Acute and delayed vesicoureteral obstruction after endoscopic treatment of primary vesicoureteral reflux with dextranomer/hyaluronic acid copolymer: why and how to manage

Advancements in Surgical Management of Megaureters

PURPOSE OF REVIEW

To review and describe the recent evolution of surgery for the various types of pediatric megaureter.

RECENT FINDINGS

Megaureter management first relies on determining the underlying cause, whether by obstruction, reflux, or a combination, and then setting appropriate surgical indications because many cases do not require surgery as shown by observation studies. Endoscopic balloon dilation has been on the rise as a major treatment option for obstructive megaureter, while refluxing megaureters can also be treated by laparoscopic and robotic techniques, whether extravesically or transvesicoscopically. During ureteral reimplantation, tapering is sometimes necessary to address the enlarged ureter, but there are also considerations for not tapering or for tapering alternatives. Endoscopic and minimally invasive surgeries for megaureter have been the predominant focus of recent megaureter literature. These techniques still need collaborative prospective studies to better define which surgeries are best for patients needing megaureter interventions.

Vantris vs. deflux for treatment of paediatric vesicoureteral reflux: Efficacy and obstruction risk

INTRODUCTION

The aim was to compare the efficacy of polyacrylate polyalcohol copolymer (PPC) injections and dextranomer/hyaluronic acid (Dx/Ha) injections for the endoscopic treatment of vesicoureteral reflux in children.

MATERIAL

This retrospective cohort study included 189 young patients who had endoscopic treatment for vesicoureteral reflux from January 2012 to December 2019 in our center. Among them, 101 had PCC injections and 88 had Dx/Ha injections. Indications for treatment were vesicoureteral reflux with breakthrough urinary tract infection or vesicoureteral reflux with renal scarring on dimercaptosuccinic acid (DMSA) renal scan. Endoscopic injection was performed under the ureteral meatus. Early complications, recurrence of febrile urinary tract infection and vesicoureteral reflux after endoscopic injection, ureteral obstruction and reintervention were evaluated and compared between groups.

RESULTS

Endoscopic treatment was successful in 90.1% of patients who had PPC injection and in 82% of patients who had Dx/Ha injection. Four patients presented a chronic ureteral obstruction after PPC injection, one with a complete loss of function of the dilated kidney. One patient in the Dx/Ha group presented a postoperative ureteral dilatation after 2 injections.

CONCLUSION

Despite a similar success rate after PPC and Dx/Ha injections for endoscopic treatment of VUR, there may be a greater risk of postoperative ureteral obstruction after PPC injections. The benefit of using PPC to prevent febrile UTI and renal scarring in children with low-grade VUR does not seem to outweigh the risk of chronic ureteral obstruction.

LEVEL OF EVIDENCE: 4

Successful rescue pneumovesicoscopic surgery for post-Deflux® vesicoureteral junction obstruction

BACKGROUND

Vesicoureteral junction (VUJ) obstruction after Deflux® subureteral injection for vesicoureteral reflux (VUR) is rare and minimally invasive management has not been reported. This work investigated the patients who underwent Deflux® injection for VUR and identified those with subsequent VUJ obstruction.

METHODS

Medical records of matched patients from October 2003 to March 2022 were reviewed, and parameters were retrospectively studied. All patients underwent Deflux® injection. The injection was performed under general anesthesia using the same manner. For patients complicated with VUJ obstruction, the symptoms, signs, management, images, renal ultrasounds, Tc-99m dimercaptosuccinic acid renal scintigraphy, histology of VUJ region, and outcomes were documented and reported. VUJ stenosis was diagnosed by performing renal ultrasound and magnetic resonance imaging.

RESULTS

Totally 407 patients (554 ureterorenal units) received Dx/HA injections for VUR. VUJ obstruction was found in three patients (four ureterorenal units). Originally, three were grade V VUR, and one was grade IV. The repeated injection was not a risk factor for VUJ obstruction. The overall incidence of VUJ obstruction post-Dx/HA injection was 0.7% by ureter. The incidences were 0%, 0.75%, and 2.25% for grade I-III, IV, and V VUR, respectively. After the initial conversion case of pneumovesicoscopic ureteral reimplantation, the procedure was performed smoothly and successfully in the two following cases.

CONCLUSIONS

Pneumovesicoscopic ureteral reimplantation offers an alternative for VUJ obstruction following Dx/HA injection for VUR. Fibrosis and foreign-body reaction may influence the feasibility. High-grade VUR and young age of injection were related to VUJ obstruction.

