Microangiopathy (also known as microvascular disease, small vessel disease (SVD) or microvascular dysfunction) is a disease of the

microvessel The microcirculation is the circulation of the blood in the smallest blood vessels, the microvessels of the microvasculature present within organ tissues. The microvessels include terminal arterioles, metarterioles, capillaries, and venule ...

s, small

blood vessel The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide awa ...

s in the

microcirculation The microcirculation is the circulation of the blood in the smallest blood vessels, the microvessels of the microvasculature present within organ tissues. The microvessels include terminal arterioles, metarterioles, capillaries, and venules. ...

. It can be contrasted to

coronary heart disease Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic pl ...

, an

angiopathy Angiopathy is the generic term for a disease of the blood vessels (arteries, veins, and capillaries). The best known and most prevalent angiopathy is diabetic angiopathy, a common complication of chronic diabetes. Classification By caliber Ther ...

that affects the larger vessels.

Type

Cerebral small vessel disease refers to a group of diseases that affect the small

arteries An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pu ...

arteriole An arteriole is a small-diameter blood vessel in the microcirculation that extends and branches out from an artery and leads to capillaries. Arterioles have muscular walls (usually only one to two layers of smooth muscle cells) and are the primar ...

venule A venule is a very small blood vessel in the microcirculation that allows blood to return from the capillary beds to drain into the larger blood vessels, the veins. Venules range from 7μm to 1mm in diameter. Veins contain approximately 70% of ...

s, and

capillaries A capillary is a small blood vessel from 5 to 10 micrometres (μm) in diameter. Capillaries are composed of only the tunica intima, consisting of a thin wall of simple squamous endothelial cells. They are the smallest blood vessels in the body: ...

of the

brain A brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as Visual perception, vision. I ...

. Age-related and

hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high b ...

-related small vessel diseases and

cerebral amyloid angiopathy Cerebral amyloid angiopathy (CAA) is a form of angiopathy in which amyloid beta peptide deposits in the walls of small to medium blood vessels of the central nervous system and meninges. The term ''congophilic'' is sometimes used because the pr ...

are the most common forms. Coronary small vessel disease is a type of coronary heart disease that affects the

arterioles An arteriole is a small-diameter blood vessel in the microcirculation that extends and branches out from an artery and leads to capillaries. Arterioles have muscular walls (usually only one to two layers of smooth muscle cells) and are the pri ...

and

of the

heart The heart is a muscular Organ (biology), organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as ca ...

. Coronary small vessel disease is also known as microvascular angina, microvascular dysfunction, non-obstructive coronary disease, or previously ''cardiac syndrome X''.

Pathophysiology

One cause of microangiopathy is long-term

diabetes mellitus Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...

. In this case, high

blood glucose Glycaemia, also known as blood sugar level, blood sugar concentration, or blood glucose level is the measure of glucose concentrated in the blood of humans or other animals. Approximately 4 grams of glucose, a simple sugar, is present in the b ...

levels cause the

endothelial cell The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vesse ...

s lining the blood vessels to take in more glucose than normal (these cells do not depend on

insulin Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the ''INS'' gene. It is considered to be the main anabolic hormone of the body. It regulates the metabolism ...

). They then form more

glycoprotein Glycoproteins are proteins which contain oligosaccharide chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glyco ...

s on their surface than normal, and also cause the

basement membrane The basement membrane is a thin, pliable sheet-like type of extracellular matrix that provides cell and tissue support and acts as a platform for complex signalling. The basement membrane sits between epithelial tissues including mesothelium an ...

in the vessel wall to grow abnormally thicker and weaker. Therefore, they bleed, leak protein, and slow the flow of

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...

through the body. As a result, some organs and tissues do not get enough blood (carrying oxygen and nutrients) and are damaged, for example, the retina (

diabetic retinopathy Diabetic retinopathy (also known as diabetic eye disease), is a medical condition in which damage occurs to the retina due to diabetes mellitus. It is a leading cause of blindness in developed countries. Diabetic retinopathy affects up to 80 perc ...

) or kidney (

diabetic nephropathy Diabetic nephropathy, also known as diabetic kidney disease, is the chronic loss of kidney function occurring in those with diabetes mellitus. Diabetic nephropathy is the leading causes of chronic kidney disease (CKD) and end-stage renal disease ...

). Nerves and neurons, if not sufficiently supplied with blood, are also damaged, which leads to loss of function (

diabetic neuropathy Diabetic neuropathy is various types of nerve damage associated with diabetes mellitus. Symptoms depend on the site of nerve damage and can include motor changes such as weakness; sensory symptoms such as numbness, tingling, or pain; or autonomic c ...

, especially

peripheral neuropathy Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or or ...

). Massive microangiopathy may cause

microangiopathic hemolytic anemia Microangiopathic hemolytic anemia (MAHA) is a microangiopathic subgroup of hemolytic anemia (loss of red blood cells through destruction) caused by factors in the small blood vessels. It is identified by the finding of anemia and schistocytes ...

(MAHA).

Diagnosis

Treatment

See therapy of

arteriosclerosis Arteriosclerosis is the thickening, hardening, and loss of elasticity of the walls of arteries. This process gradually restricts the blood flow to one's organs and tissues and can lead to severe health risks brought on by atherosclerosis, which ...

. Laser therapy of diabetic retinopathy. A number of medicines, such as calcium dobesilate, are being marketed for the specific treatment of microangiopathy. The efficacy of calcium dobesilate has been described e.g. in patients with diabetic retinopathy or diabetic nephropathy.

References

External links

{{Vascular diseases Histopathology