Endoscopic treatment of grades IV and V vesicoureteral reflux with two bulking substances: Dextranomer hyaluronic acid copolymer versus polyacrylate polyalcohol copolymer in children

Vantris vs. deflux for treatment of paediatric vesicoureteral reflux: Efficacy and obstruction risk

INTRODUCTION

The aim was to compare the efficacy of polyacrylate polyalcohol copolymer (PPC) injections and dextranomer/hyaluronic acid (Dx/Ha) injections for the endoscopic treatment of vesicoureteral reflux in children.

MATERIAL

This retrospective cohort study included 189 young patients who had endoscopic treatment for vesicoureteral reflux from January 2012 to December 2019 in our center. Among them, 101 had PCC injections and 88 had Dx/Ha injections. Indications for treatment were vesicoureteral reflux with breakthrough urinary tract infection or vesicoureteral reflux with renal scarring on dimercaptosuccinic acid (DMSA) renal scan. Endoscopic injection was performed under the ureteral meatus. Early complications, recurrence of febrile urinary tract infection and vesicoureteral reflux after endoscopic injection, ureteral obstruction and reintervention were evaluated and compared between groups.

RESULTS

Endoscopic treatment was successful in 90.1% of patients who had PPC injection and in 82% of patients who had Dx/Ha injection. Four patients presented a chronic ureteral obstruction after PPC injection, one with a complete loss of function of the dilated kidney. One patient in the Dx/Ha group presented a postoperative ureteral dilatation after 2 injections.

CONCLUSION

Despite a similar success rate after PPC and Dx/Ha injections for endoscopic treatment of VUR, there may be a greater risk of postoperative ureteral obstruction after PPC injections. The benefit of using PPC to prevent febrile UTI and renal scarring in children with low-grade VUR does not seem to outweigh the risk of chronic ureteral obstruction.

LEVEL OF EVIDENCE: 4

Endoscopic injection of bulking agents in pediatric vesicoureteral reflux: a narrative review of the literature

In the last 20 years, endoscopic injection (EI) has affirmed as a valid alternative to open surgery for management of pediatric vesicoureteral reflux (VUR). This study aimed to investigate and discuss some debated aspects such as indications, bulking agents and comparison, techniques of injection and comparison, predictive factors of success, use in specific situations. EI is minimally invasive, well accepted by patients and families, with short learning curve and low-morbidity profile. It provides reflux resolution rates approaching those of open reimplantation, ranging from 69 to 100%. Obviously, the success rate may be influenced by several factors. Recently, it is adopted as first-line therapy also in high grade reflux or complex anatomy such as duplex, bladder diverticula, ectopic ureters. The two most used materials for injection are Deflux and Vantris. The first is absorbable, easier to inject, has lower risk of obstruction, but can lose efficacy over time. The second is non-absorbable, more difficult to inject, has higher risk of obstruction, but it is potentially more durable. The two main techniques are STING and HIT. To date, the ideal material and technique of injection has not yet clearly established, but the choice remains dependent on surgeon's preference and experience.

A systematic review & meta-analysis comparing outcomes of endoscopic treatment of primary vesico ureteric reflux in children with polyacrylate poly alcohol copolymer versus dextranomer hyaluranic acid

BACKGROUND & AIMS

There are conflicting reports on the efficacy of bulking agents for vesico ureteric reflux (VUR). In this meta-analysis we have compared the outcomes of endoscopic treatment with polyacrylate polyalcohol copolymer (PPC) and dextranomer hyaluronic acid (DxHA).

METHODS

A systematic review of publications between 2010 and 2020 was conducted covering databases like PUBMED, MEDLINE etc. for (endoscopic treatment) AND (VUR) AND (PPC OR DxHA) AND (recurrence OR complications). PRISMA guidelines were followed and only comparative studies were included. Outcomes were early success defined as absence of VUR in voiding cystourethrogram at 3-months followup, urinary tract infections (UTI) and occurrence of vesico-ureteric-junction obstruction (VUJO). Risk of bias was analysed with Robvis tool and odds-ratios were compared with Revman-3.0.

