Transurethral incision of congenital obstructive lesions in the posterior urethra in boys and its effect on urinary incontinence and urodynamic study.

OBJECTIVE: • To evaluate the clinical significance of congenital obstructive lesions of the posterior urethra in boys with refractory primary nocturnal enuresis. PATIENTS AND METHODS: • VCUG was performed in 43 consecutive boys who visited our department from April 2004 to April 2009 who were unresponsive to conservative treatment. 20 patients of the 43 patients, underwent TUI. VCUG and UDS were performed before and 3–4 months after TUI. • In UDS, the maximum flow rate (Q max ), maximum bladder capacity, and post-voiding residual urine volume were determined using uroflowmetry (UFM), and the detrusor pressure (P det ) at Q max was determined in a pressure flow study (PFS). • Clinical outcome was evaluated 3–4 months and 6 months after TUI. RESULTS: • In VCUG performed 3–4 months after TUI, improvement was observed in urethral morphology in all patients. In preoperative PFS, two patterns were observed: 13 patients(65%) had a synergic pattern (SP) in which the P det increased with increasing urinary flow rate simultaneously with the initiation of voiding and seven (35%) had a dyssynergic pattern (DP) in which the P det was not coincident with the initiation of voiding, but was higher immediately before voiding than at Q max . TUI was effective only in the SP group: symptomatic improvement was observed in 87.5% of patients with daytime incontinence and 77% of patients with nocturnal enuresis 6 months after TUI. • In the DP group, no effect was observed (0%). With regard to changes in UDS parameters, a significant decrease ( P= 0.0004) was observed in the P det at Q max and a significant increase ( P = 0.036) was observed in the maximum bladder capacity in the SP group, whereas no significant differences were noted in any parameters in the DP group. CONCLUSION: • Two voiding urodynamic patterns with different clinical outcomes of TUI were detected among patients with congenital posterior urethral obstruction, the underlying disease of refractory primary nocturnal enuresis in boys. [ABSTRACT FROM AUTHOR]