Long-term follow-up after first acute episode of sigmoid diverticulitis: Is surgery mandatory? A prospective study of 118 patients

PURPOSE: This study was designed to evaluate the long-term natural history of sigmoid diverticulitis in patients treated nonoperatively after a first acute episode and to assess the role of elective colectomy. METHODS: Between 1986 and 1991, 144 patients were admitted for acute diverticulitis diagnosed by abdominal computed tomography and had a successful nonoperative treatment. Remote complications (persisting or recurring diverticulitis) were also diagnosed by computed tomography. Patients had a poor outcome if they had one of these complications. Diverticulitis was graded mild or severe on computed tomography according to Ambrosetti's criteria. We determined statistically whether young age (:! 50 years old) and severe diverticulitis were risk factors for a poor outcome. RESULTS: One hundred eighteen patients with a contributive computed tomographic scan at admission were followed up. Median age was 63 (range, 23-93) years, with a median follow-up of 9.5 (range, 0.2-13.8) years. Eighty patients had no complications, and 38 had remote complications. The incidence of remote complications was the highest (54 percent at 5 years) for young patients with severe diverticulitis on computed tomography and the lowest (19 percent at 5 years) for older patients with mild disease. Young age and severe diverticulitis taken separately were both statistically significant factors of poor outcome (P = 0.007 and P = 0.003, respectively), although age was no longer significant after stratification for disease severity on computed tomography (P = 0.07). Twenty-four patients died. The cause of death was unrelated to diverticulitis in 21 cases and unknown in the remaining 3. CONCLUSIONS: We propose that after a first acute episode of diverticulitis treated nonoperatively, elective colectomy should be offered to young patients (! 50 years old) with severe diverticulitis on computed tomography.