RESULTS

Among nine studies (heterogeneity; I 2 69-79%) all cleared the risk of bias assessment. There was no significant difference in high grade VUR (p = 0.94) between PPC (40%) and DxHA (43%). Success rate after single injection was significantly higher (p = 0.0001) at 86% (477/555) for PPC vs 69% (474/685) for DxHA. UTI rate between PPC (12%) and DxHA (14.6%) was not statistically significant (p = 0.54). VUJO rate between PPC (3.9%) and DxHA (0.8%) was also not significantly different (p = 0.47). Significantly lesser volume (p = 0.02) was used for PPC (0.7 ml) compared to DxHA (0.9 ml).

CONCLUSION

Reflux resolution was significantly higher with PPC than DxHA. Postinjection UTI/VUJO incidence was not significantly different between them. Limitation of this meta-analysis was heterogeneity & small number of articles. Further studies should focus on long-term outcomes and cost-effectiveness.

Comparison of polyacrylate polyalcohol copolymer (PPC) and dextranomer/hyaluronic acid (Dx/HA) for treatment of vesicoureteral reflux. A systematic review and meta-analysis

PURPOSE

Our study aimed to compare the efficacy of polyacrylate polyalcohol copolymer and Dextranomer-Hyaluronic Acid for endoscopic treatment of vesicoureteral reflux.

MATERIAL AND METHODS

MEDLINE, EMBASE, Scopus, Web of science, Ovid, Cochrane databases, Google scholar have been searched for studies published until January 2022 in any language. Studies that compared the success rate for endoscopic treatment of vesicoureteral reflux in children with two bulking agents, namely, "polyacrylate polyalcohol copolymer." and "Dextranomer-Hyaluronic Acid" were included for this analysis.

RESULTS

Nine studies were included in data synthesis for this meta-analysis. Pooled data with a total of 763 ureters in PPC group and 718 ureters in Dx/HA group indicated that ureters in PPC group were more likely to undergo complete reflux resolution than Dx/HA (OR 3.80, 95% CI: 2.71; 5.31). Among subgroup of patients with high grade reflux, PPC injection had more resolution rate compared to Dx/HA patients (OR: 2.92, 95% CI: 1.19-7.16). In total, 95.81% of the PPC group and 86.52% of the Dx/HA group experienced success after the third injection. However a concerning complication of endoscopic treatment which is ureterovesical junction obstruction (UVJO) was more prevalent in PPC group. So the possible benefits arising from endoscopic treatment with PPC could be offset by the costs of re-implantation surgery or stenting in the case of UVJO.

CONCLUSION

These data indicate that PPC injection for vesicoureteral reflux treatment was associated with a higher success rate, but concerningly, UVJO incidence was higher in the PPC group which might negate the possible benefits of PPC injection However, due to the lack of studies with long-term follow-up, we couldn't reach a definitive conclusion about the superiority of one of the bulking agents over the other.

Effectiveness and risks of endoscopic management compared to vesicoureteral reimplantation in patients with high-grade vesicoureteral reflux: systematic review and network meta-analysis

The purpose of this study is to determine the effectiveness and safety of endoscopic management compared to ureterovesical reimplantation in pediatric patients with high-grade vesicoureteral reflux in terms of urinary tract infection. We performed a network meta-analysis. We searched in MEDLINE, EMBASE, LILACS, and CENTRAL. We included clinical experiments, quasi-experiments, and cohorts studies. The population was men and women between 1 month and 15 years old. Patients had primary high-grade VUR diagnosed by voiding cystourethrography. The interventions were subureteric bulking agent endoscopic injection (polytetrafluoroethylene, hyaluronic acid, collagen, Dx/Ha, and PPC) vs vesicoureteral reimplantation (Cohen, Politano-Leadbetter, Glenn-Anderson, and Lich-Gregoir), and the primary outcome was urinary infections. Nine studies accomplished the inclusion criteria (seven observational and two clinical experiments). A total of 1448 renal units underwent surgical treatments for the correction of high-grade VUR. Regarding the primary outcome, we compared Dx/Ha with Cohen, Lich-Gregoir, and PPC, finding an RD of -0.02 (95%CI -0.09 to 0.06), RD of -0.02 (95%CI -0.10 to 0.07), and an RD of -0.03 (- 0.13 to 0.07), respectively.Conclusion: Our study showed that there were no differences in UTI episodes after VUR correction in patients undergoing endoscopic management compared with vesicoureteral reimplantation. What is Known: • Primary vesicoureteral reflux is one of the most common congenital anomalies of the urinary tract. • The clinical practice guidelines recommend the surgical management of patients with high-grade VUR. What is New: • There were no differences in UTI episodes after VUR correction in patients undergoing endoscopic management compared with vesicoureteral reimplantation.

