What are the most powerful determinants of endoscopic vesicoureteral reflux correction? Multivariate analysis of a single institution experience during 6 years

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.

Does pre-fellowship experience alter success rates of endoscopic treatment of vesicoureteral reflux during pediatric urology fellowship?

INTRODUCTION

Learning curve is a well-known factor that affects the success rate of endoscopic injection for vesicoureteral reflux (VUR).

OBJECTIVE

To our knowledge, the significance of pre-fellowship training has not been studied. In the present study, our aim was to investigate the effect of pre-fellowship training on the endoscopic treatment success rates of pediatric urology fellows.

DESIGN

A total of 78 patients aged 2-16 years (132 renal units) who underwent subureteric injection for the treatment of primary VUR by four pediatric urology fellows between 2014 and 2020 were retrospectively evaluated. Fellows were grouped into two as experienced and non-experienced according to the presence of pre-fellowship experience (defined as a minimum of 20 procedures). Patients in both groups were divided into two subgroups as non-dilating (grade I-II) and dilating VUR (grade III-V). Also, the change in success rate throughout the fellowship was analyzed. HIT or Double HIT method was used in all interventions.

RESULTS

Experienced fellows carried out subureteric injection in 54 (40.9%) renal units while non-experienced fellows performed in 78 (59.1%). There was no success rate difference between experienced and non-experienced fellow groups in non-dilating VUR (100% vs. 88%, respectively p = 0.268), whereas the success rate of the experienced group was significantly higher in dilated VUR (78.9% vs. 50.9%, p = 0.006). Moreover, the amount of material used in the treatment of non-dilating VUR were similar between two fellow groups (0.6 ml vs. 0.6 ml, p = 0.500), while experienced group achieved higher success rates in dilating VUR by statistically significant less amount of injected volume (0.7 ml vs. 0.9 ml, p = 0.026).Overall complete VUR resolution rates were similar throughout the fellowship period in the experienced fellows (81.5% vs. 88.9%, p = 0.444), while it significantly increased in the non-experienced group implicating the completion of the learning curve (51.3% vs. 74.4%, p = 0.035).

DISCUSSION

There has been no published reports on the effect of pre-fellowship experience on subureteric injection success. While many researchers reported on the importance of learning curve, various studies assessed the effect of injected volume on success rate implicating contradictory results. Furthermore, others indicated that the ideal technique providing accurate needle placement and obtaining proper depth during injection which is associated with surgical experience is more important than the injected volume in achieving success.

CONCLUSION

Our results implicate that similar success rates in non-dilating VUR can be achieved regardless of previous subureteric injection training. However, higher failure rates may be expected when the procedures are performed by non-experienced pediatric urology fellows at the beginning of their fellowship in dilating VUR.

Factors affecting endoscopic treatment’s failure for primary vesicoureteral reflux in the paediatric population

Objective:

The purpose of this study is to identify which factors could determine endoscopic therapy’s failure in the paediatric patients with primary vesicoureteral reflux (VUR).

Methods:

We reviewed data from patients who underwent endoscopic surgery for primary reflux. We performed a multivariate logistic regression analysis considering factors conditioning therapeutic failure. All the tests were performed considering significant values of p < 0.05. Statistical analysis was performed with the SPSS 19.0 program. Study sample was homogenised by just including patients with primary reflux and excluding both patients with secondary reflux and patients with functional lower urinary conditions.

Results:

A total of 96 patients were included for review. Median age at surgery was 28 months. The overall success rate of endoscopic surgery for vesicoureteral reflux was 57%. Female sex, age under 24 months at the time of surgical intervention and having suffered a urinary tract infection (UTI) despite antibiotic prophylaxis are statistically significant risk factors for therapy failure.

