Perforated diverticulitis of the sigmoid colon revealed by a perianal fistula

Abstract

IntroductionDiverticular disease of the colon is a frequent pathology; however, perforated diverticulitis with a spontaneous sigmoidocutaneous fistula revealed by a perianal abscess is an uncommon presentation. We present this extremely rare case of a perforated sigmoid diverticulum in the perianal area, which is the first case that we have encountered in our practice and in the literature, along with the accompanying diagnostic and therapeutic issues and a review of the literature.Presentation of caseWe report the case of a 47-year-old man who was admitted to the emergency room due to a perianal abscess. The patient was taken to the operating room on an emergency basis. In the lithotomy position, the abscess was located at the 4 o’clock position. Incision and drainage was performed. Intraoperatively, the abscess was found to be deep, and considered an ischiorectal abscess. No fistulous tract was identified. An MRI of the pelvis was performed one month postoperatively which revealed a perforated diverticulitis of the sigmoid colon causing a perianal fistula. After the abscess was successfully treated, a sigmoidectomy was performed. Fifteen centimeters of the colon were resected. No postoperative complications occurred.DiscussionPerianal fistula is an obvious physical sign but its etiology is complex to determine. The pathophysiological mechanism involved is the emergence of a pressure gradient between the peritoneum and surrounding structures, causing rupture of the perianal tissue, allowing gas from a perforation to diffuse along tissue planes.ConclusionGeneral surgeons should bear in mind this rare presentation of a sigmoid diverticulitis.

Spontaneous colocutaneous diverticular fistula presenting as perianal abscess

“…[1][2][3][4] Elective operations for diverticular fistulae are usually difficult. Spontaneous diverticular colocutaneous fistulae, especially to the perineum are even rarer, with only four cases found in the literature since 2000.…”

“…[1][2][3][4] Elective operations for diverticular fistulae are usually difficult. Absence of an anal fistula and the high extent of the abscess cavity prompted a magnetic resonance imaging scan, which demonstrated a tract extending from sigmoid colon to the ischioanal abscess.…”

“…Spontaneous diverticular colocutaneous fistulae, especially to the perineum are even rarer, with only four cases found in the literature since 2000. [1][2][3][4] Elective operations for diverticular fistulae are usually difficult. They are often performed open due to issues with abdominal access and difficulties identifying dissection planes.…”

Ischio‐anal abscess as a first presentation of complicated diverticular disease

“…Colocutaneous fistula formation is one such complication, and has been described in a number of anatomical locations . The peri‐anal region is an exceedingly rare location for this complication, with only one prior case reported . This case report describes a colocutaneous fistula arising secondary to sigmoid diverticular disease and presenting as a recurrent ischio‐anal abscess.…”

“…Spontaneous colocutaneous fistula formation is exceedingly rare with a wide range of sites having been described, including the abdomen, the thigh and the popliteal fossa . To our knowledge, there has only been one previous case report of a peri‐anal abscess as the initial presentation of diverticular disease …”