A blood pump for supporting a patient's heart includes a flow cannula having a distal portion including a distal end and a proximal portion including a proximal end opposite the distal end, the distal end of the flow cannula configured to be connected to the patient's heart or a blood vessel to establish fluid communication between the blood pump and the patient's heart and blood vessel, respectively. The flow cannula further includes an intermediate portion attached to the distal portion and the proximal portion, wherein the intermediate portion allows twisting thereof with a lower force than the distal portion and the proximal portion. The intermediate portion can be fully occluded by twisting it. At least a portion of the intermediate portion either alone or in combination with the distal portion is adapted to be permanently attached to the patient's heart or a blood vessel.