eP459 - Robotic Management of Appendiceal-Sigmoid Fistula

Purpose/Background: Appendicitis is a common condition encountered by surgeons worldwide. Although typically uncomplicated, appendicitis can lead to complex scenarios. A fistula involving the appendix is a rare complication of appendicitis. An appendiceal-sigmoid fistula is a much less common phenomenon. In a 2020 systematic review of appendiceal fistulas, only 10 published cases of fistula formation to the sigmoid colon were identified. While there are few case reports documenting this pathology, none describe management using a robotic approach. We report a case of complicated appendicitis, perihepatic abscess, and appendiceal-sigmoid fistula treated with an interval robotic appendectomy and primary repair of colonic fistula. This is the first reported case of a robotic repair for an appendiceal-sigmoid fistula.Methods/Interventions: Our patient is a 56 year old male who presented after a syncopal episode. He was found to have Bacteroides fragilis and E. coli growth on blood culture. Computed tomography showed a complex mass of the ascending colon and perihepatic abscess. The appendix was not readily visualized on the initial CT. MRI demonstrated a colocolic fistula from the cecum to the sigmoid colon, with concerns for possible Crohn’s disease. He was treated with antibiotics and percutaneous drain of the perihepatic abscess. The patient progressed well and was discharged home. A colonoscopy revealed a sigmoid fistula. After several months, he underwent an interval robotic appendectomy, appendiceal-sigmoid fistula takedown, and primary repair of the sigmoid colon.Results/Outcomes: The patient tolerated the procedure well and his postoperative course was uneventful. He was discharged home the day after surgery. Final pathology demonstrated acute and chronic inflammation on the periappendiceal soft tissue, negative for malignancy.Conclusion/

Discussion: Development of a fistula from the appendix to the sigmoid colon is a rare complication of appendicitis. Preoperative evaluation involves fistula localization and determining the etiology, which may include appendicitis, diverticulitis, infection, inflammatory bowel disease, neoplasm, trauma or congenital abnormality. Surgical treatment is determined by the structures involved and underlying pathology. This patient was found to have appendicitis complicated by formation of a perihepatic abscess and fistula formation to the sigmoid colon. A robotic assisted approach is a viable and safe option for management of benign appendiceal-sigmoid fistula.Robotic Treatment of Appendiceal-Sigmoid FistulaA-CT with yellow arrows indicating the fistula. B and C- Fistula from the appendix to the sigmoid colon. D- Stapled transection of the appendix base. E- Arrow to the sigmoid colon fistula defect. F- Primary repair of the sigmoid colon.