Partial Situs Inversus Complicating the Surgical and Diagnostic Course of a Duodenal Switch Revision: A Case Report

Situs inversus is a rare congenital disorder of left-right organ orientation characterized by mirror-image transposition of some or all visceral structures. While situs inversus totalis involves the transposition of both thoracic and abdominal organs, partial situs inversus involves only a subset of organs. The condition is frequently asymptomatic but can complicate diagnostic evaluation and surgical management when anatomic relationships differ from expected landmarks. We present a 44-year-old woman with known partial situs inversus involving the intestinal tract, without the transposition of the major thoracic or abdominal organs, and a history of duodenal switch bariatric surgery. Her postoperative course was complicated by small bowel obstruction, intra-abdominal abscesses, bowel perforation, enterocutaneous fistula formation, and polymicrobial infection requiring multiple operative and percutaneous interventions. She underwent two exploratory laparotomies and abdominal washout procedures, including the revision of her duodenal ileostomy, the extensive lysis of adhesions, and appendectomy. Her subsequent management involved multiple drain placements, prolonged antimicrobial therapy, nutritional support, and the management of a persistent right-sided abdominal drain with biliary output concerning for a duodenocutaneous fistula. During her prolonged course, the recognition of her altered intestinal anatomy remained an important consideration in her complex postoperative management. Although the severity of her postoperative complications cannot be attributed directly to situs inversus, the condition added complexity to an already challenging revisional surgical course. This case highlights the importance of recognizing and clearly documenting altered intestinal anatomy throughout prolonged, multi-stage abdominal surgical care.