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The Changing Concepts in Vesicoureteric Reflux in Children

S. Tekgul, F. Canakli
Ankara, Turkey

 

Correspondence

Serdar Tekgul M.D., FEAPU.
Hacettepe University, Department of Urology,
Division of Pediatric Urology,

Ankara, Turkey, 06100

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Introduction

The management of vesicoureteral reflux in children is one of the most controversial issues in pediatric urology. Recent advances on the understanding of bladder dynamics and the natural course of reflux and introduction of minimally invasive treatment options have evolved the management dramatically. This paper will review the role of bladder dynamics and advances in endoscopic treatment of reflux.

Role of bladder dynamics on reflux

Over the last 2-3 decades, evolution of new concepts in bladder physiology has made the urologists investigate and treat the disorders of the lower urinary tract from a functional, rather than a structural standpoint. Initially vesico-ureteric reflux is considered to be mainly due to structural abnormality of the uretero-trigonal complex. However the observation that high intravesical pressures occur during dysfunctional voiding has led the speculation that vesico-ureteral reflux could develop in dysfunctional voiding without any overt neurological disease. This is actually analogous to the occurrence of reflux in high-pressure neurogenic bladders.

When reflux was first discovered it was believed that the surgical correction was the way of treating the problem and its complications. Yet with multicenter trials, we have come to an understanding that the reflux can be managed conservatively and many refluxing patients may show spontaneous resolution. It is quite evident now that not only congenitally abnormal implantation of ureter into the bladder, but also urinary tract infections, bladder and urethral dysfunction and ureteric peristaltic properties play a significant role in the etiology of reflux.

In simple terms dysfunctional voiding is the result of voluntary contractions of the external sphincter by the child in an attempt to stop leakage of urine by involuntary contractions of the detrussor. This often causes higher intravesical pressures both during storage and voiding. High intravesical pressures may cause reflux of urine especially during voiding when the intravesical pressures are the highest. Yet, not all the dysfunctional voiders will develop reflux despite very high intravesical pressures. If voiding dysfunction does cause reflux it probably occurs by compromise of a borderline uretero-trigonal structure.

Role of bladder function on the outcome of reflux is significant starting from the first year of life(1). In the youngest infants abnormal bladder function can be present at birth, whereas in older children it may be acquired and learned during the toilet training years, if it is not already present. In a study by Sillen on infants with gross bilateral reflux, extreme detrussor over activity without signs of intravesical obstruction was found in boys(2). Infant girls with gross bilateral reflux did not show the same degree of detrussor over activity. Other studies assessing severe reflux in newborns high rate of spontaneous resolution of reflux during infancy was a common finding(3). Studies have also shown that resolution of reflux in the infant correlated with the normalizing of bladder functions with aging(3,4). If urinary tract infection and reflux is mainly due to dysfunctional voiding, the correction of dysfunction usually helps the reflux and infections to stop. The prognosis of reflux may be dictated by both severity of voiding dysfunction and structural abnormality. If reflux still continues despite resolution of voiding dysfunction, anti-reflux surgery may be indicated to correct the structural abnormality.

Endoscopic treatment

Figure. 1: The needle is inserted a few millimeters distal to the
orifice, and advanced into position just under the ureter. Injection
should produce a mound of implant material that elevates the
ureteral orifice and causes it to assume a crescent shape.
changing concepts

Since the first urological use of the endoscopic injection technique with polytef (PTFE) by Matouchek in 1981, endoscopic subureteric injection procedure (STING) has become a popular treatment modality for the treatment of vesico-ureteral reflux (VUR) in children. Initially Puri and O’Donnel popularized the technique using polytef paste (Teflon®) and reported very encouraging results. Later, concerns about the risk of migration and malignancy have led to the development of other injectables like collagen (Contigen®) and silicon particles (Macroplastique®). More recently micro spheres of dextranomer particles in sodium hyaluranon solution (Deflux®) have been introduced with good results. Dextranomer/hyaluronic acid copolymer has been studied primarily in Europe, where it was used first. It has results that are comparable to Teflon and Macroplastique. Deflux is currently the only FDA approved injectable for the treatment of reflux in the United States. Owing to its pseudo plastic properties Deflux is easily handled and injected with less force on the syringe. This helps to place the bulge into subureteric area properly. There are more different injectables including autologous substances under investigation for the endoscopic treatment of reflux but all lack sufficient experimental and clinical data. 

Over the last 2 decades STING procedure has certainly proved to be a good treatment alternative for patients with VUR(5). It has an overall success rate of about 75% for the renal unit. It has better results with low grades of reflux. The success rate increases up to 85% with more than one injection to the same ureter(6). STING is as successful in primary reflux as in reflux secondary to voiding dysfunction(7). The only exception is that the results are poorer in reflux due to neurogenic voiding dysfunction. STING is also a reasonable option in the management of complex cases of VUR before resorting to more difficult surgical procedures.8 Although its success rate may be lower when compared to open surgery, the advantages of this technique cannot be overlooked, it is simple, it has low morbidity and it can be done as an outpatient procedure. See the illustration for the standard technique of injection. (Fig. 1) Recently, several technical modifications are reported to have improved success results(9).

A newer approach is to use this treatment modality as an alternative to medical treatment. Although there are not yet well established prospective controlled trials with long term outcome, in some centers around Europe STING is being advised as the initial treatment of choice to treat reflux. This new approach recommends that most children with persistent VUR (longer than 1 year) be offered endoscopic treatment as an alternative to prolonged antibiotic prophylaxis or open surgery.5 Future studies investigating the incidence of UTI and scar formation will be needed to clarify the use of STING procedure as an alternative treatment to medical therapy(10).

 

 

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