Background: As a classification of appendicitis, complicated appendicitis has no standardized treatment for adults.Method: According to the related literature systematically searched on PubMed, Embase, Cochrane and Web of Science, we evaluated the efficacy of surgical treatment and conservative treatment for complicated appendicitis, especially focused on the outcomes about the length of stay, operation time, postoperative complications and unplanned additional intervention, in the literature. Result: A total of 14 studies were involved in the meta-analysis, including 845 patients in the immediate operation group (IO) and 756 patients in the conservative management group (CM). Compared with conservative treatment, the total hospitalization time was reduced by 1 day (WMD=-1.29, 95%CI [-2.42, -0.16], P=0.03<0.05). The incidence of unplanned additional intervention in patients undergoing emergency surgery is lower than that of conservative treatment (OR=0.18, 95%CI [0.11, 0.30], P<0.00001). Surgical patients are more likely to have complications such as wound infection (OR=2.41, 95%CI [1.08, 5.38], P=0.03<0.05) and intestinal obstruction (OR=4.14, 95%CI [2.21, 7.75], P<0.00001) than conservative patients. The incidence of abdominal abscess was lower than that of conservative treatment, and the difference was not statistically significant (OR=0.9, 95%CI [0.54, 1.47], P=0.66>0.05). Conclusion: Compared with conservative management patients, immediately operated patients have shorter hospitalization time and less unplanned intervention, which can significantly reduce the readmission opportunity of patients with complicated appendicitis and lighten the burden of follow-up and medical resource consumption.

Abstract Background: As one of the classified groups of appendicitis, complicated appendicitis has no standardized treatment methods for adults.Method: The efficacy of surgical treatment and conservative treatment for complicated appendicitis was evaluated based on the literatures systematically searched on PubMed, Cochrane and Web of Science. A focus was given to important aspects, such as the outcomes of the length of stay, operation time, postoperative complications and unplanned additional interventions. Result: A total of 14 studies were involved in the meta-analysis, which included 845 patients in the immediate operation group (IO) and 756 patients in the conservative management group (CM). The total hospitalization time for patients with surgical treatment was decreased by 1 day (WMD= -1.29, 95% CI [-2.42, -0.16], P= 0.03< 0.05) compared to that of patients with conservative treatment. The incidence of unplanned additional interventions in patients who underwent emergency surgery is lower than that of patients with conservative treatment (OR=0.18, 95%CI [0.11, 0.30], P<0.00001). Compared to patients with conservative treatment, patients who received surgery are more likely to develop complications such as wound infection (OR=2.41, 95%CI [1.08, 5.38], P=0.03<0.05) and intestinal obstruction (OR=4.14, 95%CI [2.21, 7.75], P<0.00001). The incidence of abdominal abscess in patients with surgery treatment was lower than that of patients with conservative treatment, but the difference was not statistically significant (OR=0.9, 95%CI [0.54, 1.47], P=0.66>0.05). Conclusion: In treating complicated appendicitis, patients who received immediate operation, when compared to patients managed under conservative treatment, have shorter hospitalization time and less unplanned interventions; hence significantly reduce the likelihood of readmission. This can decrease the requirements for follow-up treatments and ultimately lower the consumption of medical resources.