Endoscopic injection therapy

Efficacy of Three Different Injection Techniques for the Endoscopic Treatment of Vesicoureteral Reflux (VUR) in Children: A Review of 10 Years of Experience

Aim

To review our 10 years of experience with the endoscopic treatment of vesicoureteral reflux (VUR) in children, emphasizing the long-term efficacy of the "combined STING-HIT" technique.

Materials and Methods

A retrospective study was performed including all children with symptomatic VUR undergoing the cystoscopic injection of bulking agents from January 2013 to December 2022 in our pediatric tertiary referral center. Three different endoscopic techniques were adopted: the "combined STING-HIT" technique, the STING technique, and the HIT technique. Treatment success was defined as symptom remission and VUR resolution on the voiding cystourethrogram (VCUG) performed at the 3-month follow-up.

Results

In the study period, 140 (F:M = 64:76) patients and 228 ureters were treated at a median patient age of 3 (2.0-6.0) years. After a single endoscopic treatment, VUR resolved in 203 (88%) ureters. The VUR resolution rate after a single endoscopic treatment was 95% (n=70/74) in case of I-II VUR, 88% (n=87/99) in case of III VUR; 83% (n=38/46) in case of IV VUR; 89% (n=8/9) in case of V VUR (p-value: 0.174). Overall, one or two endoscopic treatments succeeded in 219 (96%) ureters. The overall VUR resolution rate following one or two endoscopic treatments was 100% (74/74) in case of I-II VUR, 93% (n=92/99) in case of III VUR; 96% (n=44/46) in case of IV VUR; 100% (n=9/9) in case of V VUR (p-value: 0.083). Despite not being statistically significant, the VUR resolution rate was higher for the "combined STING-HIT" technique, both after one (92%: n=110/119; versus 85%; n=62/73 versus 86%; n=31/36; p-value: 0.225) or two (98%: n=116/119; versus 95%; n=69/73 versus 94%; n=34/36; p-value: 0.469) endoscopic treatments.

Conclusion

The endoscopic approaches were highly successful for the treatment of VUR in children. The "combined STING-HIT" technique was a safe and effective procedure, being associated with the higher resolution rate.

Therapeutic Management of Children with Vesicoureteral Reflux

Contrasting data refer to therapies for vesicoureteral reflux (VUR), such as surgical treatments and continuous antibiotic prophylaxis (CAP). This study evaluated the effectiveness of these approaches in children with VUR, analyzing the recurrence of febrile urinary tract infections (UTIs) and the resolution of VUR after the treatment. A total of 350 pediatric patients underwent contrast-enhanced voiding urosonography (ceVUS) to diagnose a VUR, whereas renal scintigraphy evaluated potential scars. After 12 months from the treatment, the VUR, the relapse of febrile UTIs, and reflux-related nephropathy were analyzed. Twenty-seven children had recurrent febrile UTIs after surgical therapy, with a greater rate of relapses observed in III and V VUR grades. Thirteen patients who underwent surgery had scars, independently of VUR grades and gender, with evidence of chronic renal failure at the end of the follow-up period. A total of 140 subjects were treated with CAP, and 30% of them continued to suffer from febrile UTIs. Ninety-five patients with VUR underwent ceVUS after 12 months, with persistent reflux in fifty-two patients. All of them had severe VUR, correlating with the age at diagnosis and gender. CAP therapy prevented scarring better than surgery, especially in children with III and V grades of VUR. A late onset of VUR or VUR involving neonatal patients is rarely a reversible process. This study identified predictors of success or failure of surgical or CAP therapies, evaluating the relapse of UTIs or persistent reflux after the treatment and giving prognostic information in children with VUR.

Efficacy and safety of Hyadex for treatment of vesicoureteral reflux: a multicenter experience

OBJECTIVE

This study was performed to evaluate the efficacy and safety of dextranomer/cross-linked hyaluronic acid (Hyadex) in patients with a clinical diagnosis of vesicoureteral reflux (VUR).

METHODS

In this cross-sectional multicenter observational study, Hyadex was used in four different centers for the endoscopic treatment of VUR from 2020 to 2022. The study involved 74 patients (93 renal units) who were diagnosed with VUR according to voiding cystourethrography (VCUG) findings and were considered suitable for subureteric endoscopic treatment. The follow-up time (control VCUG time) was 3 months.

RESULTS

In the VCUG evaluation, grade I VUR was found in 13 renal units, grade II in 23 renal units, grade III in 42 renal units, and grade IV in 12 renal units. The success rates of Hyadex treatment according to the degree of VUR were as follows: 84.6% for grade I, 82.6% for grade II, 71.4% for grade III, and 66.0% for grade IV. No major complications were observed.

CONCLUSION

Endoscopic subureteric Hyadex injection had high success rates in appropriately selected patients with VUR and may be used as the first-line treatment for children with VUR.