Endoscopic Injection Treatment of Vesicoureteral Reflux in Children: Meeting with the Factors Involved in the Success Rate

The challenges and controversies in vesicoureteral reflux intervention guidelines resulted in a more individualized treatment planning. Endoscopic injection therapy is now widely used and is considered preferable, but still remains less successful than ureteral reimplantation. Τhe endoscopic vesicoureteral reflux approach should be risk-adapted to current knowledge, so more experience and longer-term follow-up are needed. The precise of preoperative, intraoperative, and postoperative factors that affecting endoscopic injection therapy success rates and outcome have not yet been clearly determined. The aim of this study was to investigate these associated factors. Although the reflux grade is the most well-known factor that can affect the success of the procedure, there is no agreement on which factors are the most influential for the efficacy of endoscopic reflux treatment. So, we carried out a broad review of published papers on this topic, and we presented all the potential predictive variables of endoscopic reflux resolution in children.

Proprietary non-animal stabilized hyaluronic acid/dextranomer gel (NASHA/Dx) for endoscopic treatment of grade IV vesicoureteral reflux: Long-term observational study

BACKGROUND

Since 1993, children aged >1 year with persistent grade III-V vesicoureteral reflux (VUR) and febrile urinary tract infections (UTIs) attending Uppsala University Hospital have undergone endoscopic injection with proprietary non-animal stabilized hyaluronic acid/dextranomer gel (NASHA/Dx; Deflux®).

OBJECTIVE

Investigate long-term incidence of UTI, bladder dysfunction, ureteral reimplantation and overall clinical findings following endoscopic injection of NASHA/Dx.

STUDY DESIGN

Children with grade IV VUR diagnosed by voiding cystourethrogram (VCUG) and dilating VUR persisting for >1 year were included in this study. 15-25 years after endoscopic treatment, patients' hospital charts were studied. Information on bladder function and UTIs was obtained via questionnaire, 8-18 years after endoscopic treatment.

RESULTS

185 patients (69 boys, 116 girls) were included in the study; 237 grade IV VUR ureters were treated. All study patients were diagnosed with VUR after a febrile UTI (i.e. pyelonephritis). According to the last voiding cystourethrogram, 69% of ureters showed a positive response (VUR grade 0-I), 7% had VUR grade II and 23% had VUR grade ≥ III. 46 patients (25%) required ureteral reimplantation during follow-up. Among patients treated during the second 5-year period compared with the first (1998-2003 versus 1993-1998), there was a significant decrease in the rate of ureteral reimplantation (31% vs 16%; p = 0.0365). This difference may be attributable to developments over time in the injection technique. UTIs occurred in 30 patients (21% of the evaluable population): 28 females and 2 males. Febrile UTIs were reported in 14 patients (10%), all females. Forty-nine patients (34%) had bladder problems (e.g. underactivity, overactivity, incontinence). Five patients underwent ureteral reimplantation 'late', 6-10 years after the last endoscopic injection. In one male patient, calcification around the NASHA/Dx implantation site was observed during routine examination 2 years after endoscopic treatment; no intervention was required. No safety issues were observed in the remaining 97% of the study population.

CONCLUSIONS

This study represents the longest published follow-up of Grade IV VUR patients undergoing endoscopic treatment. Three-quarters of patients did not need ureteral reimplantation. Optimal injection technique and higher injection volume were associated with a reduced ureteral reimplantation rate. Treatment with NASHA/Dx was durable and well tolerated: long-term risks of UTI, bladder dysfunction and recurrent VUR were low.

