Vascular occlusion is a blockage of a blood vessel, usually with a
clot. It differs from
thrombosis
Thrombosis (from Ancient Greek "clotting") is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (th ...
in that it can be used to describe any form of blockage, not just one formed by a clot. When it occurs in a major
vein
Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated ...
, it can, in some cases, cause
deep vein thrombosis. The condition is also relatively common in the
retina
The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which the ...
, and can cause partial or total loss of vision. An occlusion can often be diagnosed using
Doppler sonography
Doppler ultrasonography is medical ultrasonography that employs the Doppler effect to perform imaging of the movement of tissues and body fluids (usually blood), and their relative velocity to the probe. By calculating the frequency shift of a ...
(a form of
ultrasound
Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies ...
).
Some medical procedures, such as
embolisation, involve occluding a blood vessel to treat a particular condition. This can be to reduce pressure on
aneurysm
An aneurysm is an outward 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 be a nidus ( ...
s (weakened blood vessels) or to restrict a
haemorrhage. It can also be used to reduce blood supply to tumours or growths in the body, and therefore restrict their development. Occlusion can be carried out using a
ligature; by implanting small coils which stimulate the formation of clots; or, particularly in the case of
cerebral aneurysms, by
clipping.
See also
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Central retinal artery occlusion
Central retinal artery occlusion (CRAO) is a disease of the eye where the flow of blood through the central retinal artery is blocked (occluded). There are several different causes of this occlusion; the most common is carotid artery atherosclero ...
*
Central retinal vein occlusion
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Branch retinal artery occlusion
Branch retinal artery occlusion (BRAO) is a rare retinal vascular disorder in which one of the branches of the central retinal artery is obstructed.
Presentation
Abrupt painless loss of vision in the visual field corresponding to territory of the ...
*
Branch retinal vein occlusion
Branch retinal vein occlusion is a common retinal vascular disease of the elderly. It is caused by the occlusion of one of the branches of central retinal vein.
Signs and symptoms
Patients with branch retinal vein occlusion usually have a sudden ...
References
Medical terminology
Hematology
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