Purpose: The aim of of this study was to evaluate prospectively the long-term outcome of mesocolic and pelvic diverticular abscesses of the left colon.
Methods: Between October 1986 and October 1997, a total of 465 patients urgently admitted to our hospital with a suspected diagnosis of acute left-sided colonic diverticulitis had a CT scan. Of 76 patients (17 percent) who had an associated mesocolic or pelvic abscess, 3 were lost to follow-up. The remaining 73 patients (45 with a mesocolic abscess and 28 with a pelvic abscess) were followed for a median of 43 months.
Results: of the 45 patients with a mesocolic abscess, 7 (15 percent) required surgery during their first hospitalization versus 11 (39 percent) of the 28 patients with a pelvic abscess (P = 0.04). At the end of follow-up, 22 (58 percent) of the 38 patients with a mesocolic abscess who had successful conservative treatment during their first hospitalization did not need surgical treatment vs. 8 (47 percent) of the 17 who had a pelvic abscess. Altogether, 51 percent of the patients with a mesocolic abscess had surgical treatment versus 71 percent of those with a pelvic abscess (P = 0.09).
Conclusions: Considering the poor outcome of pelvic abscess associated with acute left-sided colonic diverticulitis, percutaneous drainage followed by secondary colectomy seems justified. Mesocolic abscess by itself is not an absolute indication for colectomy.