Late Ureteral Obstruction After Injection of Dextranomer/Hyaluronic Acid Copolymer

Endoscopic treatment of primary vesicoureteral reflux in children with two different bulking agents, high success and low complication rates: Comparison of Dexell and Vantris

INTRODUCTION AND OBJECTIVES

To compare the results in terms of efficacy and safety of the endoscopic management for vesicoureteral reflux (VUR) in two different standardized primary VUR cohorts treated with Dexell and Vantris.

PATIENTS

128 refluxing renal units (RRU) in 87 patients with primary VUR (64 females, 23 males). Patients with secondary VUR and severe bladder and bowel dysfunction were excluded. A total of 22 continent children with mild bladder-bowel dysfunction underwent bladder-bowel training before the implantation. All procedures were performed in the presence of sterile urine using a conventional subureteral transurethral injection technique.

RESULTS

There were no statistically significant differences between groups in terms of mean age, sex, RRU side, ^99mTc-DMSA uptake, and reflux grade. The overall resolution rates based on the number of RRUs for up to three endoscopic treatments were 80% (56/70) in Dexell group and 94.8% (55/58) in Vantris group (P = .012). No postoperative recurrences or vesicoureteral junction obstructions were seen in any group.

CONCLUSIONS

Dexell and Vantris provided an effective and safe endoscopic VUR treatment in the early and mid-term follow up of children with primary VUR. The effectiveness of these substances, which can produce different mass effects with different particle sizes, in safe VUR resolution, needs further investigations.

Endoscopic treatment of primary vesicoureteral reflux in children with two different bulking agents, high success and low complication rates: comparison of Dexell and Vantris

INTRODUCTION AND OBJECTIVES

To compare the results in terms of efficacy and safety of the endoscopic management for vesicoureteral reflux (VUR) in two different standardized primary VUR cohorts treated with Dexell and Vantris.

PATIENTS

128 refluxing renal units (RRU) in 87 patients with primary VUR (64 females, 23 males). Patients with secondary VUR and severe bladder and bowel dysfunction were excluded. A total of 22 continent children with mild bladder-bowel dysfunction underwent bladder-bowel training before the implantation. All procedures were performed in the presence of sterile urine using a conventional subureteral transurethral injection technique.

RESULTS

There were no statistically significant differences between groups in terms of mean age, sex, RRU side, 99mTc-DMSA uptake, and reflux grade. The overall resolution rates based on the number of RRUs for up to three endoscopic treatments were 80% (56/70) in Dexell group and 94.8% (55/58) in Vantris group (p = 0.012). No postoperative recurrences or vesicoureteral junction obstructions were seen in any group.

CONCLUSIONS

Dexell and Vantris provided an effective and safe endoscopic VUR treatment in the early and mid-term follow up of children with primary VUR. The effectiveness of these substances, which can produce different mass effects with different particle sizes, in safe VUR resolution, needs further investigations.

Incidence and risk factors for calcification after dextranomer/hyaluronic acid (Dx/HA) copolymer injection for vesicoureteral reflux

INTRODUCTION

Since the first case of dextranomer/hyaluronic acid (Dx/HA) implant calcification in 2008, concern about the long-term sequelae of Dx/HA injection has been growing. According to previous reports, the incidence of Dx/HA calcification 4 years after injection would be around 2%.

AIM

The primary aim was to estimate the incidence of Dx/HA implant calcification after endoscopic treatment of vesicoureteral reflux in pediatric patients. Secondary objectives were to establish risk factors and to perform a survival analysis after Dx/HA injection.

STUDY DESIGN

Patients undergoing Dx/HA endoscopic injection from 2007 to 2014 were prospectively registered. The database included clinical, surgical and radiological outcomes. Patients that showed Dx/HA implant calcification during follow-up were compared to those who did not. Univariable and survival statistical analyses were performed.

