Intravesical self-tying knots in suprapubic catheters: a report of two cases.

We present two cases in which intravesical, self-tying knots occurred when the Cystofix catheter was used for suprapubic catheterization in two male boys admitted for hypospadias surgery. This complication of suprapubic catheterization is most likely due to the pigtail end of the catheter, and should be considered when removal is difficult.