2. The connection or communication between two tubular organs of normally separate parts or spaces so they intercommunicate.
3. The connection or place of connection of two or more parts of a natural branching system; for example, of blood vessels, leaf veins, stems of woody plants, or rivers.
4. The surgical union of two hollow organs: such as, blood vessels or parts of the intestine, to ensure continuity of the passageways.
An anastomosis may be naturally occurring or artificially constructed and be created during the process of embryonic development or by surgery, trauma, or pathological means.
For example, an anastomosis may connect two blood vessels (as in a naturally occurring arteriovenous anastomosis, a connection between an artery and a vein) or it may connect the healthy sections of the colon or rectum after a cancerous or otherwise diseased portion has been surgically removed.
A gastrojejunal anastomosis connects the stomach directly with the jejunum or part of the small intestine.
The term anastomosis comes from Greek. It originally referred to an opening or junction through a mouth as of one body of water with another.
Anastomosis has been in medical usage since the Greek physician Galen (129-200 A.D.) used it to describe the interconnections between blood vessels.