Obstruction of a Dysmorphic Ureter Following Dextranomer/Hyaluronic Acid Copolymer

Evaluation of renal oxygenation by near-infrared spectroscopy during endoscopic injection of bulking agents in children with vesicoureteral reflux

BACKGROUND

Near infrared spectroscopy (NIRS) is the measuring of regional tissue oxygenation (rSO2) by interpreting oxyhemoglobin and deoxyhemoglobin signals that come back by transmitting near infrared light to tissues. The effect of endourological interventions on renal perfusion in children is largely unknown.

AIMS

To evaluate the effects of endoscopic injection of bulking agents (EIBA) for vesicoureteral reflux (VUR) on renal oxygenation (RO) using renal NIRS monitoring, which shows renal perfusion and oxygenation changes.

STUDY DESIGN

Case-control study.

METHODS

Group I had bilateral inguinal surgery, Group II cystoscopy, and Group III, EIBA for VUR with 30 patients in each group. During the operation, vital signs, peripheral oxygen saturation, end-tidal carbon dioxide, and renal regional oxygen saturation index (rSO2) values by bilateral renal NIRS monitoring were recorded. NIRS values before induction (T0) to postoperative (Tend) were determined. A 20% or more reduction in renal rSO2 (%20↓rSO2) was considered significant. Group III was also evaluated as subgroup III-A (not having "%20↓rSO2") and subgroup III-B ("%20↓rSO2").

RESULTS

The rSO2 decrease was observed in the first 5 min for both sides in group III. The most significant drop was at T30 for the right kidney and a significant decrease in rSO2, 20% or more, was observed in 6 renal units of 4 patients having higher SFU grading and renal scar in group III.

CONCLUSION

EIBA may transitionally impair renal oxygenation. Higher SFU grading and renal scar may increase the risk of renal hypoxia during EIBA.

Endoscopic Correction of Reflux Utilizing Polyacrylate Polyalcohol Bulking Copolymer (Vantris) as a Tissue Augmenting Substance: Lessons Learned Over the 10 Years of Experience

Objectives: To prove the hypothesis that modifying the endoscopic correction of vesicoureteral reflux (VUR) technique (STING procedure) and sharpening its contraindications, lead to increased success rate and decline in the complication rate. Materials and Methods: All patients that underwent endoscopic correction of VUR utilizing Vantris were divided into two groups according to procedure date; before 2015 and 2015-2019. Indication for treatment included persistent high-grade VUR or breakthrough infections. Contraindications included voiding dysfunction, active infection and since 2015 suspicion for obstructive/refluxing ureterovesical junction (UVJ) presented by "beak" sign on voiding cystourethrography (VCUG). Follow-up regiment included ultrasound and VCUG at predetermined intervals. Results: The first group included 215 (158 girls and 57 boys) children with mean age of 4.8 ± 2.8 years who underwent endoscopic correction between 2009 and 2015 and the second group included 42 children (28 girls and 14 boys) with mean age of 3.9 ± 2.1 years who underwent surgery between 2015 and 2019. In the first group, VUR was unilateral in 74 patients and bilateral in 132 comprising 338 renal refluxing units. In the second group, VUR was unilateral in 14 patients and bilateral in 30 comprising 74 RRUs. In the first group reflux was corrected in 317 (94.9%) RRUs after a single injection, after the second in 7 (2.1%) RRUs. In seven (2.1%) RRUs, reflux downgraded to Grade I-II. Three RRUs (0.9%) failed endoscopic correction and required ureteral reimplantation. Nine (2.7%) RRUs developed UVJ obstruction. In the second group reflux was corrected in 61 (82.4%) RRUs after a single injection, after the second in 12 (16.2%) RRUs. In one (1.4%) RRU, endoscopic correction failed and required ureteral reimplantation. None of the patients developed UVJ obstruction. Reflux correction has led to the significant decrease of febrile urinary tract infection (UTI) in both groups. Conclusions: Our data indicate that endoscopic injection utilizing Vantris is safe and long durable procedure. Although utilizing the proper technique and contraindication criteria, the rates of post procedural VUJ obstruction is null.

