BackgroundOccasionally, difficulty with standard urethral catheterization is encountered. ObjectiveWe conducted a pilot study to evaluate whether transabdominal ultrasound (TAUS) showed the tip of a urethral catheter and whether TAUS-guided catheterization with transrectal pressure is successful in male patients in whom performing standard catheterization is difficult. MethodsThe eligible study participants included adult male patients in whom standard catheterization failed in our emergency department or who were transferred from other facilities after failure of catheterization and subsequent urethral bleeding. The enrolled patients included those in whom the tip of a catheter could not be advanced through the posterior and bulbar urethra judging from the inserted length. First, an emergency nurse advanced a catheter until the progress was obstructed. Next, an emergency physician performed TAUS to detect the tip of the catheter. If the tip was detected, the physician inserted the index finger into the rectum and kept pushing the site of the obstruction. After following these procedures, the nurse again advanced the catheter. ResultsSix patients were enrolled. The tip of a catheter was detected in the urethra or the false passage using TAUS in 4 of the 6 patients. In these 4 patients, the curve of the urethra became gentle or the false passage was compressed by transrectal pressure and the tip was advanced smoothly to the bladder. ConclusionsIn some male patients in whom performing standard urethral catheterization is difficult, TAUS reveals the tip of the catheter and TAUS-guided catheterization with transrectal pressure can be safe and useful.