Commentary: vesicoureteral reflux--1992

Bladder dynamics and vesicoureteral reflux: factors associated with idiopathic lower urinary tract dysfunction in children

PURPOSE

The objective of this study was to determine the clinical, demographic, urodynamic and prognostic characteristics related to vesicoureteral reflux among patients with idiopathic lower urinary tract dysfunction.

MATERIALS AND METHODS

We retrospectively reviewed the records of 348 children with idiopathic detrusor overactivity or dysfunctional voiding who had been examined for vesicoureteral reflux between 1995 and 2005 at a university hospital. Demographic, clinical and urodynamic parameters were compared between groups according to the presence, grade, laterality and resolution of vesicoureteral reflux.

RESULTS

Among the 348 patients 8 infants were excluded from statistical analysis and are discussed separately. Among the 340 remaining patients 1 year and older vesicoureteral reflux was documented in 155 (46%), of whom 32% had bilateral reflux. Of the overall cases 60% were grade III or higher. Mean age in the refluxing group (6.5 +/- 2.8 years) was significantly lower than in the nonrefluxing group (7.6 +/- 2.5 years, p <0.001). Continent children presented with a significantly higher rate of vesicoureteral reflux compared to incontinent children (74% vs 42%, p <0.001). Among the patients who had urinary tract infection the presence of reflux increased the rate of renal cortical abnormalities (45% vs 17%, p <0.001). However, among patients who were free of urinary tract infection the presence of reflux was not associated with cortical abnormalities (25% vs 24%, p >0.05). Median maximum filling pressure was higher in the refluxing group compared to the nonrefluxing group (40.0 vs 34.0 cm H(2)O, p <0.001). Detrusor overactivity and dysfunctional voiding showed similar rates for development of vesicoureteral reflux. Reflux was resolved with medical treatment in 40% of the patients. The resolution rate was significantly higher in children with nondilating reflux and initial lower median cystometric bladder capacity.

CONCLUSIONS

Vesicoureteral reflux is associated with daytime incontinence, urinary tract infection, younger age and renal cortical abnormalities among patients with idiopathic lower urinary tract dysfunction. Increased intravesical pressures seem to be the primary factor for inducing reflux in idiopathic lower urinary tract dysfunction. Initial bladder capacity predicts the resolution of reflux.

Management of pyelonephritis and upper urinary tract infections

The most frequent cause of upper urinary tract infection remains E. coli. Other organisms are found in complicated infections associated with diabetes mellitus, instrumentation, stone, and immunosuppression. The pathogenesis of acute pyelonephritis is reviewed herein, with an emphasis on the virulence factors responsible for its initiation, including urothelial adhesion by P-fimbriae of E. coli and other common factors including hemolysin and aerobactin. Renal damage does not always ensue following such infection. It is seen when toxic oxygen radicals are released during the ischemic episode and the respiratory burst of phagocytosis is marked and prolonged. These events occur when effective antibacterial treatment is delayed when the diagnosis is not made early or when socioeconomic factors prevent treatment. The scarring of chronic pyelonephritis leads to the loss of renal tissue and function and may progress to end-stage renal disease. With effective antibacterial therapy, the immune response by both T and B lymphocytes leads to antibodies that assist in bacterial eradication. Therapy must be both rapid and effective. In many instances, antibacterial agents may be used as outpatient therapy. If the Gram stain shows only gram-negative organisms and if the infection is community acquired, oral outpatient therapy with trimethoprim/sulfamethoxazole or a fluoroquinolone may suffice if the patient has no nausea. When the patient is septic, hospitalization and treatment with parenteral antibiotics are needed. Both ceftriaxone and gentamycin are cost-effective parenteral therapy because only once-daily dosing is needed. If gram-positive organisms are found, an enterococcus should be suspected, and a beta-lactam penicillin such as piperacillin or a third-generation cephalosporin such as ceftriaxone is indicated. If penicillin allergy exists, vancomycin should be used. If the patient does not improve rapidly, diagnostic studies including ultrasound and CT will assist in the diagnosis of obstruction, abscess, or emphysematous pyelonephritis. Most of these complications are now rapidly treated percutaneously, with surgical therapy following as needed. Complicated infections, such as those occurring in patients with anatomic abnormalities, stone, or immunosuppression, are often caused by organisms other than E. coli, and long-term antibacterial therapy often leads to fungal infections such as candidiasis. A recrudescence of tuberculosis is occurring, often with resistance to antituberculous drugs. The increased incidence has been associated with the immunosuppression of AIDS but is also occurring in intravenous drug users, perhaps because of poor nutrition but also owing to noncompliance with treatment. The symptoms of renal tuberculosis are usually limited to fever, frequency, urgency, and dysuria. Hematuria with sterile pyuria is the usual laboratory finding. The young urologist should remember this renal disease in the differential diagnosis of hematuria, because medical therapy can provide a cure.

Vesicoureteral reflux in children: incidence and severity in siblings

PURPOSE

We attempted to determine the incidence of vesicoureteral reflux in asymptomatic siblings of children with reflux at different ages and assess the incidence of renal damage in asymptomatic siblings with reflux.

MATERIALS AND METHODS

We reviewed radionuclide cystograms of 482 consecutively referred siblings of children with vesicoureteral reflux, including 295 girls and 187 boys 2 weeks to 12.8 years old (mean age 2.8 years). Ultrasonograms and renal cortical scintigrams of children with reflux were evaluated. All siblings were considered asymptomatic by the referring physicians.

RESULTS

The overall incidence of vesicoureteral reflux was 36.5%, and the incidence in girls and boys was 39.3 and 32.1%, respectively. Children 24 months old or younger had the highest incidence (45.7%) and the highest risk of bilateral reflux. From ages 25 to 72 months the incidence of reflux was 33.1% and in siblings older than 72 months it was 7%. Reflux of urine to the level of the renal pelvis was detected in 28.6% of all referred siblings. Renal damage was observed on sonography or scintigraphy in 4.7% of the siblings with reflux.

CONCLUSIONS

The high incidence of vesicoureteral reflux through age 72 months indicates that it is important to screen siblings of children with reflux at an early age to prevent renal damage, which can occur in the absence of symptomatic urinary tract infection.

Drainage and reflux characteristics of antireflux ureteral double-J stents

We tested three antireflux double-J stents and compared them with common double-J stents in ex vivo canine urinary systems. At a physiologic flow rate, the drainage function of the antireflux stents proved to be sufficient; however, at a supraphysiological flow rate, drainage was inferior to that of the common double-J stent. Our reflux study demonstrated high-grade reflux with the common double-J stent, which transmitted more than 90% of the bladder pressure to the renal pelvis. The antireflux stents prevented this to a certain degree by both a reduction in and a delay of pressure transmission to the renal pelvis. In preliminary clinical trials, vesicorenal reflux was not detectable radiologically with the antireflux stents.