Difficulty Removing a Urethral Catheter in a Boy Due to a "Hairpin-Fold" Deformity: A Case Report.

Urethral catheterization is a common procedure performed in pediatric patients. We encountered a 21-month-old boy who had difficulty removing a urethral catheter because of the formation of a bent shape during catheter removal. The circumstances and ultrasonographic findings indicated that the deeply inserted catheter had formed a hairpin-folded shape inside the bladder and was being pulled out. The tip of the folded catheter was inserted into the curved part near the symphysis pubis, which was assumed to make the catheter difficult to remove. The appropriate insertion length of the urethral catheter depends on the patient's age, sex, and whether a balloon is present or not. Therefore, we should be aware that such difficulty in removal can occur when a catheter is inserted deeper than necessary. The appropriate insertion length for each child must be considered when inserting a urethral catheter.