Endoscopic retrograde appendicitis therapy versus sub-endoscopic retrograde appendicitis therapy for acute appendicitis: a retrospective observational cohort study

BACKGROUND: Acute appendicitis is a common acute abdominal emergency. Laparoscopic appendectomy (LA) carries risks such as bleeding, infection, and negative procedures. Endoscopic retrograde appendicitis therapy (ERAT) is minimally invasive but cannot directly visualize the appendiceal cavity. The novel eyeMax disposable biliary imaging system enables direct observation of the appendix cavity during sub-endoscopic retrograde appendicitis therapy (SERAT), overcoming key limitations of ERAT. The aim of this study is to compare the effectiveness and clinical outcomes of ERAT with SERAT in treating acute appendicitis. METHOD: This retrospective study analyzed 60 patients undergoing ERAT and 97 undergoing SERAT for acute appendicitis at Shandong Provincial Third Hospital, China, from November 2021 to September 2024. Propensity score matching (PSM, 1:1) was performed to balance baseline characteristics, yielding 55 pairs of patients. Baseline data, procedural indicators, short-term recovery, and long-term recurrence were compared. RESULTS: Baseline characteristics were generally comparable between the two groups before and after PSM. After matching, SERAT was associated with significantly shorter operation time and intubation time than ERAT (24.69 vs. 42.65 min, P < 0.001; 96.38 vs. 241.38 s, P < 0.001). The technical success rate was significantly higher in the SERAT group than in the ERAT group (53/55 vs. 47/55, P = 0.047). No significant differences were found in fecalith removal, 6-hour VAS score, hospital stay, or hospitalization cost. Direct visualization in the SERAT group showed inner-wall congestion and edema in 100% of cases, intracavitary fecaliths in 54.4%, and intraluminal pus in 89%. During follow-up, recurrence-free survival was significantly better in the SERAT group ( P = 0.036). Among patients with follow-up data, recurrence occurred in 3/55 (5.4%) patients in the SERAT group and 11/55(20%) patients in the ERAT group. No long-term adverse events were observed in either group. CONCLUSION: SERAT is an effective and safe approach for the diagnosis and treatment of acute appendicitis, offering shorter operation and intubation times, a lower recurrence rate, and minimally invasive treatment.