Prospective study using a new bulking agent for the treatment of vesicoureteral reflux: polyacrylamide hydrogel

Bottom-up engineering of cell-laden hydrogel microfibrous patch for guided tissue regeneration

The development of three-dimensional (3D) fibrous networks as platforms for tissue engineering applications has been attracting considerable attention. Opportunely arranged microscaled fibers offer an appealing biomimetic 3D architecture, with an open porous structure and a high surface-to-volume ratio. The present work describes the development of modified-alginate hydrogel microfibers for cell entrapment, using a purpose-designed flow circuit. For microfibers biofabrication, cells were suspended in gel-precursor alginate solution and injected in a closed-loop circuit with circulating cross-linking solution. The flow promoted stretching and solidification of continuous cell-loaded micro-scaled fibers that were collected in a strainer, assembling into a microfibrous patch. The process was optimized to allow obtaining a self-standing cohesive structure. After characterization of the microfibrous patch, the behavior of embedded human mesenchymal stem cells (hMSCs) was evaluated. Microfibers of oxidized alginate modified with integrin-binding ligands provided a suitable 3D cellular microenvironment, supporting hMSCs survival and stimulating the production of endogenous extracellular matrix proteins, such as fibronectin and collagen Type I. Collectively, these features make the proposed microfibrous structures stand out as promising 3D scaffolds for regenerative medicine.

A review of novel STING bulking agents

OBJECTIVE

The objective of this study was to review the literature to compare the efficacy and complications of polyacrylate-polyalcohol copolymer (PPC) and polyacrylamide hydrogel (PAHG) with the current standard of care, dextranomer/hyaluronic acid (Dx/HA), when used to treat VUR in the paediatric population.

METHODS

PubMed, Embase and Cochrane databases were searched. Keywords included Vesicoureteral reflux (VUR), endoscopic; endoscopic injection, endoscopic treatment, dulking material, dextranomer/hyaluronic acid copolymer, polyacrylate-polyalcohol copolymer, Deflux, Dexell, Vantris, Bulkamid, outcome, treatment and children. Prospective or retrospective studies comparing PAHG/PPC directly with Dx/HA were included for review.

RESULTS

Four studies were identified comparing PPC with Dx/HA. All studies showed superior efficacy (on micturating cystourethrogram (MCUG) at 3 months) of PPC over Dx/HA. However, 1 study identified a significantly higher rate of vesicoureteric junction obstruction (VUJO) in the PPC group. One study was identified comparing PAHG with Dx/HA which showed similar efficacy on 3-month MCUG.

CONCLUSIONS

Current data suggest PPC confers a higher resolution rate of VUR and PAHG confers comparable resolution rates for VUR compared with Dx/HA in the paediatric population. However, the incidence of late-onset VUJO in one study is concerning, and high-quality randomised controlled trials with long-term follow-up are needed before making further recommendations.

Durasphere® EXP: a non-biodegradable agent for treatment of primary Vesico-Ureteral reflux in children

Introduction:

Durasphere^® EXP (DEXP) is a compound of biocompatible and non--biodegradable particles of zirconium oxide covered with pyrolytic carbon. The aim of this study is to evaluate the durability of off-label use of DEXP in the treatment of primary vesicoureteral reflux in children.

Materials and Methods:

Patients who underwent subureteric injection of DEXP for the correction of primary VUR were retrospectively reviewed. Patients aged >18 years as well as those who had grade-I or -V VUR, anatomic abnormalities (duplicated system, hutch diverticulum), neurogenic bladder or treatment refractory voiding dysfunction were excluded. Radiologic success was defined as the resolution of VUR at the 3rd month control. Success was radiographically evaluated at the end of the first year.

Results:

Thirty-eight patients (9 boys, 29 girls; mean age, 6.3±2.7 years) formed the study cohort. Forty-six renal units received DEXP (grade II: 22; grade III: 18; grade IV: 6). Mean volume per ureteric orifice to obtain the mound was 0.70±0.16mL. First con- trol VCUG was done after 3 months in all patients. After the first VCUG, 6 patients had VUR recurrence. Short-term radiologic success of DEXP was 84.2%. Rate of radiologic success at the end of the first year was 69.4% (25/32). Lower age (p:0.006) and lower amount of injected material (p:0.05) were associated with higher success rates at the end of 1 year.

Conclusion:

This is the first study to assess the outcomes of DEXP for treatment of primary VUR in children. After 1 year of follow-up, DEXP had a 69.4% success rate.

Vesicoureteral reflux: From prophylaxis to surgery

Vesicoureteral reflux (VUR) is one of the most common pathologies encountered in pediatric urology. Better understanding of the evolution of VUR and new endoscopic surgical techniques in the last decades have led to major changes in the management of this pathology. However, the treatment algorithm remains complex and is composed of a wide variety of options, from active surveillance to surgical treatment. Herein, we propose to review treatment options for VUR in order to help clinicians make the right treatment decision for the right patient.

