EXTRAVASATION OF URINE
Urine extravasates from the bladder or urethra and collects in the layers of the perineum or in the prevesical space (cave of Retzius).
- Trauma to bladder or urethra.
- Instrumentation like dilatation, catheterisation, cystoscopy.
- Infection like Gonococcus .
- Ischemia of the distal ureter, the most common cause of urinary extravasation, results in leakage at the ureterovesical anastomosis.
It may be superficial or deep.
1.Superficial: It is due to either bulbar urethral injury or due to bursting of periurethral abscess after urethral stricture. Once urine extravasates due to full thickness disruption of the urethra anteriorly, it collects in superficial perineal space. This space is a closed cavity all round except anteriorly where it communicates with scrotal subcutaneous tissue deep to fascia Colles, penis between superficial fascia and deeper Buck’s fascia, in the anterior abdominal wall deep to Scarpa’a fascia. It does not spread to thigh and ischiorectal space as Scarpa’a fascia is attached firmly to fascia lata of thigh. Superficial perineal space is closed above by inferior fascia of perineal membrane; below by fascia of Colles; laterally by ischiopubic rami. It is open and communicating only anteriorly.
Entire scrotum, penis and often lower abdominal wall are swollen containing urine. It is painful; patient cannot pass urine through urethra; severe pain and shock due to pelvic injury. Often sepsis occurs and skin sloughs of leading into urinary fistulas.
- Deep: Urine spreads upwards into the extraperitoneal space of the pelvis around the bladder and prostate into the anterior abdominal wall causing deep extravasation of the urine. Here rupture of urethra is at membranous part of the urethra much more proximal than superficial type.
- Pain, swelling in the perineum
- Retention of urine
- Suprapubic pain,
- CT scans