Watershed area (medical)
Encyclopedia
Watershed area is the medical term referring to regions of the body that receive dual blood supply from the most distal branches of two large arteries, such as the splenic flexure
of the large intestine
.
During times of blockage of one of the arteries that supply the watershed area, such as in atherosclerosis
, these regions are spared from ischemia
by virtue of their dual supply. However, during times of systemic hypoperfusion, such as in disseminated intravascular coagulation
or Heart failure, these regions are particularly vulnerable to ischemia by virtue of the fact that they are supplied by the most distal branches of their arteries, and thus the least likely to receive sufficient blood.
When watershed stroke
occurs in the brain, it produces unique focal neurologic symptoms that aid clinicians in diagnosis and localization.
Hypoperfusion in watershed areas can lead to Mural and Mucosal infarction in the case of Ischemic Bowel Disease.
Splenic flexure
The splenic flexure is a sharp bend between the transverse and the descending colon in the left upper quadrant of humans. The left colic flexure is near the spleen, and hence called the splenic flexure. There are two colic flexures in the transverse colon — the other being the hepatic...
of the large intestine
Large intestine
The large intestine is the third-to-last part of the digestive system — — in vertebrate animals. Its function is to absorb water from the remaining indigestible food matter, and then to pass useless waste material from the body...
.
During times of blockage of one of the arteries that supply the watershed area, such as in atherosclerosis
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
, these regions are spared from ischemia
Ischemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...
by virtue of their dual supply. However, during times of systemic hypoperfusion, such as in disseminated intravascular coagulation
Disseminated intravascular coagulation
Disseminated intravascular coagulation , also known as disseminated intravascular coagulopathy or consumptive coagulopathy, is a pathological activation of coagulation mechanisms that happens in response to a variety of diseases. DIC leads to the formation of small blood clots inside the blood...
or Heart failure, these regions are particularly vulnerable to ischemia by virtue of the fact that they are supplied by the most distal branches of their arteries, and thus the least likely to receive sufficient blood.
When watershed stroke
Watershed stroke
A watershed stroke is defined as an ischemia, or blood flow blockage, that is localized to the border zones between the territories of two major arteries in the brain...
occurs in the brain, it produces unique focal neurologic symptoms that aid clinicians in diagnosis and localization.
Hypoperfusion in watershed areas can lead to Mural and Mucosal infarction in the case of Ischemic Bowel Disease.