mycotic aneurysm


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aneurysm

 [an´u-rizm]
a sac formed by the localized dilatation of the wall of an artery, a vein, or the heart.
 Classification of aneurysms. All three tunica layers are involved in true aneurysms (fusiform and saccular). In false aneurysms, blood escapes between tunica layers and they separate. If the separation continues, a clot may form, resulting in a dissecting aneurysm. From Copstead and Banasik, 2000.
adj., adj aneurys´mal. The chief signs of an arterial aneurysm are the formation of a pulsating tumor, and often a bruit (aneurysmal bruit) heard over the swelling. Sometimes there are symptoms from pressure on contiguous parts.

The most common site for an arterial aneurysm is the abdominal aorta. A true aneurysm results from formation of a sac by the arterial wall with at least one unbroken layer. It is most often associated with atherosclerosis. A false aneurysm usually is caused by trauma. In this case, the wall of the blood vessel is ruptured and blood escapes into surrounding tissues and forms a clot. Because of pressure within the clot arising from the heart's contractions, the clot often pulsates against the examiner's hand as does a true aneurysm.

Although atherosclerosis is responsible for most arterial aneurysms, any injury to the middle or muscular layer of the arterial wall (tunica media) can predispose the vessel to stretching of the inner and outer layers of the artery and the formation of a sac. Other diseases that can lead to an aneurysm include syphilis, cystic medionecrosis, certain nonspecific inflammations, and congenital defects in the artery.

It is possible for a person to be unaware of a small aneurysm for years. About 80 per cent of all abdominal aneurysms are palpable and may be noticed on a routine physical examination. One should be particularly alert to the possibility of an aneurysm in persons with a history of cardiovascular disease, hypertension, or peripheral vascular disease.

Aneurysms tend to increase in size, presenting a problem of increasing pressure against adjacent tissues and organs and a danger of rupture. When an aneurysm ruptures, a critical situation ensues. The patient with a ruptured aortic aneurysm exhibits severe pain and blood loss, leading to shock. A ruptured cerebral aneurysm produces neurologic symptoms and can resemble the clinical picture of stroke syndrome.

Treatment of aneurysm depends on the vessel involved, size of the aneurysm, and general health status of the patient.
arteriosclerotic aneurysm an aneurysm arising in a large artery, most commonly the abdominal aorta, as a result of weakening of the wall in severe atherosclerosis; called also atherosclerotic aneurysm.
arteriovenous aneurysm an abnormal communication between an artery and a vein in which the blood flows directly into a neighboring vein or is carried into the vein by a connecting sac.
atherosclerotic aneurysm arteriosclerotic aneurysm.
bacterial aneurysm an infected aneurysm caused by bacteria.
berry aneurysm (brain aneurysm) a small saccular aneurysm of a cerebral artery, usually at the junction of vessels in the circle of Willis; such aneurysms frequently rupture, causing subarachnoid hemorrhage. Called also cerebral aneurysm.
cardiac aneurysm thinning and dilatation of a portion of the wall of the left ventricle, usually a consequence of myocardial infarction.
cerebral aneurysm berry aneurysm.
cirsoid aneurysm dilatation and tortuous lengthening of part of an artery; called also racemose aneurysm.
compound aneurysm one in which some of the layers of the wall of the vessel are ruptured and some merely dilated; called also mixed aneurysm.
dissecting aneurysm one resulting from hemorrhage that causes lengthwise splitting of the arterial wall, producing a tear in the inner wall (intima) and establishing communication with the lumen of the vessel. It usually affects the thoracic aorta (see aortic dissection) but can also occur in other large arteries. See illustration.
false aneurysm
one in which the entire wall is injured and the blood is contained by the surrounding tissues, with eventual formation of a sac communicating with the artery (or heart). See illustration.
fusiform aneurysm a spindle-shaped aneurysm; see illustration.
infected aneurysm one produced by growth of microorganisms (bacteria or fungi) in the vessel wall, or infection arising within a preexisting arteriosclerotic aneurysm.
mixed aneurysm compound aneurysm.
mycotic aneurysm an infected aneurysm caused by fungi.
racemose aneurysm cirsoid aneurysm.
saccular aneurysm (sacculated aneurysm) a saclike aneurysm; see illustration.
spurious aneurysm
false aneurysm (def. 1).
varicose aneurysm one formed by rupture of an aneurysm into a vein.

my·cot·ic an·eu·rysm

an aneurysm caused by the growth of fungi or bacteria within the vascular wall, usually following impaction of a septic embolus.

mycotic aneurysm

a localized dilation in the wall of a blood vessel caused by the growth of a fungus. It usually occurs as a complication of bacterial endocarditis. See also bacterial aneurysm.

