Surgical site infection after laparoscopic and open appendectomy: a multicenter large consecutive cohort study

Laparoscopic appendectomy (LA) has been rapidly applied worldwide recently. The issue of surgical site infection (SSI) after appendectomy needs to be re-investigated and analyzed along with this trend. This study aimed to identify risk factors of SSI after appendectomy in recent years. This retrospective study was conducted among patients with acute appendicitis who underwent either laparoscopic or open appendectomy (OA) at 7 general hospitals in China from 2010 to 2013. The incidence of SSI, classified as incisional SSI and organ/space SSI, was investigated. A multivariate logistic regression model was used to assess independent risk factors associated with overall, incisional, and organ/space SSI, respectively. Among 16,263 consecutive patients, 3,422 (21.0 %) and 12,841 (79.0 %) patients underwent LA and OA, respectively. The incidences of overall, incisional, and organ/space SSI were 6.2, 3.7, and 3.0 %, respectively. The proportion of LAs among both procedures increased yearly from 5.3 to 46.5 %, while the incidences of overall and incisional SSI after appendectomy simultaneously decreased yearly from 9.6 to 4.5 % and from 6.7 to 2.2 %, respectively. In comparison with OA, LA was associated with lower incidences of overall and incisional SSI (4.5 vs 6.7 %, P < 0.001; and 1.9 vs 4.2 %, P < 0.001), but a similar incidence of organ/space SSI (3.0 vs 3.0 %, P = 0.995). After multivariate logistic regression analyses were performed, LA was found to be independently associated with a decrease in development of overall SSI [odds ratio (95 % confidence interval) OR (95 % CI), 1.24 (1.03-1.70); P = 0.04] or incisional SSI [OR (95 % CI), 1.32 (1.10-1.68); P = 0.01]. With the increasing application trends of laparoscopic procedure, the incidence of SSI after appendectomy declined accordingly. Compared with OA, LA was independently associated with a significantly lower incidence of incisional SSI, but a similar incidence of organ/space SSI.