Incidence of Development of Perianal Fistula after Perianal Abscess Surgery
Anorectal abscesses and fistulas can be thought of as two sequential phases of the same anorectal infectious process: an abscess represents the acute phase of infection, while a fistula represents the chronic phase of suppuration and fistula formation. [1] The majority of anorectal suppurative disease results from infections of the anal glands (cryptoglandular infection) found in the inter-sphincteric plane [2]. Their ducts traverse the internal sphincter and empty into the anal crypts at the formation of an abscess that enlarges and spreads along one of several planes in the perianal and perirectal spaces. As an abscess enlarges, it spreads in several directions. The most common presentation is a painful, tender swelling at the anal verge [3]. Treatment is Incision and Drainage as soon as diagnosis is confirmed. Drainage of anorectal abscess results in cure for about 50% patients. Remaining 50% develop a persistent fistula in ano. The fistula originates in the infected crypt (internal opening) and tracks to the outside (usually site of prior drainage), following the previous abscess cavity (Sabiston) [4].