Urodynamic findings in children with isolated epispadias

The exstrophy-epispadias complex represents a spectrum of anomalies with variable implications for upper and lower urinary tract function. Successful treatment of incontinence in this population is challenging and often elusive. To date few studies have focused on urodynamic findings specific to primary epispadias.

We retrospectively reviewed the records of patients presenting with primary epispadias in the absence of bladder exstrophy. We identified 18 boys and 12 girls, of whom 16 underwent formal urodynamic evaluation before (5), after (6) or before and after (5) surgical narrowing of the bladder neck. Bladder capacity was recorded as percent of expected capacity for age. Bladders were considered hypertonic when end filling pressure was greater than 20 cm. water. End filling pressure was defined as the pressure at which urinary leakage was noted or the patient had discomfort. Uninhibited contractions were considered significant when the amplitude was greater than 15 cm water. The ability of the detrusor to generate a voiding contraction at the end of the filling phase was also recorded. Urodynamic studies were performed with a balloon catheter occluding the incompetent bladder neck or with a standard urodynamic catheter after formal bladder neck repair.

Before bladder neck repair average bladder capacity was 157 ml (range 55 to 450), corresponding to 52% (range 22 to 100) of expected capacity. Significant uninhibited contractions were noted in 2 patients. In 7 of the 9 evaluable patients (78%) a voiding contraction was generated. In children in whom urodynamic studies were done after surgery mean bladder capacity was 260 ml (range 77 to 660), corresponding to 76% (range 36 to 147) of expected capacity. Hypertonicity and hyperreflexia were noted in 3 and 2 patients, respectively. In 5 of the 11 cases (46%) a voiding bladder contraction was generated. Of the 5 patients who underwent urodynamic evaluation before and after bladder neck repair the percent increase in bladder capacity was significantly greater in the 2 boys (67 and 110%, respectively) than in the 3 girls (-20, 10 and 20, respectively).

The most frequently noted urodynamic pattern before surgical correction of the bladder neck in patients with isolated epispadias is a low capacity, highly compliant bladder with minimal detrusor dysfunction. Postoperatively capacity increases, albeit to a greater extent in boys than in girls, and the incidence of detrusor dysfunction increases as well. In some patients classic bladder neck repair may result in detrimental bladder dynamics due to as yet poorly elucidated mechanisms.