Conclusions:

Nonetheless, differences between series could explain these differences in success rates. The lack of standardisation of the definition of ‘success’, the heterogeneity of patients included, and variables such as the degree of reflux, the presence of dysfunctional voiding, age or follow-up make it difficult to compare the success rate between series. Therefore, homogenisation of study samples assessing the evolution of primary reflux and response to endoscopic therapy is warranted.

Level of evidence:

Not applicable

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.

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.

Avoiding routine postoperative voiding cystourethrogram: Predicting radiologic success for endoscopically treated vesicoureteral reflux

INTRODUCTION

Variability in the success rates for the endoscopic correction of vesicoureteral reflux (VUR) has prompted a debate regarding the use of routine postoperative voiding cystourethrogram (VCUG). This study examines the predictive performance of intraoperative mound morphology (IMM) and the presence of a postoperative ultrasound mound (PUM) on radiologic success, as well as investigates the role of using these two predictive factors as a composite tool to predict VUR resolution after endoscopic treatment.

METHODS

This retrospective study included children with primary VUR who underwent endoscopic correction with a double hydrodistension-implantation technique (HIT) and dextranomer/hyaluronic acid copolymer. IMM was assessed intraoperatively. The presence of a PUM and VUR resolution were assessed by postoperative ultrasound (US) and VCUG, respectively. Radiologic success was defined as VUR resolution.

RESULTS

A total of 70 children (97 ureters) were included in the study. The overall radiologic success rate was 83.5%. There was no statistically significant association between radiologic success and IMM (85.2% with excellent and 87.5% with "other" morphology; p=0.81). The sensitivity and specificity of PUM for radiologic success in this study was 98% and 71%, respectively, while the sensitivity and specificity of the combined prediction model were 81.9% and 85.7%, respectively.

CONCLUSIONS

We objectively demonstrated that IMM was a poor predictor of radiologic success and should be used with caution. In addition, the performance of a combined prediction model was inferior to the presence of a PUM alone. As such, selective use of postoperative VCUG may be guided solely by the presence of a PUM.

Reflux Timing Is a Predictor of Successful Endoscopic Treatment of Vesicoureteral Reflux

OBJECTIVE

To determine whether vesicoureteral reflux (VUR) that occurs during either the filling or voiding phase on voiding cystourethrogram (VCUG) has prognostic significance on successful endoscopic treatment.

MATERIALS AND METHODS

A retrospective review was performed of 299 patients (438 ureters) with VUR who underwent endoscopic treatment with dextranomer/hyaluronic acid copolymer (Deflux) at a single institution from 2010 to 2013. Success was defined as absence of VUR on 3-month follow-up VCUG. Preoperative VCUGs were analyzed to determine whether the onset of VUR occurred during the filling or voiding phase. Predictor variables to determine success were analyzed, with a specific focus on VUR timing.

RESULTS

Success rate was 319/438 (72.8%) by ureter and 202/299 (67.6%) by patient. Reflux was seen during the filling and voiding phases in 290 and 148 ureters, respectively. Success rate was 203/290 (78%) for filling VUR and 116/148 (70%) for voiding VUR. Univariable analysis revealed voiding VUR had significantly increased odds of success (odds ratio [OR] 3.2, P = .049), while high-grade reflux (OR 0.53, P = .005) had significantly decreased odds of success. Multivariable analysis showed that voiding VUR (OR 3.2, P = .005) had significantly higher odds of success while those with high grade reflux (OR 0.42, P = .017) had significantly decreased odds of success.

CONCLUSION

The timing of VUR on preoperative VCUG appears to be an important independent predictor of successful endoscopic treatment of VUR. This has important clinical considerations when selecting VUR patients who would be best candidates for endoscopic treatment.

Endoscopic injection for primary vesicoureteric reflux: Predictors of resolution and long term efficacy

AIM

We investigated the efficacy of endoscopic-Deflux-injection in treating primary-vesicoureteric-reflux (VUR) and identified factors to predict resolution.

MATERIALS AND METHODS

Records of children treated with Deflux for primary-VUR from 1995 to 2016 were reviewed, and outcomes were investigated.

