Anal fistula is an abnormal communication between an opening in the perianal skin and an opening in the anal canal. It can be described as a tunnel between these openings. Usually a small quantity of pus is seen coming out of the skin opening.
Anal fistula develops after drainage of a perianal abscess. If the abscess was caused because of an intraanal opening, the abscess can reappear after simple drainage. if the site of drainage does not heal completely, a small opening remain with a small quantity of pus coming out.
Perianal inflammation and fistula is quite common in patients with Crohn’s disease (bowel inflammation).
The anatomic site of perianal fistula can be easily diagnosed with intraanal ultrasound or NMR. From our 20 years experience, endoanal ultrasound provides the colorectal surgeon with all necessary information for a safe operative treatment of perianal fistula.
Fistula mapping with endoanal ultrasound provides following necessary informations about the fistula tract
- The cause of perianal fistula (intraanal opening)
- The fistula tract and ramifications
- The involvement of anal sphincters in the perianal fistula
- Preoperative endoanal ultrasound is mandatory in women (short sphincters- obstetric tear of sphincters)
- In case of fistula recurrence (diagnosis of operativesphincteric trauma).
- After a detailed mapping, surgical operation is safe and effective