Vesicoureteral Reflux: Current Care Trends and Future Possibilities

Although investigations over the past 2 decades have improved our understanding of the natural history of vesicoureteral reflux (VUR) and helped identify those at higher risk of both VUR itself as well as its potential severe sequelae, debate exists regarding key aspects of care, including when to perform diagnostic imaging and which patients benefit from continuous antibiotic prophylaxis. Artificial intelligence and machine learning have the potential to distill large volumes of granular data into practical tools that clinicians can use to guide diagnosis and management decisions. Surgical treatment, when indicated, remains highly effective and is associated with low morbidity.

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

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

Fluoroscopy-guided percutaneous antegrade approach for ureteral stent placement in children: a single-center experience

BACKGROUND

Although there are many studies on percutaneous nephrostomy in urinary obstruction management in pediatric patients, there is a limited number of studies on percutaneous antegrade ureteral stenting (PAUS) on this issue.

PURPOSE

To evaluate the results of fluoroscopy-guided percutaneous antegrade approach for ureteral stent placement through the nephrostomy route in children.

MATERIAL AND METHODS

Between October 2005 and June 2019, the medical records of children who underwent PAUS through the nephrostomy route were reviewed retrospectively. Demographic data of the patients, technical and clinical success rates, technical details, and complications of the procedure were recorded. Patients were divided and evaluated into groups according to etiology. Categorical data were analyzed by using the Pearson chi-square test.

RESULTS

In total, 31 patients (19 boys, 12 girls; age range = 2 months-18 years; mean age = 7.4 ± 6.01 years) and 42 procedures were included in the study. The most common underlying diseases were ureteropelvic junction obstruction (16 stents, 38.1%) and vesicoureteral reflux (13 stents, 31%). The technical and clinical success rates were 97.6% and 90%, respectively. Clinical failure (10%) was not related to gender, underlying diseases, and stent size (P > 0.05). Mean stent dwelling time was 96.43 ± 58.1 days. Complications were urinary tract infection (two procedures), stent migration (two procedures), early occlusion (one procedure), and contrast material leak after balloon dilation (one procedure). The complication rate was 14.6%. No procedure-related death was observed.

CONCLUSION

PAUS through the nephrostomy route in children is an effective and reliable method when surgical treatment is not feasible.

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.

High-pressure balloon dilatation in children: our results in 30 patients with POM and the implications of the cystoscopic evaluation

Primary Obstructive Megaureter (POM) is a common cause of hydronephrosis in children with spontaneous resolution in most cases. High-Pressure Balloon Dilatation (HPBD) has been proposed as a minimally invasive procedure for POM correction in selected patients. The aim of the paper is to review our experience with HPBD in patients with POM. We performed a retrospective study in a single Centre collecting data on patients' demographics, diagnostic modalities, surgical details, results and follow-up. In particular, the endoscopic aspect of the orifice permitted the identification of 3 patterns: adynamic ureteral segment, stenotic ureteric ring and pseudoureterocelic orifice. We performed HPBD in 30 patients over 6 years. We had 23 patients with adynamic distal ureteral segment (type 1), 4 with stenotic ring (type 2) and 3 with ureterocelic orifice (type 3). In 3 patients (10%) the guidewire did not easily pass into the ureter requiring ureteral stenting or papillotomy. Post-operative course was uneventful. Five patients (3 pseudoureterocelic) required open surgery during follow-up. HPBD for the treatment of POM is a safe and feasible procedure and it can be a definitive treatment of POM. Complications are mainly due to double J stent and none of our patients had symptoms related to vescico-ureteral reflux. The aspect of the orifice, identified during cystoscopy, seems to correlate with the efficacy of the dilatation: type 1 and 2 are associated with good and excellent results respectively; type 3 do not permit dilatation in almost all cases requiring papillotomy. HPBD can be performed in selected patients of all paediatric ages as first therapeutic line. The presence of a pseudoureterocelic orifice or long stenosis might interfere with the ureteral stenting and seems associated with worse outcomes.

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

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

What are the predictive factors leading to ureteral obstruction following endoscopic correction of VUR in the pediatric population?

BACKGROUND

It is extremely important to not only address the short-term success following endoscopic correction of vesicoureteral reflux (VUR) but also the long-term efficacy and safety of the tissue augmenting substance utilized for endoscopic correction.

OBJECTIVE

This study retrospectively evaluated all cases of ureterovesical junction (UVJ) obstruction following endoscopic treatment of VUR over the last 5 years utilizing two tissue augmenting substances, with special emphasis on the safety of Vantris^®, and performed clinical and histological review of these patients.

