Percutaneous abscess drainage in patients with perforated acute appendicitis: effectiveness, safety, and prediction of outcome.

OBJECTIVE: The purposes of this study were to retrospectively investigate the effectiveness and safety of CT-guided percutaneous drainage in the treatment of patients with acute appendicitis complicated by perforation and to identify CT findings and procedure-related factors predictive of clinical and procedure outcome.
MATERIALS AND METHODS: From March 2005 through December 2008, 41 consecutively registered patients (24 men, 17 women; age range, 18-75 years) underwent CT-guided percutaneous drainage for the management of acute appendicitis complicated by perforation and abscess. Three board-certified radiologists independently reviewed preprocedure CT images. Patients were assigned to one of three risk categories on the basis of the CT findings. Success and failure of percutaneous drainage were defined on a per-patient (i.e., clinical outcome) and per-procedure (i.e., technical outcome) basis. Immediate, periprocedure, and delayed complications were recorded. The association between candidate predictive variables, including demographic characteristics, preprocedure CT findings, and procedure-related factors and clinical or technical outcome was assessed with logistic regression models.
RESULTS: Fifty-two CT-guided procedures were performed on 41 patients. Percutaneous drainage had clinical and technical success rates of 90% (37 of 41 patients, 47 of 52 procedures) with no procedure-related complications. In seven patients (19%) clinical success required repeated drainage procedures. A large, poorly defined periappendiceal abscess and an extraluminal appendicolith on preprocedure CT images were independent predictors of clinical failure of percutaneous drainage.
CONCLUSION: CT-guided percutaneous drainage is both effective and safe in the treatment of patients with acute appendicitis complicated by perforation and abscess. The clinical and technical success rates are high.