An infected aneurysm[Lazar Greenfield, and Michael W. Mulholland. Greenfield's Surgery: Scientific Principles and Practice. Philadelphia: Wolters Kluwer Health/Nut Williams & Wilkins, 2011. Print. Page 1563] is an aneurysm 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 (IE) cases, although as many as 15% to 29% of patients with IE have neurologic symptoms.
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 first used the term "mycotic aneurysm" in 1885 to describe a mushroom-shaped aneurysm in a patient with subacute bacterial
endocarditis. 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 associates[Jarrett 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.[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, 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 may occur. However, symptomatology is frequently nonspecific during the early stages, so a high index of suspicion is required to make the diagnosis.