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

INTRODUCTION

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

AIM

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

STUDY DESIGN

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

RESULTS

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

DISCUSSION

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

CONCLUSIONS

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

Asymptomatic bilateral delayed ureteral obstruction following dextranomer/hyaluronic acid copolymer (Deflux) injection for vesicoureteral reflux.: A case report

We here present a case of a 4-year-old girl who exhibited an asymptomatic bilateral de novo hydroureteronephrosis seven months after undergoing endoscopic treatment for bilateral vesicoureteral reflux. The child underwent an open bilateral reimplantation. Intraoperatively, a 14 mm nodule on the right and a 16 mm on the left located periureteral orifice were observed. When a small incision was made on nodules, a yellowish-white mucinous fluid flowed out.

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.

New bulking agent for the treatment of vesicoureteral reflux: Polymethylmethacrylate/dextranomer

Purpose

The aim of this study was to report preliminary results of endoscopic treatment of vesicoureteral reflux in children with a single injection of a new bulking agent, cross-linked dextran and polymethylmethacrylate mixture.

Materials and Methods

We performed a single-center, single surgeon, prospective, off-label study using polymethylmethacrylate/dextranomer to treat vesicoureteral reflux. All patients underwent endoscopic injection, followed by renal ultrasound and voiding cystourethrogram at 3 months postoperatively to identify de novo or worsening hydronephrosis and vesicoureteral reflux correction (to Grade 0 or I).

Results

Eighteen patients underwent injection of polymethylmethacrylate/dextranomer at our institution between April 2013 and December 2013. Ten were males and eight were females, with a median age of 58 months (range, 6 months to 5 years). Vesicoureteral reflux was unilateral in three patients and bilateral in 15, for a total of 33 renal refluxing units. Vesicoureteral reflux was Grade I in one renal refluxing unit, Grade II in 12, Grade III in 16, and Grade IV in four. Mean injected volume was 0.86 mL. Reflux was corrected in 23 renal refluxing units (69.7%) according to the 3-month voiding cystourethrogram. Complications included urinary retention in one patient. Mild pyelectasis was noted in one patient at 3 months, which spontaneously resolved 3 months later.

Conclusions

Our short-term data show that polymethylmethacrylate/dextranomer injection can be used to treat vesicoureteral reflux with comparable efficacy to other substances currently used and a low rate of complications. Long-term follow-up is required to confirm the usefulness of this material in treating vesicoureteral reflux.

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 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.

[Secondary megaureter: A rare complication of Deflux® endoscopic management of vesicoureteral reflux in children]

Endoscopic management is the gold standard for symptomatic low-grade vesicoureteral reflux (VUR) in children. Deflux^® (hyaluronic acid/dextranomer) injection is highly effective and has very few complications. We report on two cases of secondary megaureter after Deflux^® injections. In the first case, a boy presented with Grade 4 VUR. He received a bilateral Deflux^® injection with a total of three syringes. The postoperative ultrasound was normal. However, a check-up ultrasound 3 years later showed a significant ureteropyelocalyceal dilatation, with stasis and decreased renal function on scintigraphy, the reason why antireflux surgery (Cohen procedure) was performed. In the second case, a girl diagnosed with bilateral VUR at birth received bilateral injections with one syringe on each side at the age of 12 months. One month later, the ultrasound showed a dilation of the distal ureters (diameter of the right ureter, up to 10mm; left ureter, up to 6.7mm). The child underwent surgery 8 months later (Cohen procedure) because of iterative pyelonephritis and persistent ureter dilatation. Only one previous case has been described in the literature. In our experience, this complication has occurred only twice in 452 injections (4‰). In conclusion, endoscopic treatment with hyaluronic acid/dextranomer injection is a minimally invasive procedure that improves the situation in cases of VUR. It has few complications. Other than failure, there is a low risk of secondary expansion requiring, in our opinion, ultrasound verification over the long term.

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.

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.

