Multivariate analysis of factors predicting success with dextranomer/hyaluronic acid injection for vesicoureteral reflux

Primary vesicoureteral reflux

Primary vesicoureteral reflux (VUR) is one of the most common urological abnormalities in infants and children. The association of VUR, urinary tract infection (UTI) and renal parenchymal damage is well established. The most serious complications of VUR-associated reflux nephropathy are hypertension and proteinuria with chronic kidney disease. Over the past two decades, our understanding of the natural history of VUR has improved, which has helped to identify patients at increased risk of both VUR and VUR-associated renal injury. The main goals in the treatment of paediatric patients with VUR are the prevention of recurrent UTIs and minimizing the risk of renal scarring and long-term renal impairment. Currently, there are four options for managing primary VUR in infants and children: surveillance or intermittent treatment of UTIs with management of bladder and bowel dysfunction; continuous antibiotic prophylaxis; endoscopic subureteral injection of tissue-augmenting substances; and ureteral reimplantation via open, laparoscopic or robotic-assisted surgery. Current debates regarding key aspects of management include when to perform diagnostic imaging and how to best identify the paediatric patients that will benefit from continuous antibiotic prophylaxis or surgical intervention, including endoscopic injection therapy and minimally invasive ureteral reimplantation. Evolving technologies, such as artificial intelligence, have the potential to assist clinicians in the decision-making process and in the individualization of diagnostic imaging and treatment of infants and children with VUR in the future.

Predictors of reflux persistence after endoscopic dextranomer/hyaluronic Acid copolymer injection in pediatric patients with Vesicoureteral reflux: short-term results

This study aims to investigate the factors effective in predicting the persistence of reflux after the first subureteric transurethral injection (STING) of dextranomer/hyaluronic acid copolymer in pediatric patients with vesicoureteral reflux. The data of patients without a previous history of surgery to treat vesicoureteral reflux and who underwent STING for the first time between September 2011 and November 2020 were investigated retrospectively. After considering exclusion criteria, of 199 patients, 127 patients and 180 renal units were suitable for inclusion. A renal unit-based evaluation was made. Age < 61 months (univariate: p = 0.001, multivariate: p = 0.015, HR: 2.352 (1.181-4.686), OR (95% CI)), moderate reflux level (grade 3) (univariate: p < 0.001, multivariate: p = 0.019, HR: 2.703 (1.177-6.209), OR (95% CI)), DRF (differential renal function) < 45 (univariate: p = 0.020, multivariate: p = 0.047, HR: 1.992 (1.009-3.935), OR (95% CI)), and UDR (ureteral diameter ratio) > 0.15 (univariate: p < 0.001, multivariate: p = 0.005, HR: 2.786 (1.368-5.672), OR (95% CI)) were found predictors of reflux persistence after STING surgery both univariate and multivariate analysis. High reflux level (grade 4-5) was statistically significant in univariate analysis (p < 0.001) but not statistically significant in multivariate analysis (p = 0.215). In our study, UDR and DRF were found to be factors affecting reflux persistence. UDR and DRF should be considered in order to predict reflux resolution in patients who will undergo STING.

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.

Modified unilateral periureteral injection technique in the treatment of patients with high-grade vesicoureteral reflux: A study of primary findings

Objective

Although endoscopic treatment has been used by many pediatric urologists for the treatment of vesicoureteral reflux (VUR), it has no considerable success in high-grade VUR. We aimed to describe the primary outcomes of unilateral periureteral injection technique (PIT), as well as bilateral PIT in high-grade VUR.

Methods

In this prospective study, we examined 92 ureters in 45 boys and 40 girls from February 2010 to May 2018. Bilateral PIT and unilateral PIT were applied in 67 and 25 refluxing units, respectively. In the unilateral PIT, the subureteral injection site was only at the 5- or 7-o'clock position. However, in the bilateral PIT, the subureteral injection sites were at 5- and 7-o'clock position. Pre- and post-operative reflux grades were evaluated by voiding cystourethrography 6 months after surgery.

