Endoscopic injection of dextranomer hyaluronic acid copolymer for the treatment of vesicoureteral reflux in duplex ureters

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.

Is lower urinary tract surgery without upper pole heminephrectomy safe and effective in the long-term treatment of duplex system ureterocele?

Objective:

The study aimed to retrospectively evaluate postoperative results of patients with duplex system ureterocele (DSU) who underwent endoscopic ureterocele incision (UI), lower urinary tract reconstruction (LUTR) or both, and investigate the necessity of upper pole heminephrectomy (UPH) in ureterocele treatment.

Patients and methods:

In total, 44 patients with DSU who were operated on in December 2005 and December 2018 were evaluated for patient characteristics, ureterocele location, differential renal function (DRF), vesicoureteral reflux (VUR), postoperative incontinence, proteinuria, hypertension and urinary tract infection (UTI).

Results:

UI was performed in 27 of 44 cases (61.3%) as the first-line treatment. Ten of them (37%) had no urinary infection or renal function loss at a mean of 3 years (1.5–7 years). LUTR was needed in 17 patients after UI due to VUR in 14 patients and bladder outlet obstruction (BOO) in 3 patients. In total, 34 patients who underwent LUTR, proteinuria or incontinence were not detected in the mean 6 years’ follow-up. Thirty-three patients (97%) had identical renal scans and similar DRF before and after the operation. No patient underwent UPH.

Conclusion:

UI must be considered the first-line treatment in DSU in infancy. In older patients, especially with VUR, LUTR is effective and safe and UPH mostly is not necessary.

Level of evidence:

4

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.

Subureteral Injection with Small-Size Dextranomer/Hyaluronic Acid Copolymer: Is It Really Efficient?

The aim of this study was to evaluate the clinical results of patients with vesicoureteral reflux, which were treated with subureteral injection of small-size (80–120 μm) dextranomer/hyaluronic acid copolymer (Dx/HA). Data of 75 children (105 renal units) who underwent STING procedure with small-size Dx/HA for the treatment of vesicoureteral reflux (VUR) in our clinic between 2008 and 2012 were retrospectively analyzed. Preoperative reflux grade and side, injection indication, postoperative urinary infections and urinary symptoms, voiding cystourethrogram, and renal scintigraphy results were evaluated. The success rate of the procedure was 100% in patients with grades 1 and 2 reflux, 91% in patients with grade 3 reflux, and 82.6% in patients with grade 4. Overall success rate of the treated patients was 97%. Endoscopic subureteric injection with Dx/HA procedure has become a reasonable minimally invasive alternative technique to open surgery, long-term antibiotic prophylaxis, and surveillance modalities in treatment of VUR in terms of easy application, low costs and complication rates, and high success rates. Injection material composed of small-size dextranomer microspheres seems superior to normal size Dx/HA, together with offering similar success with low cost.

Dextranomer/hyaluronic acid endoscopic injection is effective in the treatment of intermediate and high grade vesicoureteral reflux in patients with complete duplex systems

PURPOSE

Endoscopic subureteral injection of dextranomer/hyaluronic acid has become an established alternative to long-term antibiotic prophylaxis or surgical treatment for vesicoureteral reflux. We evaluated the effectiveness of endoscopic injection of dextranomer/hyaluronic acid in intermediate and high grade vesicoureteral reflux in patients with complete duplex collecting systems.

MATERIALS AND METHODS

A total of 123 children underwent endoscopic correction of intermediate or high grade vesicoureteral reflux using injection of dextranomer/hyaluronic acid into complete duplex systems between 2001 and 2010. Vesicoureteral reflux was diagnosed by voiding cystourethrogram, and dimercapto-succinic acid scan was performed to evaluate the presence of renal scarring. Followup ultrasound and voiding cystourethrogram were performed 3 months after the outpatient procedure and renal ultrasound thereafter every 2 years. Mean followup was 6.7 years.

