ANASTOMOSIS

n. network of connecting channels (between veins of leaves, rivers, etc.); surgical connection of one organ to another (as in separate parts of the intestine)

Anastomosis (plural anastomoses) refers to a form of network in which streams both branch out and reconnect. The term is used in medicine, biology, and geology.
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Anastomosis /anas·to·mo·sis/ pl. anastomo´ses [Gr.] 1. communication between vessels by collateral channels. 2. [more]Anastomosis - Community and Resources

Noun
1. a natural or surgical joining of parts or branches of tubular structures so as to make or become continuous
(synonym) inosculation
(hypernym) junction, conjunction, conjugation, colligation

n. anastomosis