Risk factors for obstructive complications after endoscopic correction of vesico-ureteral reflux using polyacrylate polyalcohol copolymer

Use of polyacrylate-polyalcohol copolymer (PPC) after endoscopic correction (EC) of vesico-ureteral reflux (VUR) is highly effective but is associated with a higher risk of obstructive complications (OC) compared with other implants. We undertook a STROBE compliant retrospective investigation and studied the OC risk factors to increase the practical safety of PPC.Overall, 798 patients (464 [58.1%] girls and 334 [41.9%]) boys) from 5 hospitals in whom PPC was routinely used were evaluated retrospectively. The patients were subdivided into 2 groups. Group I consisted of 754 (94.5%) children (449 [59.5%] girls and 305 [40.5%] boys) without OC. Median age was 41 months [Q1: 18.0; Q3: 81.0]. Group II comprised 44 (5.5%) patients (29 [65.9%] boys and 15 [34.1%] girls) experiencing OC, and their median age was 21.5 months [Q1: 12.0; Q3: 43.0]. Clinical and renal ultrasound examinations were carried out 1 day and 1 month after EC, and then every 6 months after EC. At the follow-up examination approximately 6 months after EC, voiding cysto-urethrography (VCUG) was performed. All patients with OC underwent diuretic renography.OC occurred in 44 (5.5%) of 798 children, in some cases as late as 60 months after endoscopic injection of the bulking agent PPC for correction of VUR. Univariate analysis revealed that younger age (P < .001), higher grade of VUR (P < .001), male gender (P < .001), second injection (P = .003), and EC injection using hydrodistension implantation technique (HIT; P < .001) represented significant risk factors. At multivariate analysis, only male gender (P = .0078), younger age (P = .0044), HIT technique (P < .0001), and second injection (P = .04) represented significant risk factors for the occurrence of OC.We identified young age, male gender, high reflux grade, HIT technique, and second endoscopic injections as factors associated with the risk of OC after EC of VUR using PPC as a bulking agent. Thus, patients who have undergone EC with PPC must be monitored sonographically for occurrence of OC for at least 60 months after the intervention.

A review of novel STING bulking agents

OBJECTIVE

The objective of this study was to review the literature to compare the efficacy and complications of polyacrylate-polyalcohol copolymer (PPC) and polyacrylamide hydrogel (PAHG) with the current standard of care, dextranomer/hyaluronic acid (Dx/HA), when used to treat VUR in the paediatric population.

METHODS

PubMed, Embase and Cochrane databases were searched. Keywords included Vesicoureteral reflux (VUR), endoscopic; endoscopic injection, endoscopic treatment, dulking material, dextranomer/hyaluronic acid copolymer, polyacrylate-polyalcohol copolymer, Deflux, Dexell, Vantris, Bulkamid, outcome, treatment and children. Prospective or retrospective studies comparing PAHG/PPC directly with Dx/HA were included for review.

RESULTS

Four studies were identified comparing PPC with Dx/HA. All studies showed superior efficacy (on micturating cystourethrogram (MCUG) at 3 months) of PPC over Dx/HA. However, 1 study identified a significantly higher rate of vesicoureteric junction obstruction (VUJO) in the PPC group. One study was identified comparing PAHG with Dx/HA which showed similar efficacy on 3-month MCUG.

CONCLUSIONS

Current data suggest PPC confers a higher resolution rate of VUR and PAHG confers comparable resolution rates for VUR compared with Dx/HA in the paediatric population. However, the incidence of late-onset VUJO in one study is concerning, and high-quality randomised controlled trials with long-term follow-up are needed before making further recommendations.

Macroplastique and Botox are superior to Macroplastique alone in the management of neurogenic vesicoureteric reflux in spinal cord injury population with presumed healthy bladders

CONTEXT/OBJECTIVE

Vesico-ureteric reflux(VUR) is a known complication of neuropathic bladder in spinal cord injury(SCI) population. Bulking agents such as Macroplastique are new minimally-invasive treatment option for VUR with good results. The aim of this study is to assess the efficacy of Macroplastique alone or in combination with Botox(BTX-A), in managing VUR in SCI population with presumed healthy bladders and correlate the pre-and post-injection urodynamic findings with the outcome.

DESIGN

Retrospective comparative study.

PARTICIPANTS

SCI patients with VUR and presumed health bladders (normo-compliant, low filling pressures), treated with macroplastique alone or in combination with BTX-A, who had pre and post-intervention Video-urodynamics (VUDS) and followed up for at least 12 months.

