Circulatory anastomosis

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:

• Circle of Willis (in the brain)
• Coronary: anterior interventricular artery and posterior interventricular artery of the heart
• Scapular anastomosis (for the subclavian vessels)
• Joint anastomoses: Almost all joints receive anastomotic blood supply from more than one source.
  • Shoulder (and circumflex humeral)
  • Elbow (see blood supply of elbow)
  • Hip (and circumflex iliac; see also cruciate anastomosis)
  • Knee (and genicular arteries; see also patellar network)
  • Ankle
• Abdominal anastomoses
  • Marginal artery of the colon
• Pelvic anastomoses
• Hand - palmar arches: superficial palmar arch and deep palmar arch
• Foot - plantar arch

Coronary

Surgical intervention

Coronary anastomoses are a clinically vital subject: the coronary anastomosis is the blood supply to the heart. The coronary arteries are vulnerable to arteriosclerosis and other effects. Inadequate supply to the heart will lead to chest pains (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.

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.