Perianal fistula: trans-sphincteric

Case contributed by Dr Dalia Ibrahim


History of perianal fistula and purulent discharge.

Patient Data

Age: 30 years
Gender: Male

Right trans-sphincteric perianal fistula starts at right perianal cutaneous opening and extends within the right ischio-anal and ischiorectal fossae. it then pierces the external anal sphincter opposite 10 o'clock to connect with horse-shaped tract within the inter-sphincteric plane. It ends by piercing the internal anal sphincter opposite 6 o'clock.

The fistula is filled with fluid signal and shows thick hypointense signal. Edema and smudging of the right ischiorectal fat planes around the aforementioned collection is noted. No abscess, or extension cranial to the levator ani.

No associated secondary tracts within the ischiorectal or ischioanal fossae.



Injection of contrast via the external opening showed opacification of the right perianal fistula which travels superiorly. It shows a small horizontal medial ramification with obvious contrast seen to flow into the anal canal and rectum suggestive of communication with the anal canal.

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Case information

rID: 47586
Published: 30th Aug 2016
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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