Infected thoracoabdominal aortic aneurysm related to an implanted long-term arterial catheter for chemotherapy: a case report

Background An infected aortic aneurysm is a rare and life-threatening vascular condition with a high incidence of arterial rupture and recurrence even after treatment. One of the most common causes of an infected aortic aneurysm is catheter-related bloodstream infection. Although infection due to indwelling catheters is possible, the incidence of this is rare, especially for long-term implanted arterial catheters. Case presentation A 78-year-old Japanese man with a past medical history of rectal cancer with metastasis to the liver presented to our hospital as a result of low back pain. Remission had been achieved following surgery and adjuvant chemotherapy via an implanted catheter for arterial infusion. However, the original catheter that was inserted from the femoral artery to the hepatic artery via the celiac artery was still present more than 10 years after diagnosis, without being replaced, in case of a recurrence. On the day of admission, computed tomography scan of the chest and abdomen with contrast revealed an irregularly shaped aortic aneurysm at the origin of the celiac artery and a partially expanded common hepatic artery with disproportionate fat stranding along the implanted arterial catheter without extravasation. Although the initial impression was an impending rupture of the acute thoracoabdominal aortic aneurysm, a catheter-related infection was considered as a differential diagnosis. Surgery was performed, which revealed a catheter-related infected aortic aneurysm based on images along the catheter, pus cultures, and tissue pathology examination results. Conclusions This is an extremely rare case of an infectious aneurysm caused by prolonged implantation of an arterial catheter for chemotherapy. It should be noted that an indwelling arterial catheter not only causes bloodstream infections but can also cause an infection of a thoracoabdominal aortic aneurysm.