Endoscopic bulking materials for the treatment of vesicoureteral reflux: a review of our 20 years of experience and review of the literature

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

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.

Bladder Dysfunction and Re-Absorbable Bulking Agent Affect Success Rate in Children Underwent Endoscopic Treatment for Vesicoureteral Reflux: A Long-Term Follow-Up Study

This paper is designed to evaluate the results (at long-term follow-up of) children affected by dilating VUR. Our attention was focused on how VUR grade, laterality, bladder dysfunction (BD), the double renal system, and the type of bulking substance may affect VUR resolution in the long-term period. The charts of 93 children with dilating VUR who underwent endoscopic treatment (ET) and with a minimum post-operative follow-up of 7 years were reviewed (mean follow-up time was 9.6 + 1.4). The majority of patients had severe and bilateral VUR. Polydimetilsiloxane or hyaluronic acid/dextranomer (PDS or Ha/Dx) were used as bulking agents. VUR persistence following endoscopic injection was independent with respect to grade, laterality, duplex renal system, and BD. However, the rate of VUR persistence was significantly higher in children with BD. Children treated with Ha/Dx had a higher rate of VUR persistence. This research demonstrated that ET of VUR is also effective at very long term follow up (and without the development of significant complications). We also showed that patients treated with absorbable bulking agents such as Ha/Dx may experience a higher recurrence rate at the long-term follow-up). We also confirm that the only preoperative condition affecting VUR recurrence was bladder dysfunction.

Non-Animal Stabilized Hyaluronic Acid/Dextranomer Gel (NASHA/Dx, Deflux) for Endoscopic Treatment of Vesicoureteral Reflux: What Have We Learned Over the Last 20 Years?

Non-animal stabilized hyaluronic acid/dextranomer gel (Deflux; NASHA/Dx) was developed as a treatment for vesicoureteral reflux (VUR) in the 1990s. To mark 20 years since the US approval of this agent, we reviewed its properties, best practice for application, and the available clinical safety and efficacy data. Long-term or randomized, controlled studies of treatment with NASHA/Dx have reported VUR resolution rates of 59%-100% with low rates of febrile urinary tract infection post-treatment (4%-25%), indicating long-term protection of the kidneys. An individualized approach VUR management is advocated, and NASHA/Dx is a viable option for many patients requiring intervention.

Brazilian consensus on vesicoureteral reflux-recommendations for clinical practice

Introduction

Vesicoureteral Reflux (VUR) is characterized by a retrograde flow of urine from the bladder into the ureters and kidneys. It is one of the most common urinary tract anomalies and the major cause of urinary tract infection (UTI) in the first years of life. If not properly diagnosed and treated can lead to recurrent UTI, renal scar and, in severe cases, to end stage renal disease. Despite recent advances in scientific and technological knowledge, evaluation and treatment of VUR is still controversial and there is still considerable heterogeneity in evaluation methods and therapeutic approaches. The aim of the present consensus is to give a practical orientation on how to evaluate and treat VUR.

Methods

The board of Pediatric Urology of the Brazilian Society of Urology joined a group of experts and reviewed all important issues on Vesicoureteral Reflux evaluation and treatment and elaborated a draft of the document. On November 2017 the panel met to review, discuss and write a consensus document.

Results and Discussion

Vesicoureteral Reflux is a common and challenging problem in children. Children presenting with Vesicoureteral Reflux require careful evaluation and treatment to avoid future urinary tract infections and kidney scars. The panel addressed recommendations on up to date choice of diagnosis evaluation and therapies.

High-grade vesicoureteral reflux in infants: Our experience with endoscopic subureteric injections

BACKGROUND

Vesicoureteral reflux (VUR) is the most common urological anomaly in pediatric patients. Management options for VUR vary from continuous antibiotic prophylaxis (CAP) to surgery via either endoscopic subureteric injection of a bulking agent or open anti-reflux surgery. In this study, we assess the efficacy of subureteric injections of Dextranomer/Hyaluronic acid Copolymer (Deflux) in managing primary VUR in infant patients with high-grade VUR.

METHODS

From 2010 to 2015, children less than 1-year-old with primary high-grade VUR were observed prospectively following the administration of endoscopic subureteric injections of Dextranomer/Hyaluronic Acid Copolymer (Deflux). The diagnosis of VUR was based on MCUG, and all patients underwent a holistic clinical, laboratory, and radiological assessment before and after the intervention. Complete success was defined as the resolution of VUR on follow up 1 year post-operatively.

