The outcomes of two different bulking agents (dextranomer hyaluronic acid copolymer and polyacrylate-polyalcohol copolymer) in the treatment of primary vesico-ureteral reflux

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.

Surgical management of vesicoureteral reflux in adults

Vesicoureteral reflux (VUR) is the retrograde flow of urine from the bladder into the upper urinary tract with or without upper-tract dilatation. This diagnosis is commonly made in childhood, affecting 1% of all births. In adults, its prevalence and incidence are not known. Presentation in adults could be with loin pain associated with voiding or a full bladder, recurrent urinary tract infections, a diagnosis carried over from childhood or an incidental finding. Most of the works on VUR have been done in the paediatric population. There are limited publications addressing VUR in adults. Unsurprisingly, the management of VUR in adults is extrapolated from the knowledge that we have gained from paediatric urology. Herein, we recap on the pathophysiology and review the surgical management of VUR in adults as published over the years.

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.

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.

Changing bulking agent may require change in injection volume for endoscopic treatment of vesicoureteral reflux

Introduction:

Various bulking agents were utilized for endoscopic correction of VUR. A study reviewing multi-institutional data showed that the amount of injection material has increased over time with the purpose of improving success rates, which also resulted in costs. We noticed an opposite trend in our center since we started using a new bulking agent. The aim of this study was to evaluate evolution of our practice with different bulking agents.

Patients and Methods:

Records of VUR patients who underwent subureteric injection with polyacrylate polyalcohol copolymer (PPC) and dextronomere hyaluronic acide (DxHA) between 2005 and 2014 were reviewed. Variation of different parameters throughout the study period was evaluated along with the success rate. Success was defined as complete resolution of reflux.

Results:

A total of 260 patients with 384 refluxing units were included. The success rate was higher in PPC group compared to DxHA group. There was no statistically significant difference between years regarding distribution of VUR grade, body weight, patient height, and age in PPC group. Despite significant reduction in injection volume, success rate did not decrease through the years with PPC.

Conclusion:

Different bulking agents may require different injection volumes to achieve the same success rate in endoscopic treatment of vesicoureteral reflux. Habits gained with previous experience using other materials should be revised while using a new agent.

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.