A perfusion lumen (17) is connected to at least one perfusion blood vessel (15) among a plurality of blood vessels that extends from a branch of a plurality of blood vessels protruding from a liver, the branch existing on a distal side viewed from the liver, to a further distal side viewed from the liver. The perfusion lumen (17) is supplied with perfusate to perfuse the liver and maintain the condition of the liver. Among blood vessels that are not connected to the perfusion lumen, at least one conserved blood vessel (11) is obstructed and conserved for anastomosis to a blood vessel of the living body. Accordingly, the perfusion state of the liver is maintained even during anastomosis to the blood vessels of the living body. This enables anastomosis to the blood vessels of the living body while maintaining the perfusion state of the liver.