Endoscopic correction of complex cases of vesicoureteral reflux utilizing Vantris as a new non-biodegradable tissue-augmenting substance

PURPOSE

We aimed to evaluate prospectively the efficacy of Vantris as a new non-biodegradable tissue-augmenting substance in children with complex cases of VUR.

MATERIALS AND METHODS

Over the last 4 years, 37 children (28 female and 9 male) with a mean age of 5.8 ± 3.1 years (mean ± SD) underwent endoscopic correction of complex VUR. A total of 38 renal refluxing units (RRU) was treated as 5 had persistent reflux after open surgery, 16 had duplication, 4 had Hutch diverticulum, 6 had small poorly functioning kidneys (less than 20% of relative renal function) with grade V VUR, 2 had ureterocele after puncture, 3 had persistent stump reflux, 1 had prune belly syndrome, and 1 had urogenital sinus. VUR was Grade I in 2, Grade II in 9, Grade III in 11, Grade IV in 10, and Grade V in 6 RRU, respectively.

RESULTS

The reflux was corrected in 34 (89.4%) RRU after a single injection, after second injection in 2 (5.3%) RRU. In 2 (5.3%) RRU, VUR downgraded to Grade I (1RRU) and Grade II (1RRU) and they were taken off antibiotic prophylaxis. VCUG was performed in 11 (73.3%) of 15 children who completed 1 year and in 3 (33.3%) of 9 who completed 3 years of follow up as a part of the routine protocol. None showed VUR recurrence. US demonstrated normal appearance of kidneys in all patients.

CONCLUSION

Our data show that Vantris injection provides a high level of reflux resolution in complex cases of VUR.

Endoscopic correction of vesicoureteral reflux in children with a solitary kidney: the risk of obstruction

PURPOSE

We aimed to review patients with a solitary kidney and ipsilateral vesicoureteral reflux (VUR) who underwent endoscopic correction of VUR (ECVUR) and to evaluate the prevalence of obstruction in this group of patients.

MATERIALS AND METHODS

We retrospectively reviewed the files of all patients who underwent ECVUR at our center between January 2000 and June 2011. Only patients with a solitary kidney and ipsilateral VUR were included.

RESULTS

Thirteen patients met our criteria. Two patients (15.38%) developed obstruction post-ECVUR. Both patients developed anuria in the first 24 h after surgery and required intervention. Two patients (15.38%) had increasing hydroureteronephrosis that was discovered on follow-up ultrasound, with no symptoms or signs of obstruction. Both were managed conservatively.

CONCLUSION

Our results showed a higher percentage of obstruction post-ECVUR in patients with a solitary kidney (15.38%), who required immediate intervention. Thus, we recommend giving clear instructions to parents of patients with VUR and a solitary kidney post-ECVUR before discharge from the hospital regarding decreased urine output and loin pain. We recommend a follow-up ultrasound to rule out obstruction and detect new-onset hydronephrosis.

Postoperative ureteral obstruction after endoscopic treatment of vesicoureteral reflux with polyacrylate polyalcohol copolymer (Vantris®)

PURPOSE

To investigate the incidence and presentations of ureteral obstruction following periureteral injection of polyacrylate polyalcohol copolymer (PPC) for the treatment of vesicoureteral reflux (VUR).

MATERIALS AND METHODS

From Jan 2010 to Dec 2012, 88 patients (28 male, 60 female) with 128 renal refluxing units (RRU), 131 ureters and a mean age of 6.7 ± 5.9 years (range: 4 months to 32 years) underwent endoscopic correction of their VUR, using PPC. Exclusion criteria were dysmorphic appearing distal ureter, extravesical position of the ureteral orifice, persistent urethral obstruction (e.g. after previous valve ablation) and severe bladder trabeculation, making ureteral orifice unidentifiable. Patients were followed up by ultrasound one month after the injection and then every three months. Cystography was performed 3 months post-operation. Mean follow-up time was 13.1 ± 6.8 months (range: 3-27 months).