RESULTS

A total of 30 infants (50 renal units) with high-grade VUR (grades IV and V) were included in the study. The mean age at surgery was 6.3 ± 2.5 months. Most of the patients presented with a urinary tract infection (90%). Complete symptomatic relief was achieved in 27 patients (90%) at the first post-operative follow-up. Forty-four renal units received one injection, while six required a second injection as they did not meet our treatment success criteria. No patients required a third injection or referral for open surgery.

CONCLUSION

Endoscopic injection of Dextranomer/Hyaluronic acid Copolymer (Deflux) at the vesicoureteral junction is an effective minimally invasive intervention to treat high grades VUR (IV-V) infants.

The promise of regenerative medicine in the treatment of urogenital disorders

Polymers and scaffolds are the most significant tools in regenerative medicine. Urogenital disorders are an important group of diseases that greatly affect the patient's life expectancy and quality. Reconstruction of urogenital defects is one of the current challenges in regenerative medicine. Regenerative medicine, as well as tissue engineering, may offer suitable approaches, while the tools needed are appropriate materials and cells. Autologous urothelial cells obtained from biopsy, bone marrow-derived stem cells, adipose stem cells and urine-derived stem cells that expressed mesenchymal cell markers are the cells that mainly used. In addition, two main types of biomaterials mainly exist; synthetic polymers and composite scaffolds that are biodegradable polymers with controllable properties and naturally derived biomaterials such as extracellular matrix components and acellular tissue matrices. In this review, we present and evaluate the most appropriate and suitable scaffolds (naturally derived and synthetic polymers) and cells applied in urogenital reconstruction.

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.

Long-term Outcomes of Endoscopic Anti-reflux Surgery in Pediatric Patients with Vesicoureteral Reflux: Urinary Tract Infection, Renal Scarring, and Predictive Factors for Success

BACKGROUND

To report the long-term outcomes of endoscopic surgery (ES) in pediatric patients with vesicoureteral reflux in terms of success rate, urinary tract infection, and renal function.

METHODS

We retrospectively reviewed the records of 73 pediatric patients (110 ureters) who underwent ES for vesicoureteral reflux. Ultrasonography was performed 1, 3, and 12 months postoperatively. Voiding cystourethrography was performed 3 months postoperatively and repeated after 1 year if vesicoureteral reflux persisted. Success was defined as the absence of reflux at the first voiding cystourethrography. Renal scans were performed at least 12 months postoperatively. Renal function deterioration was defined as a new scar or a greater than 5% decrease in function.

RESULTS

The median follow-up duration was 24 (12-118) months. The overall success was 65.6%, while it was 78.9%, 87.0%, 62.5%, 37.5%, 66.7% for grades I, II, III, IV, and V, respectively. In multivariate analyses, significant predictive factors for success were vesicoureteral reflux grade (odds ratio [OR], 0.28; P < 0.001) and mound detection at the first postoperative ultrasonography (OR, 13.53; P < 0.001). Renal function deterioration was found in 8 (15.3%) ureters and was less common in those with successful surgeries than in those with failures (9.5% vs. 40.0%; P = 0.035). No significant predictive factor for renal function deterioration or urinary tract infection was found.

CONCLUSION

Successful short-term outcomes of ES are expected in low-grade vesicoureteral reflux, especially when a mound is detected by postoperative ultrasonography. However, unpredictable long-term renal deterioration warrants continued follow-up.

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.

Incidence of ureterovesical obstruction and Cohen antireflux surgery after Deflux® treatment for vesicoureteric reflux

AIM

The purpose of this study was to determine the incidence of ureteric obstruction (UB) and requirement for Cohen antireflux surgery (CAS) after Deflux^Ⓡ treatment (DT) for vesicoureteric reflux (VUR).

METHODS

Between 2011 and 2017, 494 ureters (VUR severity ≤ grade III: N=291 or >grade IV: N=203) were treated by DT at a mean age of 4.5 (range: 0.2-24) years. Epidural Catheter Assistance (ECA) was used to exclude UB by injecting diluted indigo carmine solution (1-3mL) into an epidural catheter inserted into a ureter after DT and confirming dye flow within 15min. ECA+: N=181 ureters; ECA-: N=313 ureters.