Results

Seven patients had bilateral reflux. Overall, 75 (81.5%) ureters showed Grade IV VUR, while 17 (18.5%) had primary Grade V VUR. The mean age of the subjects was 39.2 months. In unilateral PIT ureters, VUR was resolved in 23 (92.0%) refluxing units. It was downgraded to Grade III in one ureter (4.0%) and to Grade II in another ureter (4.0%). In addition, in bilateral PIT cases, VUR was resolved in 60 (89.6%) ureters; it downgraded to Grades II and III in 3 (4.5%) and 4 (6.0%) refluxing units, respectively.

Conclusion

Unilateral PIT can be highly effective in the treatment of selected ureters of high-grade VUR. However, further studies are needed to confirm our results.

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.

Treatment of Vesicoureteral Reflux Detected After Renal Transplant in Pediatric Patients: A Single-Center Experience

OBJECTIVE

In children who undergo renal transplant, vesicoureteral reflux on the transplanted kidney is a serious complication that may result in organ loss. In this study, we aimed to evaluate the results of endoscopic and open surgical techniques in the treatment of patients with recurrent urinary tract infections and vesicoureteral reflux after renal transplant.

MATERIAL AND METHODS

The files of pediatric patients who underwent renal transplant in our hospital between January 2016 and January 2019 were evaluated retrospectively. In this single-center analysis, we investigated the incidence of vesicoureteral reflux in the kidney transplant recipients and the results of various approaches to treat it.

RESULTS

Eighty pediatric patients underwent renal transplant between January 2016 and January 2019. Fourteen of those patients (17.5%, 7 female and 7 male) were diagnosed with vesicoureteral reflux in the postoperative period. Twelve of 14 patients received endoscopic injections as the first treatment. Clinical or radiological success was achieved in 5 patients (5 of 15 injection treatments, 33%); in 4 patients (4/12, 33.3%) success was after the first endoscopic injection treatment, and in 1 patient (1/3, 33.3%) success was after the second injection. Meanwhile, clinical or radiological success was achieved in 6 of 7 patients who underwent redo ureteroneocystostomy (6/7, 85.7%).

CONCLUSION

Although symptomatic vesicoureteral reflux after renal transplant is rare in pediatric patients, it is an important cause of morbidity as it requires recurrent surgical procedures. Although endoscopic treatment is safe and minimally invasive, the success rate is lower than expected, and redo of ureteral reimplant may be required in most cases.

Antireflux endoscopic injection therapy in post-pubertal patients via techniques adopted for the dilated ureteral orifice: a retrospective single-center study

BACKGROUND

To investigate the efficacy and safety of endoscopic injection therapy for vesicoureteral reflux in post-pubertal patients with dilated ureteral orifice via modified hydrodistension implantation techniques.

METHODS

We retrospectively reviewed medical records including operational procedure and clinical course of all consecutive patients over 12 years old with a history of injection therapy. Endoscopic injection of dextranomer/hyaluronic acid copolymer was performed under hydrodistension implantation technique with some modifications in order to inject through dilated ureteral orifice align with the intramural ureter. Technical selections were done according to hydrodistension grade of the ureteral orifice. Voiding cystourethrography was evaluated at 3 months postoperatively. Hydronephrosis was evaluated using ultrasonography preoperatively until 6 months postoperatively.

RESULTS

From 2016 to 2019, 12 patients (all female, 16 ureteral units; median age 32 [range 15-61] years) underwent endoscopic injection therapy at one of our institutions. We have identified grade II vesicoureteral reflux in 5 ureters, grade III in 8, and grade IV in 3 ureters. Grade 3 ureteral-orifice dilation were presented in 12 ureters (75%), grade 2 in 3 and grade 1 in 1 ureter in the present cases. Postoperatively, vesicoureteral reflux was diminished to grade 0 in 12 ureteral units (75%), decreased to grade I in 3 (9%), and remained grade III in 1 (6%). Three patients reported dull flank pain for several days postoperatively and there was 1 case of acute pyelonephritis. Temporary hydronephrosis was confirmed in 3 ureteral units (19%) at 1 month postoperatively. Median follow-up duration was 23 (range 13-63) months long. Although, 3 patients were experienced f-UTI 1-2 times, repeated VCUG showed no VUR recurrence.

