Kidney transplantation before or after augmentation cystoplasty in children with high-pressure neurogenic bladder

A systematic review of kidney transplantation outcomes in patients with end-stage renal disease due to childhood lower urinary tract malformations

PURPOSE

Patients with lower urinary tract malformations (LUTM) were suspended from kidney transplantation (KT) programs in the past due to various concerns. Consequently, only a limited number of studies have explored this topic at hand. In this study, our objective was to perform a systematic review (SR) to evaluate the current evidence regarding KT outcomes as well as patient survival (PS), postoperative complications and urinary tract infections (UTI) in individuals with childhood LUTM.

METHODS

The search encompassed databases of Web of Science, Medline (via PubMed), and Embase (via Scopus) to identify all studies reporting outcomes on KT for patients with LUTM. The research included articles published in English from January 1995 till September 2023.

RESULTS

Of the 2634 yielded articles, 15 met the inclusion criteria, enrolling a total of 284,866 KT patients. There was significantly better 5-year graft survival (GS) in recipients with LUTM compared to the control group (RR, 1.04; 95% CI 1.02-1.06); while GS at 1-year and 10-year, and PS at 1-year, 5-year and 10-year were similar between groups. On the other hand, the postoperative UTI rate was significantly higher in the LUTM group (RR: 4.46; 95% CI 1.89-10.51). However, data on serum creatinine and estimated glomerular filtration rate on follow-up were insufficient.

CONCLUSION

GS and PS rates appear to be similar in patients with childhood LUTM and those with normal lower urinary tract functions. Despite a higher postoperative UTI rate within this patient group, it appears that this has no effect on GS rates.

[Kidney transplantation in children with complex urogenital malformations-what should be considered?]

BACKGROUND

Congenital anomalies of the kidneys and urinary tract (CAKUT) are the most common cause of end-stage renal disease (ESRD) in children. Approximately one third of children with CAKUT have lower urinary tract dysfunction (LUTD).

AIM

This article highlights the important aspects that need to be considered in kidney transplantation of children with complex urogenital malformations.

MATERIALS AND METHODS

The paper reviews the existing literature regarding the evaluation, preparation, perioperative management, and follow-up of children with complex urogenital malformations and ESRD undergoing renal transplantation.

RESULTS

Comprehensive diagnostics are required before any pediatric kidney transplantation. If LUTD is suspected, voiding cystourethrography and a urodynamic examination should be performed. Treatment of symptomatic vesicoureterorenal reflux and LUTD is mandatory prior to pediatric kidney transplantation. Following successful kidney transplantation of children with congenital urogenital malformations, lifelong follow-up is required. Regular reevaluations of the bladder by means of urodynamic examinations are necessary. In patients following bladder augmentation with intestinal segments or urinary diversions in childhood, regular endoscopic examinations of the urinary tract are recommended to rule out secondary malignancy.

CONCLUSION

Treatment of children with complex urogenital malformations should be carried out in centers with appropriate expertise.

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.

Pearls and Pitfalls in Pediatric Kidney Transplantation After 5 Decades

Worldwide, over 1,300 pediatric kidney transplantations are performed every year. Since the first transplantation in 1959, healthcare has evolved dramatically. Pre-emptive transplantations with grafts from living donors have become more common. Despite a subsequent improvement in graft survival, there are still challenges to face. This study attempts to summarize how our understanding of pediatric kidney transplantation has developed and improved since its beginnings, whilst also highlighting those areas where future research should concentrate in order to help resolve as yet unanswered questions. Existing literature was compared to our own data of 411 single-center pediatric kidney transplantations between 1968 and 2020, in order to find discrepancies and allow identification of future challenges. Important issues for future care are innovations in immunosuppressive medication, improving medication adherence, careful donor selection with regard to characteristics of both donor and recipient, improvement of surgical techniques and increased attention for lower urinary tract dysfunction and voiding behavior in all patients.

Surgical considerations in paediatric kidney transplantation: an update

Background

Kidney transplantation has established itself as the most appropriate mode of renal replacement therapy for the majority with end-stage kidney disease. Although at present this is applicable for children as well as adults, a few decades back kidney transplantation was not considered a first-line option in children. This was due to inferior outcomes following transplantation in this age group compared to that of adults. These poor results were attributed to challenges in paediatric transplantation such as the shortage of suitable donors, technical difficulties in performing a sound vascular anastomosis and the adverse effects of immunosuppressive medication on growth and development. However, current patient and graft-centred outcomes after paediatric transplantation equal or surpass that of adults. The advances in evaluation and management of specific surgical concerns in children who undergo transplantation, such as pre-transplant native nephrectomy, correction of congenital anomalies of the urinary tract, placement of an adult-sized kidney in a small child and minimizing the risk of allograft thrombosis, have contributed immensely for these remarkable outcomes.

Conclusions

In this review, we aim to discuss surgical factors that can be considered unique for children undergoing kidney transplantation. We believe that an updated knowledge on these issues will be invaluable for transplant clinicians, who are dealing with paediatric kidney transplantation.