RESULTS

Two patterns of obstruction were observed: early, during the first 3-4 days post-operation, in four patients (4 ureters; 3%) which was associated with transient hydroureteronephrosis (HUN) in 2 patients (2 ureters; 1.5%); and late-onset obstruction in 3 patients (4 ureters; 3%) which appeared 3 months to 1 year after surgery. It manifested itself by urinary tract infection and uremia in one patient with bilateral obstruction but was asymptomatic in the other two. Early obstruction was managed expectantly and resolved in 3-12 months; however, late-onset obstruction needed catheter placement or open ureteroneocystostomy.

CONCLUSIONS

Patients who undergo endoscopic treatment for their VUR using PPC need long-term follow up until the safety of this substance is confirmed.

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

OBJECTIVE

To present our cases of ureteral obstruction after endoscopic treatment of vesicoureteral reflux (VUR) with dextranomer/hyaluronic acid (Dx/HA).

PATIENTS AND METHODS

We collected data from patients who had suffered ureteral obstruction after endoscopic treatment of VUR with Dx/HA in our institution.

RESULTS

From April 2002 to April 2011 we treated endoscopically 475 ureters with VUR, and detected 5 ureteral obstructions. Median age at reflux treatment was 39 months. Reflux grade before treatment was III in one patient and IV in four. Three ureterovesical junctions (UVJ) were blocked after a second endoscopic treatment. The median of Dx/HA injected was 1 ml (0.6-1.1). In two patients ureteral obstruction presented acutely and was treated with a ureteral stent. In the other three, the ureteral obstruction appeared gradually and was detected by ultrasound scans and MAG3 diuretic renogram; one underwent nephrectomy because of poor renal function, and the other two were treated with endoscopic dilatation of the UVJ. In all these patients both reflux and obstructions have resolved.

CONCLUSIONS

On preoperative cystography, three of the patients had a narrowed distal ureter, and probably had a refluxing and obstructive megaureter. Other causes are not clear, except for those patients with acute presentation in whom edema of the UVJ was found. Ureteral obstruction after endoscopic treatment of VUR is rare. Endoscopic intervention such as ureteral stent placement or high-pressure balloon dilatation of the UVJ has good results as a treatment of acute and delayed obstruction.

Ureteral obstruction following injection of dextranomer/hyaluronic acid copolymer: an infrequent but relevant complication

PURPOSE

To report our experience with ureteral obstruction after injection of dextranomer/hyaluronic acid copolymer (Dx/Ha) to treat vesicoureteral reflux, and analyze its possible causes, management and outcome.

MATERIALS AND METHODS

Retrospective review of patients undergoing injection of Dx/Ha. The charts of patients with clinically relevant ureteral obstruction were evaluated for indications, prior interventions, technique of injection and volume injected. Video recordings obtained during injection were analyzed to detect possible technical errors.

RESULTS

Fifty-four patients (87 ureters) were treated with Dx/Ha injection in a 5-year period. Five ureters (5.7%) in five patients (9.3%) developed significant ureteral obstruction requiring intervention. Manifestations of obstruction included pain in two patients, urinary tract infections in one and loss of function in one. Increased serum creatinine was observed in a patient with a transplanted kidney. Four obstructions resolved spontaneously (two after percutaneous nephrostomy, two after placement of a ureteral stent) and one required reimplantation. Review of the videos did not reveal any deviation from the usual technique. The volumes injected in the obstructed cases (0.7-1.2 ml) were in the usual range.

CONCLUSIONS

In this series, the incidence of post Dx/Ha ureteral obstruction was higher than previously reported. Although 4/5 cases resolved spontaneously, they required drainage to relieve symptoms or to improve renal function. Surgeons need to be aware of this complication and include its possible occurrence in the informed consent obtained prior to injection.

Asymptomatic chronic partial obstruction of a normal ureter following dextranomer/hyaluronic acid copolymer (Deflux®) injection for grade I vesicoureteral reflux

Endoscopic management of vesicoureteral reflux with dextranomer/hyaluronic copolymer (Deflux(®), Oceana Therapeutics, Inc., Edison, NJ, USA) has gained widespread acceptance with increasing success rates and minimal morbidity. Formation of a pseudocapsule and calcification are known histologic changes at the injection site. Postoperative ureteral obstruction has been reported in cases of severe voiding dysfunction, neurogenic bladder and abnormal ureteral anatomy. We present a case of chronic asymptomatic obstruction in a normal ureter following injection of 0.7 ml Deflux.

