An infected aneurysm is an

aneurysm An aneurysm is an outward :wikt:bulge, bulging, likened to a bubble or balloon, caused by a localized, abnormal, weak spot on a blood vessel wall. Aneurysms may be a result of a hereditary condition or an acquired disease. Aneurysms can also b ...

arising from bacterial infection of the arterial wall. It can be a common complication of the hematogenous spread of bacterial infection.

Cause

Intracranial mycotic aneurysms (ICMAs) complicate about 2% to 3% of infective

endocarditis Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves. Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, o ...

(IE) cases, although as many as 15% to 29% of patients with IE have neurologic symptoms. ''Staphylococcus'' and ''Salmonella'' spp are the most common organisms that cause mycotic aneurysms. Anaerobic bacteria such as ''Bacteroides'', and ''Clostridium'' spp can also cause mycotic aneurysms.

Treatment

Mycotic abdominal aorta aneurysm (MAAA) is a rare and life-threatening condition. Because of its rarity, there is a lack of adequately powered studies and consensus on its treatment and follow up. A management protocol on the management of mycotic abdominal aortic aneurysm was recently published in the Annals of Vascular Surgery by Premnath et al.

History

William Osler Sir William Osler, 1st Baronet, (; July 12, 1849 – December 29, 1919) was a Canadian physician and one of the "Big Four" founding professors of Johns Hopkins Hospital. Osler created the first Residency (medicine), residency program for speci ...

first used the term "mycotic aneurysm" in 1885 to describe a mushroom-shaped aneurysm in a patient with subacute bacterial

. This may create considerable confusion, since "mycotic" is typically used to define fungal infections. However, mycotic aneurysm is still used for all extracardiac or intracardiac aneurysms caused by infections, except for syphilitic aortitis.Bayer AS, Scheld WM. Endocarditis and intravascular infections. In: Mandell GL, Bennett JE, Dolin R, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 5th ed. Philadelphia: Churchill Livingstone; 2000:888-892. The term "infected aneurysm" proposed by Jarrett and associatesJarrett F, Darling RC, Mundth ED, Austen WG. Experience with infected aneurysms of the abdominal aorta. Arch Surg. 1975;110:1281-1286. is more appropriate, since few infections involve

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

.Mycotic (Infected) Aneurysm Caused by Streptococcus pneumoniae. Khosrow Afsari, et al. Infect Med. 2001;18(6)　http://www.medscape.com/viewarticle/410168 According to some authors, a more accurate term might have been endovascular infection or infective

vasculitis Vasculitis is a group of disorders that destroy blood vessels by inflammation. Both artery, arteries and veins are affected. Lymphangitis (inflammation of lymphatic vessels) is sometimes considered a type of vasculitis. Vasculitis is primarily c ...

, because mycotic aneurysms are not due to a fungal organism.

Complications

Mycotic aneurysms account for 2.6% of aortic aneurysms. For the clinician, early diagnosis is the cornerstone of effective treatment. Without medical or surgical management, catastrophic hemorrhage or uncontrolled

sepsis Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage of sepsis is followed by suppression of the immune system. Common signs and s ...

may occur. However, symptomatology is frequently nonspecific during the early stages, so a high index of suspicion is required to make the diagnosis.

References

{{DEFAULTSORT:Mycotic Aneurysm Neurology Infectious diseases