Anastomosis device

An anastomosis device configured to reduce leakage, comprising:

• a set of two rings for positioning over adjacent first and second tissue walls, each ring comprising at least:
• a first chamber configured to apply a first pressure onto a respective tissue wall out of the first and second tissue walls, the pressure sufficient to form a passage between the first and second tissue walls;
• and
• a second chamber configured to apply a second pressure onto the respective tissue wall out of the first and second tissue walls, the pressure applied radially outwardly relative to the first pressure, the second pressure sufficient to reduce leakage in a vicinity of the passage.

An anastomosis device configured to reduce leakage, comprising:

• a first set of structures shaped and sized to be positioned at a first tissue wall;
• a second set of structures shaped and sized to be positioned at a second tissue wall, the second tissue wall being adjacent the first tissue wall;
• and
• an element configured to draw the sets towards each other;
• wherein each set of structures comprises an inner substantially closed shape, an outer substantially closed shape surrounding the inner shape, and a coupling element between the inner substantially closed shape and the outer substantially closed shapes, the coupling element configured to control a ratio between a first pressure applied by the inner substantially closed shape onto the tissue, and a second pressure applied by the outer substantially closed shape onto the tissue.