RESULTS

Eighty-eight ureters (35 bilateral, 18 unilateral) in 53 children underwent 124 injections. Thirty-five (66%) patients had single injection (13 unilateral, 22 bilateral). Fifteen (28%), two (37%), and one (2%) patients had two, three, and four injections, respectively. Overall success rate by ureters was 57% after single injection. Complete resolution occurred in 65% of ureters with VUR below grade III, 63% of grade III, 40% of grade IV, and 70% of grade V VUR. Four patients had reimplantation. The median follow up duration was 60months (range 20-216months). Univariate analysis showed that lower VUR grade (p=0.03) and absent renal scars (p=0.04) were statistically significant predictors of resolution. In multivariate analysis, absent renal scars were statistically significant (p=0.01).

CONCLUSION

We demonstrated efficacy of endoscopic-Deflux-injection as the first line treatment for primary-VUR. Absent renal scar and lower VUR grade were statistically significant predictors of resolution after single injection.

TYPE OF STUDY

Case-Control / Retrospective Comparative Study.

LEVEL OF EVIDENCE

Level III.

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.

VUR timing on VCUG as a predictive factor of VUR resolution after endoscopic therapy

BACKGROUND

The timing of reflux onset on VCUG (VUR timing) has been considered a predictive factor of spontaneous resolution in VUR children. While the voiding reflux is associated with a greater rate of spontaneous resolution, the filling reflux is more likely to require surgical intervention. However, the VUR timing in children with primary VUR has not been evaluated with regard to the prognostic value of endoscopic therapy. The aim of this study was to evaluate the effect of VUR timing on the surgical outcome after endoscopic therapy for primary VUR.

METHOD

We retrospectively reviewed the medical records of 94 primary VUR patients who underwent endoscopic injection for their initial surgical management. Radiologic success was defined as grade I or less on VCUG at 3-6 months following endoscopic therapy. We allocated patients to a filling reflux group or a voiding reflux group on the basis of their most recent preoperative VCUG. We evaluated the patients' demographics and outcomes after endoscopic therapy according to VUR timing. Predictive factors for radiologic success were analyzed using a multivariate logistic regression model.

RESULTS

Of the 94 children (136 ureters), 68 (101 ureters) were classified as the filling reflux group and 26 (35 ureters) were placed in the voiding reflux group. The preoperative VUR grade in the filling reflux group was significantly higher than that in the voiding reflux group (p = 0.001). Radiologic success was observed in 56.44% (57/101 ureters) in the filling reflux group and in 88.57% (31/35 ureters) in the voiding reflux group (p = 0.001). Multivariate analysis showed that VUR grade and VUR timing on VCUG were predictive factors of radiologic success after endoscopic therapy (p = 0.001 and p = 0.005).

CONCLUSIONS

Despite the clinical importance of VUR timing, no studies have investigated the prognostic value of VUR timing for endoscopic therapy in primary VUR children. In this study, multivariate analysis revealed that the VUR grade and VUR timing on preoperative VCUG were significant predictors of success after endoscopic injection. Although the VUR grade is the most well-known factor that can affect the success of the procedure, VUR timing was a newly identified predictive factor. While patients with a filling reflux have lower success rates, patients with a voiding reflux were observed to show higher resolution rates after endoscopic injection. VUR timing on preoperative VCUG was found to be an independent predictive factor of VUR resolution after endoscopic therapy.

Is intraoperative surgeon's opinion an accurate tool to assess the outcome of endoscopic treatment for vesicoureteral reflux?

OBJECTIVE

Our experience in the endoscopic treatment of vesicoureteral reflux (VUR) has significantly increased during the last decade. To help develop diagnostic tests to check the success of this procedure, we evaluated the accuracy of surgeons' intraoperative observations as a predictor of treatment results.

