[A clinicopathological study of ruptured infectious aneurysms]

We investigated 952 consecutive autopsy cases between January 1990 and May 1994 to identify ruptured infectious aneurysms (IAs) of the aorta or iliac artery. Twenty patients (2.1%) died of artrial rupture, including 9 men and 11 women. The cause of rupture was IA in four cases (0.42%), atherosclerotic aneurysm (AA) in nine (0.95%), dissection (D) in six (0.63%), and aortoenteric fistula due to irradiation in one (0.11%). Infection of pre-existing aneurysms was considered to be AA rather than IA and the patient with aorto-enteric fistula was excluded from the study. Patients with IA were significantly older than other patients (IA: 85.8 +/- 4.3, AA: 80.2 +/- 4.1, and D: 77.7 +/- 5.0 years old), and were less frequently accompanied by leukocytosis than patients with AA, although this difference was not significant (11,100 vs 13,000). The four patients with IA consisted of one man and three women, all of whom died suddenly. Two patients had perforation in the atherosclerotic descending aorta and the other two had perforation in the atherosclerotic common iliac artery. Histological examinations revealed marked neutrophilic infiltration in all four cases, and bacterial colonies in three cases. In conclusion, IAs were not rare. Since they often cause sudden death, special attention should be given to elderly patients who develop infection.