Management of Wilms tumor: current standard of care.

Wilms tumor is the most common renal malignancy in children. In the 1930s, overall survival for children with Wilms tumor was approximately 30%. Use of multidisciplinary therapy, guided by results from multi-institutional, randomized trials, has substantially improved overall survival to about 90%. Management of Wilms tumor differs substantially between Europe and the US. In Europe, the International Society of Pediatric Oncology protocols call for management of patients with presumptive Wilms tumor with neoadjuvant chemotherapy followed by nephrectomy and further chemotherapy. In the US, protocols developed by the National Wilms Tumor Study Group advise primary nephrectomy followed by a chemotherapy regimen tailored to the pathologic tumor stage. Despite these disparate strategies, overall survival is similar in patients managed according to European and US protocols. Patients with Wilms tumor now have excellent survival. Therefore, current goals aim to reduce the morbidity associated with therapy. Important complications of treatment for Wilms tumor include cardiomyopathy, renal failure, and increased risk of a secondary malignancy. Currently, the role of laparoscopic surgery in management of Wilms tumor remains extremely limited.

Urinary incontinence in girls.

Girls with incontinence may have minor irritative conditions or undiagnosed anatomic abnormalities that may require surgery. These abnormalities can be identified during a comprehensive history and physical examination that focuses on voiding signs and symptoms. Urinary tract infection and constipation if present should be identified. Most girls with daytime wetting will respond to conservative therapy using timed voiding, dietary changes, and anticholinergic medication. Uroflowmetry with a postvoid residual urine measurement can identify girls who may benefit from biofeedback to treat pelvic floor dysfunction. Formal urodynamics and spinal magnetic resonance imaging should be done in girls refractory to treatment. Instruments and tools to quantify dysfunctional voiding symptoms are being developed. Because most dysfunctional voiding will be treated clinically, these validated tools will be useful in documenting severity of symptoms and clinical outcomes.

Structural changes in the bladder walls of pregnant and hormone-treated rats: correlation with bladder dynamics.

OBJECTIVE: To evaluate the effects of oestrogen, progesterone and pregnancy on bladder dynamics, and assess the associated histological and structural changes in the bladder wall in a rat model. MATERIALS AND METHODS: Adult female Sprague-Dawley rats were divided into groups and treated as follows: nonpregnant controls (NC); pregnant (PG); oophorectomized and treated with oestrogen (ES); oophorectomized and treated with progesterone (PR); and oophorectomized controls (OO). Simultaneous and continuous renal pelvic and bladder pressures were recorded during bladder filling and emptying. Connective tissue and smooth muscle were analysed morphometrically and quantitatively, and immunohistochemistry used to evaluate the distribution and expression of collagen types I, III and IV. RESULTS: PG rats had significantly greater bladder compliance than NC, OO and PR rats (P < 0.05). This correlated with the morphometric analysis, with bladders of PG and PR rats having lower connective tissue to smooth muscle ratios than NC, ES and OO rats (P < 0.05). Collagen I was increased in the lamina propria of PG and ES rats, and the detrusor muscle layer showed greater localization of collagen III in the interfascicular space in the PG and PR rats than in the other groups. There was no change in the distribution of collagen IV. CONCLUSION: PG and PR rats had the highest bladder compliance and the changes paralleled structural changes in the bladders, specifically in the ratio of connective tissue to smooth muscle, and the distribution and expression of collagens I and III. These changes have age-related implications in the urinary tract.

Effect of urinary tract infection on ureteropelvic junction obstruction in a rat model.

OBJECTIVES: When a partially obstructed kidney becomes infected, more rapid and extreme renal parenchymal damage appears to occur than might result from either infection or obstruction alone. Previously, we showed that either bacteriuria or partial obstruction in congenital unilateral hydronephrosis causes elevated renal pelvic pressures in a rat model. In this same model, we examined the combined effects of partial upper tract obstruction and bacteriuria on renal pelvic and bladder pressures. METHODS: Female rats from an inbred colony in which more than one half are born with unilateral obstructive hydronephrosis were studied. Type 1 piliated Escherichia coli was instilled into the bladder. Two to 6 days later, the bladder and renal pelvic pressures were measured during varying urinary flows (less than 2 to more than 30 mL/kg/hr). All animals were killed and the kidneys and bladder grossly and histologically assessed. Hydronephrosis was determined at pathologic examination. RESULTS: Eight rats had congenital unilateral hydronephrosis; five were normal. Acute inflammation was found in all bladder and renal specimens. In hydronephrotic, infected kidneys, the renal pelvic pressures exceeded those in nonhydronephrotic, infected kidneys at all urinary flow rates. Bladder capacity and pressures did not differ between the two groups. CONCLUSIONS: This model demonstrates that the combination of infection and obstructive hydronephrosis in this model causes renal pelvic pressure elevation that is higher than that associated with either infection or obstructive hydronephrosis alone. These data demonstrate the compound effect that infection and obstruction may have on the kidney and offers an explanation for why this clinical situation is more likely to be associated with greater renal parenchymal injury than either alone.