METHOD

We performed a prospective study of patients with VUR who were endoscopically treated during 1 year (106 renal units). Patients' age and gender, laterality, material used, grade of reflux, presence of ureteral duplication or associated pathology, and morphology of ureteral orifice were recorded as predictive factors related to the success rate. Surgeon and assistant indicated at the end of the endoscopic procedure whether the VUR was cured or not for each renal unit. These estimations were compared with postoperative voiding cystourethrogram results.

RESULTS

Overall cure rate was 75.5%. Positive predictive value (PPV) for surgeon's opinion was 0.79 and negative predictive value (NPV) was 0.40. Statistical analysis demonstrated that the association between the surgeon's opinion and the cure rate was low with a Kappa value of 0.171 (p = 0.30). PPV of assistant's opinion was 0.80 and NPV was 0.40, with a Kappa value of 0.2 (p = 0.13). Concordance of surgeon and assistant's opinion resulted in PPV of 0.79 and NPV of 0.53 (Kappa = 0.261). Kappa value did not improve when surgeon's opinion was related to other factors such as the material employed, grade of reflux, presence of ureteral duplication or associated pathology and morphology of the ureteral orifice.

CONCLUSION

In our experience, surgeon's opinion is not an accurate tool to predict the outcome of endoscopic treatment of VUR.

Current medical diagnosis and management of vesicoureteral reflux in children

Vesico-ureteral reflux (VUR) is presented in approximately %1 of children and is associated with an increased risk of pyelonephritis and renal scarring. Despite its prevalence and morbidity, many aspects of VUR diagnosis and treatment are controversial. We objectively assessed the published data; the data base for many current diagnoses and treatment patterns of VUR is limited. Recent studies have focused on developed determination of VUR-related renal morbidity, improved stratification tools that children would benefit most from which VUR treatment option, and improved reporting of the long-term outcomes of VUR treatments in children who are at risk for VUR. In this review, the advances in the diagnosis and treatment of VUR will be accompanied by the current guidelines.

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.

Is the appearance of the dextranomer/hyaluronic acid mound predictive of reflux resolution?

PURPOSE

After endoscopic correction of vesicoureteral reflux, we correlated the appearance of the Deflux® mound with the outcome.

MATERIAL AND METHODS

We created an online survey based on 11 primary vesicoureteral reflux cases, including 6 failed and 9 successful procedures in a total of 15 renal units. Cases were selected randomly from our video library. All cases were performed by a single surgeon using the double hydrodistention implantation technique until a satisfactory mound was achieved and corrected. An online survey questionnaire was e-mailed to 234 members of the Society for Pediatric Urology. Each survey question contained a preoperative voiding cystourethrogram image as well as images of the ureteral orifice before and after injection. Respondents were asked to predict whether they thought that the appearance of the Deflux mound would be associated with successful reflux resolution on voiding cystourethrogram 3 months postoperatively. We analyzed the percent of correctly answered questions as well as the sensitivity, specificity and predictive value of the ability of experts to predict the outcome.

RESULTS

A total of 104 pediatric urologists responded to the survey. Overall, 66.4% of respondents predicted reflux resolution based on mound appearance, including 66% and 67% who correctly predicted success and failure, respectively. Mean outcome predictability per respondent was 66% (range 26% to 86%).

CONCLUSIONS

The appearance of the Deflux mound and lack of hydrodistention at the completion of the procedure are not reliable predictors of outcome. Based on this experience, postoperative voiding cystourethrogram is still required to truly determine reflux resolution.

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.