RESULTS

Complete duplex systems were unilateral in 110 patients and bilateral in 13. Reflux severity in the 136 refluxing units was grade II in 1 (0.7%), III in 52 (38.2%), IV in 61 (44.9%) and V in 22 (16.2%). Dimercapto-succinic acid scan revealed renal functional abnormalities in 63 children (51.2%). Vesicoureteral reflux resolved after the first endoscopic injection of dextranomer/hyaluronic acid in 93 ureters (68.4%), after a second injection in 35 (25.7%) and after a third injection in 8 (5.9%). Febrile urinary tract infection developed in 5 patients (4.1%) during followup. No patient required ureteral reimplantation or experienced significant complications.

CONCLUSIONS

Our results confirm the safety and efficacy of endoscopic injection of dextranomer/hyaluronic acid in eradicating intermediate and high grade vesicoureteral reflux in patients with complete duplex systems. We recommend this minimally invasive, 15-minute outpatient procedure as a viable option for treating intermediate and high grade vesicoureteral reflux in patients with complete duplex collecting systems.

Laparoscopic ureteroureterostomy in children with a duplex collecting system plus obstructed ureteral ectopia

One of the complex upper urinary tract anomalies is a duplicated collecting system. In cases with a functioning upper moiety, ureteroureterostomy (UU) is the preferred operation to redirect the urine to the normal collecting system. Although open UU is a well-described operation, experience with laparoscopic repair pediatric patients is scarce. We describe the successful application of laparoscopic UU in 2 children and suggest that laparoscopic UU for the duplicated collecting system is a promising minimally invasive procedure.

Urinary tract anomalies associated with high grade primary vesicoureteral reflux

BACKGROUND

Few studies have evaluated the significance of associated urological anomalies in vesicoureteral reflux (VUR). The aim of our study was to determine the incidence of associated urological anomalies in patients with high grade VUR and to assess their impact on renal parenchymal scarring.

METHODS

We retrospectively reviewed the hospital records of 1,765 consecutive cases diagnosed with high grade VUR (Grade III-V) at our hospital between 1998 and 2010. The diagnosis of VUR was made by a voiding cystourethrogram (VCUG). Renal scarring was evaluated by dimercapto-succinic acid (DMSA) scintigraphy and classified into three groups: mild (focal defects in uptake between 40 and 45%), moderate (uptake of renal radionuclide between 20 and 40%), and severe (shrunken kidney with relative uptake <20%). All associated urological anomalies were diagnosed by ultrasound or VCUG or DMSA scan.

RESULTS

Associated urological anomalies were present in 229 (13%) children. There were 87 boys and 142 girls. Duplex kidney was the main associated anomaly occurring in 148 (64.6%) of the 229 patients. Other anomalies were: bladder diverticulum in 29, solitary kidney in 12, ureterocele in 13, hypospadiasis in 11, pelviureteric junction obstruction in 9, malrotated kidney in 3, horseshoe kidney in 2, crossed fused ectopia in 1 and renal cyst in 1. DMSA scan revealed renal scarring in 105 (47.7%) of the 220 children who had a DMSA scan. 75 (50.7%) children with duplex kidneys showed renal scarring.

CONCLUSION

Associated urological anomalies occur commonly in patients with high grade VUR. Our data shows that nearly half of the patients with VUR and associated urological anomalies have renal scarring. Early recognition and treatment of VUR patients with associated urological anomalies may decrease the risk of renal parenchymal damage.

