Posterior ledge at the bladder neck: crucial diagnostic role of ultrasonography.

A posterior ledge at the bladder neck was seen in 158 patients (107 of whom were undergoing intermittent catheterization) on a sonographic voiding cystourethrogram. In 117 patients, the ledge was 0.5 cm or longer; 66 patients were on intermittent catheterization, and 51 experienced difficulty with catheterization, including vigorous bleeding in 4. Ledges less than 0.5 cm were discovered in 41 patients, all on intermittent catheterization, none of whom had difficulty with this procedure. The duration of intermittent catheterization and of detrusor-sphincter dyssynergia was shown statistically to be an important factor leading to the formation of the longer obstructing ledges (P less than 0.0005, Mann-Whitney test). Sphincterotomies were performed in 74 patients through the periurethral striated sphincter at 10 and 2 o'clock and extended to the bladder neck. The operation was a success in 73 (98%), all of whom were catheter-free, and in all of whom sonography revealed that the ledge had receded and the catheter was no longer obstructed.