic tool in assorted disease processes. We sought to determine whether congenital obstructive uropathy impacts MMP expression in fetal urine.

METHODS

Fetal lambs (n = 25) were divided in two groups: group I (n = 12) underwent a sham operation and group II (n = 13) underwent creation of a complete urinary tract obstruction. Gelatin zymography panels for 4 MMP species were performed on fetal urine in both groups at comparable times post-operatively. Statistical analysis was by the Fisher's exact test (P < .05).

RESULTS

Overall fetal survival was 80% (20/25). A variety of significant differences in MMP expression between the two groups were identified. The following profiles were present only in obstructed animals: any MMP other than MMP-2 (P = .029), including any MMP other than 63 kDa and 65 kDa (P = .009); 2 or more MMPs excluding MMP-2s (0.029); and 3 or more MMPs (P = .029).

CONCLUSIONS

Limited matrix metalloproteinase expression is present in the urine of normal ovine fetuses. Fetal obstructive uropathy impacts urinary MMP expression in various distinguishable patterns. Prenatal urinary MMP profiling may become a practical and valuable diagnostic tool in the evaluation of congenital obstructive uropathy.

Strategies to treat children with end-stage renal dysfunction and severe lower urinary tract anomalies for receiving a kidney transplant

Dealing with children with bladder dysfunction and kidney transplant is certainly not a new issue. Nevertheless, it is still a matter of discussion and dilemma, based on few, not standardized, institutional center experiences. The authors perform a review of the techniques employed to restore the bladder condition in terms of storage and drainage of urine to receive a kidney transplant in a safer condition. Aspects of the etiology and the way of evaluation of such a group of patients are discussed. The strategies and individualized therapeutic options are presented and compared with the author's experience based upon 25 children with urinary anomalies who received 28 kidney transplants. Nevertheless, the number of complications, mainly UTI, graft and patient survival rates are equivalent to the group of children with non-urological causes of ESRD. Patients with severe lower urinary tract abnormalities and ESRD may receive a kidney transplant with comparable success.

Kidney transplantation in children with posterior urethral valves

There is controversy about the outcome of renal transplantation in patients with PUV. The objective of this study was to analyze the outcome of renal transplantation in children with PUV. Fifteen patients had a history of PUV as the etiology of their ESRD. Forty-five patients comprised a control group without lower urinary tract anomalies. Mean age and follow-up duration were not significantly different between the case and the control group (p = 0.1). The immunosuppressive protocol and the year of transplantation were similar in these two groups (p = 0.2, 0.4, respectively). Among patients with PUV, 37.5% had acute rejection; and 56.2% had chronic rejection. Among the controls, 22.2% had acute rejection and 28.8% had chronic rejection. None of these differences was significant. Mean survival time was seven yr in affected patients and 6.2 yr in the control group (p = 0.9). Among patients with PUV, the rate of graft survival in the first year after transplantation was 95%; and those in the third, fifth, and seventh yr, 91%, 65%, and 50%, respectively. For the controls, the graft survival was 83% at one yr; 80% at three yr; 71% at five yr; and 60% at seven yr after transplantation (p = 0.9). Conclusively, this study showed that a history of PUV had no effect on graft function. Graft survival was not different among these patients compared with patients free of these anomalies. We also showed that urological complications were few in these patients.

Renal transplantation or bladder augmentation first? A comparison of complications and outcomes in children

OBJECTIVE

To identify whether the order of performing transplant and bladder reconstruction operations in children who need both operations affects outcome of either operation.

PATIENTS AND METHODS

A retrospective case note review was performed of children identified from our database, who had undergone both renal transplantation and bladder augmentation between 1990 and 2005.