INTERVENTIONS

Macroplastique and BTX-A injections, VUDS.

OUTCOME MEASURES

The primary end point was the overall treatment rate of VUR at 3 months and the secondary outcomes were the success rate (treated + improved) and the comparison of urodynamic parameters (pre-and post-injection).

RESULTS

We studied 34 intervention-naïve SCI patients. 19 had only Macroplastique (Group 1) and 15 had Macroplastique and BTX-A (Group 2). The overall treatment rate was 65.4% for group 1 and 88.9% for group 2 (P = 0.029). The overall success rate (treated + improved) was 80.8% and 94.4% respectively (P = 0.123). The comparison of follow up VUDS parameters showed a statistically significant rise in the detrusor pressure of group 1 (34.04cmH2O vs.19.2cmH2O, P = 0.008) and a drop in compliance (19.8mls/cmH2O vs.26.3mls/cmH2O, P = 0.018) as compared to baseline.

CONCLUSION

The combination of BTX-A and Macroplastique is more effective that Macroplastique alone in the management of secondary VUR in SCI patients with presumed healthy bladders.

The learning curve of sting method for endoscopic injection treatment of vesicoureteral reflux

Objective:

To identify how many endoscopic injection (EI) procedures, STING method, must be performed before reaching an ideal success rate when simulation training has not been received.

Materials and Methods:

The EI procedures performed by two pediatric urology fellows were investigated. The study excluded patients without primary VUR and those with previous EI or ureteroneocystostomy, lower urinary tract dysfunction, and/or duplicate ureters. The EIs used dextranomer hyaluronate and the STING method, as described by O’Donnell and Puri. Groups number was determined by multiple statistical trials. Statistically significance differences were achieved with one combination that had 35 EI procedures each and with 3 different combination of patients, having 12, 24, and 36 patients, respectively. Therefore, groups were established 12 patients. The first fellow performed 54 EIs, and the second performed 51. Therefore, each of the first fellow's three groups contained 18 EI procedures, and each of the second fellow's 17.

Results:

The study included 72 patients and 105 ureter units. When the data from both fellows were combined, each of the three groups contained 35 procedures. For the first fellow, the success rates in the first, second, and third groups were 38.3%, 66.6%, and 83.3% (p = 0.02), respectively, and for the second fellow, the success rates were 41.2%, 64.7%, and 82.3% (p = 0.045), respectively. The increased success rates for both fellows were very similar.

Conclusions:

An acceptable rate of success for EI may be reached after about 20 procedures and a high success rate after about 35-40 procedures.

New bulking agent for the treatment of vesicoureteral reflux: Polymethylmethacrylate/dextranomer

Purpose

The aim of this study was to report preliminary results of endoscopic treatment of vesicoureteral reflux in children with a single injection of a new bulking agent, cross-linked dextran and polymethylmethacrylate mixture.

Materials and Methods

We performed a single-center, single surgeon, prospective, off-label study using polymethylmethacrylate/dextranomer to treat vesicoureteral reflux. All patients underwent endoscopic injection, followed by renal ultrasound and voiding cystourethrogram at 3 months postoperatively to identify de novo or worsening hydronephrosis and vesicoureteral reflux correction (to Grade 0 or I).

Results

Eighteen patients underwent injection of polymethylmethacrylate/dextranomer at our institution between April 2013 and December 2013. Ten were males and eight were females, with a median age of 58 months (range, 6 months to 5 years). Vesicoureteral reflux was unilateral in three patients and bilateral in 15, for a total of 33 renal refluxing units. Vesicoureteral reflux was Grade I in one renal refluxing unit, Grade II in 12, Grade III in 16, and Grade IV in four. Mean injected volume was 0.86 mL. Reflux was corrected in 23 renal refluxing units (69.7%) according to the 3-month voiding cystourethrogram. Complications included urinary retention in one patient. Mild pyelectasis was noted in one patient at 3 months, which spontaneously resolved 3 months later.

Conclusions

Our short-term data show that polymethylmethacrylate/dextranomer injection can be used to treat vesicoureteral reflux with comparable efficacy to other substances currently used and a low rate of complications. Long-term follow-up is required to confirm the usefulness of this material in treating vesicoureteral reflux.