METHODS

The study population comprised 2495 patients who underwent endoscopic correction of VUR utilizing Deflux^® (1790) and Vantris^® (705). Tissue sections were stained with hematoxylin & eosin and trichrome, and examined under a light microscope. Nine primary obstructive megaureters after ureteral re-implantation served as controls.

RESULTS

Nine (0.5%) children (three female and six male) in the Deflux group and nine (1.3%) (five females and four males) in the Vantris group developed UVJ obstruction and required ureteral re-implantation. Obstruction developed during the period ranging 2-49 months (average 16 months) following endoscopic correction. The primary reflux grade was III in seven, IV in six, and V in six children. The mean volume of the injected material in all obstructed patients was 1.2 ± 0.6 cc (mean ± SD). Histopathological analysis revealed a pseudocapsule composed of fibrous tissue and foreign-body giant cells surrounding the Vantris implant in all patients. The distal part of the ureters demonstrated significant ureteral dilatation without ureteral fibrosis. In all patients, additional biopsies from the muscularis propria adjacent to the injection site were examined and showed no significant abnormalities. There was an increased collagen deposition in the juxtavesical segment of the obstructive ureters following Deflux and Vantris injections, and of primary obstructive megaureter. No significant difference was found in the tissue response between Deflux and Vantris patients and controls. Statistical analysis of the nonhomogeneous population demonstrated higher obstruction rates in patients from the Vantris group. However, no statistical difference was demonstrated regarding the obstruction rate in the homogenous group with relation to gender, age and reflux grade group of patients. Moreover, univariate analysis revealed that Grade V reflux, the presence of beak sign on the reviewed pretreatment, and inflamed bladder mucosa upon injection were significant independent risk factors leading to obstruction.

DISCUSSION

This study suggested that the underlining ureteral pathology lead to UVJ obstruction following Vantris injection. There was increased collagen deposition in the juxtavesical segment of the obstructive ureters following Vantris injection. Furthermore, these findings were similar to those discovered in patients who underwent endoscopic correction with Deflux, and in patients who required ureteral reimplantation due to primary obstructive megaureter. Additional biopsies from the muscularis propria adjacent to the injection site showed no significant abnormalities, ironing out the fact that Vantris did not led to adverse tissue reaction following injection. Univariate analysis further ironed out the hypothesis that underlying ureteral pathology was responsible for the increased incidence of UVJ obstruction and demonstrated that Grade V reflux, the presence of beak sign on the reviewed pretreatment VCUG, and inflamed bladder mucosa upon injection were significant independent risk factors leading to obstruction.

CONCLUSION

Data showed that Vantris injection did not lead to any different ureteral fibrosis or inflammatory changes to the tissue augmenting substances utilized in past and present clinical practice, and therefore did not seem to increase the incidence of UVJ obstruction. High reflux grade, presence of obstructive/refluxing megaureter and inflamed bladder mucosa were the only statistically significant and independent predictive factors for UVJ obstruction following endoscopic correction of VUR.

Changing bulking agent may require change in injection volume for endoscopic treatment of vesicoureteral reflux

Introduction:

Various bulking agents were utilized for endoscopic correction of VUR. A study reviewing multi-institutional data showed that the amount of injection material has increased over time with the purpose of improving success rates, which also resulted in costs. We noticed an opposite trend in our center since we started using a new bulking agent. The aim of this study was to evaluate evolution of our practice with different bulking agents.

Patients and Methods:

Records of VUR patients who underwent subureteric injection with polyacrylate polyalcohol copolymer (PPC) and dextronomere hyaluronic acide (DxHA) between 2005 and 2014 were reviewed. Variation of different parameters throughout the study period was evaluated along with the success rate. Success was defined as complete resolution of reflux.

Results:

A total of 260 patients with 384 refluxing units were included. The success rate was higher in PPC group compared to DxHA group. There was no statistically significant difference between years regarding distribution of VUR grade, body weight, patient height, and age in PPC group. Despite significant reduction in injection volume, success rate did not decrease through the years with PPC.

Conclusion:

Different bulking agents may require different injection volumes to achieve the same success rate in endoscopic treatment of vesicoureteral reflux. Habits gained with previous experience using other materials should be revised while using a new agent.

Long-Term (>10 Years) Results After Endoscopic Injection Therapy for Vesicoureteral Reflux

OBJECTIVE

Endoscopic injection is an accepted alternative for the treatment of vesicoureteral reflux (VUR) with the most commonly used agent being dextranomer/hyaluronic acid (Dx/HA). There are few reports on very long-term results after this treatment, although the biodegradable nature of the product could indicate that results might deteriorate on the long term. We, therefore, decided to evaluate the efficacy of Dx/HA copolymer endoscopic injection, in terms of recurrence of febrile urinary tract infections (fUTIs) in children, with a follow-up of at least 10 years.

