Endoscopic treatment of symptomatic refluxing renal transplant ureteroneocystostomies in children

The Extended Utilization of Bulking Agents in Pediatric Urology

PURPOSE OF REVIEW

Traditional surgical management for urinary incontinence and vesicoureteral reflux often requires complex reconstructive surgery and extended hospitalizations. Since the introduction of endoscopic bulking agents in 1973, there has been increasing interest in the use of endoscopic injection (EI) and bulking for the treatment of a variety of pediatric urologic disorders. The purpose of this review is to summarize the most recent literature addressing the use of bulking agents in pediatric urology.

RECENT FINDINGS

The most recent literature has focused primarily on the use of EI of bulking agents at the bladder neck for the treatment of urinary incontinence. Other uses of EI of bulking agents has focused on the treatment of vesicoureteral reflux (VUR) in patients with anatomic abnormalities or treatment of incontinence catheterizable channels. The development of advanced techniques for endoscopic injection along with safe, stable bulking agents has allowed for the treatment of a variety of urologic conditions. This minimally invasive procedure offers an additional tool for the pediatric urologist's armamentarium in the treatment of urinary incontinence and VUR.

Revision ureteroneocystostomy in pediatric renal transplant patients for symptomatic vesicoureteral reflux and its effect on recurrent hospitalizations

BACKGROUND

Nearly 13,000 pediatric renal transplantations have been performed since 1987 with improving overall mortality and morbidity; however, graft infection remains a significant post-transplant concern. Recurrent urinary tract infections in pediatric patients with vesicoureteral reflux into their renal transplant can result in graft dysfunction, increased hospital cost, and impaired social and cognitive development due to time spent hospitalized.

OBJECTIVE

To evaluate the effect of revision ureteroneocystostomy on pediatric renal transplant patients with symptomatic vesicoureteral reflux in reducing hospitalizations and recurrent urinary tract infections.

METHODS

We retrospectively reviewed pediatric patients from 2002 through 2021 who underwent renal transplantation and required revision ureteroneocystostomy due to symptomatic vesicoureteral reflux. We analyzed the differences in days hospitalized, days hospitalized due to urinary tract infection, and treated urinary tract infections prior to and after revision ureteroneocystostomy.

RESULTS

Ten patients requiring revision ureteroneocystostomy secondary to symptomatic vesicoureteral reflux were identified. There was no difference in the observation time between transplant to revision, and revision to last follow up (2.3 years (IQR 1.3-6.5) vs 1.7 years (IQR 1-6.7), p = 0.4446). Overall, there was a significant decrease in the total number of hospitalization days (21.5 days (IQR 3-43) vs 5.5 days (IQR 0-9), p = 0.006), total number of hospitalization days related to urinary tract infection (14.5 days (IQR 3-28) vs 0 days (IQR 0-3), p = 0.008) and treated urinary tract infections (3.5 (IQR 3-6) vs 1 (IQR 0-2), p = 0.019) following revision ureteroneocystostomy. The rate of hospitalization days for urinary tract infection was also significantly decreased following revision ureteroneocystostomy (7.15 per/year (IQR 0.4-11.75) vs 0 per/year (IQR 0-0.8), p = 0.008).

DISCUSSION

Symptomatic vesicoureteral reflux in pediatric transplant patients is difficult to manage and some patients will ultimately require surgery. There have been previous studies on the success of revision ureteroneocystostomy in treating reflux but no data on the reduction in hospitalizations associated with recurrent infections following the procedure. Limitations of this study are the small cohort size, retrospective nature, multi-surgeon study, and inherent selection bias due to evaluation of only surgical patients.

CONCLUSION

Revision ureteroneocystostomy can limit the negative consequences of recurrent graft infections with reduction in hospitalization days and improved hospitalization rates due to urinary tract infections. The reduction in hospitalizations can greatly improve the cost of care along with quality of life for transplant patients and should be strongly considered in children with symptomatic vesicoureteral reflux who have failed conservative therapy.

A systematic review of outcomes of Deflux® treatment for vesicoureteral reflux following pediatric renal transplantation

INTRODUCTION

Vesicoureteral reflux (VUR) after renal transplant in the pediatric population may be associated with an increased incidence of urinary tract infection (UTIs) leading to increased morbidity, including graft dysfunction and graft loss. The non-orthotopic location of the transplanted ureter, and lack of submucosal tunnel may pose challenges in correcting the VUR using endoscopic injection techniques. Herein we report the results of a systematic review evaluating the outcomes of endoscopic treatment of VUR using Deflux® in this population.