CONCLUSIONS

According to hydrodistension grade of the ureteral orifice, endoscopic injection therapy via modified hydrodistension implantation technique is an effective and safe treatment for vesicoureteral reflux in post-pubertal female patients with dilated ureteral orifice. While ureteral deformities or a history of anti-reflux surgery may increase the risks, these can be managed with appropriate methods that ensure sufficient mound appearance and height.

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.

Do Volume of Injection and Learning Curve Influence the Results of Endoscopic Correction of Vesicoureteric Reflux Using Dextranomer/Hyaluronic Acid? A Single Surgeon Experience

Background: Available reports regarding the technical factors for successful endoscopic treatment (ET) of vesicoureteric reflux (VUR) using dextranomer/hyaluronic acid copolymer are inconclusive. We studied single-surgeon data to evaluate the association of injected volume and surgeon experience with success after ET for VUR. Materials and Methods: Fifty-eight children (87 ureters) with grades 2-4 primary VUR were included. Success was defined as complete resolution of reflux on follow-up imaging. Volume of injection between success and failed groups was analyzed; volume of injection was further studied using receiver operating characteristic curve (ROC) analysis. Patients were then divided into two groups: group 1 (early experience) and group 2 (later experience). Both groups were compared for age, grade of reflux, volume of injection, and success. Results: Overall success of one injection was 76%. The mean volume of injection was significantly larger in successful ureters than failed ureters (P = .008). On ROC analysis, the volume of 0.75 mL (area under curve 0.747, 95% confidence interval 0.60-0.89) had a good discriminative ability to predict success of the injection procedure. Furthermore, a volume cutoff of 0.8 mL demonstrated significant influence on success (success 14/25 ureters for <0.8 mL and 36/42 ureters for 0.8 mL or more volume of injection, P = .0097), whereas no difference in success was observed with a cutoff volume of 0.9 mL (P = .2480). When the patients were divided into two groups based on surgeon experience, group 2 demonstrated better success than group 1 (84% versus 65%, P = .04). Both groups were comparable for age (P = .09), grade of reflux (0.46) and the median volume of injection was similar (0.8 mL) in both the groups. Conclusions: We found that a minimal volume of 0.75 mL dextranomer/hyaluronic acid injection may be required to achieve success of ET in moderate grade primary VUR. Success also improved with increasing surgeon experience.

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.

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.

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.

The Swedish infant high-grade reflux trial: Study presentation and vesicoureteral reflux outcome

INTRODUCTION

High-grade vesicoureteral reflux (VUR) in infants is associated with congenital renal abnormalities, recurrent UTI, and bladder dysfunction. Endoscopic treatment (ET) is a well-established method in children with low to moderate reflux grades, but there is a lack of randomised controlled trials regarding the use of ET versus continuous antibiotic prophylaxis in infants with high-grade VUR.

OBJECTIVE

This study aimed to determine whether high-grade VUR in infants can be treated with endoscopic injection and whether ET is superior to antibiotic prophylaxis in the treatment of VUR.

MATERIALS AND METHODS

This prospective, randomised, controlled, multicentre, 1-year follow-up trial comprised 77 infants (55 boys, 22 girls) <8 months of age with VUR grade 4-5 (n = 30/n = 47). Of the infants, 52 (68%) had bilateral VUR. Thirty-nine were randomised to antibiotic prophylaxis and 38 to ET (with prophylaxis until resolution). Voiding cystourethrogram, ultrasound, renal scintigraphy, and free voiding observation were performed at study entry and after 1 year to evaluate VUR grade, and renal and bladder function.

RESULTS

VUR grade ≤2 was seen in 22 (59%) infants in the endoscopy group and eight (21%) in the prophylaxis group at follow-up (p = 0.0014). The success rate in the endoscopy group was 100% in unilateral grade 4, falling to 31% in bilateral grade 5 (p = 0.0094). Correspondingly, the results in the prophylaxis group were 40% in grade 4 down to 0% in bilateral grade 5 (p = 0.037) (Table). Logistic regression analyses identified ET, VUR grade 4, unilaterality, and low residual urine at baseline as positive predictors of VUR down-grading to ≤2 (area under ROC curve 0.88). In four patients with reflux resolution after one injection, dilating reflux recurred at the 1-year follow-up. One patient had a UTI possibly related to ET. In our material four patients required re-implantation, of whom one was obstructive after injection.