RESULTS

In ECA+, UB was detected in 5/181 (2.7%) ureters (grade II: N=1, III: N=3, and IV: N=1) treated by leaving the ECA catheter in situ overnight (N=4) or double J stent (DJS) insertion for 1month (N=2). After mean follow-up of 1.9years, one grade III DJS case has residual grade II VUR. In ECA-, 3/313 (0.9%) cases developed UB. One resolved, and one required DJS. CAS was required for 17/494 (3.4%) ureters and hindered by DT in 5/17 (29.4%) ureters. All are sequelae-free after mean follow-up of 1.8years.

CONCLUSIONS

UB may be more frequent than reported (3.3% versus 0.6%-1.8%). ECA identifies potential UB.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level III.

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.

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.

Polyacrylamide Hydrogel as a Bulking Agent for the Endoscopic Treatment of Vesicoureteral Reflux: Long-Term Results and Safety

PURPOSE

Polyacrylamide hydrogel has been shown to offer good short-term success for the endoscopic treatment of vesicoureteral reflux. Our objective was to provide long-term results of its efficacy and safety.

MATERIALS AND METHODS

We performed a prospective study using polyacrylamide hydrogel to treat all grades of vesicoureteral reflux. Every patient underwent endoscopic injection of polyacrylamide hydrogel followed by 3-month postoperative renal ultrasound and voiding cystourethrogram. Renal ultrasound was repeated at 12 and 36 months. Treatment success was defined as the absence of de novo or worsening hydronephrosis and the absence of reflux. Safety elements included new or worsening hydronephrosis, calcifications of the injected material and urinary tract infections.

RESULTS

A total of 76 patients (123 refluxing renal units) were assessed. Median age at surgery was 45 months and median followup was 36 months. Median injected volume of hydrogel per refluxing renal unit was 1.0 ml. The overall success rate 3 months after a single injection was 71%. During long-term followup 68 of 70 eligible patients underwent 12-month ultrasound and 40 of 46 underwent 36-month ultrasound. No upper tract deterioration or bulking agent calcifications were reported. Nine (12%) and 2 patients (3%) presented with nonfebrile and febrile urinary tract infections, respectively.

CONCLUSIONS

The success rate of polyacrylamide hydrogel for endoscopic treatment of vesicoureteral reflux is comparable to published results of dextranomer hyaluronic acid. The long-term safety data and potential lower cost of polyacrylamide hydrogel provide further support for the use of this nonparticulate bulking agent to treat reflux.

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

PURPOSE

Subureteral injection of bulking agents in the endoscopic treatment of vesicoureteral reflux is widely accepted therapy with high success rates. Although the grade of vesicoureteric reflux and experience of surgeon is the mainstay of this success, the characteristics of augmenting substances may have an effect particularly in the long term. In this retrospective study, we aimed to evaluate the clinical outcomes of the endoscopic treatment of vesicoureteric reflux (VUR) with two different bulking agents: Dextranomer/hyaluronic acid copolymer (Dx/HA) and Polyacrylate polyalcohol copolymer (PPC).

MATERIALS AND METHODS

A total 80 patients (49 girls and 31 boys) aged 1-12 years (mean age 5.3 years) underwent endoscopic subureteral injection for correction of VUR last six years. The patients were assigned to two groups: subureteral injections of Dx/HA (45 patients and 57 ureters) and PPC (35 patients and 45 ureters). VUR was grade II in 27 ureters, grade III in 35, grade IV in 22 and grade V in 18 ureters.

RESULTS

VUR was resolved in 38 (66.6%) of 57 ureters and this equates to VUR correction in 33 (73.3%) of the 45 patients in Dx/HA group. In PPC group, overall success rate was 88.8% (of 40 in 45 ureters). Thus, Thus, this equates to VUR correction in 31 (88.5%) of the 35 patients.

CONCLUSIONS

Our short term data show that two different bulking agent injections provide a high level of reflux resolution and this study revealed that success rate of PPC was significantly higher than Dx/HA with less material.

