Urethrography in urethral trauma: tissue reaction to extravasation of contrast dye and iatrogenic infection.

The reaction of periurethral tissue to retrograde urethrography with 30 or 60% contrast dye and/or iatrogenic infection following a sharp, penetrating injury of the urethra was investigated in rabbits. Urine was diverted continuously by tubeless cystostomy throughout the experiment. The local healing processes did not differ from the normal reaction after urethrography with 10 ml 30 or 60% sodium-meglumine-amidotrizoate or instillation of 1--2 . 10(6) E. coli in 10 ml saline. An increased inflammatory reaction was only observed when urethrography and the instillation of E. coli saline was combined, thus increasing the total fluid volume instilled and with it probably also the intraurethral pressure. The results suggest that retrograde urethrography as a diagnostic procedure immediately after an acute urethral trauma is free of adverse effects on the normal healing processes if performed under aseptic standards, with a small volume of contrast dye and as low as instillation pressure as possible.