The impact of vesicoureteral reflux treatment on the incidence of urinary tract infection

Vesicoureteral reflux (VUR) is a heterogeneous disease and its management remains one of the most controversial topics in pediatrics. Management options include surveillance, antibiotics, and surgery. The approval of dextranomer/hyaluronic acid (DHA) as a bulking agent by the Food and Drug Administration was followed by wide acceptance of endoscopic techniques as a major tool in the management of reflux. Pyelonephritis rather than VUR is the most common cause of kidney damage in children. It should be emphasized that the primary goal of diagnosing and treating VUR should be preventing this complication. There are no sufficient data in the literature to address the impact of the different treatment modalities on the incidence of febrile urinary tract infections (feb-UTIs) denoting pyelonephritis, with very few studies evaluating endoscopic treatment in light of this clear and well-defined outcome. The fact that we can correct the anatomy at the vesicoureteral junction with a simple and relatively safe outpatient procedure does not justify offering it to all patients. In this review, we attempt to critically evaluate the available literature pertaining to the impact of different treatment modalities on reducing the incidence of febrile UTIs and kidney damage, with a special emphasis on endoscopic treatment.

Single injection results of endoscopic treatment of vesicoureteric reflux with different tissue-bulking substances in patients with end stage renal failure

PURPOSE

To evaluate the outcome of subureteral injections by using calcium hydroxyapatite (CaHa), dextranomer/hyaluronic acid copolymer (Dx/HA), and polydimethylsiloxane (PDS) in patients with end-stage renal failure (ESRF) who have vesicoureteral reflux (VUR).

PATIENTS AND METHODS

One hundred-one patients (166 renal units) with ESRF secondary to VUR were included in this retrospective study. The reflux was bilateral in 65 of the cases. CaHa, Dx/HA and PDS were used in 57, 26, and 18 patients, respectively. All patients were reviewed with regard to age, sex, reflux grade, type of injected materials, injectable agent volume, and outcome.

RESULTS

The reflux resolved completely in 30 patients (50/96 renal units, 52.1%), in 17 patients (27/44 renal units, 61.4%), and in 4 patients (5/26 renal units, 19.2%) with CaHa, Dx/HA, and PDS, respectively. Regression rates of reflux to grade I with these agents in the same order were 3.1% (2 patients, 3/96 renal units), 4.5% (1 patient, 2/44 renal units), and 11.5% (2 patients, 3/26 renal units). Thus, the overall success rate were noted as 55.2%, 65.9%, and 30.7%, respectively. There was no difference among these three injectables with regard to overall success rates (P = 0.062). No significant correlation with age, reflux grade, agent volume, and significant difference with sex were observed (P > 0.05).

CONCLUSIONS

In this group of patients, the success rate of the subureteral injection treatment does not appear to be affected by the type of the injectable agent. In addition, the cure rates were independent from the individual factors, reflux grades, and injected volumes.

[Vesico-ureteric reflux treatment by implant of polydimethylsiloxane (Macroplastique): Review of the literature]

PURPOSE

During the last 25years, endoscopic correction of vesicoureteral reflux (VUR) has become a well-recognized procedure. However, the nature of the bulking agent used has led to many controversies. The objective of this work was to perform a literature review on the use of polydimethylsiloxane (PDMS or Macroplastique) in VUR.

METHOD

A PubMed review of the literature since 1996 resulted in the selection of 24 studies of sufficient level of evidence to assess the efficacy and tolerance of Macroplastique in the VUR in adults and children.

RESULTS

The overall success rate at 1 year, 2 years and 9-years follow-up was respectively 86-93 %, 80-92 %, and 77-100 %, which confirms the maintenance of good results over time, notably in VUR grade III and above. The success rate was similar for primary and secondary VUR except for total duplicity. Predictive criterias of success were the surgeon's experience, the low grade of VUR, and the absence of previous injection. In comparison with other bulking agents, the higher viscosity and absence of shrinkage of the product increase its reliability. After more than 12years of use, no serious complication has been reported in the literature, reflecting the good tolerance of Macroplastique on the long term.

CONCLUSION

The studies published on the use of Macroplastique in VUR confirmed its efficacy, around 85 % of success for all grades, in children and adults as well. The interest of PDMS is linked to its higher viscosity promoting a better reliability and reproducibility of the technique and its non-resorbable nature providing a permanent result, especially valuable in high-grade VUR with anatomical anomaly of the vesicoureteral junction or in VUR secondary to permanent lower urinary tract dysfunction.