Endoscopic treatment of vesicoureteral reflux: current practice and the need for multifactorial assessment

Vesicoureteral reflux (VUR) affects around 1% of all children. It carries an increased risk of febrile urinary-tract infections (UTIs) and is associated with impaired renal function. Antibiotic prophylaxis is an established approach to managing the condition, but it does not protect against UTI and encourages bacterial resistance. Ureteral re-implantation (open surgery) is a relatively traumatic procedure typically requiring hospitalization, and there is a risk of significant post-treatment complications. Endoscopic treatment with NASHA/Dx gel (Deflux®) is minimally invasive, well tolerated and provides cure rates approaching those of open surgery: 80-90% in several studies. It has also been shown to be effective in a variety of 'complicated' cases. Thus, endoscopic treatment is generally preferable to open surgery and long-term antibiotic prophylaxis. Non-treatment of VUR is being discussed as an alternative option, although this mainly appears suitable for children with low-grade reflux and normal kidneys. A new approach to managing VUR may be considered, with treatment decisions based not only on the grade of reflux but also on factors such as age, sex, renal scarring and bladder dysfunction. Open surgery would be reserved only for use in the 10-15% of children not responding to endoscopic treatment and those with severe ureteral anomalies.

Transurethral injection therapy with carbon-coated beads (Durasphere®) for treatment of recurrent pyelonephritis in kidney transplant patients with vesico-ureteral reflux to the allograft

INTRODUCTION AND OBJECTIVES

Recurrent transplant pyelonephritis (RTP) secondary to vesico-ureteral reflux (VUR) to the transplant kidney (KTx) remains a significant cause of infectious complications with impact on patient and graft outcomes. Our objective was to verify the safety and efficacy of transurethral injection of Durasphere(®) to relieve RTP secondary to VUR after renal transplantation.

PATIENTS AND METHODS

Between June 2004 and July 2008, eight patients with RTP (defined as two or more episodes of pyelonephritis after transplantation) and VUR to the KTx were treated with subureteral injections of Durasphere(®). The mean age at surgery was 38.8 ± 13.8 yr (23-65). The patients were followed regularly every six months. The mean interval between the KTx and the treatment was 76 ± 74.1 (10-238 months). The mean follow-up was 22.3 ± 16.1 months (8-57 months).

RESULTS

Six patients (75%) were free of pyelonephritis during a mean period of follow-up of 23.2 ± 17.1 months (8-57 months). Two of them had no VUR and four cases presented with G II VUR (pre-operative G IV three cases and one case G III). In one case, symptomatic recurrent cystitis made a second treatment necessary. This patient remained free of infections for three yr after the first treatment and for 18 months after the second treatment. Of the remaining two patients, one had six episodes of RTP before treatment in a period of three yr and only two episodes after treatment in two yr of follow-up. The last case had a new episode of pyelonephritis five months after treatment.

CONCLUSIONS

Transurethral injection therapy with Durasphere(®) is a safe and effective minimally invasive treatment option for KTx patients with recurrent RTP. A second treatment seems to be necessary in some cases.

Endoscopic treatment of vesicoureteral reflux: Current status

Vesicoureteral reflux (VUR) affects around 1% of all children. It carries an increased risk of febrile urinary tract infections (UTIs) and is associated with impaired renal function. Endoscopic treatment with NASHA/Dx gel (dextranomer microspheres in a stabilized hyaluronic acid-based gel of nonanimal origin) is minimally invasive, well tolerated and provides cure rates approaching those of open surgery: approximately 90% in several studies. It has also been shown to be effective in a variety of 'complicated' cases. Endoscopic treatment is therefore considered preferable to open surgery and long-term antibiotic prophylaxis. Nontreatment of VUR is being discussed as an alternative option, whereby children are treated with antibiotics only when UTIs occur. Considering all the available evidence, however, active intervention with endoscopic treatment remains preferable. A new approach to managing VUR may nevertheless be considered, with treatment decisions based not only on the grade of reflux, but also factors such as age, sex, renal scarring, and bladder dysfunction. Open surgery would be reserved for use only in the ( approximately )10% of children not responding to endoscopic treatment, and patients with refluxing primary megaureter.

