S6060 A Hidden Culprit: Undiagnosed Chronic Appendicitis Cause of Small Bowel Obstruction

Introduction: Chronic appendicitis is a rare and difficult diagnosis and an even rarer cause of small bowel obstruction (SBO). It is thought that persistent partial obstruction of the appendix leads to inflammation. Difficulty in diagnosis occurs due to atypical and vague symptoms such as constant abdominal pain that can last over months or years, chest pain, and early satiety. SBO as the initial presenting sign of chronic appendicitis is a rare phenomenon. SBOs usually occur in patients with prior history of abdominal surgeries, neoplasms, or intestinal disease. In our case, the patient does not have prior surgical or gastrointestinal history and represents a rare case of chronic appendicitis causing SBO. Case Description/Methods: A 70-year-old man with history of hypertension, hyperlipidemia, diabetes mellitus, and chronic kidney disease presented with 2 day history of intermittent chest tightness worse with food intake. He denies nausea, vomiting, or prior abdominal surgeries. Vitals were normal on presentation, and the examination was remarkable for abdominal distention. Laboratory data and cardiac work up including cardiac enzymes, electrocardiogram, and echo were unremarkable. Computed tomography of the abdomen and pelvis showed multiple air fluid levels consistent with small bowel obstruction with a transition point at distal ileum. Surgery was consulted immediately and exploratory laparotomy revealed the chronic scar tissue and adhesive bands in the last 10 cm of the terminal ileum, cecum, and appendix. Patient underwent an appendectomy and had lysis of his adhesions. Pathology of appendix and scar tissue revealed fibrous adhesions with nonspecific reactive changes but were negative for malignancy or appendiceal fecalith. Discussion: Inflammation of the appendix can lead to adherence to surrounding structures due to mobility of appendix. This chronic inflammation can lead to adhesion in the bowel proximally like our patient who developed adhesions to the terminal ileum and cecum. With atypical symptom presentation and difficulty with diagnosis, chronic appendicitis is a rare condition with less than 2 percent of cases of appendicitis being chronic. Our case is even rarer as patient did not have constant abdominal pain over a long period of time but instead had chest pain and small bowel obstruction. Most cases of chronic appendicitis are subclinical or resolve spontaneously therefore our case is an extremely rare presentation. With difficulty of diagnosis, a surgical and pathological diagnosis is required for chronic appendicitis.