Delayed-onset Ureteral Obstruction and Calcification Masquerading as Renal Colic Following Deflux Injection

The color Doppler twinkling artifact of implants after endoscopic treatment of vesicoureteral reflux in children: A common finding with high potential for misdiagnosis

BACKGROUND

Endoscopic treatment of vesicoureteral reflux (VUR) is a common therapeutic procedure in children. Over the last years several studies reported on calcified deflux implants that were misinterpreted as ureteral stones leading to unnecessary diagnostic and therapeutic procedures.

OBJECTIVE

Based on an own case, where a calcified implant with a strong twinkling artifact was misdiagnosed as a ureteral stone, the purpose of our study was to evaluate the sonographic imaging appearance of implants after endoscopic VUR repair with special emphasis on the color twinkling artifact.

MATERIAL AND METHODS

In 40 children (mean age 9.5 years) with 62 treated ureteral units follow-up sonography was performed after a mean time interval of 48.8 months after surgery. The injected deposit was evaluated with B-mode sonography and color Doppler sonography and deposit volume, posterior acoustic shadowing and the appearance and extension of the twinkling artifact were evaluated.

RESULTS

47 of 62 injected units (75.8%) could be identified on follow-up sonography. In 13 of 47 units (27.7%) posterior acoustic shadowing was noted. On color Doppler sonography a twinkling artifact appeared in 26 of the 47 visible cases (55.3%). There was a statistically significant correlation between a positive twinkling sign and the deposit age.

CONCLUSION

In conclusion our study shows that the twinkling artifact is a common finding in follow-up sonography of children after endoscopic treatment of VUR. As the twinkling artifact is a sensitive imaging sign for the detection of ureteral calculi the risk of misinterpretation and mistreatment is given.

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.

The effect of prior endoscopic correction of vesicoureteral reflux on open ureteral reimplantation: Surgical outcomes and costs

INTRODUCTION

Endoscopic injection of a bulking agent is a common first-line approach to the treatment of vesicoureteral reflux (VUR). While early outcomes are comparable to open ureteroneocystotomy, 5-25% of children will eventually develop recurrent reflux necessitating repeat injections or open ureteral reimplantation.

OBJECTIVE

To determine whether prior endoscopic injection of a bulking agent impacts outcomes of subsequent open ureteral reimplantation.

STUDY DESIGN

Using a retrospective cohort design, radiographic and clinical outcomes of open ureteral reimplantation were compared between patients with and without prior endoscopic correction of reflux. Surgical and hospitalization data were also compared between groups and a cost comparison was performed to assess differences in healthcare costs between the two cohorts. Units of analysis included total ureters or total patients. For certain variables, subanalysis of unilateral versus bilateral reimplantation was included.

RESULTS

A total of 258 patients underwent open reimplantation for VUR between 2007 and 2016 by five pediatric urologists. Final analysis (see Summary Table) included 192 patients with pre-operative and postoperative voiding cystourethrogram (VCUG) and follow-up data at a median 4.95 months. Among 317 reimplanted refluxing ureters, radiographic resolution was reached in 26/27 (96.3%) patients with and 279/290 (96.2%) without prior endoscopic treatment (P = 0.981). Clinical success was achieved in 17/17 (100%) patients with and 174/175 (99.4%) without prior endoscopic treatment (P = 0.755). There were no statistically significant differences between duration of surgery or length of hospital stay. There were no statistically significant differences between total charges, total costs, and operating room (OR) costs between groups.

DISCUSSION

This study indicated that prior endoscopic injection of a bulking agent did not impact the outcomes or costs of subsequent open ureteroneocystotomy. While prior studies have demonstrated tissue changes associated with injection of a bulking agent, these did not seem to significantly impact the difficulty of later open surgery or the success rates compared to patients who proceeded directly to open correction of reflux.

CONCLUSION

Open ureteral reimplantation for recurrent VUR after failed endoscopic injection of a bulking agent was safe and effective, with comparable outcomes and costs to open surgery in patients without prior endoscopic correction.

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.