Emphysematous Abdominal Aortic Aneurysm by Clostridium septicum with Synchronous Colon Cancer

Introduction: Clostridium septicum (C. septicum) aortitis is a rare condition frequently associated with colon adenocarcinoma and carries a poor prognosis. Case Report: We report the case of an 80-year-old man who was waiting for an elective endovascular repair of an abdominal aortic aneurysm (AAA) with a diameter of 5.8 × 5.4 cm. He underwent a colonoscopy because of a thickening of the colon wall in the preoperatory CT. One week after that, he presented at the emergency with a 48-hour duration of fever and abdominal pain. Abdominal CT imaging revealed an increased aneurysm size to 6.1 × 6.6 cm including gas within the aorta. Treatment consisted of antibiotics, urgent axillar to femoro-femoral bypass, excision and ligation of the infrarenal aorta and right hemicolectomy with end-ileostomy. Aortic cultures were positive for C. septicum. The postoperative was complicated by renal failure and the patient died. Conclusion: C. septicum-infected aortic aneurysm is a rare entity that is strongly associated with colon cancer. The presence of gas within the aorta or emphysematous aortitis is the most common sign of C. septicum infection. Broad-spectrum antibiotics should be initiated and emergency surgical management with excision of the infected aneurysm and grafting is required.