Urethral instability as an important element of dysfunctional voiding

Purpose: We monitored detrusor and urethral behavior during bladder filling in girls with dysfunctional voiding (incomplete perineal relaxation) to de termine the causes of this pathological condition. Materials and Methods: In 15 girls without neuropathy but with a staccato v oiding pattern in whom symptoms of urinary tract infection and urge inconti nence were refractory to treatment we recorded urethral and bladder pressur e, and anal sphincter needle electromyography throughout slow bladder filli ng. Results: Urethral instability was observed in 8 of the 15 girls as urethral pressure decreases with short periods of electromyography silence (6) or a s intermittent urethral pressure increases with short perineal spasms (2). Detrusor instability was noted in 12 girls, while bladder pressure was norm al in 1 and hypoactive in 2. In 6 cases of an unstable bladder urethral pre ssure decreases with silent electromyography periods were also noted. In 1 case low basic urethral pressure had short periods of increased pressure wi th electromyography bursts. Ln another case high compliance bladder uninhib ited sphincter contractions were noted throughout filling. Conclusions: Dysfunctional voiding is a misleading term since a pathologica l condition is also present during the bladder filling phase. Frequently ob served detrusor and urethral instability may explain the urge sensation dur ing filling and the staccato voiding phase.