Transurethral injection therapy with dextranomer/hyaluronic acid copolymer (Deflux) for treatment of secondary vesicoureteral reflux after renal transplantation

BACKGROUND AND PURPOSE

Secondary vesicoureteral reflux (SVUR) after renal transplantation may cause recurrent urinary-tract infections (UTI) and loss of renal function. There are only a few reports on the endoscopic treatment of SVUR by transurethral injection therapy. This is the first report of transurethral injection of dextranomer/hyaluronic acid copolymer (Deflux; Q-Med Scandinavia, Uppsala, Sweden) to relieve SVUR after renal transplantation.

PATIENTS AND METHODS

Between November 2003 and October 2005, four women were treated for SVUR with transurethral injections of dextranomer/hyaluronic acid copolymer. All patients had deterioration of renal function attributable to SVUR, recurrent UTI, or both. The mean follow-up was 29 months (range 16-38 months).

RESULTS

Initially, SVUR was corrected in all patients. Recurrent SVUR made a second treatment necessary in two patients. Three patients had no signs of SVUR 15, 27, and 36 months after the treatment. Renal function remained stable in these patients, and two were free of UTI. One of the patients who received two Deflux injections developed a filiform stenosis of the distal ureter, which was corrected by ureteropyeloplasty with the native ureter.

CONCLUSION

Transurethral injection therapy with Deflux is a minimally invasive treatment option for patients with SVUR after renal transplantation. A second treatment seems to be necessary in some cases. Complications such as ureteral obstruction may occur.

Histopathological Changes Associated With Dextranomer/Hyaluronic Acid Injection for Pediatric Vesicoureteral Reflux

PURPOSE

Few studies have examined the medium and long-term histological changes associated with periureteral injection of dextranomer/hyaluronic acid copolymer (Deflux(R)). We present the results of a histological review of a series of distal ureteral excisions in patients undergoing ureteroneocystostomy after failed dextranomer/hyaluronic acid injection.

MATERIALS AND METHODS

All patients undergoing ureteroneocystostomy after failed dextranomer/hyaluronic acid injection(s) at 1 institution were eligible for this study. Excised ureteral segments were histologically examined by a single urological pathologist. An immunohistochemical battery was used for each specimen, including hematoxylin and eosin, CD3, CD20, MIB-1 and trichrome stains. Pathological criteria included the presence, location and intensity of fibrosis, giant cell reaction, chronic inflammation, free dextranomer/hyaluronic acid, and CD3, CD20 and MIB-1 staining. Pathological features were correlated with the time from injection to surgical excision.

RESULTS

The ureters of 16 children with a mean age of 4.5 years were examined. Median time from injection to implant excision was 8 months. Giant cell reaction was present in 94% of patients and it was typically located in the serosa. No histological or immunophenotypical feature correlated with the duration of implantation except CD3+ and CD20+ lymphocyte counts, which increased with time from injection (p = 0.06 and 0.02, respectively).

CONCLUSIONS

Dextranomer/hyaluronic acid appears to be stable and safe for use after 3 to 22 months of followup of subureteral injection. The periureteral inflammatory reaction increases with time, although no increases in nuclear turnover or fibrosis were detected.

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

PURPOSE

Factors influencing outcomes of dextranomer/hyaluronic acid injection for vesicoureteral reflux remain poorly defined. We performed multivariate analysis of the experience of 1 surgeon (WS).