Safety of augmentation cystoplasty in patients with bladder abnormalities undergoing renal transplantation: a systematic review

BACKGROUND Augmentation cystoplasty (AC) has been recently proposed to improve a bladder condition before or after a renal transplantation for an optimal allograft function. Until now, AC in adults with end-stage renal disease (ESRD) is uncommon and rarely practiced. This study aimed to investigate the safety of AC in patients with bladder abnormalities who required renal transplantation. METHODS Studies of patients with ESRD and abnormal bladder who underwent AC were searched in ProQuest, PubMed, EBSCO, and Cochrane Library online databases. Only studies published in English from January 1985 to May 2020 were included. The keywords used were renal transplantation, bladder dysfunction, cystoplasty, and their synonyms. Data were extracted by two independent authors who selected, screened, and assessed the articles’ eligibility and quality. The outcomes were graft survival rate and complications of AC. RESULTS A total of 19 articles were included. AC improved an intravesical pressure, a bladder capacity, and a compliance in patients with ESRD and bladder abnormalities, allowing patients to undergo the renal transplantation. Even though AC in patients with renal transplantation resulted in a significantly higher urinary tract infection rate than patients who underwent renal transplantation only, performing AC after renal transplantation was considered safe. CONCLUSIONS AC was considered safe for patients with bladder abnormalities who underwent 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.

Urologic issues in pediatric transplant recipients

The limited supply of kidneys for pediatric transplantation leads to a large number of children in waiting transplant list. These patients have to be properly evaluated and prepared before organ transplantation to increase its success. The aim of this review is focus on urologic issues of pediatric kidney transplants such as preoperative evaluation and urinary tract abnormalities correction, surgical technique, and postoperative complications. All children that are candidates for kidney transplantation should be submitted to abdominal ultrasound. If bladder dysfunction is suspected, a more detailed evaluation is mandatory, including a voiding cystourethrography and urodynamic study. Patients with a poor bladder capacity and compliance will require bladder augmentation. Whenever possible the native ureter is recommended for that. Regarding kidney transplantation, recipient surgery can be safely performed through an extraperitoneal access, even in children weighting less than 10 kilograms. It allows adequate access to iliac vessels, aorta and vena cava. Graft survival continued to improve over the past decade and it is around 80% in 5 years. Postoperative complications such as urinary fistula may occur in less than 5% of cases, while vascular complications are reported in 1% to 2% of cases.

Long-term Outcome of 1-step Kidney Transplantation and Bladder Augmentation Procedure in Pediatric Patients

BACKGROUND

Guidelines for bladder augmentation (BA) in kidney transplantation (KT) recipients are not well-defined. In our center, simultaneous BA with KT (BA-KT) is performed. We assessed transplantation outcomes of this unique extensive procedure.

METHODS

A case-control single center retrospective study. Transplantation outcomes were compared with those of KT recipients who did not need BA.

RESULTS

Compared with 22 patients who underwent KT only, for 9 who underwent BA-KT, surgical complications and the need for revision in the early posttransplantation period were similar; early graft function was better: estimated glomerular filtration rate, 96.5 ± 17.1 versus 79.4 ± 16.6 mL/min at 0 to 6 months (P = 0.02); posttransplantation clean intermittent catheterization was more often needed: by 78% (7/9) versus 13% (3/22); and asymptomatic bacteriuria was more common: 100% versus 9% during the first 6 months (P < 0.001), 55% versus 9% (P = 0.02) and 66.6% versus 9% during the first and second years, respectively (P = 0.004). Urinary tract infection (UTI) incidence was also higher: 100% versus 23% during the first 6 months and 44% versus 9% during the second year posttransplantation. Graft function deteriorated significantly in the BA-KT group by the fifth posttransplantation year: estimated glomerular filtration rate was 47.7 ± 39.7 mL/min versus 69 ± 21.3 mL/min, with only 6 (66%) of 9 functioning grafts versus 100% in the KT only group. Causes of graft loss were noncompliance with drug therapy in 2 patients and recurrent UTIs in 2 patients.

CONCLUSIONS

Excellent short-term outcome for simultaneous BA-KT is threatened by graft loss due to a high prevalence of UTIs and patient noncompliance with the demanding complex posttransplantation therapy.

Renal Transplant in Abnormal Bladder: Treatment Options and Their Effects on Graft Outcome

OBJECTIVES

Correction of structural urologic disorders and optimization of emptying and storage function of the bladder should be achieved before renal transplant in patients with abnormal urinary bladders to protect the new transplanted kidney. The aim of this study was to determine the outcomes of renal transplant among the differently treated abnormal bladder patients.

MATERIALS AND METHODS

This was a retrospective study of 30 renal transplant recipients with abnormal bladders who were divided into 2 groups based on abnormal bladder management. Group A included 12 patients who required surgical procedures for their bladder, including 6 with augmentation cystoplasty, 1 with Mitrofanoff procedure, 2 with ileal conduit, 1 with vesicostomy, and 2 who required artificial urinary sphincter. Group B included 18 patients who were treated with oral anticholinergics or beta-3 sympathomimetic drugs, clean intermittent catheterization, suprapubic catheterization, or a combination of these options. Graft function, survival, and complications were compared between both groups.

RESULTS

Mean estimated glomerular filtration rates at 1, 3, and 5 years were higher in group A than in group B but not statistically significant. We also found no significant differences in graft survival between the 2 groups. Among all postoperative complications, only incidence of wound infection was significantly higher in group A than in group B (33% vs 5%; P = .04).

CONCLUSIONS

The options of abnormal bladder treatment (either by surgical procedures or other methods of treatment) did not have an impact on graft outcome after renal transplant as long as a safe and suitable bladder was achieved.

Bladder dysfunction following renal transplantation is it predictable?

Dysfunction of the urinary bladder is often faced in kidney transplantation due to various structural, neurological, infectious, or other pathologies. As the goal is to obtain a well functioning urinary bladder or at least, a low-pressure reservoir without reflux, specific urologic examinations and therapies should be performed. This review based on a Medline and PubMed search as well as on international guidelines and personal experience, reflects the actual knowledge in the field of pretransplant urologic evaluation as well as pre- and posttransplant optimal therapeutic options. The evaluation of these factors and interventional strategies will help to improve long-term transplant outcomes.