Implantable mechanical circulatory support devices

A method of implanting a mechanical circulatory support device in a patient having a body having a thorax and a circulatory system including a heart having a ventricle, comprising:

• forming a pocket within the body of the patient outside of the thoracic cavity;
• implanting a housing within the pocket, the housing having:
• an inner casing defining a fluid flow path and a longitudinal axis along the fluid flow path;
• a rotor mounted within the fluid flow path;
• the housing having a cross-sectional shape in a plane transverse to the longitudinal axis, the housing defines a first surface disposed about the longitudinal axis and a second planar surface transverse the longitudinal axis;
• and
• fluidly coupling the fluid flow path to the circulatory system of the patient.