Endoscopic correction of vesicoureteral reflux in children using polyacrylate-polyalcohol copolymer (Vantris): 5-years of prospective follow-up

Introduction

The endoscopic correction of vesicoureteral reflux (VUR) in children is a currently well accepted therapy in many pediatric urology centers. Polyacrylate-polyalcohol copolymer (PPC), namely Vantris^®, is one of the tissue-augmenting substances used for endoscopic reflux therapy. The aim of this study was to evaluate the results with PPC in children.

Material and methods

From 2012 to 2016, 125 children (73 girls and 52 boys) aged 0.6–17.9 years (mean 4.9 ±3.58) were treated with PPC. VUR was unilateral in 64 and bilateral in 61 patients, comprising 197 renal refluxing units (RRUs) grades: II in 72, III in 50, IV in 33 and V in 42. Of these primary reflux was present in 132 RRUs and 65 were complex cases. Voiding cystourethrogram (VCUG) was done 3 months after procedure.

Results

Follow-up was completed in 89.6% of patients (112 children), and 89.8% of RRUs (177 out of 197). Reflux resolved in 86.4% of RRUs after single injection, in 99.4% after second and in 100% after the third. The only significant, but serious complication observed was late ureteral obstruction after PPC injection correcting high grade reflux, which required ureteral re-implantation. This complication was found in 9 out of 112 children (8%), and in 11 out of 177 RRUs (6.2%), 1.1 -2.9 years (mean 2 ±0.7) after the PPC injection. The longest follow-up reaches 4.5 years.

Conclusions

Our data show that the PPC injection is an effective procedure for treating all grades of VUR with high success rate. However, because of the possibility of late ureteral obstruction, which requires ureteroneocystostomy, long-term follow-up is mandatory.

Endoscopic injection therapy

Since the U.S. Food and Drug Administration approved dextranomer/hyaluronic acid copolymer (Deflux) for the treatment of vesicoureteral reflux, endoscopic injection therapy using Deflux has become a popular alternative to open surgery and continuous antibiotic prophylaxis. Endoscopic correction with Deflux is minimally invasive, well tolerated, and provides cure rates approaching those of open surgery (i.e., approximately 80% in several studies). However, in recent years a less stringent approach to evaluating urinary tract infections (UTIs) and concerns about long-term efficacy and complications associated with endoscopic injection have limited the use of this therapy. In addition, there is little evidence supporting the efficacy of endoscopic injection therapy in preventing UTIs and vesicoureteral reflux-related renal scarring. In this report, we reviewed the current literature regarding endoscopic injection therapy and provided an updated overview of this topic.

Application of the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement to publications on endoscopic treatment for vesicoureteral reflux

OBJECTIVE

Following an increasing number of submissions on endoscopic treatment of vesicoureteral reflux (VUR), the Journal of Pediatric Urology sought to establish a quality guideline that would enable reviewers to select the best papers for publication in the journal. The "Strengthening the Reporting of Observational Studies in Epidemiology" (STROBE) Statement, established in 2007, is a 22-item checklist designed to assist with clear reporting of observational studies. This checklist includes a description of methodological items and instructions on how to use them to transparently report observational studies. The aim of the present study was to apply the STROBE principle to observational studies about endoscopic management of VUR, and to establish a "check-list" to assist authors with good-quality submissions.

STUDY DESIGN

The 22 STROBE criteria were listed and applied to publications on endoscopic treatment by utilizing examples from the current literature, with additional suggestions about how future studies could build upon the information already published on the subject.

RESULTS

Based on this strategy, a checklist that is particular to endoscopic treatment studies was produced as a guideline for authors and reviewers.

DISCUSSION

Application of the STROBE statement principles, in combination with key VUR data, will allow better quality submissions and a higher chance of positive reviews and acceptance rates.

Vesicoureteral reflux: From prophylaxis to surgery

Vesicoureteral reflux (VUR) is one of the most common pathologies encountered in pediatric urology. Better understanding of the evolution of VUR and new endoscopic surgical techniques in the last decades have led to major changes in the management of this pathology. However, the treatment algorithm remains complex and is composed of a wide variety of options, from active surveillance to surgical treatment. Herein, we propose to review treatment options for VUR in order to help clinicians make the right treatment decision for the right patient.