Blood pump with expandable cannula

A pump, comprising:

• an elongated cannula having a proximal portion and a distal portion, the distal portion comprising an expandable portion;
• an impeller disposed in the expandable portion;
• a sheath having a generally non-expanding distal portion;
• and
• one or more guidance aids configured to facilitate retraction of the expandable portion into the distal portion of the sheath when relative motion is provided between the distal portion of the sheath and the expandable portion.

A method of pumping blood in a patient, comprising:

• inserting a blood pump into the patient, the blood pump comprising an elongated cannula, an impeller positioned in the elongated cannula, and an expandable vane assembly positioned in the elongated cannula near the impeller, the expandable vane assembly having a deployed configuration and a stored configuration, the vane assembly comprising a vane;
• positioning the blood pump in the patient so that the impeller is at a desired location;
• expanding the expandable vane assembly from the stored configuration to the deployed configuration within the elongated cannula;
• and
• rotating the impeller about an axis to pump blood through the elongated cannula.