Inflammatory aneurysm in the infrarenal portion of thoracoabdominal aneurysms: an uncommon variant.
We present an unusual variant of type IV thoracoabdominal aneurysm with inflammatory changes in part of the aortic wall. Between January 1990 and December 2000, 5 male patients (mean age, 68 years) with inflammatory aneurysms of 29 with type IV thoracoabdominal aneurysms (17.2%) underwent surgery. All five had arterial hypertension. The diagnosis of inflammatory aneurysm was made on the basis of clinical suspicion supported by characteristic features on CT scans. Endoaneurysmorraphy was performed in all cases; a tube graft was inserted in three cases, and bifurcation was performed in 2. The macroscopic appearance of periaortic fibrosis was detected at the infrarrenal portion of the aneurysm in the 5 patients, but no retroperitoneal fibrosis was found at the level of the distal thoracic aorta in any case. There was no operative mortality. Paraparesis was not detected in any patient. One patient had acute kidney failure, and another required an extended stay in the intensive care unit because of respiratory insufficiency. Pathologic examination confirmed the diagnosis of inflammatory aneurysm in all 5 patients, with characteristic adventitial thickening caused by lymphoplasmacytic infiltrate and fibrosis around the ganglionic and nerve structures. Type IV thoracoabdominal aneurysm with inflammatory changes can be treated at surgery with a retroperitoneal approach. Usually the fibrotic response is confined to the infrarenal portion of the aneurysm.