Nocturnal overdistension may cause bladder deterioration

April 1, 2005

San Francisco--A previously unrecognized syndrome of nocturnal overdistension of the bladder (NOB) can cause bladder deterioration in children with neurogenic bladder. However, the condition is amenable to treatment by nighttime bladder emptying.

The strategy of nocturnal bladder emptying led to improvement or resolution in bladder deterioration in 14 of 18 children studied, as well as improvement or complete resolution of symptoms in a majority of patients with hydronephrosis, recurrent urinary tract infection, and incontinence.

"I would suggest that nocturnal bladder emptying is a simple technique for reversing urinary tract deterioration in children with neurogenic bladder," said Stephen Koff, MD, a pediatric urologist and professor of surgery, Ohio State University College of Medicine and Children's Hospital, both of Columbus.

An acquired condition Bladder deterioration often occurs in children with neurogenic bladder despite optimal therapy, Dr. Koff noted. The deterioration is marked by decreasing bladder capacity and compliance and sequelae that include hydronephrosis, recurrent UTI, and worsening incontinence. The condition often leads to surgical bladder augmentation procedures.

"Bladder deterioration in neurogenic bladder is assumed to be part of the natural history of neurogenic bladder disease in spina bifida," Dr. Koff said at the American Academy of Pediatrics Section on Urology annual meeting.

"Our experience with valve bladder syndrome suggests the deterioration can be caused by a syndrome of nocturnal overdistension of the bladder, which is reversible using nighttime bladder emptying."

As hypothesized by Dr. Koff and his colleagues, NOB is an acquired condition and not part of the natural history of neurogenic bladder. It results from occult nocturnal overdistension that results in elevated bladder storage pressures. As such, the condition should be reversible by means of nighttime bladder emptying.

The Ohio State group's experience with NOB has suggested that nocturnal bladder emptying is indicated in children with neurogenic bladder who develop progressive urinary tract deterioration despite idealized programs of daytime catheterization and urotropic medications.

Dr. Koff presented findings from 18 children (mean age, 137 months) with neurogenic bladder being managed by intermittent catheterization. In 14 cases, patients received a continuously draining nighttime catheter. In the remaining four, they had scheduled awakenings to perform catheterization.

The study group included six patients who had decreasing bladder capacity and compliance and who were candidates for bladder augmentation. Other manifestations of the disease process were progressive hydronephrosis (seven patients), increasing frequency of UTI (six patients), and worsening incontinence (three patients).

Nighttime emptying With nighttime bladder emptying, all but four patients had either improvement or resolution of the bladder deterioration and associated manifestations. All seven patients with hydronephrosis were improved or had complete resolution of the condition, and six of eight patients with recurrent UTI had improvement. Worsening incontinence resolved in three patients.

Of the six patients with decreased bladder capacity and compliance, four had increases in bladder capacity sufficient to avoid bladder augmentation. The largest gains were from 120 cc before treatment to 240 cc afterward and from 150 cc to 370 cc following treatment with nocturnal bladder emptying.

Calling NOB a condition equivalent to obstruction, Dr. Koff explained how nighttime bladder emptying could restore bladder capacity and compliance.

"The bladder is overstretched, which alters the bladder anatomically with thickening and also urodynamically," he said. "We know that elimination of obstruction reverses these changes. Bladder wall thickening regresses, and urodynamically there is improvement in capacity and compliance. Instability also will resolve in many patients."

The assumption that bladder deterioration is part of the natural course of neurogenic bladder has led to other potential causes of deterioration-such as NOB-to be overlooked.

"It has just always been assumed that, in some kids with neurogenic bladders, the bladders just sort of go off or deteriorate at some point in time as part of their natural history," Dr. Koff told Urology Times. "Our observations suggest that many of these children don't naturally go off.