RESULTS

In all, 18 renal transplants (eight live-related) were performed in 16 children with 10 transplants done after bladder augmentation and eight transplants done before augmentation. The median age at transplantation was 7.5 years and at augmentation was 7.0 years. The median interval between the operations was 33.5 months and the median follow-up was 58.4 months after transplantation. Outcomes were compared between the two groups of patients: those who received their transplantation before bladder augmentation, and those who were transplanted after bladder augmentation. There was no difference between these groups in: the pre- transplant estimated glomerular filtration rate, inpatient stay after transplantation or after augmentation, and incidence of urinary tract infection in the 3 months after renal transplantation or after bladder augmentation. There was no statistical difference in renal allograft loss with one graft failure in the group who were augmented first, and four graft failures in the group who were transplanted first. However, it is of note that the single graft failure in the patient augmented first was due to renal artery thrombosis on the first day related to a double arterial anastomosis, whilst in the other group, three of the graft failures were in transplants that had initially been drained by ureterostomy. Three patients in the group transplanted first developed significant ureteric pathology, of which one developed graft failure.

CONCLUSION

Bladder reconstruction can be performed safely before transplantation; it does not increase complications and might better protect the renal graft and specifically the transplant ureter.

Increased urologic complications in children after kidney transplants for obstructive and reflux uropathy

In the cyclosporine era, reports on pediatric kidney transplant (KTx) patients with obstructive and reflux uropathy are limited by small numbers, short follow-up, and/or lack of control groups. Our single-center study evaluated long-term outcomes (patient and graft survival, urinary tract infections [UTIs], urologic complications) in a large cohort of KTx recipients (<20 years old). We matched our 117 study patients with obstructive and reflux uropathy with 117 controls whose KTx was needed for other reasons; all 234 underwent their KTx between April 25, 1984, and October 23, 2002. The mean age was 8.0 +/- 6.2 years; mean follow-up, 133 +/- 67 months. The urologic complication rate was higher in study patients (43%) than in controls (11%) (p < 0.0001), as was the UTI rate (45% vs. 2%; p < 0.0001). The metabolic acidosis and UTI rates were higher in study patients who did (vs. did not) undergo bladder augmentation (p < 0.0001). We found no significant difference between study patients and controls in patient or graft survival, acute or chronic rejection, or mean estimated glomerular filtration rates. Unique to our study is the finding of higher metabolic acidosis and UTI rates in study patients who underwent bladder augmentation.

Does bladder augmentation stabilize serum creatinine in urethral valve disease? A series of 19 cases

OBJECTIVE

This study evaluates the results of bladder augmentation (BA) in 19 boys with posterior urethral valves, especially as regards its efficacy in stabilizing serum creatinine.

PATIENTS AND METHODS

In the period 1995-2005, 188 patients with urethral valves were surgically managed. Nineteen of these had undergone BA as a part of their surgical management after initial endoscopic valve ablation in 15 and diversion in four boys. The mean serum creatinine at the time of BA was 2.11 mg/dl.

RESULTS

BA stabilized the serum creatinine in 14 but failed to do so in five boys. A serum creatinine level of more than 2mg/dl at the time of BA was associated with a significantly worse rate of success. BA as part of an undiversion procedure in three boys was unsuccessful.

CONCLUSION

In an economic milieu where renal transplantation is not available for the majority of deserving children, careful selection is required before BA is considered as a surgical solution for the valve bladder. BA, when otherwise indicated, has been beneficial in children with pre-augmentation creatinine up to 2 mg/dl.

Kidney transplants in patients with bladder augmentation: correlation and evolution

OBJECTIVE

To review the literature, analyse the evolution of kidney transplants (KT) in patients with bladder augmentation (BA) and investigate the relation between BA and KT.

MATERIALS AND METHODS

Six patients with a history of severe lower urinary tract dysfunction and BA, received a KT at our Unit between 1993 and 2003. Three had moderate renal failure at the moment of the BA. The remaining three had end stage renal failure.

RESULTS

With a follow-up of 7 years (mean) we have a patient survival of 100% and a graft survival of 83%. No complications occurred between the BA and the KT. The few KT complications were not related to BA.

CONCLUSION

When a bladder dysfunction is present, it should be treated before KT. In noncompliant bladders, BA is the best treatment. This can be done to try to avoid end stage renal failure or only to prepare the lower urinary tract for reception of the transplant. The presence of a BA did not worsen the evolution of the KT.

