Circulatory anastomosis

Source: Wikipedia, the free encyclopedia.

A circulatory anastomosis is a connection (an

arteries (arterio-arterial anastomosis), between veins (veno-venous anastomosis) or between an artery and a vein (arterio-venous anastomosis). Anastomoses between arteries and between veins result in a multitude of arteries and veins, respectively, serving the same volume of tissue. Such anastomoses occur normally in the body in the circulatory system, serving as back-up routes in a collateral circulation that allow blood to flow if one link is blocked or otherwise compromised, but may also occur pathologically.[1]

Physiologic

Arterio-arterial anastomoses include actual (e.g., palmar and plantar arches) and potential varieties (e.g., coronary arteries and cortical branch of cerebral arteries).

There are many examples of normal arterio-arterial anastomoses in the body. Clinically important examples include:

Coronary

Surgical intervention

Further information: Surgical anastomosis

Coronary anastomoses are a clinically vital subject: the coronary anastomosis is the blood supply to the heart. The coronary arteries are vulnerable to

angina) or a heart attack (myocardial infarction). These can be ameliorated by surgical intervention to create a bypass using the anastomosis technique. Creation of an end-to-end anastomosis is a basic microsurgical skill that is taught to surgical residents and fellows. [2]

Naturally occurring

Coronary anastomoses are anatomically present though functionally obsolete. There was some suggestion that they may be helpful if a problem develops slowly over time (this will need to be verified) but in the case of the pathogenesis of CHD they do not provide a sufficient blood flow to prevent infarction.

There are anastomoses between the Circumflex and right coronary arteries and between the anterior and posterior inter-ventricular arteries. In the normal heart these anastomoses are non-functional.

Arterio-venous

Superficial arterio-venous anastomoses open when the body reaches a high temperature, and enable the body to cool itself. As warm arterial blood passes close to the surface it will decrease in temperature. This occurs together with

sweating.[citation needed
]

Pathologic

hemorrhoids, esophageal varices, or caput medusae
.

Circulatory anastomoses between monochorionic twins may result in twin-to-twin transfusion syndrome.[3]

References

  1. ^ Johnson, DR. "Introductory Anatomy: Circulatory System and Blood". Archived from the original on November 8, 2010. Retrieved February 21, 2011.
  2. ^ Akelina Y. Microsurgical technique for 1mm vessel end to end anastomosis. J Med Ins. 2014;2014(2). doi:https://doi.org/10.24296/jomi/2
  3. ISBN 0-8247-2844-0
    .
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