DISCUSSION

The opportunity to offer even small infants with high-grade VUR an alternative, minimally invasive treatment option is a great advance in paediatric urology. In this high-risk group, bilateral VUR grade 5 stands out with its poor bladder function and low chance of resolution. The recurrence rate of dilating VUR after successful ET is consistent with previous studies. The limitations are the relatively small number of patients and the short follow-up.

CONCLUSION

High-grade VUR in infants can be treated with injection therapy and the resolution rate is higher than that of prophylaxis treatment. The complication rate is low and VUR grade 4, unilaterality, and low residual urine are favourable for the resolution and down-grading of VUR.

STING versus HIT technique of endoscopic treatment for vesicoureteral reflux: A systematic review and meta-analysis

AIM

Our study aimed to compare the efficacy of two endoscopic techniques used for the correction of vesicoureteral reflux (VUR): subureteral transurethral injection (STING) and hydrodistension implantation technique (HIT).

METHODS

A systematic review was conducted using MEDLINE, Google scholar, and Cochrane databases from 1984 to 2015. Meta-analysis of the selected studies was performed to compare the extent of reflux resolution following both techniques.

RESULTS

Six observational studies met the inclusion criteria for content. These comprised 632 ureters treated by STING and 895 ureters treated by HIT procedure. All included studies utilized dextranomer/hyaluronic acid (Deflux) as the bulking agent. The overall resolution of VUR was significantly higher in HIT (82.5%) compared to STING (71.4%) [pooled odds ratio (OR)=0.54; 95% confidence interval (CI) 0.42-0.69; P<0.0001; I²=8%]. A subgroup analysis showed that HIT had better outcomes than STING for both lower grade (I-III) [OR=0.43; 95% CI 0.23-0.82; P=0.01; I²=0%] and high-grade VUR (IV-V) [OR=0.43; 95% CI 0.20-0.91; P=0.03; I²=0%]. However, there was no statistical difference in the requirement of additional injections between STING and HIT groups.

CONCLUSION

HIT is superior to STING technique for resolution of VUR after Deflux injection. However, more randomized trials with longer follow-up are necessary to demonstrate the benefit of HIT compared to STING procedure.

LEVEL OF EVIDENCE

Retrospective comparative studies - level III.

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.

Contemporary Management of Vesicoureteral Reflux

The past 30 years have seen broad changes in the diagnosis and management of vesicoureteral reflux (VUR). Recently, a clinical debate has generated an open discussion in academic circles. New evidence has shifted treatment patterns away from widespread surgical management and recently brought into question some pharmacologic treatments. VUR is usually not hazardous by itself but is a significant risk factor for urinary tract infection (UTI) and less commonly, renal scarring and insufficiency. Given the costs and morbidity of UTI as well as the potential for significant renal injury, our approach remains conservative. Careful follow-up, parental education about pathophysiology and management of VUR and UTI, and management of bowel and bladder dysfunction (BBD) when present, are the foundation of treatment. Additionally, though we recognize the limitation of continuous antibiotic prophylaxis (CAP), we believe the benefits outweigh the risks and costs for many patients. Careful observation can be considered in patients with a single medical home, parental understanding of what UTI signs and symptoms are, low grade VUR, no history of complicated UTIs and close follow-up. Surgical management remains a relevant option for select patients who fail conservative measures with breakthrough UTIs or failure to resolve. Minimally invasive surgical options are available with acceptable outcomes though open ureteroneocystostomy still carries the highest success rate.

Is a secondary procedure necessary in every case of failed endoscopic treatment for vesicoureteral reflux?

Purpose

Endoscopic treatment (ET) has become a widely accepted procedure for treating vesicoureteral reflux (VUR). However, patients followed up after ET over long periods have reported persistent or recurrent VUR. We evaluated the natural course of failed ET in patients who required further treatments to help physicians in making decisions on the treatment of VUR.

Materials and Methods

We retrospectively reviewed the medical records of patients who were diagnosed with VUR and underwent ET from January 2006 to December 2009. A total of 165 patients with 260 ureters underwent ET. We compared the parameters of the patients according to ET success or failure and evaluated the natural course of the patients after ET failure.

