SP2.1 - Endoscopic retrograde appendicitis therapy for peri-appendiceal abscess

Abstract Aims ERAT is a novel technique primarily for uncomplicated appendicitis, but it is starting to be used also for peri-appendiceal abscesses. The aim of this study was to evaluate the efficacy and clinical outcomes of ERAT in treating patients with peri-appendiceal abscess. Methods Between January 2018 and April 2023, twenty-eight patients with peri-appendiceal abscess were treated with ERAT. We retrospectively analyzed the location and size of the peri-appendiceal abscess, success rate of ERAT, median operative time, postoperative hospital stay and complications. We defined success of ERAT as finding the appendiceal orifice and successful performance of ERAT without conversion to appendectomy or percutaneous drainage of the appendiceal abscess within one month. All patients were followed up at least 6 months, with a median follow-up of 31.5 months. Results The success rate of ERAT was 75.0% (95% CI, 54.8%-88.6%; n = 21/28). 35.7% (95% CI, 19.3%-55.9%; n = 10/28) of peri-appendiceal abscesses were located in the lower ileum, and the median size of appendiceal abscesses was 43.5 mm (95% CI: 33-53). 80.8% (95% CI, 60.0%-92.7%; n = 21/26) of patients had a visual analogue scale pain score of ≤3 at 24 hours after treatment. The median procedure time was 69.5 minutes (95% CI: 51-76), and the median hospital stay was 6.5 days (95% CI: 5-9). During the follow-up period, a total of four (17.1%; 95% CI, 0.9%-13.1%; 4/21) patients presented with abdominal pain associated with peri-appendiceal abscesses. Conclusions ERAT is a technically feasible treatment for peri-appendiceal abscesses.