An all-endo Approach to Complete Ureteral Duplications Complicated by Ureterocele and/or Vesicoureteral Reflux: Feasibility, Limitations, and Results

Purpose. Totally endoscopic management (all-endo) of patients with a duplicated renal system (DS) associated with severe vesicoureteral reflux (VUR) or obstructive ureterocele (UC) is an attractive alternative to traditional open procedures. The authors discuss feasibility and results of an all-endo approach on a consecutive series of patients. Methods. From 1999 to 2009, all patients with a complete DS associated with UC and/or VUR were proposed for primary all-endo approach. UC puncture was performed using a 3 Fr Bugbee electrode. Deflux (dextranomer/hyaluronic acid copolymer) injection was administered for VUR. The need for secondary surgery was evaluated on followup. Results. Of the 62 patients recruited, 46 were treated using a primary all-endo approach and 16 patients received no treatment. Of the 46 treated patients with 56 affected renal units, 32 (97%) UCs collapsed following puncture and 29 (63%) VURs were resolved or downgraded. Secondary VUR occurred in 13 (39%) renal units. Secondary surgery was performed on 23 (41%) renal units. Conclusion. The all-endo approach for VUR in DS is an effective therapeutic option. UC collapse was achieved by puncture in most of the patients; secondary VUR was the main complication in a small group of extravesical UC.

Is a third endoscopic treatment for vesicoureteral reflux indicated if previous attempts have failed?

OBJECTIVE

To evaluate the efficacy of a third endoscopic injection to correct vesicoureteral reflux (VUR).

PATIENTS AND METHODS

This was a prospective study of 605 patients, of whom 42 (6.4%), involving 44 (4%) ureteral units, received a third injection. The results were analysed regarding VUR grade and aetiology, substance used, volume, location and morphology of the mound, presence of poor prognostic factors, the urologist's experience, and complications.

RESULTS

The treatment resolved the VUR in 38 (86.4%) units, 22 of primary cause (91.6%) and 16 with anatomical/functional abnormalities (80%) (no significant difference; P = 0.26). There was also no significant difference in success rate with regard to the substance injected (P = 0.23), the degree of VUR (P = 0.76) or the volume injected (P = 0.17). The success rate was higher (96.9%) if a less experienced urologist had performed the previous procedure versus a more experienced urologist (54.5%), and this difference was significant (P < 0.005). There was one complication (haematuria) (2.3%).

CONCLUSION

Third treatment presents a similar efficacy to first and second treatments, with a very low rate of complications, and could be indicated before open surgery.

Dextranomer/hyaluronic injection for the management of vesicoureteric reflux in complete ureteral duplication: should age and gender be factors in decision making?

BACKGROUND AND PURPOSE

The injection of dextranomer/hyaluronic acid (DHA) has become an accepted treatment for children with vesicoureteral reflux (VUR). Complete ureteral duplication has been considered by some practitioners as counterindication for its use. We reviewed the Texas Children's Hospital (TCH) records for children with complete ureteral duplication who were treated with DHA for VUR.

METHODS

We searched medical records at TCH for patients with a preoperative diagnosis of complete ureteral duplication who had undergone DHA injection between January 1, 2001, and October 15, 2008. Operative notes, imaging studies, and clinic notes were reviewed.

RESULTS

In this period, 28 kidneys in 24 children were treated. The average grade of reflux before injection was 3.44 (range 1-5). First injection resolution of reflux was 57% with an increase to 73% after a second injection with an average volume of DHA of 1.05 mL. New contralateral VUR developed postinjection in three (15%) children with unilateral VUR. There were no perioperative complications. The average age of the children who were treated was 41.4 months. Mean follow-up was 45.94 months. Success of DHA injection tended to be higher in girls (65%) and older children.

CONCLUSIONS

High levels of success can be achieved with DHA injection in children with complete ureteral duplication. DHA injection is more likely to be successful for older girls with VUR and complete ureteral duplication. If initial injection does not result in VUR resolution, a second injection offers an opportunity for improved success. For physicians and families who are seeking an alternative to open surgical management, DHA represents an attractive option for selected children with complete ureteral duplication.

Dextranomer/hyaluronic acid for pediatric vesicoureteral reflux: systematic review

OBJECTIVE

Published success rates of dextranomer/hyaluronic acid (Dx/HA) injection for pediatric vesicoureteral reflux (VUR) vary widely. Our objective of this study was to assess whether underlying patient or study factors could explain the heterogeneity in reported Dx/HA success rates.

