Inflammatory Abdominal Aortic Aneurysm in which Retroperitoneal Thickening Improved One Year after Endovascular Aortic Repair

Abstract

A 70-year-old man who underwent computed tomography (CT) for persistent abdominal pain was found to have an abdominal aortic aneurysm, and he was referred to our hospital with suspected threatened rupture. CT showed an abdominal aortic aneurysm with a maximum short diameter of 60 mm below the renal artery, and the retroperitoneum around the aneurysm was thickened and contrast-enhanced (mantle sign). Blood tests showed elevated C-reactive protein, but procalcitonin was negative, and immunoglobulin G4 was not elevated. Blood culture was negative, and an inflammatory abdominal aortic aneurysm was diagnosed. Endovascular aortic repair was performed. The patient's postoperative course was uneventful and he was discharged on Day 6. Since hydronephrosis and similar comorbidities were not present, steroid treatment was not administered, and the patient was kept under observation. Six months after surgery, the inflammatory response (CRP) had decreased to 0.4 mg/dl, but there was no change in aneurysm diameter or retroperitoneal thickening. Follow-up without steroid treatment continued, and the thickening of the retroperitoneal wall eventually decreased one year postoperatively.