Urinary diversion via cutaneous vesicostomy in the megabladder mouse.

Lower urinary tract obstruction in mice can lead to end-stage renal disease and death. We have developed a surgical technique to create a cutaneous vesicostomy in mice providing an external outlet for drainage of urine, thereby relieving the obstruction and slowing and/or preventing the development of end-stage renal disease and death.

The prenatal diagnosis of Beckwith-Wiedemann syndrome using ultrasound and magnetic resonance imaging.

Beckwith-Wiedemann syndrome is a rare congenital overgrowth syndrome. It carries important connotations for the pediatric urologist because it is associated with an increased risk for developing certain embryonal tumors. Until recently, these patients were not diagnosed until after birth; however, with newer imaging modalities, this syndrome may be diagnosed prenatally. We present a case of Beckwith-Wiedemann syndrome, depicting the prenatal modalities that may be used to diagnose this unusual condition.

Pathogenesis of renal injury in the megabladder mouse: a genetic model of congenital obstructive nephropathy.

Congenital obstructive nephropathy (CON) is the most common cause of chronic renal failure in children often leading to end-stage renal disease. The megabladder (mgb) mouse exhibits signs of urinary tract obstruction in utero resulting in the development of hydroureteronephrosis and progressive renal failure after birth. This study examined the development of progressive renal injury in homozygous mgb mice (mgb-/-). Renal ultrasound was used to stratify the disease state of mgb-/- mice, whereas surgical rescue was performed using vesicostomy. The progression of renal injury was characterized using a series of pathogenic markers including alpha smooth muscle isoactin (α-SMA), TGF-ß1, connective tissue growth factor (CTGF), E-cadherin, F4/80, Wilm's tumor (WT)-1, and paired box gene (Pax) 2. This analysis indicated that mgb-/- mice are born with pathologic changes in kidney development that progressively worsen in direct correlation with the severity of hydronephrosis. The initiation and pattern of fibrotic development observed in mgb-/- kidneys appeared distinctive from previous animal models of obstruction. These observations suggest that the mgb mouse represents a unique small animal model for the study of CON.

Urethral triplication with meatuses terminating on the penis: a rare case presenting with bifid urinary stream.

Urethral duplication is an uncommon clinical finding, and classification systems have been described to explain the clinical findings. Urethral triplication is an extremely uncommon diagnosis, with few published case reports. We present the rare case of an infant noted to have a bifid urinary stream and found to have urethral triplication on voiding cystourethrography.

Occult ureteropelvic junction obstruction presenting as anuria and urinary ascites in an infant with antenatal, unilateral hydronephrosis.

OBJECTIVE: To discuss an unusual case of occult ureteropelvic junction obstruction. CASE: A premature male infant with severe, unilateral hydronephrosis presented to the emergency room with 20 h of dry diapers. Placement of urethral catheter did not return urine. Imaging revealed persistent hydronephrosis on the previously affected side and new-onset hydronephrosis with perirenal fluid on the contralateral side. Patient was taken to the operating room and forniceal rupture from occult ureteropelvic junction obstruction with urinary ascites was identified. The obstruction was surgically repaired at that time and his postoperative course was uncomplicated. DISCUSSION: While most agree on postnatal evaluation for some children with antenatal hydronephrosis, there is no consensus as to the timing and frequency of evaluation. The risk of significant obstruction in children with low grades of hydronephrosis is very low, and many are not followed. This is a rare case in which low-grade postnatal hydronephrosis resulted in significant clinical obstruction.