METHODS

Pubmed and Embase databases were searched from October 2001 to April 2019. Full-text English articles involving patients less than 18 years old at the time of transplant, with a diagnosis of VUR post-transplantation, who underwent Deflux® treatment were included. Figure 1 outlines our PRISMA-compliant search strategy.

RESULTS

We found 6 eligible studies describing Deflux® treatment outcomes in 67 pediatric patients with post-transplant VUR where voiding cystourethrogram (VCUG) confirmed the diagnosis and resolution of VUR. The mean success rate was 36.8%. Ureteral obstruction occurred in 7/67 cases (10.4%). In all these 7 cases of obstruction, ureteric stenting was the initial management, but was only successful in 1 patient. Open ureteroneocystostomy (UNC) was performed in 4/7 cases, while 2/7 were managed expectantly (unknown outcomes). Persistent VUR with UTI despite Deflux® were reported in 20 out of 67 cases. Of these, 7 were managed with prophylactic antibiotics, and 13 with UNC. Success rates were consistently low for UNC after failed Deflux® in comparison to redo UNC in transplant ureters without prior injection.

CONCLUSION

Low success rates are seen following injection techniques for VUR after pediatric renal transplant. Although an appealing option, Deflux® may prove counterintuitive due to the high rate of obstruction and suboptimal results if open reimplantation is required. A multi-institutional prospective study with a larger population size may further elucidate these results.

Treatment of Vesicoureteral Reflux Detected After Renal Transplant in Pediatric Patients: A Single-Center Experience

OBJECTIVE

In children who undergo renal transplant, vesicoureteral reflux on the transplanted kidney is a serious complication that may result in organ loss. In this study, we aimed to evaluate the results of endoscopic and open surgical techniques in the treatment of patients with recurrent urinary tract infections and vesicoureteral reflux after renal transplant.

MATERIAL AND METHODS

The files of pediatric patients who underwent renal transplant in our hospital between January 2016 and January 2019 were evaluated retrospectively. In this single-center analysis, we investigated the incidence of vesicoureteral reflux in the kidney transplant recipients and the results of various approaches to treat it.

RESULTS

Eighty pediatric patients underwent renal transplant between January 2016 and January 2019. Fourteen of those patients (17.5%, 7 female and 7 male) were diagnosed with vesicoureteral reflux in the postoperative period. Twelve of 14 patients received endoscopic injections as the first treatment. Clinical or radiological success was achieved in 5 patients (5 of 15 injection treatments, 33%); in 4 patients (4/12, 33.3%) success was after the first endoscopic injection treatment, and in 1 patient (1/3, 33.3%) success was after the second injection. Meanwhile, clinical or radiological success was achieved in 6 of 7 patients who underwent redo ureteroneocystostomy (6/7, 85.7%).

CONCLUSION

Although symptomatic vesicoureteral reflux after renal transplant is rare in pediatric patients, it is an important cause of morbidity as it requires recurrent surgical procedures. Although endoscopic treatment is safe and minimally invasive, the success rate is lower than expected, and redo of ureteral reimplant may be required in most cases.

When does vesicoureteral reflux in pediatric kidney transplant patients need treatment?

PURPOSE

The treatment of VUR in children with UTI has changed significantly, due to studies showing that antibiotic prophylaxis does not decrease renal scarring. As children with kidney transplants are at higher risk for UTI, we investigated if select patients with renal transplant VUR could be managed without surgery.

MATERIALS AND METHODS

A total of 18 patients with VUR into their renal grafts were identified, and 319 patients underwent transplantation from 2006 to 2016. The cause for the detection of the VUR, treatment, and graft function was reviewed.

RESULTS

Six boys and 12 girls were identified, 13 of whom had grade 3 or 4 VUR into the renal graft. Nine patients presented with hydronephrosis or abnormal renal biopsy: eight were successfully managed with antibiotic prophylaxis and bladder training, one developed UTI and underwent Dx/HA subureteric injection. Nine patients presented with recurrent febrile UTI, only one was successfully managed without surgery. Only 2 of 9 (22%) patients who underwent Dx/HA injection had resolution of their reflux. Of the remaining seven, five required open ureteral reimplantation (two for obstruction), one lost the graft due to rejection, and one had significant hydronephrosis. eGFR was similar between the hydronephrosis, UTI, and abnormal renal biopsy groups at all times.

