Is it necessary to catheterise the bladder before laparoscopy?

Fifty patients had residual urine measured by catheterisation immediately before laparoscopic cholecystectomy. The median amount of urine in the bladder was 100 ml (range 5-500 ml). This urine volume does not distend the bladder enough to risk inadvertant perforation during insertion of a subumbilical port. Urinary bladder catheterisation is unnecessary before laparoscopy especially if the bladder is impalpable.