Renal transplantation in children with abnormal lower urinary tract

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.

Paediatric kidney transplantation in under-resourced regions-a panoramic view

Kidney transplantation is the ideal choice of kidney replacement therapy in children as it offers a low risk of mortality and a better quality of life. A wide variance in the access to kidney replacement therapies exists across the world with only 21% of low- and low-middle income countries (LLMIC) undertaking kidney transplantation. Pediatric kidney transplantation rates in these under-resourced regions are reported to be as low as < 4 pmcp [per million child population]. A robust kidney failure care program forms the cornerstone of a transplant program. Even the smallest transplant program entails a multidisciplinary workforce and expertise besides ensuring family commitment towards long-term care and economic burden. In general, the short-term graft survival rates from under-resourced regions are comparable to most high-income countries (HIC) and the challenge lies in the long-term outcomes. This review focuses on specific issues relevant to kidney transplants in children in under-resourced regions by highlighting limitations in the capacity and health workforce, regulatory norms, medical issues, economic burden, factors beyond financial hardship and ethical considerations relevant to these regions. Finally, the perspective of strengthening transplant programs in these regions should factor in the bigger challenges that exist in achieving the health-related sustainable development goals by 2030.

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.

Long-term outcome of transplant ureterostomy in children: A National Review

BACKGROUND

CAKUT are the most common cause of end-stage renal failure in children (Pediatr Nephrol. 24, 2009, 1719). Many children with CAKUT have poor urinary drainage which can compromise post-transplant outcome. Identifying safe ways to manage anatomical abnormalities and provide effective urinary drainage is key to transplant success. Much debate exists regarding optimum urinary diversion techniques. The definitive formation of a continent urinary diversion is always preferable but may not always be possible. We explore the role of ureterostomy formation at transplantation in a complex pediatric group.

METHODS

We report six pediatric patients who had ureterostomy formation at the time of transplantation at the National Paediatric Transplant Centre in Dublin, Ireland. We compared renal function and burden of urinary tract infection to a group with alternative urinary diversion procedures and a group with normal bladders over a 5-year period.

RESULTS

There was no demonstrable difference in estimated glomerular filtration rate between the groups at 5-year follow-up. The overall burden of UTI was low and similar in frequency between the three groups.

CONCLUSIONS

Ureterostomy formation is a safe and effective option for temporary urinary diversion in children with complex abdominal anatomy facilitating transplantation; it is, however, important to consider the implications and risk of ureterostomy for definitive surgery after transplantation.

Does renal transplant in children with LUTD improve their bladder function?

Much is still unknown about LUT function after receiving renal graft. Graft function was the main focus of different studies discussing the same issue. However, these studies ignored the effects of the graft on lower tract function and more demand for bladder cycling and growth of the child. Therefore, we aimed at evaluating the LUT function after RT into patients with LUTD. We enrolled a retrospective cohort of 83 live renal transplant children with LUTD. The 44 patients in Group (A) had a defunctionalized bladder, and the 39 patients in Group (B) had underlying LUT pathology. All patients had clinical and urodynamic evaluation of LUT functions at least 1 year after RT. We found that the improvement in patients with impaired bladder compliance was 73% in Group (A) and 60% in Group (B), with no statistically significant difference between the study groups. In Group (B), there was statistically significant worsening of MFP (8.4%) and mean PVR (79.9%) after RT. In Group (A), mild but stable significant improvement of all clinical and urodynamic parameters was observed. Serum creatinine was significantly worse in patients with pathological LUTD compared with those with defunctionalized bladder but without significant effect on graft survival. All LUT variables seemed to have no adverse effect on graft survival except for use of CIC and augmented bladder. Incident UTI independent of LUT variables accounted for 20% of graft creatinine change.

Favorable Outcomes of Renal Transplant in Children With Abnormal Lower Urinary Tract

OBJECTIVES

Chronic kidney disease caused by lower urinary tract abnormalities is a significant complication in pediatric care. Although there are conflicting reports about clinical outcomes in the past, favorable outcomes have been reported in recent years. Despite this, many centers still refrain from performing renal transplant in these patients. Here, we compared clinical outcomes of renal transplant recipients with and without lower urinary tract abnormalities.

MATERIALS AND METHODS

Our study included 71 renal transplant recipients who were divided into 3 groups: 17 patients with abnormal lower urinary tracts having vesicoureteral reflux (group 1), 7 patients with abnormal lower urinary tracts having bladder dysfunction (group 2), and 47 patients with anatomically and functionally normal lower urinary tracts (group 3). We retrospectively compared demographic features, clinical course, graft survival, pre- and posttransplant incidence of urinary tract infections, and final graft function among the groups.

RESULTS

There were no statistically significant differences among groups regarding median age at time of transplant, graft survival, median creatinine level, and median glomerular filtration rate (P > .05). Significant differences were shown in incidence of urinary tract infections between patients in groups 1 and 2 (abnormal lower urinary tracts) and group 3 (normal lower urinary tracts) before transplant (P < .05). Although frequency of urinary tract infections in groups 1 and 2 were moderately higher than shown in group 3 after transplant, this difference was not statistically significant.

CONCLUSIONS

Although the children with abnormal lower urinary tracts had slightly higher incidence of urinary tract infections, there were no differences between patients with abnormal and normal lower urinary tracts regarding allograft survival and function. In addition, proper follow-up of patients before and after transplant, based on our experience, should include educating patients and their parents about potential complications after transplant for the best outcome of renal transplant.

