Postoperative Outcomes of Patients With Nonperforated Gangrenous Appendicitis: A National Multicenter Prospective Cohort Analysis.

BACKGROUND: Controversy exists regarding the use of postoperative antibiotics for nonperforated gangrenous appendicitis. OBJECTIVE: The aim of this study was to evaluate the rate of postoperative infectious complications and the effect of postoperative antibiotic use among patients with nonperforated gangrenous appendicitis. DESIGN: This was a prospective cohort study conducted during 2 months. SETTINGS: A national multicenter observational study was conducted in 62 Dutch hospitals. PATIENTS: All of the consecutive patients who had surgery for suspected acute appendicitis were included. Patients were excluded if no appendectomy was performed or appendectomy was performed for pathology other than acute appendicitis. MAIN OUTCOMES MEASURES: Type of appendicitis was categorized as phlegmonous, gangrenous, or perforated. The primary end point was the rate of infectious complications (intra-abdominal abscess and surgical site infection) within 30 days after appendectomy. Univariable and multivariable logistic regression analyses were performed to identify predictors of infectious complications. RESULTS: A total of 1863 patients were included: 1321 (70.9%) with phlegmonous appendicitis, 181 (9.7%) with gangrenous appendicitis, and 361 (19.4%) with perforated appendicitis. Infectious complications were more frequent in patients with gangrenous versus phlegmonous appendicitis (7.2% vs 3.8%; p = 0.03). This association was no longer statistically significant in multivariable analysis (OR = 1.09 (95% CI, 0.49-2.44)). There was no significant difference in infectious complications between <= 24 hours (n = 57) of postoperative antibiotics compared with >24 hours (n = 124; 3.6% vs 8.9%; p = 0.35) in patients with gangrenous appendicitis. LIMITATIONS: Possible interobserver variability in the intraoperative classification of appendicitis was a study limitation. CONCLUSIONS: Patients with nonperforated gangrenous appendicitis are at higher risk of infectious complications than patients with phlegmonous appendicitis, yet gangrenous disease is not an independent risk factor. Postoperative antibiotic use over 24 hours was not associated with decreased infectious complications. See Video Abstract at http://links.lww.com/DCR/A1000.