Long-term followup of dextranomer/hyaluronic acid injection for vesicoureteral reflux: late failure warrants continued followup

PURPOSE

Dextranomer/hyaluronic acid injection of ureteral orifices is a popular option in the treatment of vesicoureteral reflux, with success rates ranging from 69% to 89%. We found only 1 study that followed patients beyond the initial postoperative voiding cystourethrogram, which describes a 96% success rate at 2 to 5 years but defines success as "nondilating" reflux. We examined our dextranomer/hyaluronic acid series to evaluate the long-term (1-year) outcome in children who had resolution of reflux on initial postoperative voiding cystourethrography.

MATERIALS AND METHODS

We retrospectively reviewed our dextranomer/hyaluronic acid experience from February of 2002 to December of 2005. We determined initial success on early (6 to 12-week) postoperative voiding cystourethrogram. We then evaluated long-term success by obtaining a voiding cystourethrogram at 1 year postoperatively in patients who were initially cured of reflux. In addition, success rates between the first and second halves of our experience were evaluated to account for surgeon experience and modification of technique.

RESULTS

Our total success rate at initial voiding cystourethrogram was 73% (246 of 337 total ureters). The success rate in the first half of our experience was 65.9% (112 of 170 ureters) and in the second half was 80.2% (134 of 167). A total of 150 ureteral units with initial successful dextranomer/hyaluronic acid treatment were evaluated at 1 year by voiding cystourethrogram. Of these ureters 111 had continued resolution of vesicoureteral reflux, for a long-term success rate of 74%. Including initial postoperative failures, the complete 1-year total success rate was 46.1% (111 of 241 ureters).

CONCLUSIONS

Although the reflux resolution rates at initial postoperative voiding cystourethrogram approach those of open surgery, there is a significant failure rate at 1 year, which warrants long-term followup.

Learning from the learning curve: factors associated with successful endoscopic correction of vesicoureteral reflux using dextranomer/hyaluronic acid copolymer

PURPOSE

Conflicting reports exist regarding the parameters guiding successful correction of vesicoureteral reflux using dextranomer/hyaluronic acid copolymer. We performed logistic regression analysis to evaluate the effect of injected volume while adjusting for other factors potentially associated with success following dextranomer/hyaluronic acid copolymer injection.

MATERIALS AND METHODS

Between July 2003 and June 2006, 126 consecutive patients (34 boys and 92 girls) with a mean +/- SD age of 6.5 +/- 3.7 years with primary vesicoureteral reflux (196 refluxing ureters) underwent injection for febrile urinary tract infections. Success was defined as complete reflux resolution. Age, gender, laterality, preoperative vesicoureteral reflux grade, surgeon experience, dextranomer/hyaluronic acid copolymer volume, time to surgery from initial presentation and preoperative treatment for lower urinary tract symptoms were analyzed.

RESULTS

Vesicoureteral reflux grade was I to V in 7 (3.5%), 53 (27%), 91 (46.4%), 30 (15.3%) and 15 renal units (7.6%), respectively. The success rate after 1 injection was 50% by patient and 59.2% by ureter. Mean injected volume was 0.9 +/- 0.27 ml in those who had a successful injection vs 0.67 +/- 0.24 ml in those in whom injection failed (p <0.001). The success rate after 1 injection was 78.9% using 0.8 ml or greater dextranomer/hyaluronic acid copolymer compared to 31.7% with less than 0.8 ml. Multivariate analysis confirmed that higher dextranomer/hyaluronic acid copolymer volume (p = 0.001), lower preoperative grade (p = 0.013), surgeon experience (p = 0.025) and treatment for lower urinary tract symptoms (p = 0.009) were associated with successful correction of vesicoureteral reflux.