MATERIALS AND METHODS

The study group contained 168 patients and 259 refluxing units. Goal of injection was coaptation of the orifice with creation of a volcanic mound. Outcomes were determined by cystography obtained 12 weeks following injection. Intraoperative photographs of mounds were independently reviewed by 2 authors (WS, SY) without knowledge of results, and classified as "satisfactory" or "other." Univariate and multivariate logistic regression analysis was done evaluating influence of gender, age, voiding dysfunction, reflux grade, unilateral vs bilateral reflux, ureteral duplication, orifice laterality, subureteral vs intraureteral injection, volume injected and mound appearance.

RESULTS

A single injection resolved reflux in 70% of patients and 78% of ureters. Additional injection resulted in overall success in 82% of patients and 86% of ureters. Multivariate analysis demonstrated that reflux grade, volume of dextranomer/hyaluronic acid injected and mound appearance correlated with outcomes. A satisfactory mound was achieved in 81% of ureters, of which 87% no longer refluxed.

CONCLUSIONS

The ability to create a satisfactory mound was the most important factor determining success of dextranomer/hyaluronic acid injection. Increasing reflux grade was associated with a decreased likelihood of achieving a volcanic mound, and increasing volume injected suggested difficulty in creating a mound.

Postoperative Ureteral Obstruction After Subureteral Injection of Dextranomer/Hyaluronic Acid Copolymer

PURPOSE

Subureteral injection of dextranomer/hyaluronic acid copolymer is widely accepted for the treatment of primary vesicoureteral reflux. Few studies document the incidence of surgically relevant postoperative obstruction or the characteristics of patients at risk.

MATERIALS AND METHODS

Four institutions had reported surgically relevant postoperative obstruction to representatives of Q-Med Scandinavia, the manufacturers of Deflux (dextranomer/hyaluronic acid). All children undergoing dextranomer/hyaluronic acid injection at these institutions were evaluated in this study. Patients requiring postoperative stenting were retrospectively reviewed for pertinent history, volume injected, technique of injection, duration of symptoms before intervention, duration of intervention and final outcome.

RESULTS

A total of 745 patients (1,155 ureters) underwent injection. Five patients (6 renal units, 7 ureters) required stenting for obstructive symptoms and hydronephrosis, of whom 4 immediately became symptomatic. All patients had been injected with up to 1 ml dextranomer/hyaluronic acid. Four patients (80%) had either a neurogenic bladder or dysfunctional voiding. All stents were placed and removed without complications, with complete resolution of symptoms in all patients. Length of stenting ranged from 2 to 6 weeks. No patient required open surgery. One of 2 patients undergoing postoperative voiding studies had development of recurrent vesicoureteral reflux.

CONCLUSIONS

Dextranomer/hyaluronic acid injection is associated with a small risk of postoperative ureteral obstruction requiring endoscopic intervention, with an overall incidence of less than 0.7% of patients injected. Patients with voiding dysfunction or neurogenic bladder may be at increased risk. Intervention with temporary ureteral stenting is effective, technically simple and curative.

Renal ultrasound studies after endoscopic injection of dextranomer/hyaluronic acid copolymer for vesicoureteral reflux

OBJECTIVES

To examine the outcomes of renal ultrasound studies after subureteral injection of dextranomer/hyaluronic acid copolymer and provide recommendations for postoperative management of vesicoureteral reflux (VUR).

METHODS

Pediatric patients aged 15 years or younger with uncomplicated primary VUR were recruited for endoscopic treatment with dextranomer/hyaluronic acid gel. After undergoing the procedure, patients were instructed to continue prophylactic antibiotic treatment until a follow-up voiding cystourethrogram was obtained 2 weeks or more after treatment. VUR resolution was defined as grade 0. Repeat endoscopic injection was offered to patients with persistent VUR. Postoperative renal ultrasound scans were obtained on the same day as the voiding cystourethrogram.

RESULTS

Of 120 patients treated, 6 were lost to follow-up and 14 had not yet undergone the posttreatment evaluation. The 100 remaining patients (efficacy population) had a mean age of 4.2 years (range 0.5 to 15), and the median reflux grade was 2 (range 1 to 5). The overall VUR resolution rate for the patients was 87% after endoscopic injection. Of 100 patients, 88 achieved complete resolution after a single injection and 19 required a repeat injection. Of the 100 patients who underwent postoperative ultrasound examination, none demonstrated renal ultrasound changes consistent with significant ureteral obstruction or renal parenchymal changes.