CONCLUSION

Patients with transplant VUR and recurrent febrile UTI are more likely to require surgical therapy, but the complication and failure rate for Dx/HA injection is significant. Patients with transplant VUR without febrile UTI can be successfully managed with bladder training and temporary antibiotic prophylaxis.

Comparing treatment modalities for transplant kidney vesicoureteral reflux in the pediatric population

INTRODUCTION

Non-refluxing ureteral reimplantation is favored in pediatric renal transplantation to prevent complications, such as vesicoureteral reflux (VUR) in the transplant ureter. VUR resulting in febrile urinary tract infections remains a problem in this population, leading to repeated hospitalizations and increased morbidity. Revision of the vesicoureteral anastomosis can be a surgical challenge due to scar tissue and tenuous vascularity of the transplant ureter. Therefore, alternative options such as endoscopic injection of Deflux at the neo-orifice and surveillance with prophylactic antibiotics have emerged as potential treatment modalities for transplant ureter VUR.

OBJECTIVE

The authors reviewed their experience of the management of VUR in the transplant ureter, comparing outcomes of various modalities.

STUDY DESIGN

With Institutional Review Board approval, a retrospective chart review of all renal transplant patients from January 2002 to January 2017 was conducted. All patients with VUR on voiding cystourethrogram (VCUG) after surgery were identified. Indications for end-stage renal disease, urologic comorbidities, pretransplant VCUG, and operative details were recorded. After transplantation, febrile urinary tract infections, ultrasound findings, and any further interventions-surveillance, subureteral endoscopic injection of Deflux, or ureteral reimplantation-were documented along with their outcomes.

RESULTS

Overall, VUR was identified in 35/285 (12.3%) transplant patients after a non-refluxing ureteroneocystostomy. VUR was managed with surveillance in 17/35 (49%), intravesical Deflux injection in 11/35 (31%), and immediate redo ureteral reimplantation in 7/35 (20%). Ten out of 11 patients undergoing Deflux injection had a postoperative VCUG. All patients developed VUR recurrence; the majority showed immediate failure and only 1/10 showed late recurrence. Of the immediate failures, 3/9 patients were maintained on prophylactic antibiotics, and 6/9 patients underwent ureteral reimplantation. In these six patients undergoing reimplantation after failed Deflux, 3/6 (50%) patients required additional surgeries: One patient developed recurrence of reflux and two patients developed ureterovesical junction obstruction. In contrast, no complications were seen in patients undergoing primary ureteral reimplantation.

DISCUSSION

The study is limited by low numbers and a retrospective design. However, the results of this study differ significantly from the published Deflux series showing a success rate of more than 50% in the treatment of transplant kidney VUR. In fact, post-Deflux redo ureteral reimplantation was associated with an increased risk of postoperative complication.

CONCLUSION

The use of Deflux in the post-transplant setting has poor results. In the study series, 11/11 patients demonstrated clinical and radiographic failure. Therefore, as an institution the authors do not recommend Deflux as first-line treatment of VUR in the transplant patient.

Endoscopic antireflux surgery leading to obstruction in pediatric renal transplant patients

To describe a multicenter experience with management of ureteral obstruction after injection of Dx/HA for VUR in pediatric renal transplant patients. The records of all pediatric renal transplant patients who underwent Dx/HA injection for VUR and had subsequent obstruction were identified, and the management and outcomes were reviewed. Follow-up ranged from 1 to 10 years. There were four patients identified, all of whom had a history of rising creatinine, recurrent UTI, and increasing hydronephrosis which led to the diagnosis of high-grade VUR. Obstruction was diagnosed within 24-72 hours after injection in three patients. One patient was asymptomatic, and rising creatinine and hydronephrosis were noted 1 month after injection. One patient was managed expectantly, while three patients underwent ureteral stent placement. After the stent was removed, one patient went on to open reimplant due to delayed obstruction, the second patient with voiding dysfunction is currently managed with an indwelling ureteral stent and may require further definitive surgery, the third patient recovered, and the fourth is being observed. Our cases illustrate that despite initial successful management of the obstruction in some, delayed obstruction is possible and may necessitate open reimplant. It is imperative that these patients have close follow-up after Dx/HA.

