CHAPTER 17 Procedures for Benign Anorectal Disease
HEMORRHOIDS
INDICATIONS FOR SURGERY
PREOPERATIVE EVALUATION
COMPONENTS OF THE PROCEDURE AND APPLIED ANATOMY
COMPLICATIONS
ANORECTAL ABSCESS
BACKGROUND
The majority of anorectal abscesses result from infection originating in the anal crypts located at the dentate line. Abscesses are classified as perianal (60%), ischiorectal (20%), intersphincteric (10%), or supralevator (9%), depending on their location (Fig. 17-4). Deep postanal space abscesses represent a particular challenge. The deep postanal space is protected from view by the sacrum, and abscesses originating in this cavity may track circumferentially into the ischiorectal, intersphincteric, or supralevator space before they are diagnosed (Fig. 17-5). This pattern of spread results in what is known as a horseshoe abscess.