Determinants of treatment and outcomes of diverticular abscesses

Diverticular abscess diameter of 3-6 cm is generally accepted as a cutoff determining whether percutaneous drainage is recommended in addition to antibiotics, but this is not based on high-quality evidence. The aim of this study was to analyze the treatment choices and outcomes of patients with diverticular abscesses.

This was a retrospective cohort study conducted in an academic teaching hospital functioning as a secondary and tertiary referral center. Altogether, 241 patients with computer tomography-verified acute left-sided colonic diverticulitis with intra-abdominal abscess were collected from a database containing all patients treated for colonic diverticulitis in our institution during 2006-2013. The main measured outcomes were need of emergency surgery and 30-day mortality, and these were compared between antibiotics only and percutaneous drainage groups. Treatment choices, including surgery, were also analyzed for all patients.

Abscesses under 40 mm were mostly treated with antibiotics alone with a high success rate (93 out of 107, 87%). In abscesses over 40 mm, the use of emergency surgery increased and the use of antibiotics alone decreased with increasing abscess size, but the proportion of successful drainage remained at 13-18% regardless of the abscess size. There were no differences in failure rate, 30-day mortality, the need of emergency surgery, permanent stoma, recurrence, or length of stay in patients treated with percutaneous drainage vs. antibiotics alone, even when groups were adjusted for potential confounders.

Percutaneous drainage as a treatment for large abscess does not seem to be superior to the treatment with only antibiotics.