urinary diversion

Urinary diversion is created after the removal of the urinary bladder (radical cystectomy or cystoprostatectomy, usually done to treat invasive bladder cancer).

There are three main varieties:

• neobladder formed from a segment of ileum (i.e. ileal conduit, also known as a "Bricker conduit")
  • the segment of ileum extends to an ostomy on the abdominal wall
• neobladder reservoir formed from bowel with cutaneous diversion, e.g.
  • Indiana pouch: formed from cecum and terminal ileum
  • Kock ileal reservoir: formed entirely from distal ileum
  • Mitrofanoff appendicovesicostomy: bladder augmented with a segment of small bowel, and the appendix is used as a conduit to the abdominal wall
• "orthotopic" neobladder
  • e.g. Studer pouch, T-pouch neobladder, W-reservoir, Kock ileal pouch
  • an isoperistaltic, tubular segment of ileum is formed into a pouch
  • the outlet is the native urethra

The ureters can also exit directly to the skin surface (cutaneous ureterostomy), but this is only performed if neither large nor small bowel are candidates for diversion.

The types of urinary diversion with a reservoir or neobladder are considered "continent" types of urinary diversion.

Radiographic features

The imaging appearance depends on the type of neobladder formed.

Methods of radiological assessment include all modalities, with a unique fluoroscopic study being a loopogram via the conduit stoma.

Treatment and prognosis

Complications

• ileus or small bowel obstruction
• bowel ischemia
• anastomotic leak
• urine leak and urinomas
• pyelonephritis
• fistula formation
• ureteroenteric and neovesical-urethral anastomotic stricture
• urolithiasis
• worsening renal failure

Siehe auch:

• neobladder