How does the presence of urologic problems change the outcome of kidney transplantation in the pediatric age group

PURPOSE

We retrospectively reviewed the impact of functional and anatomic urologic disorders on kidney transplantation outcomes in terms of the surgical and long-term results of pediatric renal transplantation.

MATERIALS AND METHODS

Of the 55 kidney transplantations in the pediatric age group, end-stage renal disease (ESRD) was secondary to genitourinary disorders in 23 patients (42%). The urologic abnormalities were vesicoureteral reflux in 13 patients (59%), neurogenic bladder in 4 patients (18%), posterior urethral valves in 3 patients (14%), renal stone disease in 4 patients (18%), bilateral ureterovesical junction obstruction in 3 patients (14%), and unilateral renal agenesis with concomitant contralateral ureteropelvic junction obstruction in 1 patient (4%).

RESULTS

Of the 23 patients with urologic problems, 19 (83%) had functioning grafts with a mean follow-up of 49 months (range, 7-120 months). In the other 32 patients, 26 (81%) had functioning grafts with a mean follow-up of 43 months (range, 1-144 months). The graft survival, mean serum creatinine, and urinary tract infection rates of the patients did not differ between the two groups.

CONCLUSIONS

The presence of functional urologic disorders as the cause of ESRD did not seem to change the outcome of renal transplantation in terms of graft survival when compared with patients without any urologic disorders. Urinary tract infections seem to be a little more common and yet clinically not significant in those patients. Reflux does not always need to be corrected before transplantation, unless it is causing symptoms or infection.

Renal transplantation in children with posterior urethral valves

The objective of this study was to analyze whether renal transplantation (RT) in children with posterior urethral valves (PUV) constitutes a special group with respect to groups with different etiologies of end-stage renal disease (ESRD). Between 1979 and 2004, 22 RT were performed in 19 children with PUV. The median age at RT was 10 years (range: 1.3-17). Immunosuppression was provided by triple therapy and polyclonal/monoclonal antibodies. This group was compared with the two control groups: (1) glomerulopathy (n=62) and (2) pyelonephritis/dysplasia (n=42) without lower urinary tract disease, transplanted in the same period. Ten graft losses occurred in 22 transplants: thrombosis (2), acute rejection (3), chronic graft nephropathy (2), and death of patients (3) with a functioning graft in the 1st postoperative month. We did not find significant differences versus the control group in renal function or probability of graft or patient survival at 1, 5, and 10 years. We observed a greater risk of urological complication in patients with PUV. RT with PUV constitutes a special group due to the compulsory young age and the need for careful and complex medicosurgical management; nevertheless, the results achieved were similar to those obtained in our general RT population.

Outcome of renal transplantation in children with low urinary tract abnormality

INTRODUCTION

Patients with end-stage renal disease and lower urinary tract abnormality are often considered high risk for renal transplantation.

METHODS AND SUBJECTS

To examine the degree of risk, we studied patients who received renal transplants between 1985 and 2003. Forty eight patients had congenital lower urinary tract anomalies and 168 patients comprised a control group without these anomalies.

RESULTS

Mean age and distribution of sex were not significantly different between the case and the control group. Among patients with anomalies, 8% had delayed graft function; 75%, acute rejection; and 39.5%, chronic rejection. Among the controls 2.3% had delayed graft function; 59%, acute rejection; and 35%, chronic rejection. None of these differences was significant. Mean survival time was 6 years in affected patients and 7.3 years in the control group (P = .7). Among patients with anomalies the rate of graft survival in the first year after transplantation was 90%; and those in the third, fifth, and seventh years, 76%, 65%, and 40%, respectively. For the controls, the graft survivals were 88% at 1 year; 73% at 3 years; 70% at 5 years; and 49% at 7 years after transplantation.

CONCLUSION

This study showed that a history of lower urinary tract anomalies had no effect on graft function. Graft survival was not different among these patients compared with patients free of these anomalies.