CONCLUSIONS

Renal ultrasound studies after endoscopic treatment with dextranomer/hyaluronic acid gel are unnecessary after determination of reflux resolution by voiding cystourethrography.

Ureteral obstruction after dextranomer/hyaluronic acid copolymer injection for treatment of secondary vesicoureteral reflux after renal transplantation

Ureteral obstruction after transurethral injection therapy for primary vesicoureteral reflux is known to occur in less than 1% of cases. We report the first case of a ureteral obstruction after transurethral injection of dextranomer/hyaluronic acid copolymer (Deflux) for the treatment of secondary vesicoureteral reflux after renal transplantation. Loss of transplant function made reimplantation of the ureter necessary. A periureteral phlebitis and moderate foreign body reaction was found histologically, although the patient had received immunosuppressive therapy. Endoscopic therapy of secondary vesicoureteral reflux in patients after renal transplantation is a reasonable minimally invasive treatment option; however, severe complications may occur.

Endoscopic treatment of reflux: management pros and cons

PURPOSE OF REVIEW

The goal of this review is to contrast the issues in favor of and against the use of endoscopic injection therapy in an attempt to highlight the current state of flux and draw attention to areas that merit further research.

RECENT FINDINGS

Current publications have mostly addressed the expanding use of endoscopic injection therapy for vesicoureteral reflux treatment, generally reporting short-term success rates and endpoints. This growing body of literature is presented in the context of perceived benefits vs. disadvantages in comparison with other available treatment modalities.

SUMMARY

The management of vesicoureteral reflux has changed dramatically in the past decade, mostly because of the increasing acceptance of endoscopic injection therapy as an adequate, minimally invasive, and effective form of therapy. Recent advances in the composition of injectable materials have allowed for easier placement with a perceived favorable safety profile. In particular, dextranomer/hyaluronic acid has become the injectable material of choice, with quick acceptance and widespread use soon after its introduction in different countries. As we critically evaluate the evolving treatment options, the presented literature helps draw attention to some of the challenges we face and the need for long-term and carefully planned prospective studies to support our interventions.

Single Center Experience With Endoscopic Management of Vesicoureteral Reflux in Children

PURPOSE

Dx/HA copolymer was approved by the Food and Drug Administration in 2001 for the treatment of VUR in children. Published results have varied widely, prompting us to report our single center experience with 300 consecutive patients.

MATERIALS AND METHODS

All patients undergoing Dx/HA injection (300 children, median age 5.4 years) at our institution were eligible for this study. We examined several parameters to determine which variables influence the success of Dx/HA injection, including preoperative reflux grade, bladder diverticula, neurogenic bladder, ureteral duplication, perioperative urinary tract infection, dysfunctional voiding, laterality of reflux and amount of Dx/HA injected.

RESULTS

A total of 225 patients (75%) underwent postoperative studies, and, thus, were eligible for study inclusion. Reflux was cured in 144 patients (64%) and improved in 44 (20%). A total of 20 patients had ureteral duplication anomalies. Cure rates in this subgroup were significantly decreased compared to nonduplicated cases (40% vs 66%). Injection in low grade (I to II) reflux was significantly more successful than in high grade (III to IV) reflux (72% vs 54%). A total of 10 patients (8.3%) with unilateral reflux had development of de novo contralateral reflux. Of the patients who failed initial injection 10 (4%) underwent repeat injection, of whom 5 (50%) were cured after the second injection. Two patients (0.9%) had development of temporary ureteral obstruction.

CONCLUSIONS

We report a large short-term single center experience with endoscopically injected Dx/HA. Although our cure rate of 64% was less than published rates for open surgery, the minimal morbidity and low complication rate of endoscopic treatment make it an attractive first line therapy for patients with VUR. Longer followup is required to better evaluate this technique.