Free perforation during the first episode of acute diverticulitis: can it be avoided?

The aims of the present study are to compare the severity of acute diverticulitis in the first episode and in later bouts, and to determine whether there are risk factors for the presence of free perforation at the onset of diverticulitis. A single-center retrospective study was conducted of patients who developed a first episode of acute diverticulitis between January 2011 and August 2021 diagnosed by computed tomography and followed up for at least 1 year. Free perforation was considered to be present in patients with diverticulitis stage III and IV according to the Hinchey classification (modified by Wasvary). The analysis included 394 patients (224 men and 170 women) with a mean age of 58 years. Forty-eight patients (12.2%) presented free perforation at some point in the course of the disease, 43 during the first episode and 5 during subsequent bouts. The perforation subgroup showed higher rates of stoma creation and mortality (relative risks of 12.3 and 23.5, respectively). In the multivariate analysis, age (OR: 1.041 95% CI 1.016-1.067), lung disease (OR 2.154 95% CI 1.038-4.472) and immunosuppression (OR: 2.812 95% CI 1.315-6.015) were independent factors for free perforation at diverticulitis onset. Free perforation occurs more frequently during the first episode of acute diverticulitis. Older patients, immunosuppressed patients and those with respiratory disease have a greater risk of presenting freely perforated diverticulitis. Therefore, it is essential to maintain a high level of clinical suspicion in these patients to activate early focus control and thus avoid fatal outcomes.