RESULTS

30 implants calcified over 355 ureters endoscopically treated. Age at first treatment was lower in patients with implant calcification (2.4 ± 1.3 years vs 3.6 ± 2.5 years; p < 0.005). The risk of implant calcification was 8.45% (95% CI: 5.96-11.85%). Median follow-up was 7.6 years (IQR: 5.2-9.5). The incidence rate was 12.06 cases per 1000 ureters-year. The period of highest hazard of implant calcification was between 3 and 5 years after injection. The only risk factor related to implant calcification was the age at first injection: relative risk of implant calcification was 4.4 (95% CI: 1.6 to 12.4; p = 0.002) for patients first treated before the age of 3.5 years.

DISCUSSION

The risk and the incidence rate of Dx/HA implant calcification were higher than previous data. The period of highest hazard and detection of implant calcification were consistent with previous reports. Patients first treated before the age of 3.5 had shorter survival time without implant calcification. These are the first data about risk factors and survival function of Dx/HA implant calcification. However, our conclusions about the clinical significance of Dx/HA implant calcification were limited because the patients with implant calcification were asymptomatic. Further studies with larger sample and longer follow-up should confirm the clinical significance and life-long tendency of Dx/HA implant calcification.

CONCLUSIONS

The risk and the incidence rate of Dx/HA implant calcification were higher than expected. The hazard of calcification was higher between 3 and 5 years after injection. The risk was especially higher in patients treated before the age of 3.5. Caution should be taken not to confuse implant calcifications with ureteric stones. A 5-year follow-up would set a better understanding of the actual incidence and clinical significance of implant calcification.

Long-Term Clinical Outcomes and Parental Satisfaction After Dextranomer/Hyaluronic Acid (Dx/HA) Injection for Primary Vesicoureteral Reflux

Purpose: Endoscopic dextranomer/hyaluronic acid (Dx/HA) injection is a common treatment for vesicoureteral reflux (VUR) with excellent reported short-term clinical success rates. Long-term outcomes are less well-defined. We assessed long-term outcomes and parental satisfaction after Dx/HA injection for primary VUR with >5-year follow-up. Materials and Methods: Families of all patients who underwent Dx/HA injection for primary VUR at our institution between 2008 and 2012 were contacted for telephone interview. Data collected by phone included parental satisfaction and presence and severity of UTIs pre-operatively and post-operatively. Patient demographics, radiographic VUR data, need for secondary surgery, and surgical indications were obtained through chart review. Results: Five hundred and seventy-five patients underwent Dx/HA injection for primary VUR between 2008 and 2012. Ninety-nine (17.2%) of these patients' parents were successfully contacted and interviewed. Median follow-up time from surgery to survey was 8.4 (IQR 6.8-9.6) years. Secondary surgery was performed in 13/99 (13.1%), most commonly repeat Dx/HA injection. Seven patients (7.1%) underwent secondary Dx/HA injection for persistent VUR without UTIs at a median of 0.35 (IQR 0.33-0.77) years post-operatively. Five patients (5.1%) underwent Dx/HA injection (n = 3) or ureteral reimplantation (n = 2) for VUR with febrile UTIs (fUTIs) at a median of 2.2 (IQR 1.3-5.1) years. One patient had ureteral reimplantation for symptomatic obstruction 2.8 years after initial surgery. Only 3/99 (3.0%) required open or laparoscopic surgery after Dx/HA injection. Eighty-three families (84.7%) reported ≥1 fUTIs pre-operatively. Of these, only 9/83 (10.8%) reported fUTIs post-operatively, for an overall clinical success rate of 89.2%. Clinical success was 93.1% in patients whose pre-operative fUTIs were treated outpatient and 80.0% in those hospitalized at least once for fUTI treatment pre-operatively. Ninety-four percent of parents were highly satisfied, 2.4% partially satisfied, and 3.5% dissatisfied. Conclusions: Endoscopic injection with Dx/HA for primary VUR appears to have good long-term clinical success rates and high parental satisfaction, mirroring our previously reported short-term results. Post-operative ureteral obstruction is rare but may occur years post-operatively, justifying initial sonographic surveillance, and repeat imaging in symptomatic patients.

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.