MATERIALS AND METHODS

We analyzed the medical data of all children who were diagnosed with VUR and underwent endoscopic injection with >10 years follow-up, in two University Hospitals. We reviewed their medical files and then contacted patients by phone.

RESULTS

We found 68 patients who had undergone endoscopic treatment of VUR with a follow-up of minimum 10 years. We were able to contact 53 of these patients of whom 38 were girls, and 36 had bilateral VUR with a total of 89 ureteral units. Mean age at surgery was 86 months (26-136). Mean follow-up was 12.5 years (range: 10.5-15). No child presented postinjection obstruction. Thirteen patients presented with a recurrence of fUTI during the postoperative course of whom 8 presented persistent VUR. All recurrences of fUTI occurred within the first 5 years of follow-up. Four underwent a second injection and 4 underwent open reimplantation. Success rate per patient was 85%.

CONCLUSION

Results of endoscopic injection using Dx/HA remain stable over time (>10 years). In our series, recurrences of fUTI occur within the first 5 years of follow-up.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level III.

Endoscopic correction of vesicoureteral reflux in children using polyacrylate-polyalcohol copolymer (Vantris): 5-years of prospective follow-up

Introduction

The endoscopic correction of vesicoureteral reflux (VUR) in children is a currently well accepted therapy in many pediatric urology centers. Polyacrylate-polyalcohol copolymer (PPC), namely Vantris^®, is one of the tissue-augmenting substances used for endoscopic reflux therapy. The aim of this study was to evaluate the results with PPC in children.

Material and methods

From 2012 to 2016, 125 children (73 girls and 52 boys) aged 0.6–17.9 years (mean 4.9 ±3.58) were treated with PPC. VUR was unilateral in 64 and bilateral in 61 patients, comprising 197 renal refluxing units (RRUs) grades: II in 72, III in 50, IV in 33 and V in 42. Of these primary reflux was present in 132 RRUs and 65 were complex cases. Voiding cystourethrogram (VCUG) was done 3 months after procedure.

Results

Follow-up was completed in 89.6% of patients (112 children), and 89.8% of RRUs (177 out of 197). Reflux resolved in 86.4% of RRUs after single injection, in 99.4% after second and in 100% after the third. The only significant, but serious complication observed was late ureteral obstruction after PPC injection correcting high grade reflux, which required ureteral re-implantation. This complication was found in 9 out of 112 children (8%), and in 11 out of 177 RRUs (6.2%), 1.1 -2.9 years (mean 2 ±0.7) after the PPC injection. The longest follow-up reaches 4.5 years.

Conclusions

Our data show that the PPC injection is an effective procedure for treating all grades of VUR with high success rate. However, because of the possibility of late ureteral obstruction, which requires ureteroneocystostomy, long-term follow-up is mandatory.

Endoscopic antireflux surgery leading to obstruction in pediatric renal transplant patients

To describe a multicenter experience with management of ureteral obstruction after injection of Dx/HA for VUR in pediatric renal transplant patients. The records of all pediatric renal transplant patients who underwent Dx/HA injection for VUR and had subsequent obstruction were identified, and the management and outcomes were reviewed. Follow-up ranged from 1 to 10 years. There were four patients identified, all of whom had a history of rising creatinine, recurrent UTI, and increasing hydronephrosis which led to the diagnosis of high-grade VUR. Obstruction was diagnosed within 24-72 hours after injection in three patients. One patient was asymptomatic, and rising creatinine and hydronephrosis were noted 1 month after injection. One patient was managed expectantly, while three patients underwent ureteral stent placement. After the stent was removed, one patient went on to open reimplant due to delayed obstruction, the second patient with voiding dysfunction is currently managed with an indwelling ureteral stent and may require further definitive surgery, the third patient recovered, and the fourth is being observed. Our cases illustrate that despite initial successful management of the obstruction in some, delayed obstruction is possible and may necessitate open reimplant. It is imperative that these patients have close follow-up after Dx/HA.

Late ureteral obstruction in an adult who had STING/Teflon in childhood: Should we expect an epidemic?

We present a case of left renal colic in a 25-year-old female patient. She had subureteral injection of Teflon (STING) at the age of 10 due to vesico-ureteral reflux (VUR) disease and recurrent urinary tract infections. Renal colic was the result of late ureteral obstruction due to Teflon-induced periureteral foreign body reaction. To our knowledge, this is the longest interval between STING and ureteral obstruction reported and the first case of delayed ureteral obstruction caused by Teflon. Monitoring the upper tracts of patients after STING should go beyond childhood.