Polyacrylamide Hydrogel as a Bulking Agent for the Endoscopic Treatment of Vesicoureteral Reflux: Long-Term Results and Safety

PURPOSE

Polyacrylamide hydrogel has been shown to offer good short-term success for the endoscopic treatment of vesicoureteral reflux. Our objective was to provide long-term results of its efficacy and safety.

MATERIALS AND METHODS

We performed a prospective study using polyacrylamide hydrogel to treat all grades of vesicoureteral reflux. Every patient underwent endoscopic injection of polyacrylamide hydrogel followed by 3-month postoperative renal ultrasound and voiding cystourethrogram. Renal ultrasound was repeated at 12 and 36 months. Treatment success was defined as the absence of de novo or worsening hydronephrosis and the absence of reflux. Safety elements included new or worsening hydronephrosis, calcifications of the injected material and urinary tract infections.

RESULTS

A total of 76 patients (123 refluxing renal units) were assessed. Median age at surgery was 45 months and median followup was 36 months. Median injected volume of hydrogel per refluxing renal unit was 1.0 ml. The overall success rate 3 months after a single injection was 71%. During long-term followup 68 of 70 eligible patients underwent 12-month ultrasound and 40 of 46 underwent 36-month ultrasound. No upper tract deterioration or bulking agent calcifications were reported. Nine (12%) and 2 patients (3%) presented with nonfebrile and febrile urinary tract infections, respectively.

CONCLUSIONS

The success rate of polyacrylamide hydrogel for endoscopic treatment of vesicoureteral reflux is comparable to published results of dextranomer hyaluronic acid. The long-term safety data and potential lower cost of polyacrylamide hydrogel provide further support for the use of this nonparticulate bulking agent to treat reflux.

Durability, safety and efficacy of polyacrylamide hydrogel (Bulkamid(®)) in the management of stress and mixed urinary incontinence: three year follow up outcomes

Introduction

There are a myriad of treatment options available for patients suffering with the increasingly prevalent condition of stress urinary incontinence (SUI). The minimally invasive nature of periurethral bulking agents makes them an attractive proposition in the correctly selected patient. There is, however, limited data available on the medium to long term safety and efficacy of this procedure. The aim of our study is to evaluate the outcomes of Polyacrylamide Hydrogel (PAHG) (Bulkamid^®) as a periurethral bulking agent at our institution.

Material and methods

From 2006 to 2011, two hundred and fifty six women underwent periurethral bulking with PAHG in the management of SUI or mixed urinary incontinence (MUI). Women were assessed with at least yearly quality of life and ICIQ questionnaires.

Results

The majority of patients had the procedure under a local anaesthetic, with a median operative time of 9 minutes. Median follow up was 38 months. 82% of patients reported cure/significant improvement at 3 months. Importantly, this high satisfaction rate was maintained at final follow up and was reflected in both VAS and ICIQ scores. There were no reported adverse reactions and no significant safety concerns.

Conclusions

We conclude that Bulkamid^® injection is an efficacious, minimally invasive, and safe procedure for a selected group of patients with stress incontinence. In our study, PAHG has been shown to be durable and safe.

Efficacy of dextranomer hyaluronic acid and polyacrylamide hydrogel in endoscopic treatment of vesicoureteral reflux: A comparative study

INTRODUCTION

Various bulking agents are available for vesicoureteral reflux (VUR) endoscopic treatment, but their inconsistent success rates and costs are concerns for urologists. Recently, polyacrylamide hydrogel (PAHG) has been shown to have a good overall success rate, which seems comparable to dextranomer hyaluronic acid (Dx/HA), currently the most popular bulking agent. Our objective was to compare the short-term success rate of PAHG and Dx/HA for VUR endoscopic treatment in children.

METHODS

We performed a prospective non-randomized study using PAHG and Dx/HA to treat VUR grades I to IV in pediatric patients. All patients underwent endoscopic sub-ureteric injection of PAHG or Dx/HA, using the double-HIT technique, followed by a 3-month postoperative renal ultrasound and voiding cystourethrogram. Treatment success was defined as the absence of de novo or worsening hydronephrosis and absence of VUR.

RESULTS

A total of 90 pediatric patients underwent an endoscopic injection: 45 patients (78 ureters) with PAHG and 45 patients (71 ureters) with Dx/HA. The mean injected volume of PAHG and Dx/HA was 1.1 mL and 1.0 mL, respectively. The overall success rate 3 months after a single treatment was 73.1% for PAHG and 77.5% for Dx/HA. Postoperatively, 1 patient in each group presented with acute pyelonephritis and 2 patients in the Dx/HA group developed symptomatic ureteral obstruction.

CONCLUSION

Success rates of PAGH and Dx/HA in endoscopic injections for VUR treatment were comparable. The rate of resolution obtained with Dx/HA was equivalent to those previously published. The lower cost of PAHG makes it an interesting option.