Parks and Stitz  demonstrated that hospital stay and healing times was much longer in patients treated for transsphincteric
and suprasphincteric as compared with those treated for an intersphincteric fistula.
According to Parks, 1976, they are classified as: intersphincteric (60-75%), transsphincteric
, low and high level (15-20%), and suprasphincteric (5%) .
14, 15) Differentiating between inter- and transsphincteric
fistulas is important for surgical planning and is typically described according to the St.
Different surgical approaches described include transanal, transsphincteric
, and transabdominal; however, there is no general consensus regarding optimal treatment.
Complex perianal disease was defined according to the American Gastroenterology Association recommendation as 'fistulas that are high intersphincteric, high transsphincteric
, extrasphincteric or suprasphincteric, have multiple external openings, are associated with a perianal abscess, fistulise to adjacent organs, are associated with the presence of an anorectal stricture or associated with the presence of active rectal disease.
Six patients had intersphincteric fistulas and 3 had transsphincteric
Treatment of transsphincteric
anal fistulas by the seton technique.
Colosigmoid Adenocarcinoma Anastomotic Recurrence Seeding Into a Transsphincteric
Fistula-in-ano: A Clinical Report and Literature Review.
Experience with 30 posttraumatic rectourethral fistulas: presentation of posterior transsphincteric
anterior rectal wall advancement.
The vast majority of anal fistulas are intersphincreric or transsphincteric
This group includes subcutaneous, intersphincteric or low transsphincteric
fistulae and can be categorized as simple anal fistula.