A review of novel STING bulking agents

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

Long-term outcome of randomized clinical trial between polyacrylate-polyalcohol copolymer (PPC) and dextranomer-hyaluronic acid copolymer (Dx/HA) as bulking agents for endoscopic treatment of primary vesicoureteral reflux (VUR)

OBJECTIVE

The aim of our study is to compare long-term outcome of endoscopic treatment of VUR using PPC or Dx/HA.

PATIENTS AND METHODS

From October 2014 to April 2017 patients with VUR grades from 3 to 5 that needed endoscopic treatment were eligible for this RCT. Patients were randomized in two groups: PPC and Dx/HA. A VCUG was performed at 6 months; if VUR > 3 was still present a second ET was performed. We included for this long-term follow-up study those patients that were successfully treated at short-term follow-up. At 36 months postoperative VCUG was performed to assess outcome. Success was considered if postoperative VUR grade was 0 at 36 months, and there was no ureteral obstruction.

RESULTS

In the previous study, 60/73 ureters were successfully treated in 36/44 patients, and then we have analyzed 60 ureters in 36 patients. Three patients were lost in long-term follow-up, and then we analyzed 57 ureters in 33 patients divided. PPC group 18 patients (28 ureters); and Dx/HA group 15 patients (29 ureters). After 3 years of follow-up the VCUG showed a success rate of 26/28 of RU in PPC and 26/29 of DX/HA. Two RU in PPC group had ureteral obstruction, and then the successful rate for PPC group dropped to 24/28. The overall successful rate at long-term was 72.7% of the RU in PPC group and 70.3% in Dx/HA group.

CONCLUSION

PPC and Dx/HA has similar long-term outcome in VUR resolution, but ureteral obstruction could be present at long-term follow-up in PPC group.

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.

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.

A systematic review & meta-analysis comparing outcomes of endoscopic treatment of primary vesico ureteric reflux in children with polyacrylate poly alcohol copolymer versus dextranomer hyaluranic acid

BACKGROUND & AIMS

There are conflicting reports on the efficacy of bulking agents for vesico ureteric reflux (VUR). In this meta-analysis we have compared the outcomes of endoscopic treatment with polyacrylate polyalcohol copolymer (PPC) and dextranomer hyaluronic acid (DxHA).

METHODS

A systematic review of publications between 2010 and 2020 was conducted covering databases like PUBMED, MEDLINE etc. for (endoscopic treatment) AND (VUR) AND (PPC OR DxHA) AND (recurrence OR complications). PRISMA guidelines were followed and only comparative studies were included. Outcomes were early success defined as absence of VUR in voiding cystourethrogram at 3-months followup, urinary tract infections (UTI) and occurrence of vesico-ureteric-junction obstruction (VUJO). Risk of bias was analysed with Robvis tool and odds-ratios were compared with Revman-3.0.

RESULTS

Among nine studies (heterogeneity; I 2 69-79%) all cleared the risk of bias assessment. There was no significant difference in high grade VUR (p = 0.94) between PPC (40%) and DxHA (43%). Success rate after single injection was significantly higher (p = 0.0001) at 86% (477/555) for PPC vs 69% (474/685) for DxHA. UTI rate between PPC (12%) and DxHA (14.6%) was not statistically significant (p = 0.54). VUJO rate between PPC (3.9%) and DxHA (0.8%) was also not significantly different (p = 0.47). Significantly lesser volume (p = 0.02) was used for PPC (0.7 ml) compared to DxHA (0.9 ml).

CONCLUSION

Reflux resolution was significantly higher with PPC than DxHA. Postinjection UTI/VUJO incidence was not significantly different between them. Limitation of this meta-analysis was heterogeneity & small number of articles. Further studies should focus on long-term outcomes and cost-effectiveness.

Comparison of polyacrylate polyalcohol copolymer (PPC) and dextranomer/hyaluronic acid (Dx/HA) for treatment of vesicoureteral reflux. A systematic review and meta-analysis

PURPOSE

Our study aimed to compare the efficacy of polyacrylate polyalcohol copolymer and Dextranomer-Hyaluronic Acid for endoscopic treatment of vesicoureteral reflux.

MATERIAL AND METHODS

MEDLINE, EMBASE, Scopus, Web of science, Ovid, Cochrane databases, Google scholar have been searched for studies published until January 2022 in any language. Studies that compared the success rate for endoscopic treatment of vesicoureteral reflux in children with two bulking agents, namely, "polyacrylate polyalcohol copolymer." and "Dextranomer-Hyaluronic Acid" were included for this analysis.

RESULTS

Nine studies were included in data synthesis for this meta-analysis. Pooled data with a total of 763 ureters in PPC group and 718 ureters in Dx/HA group indicated that ureters in PPC group were more likely to undergo complete reflux resolution than Dx/HA (OR 3.80, 95% CI: 2.71; 5.31). Among subgroup of patients with high grade reflux, PPC injection had more resolution rate compared to Dx/HA patients (OR: 2.92, 95% CI: 1.19-7.16). In total, 95.81% of the PPC group and 86.52% of the Dx/HA group experienced success after the third injection. However a concerning complication of endoscopic treatment which is ureterovesical junction obstruction (UVJO) was more prevalent in PPC group. So the possible benefits arising from endoscopic treatment with PPC could be offset by the costs of re-implantation surgery or stenting in the case of UVJO.

