Fig. 1

Procedures of endoscopic retrograde appendicitis therapy (ERAT). a Congestion and edema around the mucosa of appendix orifice. b The endoscopic retrograde appendicography (ERA) fluoroscopy showed filling defect in the appendix lumen (arrows), which indicated the presence of appendicoliths. c Cannulation of catheter along the guidewire with sand-like appendicoliths excretion and pus drainage inside the appendix lumen, confirming acute appendicitis. d Retracting the appendicoliths by the extraction basket. e After appendicolith being retracted, the appendix lumen was fully filled with contrast media under ERA. f Stenting for keeping pus drainage