Urethra fistulae

Simply stated, UI may occur only as a result of abnormalities of the urethra (including the bladder outlet and urinary sphincter) or the bladder, or from a combination of abnormalities of both structures. Abnormalities may result in either overfunction or underfunction of the bladder and/or urethra with the resulting development of UI. While this simple classification scheme excludes extremely rare causes of UI such as congenital ectopic ureters and urinary fistulas, it is useful in gaining a working understanding of the condition. 

Retrograde urethrography is the best way to study fistulae located under the striate sphincter of the urethra since it can visualize the fistula, the concomitant cavities and passage of the contrast agent into adjacent organs. 

Fistulae developing in the posterior urethra are better detected using voiding cystourethrography. CT is used for monitoring and identifying the extent of the periurethral and periprostatic fluid collections. 

The term imperforate anus includes all kinds of anorectal malformations from covering of the anus by a thin skin membrane to high anorectal atresia - with or without a fistula, into the urethra or bladder - and to cloacal anomalies in females. It is well known that a high proportion of patients with imperforate anus have this maldevelopment in association with anomalies of one or several other... 

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