National risk factors and estimated costs for redo ureteroneocystostomy after pediatric renal transplant

Approximately 800 pediatric renal transplants are performed annually in the United States. VUR or obstruction may cause graft failure requiring redo ureteroneocystostomy. We examined possible risk factors and cost using the PHIS national database. We examined the PHIS for 8.5 yr to determine the association between redo ureteroneocystostomy following pediatric renal transplant to demographics, comorbidities, GU conditions, insurance status, and hospital characteristics, and looked at relative costs using descriptive and comparative statistics. A total of 2390 pediatric renal transplants were identified, of which 69 (2.3%) underwent redo ureteroneocystostomy (median 11.6 months post-transplant). Risk factors for redo ureteroneocystostomy are younger age (p = 0.048), PUVs (p < 0.001), female gender (p = 0.005), race (p = 0.014), insurance type (p < 0.027), region (p = 0.045), and transplant surgery volume (p = 0.048). Redo ureteroneocystostomy after transplant does not significantly increase the overall cost of transplant (p = 0.175). We confirmed previous findings that younger age and PUVs increase the risk of post-transplant redo ureteroneocystostomy, with a five-yr plateau. We found an association with gender, race, insurance status, and hospital characteristics. Redo ureteroneocystostomy, which increases costs, does not statistically significantly increase overall cost of individual treatment in this database, although costs may be underreported.

Ureteral complications after renal transplant in children: timing of presentation, and their open and endoscopic management

We retrospectively reviewed the records of 24 consecutive patients undergoing treatment for ureteral complications after RTx in the period 2001-2012 to determine the timing of presentation of the complications, and their open or endoscopic management. Three patients (12%) had a necrosis of the transplanted ureter soon after RTx. All required open urinary diversion in a native ureter. Ten cases (42%) developed ureteral obstruction. Time of presentation was variable mainly in relation to the underlying cause. Endoscopic treatment was successful in two cases with urinary stones and open surgery in two with mid-ureteral obstruction. Six patients had VUJ stenosis, three underwent open reimplantation, whereas temporary double-J stent placement was successfully performed in the remainder. Eleven patients (46%) had VUR. It seldom presented in the first year after RTx. Endoscopic treatment was attempted in all and was successful in all the six cases without vs. only one of the five with lower urinary tract pathology (p = 0.01). Endoscopic treatment is an option in patients with VUR in the absence of lower urinary tract pathology. It is an option also for the treatment of stones and can be attempted in case of VUJ stenosis. Ureteral necrosis always requires open treatment.

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.

Endoscopic vesicoureteral reflux correction in transplanted kidneys: does injection technique matter?

AIM AND BACKGROUND

Posttransplant vesicoureteral reflux (VUR) is a common urologic complication after renal transplantation, although its management is controversial. The treatment of choice is open surgical revision ureteral reimplantation with significant morbidity. Recently, endoscopic correction by using nonanimal dextranomer/hyaluronic acid copolymer (NA Dx/HA) injection has been reported to be effective in the treatment of VUR of transplanted kidneys. Herein, we present our 3-year endoscopic correction results in transplanted kidneys where we used two different injection techniques, subureteral and intraureteral.

MATERIALS AND METHODS

We retrospectively reviewed all patients who underwent endoscopic VUR correction of posttransplant VUR by NA Dx/HA injection between July 2005 and March 2009. We excluded patients with underlying urologic abnormalities.

RESULTS

A total of 26 patients (14 women and 12 men) with a mean age of 32.2 years (range: 15–55) were studied. The VUR was also graded as nondilating reflux in 10 (grade I–II) and dilating reflux in 16 (grade III–IV). Seventeen ureters (5 nondilating and 12 dilating VUR) were injected NA Dx/HA intraureterally, and 9 ureters (5 nondilating and 4 dilating VUR) were injected NA Dx/HA subureterally. Overall success rate was 53.8% (14 out of 26). Intraureteral injection technique was successful in nine cases (52.9%), and subureteral injection technique was successful in five cases (55.5%). In nondilating VUR, injection corrected 90% (9 out of 10) of posttransplant patients, whereas in dilating VUR group injection corrected only 31.25% (5 out of 16). We found no statistical significance of injection technique on the success rate.

CONCLUSIONS

Endoscopic correction by using NA Dx/HA with any injection technique seems to be a plausible alternative to correction of refluxing posttransplant ureters, particularly in nondilating VUR.