Mycotic aneurysm

A mycotic aneurysm, also called an infected aneurysm, is an aneurysm that arises when bacteria infect the wall of an artery, often by spreading through the blood. Intracranial forms complicate roughly 2 to 3 percent of infective endocarditis cases, and Staphylococcus and Salmonella are the commonest organisms behind those of the aorta, with anaerobes and occasionally tuberculosis also involved. William Osler introduced the term in 1885 for a mushroom-shaped aneurysm in a patient with bacterial endocarditis, although the name is misleading because few such aneurysms involve fungi. Symptoms are often vague early on, so early diagnosis matters, since untreated cases can end in catastrophic bleeding or uncontrolled sepsis. Mycotic aneurysms make up about 2.6 percent of aortic aneurysms.