Efficacy of dextranomer hyaluronic acid and polyacrylamide hydrogel in endoscopic treatment of vesicoureteral reflux: A comparative study

INTRODUCTION

Various bulking agents are available for vesicoureteral reflux (VUR) endoscopic treatment, but their inconsistent success rates and costs are concerns for urologists. Recently, polyacrylamide hydrogel (PAHG) has been shown to have a good overall success rate, which seems comparable to dextranomer hyaluronic acid (Dx/HA), currently the most popular bulking agent. Our objective was to compare the short-term success rate of PAHG and Dx/HA for VUR endoscopic treatment in children.

METHODS

We performed a prospective non-randomized study using PAHG and Dx/HA to treat VUR grades I to IV in pediatric patients. All patients underwent endoscopic sub-ureteric injection of PAHG or Dx/HA, using the double-HIT technique, followed by a 3-month postoperative renal ultrasound and voiding cystourethrogram. Treatment success was defined as the absence of de novo or worsening hydronephrosis and absence of VUR.

RESULTS

A total of 90 pediatric patients underwent an endoscopic injection: 45 patients (78 ureters) with PAHG and 45 patients (71 ureters) with Dx/HA. The mean injected volume of PAHG and Dx/HA was 1.1 mL and 1.0 mL, respectively. The overall success rate 3 months after a single treatment was 73.1% for PAHG and 77.5% for Dx/HA. Postoperatively, 1 patient in each group presented with acute pyelonephritis and 2 patients in the Dx/HA group developed symptomatic ureteral obstruction.

CONCLUSION

Success rates of PAGH and Dx/HA in endoscopic injections for VUR treatment were comparable. The rate of resolution obtained with Dx/HA was equivalent to those previously published. The lower cost of PAHG makes it an interesting option.

The Biocompatibility of a Cellulose Exopolysaccharide Implant in the Rabbit Bladder When Compared With Dextranomer Microspheres Plus Hyaluronic Acid

OBJECTIVE

To evaluate biocompatibility of a cellulosic exopolysaccharide (CEC) as bulking agent in rabbit urinary bladder.

MATERIALS AND METHODS

The experimental study was developed at the Nucleus for Experimental Surgery or UFPE. The new agent was injected into the bladder of the adult rabbits using a small abdominal incision. Animals were injected with 0.2 mL of dextranomer microspheres (Dx) plus hyaluronic acid and CEC. The animals were studied after 3 days (G1), 90 days (G2), and 11 months (G3). The biocompatibility was evaluated according to the histologic parameters (presence of blood vessels, inflammatory reaction, and collagen deposition) by a quantitative analysis. The Student paired t test was used for continuous variables, and the scores were compared through the chi-square test.

RESULTS

Both materials were structurally homogeneous and free from inflammatory cells or blood vessels (G1). In 3-month samples (G2), CEC areas were densely invaded by fibroblasts and blood vessels. Dx areas were fragmented but still homogeneous and free from cells or blood vessels. Samples from 3 and 11 months showed a significant difference in favor of CEC especially concerning preservation of material in the implant site, as well as the presence of neovascularization. This experimental study represents a positive outcome in terms of reflux resolution in the long term. Further studies may be necessary to confirm its efficacy when in clinical use.

CONCLUSION

The CEC exhibited low inflammatory response and integrated with the host tissue better than Dx in the long-term follow-up.

The use of polyacrylate-polyalcohol copolymer hydrogel in the endoscopic treatment of primary vesicoureteral reflux in children

BACKGROUND/PURPOSE

It is still under discussion which is the best tissue augmenting substance for the endoscopic treatment of children with vesicoureteral reflux (VUR). We describe our preliminary experience (September 2009-November 2011) with polyacrylate-polyalcohol copolymer hydrogel (PPCH).

METHODS

This is an observational, descriptive, prospective study which included 81 female and male patients (age 1-14 years) diagnosed with unilateral (n=45) and bilateral (n=36) primary VUR comprising a total of 117 refluxing renal units (RRU). Complex cases were excluded from the study. All patients were clinically and radiologically evaluated and those who met the inclusion criteria were treated endoscopically with a single subureteral injection of PPCH by a single surgeon. 11 patients (13.5%) had a pathological 99mTc-DMSA before treatment. The volume of injected product was measured in all cases. Results were considered successful if 6months postinjection, conventional voiding cystourethrogram (VCUG) revealed VUR was cured (Grade 0). Follow-up ranged from 7 to 32months.