Endoscopic injection of bulking agents in pediatric vesicoureteral reflux: a narrative review of the literature

In the last 20 years, endoscopic injection (EI) has affirmed as a valid alternative to open surgery for management of pediatric vesicoureteral reflux (VUR). This study aimed to investigate and discuss some debated aspects such as indications, bulking agents and comparison, techniques of injection and comparison, predictive factors of success, use in specific situations. EI is minimally invasive, well accepted by patients and families, with short learning curve and low-morbidity profile. It provides reflux resolution rates approaching those of open reimplantation, ranging from 69 to 100%. Obviously, the success rate may be influenced by several factors. Recently, it is adopted as first-line therapy also in high grade reflux or complex anatomy such as duplex, bladder diverticula, ectopic ureters. The two most used materials for injection are Deflux and Vantris. The first is absorbable, easier to inject, has lower risk of obstruction, but can lose efficacy over time. The second is non-absorbable, more difficult to inject, has higher risk of obstruction, but it is potentially more durable. The two main techniques are STING and HIT. To date, the ideal material and technique of injection has not yet clearly established, but the choice remains dependent on surgeon's preference and experience.

Magnetic Agarose Microspheres/Hyaluronic Acid Hydrogel as a Trackable Bulking Agent for Vesicoureteral Reflux Treatment

Vesicoureteral reflux (VUR) is one of the most common congenital anomalies in the kidney and the urinary tract. Endoscopic subureteral injection of a bulking agent has become popular in VUR treatment due to its high success rates, few complications, and a straightforward procedure. In this study, a novel magnetic bulking agent was prepared by embedding Fe₃O₄ magnetic nanoparticles in cross-linked agarose microspheres with diameters of 80–250 μm and dispersing the magnetic microspheres in a hyaluronic acid hydrogel. The bulking agent has good biocompatibility and biosecurity validated by the tests of cytotoxicity, in vitro genotoxicity, animal irritation, skin sensitization, acute systemic toxicity, and pathological analysis after the injection of the bulking agent extract solution into healthy mice as well as injection of the bulking agent into VUR rabbits. The VUR rabbits were created by incising the roof of the intravesical ureter to enlarge the ureteral orifice. The success rate of the bulking agent in treating VUR rabbits using a subureteral transurethral injection technique was 67% (4/6) or 80% (4/5, excluding the unfinished rabbit), and no migrated particles were found in the organs of the rabbits. The transverse relaxation rate of the bulking agent was 104 mM⁻¹s⁻¹. After injection, the bulking agent was long-term trackable through magnetic resonance imaging that can help clinicians to inspect the VUR treatment effect. For the first time, this study demonstrates that the bulking agent with a long-term stable tracer is promising for endoscopic VUR treatment.

Advantages of Hyaluronic Acid and Its Combination with Other Bioactive Ingredients in Cosmeceuticals

This study proposes a review on hyaluronic acid (HA) known as hyaluronan or hyaluronate and its derivates and their application in cosmetic formulations. HA is a glycosaminoglycan constituted from two disaccharides (N-acetylglucosamine and D-glucuronic acid), isolated initially from the vitreous humour of the eye, and subsequently discovered in different tissues or fluids (especially in the articular cartilage and the synovial fluid). It is ubiquitous in vertebrates, including humans, and it is involved in diverse biological processes, such as cell differentiation, embryological development, inflammation, wound healing, etc. HA has many qualities that recommend it over other substances used in skin regeneration, with moisturizing and anti-ageing effects. HA molecular weight influences its penetration into the skin and its biological activity. Considering that, nowadays, hyaluronic acid has a wide use and a multitude of applications (in ophthalmology, arthrology, pneumology, rhinology, aesthetic medicine, oncology, nutrition, and cosmetics), the present study describes the main aspects related to its use in cosmetology. The biological effect of HA on the skin level and its potential adverse effects are discussed. Some available cosmetic products containing HA have been identified from the brand portfolio of most known manufacturers and their composition was evaluated. Further, additional biological effects due to the other active ingredients (plant extracts, vitamins, amino acids, peptides, proteins, saccharides, probiotics, etc.) are presented, as well as a description of their possible toxic effects.

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.

Brazilian consensus on vesicoureteral reflux-recommendations for clinical practice

Introduction

Vesicoureteral Reflux (VUR) is characterized by a retrograde flow of urine from the bladder into the ureters and kidneys. It is one of the most common urinary tract anomalies and the major cause of urinary tract infection (UTI) in the first years of life. If not properly diagnosed and treated can lead to recurrent UTI, renal scar and, in severe cases, to end stage renal disease. Despite recent advances in scientific and technological knowledge, evaluation and treatment of VUR is still controversial and there is still considerable heterogeneity in evaluation methods and therapeutic approaches. The aim of the present consensus is to give a practical orientation on how to evaluate and treat VUR.

Methods

The board of Pediatric Urology of the Brazilian Society of Urology joined a group of experts and reviewed all important issues on Vesicoureteral Reflux evaluation and treatment and elaborated a draft of the document. On November 2017 the panel met to review, discuss and write a consensus document.

Results and Discussion

Vesicoureteral Reflux is a common and challenging problem in children. Children presenting with Vesicoureteral Reflux require careful evaluation and treatment to avoid future urinary tract infections and kidney scars. The panel addressed recommendations on up to date choice of diagnosis evaluation and therapies.

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

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

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.