Value of CT for acute left-colonic diverticulitis: the surgeon's view

To determine the immediate and later role(s) of initial CT in patients presenting with their first episode of acute left-colonic diverticulitis.

Prospective inclusion of 542 patients hospitalized in the University Hospital of Geneva between 1986 and 1997. 465 (86%) patients had a CT. CT grading of diverticulitis was divided between moderate diverticulitis (no sign of colonic perforation) and severe diverticulitis (signs of colonic perforation).

During the index hospitalization, surgical treatment of the first episode of acute diverticulitis was needed in 26% of patients with CT-severe diverticulitis compared to 4% for patients with CT-moderate diverticulitis. At 5 years of follow-up after medical treatment of the first episode, incidence of remote complications was the highest (49%) for patients with CT-severe diverticulitis and the lowest (22%) for patients with CT-moderate diverticulitis. Finally, we found that the location of the diseased segment, which is important to guide the type of resection in case of elective surgery, varies in 35% of patients who had 2 episodes of acute diverticulitis.

CT is the indispensable tool both to confirm the suspected diagnosis of acute diverticulitis and to appreciate the risk of surgical treatment during the initial acute episode. Moreover, CT grading of diverticulitis is a statistically significant prognostic parameter of the chance of secondary complicated outcome after a first acute diverticulitis episode successfully treated medically. Finally, CT gives the exact location of diverticulitis. In case of elective surgery this colonic segment should be removed.