Results

Mean VUR grade and positive photon defect were higher in the failed ET group than in the successful ET group. Six months after the operation, persistent or recurrent VUR was observed in 76 ureters (29.2%), and by 16.3 months after the operation, VUR resolution was observed in 18 ureters (23.7%). Twenty-five ureters (32.9%) without complications were observed conservatively. Involuntary detrusor contraction was found in 1 of 9 (11.1%) among the secondary ET success group, whereas in the secondary ET failure group, 4 of 6 (66.7%) had accompanying involuntary detrusor contraction.

Conclusions

Patients in whom ET fails can be observed for spontaneous resolution of VUR unless they have febrile urinary tract infection or decreased renal function. Urodynamic study may be helpful in deciding whether a secondary procedure after ET failure is necessary.

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 for vesicoureteral reflux: how important is technique?

PURPOSE

Endoscopic dextranomer/hyaluronic acid (Dx/HA) injection by subureteric transurethral injection (STING) or hydrodistention implantation technique (HIT) for treatment of vesicoureteral reflux (VUR) has variable results with HIT reporting better outcomes. We determined outcomes with each technique comparing reflux resolution rates and evaluating predictors of treatment success and failure.

METHODS

Univariate and multivariate analysis compared 163 patients (246 ureters) who underwent a single endoscopic Dx/HA injection from December 2001 to April 2010. Data on pre, peri, and post-operative variables were prospectively collected. Resolution was defined as no reflux on voiding cystourethrogram (VCUG) at 3 month follow up. Calculated ellipsoid volume (CEV) of Dx/HA mounds was defined as (4/3π(height/2) × (length/2) × (width/2)) based on post-operative ultrasound dimensions.

RESULTS

Ureter resolution was 79.75% and 80.84% for STING and HIT, respectively (p = 0.86). Patient resolution was 70.0% and 74.3% for STING and HIT, respectively (p = 0.57). Multivariate ureter analysis revealed lower pre-operative grade (p = 0.004) and injected Dx/HA volume 0.80-1.00 mL (p = 0.039) as predictors of success. CEV <0.20 mL (p = 0.002) and CEV/injected-volume <25% (p = 0.006) were predictors of failure. Volcano morphology (p = 0.004) and lower pre-op grade (p = 0.015) were predictors of success for STING and HIT, respectively.

CONCLUSIONS

We found no differences in ureter or patient resolution between endoscopic Dx/HA injection techniques STING or HIT. Lower pre-operative grade and moderated Dx/HA volume were predictors of success regardless of technique.

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.

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.

Intermediate to long-term follow-up indicates low risk of recurrence after Double HIT endoscopic treatment for primary vesico-ureteral reflux

PURPOSE

Follow-up of patients undergoing dextranomer/hyaluronic acid injection for vesico-ureteral reflux (VUR) is controversial. The purpose of our study was to test the hypothesis that patients undergoing the double hydrodistention-implantation technique (Double HIT) have a higher clinical and radiographic success rate.

MATERIALS AND METHODS

Patients undergoing Double HIT endoscopic injection for VUR were prospectively identified. Patients underwent an ultrasound at 6 weeks to assess the implants, and, if visible, prophylactic antibiotics were discontinued and patients were scheduled for a 1-year voiding cystourethrogram (VCUG). Radiographic success was defined as a negative VCUG and clinical success as no febrile urinary tract infections at 1 year.

RESULTS

A total of 54 patients underwent endoscopic injection for VUR. Twenty-five (51%) were compliant with the 1 year follow-up; 18 non-compliant patients were contacted and their clinical status assessed. Thirty patients eventually completed the 1-year VCUG at a mean of 12.2 months (range 10-20). Among the 60% of patients with 1-year radiographic follow-up, 2 had persistent VUR for a radiologic success rate of 93%. All radiographic failures were infection-free. Of the 80% (43/54) of patients with available clinical data, 3 (7%) had afebrile UTI for a clinical success rate of 93%.

CONCLUSIONS

The Double HIT leads to a 93% clinical and 93% radiographic intermediate/long-term success rate. With this technique, better outcomes were achieved with fewer recurrences than previously reported. These favorable results challenge the need for postoperative VCUG in asymptomatic patients after the Double HIT.