CONCLUSIONS

Our analysis strengthens the previously reported association of surgeon experience and vesicoureteral reflux grade with successful endoscopic vesicoureteral reflux correction. The data also revealed an association between injected volume and vesicoureteral reflux correction even while controlling for other variables, highlighting its importance as a true success modifier.

Utility of dextranomer/hyaluronic acid injection in setting of bladder and ureteral anomalies

OBJECTIVES

Previous studies have shown that the cure rates after dextranomer/hyaluronic acid (Dx/HA) injection can be decreased in patients with neurogenic bladder, previous ureteroneocystostomy, duplicated ureters, or periureteral diverticula. We attempted to determine whether these factors reduce the efficacy of Dx/HA injection compared with that in otherwise normal patients.

METHODS

All children with vesicoureteral reflux (VUR) undergoing Dx/HA injection from April 2002 to March 2006 at two institutions were eligible for this study. Multivariate logistic regression models were built to assess the effect of bladder/ureteral anomalies on the success of Dx/HA injection. We adjusted for previously described predictors of injection success, including VUR grade, sex, age, surgeon experience, and injection technique.

RESULTS

A total of 543 refluxing ureters (373 patients) were included, of which 145 (27%) had persistent VUR on postoperative voiding cystourethrography; 86 ureters (16%) had anatomic anomalies. On univariate analysis, the most important predictors of injection failure were increasing VUR grade, male sex, younger age, subureteral injection, ureteral duplication anomaly, increasing Dx/HA volume, and surgeon experience. On multivariate analysis, however, the only significant predictors of injection failure were increasing VUR grade, subureteral injection technique, and surgeon experience. No anatomic or functional abnormalities, considered individually or grouped, significantly affected the probability of injection failure.

CONCLUSIONS

In our experience, children with functional and anatomic bladder/ureteral anomalies were no more likely to have Dx/HA injection fail than were children with uncomplicated VUR. The most important predictors of Dx/HA success remained VUR grade, injection technique, and surgeon experience. Dx/HA injection in patients with complex bladders could be a reasonable therapeutic option.

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.

Are there predictive factors for the outcome of endoscopic treatment of grade III-V vesicoureteral reflux with dextranomer/hyaluronic acid in children?

Dextranomer/hyaluronic acid (Dx/HA) copolymer has been used widely for the treatment of vesicoureteral reflux (VUR) in children since 2001. However, the factors that influence the outcome of injection therapy with Dx/HA have remained unclear. In this study, we retrospectively evaluated the outcomes in 101 consecutive children to determine the cure and to identify the factors that can impact treatment outcomes of Dx/HA injection. Endoscopic treatment with Dx/HA was performed in 133 ureters, in 101 patients with grade III-V VUR. Of the patients, 68 (67.3%) were girls and the mean age was 6.5 years. Before and after the treatment, the presence and grades of VUR were determined by voiding cystourethrograms. The patients' age, gender, laterality, preoperative reflux grade, ureteral duplication, morphology of ureteral orifice, renal hypoplasia and experience with surgery were assessed as predictive factors related to the success rates of Dx/HA injection therapy. The cure rates were 54.8% after the first injection, 66.9% after the second and 73.6% after the third injection. Patients with a high grade (grade IV or V), duplicated system, golf hole-shaped orifice and renal hypoplasia had significantly lower cure rates (P<0.05). Experience with the technique also correlated with the positive outcome of the procedure. New contralateral vesicoureteral reflux developed in five (7.2%) patients with unilateral VUR, and all of them resolved spontaneously during the first year of followup. No treatment-related significant complication was encountered. Although, endoscopic treatment of VUR with Dx/HA provides a high rate of success in children with medium or high grade VUR, treatment failure may be seen in some patients. However, we showed that endoscopic treatment with Dx/HA was effective in selected patients with grade V VUR, and we emphasize the need for further large-scale studies to confirm our findings.