Laparoscopic Procedure is Not Independently Associated with the Development of Intra-Abdominal Abscess after Appendectomy: A Multicenter Cohort Study with Propensity Score Matching Analysis

Aim: The aim of this study was to identify independent risk factors for postoperative intra-abdominal abscess (IAA) after appendectomy for patients with acute appendicitis. Backgraound: Although laparoscopic appendectomy (LA) has been performed universally, whether LA is associated with an increased incidence of postoperative IAA compared with open appendectomy (OA) remains controversial, which causes some surgeons' increasing concerns. Methods: We retrospectively analyzed 6805 consecutive adult patients with acute appendicitis who underwent LA or OA at 7 general hospitals in China. Patient characteristics, operative variables, and surgical outcomes were collected and compared between patients who underwent LA and OA. Propensity score matching analysis was used to minimize the bias in patient selection differing from various procedure of appendectomy. Independent risk factors associated with the development of postoperative IAA after appendectomy were identified by univariate and multivariate logistic regression analysis in the propensity matched cohort. Results: Over a 3-year period, 2710 (39.8%) and 4095 (60.2%) patients underwent LA and OA respectively. Patients who underwent OA had more males, American Society of Anesthesiologists score 2-3, preoperative systemic inflammatory response syndrome, and perforated appendicitis than those who underwent LA (all P<0.01). Propensity score matched analysis created 2542 pairs of patients. Univariate analysis revealed that patients who underwent LA had a higher incidence of postoperative IAA than patients who underwent OA (6.7% vs. 5.3%; P=0.039). However, multivariate logistic regression analysis identified LA not to be an independent risk factor associated with the development of postoperative IAA (odds ratio, 1.053; 95% confidence interval, 0.922-1.657; P=0.216). Conclusions: The present study identified that laparoscopic procedure was not an independent risk factor associated with the development of postoperative IAA after appendectomy of acute appendicitis. Therefore, concerns of increased incidence of IAA because of laparoscopic procedure are unwarranted.