mycotic aneurysm

An intravascular inflammatory response seen in 3-15% of Pts with infective endocarditis, which may arise from contiguous infected sites, but more commonly are of hematogenous spread, potentially resulting in thrombosis or rupture of arterial walls weakened by an inflamed vasa vasorum or by impaction-necrosis; because the vessels are a poor culture substrate for bacteria–eg,.S aureus, smaller MAs may resolve spontaneously; those ≥ 1-2 cm require excision if surgically accessible; of greatest concern are the cerebral aneurysms; sites of symptomatic MAs include sinus of Valsalva 25%, visceral arteries 24%, extremities 22%, brain 15%. Cf Berry aneurysm.

my·cot·ic an·eu·rysm

(mī-kot'ik an'yūr-izm)
An aneurysm caused by the growth of fungi within the vascular wall, usually following impaction of a septic embolus; also used to refer to the growth of bacteria within the vascular wall of an aneurysm; may result from impaction of septic embolus or from primary infection of the vessel wall.

aneurysm

a sac formed by the localized dilatation of the wall of an artery, vein or the heart.

aortic aneurysm
see aortic aneurysm.
arteriovenous aneurysm
an abnormal communication between an artery and a vein in which the blood flows directly into a neighboring vein or is carried into the vein by a connecting sac.
atherosclerotic aneurysm
one arising as a result of weakening of the tunica media in severe atherosclerosis.
bacterial aneurysm
an infected aneurysm caused by bacteria.
berry aneurysm
a small saccular aneurysm of a cerebral artery, usually at the junction of vessels in the circle of Willis; such aneurysms frequently rupture, causing subarachnoid hemorrhage. Called also brain aneurysm.
cardiac aneurysm
thinning and dilatation of a portion of the wall of the left ventricle, usually a consequence of myocardial infarction.
cirsoid aneurysm
dilatation and tortuous lengthening of part of an artery.
compound aneurysm
one in which some of the layers of the wall of the vessel are ruptured and some merely dilated. Called also mixed aneurysm.
congenital aneurysm
observed sporadically in the aorta and pulmonary artery.
dissecting aneurysm
one resulting from hemorrhage that causes lengthwise splitting of the arterial wall, producing a tear in the inner wall (intima) and establishing communication with the lumen of the vessel; it usually affects the thoracic aorta. Seen most commonly in horses and caused by larvae of Strongylus vulgaris. See strongylosis. A specific disease of turkeys.
fusiform aneurysm
a spindle-shaped aneurysm.
infected aneurysm
one produced by growth of microorganisms (bacteria or fungi) in the vessel wall, or infection arising within a pre-existing arteriosclerotic aneurysm.
inherited aortic aneurysm
causes a high mortality rate in the affected cattle breed. The defect is in the abdominal aorta.
lung aneurysm
may result from the lodgement of pulmonary emboli; rupture and pulmonary hemorrhage are potential sequelae.
mixed aneurysm
compound aneurysm.
mycotic aneurysm
an infected aneurysm caused by fungi.
pseudoaneurysm
false aneurysm.
racemose aneurysm
cirsoid aneurysm.
sacculated aneurysm
a saclike aneurysm.
varicose aneurysm
one formed by rupture of an aneurysm into a vein. See also aneurysmal varix.
venous aneurysm
see venous dilatation.
verminous aneurysm
References in periodicals archive ?
Although the risk of the rupture of the aneurysm is eliminated, there is a predisposition for the recurrence of the mycotic aneurysm and the development of an AEF in this hostile environment if the infection source is not eradicated, as was the case in our patient.
Several days later, a cerebral angiogram shows multiple mycotic aneurysms (MAs), which the neurosurgeon suspects derived from his endocarditis.
Mycotic aneurysms have widely varying clinical presentations depending on their location, the duration of infection, and patient comorbidities.
Mycotic aneurysm due to Burkholderia pseudomallei infection: case reports and literature review.
Elective Embolization of Ruptured Mycotic Aneurysm of The Duodeno-Pancreatic Arcade Disclosing Infectious Endocarditis.
Mycotic aneurysm in the aortic arch of a horse associated with invasive aspergillosis.
These findings are highly suggestive of a mycotic aneurysm of the abdominal aorta.
Intracerebral hemorrhage associated with mycotic aneurysm in a patient with mitral valve endocarditis.
A computed tomographic scan revealed a suprarenal mycotic aneurysm of the aorta.
INTRODUCTION: The term Mycotic aneurysm is a misnomer that has nevertheless been generally adopted to describe aneurysms that occur secondary to the infectious destruction of an arterial wall.
Described complications of SVGA in the literature include ischemia from stenosis or localized compression of a coronary artery aneurysm rupture with subsequent hemothorax or cardiac tamponade, fistula formation to adjacent cardiac tissues such as the right ventricle, mycotic aneurysm, and superior vena cava syndrome.