Two Different Formation Routes of the Pelvirectal Fistula

Abstract

Thirty-nine cases of pelvirectal fistula and abscess were classified by jack-knife position MRI into two types of disease in terms of the routes for the fistulas to reach the pelvirectal fossa: levator ani penetrating type in 10 cases and intersphincteric space ascending type in 29 cases.
The levator ani penetrating type is defined as a disease producing abscesses at the pelvirectal fossa penetrating through the levator ani after rupturing the anal sphincters and presenting with the form of ischiorectal fistula. The levator ani penetrating type includes many postoperative recurrent cases, and almost all of them clearly have a primary abscess in the deep part of the external anal sphincter, located posteriorly. The intersphincteric space ascending type is defined as a disease producing abscesses at the pelvirectal fossa, the small fistulous tract ascending from the primary orifice in the intersphincteric place, located posteriorly. In the intersphincteric space ascending type, there are many cases without a clear primary abscess in the deep part of the external anal sphincter and lesion in the ischiorectal fossa. The intersphincteric space ascending type is considered the essential form of pelvirectal fistula. These forms should be considered as two discrete diseases with completely different pathological conditions.