Obstructive uropathy

Routine second trimester ultrasound screening has resulted in more infants diagnosed with antenatal hydronephrosis. Current recommendations suggest postnatal evaluation of all infants with a renal pelvic diameter >5 mm with ultrasound and voiding cystourethrogram (VCUG.) There are many etiologies of obstructive uropathy including ureteropelvic junction (UPJ) obstruction, ureterovesical junction (UVJ) obstruction, posterior urethral valves (PUV), prune belly syndrome, and vesicoureteral reflux (VUR). Obstructive uropathy can result in tubular damage and decreased nephron number. Tubular damage can result in sodium wasting, hyperkalemic acidosis, and nephrogenic diabetes insipidus. Most patients do not require renal replacement therapy in the neonatal period; however, chronic renal insufficiency can occur if the neonate has a significant reduction in nephron number or progressive renal damage from obstruction or infection.

Kidney transplantation in children: a 50-case experience

OBJECTIVES

The aim of this article was to report our experience with kidney transplantation in children.

MATERIALS AND METHODS

From June 1980 to December 2003, 690 kidney transplants were performed in our institution, among which 50 were in patients with less than 18 years old. Technical aspects as well as clinical and surgical evolution were reviewed in this study.

RESULTS

Patient's mean age was 12 years (2-17 years). Twenty-nine patients were male and 21 female. Live related donors were responsible for 75% of the cases (38 patients) and 25% (12 patients) came from cadaver donors. The main complications were ureteral fistula in 6 patients (12%), arterial stenosis in 2 (4%), wall infection and dehiscence in 1 case (2%). The overall rate of surgical complication was 20%. No case of hyperacute rejection was reported. During the follow-up 20 grafts were lost due to chronic rejection and 2 patients died. No loss of graft due to surgical complications was reported. The graft survival rate was 71% in 1 year, 64% in 3 years and 57% in 5-year follow-up.

CONCLUSIONS

Kidney transplantation in children is a viable treatment option for terminal kidney disease presenting success and surgical complication rate similar to kidney transplantation in adults.

Pediatric renal transplantation and the dysfunctional bladder

We retrospectively reviewed our long-term experience with pediatric renal transplantation into a dysfunctional lower urinary tract to evaluate graft survival, function, and special urological complications. Between 1967 and March 2000, a total of 349 renal transplantations were performed in children younger than 18 years. Malformations of the lower urinary tract were the reasons for end-stage renal failure in 66 children (18.6%). The cause of urinary tract disorders included: meningomyelocele connected with neuropathic bladder (n = 4 transplantations); prune belly syndrome (n = 5 transplantations); VATER association (n = 2 transplantations); posterior urethral valves (n = 27 transplantations); and vesico-uretero-renal reflux (n = 28 transplantations). The majority of the patients underwent surgical interventions to preserve renal function or to prepare renal transplantation. The 1- and 5-year graft survival rate was evaluated with special reference to the underlying disease. The 1-year graft survival rate in all children with lower urinary tract malformations was 83.3%, compared with 88% for all children. In those children with vesico-ureteral reflux, it was 92.8% and in the children with Vater association and prune belly syndrome, it was 85.7%. One graft was lost in the children who had neurogenic bladder, so the 1-year graft survival rate was 75%. The worst 1-year graft survival rate was obtained for boys who had posterior urethral valves (1-year graft survival rate: 74%; 5-year graft survival rate: 62.9%). Concerning the 5-year graft survival rate, it was 70% for all children with malformations of the urinary tract. The best rate was obtained for children with reflux in the native kidneys (78.5%), followed by those with VATER association and prune belly syndrome. As an additional child with neurogenic bladder lost his graft, the 5-year graft survival rate was 50%. Pediatric renal transplantation into a dysfunctional bladder can be connected with high urological complication rates which may contribute to worse graft survival. The 1- and 5-year graft survival rate in children with malformations of the lower urinary tract is worse than in children without bladder dysfunction. We regarded a striking difference between graft survival and the urological disorders which led to renal insufficiency. We obtained the worst graft survival rates in children with posterior urethral valves which are usually connected with bladder emptying problems and dysfunctional voiding. Potential pediatric transplant recipients must be classified according to pathophysiological as well as anatomical abnormalities of the urinary tract and all urological problems have to be solved prior to transplantation. At our center, living donors are favored to plan transplantation of these children properly.