CONCLUSION

These data indicate that PPC injection for vesicoureteral reflux treatment was associated with a higher success rate, but concerningly, UVJO incidence was higher in the PPC group which might negate the possible benefits of PPC injection However, due to the lack of studies with long-term follow-up, we couldn't reach a definitive conclusion about the superiority of one of the bulking agents over the other.

Management of Vesicoureteral Reflux: What Have We Learned Over the Last 20 Years?

Vesicoureteral reflux (VUR) is associated with increased risks of urinary tract infection, renal scarring and reflux nephropathy. We review advancements over the last two decades in our understanding and management of VUR. Over time, the condition may resolve spontaneously but it can persist for many years and bladder/bowel dysfunction is often involved. Some factors that increase the likelihood of persistence (e.g., high grade) also increase the risk of renal scarring. Voiding cystourethrography (VCUG) is generally considered the definitive method for diagnosing VUR, and helpful in determining the need for treatment. However, this procedure causes distress and radiation exposure. Therefore, strategies to reduce clinicians' reliance upon VCUG (e.g., after a VUR treatment procedure) have been developed. There are several options for managing patients with VUR. Observation is suitable only for patients at low risk of renal injury. Antibiotic prophylaxis can reduce the incidence of UTIs, but drawbacks such as antibiotic resistance and incomplete adherence mean that this option is not viable for long-term use. Long-term studies of endoscopic injection have helped us understand factors influencing use and the effectiveness of this procedure. Ureteral reimplantation is still performed commonly, and robot-assisted laparoscopic methods are gaining popularity. Over the last 20 years, there has been a shift toward more conservative management of VUR with an individualized, risk-based approach. For continued treatment improvement, better identification of children at risk of renal scarring, robust evidence regarding the available interventions, and an improved VUR grading system are needed.

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.

A rare and unusual complication of the STING procedure

An 8-year-old boy underwent a STING procedure for vesicoureteric reflux. 11 years later, at 19-years-old he presented with the passage of sediment per urethra every 7 weeks. CT scan demonstrated a lesion at the right VUJ. Cystoscopy revealed a 2cm suburothelial mass adjacent to the VUJ, with normal urothelium overlying it. Resection of the area revealed a white plastic-like substance, consistent with the bulking agent Deflux, which was scraped away. The patient made an uneventful recovery and at review, 3 months later, is symptom free. Our case demonstrates a rare and unusual complication of the STING procedure.

Section headings

Endourology, General Urology, Paediatrics.

Risk factors for obstructive complications after endoscopic correction of vesico-ureteral reflux using polyacrylate polyalcohol copolymer

Use of polyacrylate-polyalcohol copolymer (PPC) after endoscopic correction (EC) of vesico-ureteral reflux (VUR) is highly effective but is associated with a higher risk of obstructive complications (OC) compared with other implants. We undertook a STROBE compliant retrospective investigation and studied the OC risk factors to increase the practical safety of PPC.Overall, 798 patients (464 [58.1%] girls and 334 [41.9%]) boys) from 5 hospitals in whom PPC was routinely used were evaluated retrospectively. The patients were subdivided into 2 groups. Group I consisted of 754 (94.5%) children (449 [59.5%] girls and 305 [40.5%] boys) without OC. Median age was 41 months [Q1: 18.0; Q3: 81.0]. Group II comprised 44 (5.5%) patients (29 [65.9%] boys and 15 [34.1%] girls) experiencing OC, and their median age was 21.5 months [Q1: 12.0; Q3: 43.0]. Clinical and renal ultrasound examinations were carried out 1 day and 1 month after EC, and then every 6 months after EC. At the follow-up examination approximately 6 months after EC, voiding cysto-urethrography (VCUG) was performed. All patients with OC underwent diuretic renography.OC occurred in 44 (5.5%) of 798 children, in some cases as late as 60 months after endoscopic injection of the bulking agent PPC for correction of VUR. Univariate analysis revealed that younger age (P < .001), higher grade of VUR (P < .001), male gender (P < .001), second injection (P = .003), and EC injection using hydrodistension implantation technique (HIT; P < .001) represented significant risk factors. At multivariate analysis, only male gender (P = .0078), younger age (P = .0044), HIT technique (P < .0001), and second injection (P = .04) represented significant risk factors for the occurrence of OC.We identified young age, male gender, high reflux grade, HIT technique, and second endoscopic injections as factors associated with the risk of OC after EC of VUR using PPC as a bulking agent. Thus, patients who have undergone EC with PPC must be monitored sonographically for occurrence of OC for at least 60 months after the intervention.