Clinical significance of peri-appendiceal abscess and phlegmon in acute complicated appendicitis patients undergoing emergency appendectomy

BACKGROUND Although antibiotic therapy has become the primary treatment for acute unco-mplicated appendicitis,the management of acute complicated appendicitis nece-ssitates careful consideration of various treatment options.AIM To analyze the clinical data of patients who underwent emergency appendectomy for acute complicated appendicitis with peri-appendiceal abscess or phlegmon,identify factors influencing the postoperative length of hospital stay(LOS),and improve treatment strategies.METHODS The clinical data of acute complicated appendicitis patients with peri-appendiceal abscess or phlegmon who underwent emergency appendectomy at The Depart-ment of Emergency Surgery,Zhongshan Hospital,Fudan University from January 2016 to March 2023 were retrospectively analyzed.RESULTS A total of 234 patients were included in our study.The duration of symptoms and the presence of an appendicolith were significantly correlated with the occurrence of peri-appendiceal abscess in patients with acute complicated appendicitis(P<0.001 and P=0.015,respectively).Patients with symptoms lasting longer than 72 h had a significantly longer postoperative LOS compared to those with symptoms lasting 72 h or less[hazard ratio(HR),1.208;95%CI:1.107-1.319;P<0.001].Additionally,patients with peri-appendiceal abscesses had a significantly longer postoperative LOS compared to those with phlegmon(HR,1.217;95%CI:1.095-1.352;P<0.001).The patients with peri-appendiceal abscesses were divided into two groups based on the median size of the abscess:Those with abscesses smaller than 5.0 cm(n=69)and those with abscesses 5.0 cm or larger(n=82).Patients with peri-appendiceal abscesses measuring 5.0 cm or larger had a significantly longer postoperative LOS than those with abscesses smaller than 5.0 cm(P=0.038).CONCLUSION The duration of symptoms and the presence of an appendicolith are significant risk factors for the formation of peri-appendiceal abscesses in patients with acute complicated appendicitis.Patients with peri-appendiceal abscesses experience a significantly longer postoperative LOS compared to those with peri-appendiceal phlegmon.