A pregnant woman was referred at 23 weeks of gestation to pediatric urologist John Wiener, MD, after a routine ultrasound revealed enlarged bladder and kidneys in her male fetus.
A “keyhole” sign was noted on the fetus’ bladder, suggesting a bladder outlet obstruction (BOO). There was a normal amount of amniotic fluid, indicating that his bladder was getting urine out of his body sufficiently. If the amniotic fluid level had been low (oligohydramnios), prenatal intervention may have been indicated. Fortunately, for the woman and her unborn child, the amniotic fluid levels were followed closely and remained normal until delivery at 40 weeks.
After the child was born, Wiener was consulted in the nursery. A voiding cystourethrogram (VCUG) was performed, and the team was expecting to find posterior urethral valves—the most common cause of BOO in male newborns. Instead, the test indicated that there was no anatomical obstruction.
Question: Given that the child did not have posterior urethral valves, what else could be responsible for his bladder condition?
Answer: A functional, rather than an anatomical, obstruction was responsible. “The nerves to his bladder and sphincter weren’t working in concert,” says Wiener. Although pediatric urologists frequently see babies with congenital neuropathic bladder dysfunction due to spina bifida, Wiener says it’s very rare to see it in children without a spinal abnormality. “In fact, I was so incredulous about the VCUG not showing urethral valves that I took him to the operating room on his fourth day of life to confirm the absence of valves.”
The baby was discharged home the following day, voiding into his diaper, but he was soon readmitted to the hospital with a urinary tract infection and mild renal insufficiency. Given his dilated posterior urethra, only Wiener was able to insert a catheter into his bladder. This ruled out the baby’s parents performing clean intermittent catheterization, and Wiener knew he would need a more reliable treatment.
When the baby was 2 weeks old, cystoscopy again confirmed no anatomical obstruction, and Wiener performed a cutaneous vesicostomy—bringing the bladder mucosa up to the skin between the pubis and the umbilicus—to allow bladder drainage directly into the diaper and bypass his dysfunctional urinary sphincter. “With this procedure, his bladder was reliably empty all the time and his kidneys were at less risk for damage and infection,” says Wiener.
When the patient reaches school age and wearing diapers becomes a social issue, Wiener plans to close the vesicostomy and perform a continent catheterizable channel (Mitrofanoff) procedure to provide a permanent way for the boy to empty his bladder by clean intermittent catheterization without the discomfort of catheterizing his urethra.
“What makes this case unusual is that it seemed like the patient had BOO before he was born, but there was no anatomical blockage,” says Wiener, adding that he’s only seen this condition develop before birth one other time in his 21 years at Duke. “The child’s parents were told that he would not survive, but he’s now in the first grade, wearing underwear instead of diapers, and successfully catheterizing his bladder through the Mitrofanoff channel by himself.”
Although the patient has some degree of congenital chronic kidney disease because of poor bladder emptying before birth and has spent much of his young life fighting kidney infections, Wiener says his prognosis is excellent. “He’s had numerous infections because of his naïve immune system, but the risk of infection should go down as his immune system improves. The vesicostomy is keeping his bladder empty, and his kidneys are less dilated than before birth.”
The baby also benefits from the excellent collaborative care at Duke Children’s Hospital between the departments of Pediatric Urology and Pediatric Nephrology. They share a common clinic space so patients with urologic conditions that cause nephropathy can be seen by both specialties simultaneously.