Successful Endoscopic Retrograde Appendicitis Therapy in a Patient With Situs Inversus Totalis: A Case Report and Technical Considerations

CASE REPORT A 61-year-old man presented with a 2-day history of intermittent abdominal pain and bloating. Physical examination revealed left lower quadrant tenderness at the mirror image of the McBurney point. Laboratory tests showed elevated C-reactive protein (17.22 mg/L). Abdominal computed tomography demonstrated situs inversus totalis (SIT) with a mildly thickened appendix (0.7 cm) in the left lower quadrant (Figure 1). Based on these findings, acute appendicitis was diagnosed. Endoscopic retrograde appendicitis therapy (ERAT) was performed under colonoscopic guidance. Colonoscopy confirmed the preoperative computed tomography findings, revealing a left-sided cecum and appendiceal orifice consistent with SIT. Using a transparent cap, the appendiceal orifice was successfully cannulated with a stone retrieval basket. The appendiceal lumen was irrigated until clear, with drainage of inflammatory debris (Video 1). The procedure was technically straightforward, comparable to ERAT in normal anatomy, with no immediate complications. Postprocedure, the patient's abdominal pain resolved, and C-reactive protein normalized to 8 mg/L within 2 days. He was discharged on postoperative day 3 and remained asymptomatic without recurrence at 1-year follow-up. {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 1","caption":"Endoscopic retrograde appendicitis therapy (ERAT) in a patient with situs inversus totalis (SIT). Colonoscopy confirms a left-sided cecum and appendiceal orifice. Using a transparent cap, the appendiceal orifice is cannulated with a stone retrieval basket, followed by irrigation and drainage of inflammatory debris.","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_98wkk57q"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} Figure 1.: Abdominal computed tomography scan showing situs inversus totalis. The appendix (arrow) is located in the left lower quadrant.SIT occurs in 1:5,000-10,000 live births.1 The incidence of appendicitis in SIT is 0.016%–0.024%.2 Reports of ERAT in SIT are scarce. While laparoscopic surgery requires adaptation to mirror-image anatomy,2–4 ERAT, as a natural orifice transluminal endoscopic surgery procedure, bypasses this challenge. This case demonstrates that ERAT is technically feasible in SIT, unaffected by the mirror arrangement of abdominal organs. ERAT offers the potential advantage of appendiceal preservation, which may theoretically maintain immune function, though further studies are needed.5 This video provides a visual guide for endoscopists encountering similar anatomical variations, demonstrating that ERAT can be performed safely without modification of standard techniques. DISCLOSURES Author contributions: Q. Zhou: Drafted the manuscript, literature review, figure preparation; Q. Shen: Performed the ERAT procedure, conceptualized the case report, revised the manuscript; Z. Liu: Assisted in the ERAT procedure, collected clinical data; X. Liu: Provided patient care, collected follow-up data. Q. Shen is the article guarantor. Financial disclosure: The authors declare no conflicts of interest. Informed consent was obtained for this case report.