Ureteric patency after Deflux® injection for the treatment of vesicoureteric reflux in children confirmed by a novel epidural catheter-assisted endoscopic technique

PURPOSE

We present EDCAT (epidural catheter-assisted Deflux(®) treatment) for treating vesicoureteral reflux (VUR) and confirming ureteric patency after Deflux(®) treatment.

METHODS

We treated 147 ureters in 101 children (M:F 62:39; VUR ≤ grade III: n = 72; VUR ≥ grade IV: n = 75) using EDCAT between 2011 and 2014. EDCAT involves injecting 1-3 mL of diluted indigo carmine solution through an epidural anesthesia catheter inserted into the Deflux(®)-treated ureter and observing for up to 15 min to confirm patency.

RESULTS

For EDCAT, mean age was 4.9 years and mean operative time was 30.1 ± 12.1 min; overall cure of VUR after initial treatment was 87.7 % for VUR grades I-V, 88.9 % for VUR ≤ grade III, and 86.6 % for VUR ≥ grade IV; VUR was cured in 129/147 after 1 treatment, 7/18 after 2 treatments, 7/11 after 3 treatments, and persistent in 4/4. We experienced 1 case of obstruction after an EDCAT catheter was removed before confirming patency. EDCAT catheters were left overnight in 2 ureters in 2 cases when patency could not be confirmed after 15 min to prevent obstruction. Both did not develop obstruction. Four ureters with recurrence of VUR (all grade ≤ II) are being observed.

CONCLUSION

EDCAT allows ureteric patency to be confirmed immediately and prevents obstruction.

Postoperative ureteral obstruction after endoscopic treatment for vesicoureteral reflux

Purpose

We undertook this study to evaluate the incidence, risk factors, management, and outcome of postoperative ureteral obstruction after endoscopic treatment for vesicoureteral reflux (VUR).

Materials and Methods

Ninety patients undergoing endoscopic treatment for VUR were retrospectively reviewed and classified into two groups according to ureteral obstruction: the nonobstruction group (83 cases, 122 ureters; mean age, 7.0±2.8 years) and the obstruction group (7 cases, 10 ureters; mean age, 6.2±8.1 years). We analyzed the following factors: age, sex, injection material, laterality, voiding dysfunction, constipation, renal scarring, preoperative and postoperative ultrasound findings, endoscopic findings, injection number, and injection volume. Additionally, we reviewed the clinical manifestations, natural course, management, and outcome of ureteral obstruction after endoscopic treatment.

Results

The incidence of ureteral obstruction after endoscopic treatment was 7.6% (10/132 ureters). The type of bulking agent used and injection volume tended to be associated with ureteral obstruction. However, no significant risk factors for obstruction were identified between the two groups. Three patients showed no symptoms or signs after the onset of ureteral obstruction. Most of the patients with ureteral obstruction experienced spontaneous resolution within 1 month with conservative therapy. Two patients required temporary ureteral stents to release the ureteral obstruction.

Conclusions

In our experience, the incidence of ureteral obstruction was slightly higher than in previous reports. Our study identified no predictive risk factors for developing ureteral obstruction after endoscopic treatment. Although most of the ureteral obstructions resolved spontaneously within 1 month, some cases required drainage to relieve symptoms or to prevent renal function deterioration.

Acute kidney injury due to bilateral ureteral obstruction in children

Bilateral ureteral obstruction in children is a rare condition arising from several medical or surgical pictures. It needs to be promptly suspected in order to attempt a quick renal function recovery. In this paper we concentrated on uncommon causes of obstruction, with the aim of giving a summary of such multiple, rare and heterogeneous conditions joint together by the common denominator of sudden bilateral ureteral obstruction, difficult to be suspected at times. Conversely, typical and well-known diseases have been just run over. We considered pediatric cases of ureteral obstruction presenting as bilateral, along with some cases which truly appeared as single-sided, because of their potential bilateral presentation. We performed a review of the literature by a search on PubMed, CrossRef Metadata Search, internet and reference lists of single articles updated to May 2014, with no time limits in the past. Given that we deal with rare conditions, we decided to include also papers in non-English languages, published with an English abstract. For the sake of clearness, we divided our research results into 8 categories: (1) urolithiasis; (2) congenital urinary tract malformations; (3) immuno-rheumatologic causes of ureteral obstruction; (4) ureteral localization of infections; (5) other systemic infective causes of ureteral obstructions; (6) neoplastic intrinsic ureteral obstructions; (7) extrinsic ureteral obstructions; and (8) iatrogenic trigonal obstruction or inflammation. Of course, different pathogenic mechanisms underlay those clinical pictures, partly well-known and partly not completely understood.