Outcomes of living donor renal transplantation in children with lower urinary tract dysfunction: a comparative retrospective study

OBJECTIVES

To compare outcomes of renal transplantation (RTx) in children with end-stage renal disease (ESRD) resulting from lower urinary tract dysfunction (LUTD) vs other causes.

PATIENTS AND METHODS

A database of children (<18 years old) who underwent RTx between May 2008 and April 2012 was reviewed. Patients were divided into those with LUTD (group A, n = 29) and those with other causes of ESRD (group B, n = 74). RTx was performed after achieving low intravesical pressure (<30 cmH2 O) with adequate bladder capacity and drainage. The groups were compared using Student's t-test, Mann-Whitney, chi-squared or exact tests. Graft survival rates (GSRs) were evaluated using Kaplan-Meier curves and the log-rank test.

RESULTS

The mean ± sd (range) age of the study cohort was 5.05 ± 12.4 (2.2-18) years. Causes of LUTD were posterior urethral valve (PUV; 41.4%), vesico-ureteric reflux (VUR; 37.9%), neurogenic bladder (10.3%), prune belly syndrome (3.4%), obstructive megaureter (3.4%) and urethral stricture disease (3.4%). There was no significant difference in age, dialysis duration or donor type. In group A, 25 of the 29 patients (86.2%) underwent ≥1 surgery to optimize the urinary tract for allograft. Pretransplant nephrectomy was performed in 15 of the 29 patients (51.7%), PUV ablation in nine patients (31%) and ileocystoplasty in four patients (13.7%). The mean ± sd follow-up was 4.52 ± 1.55 and 4.07 ± 1.27 years in groups A and B, respectively. There was no significant difference in creatinine and eGFR between the groups at different points of follow-up. The GSRs at the end of the study were 93.1 and 91.1% in groups A and B, respectively (P = 1.00). According to Kaplan-Meier survival curves, there was no significant difference in the GSR between the groups using the log-rank test (P = 0.503). No graft was lost as a result of urological complications. In group B, one child died from septicaemia. The rate of urinary tract infections was 24 and 12% in groups A and B, respectively, but was not significant. No significant difference was found between the groups with regard to the incidence of post-transplantation hydronephrosis. Of the 22 patients who had hydronephrosis after transplantation, three were complicated by UTI. Injection of bulking agents was required in two patients for treatment of grade 3 VUR. In the third patient, augmentation cystoplasty was needed.

CONCLUSION

Acceptable graft function, survival and UTI rates can be achieved in children with ESRD attributable to LUTD. Thorough assessment and optimization of LUT, together with close follow-up, are key for successful RTx.

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.

Non-viral infections in children after renal transplantation

Renal transplantation has long been recognised as the gold standard treatment for children with end-stage renal failure. There has been an improvement over the years in patient and renal allograft survival because of improved immunosuppression, surgical techniques and living kidney donation. Despite reduced acute allograft rejection rates, non-viral infections continue to be a serious complication for paediatric renal transplant recipients (RTR). The risk of infections in RTR is determined by the pre-transplantation immunisation status, post-transplant exposure to potential pathogens and the amount of immunosuppression. The greatest risk of life-threatening and Cytomegalovirus infections is during the first 6 months post-transplant owing to a high immunosuppressive burden. The potential sources of bacterial infections are donor derived, transplant medium fluid, peritoneal and haemodialysis catheter and transplant ureteric stent. Urinary tract infections are frequent in patients with lower urinary tract dysfunction and can result in renal allograft damage. This review outlines the incidence, timing, risk factors, prevention and treatment of non-viral infections in paediatric RTR by critically reviewing current immunosuppressive regimens, their risk-benefit ratio in order to optimise renal allograft survival with reduced rates of rejection and infectious complications.

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.

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.

Long-term outcome after renal transplantation in childhood

The purpose of this article is to review: 1. Factors influencing long-term outcome data after transplantation 2. Patient survival overall, the effect of recipient age and donor type, causes of death, comparison of mortality after transplantation with that on dialysis, and effect of pre-emptive transplantation and race 3. Transplant survival overall, and the effect of recipient and donor age, donor type, pre-emptive transplantation, recurrent diseases, human leukocyte antigen (HLA) matching, immunosuppression, concordance, hypertension, bladder dynamics and type of donor nephrectomy 4. Final height and obesity 5. Psycho-social outcome.

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.

Kidney Transplantation in Children With Augmentation Cystoplasty

PURPOSE

Treatment of children with end stage renal disease, especially those with significant bladder dysfunction, is difficult. A high pressure and low capacity bladder is a major risk factor for a transplanted kidney. Cystoplasty can protect the kidney allograft by reducing the intravesical pressure and creating an appropriate capacity. The aim of this study was to evaluate the outcome of kidney transplantation in children with and without prior cystoplasty.

MATERIALS AND METHODS

A total of 43 children with bladder dysfunction in urgent need of cystoplasty were enrolled in the study and were compared to a control group with regard to acute and chronic rejection rates, survival of the transplanted kidney, surgical complications and febrile urinary tract infection.

RESULTS

The rates of febrile urinary tract infection and chronic rejection were significantly higher in patients with prior cystoplasty (p<0.001 and p=0.004, respectively). Also, graft loss was much more frequent in these patients (34.9% vs 20.9%), although this difference was not statistically significant. In patients with prior cystoplasty graft survival rates were 92%, 73%, 58% and 45% at postoperative years 1, 3, 5 and 7, respectively. In the control group these rates were 94%, 87%, 81% and 75%, respectively (p=0.007).

CONCLUSIONS

Based on our findings, the survival rate of the kidney is significantly lower in children with prior cystoplasty, possibly due to the higher prevalence of chronic rejection and febrile urinary tract infection in this group.

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.