Sheath assembly for catheter pump

A catheter pump assembly, comprising:

• a pump including an impeller assembly;
• and
• a catheter body disposed proximal to and supporting the pump,
• wherein the catheter body includes relatively hard sections each having a hardness greater than 40 D adjacent to a relatively softer middle section having a hardness less than 40 D such that the middle section is configured to contact a wall of an aorta of a patient.

A catheter pump assembly, comprising:

• a pump including an impeller assembly;
• a catheter body having a coupling section, a vessel wall contact surface distal to the coupling section and a bending section located between the coupling section and the vessel wall contact surface, the coupling section disposed proximally of and configured to couple with the impeller assembly and having a first stiffness, the vessel wall contact surface having a second stiffness and configured to bear against an outer radius of an aortic arch;
• and
• the bending section having a third stiffness lower than the first stiffness and the second stiffness such that loads applied distal the vessel wall contact surface result in flexing at the bending section.

A method, comprising:

• advancing a distal portion of a catheter assembly including an impeller assembly and a catheter body to a treatment location of a patient;
• wherein the catheter body has a coupling section, a vessel wall contact surface distal to the coupling section and a bending section located between the coupling section and the vessel wall contact surface, the coupling section disposed proximally of and configured to couple with the impeller assembly and having a first stiffness, the vessel wall contact surface having a second stiffness, and the bending section having a third stiffness lower than the first stiffness and the second stiffness such that loads applied distal the vessel wall contact surface result in flexing at the bending section
• contacting the vessel wall contact surface of the catheter body with a contact zone of an inner wall of an aorta of the patient to secure at least the distal portion of the catheter assembly against the aorta of the patient, the inner wall being located adjacent to the junction of the ascending aorta and the aortic arch;
• activating the impeller assembly to pump blood across the aortic valve;
• and
• maintaining the contact between the vessel wall contact surface of the catheter body and the contact zone while the impeller assembly is activated.