METHODS

We searched the Cochrane Controlled Trials Register and Medline, Embase, and Scopus databases from 1990 to 2008 for reports in any language, along with a hand search of included study bibliographies. Articles were assessed and data abstracted in duplicate, and differences were resolved by consensus. Conflict of interest (COI) was determined by published disclosure. Meta-regression was performed to adjust for patient as well as study-level factors.

RESULTS

We identified 1157 reports, 89 of which were reviewed in full with 47 included in the pooled analysis. Of 7303 ureters that were injected with Dx/HA, 5633 (77%) were successfully treated according to the authors' definition. Injection success seemed to vary primarily on the basis of the preoperative reflux grade. After adjustment for VUR grade, other factors, such as the presence or absence of COI disclosure, were not significant. Studies were markedly heterogeneous overall.

CONCLUSIONS

The overall per-ureter Dx/HA success rate was 77% after 3 months, although success rates varied widely among studies. Increased VUR grade negatively affected success rates, whereas COI, patient age, and injected Dx/HA volume were not significantly associated with treatment outcome after adjustment for VUR grade. There is a significant need for improved reporting of VUR treatments, including comparative studies of Dx/HA and other VUR treatments.

Predicting success in the endoscopic management of pediatric vesicoureteral reflux

Vesicoureteral reflux is a common cause of pediatric morbidity. Though traditionally managed using a limited number of therapeutic modalities, the last decade has witnessed countless surgical innovations for treating reflux. A major force behind this innovation is the increasing use of endoscopic injection, which currently constitutes nearly half of all anti-reflux procedures performed in the United States. However, published success rates for injection vary dramatically. Despite a relative lack of comparative data, multiple studies have attempted to define the most important prognostic factors for injection success. This article is an attempt to summarize these findings.

Endoscopic treatment of vesicoureteral reflux using dextranomer hyaluronic acid copolymer

Vesicoureteral reflux (VUR) is a common urinary tract anomaly. Treatment is performed to minimize the risk of febrile urinary UTIs that may result in renal scarring. The endoscopic use of dextranomer hyaluronic acid copolymer has been gaining popularity as an alternative to the traditional methods of open surgery and chronic antibiotic prophylaxis. The aim of this educational review was to present the trends, latest perspectives and surgical techniques regarding this newer method of treatment of VUR. Evolving techniques are described that have resulted in VUR cure rates that rival that of open ureteral reimplantation with minimal associated morbidity. These have proven to be effective in complex cases that were previously considered as contraindications for endoscopic treatment, including voiding dysfunction, duplex ureters, high-grade VUR and paraureteral diverticuli. It is recommended that open reimplantation be reserved for those children with ectopic ureters, megaureters that require tapering or secondary grade V VUR, and those who have failed two endoscopic injections. Future advances promise to standardize the injection technique, ensuring optimum needle placement for consistently successful injections.

Endoscopic treatment of vesicoureteral reflux with dextranomer/hyaluronic acid in children

PURPOSE

The goal of this review is to present current indications, injectable agents, techniques, success rates, complications, and potential future applications of endoscopic treatment for vesicoureteral reflux (VUR) in children.

MATERIALS AND METHODS

The endoscopic method currently achieving one of the highest success rates is the double hydrodistention-implantation technique (HIT). This method employs dextranomer/hyaluronic acid copolymer, which has been used in pediatric urology for over 10 years and may be at present the first choice injectable agent due to its safety and efficacy.

RESULTS

While most contemporary series report cure rates of greater than 85% for primary VUR, success rates of complicated cases of VUR may be, depending on the case, significantly lower. Endoscopic treatment offers major advantages to patients while avoiding potentially complicated open surgery. As the HIT method continues to be applied to complex cases of VUR and more outcome data become available, the indication for endoscopic treatment may exceed the scope of primary VUR.

CONCLUSIONS

Endoscopic injection is emerging as the treatment of choice for VUR in children.