Determination of risk factors for conversion from laparoscopic to open appendectomy in patients with acute appendicitis

BACKGROUND: Acute appendicitis is the most common cause of surgical emergencies. It can be difficult to distinguish cases of acute appendicitis that should be managed by laparoscopic appendectomy (LA) from those that should be managed by open surgery. This study aimed to prevent the inappropriate choice of technique and associated complications by identifying potential risk factors for conversion from laparoscopic to open appendectomy (OA) at the time of initial surgical assessment. METHODS: This is a retrospective analysis of patients who underwent laparoscopic exploration for acute appendicitis. The study included patients over 18 years of age between January 2016 and July 2021. Patients were divided into two groups according to the surgical approach: those who underwent a LA and those who initially underwent laparoscopic exploration first and then converted to OA. Demographics, perioperative factors, and outcomes were compared between groups. RESULTS: The study included 634 adults undergoing laparoscopic exploration for an appendectomy. About 80.8% had LA, and 19.2% (n=122) required COA. COA patients’ average age was significantly higher than LA patients’ (48.5 years vs. 37.8 years, P<0.001). The conversion rate for patients over 65 was 63.8%, compared to 15.6% for those under 65 (P<0.001). COA patients had higher bilirubin levels (36.1% vs. 13.5%, P<0.001), higher American Society of Anesthesiologists (ASA) scores (ASA >2, COA 52.5% vs. LA 7.8%, P<0.001), and a higher need for CT imaging (84.4% vs. 67.6%, P<0.001) than LA patients. An Alvarado score >6 significantly differentiated LA from COA (62.6% vs. 39.4%, P< p<0.001). COA patients experienced significantly increased periods until starting oral intake (31.6 vs. 9.9 h, P<0.001) and higher rates of complicated appendicitis (40.9% vs. 0.6%, P<0.001). After surgery, COA had higher rates of complications compared to LA: surgical site infections (8.2% vs. 2.7%, P=0.004), reoperation (13.1% vs. 0%, P<0.001), hospital readmission (14.7% vs. 2.3%, P<0.001), and mortality (1.6% vs. 0%, P<0.004). CONCLUSION: Advanced age, especially over 65 years, elevated bilirubin levels, an ASA >2 score, and an increased need for preoperative diagnostics using CT scans were found to be significant predictors of conversion to OA. In the conversion group, operative time, time to oral intake, and the incidence of complicated appendicitis were significantly higher. The conversion group had significantly higher rates of postoperative complications, surgical site infections, hospital readmissions, and mortality. To avoid the increased rate of complications associated with conversion to open surgery, the initial evaluation of a patient with prospective risk factors may be beneficial.