A blood pump comprises a pump casing having a blood flow inlet and a blood flow outlet, and an impeller arranged in said pump casing so as to be rotatable about an axis of rotation. The impeller has blades sized and shaped for conveying blood from the blood flow inlet to the blood flow outlet. The blood pump also has an outflow cannula having an upstream end portion, a downstream end portion and an intermediate portion extending between the upstream end portion and the downstream end portion. The upstream end portion of the outflow cannula is connected to the pump casing such that blood is conveyed from the blood flow outlet of the pump casing into and through the intermediate portion of the outflow cannula towards the downstream end portion of the outflow cannula, wherein the downstream end portion has a blood flow outlet through which blood can exit the outflow cannula. At least a portion of the intermediate portion of the outflow cannula has an outer diameter that is larger than an outer diameter of the pump casing.

A blood pump comprises a pump casing having a blood flow inlet and a blood flow outlet, and an impeller arranged in said pump casing so as to be rotatable about an axis of rotation. The impeller has blades sized and shaped for conveying blood from the blood flow inlet to the blood flow outlet. The blood pump also has an outflow cannula having an upstream end portion, a downstream end portion and an intermediate portion extending between the upstream end portion and the downstream end portion. The upstream end portion of the outflow cannula is connected to the pump casing such that blood is conveyed from the blood flow outlet of the pump casing into and through the intermediate portion of the outflow cannula towards the downstream end portion of the outflow cannula, wherein the downstream end portion has a blood flow outlet through which blood can exit the outflow cannula. At least a portion of the intermediate portion of the outflow cannula has an outer diameter that is larger than an outer diameter of the pump casing.

A partially deformable impeller has at least two blades, wherein a periphery of each blade is deformable, the periphery being an outermost 5 to 20 percent of a width of the blade. In some embodiments, a catheter blood pump incorporates the partially deformable impeller.

A partially deformable impeller has at least two blades, wherein a periphery of each blade is deformable, the periphery being an outermost 5 to 20 percent of a width of the blade. In some embodiments, a catheter blood pump incorporates the partially deformable impeller.