RESULTS

The overall resolution rate based on the number of RRUs studied was 92.3% (108/117). The mean injected volume of PPCH per patient was 0.6ml. One patient with obstructive anuria required vesicoureteral reimplantation. Other complications were persistent, self-limiting hematuria (n=2); lumbar pain (n=4) and urinary tract infection with normal VCUG (n=4).

CONCLUSIONS

Our short term data show PPCH provides a high level of reflux resolution in selected patients. Long term follow-up is required.

Significance of an endoscopically injected nodule detected on ultrasound as a predictive factor for the resolution of vesicoureteral reflux

Endoscopic treatment of vesicoureteral reflux (VUR) is feasible in pediatric patients. As endoscopic injection has a lower success rate than ureteral reimplantation, a postoperative voiding cystourethrogram (VCUG) is usually performed. The present study evaluated whether the presence of a nodule on noninvasive ultrasound could predict the resolution of VUR and replace invasive VCUG. Patients who received an injection of endoscopic bulking agent for VUR from January 2005 to December 2010 were evaluated retrospectively. It was evaluated whether a nodule, an echogenic mass lesion distinguished from the bladder at the ureteral orifice, was present on the ultrasound one month postoperatively. The success of the injection in the group with nodules was compared with that of the group without nodules by VCUG 3 months postoperatively. A total of 149 patients (220 ureters) met the inclusion criteria. The mean age at surgery was 3.5 years (range, 0.6–18 years). The overall success rate was 73.2%. A nodule was present in 152 cases (69.1%). The group with nodules had a higher success rate than the group without nodules (84.2%, 128/152 vs. 48.5%, 33/68, respectively; P<0.001). According to multivariate analysis, injection nodules were a predictive factor for the success of the endoscopic injection (odds ratio, 6.050; P<0.001). The failure rate increased with increasing injection volume. The sensitivity of sonographic injection nodules for predicting success was 79.5% and the specificity was 59.3%. To conclude, the presence of a postoperative nodule can predict the resolution of VUR.

Endoscopic treatment of vesicoureteral reflux in pediatric patients

Endoscopic treatment is a minimally invasive treatment for managing patients with vesicoureteral reflux (VUR). Although several bulking agents have been used for endoscopic treatment, dextranomer/hyaluronic acid is the only bulking agent currently approved by the U.S. Food and Drug Administration for treating VUR. Endoscopic treatment of VUR has gained great popularity owing to several obvious benefits, including short operative time, short hospital stay, minimal invasiveness, high efficacy, low complication rate, and reduced cost. Initially, the success rates of endoscopic treatment have been lower than that of open antireflux surgery. However, because injection techniques have been developed, a recent study showed higher success rates of endoscopic treatment than open surgery in the treatment of patients with intermediate- and high-grade VUR. Despite the controversy surrounding its effectiveness, endoscopic treatment is considered a valuable treatment option and viable alternative to long-term antibiotic prophylaxis.

Prospective study using a new bulking agent for the treatment of vesicoureteral reflux: polyacrylamide hydrogel

PURPOSE

Vesicoureteral reflux is frequently diagnosed in the pediatric population. Endoscopic treatment has become a popular form of first-line therapy. Available products offer good short-term success rates. However, the cost of these injected implants is an issue. We evaluated the success of endoscopic treatment for vesicoureteral reflux using polyacrylamide hydrogel.

MATERIALS AND METHODS

We performed a single center, single surgeon, prospective, off-label study using polyacrylamide hydrogel to treat vesicoureteral reflux. All patients underwent endoscopic subureteral double hydrodistention implantation technique injection followed by renal ultrasound and voiding cystourethrogram at 3 months postoperatively to confirm the absence of de novo hydronephrosis and correction of vesicoureteral reflux (grade 0).

RESULTS

A total of 40 patients (69 refluxing ureters) underwent polyacrylamide hydrogel injection. Median age at surgery was 50 months. Bilateral reflux was identified in 29 patients (73%). Nine patients had duplex systems, 2 with reflux into both moieties. Reflux was graded using the International Reflux Study in Children grading system, with grade I seen in 9 ureters, II in 17, III in 20, IV in 18 and V in 5. Mean volume injected was 1.1 ml. Success rate for grade I to III vesicoureteral reflux at 3 months after a single treatment was 87%, and the overall success for all grades was 81.2%.