Surgical management of vesicoureteral reflux in children

Vesicoureteral reflux (VUR) is the most common uropathy affecting children. Compared to children without VUR, those with VUR have a higher rate of pyelonephritis and renal scarring following urinary tract infection (UTI). Options for treatment include observation with or without antibiotic prophylaxis and surgical repair. Surgical intervention may be necessary in patients with persistent reflux, renal scarring, and recurrent or breakthrough febrile UTI. Both open and endoscopic approaches to reflux correction are successful and reduce the occurrence of febrile UTI. Estimated success rates of open and endoscopic reflux correction are 98.1% (95% CI 95.1, 99.1) and 83.0% (95% CI 69.1, 91.4), respectively. Factors that affect the success of endoscopic injection include pre-operative reflux grade and presence of functional or anatomic bladder abnormalities including voiding dysfunction and duplicated collecting systems. Few studies have evaluated the long-term outcomes of endoscopic injection, and with variable results. In patients treated endoscopically, recurrent febrile UTI occurred in 0-21%, new renal damage in 9-12%, and recurrent reflux in 17-47.6% of treated ureters with at least 1 year follow-up. These studies highlight the need for standardized outcome reporting and longer follow-up after endoscopic treatment.

Does compliance status predict clinical status in patients undergoing endoscopic management of vesico-ureteral reflux?

OBJECTIVE

Previous studies of endoscopic management of vesico-ureteral reflux (VUR) have had non-compliance rates around 50%. We examined success rates of patients non-compliant with a delayed follow up protocol after endoscopic injection for VUR.

MATERIALS AND METHODS

Patients undergoing Double HIT, dextranomer/hyaluronic acid copolymer endoscopic injection for VUR were enrolled in a 1-year, delayed voiding cysto-urethrogram (VCUG) study. All patients non-compliant with the VCUG were contacted and information on their clinical status was collected. Non-compliant patients were re-scheduled for a VCUG.

RESULTS

49/54 (91%) patients underwent endoscopic injection for VUR and completed the 6-week ultrasound. At 1-year 49% (24/49) were non-compliant with a VCUG; 75% (18/24) were contacted and provided clinical information. All but one patient agreed to the VCUG. Patients compliant with the 1-year VCUG showed 96% (24/25) clinical and 92% (23/25) radiologic success rates. Non-compliant patients had an 89% (16/18) clinical success rate; 5 (21%) non-compliant patients underwent VCUGs with a 100% success rate.

CONCLUSIONS

Long-term compliance remains an issue for patients treated endoscopically for VUR, but compliance does not predict clinical status as both groups have favorable clinical outcomes. The repeat VCUG is a barrier to long-term follow up as only 21% of patients underwent the study.

Endoscopic vesicoureteral reflux correction in transplanted kidneys: does injection technique matter?

AIM AND BACKGROUND

Posttransplant vesicoureteral reflux (VUR) is a common urologic complication after renal transplantation, although its management is controversial. The treatment of choice is open surgical revision ureteral reimplantation with significant morbidity. Recently, endoscopic correction by using nonanimal dextranomer/hyaluronic acid copolymer (NA Dx/HA) injection has been reported to be effective in the treatment of VUR of transplanted kidneys. Herein, we present our 3-year endoscopic correction results in transplanted kidneys where we used two different injection techniques, subureteral and intraureteral.

MATERIALS AND METHODS

We retrospectively reviewed all patients who underwent endoscopic VUR correction of posttransplant VUR by NA Dx/HA injection between July 2005 and March 2009. We excluded patients with underlying urologic abnormalities.

RESULTS

A total of 26 patients (14 women and 12 men) with a mean age of 32.2 years (range: 15–55) were studied. The VUR was also graded as nondilating reflux in 10 (grade I–II) and dilating reflux in 16 (grade III–IV). Seventeen ureters (5 nondilating and 12 dilating VUR) were injected NA Dx/HA intraureterally, and 9 ureters (5 nondilating and 4 dilating VUR) were injected NA Dx/HA subureterally. Overall success rate was 53.8% (14 out of 26). Intraureteral injection technique was successful in nine cases (52.9%), and subureteral injection technique was successful in five cases (55.5%). In nondilating VUR, injection corrected 90% (9 out of 10) of posttransplant patients, whereas in dilating VUR group injection corrected only 31.25% (5 out of 16). We found no statistical significance of injection technique on the success rate.

