Reprint requests to: publications@acr.org Anorectal Disease Discussion of Procedures by Variant Variant 1: Suspected perianal disease. Abscess or fistula. Initial imaging. Anorectal abscesses result from infection of the intersphincteric anal glands. Obstruction of the draining duct may produce an intersphincteric abscess or the infection may rupture through the external sphincter to form an abscess in the ischiorectal or ischioanal spaces. Cephalad extension results in a high intramuscular or perirectal abscess, or a supralevator abscess if it extends above the levator muscles. Posterior extension may result in a horseshoe abscess in the intersphincteric plane or ischiorectal fossa [4]. Patients with anorectal abscess may present with pain that is typically throbbing, visible redness and swelling of the anus, and/or sepsis. On physical examination, there is often tenderness to palpation and an area of fluctuance. In some cases, the abscess may be occult on physical examination. The majority of anal fistulae (fistula-in-ano) arise from a preexisting abscess and as such are believed to represent a spectrum of the same disease. Clinically, patients with fistula-in-ano present with drainage of blood, pus, or fecal material from an external opening in the perianal region, intermittent pain, and perianal itching. The majority of patients with fistula-in-ano are male (2:1) and have a mean age at presentation of 40 years [5]. Other diseases that may cause anal fistula include CD, radiation proctitis, foreign body, prior anal surgery, infections (such as human immunodeficiency virus [HIV], tuberculosis, actinomycosis), and malignancy [6]. Perianal fistulae are a very common component of CD, occurring in 13% to 27% of these patients [7,8]. Perianal fistulae may be the initial manifestation of CD in up to 81% of patients who develop perianal disease, and in a small number of patients, it is the only manifestation of their disease [9]. Complex and multifocal fistulae are more common in CD.
Anorectal Disease. Reprint requests to: publications@acr.org Anorectal Disease Discussion of Procedures by Variant Variant 1: Suspected perianal disease. Abscess or fistula. Initial imaging. Anorectal abscesses result from infection of the intersphincteric anal glands. Obstruction of the draining duct may produce an intersphincteric abscess or the infection may rupture through the external sphincter to form an abscess in the ischiorectal or ischioanal spaces. Cephalad extension results in a high intramuscular or perirectal abscess, or a supralevator abscess if it extends above the levator muscles. Posterior extension may result in a horseshoe abscess in the intersphincteric plane or ischiorectal fossa [4]. Patients with anorectal abscess may present with pain that is typically throbbing, visible redness and swelling of the anus, and/or sepsis. On physical examination, there is often tenderness to palpation and an area of fluctuance. In some cases, the abscess may be occult on physical examination. The majority of anal fistulae (fistula-in-ano) arise from a preexisting abscess and as such are believed to represent a spectrum of the same disease. Clinically, patients with fistula-in-ano present with drainage of blood, pus, or fecal material from an external opening in the perianal region, intermittent pain, and perianal itching. The majority of patients with fistula-in-ano are male (2:1) and have a mean age at presentation of 40 years [5]. Other diseases that may cause anal fistula include CD, radiation proctitis, foreign body, prior anal surgery, infections (such as human immunodeficiency virus [HIV], tuberculosis, actinomycosis), and malignancy [6]. Perianal fistulae are a very common component of CD, occurring in 13% to 27% of these patients [7,8]. Perianal fistulae may be the initial manifestation of CD in up to 81% of patients who develop perianal disease, and in a small number of patients, it is the only manifestation of their disease [9]. Complex and multifocal fistulae are more common in CD.