Editing Orthotopic Urinary Diversion (section)

== Background ==

* Ureterosigmoidostomy is the oldest form of urinary diversion.
* Urinary diversion has developed along 3 paths: a conduit form of diversion, continent cutaneous diversion, and most recently orthotopic diversion.
* '''Orthotopic neobladder'''
** '''Most closely resembles the original bladder in both location and function.'''
** '''Relies on the intact external rhabdosphincter continence mechanism'''
** Avoids the difficulties associated with the efferent continence mechanism of continent cutaneous reservoirs.
** Seldom requires intermittent catheterization
** '''Voiding is accomplished by relaxation of the pelvic floor musculature (as in normal voiding) along with a concomitant increase in intraabdominal pressure (Valsalva maneuver)'''
* Compared to continent cutaneous diversion, orthotopic diversion allows natural voiding, is simpler to construct, and is less likely to require revision surgery at a later date
* Demonstration in cystectomy specimens that urethral involvement was rare in the absence of tumor at the bladder neck was the key finding that allowed application of orthotopic urinary diversion to women undergoing cystectomy