CONCLUSIONS

Endoscopic correction by using NA Dx/HA with any injection technique seems to be a plausible alternative to correction of refluxing posttransplant ureters, particularly in nondilating VUR.

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.

The clinical utility and safety of the endoscopic treatment of vesicoureteral reflux in patients with duplex ureters

OBJECTIVE

A systemic review of published literature on the use of bulking agents in the treatment of vesicoureteral reflux (VUR) in patients with duplex systems was performed in order to evaluate the diagnostic challenges; determine success rates, and compare with use in single systems; and evaluate safety, in particular of Deflux.

METHODS

A PubMed/Medline search was conducted for index articles discussing duplex ureters published in 1963-2007. All types of publications were included. A multiple linear regression analysis was performed.

RESULTS

Overall, 28 different treatment arms originating in 17 separate studies (19 publications) satisfied the inclusion criteria for linear regression efficacy analysis. Data were available on 2879 patients: 2400 with single and 479 with duplex systems. Ten publications provided information on the frequency of failure to diagnose duplex systems using specific techniques. An overall 18% failure rate to detect duplex systems was reported for combined techniques. For patients in whom favorable anatomic location of ureters allowed successful endoscopic injection of a bulking agent, correction of VUR was achieved in 53-100% of cases. A univariant analysis showed no difference in success rate between single and duplex systems with the use of Deflux, or other bulking agent. The predicted probability of success in a single system was 68% and in a duplex system 64%.

CONCLUSIONS

There is significant potential for failing to detect duplex systems prior to preparing an individual for either open or endoscopic treatment. From the studies available, endoscopic injection of bulking agents is highly successful in correcting mild-to-moderate VUR in duplex systems, with no reports of serious or clinically significant adverse effects. At a minimum, duplex systems would not seem to be a contraindication to the use of Deflux or any other bulking agent.

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.

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.

Intra-orifice versus hydrodistention implantation technique in dextranomer/hyaluronic acid injection for vesicoureteral reflux

PURPOSE

Original implantation procedures used dextranomer/hyaluronic acid to create a volcano-like mound at the orifice. Subsequently the hydrodistention implantation technique was described to coapt the intramural ureteral wall with less emphasis on achieving a mound at the orifice and it was reported to be associated with improved outcomes. We compared the results of intra-orifice injection to establish a mound vs the hydrodistention implantation technique.

MATERIALS AND METHODS

Univariate and multivariate logistic regression analysis was used to compare results in 96 ureters undergoing intra-orifice injection vs 52 undergoing the hydrodistention implantation technique. We evaluated patient gender and age, reflux grade, injection technique, injected volume and the number of injection sites.

RESULTS

Successful reflux resolution was achieved in 124 ureters (84%) with a single implantation, including 83 (86.5%) with intra-orifice injection and 41 (79%) with HIT (p = 0.23). Mean injected volume was significantly increased for the hydrodistention implantation technique vs intra-orifice injection (0.68 vs 0.51 cc, p = 0.002). Univariate analysis showed that female gender, older age, reflux grade and number of injection sites were associated with success. On multivariate analysis only reflux grade remained significant.

CONCLUSIONS

Despite using an increased volume of dextranomer/hyaluronic acid to coapt the intramural ureter and orifice, the hydrodistention implantation technique did not improve results over those of intra-orifice injection with a lesser implant volume.

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.

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.

Treatment of vesicoureteral reflux after puberty

Vesicoureteral reflux is uncommonly diagnosed and treated after puberty. The natural history of uncorrected VUR after puberty is not documented. Postpubertal patients with recurrent pyelonephritis and VUR should be considered for treatment. Ureteral reimplantation, endoscopic injections, and laparoscopic or robotic ureteral reimplantation may be utilized. Endoscopic injection is an appealing option for these patients. The role of laparoscopic or robotic ureteral reimplantation in these patients is evolving.

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.