Inflammatory aneurysms of the abdominal aorta

The so-called "inflammatory" aneurysm of the aorta of the abdominal wall is a special form of the arteriosclerotic aneurysm of the aorta observed in 5-15% of the abdominal aorta aneurysms. It is characterized by more or less marked periaortal fibrotization. The pathological correlate is represented by lymphocytous and plasmacellular infiltrates that are mainly seen and identified in the region of the adventitia. The etiology has not yet been clarified. Since surgery of the inflammatory aneurysm of the abdominal wall aorta is rendered difficult due to neighbouring organs (e.g. ureters) becoming callous and adhesive, safe preoperative diagnosis is desirable. Suspicion of an aneurysm of the abdominal wall can be fairly safely confirmed by sonography. In case of a partially thrombotic aneurysm a characteristic fourfold stratification can be seen: free lumen/thrombus/calcified wall of aorta/law-echo outer layer. This last-named layer--the "inflammatory" portion--is tapelike, semicircular and more or less strongly developed. The inflammatory aneurysm of the abdominal wall is often symptomatic. Hence, the most important differential diagnosis concerns the covered perforation and the dissecting aortic aneurysm, as well as Ormond's disease, periaortal lymphomas and other retroperitoneal tumours.