Recurrent urinary tract infections (UTI) are a frequent problem especially in young females: nearly 1 in 3 women will have had at least one episode of UTI by the age of 24 years. Febrile UTIs in combination with vesicoureteral reflux (VUR) can cause renal scarring, contrary than previously assumed even in older patients, which may lead to potentially serious consequences such as hypertension and renal failure later in life.
Nevertheless, there is still a lack of literature and controversy over evaluation, prophylaxis, and therapy of recurrent febrile UTIs in young women exists.
In infants who suffer from febrile urinary tract infections, the incidence of vesicoureteral reflux (VUR) according to standard voiding cystourethrography accounts up to 50% whereas the incidence in young females appears to be much lower (2,3%). This may be due to the maturation of bladder function in adolescents and the resulting low sensitivity of conventional VCUG for detecting VUR in older female children, female adolescents and young women.
It could be shown that a high percentage of women with recurrent febrile UTIs and negative conventional VCUG suffers from so-called occult VUR which was detected by performing a cystography with the positioning of the instillation of contrast at the ureteral orifice (PIC cystography).
We aimed to evaluate the clinical outcome of 24 young females after treatment of occult VUR by endoscopic injection of a bulking agent (dextranomer/hyaluronic acid copolymer) in an intraureteric position (HIT procedure). Occult VUR was assumed after recurrent febrile UTIs (more than 3 per year) in combination with renal scarring on 99mTc-2,3-dimercaptosuccinic acid (DMSA) scan in patients with negative standard VCUG.
An overall success rate of endoscopic treatment, which was defined as the absence of postoperative febrile UTIs, of 95,8% could be shown.
Whereas in infants with recurrent febrile UTIs the exclusion of VUR is thought to be mandatory, the current EAU guidelines do no recommend routine imaging of the upper urinary tract and cystoscopy in recurrent uncomplicated UTIs in adult women.
In our study, all patients showed refluxive ureteral orifices corresponding to the side of the affected kidney on DMSA scan. Therefore occult VUR could be confirmed in all patients with recurrent febrile UTIs, positive DMSA scan and negative VCUG.
In summary, the following conclusions can be made:
The presence of renal scarring on DMSA scan may be used as a predictor in selecting female patients with recurrent febrile UTIs. The most probable aetiology of recurrent febrile UTIs in these patients seems to be occult VUR.
Dysfunctional voiding was found in half of the patients taking part in our study. Although they all received treatment by pelvic floor therapy and behavioural interventions before performing cystoscopy recurrent febrile UTIs remained. All patients of our cohort showed refluxive ureteral orifices on cystoscopy. PIC cystography was not performed and is not necessarily required for the correct diagnosis of occult VUR. Recurrent febrile UTIs in combination with a positive DMSA scan may be a sufficient indication for endoscopic treatment of VUR.
Endoscopic injection of bulking agents seems to be an appropriate therapy for occult VUR in young females. Besides being a minimally invasive option, it shows similarly high success rates as ureteral reimplantation in primary VUR and significantly reduces the incidence of febrile UTIs. We consider it important to diagnose and treat occult VUR in order to avoid excessive use of antibiotics and to prevent further renal scarring and possibly severe sequels.
Written By: J Roesch, MD. and J Oswald, FEAPU, Department for Pediatric Urology, Hospital of the Sisters of Charity, Linz, Austria