CONCLUSIONS

Off-label use of polyacrylamide hydrogel injection therapy for primarily low grade vesicoureteral reflux demonstrates that the technique and short-term success rates are comparable to the most popular bulking agent, dextranomer/hyaluronic acid. These results suggest that further trials comparing polyacrylamide hydrogel and dextranomer/hyaluronic acid would be worthwhile.

The influence of ureteral orifice configuration on the success rate of endoscopic treatment of vesicoureteral reflux

Background:

To investigate the effect of polyacrylate polyalcohol copolymer (Vantris) injection for the correction of VUR in children according to ureteral orifice shape and VUR grade.

Materials and Methods:

Forty children (29 girls and 11 boys) with 61 renal refluxing units (RRU) and primary VUR underwent endoscopic correction of their reflux, using Vantris. Under general anesthesia, routine cystoscopy was performed and ureteral orifice configuration and dynamic hydro distention grade were determined. The injection technique was STING, HIT or a combination of them. Ultrasound scan was performed one and 3 months after injection and radionuclide cystography (RNC) was performed 3 months after the operation.

Results:

The mean volume of injected Vantris was 0.62 cc. Reflux was corrected in 52 (85.2%) of the 61 RRU after single injection and this equates reflux correction in 37 of the 40 patients. No significant correlation was observed between ureteral orifice shape and VUR correction rate.

Conclusions:

Our results showed that there was no correlation between the ureteral orifice configuration and the success rate of endoscopic surgery for VUR in short term.

Observational, medical or surgical management of vesicoureteric reflux

The clinical management of vesicoureteric reflux includes observational, medical and surgical procedures. The choice of management is often a joint decision made between the paediatric nephrologist and urologist. The use of prophylactic antibiotics has become increasingly debated. In recent years, the surgical treatment of reflux (including endoscopic intervention or ureteral reimplantation) has mainly been limited to cases of high-grade reflux. There are several important risk factors that influence the final outcome which need to be identified and treated. The aim of reflux management is no longer to treat imperatively, but rather to avoid renal damage. It is perhaps time to revise the classic saying 'diagnosed reflux - treated reflux' with a new objective 'diagnosed reflux - evaluated reflux'.

CONCLUSION

The management and follow-up of childhood reflux is a joint decision between the paediatric urologist and nephrologist and should be decided on a case-by-case basis.

Endoscopic treatment of vesicoureteral reflux--a 20-year follow-up

Endoscopic reflux therapy has gained more and more popularity, and the use of this method is increasing. These imaging patterns (well known by pediatric radiologists) should be known by the general radiologist as the first young patients treated 20 years ago are now adults.

Durability of antireflux effect of ureteral reimplantation for primary vesicoureteral reflux: findings on long-term cystography

OBJECTIVE

To evaluate the long-term durability of successful ureteral reimplantation (UR) for vesicoureteral reflux (VUR) through a review of late cystography (LC) findings.

MATERIALS AND METHODS

We performed a retrospective chart review of all children with primary VUR who underwent successful open UR (grade 0 VUR into the reimplanted ureter[s] on initial cystogram) at our institution from January 1990 to December 2002. We identified successful UR patients who underwent LC ≥ 1 year after UR and reviewed the results for the presence of recurrent VUR into the reimplanted ureter(s).

RESULTS

Seven-hundred ninety-four patients underwent successful open UR for primary VUR, of whom 60 (7.6%) had a subsequent LC. Preoperative VUR grade was ≤ II in 20 (34.5%) and ≥ III in 38 (65.5%). Median age at UR was 3.5 years (IQR 1.3-6.2 years); 51 (85%) were female. UR was intravesical in 45 (75%) and bilateral in 19 (32%). LC was performed at a median of 38.7 months after UR (IQR 19.6-66.1 months). Indication for LC was febrile urinary tract infection (UTI) in 16 (27%), nonfebrile UTIs in 15 (25%), follow-up of contralateral VUR in 16 (27%), and other clinical indications in 13 (21%). The recurrence rate was 0%; of the 79 reimplanted ureters, 100% (95% CI 95.4-100) had no VUR (grade 0).

CONCLUSION

Among children who underwent successful open UR for primary VUR, there was no VUR recurrence on extended follow-up. This suggests that the late durability of open antireflux surgery is excellent.