Acute Colonic Diverticulitis : The role of computed tomography in primary diagnosis, prediction of complications and surgical intervention

The overall aim of this thesis was to expand the current knowledge regarding the advantages and limitations of computed tomography (CT) for patients with acute diverticulitis and evaluate outpatient treatment for uncomplicated diverticulitis. Paper I: A retrospective evaluation of 602 patients with reported uncomplicated diverticulitis. Scans were re-evaluated and the degree of inflammation was graded. Signs of complications or other diseases were also noted. No radiological findings on CT could predict the development of complications or recurrence in patients with uncomplicated diverticulitis. However, 44 patients (7.3%) had signs of complicated diverticulitis that had been overlooked on the initial assessment. Despite small complications and a non-antibiotic treatment, the majority of patients recovered without incident, further strengthening the non-antibiotic treatment strategy. Paper II: A retrospective analysis of conservative treatment for perforated diverticulitis (n = 136) during a 5-year period. Twenty-nine of 136 patients were operated on within 24 h and not candidates for conservative management. Patients more than 75 years old, immunosuppressed patients, patients with free intraperitoneal air or free fluid in the abdominal cavity were at higher risk for emergency surgery within the first 24 h. Conservative treatment was successful in 101 of 107 patients (94%) when attempted. The presence of simultaneous abscess increased the risk for conservative treatment failure. Paper III: The aim of this prospective study was to determine if a non-enhanced low-dose CT was as sensitive as standard CT with intravenous (IV) contrast for patients with suspected acute diverticulitis. The included patients underwent both types of CT examinations. CT images were graded by three independent radiologists for the presence of diverticulitis, complications or other findings that could explain the patient’s symptoms. Sensitivity, specificity and both intra- and inter-reader agreement for low-dose CT were very high. Therefore, we recommend this examination for suspected diverticulitis. Paper IV: In this prospective study, 155 consecutive patients with CT-verified acute uncomplicated diverticulitis were treated as outpatients without antibiotics. Overall, only four patients (2.6%) returned to the hospital because of treatment failure, all of whom were hospitalized and received antibiotics. Outpatient treatment of uncomplicated diverticulitis is safe and recommended in selected patients.