Support structures for intravascular blood pumps

Abstract

An improved system for supporting (e.g., localization and/or positioning of) intravascular devices discussed herein provides for example a multi-element arrangement. A set of struts optionally projects from the intravascular device and contacts the vessel walls. The localization and positioning of the pump may be provided by the struts and/or by use of a tether opposing a propulsive force to ensure localization.

1 . (canceled) 
     
     
         2 . A method of operating a blood flow assist system, the method comprising:
 providing a pump at a treatment location within a blood vessel of a patient, the pump including a pump housing disposed in a sheath, an impeller disposed in the pump housing, and a plurality of elongate struts extending from the pump housing in a collapsed configuration, each elongate strut of the plurality of struts including a convex contact pad at a distal end thereof;   removing the pump from the sheath, the plurality of elongate struts radially self-expanding to an expanded configuration in which at least one convex contact pad at least intermittently makes contact with a vessel wall of the blood vessel to maintain spacing of the pump from the vessel wall; and   rotating the impeller to pump blood.   
     
     
         3 . The method of  claim 2 , further comprising conveying electrical current to a motor by way of a tether comprising a conductor, the motor operatively coupled with the impeller and the tether coupled to the pump, wherein rotating the impeller generates a thrust force, the tether opposing the thrush force. 
     
     
         4 . The method of  claim 2 , further comprising percutaneously delivering the sheath to the treatment location, and, subsequently, delivering the pump to the treatment location. 
     
     
         5 . The method of  claim 2 , further comprising causing a portion of the contact pad to depress into the vessel wall. 
     
     
         6 . The method of  claim 2 , further comprising removing the pump from the patient. 
     
     
         7 . The method of  claim 2 , wherein removing the pump from the sheath comprises providing relative motion between the sheath and the pump. 
     
     
         8 . The method of  claim 2 , further comprising collapsing the plurality of elongate struts. 
     
     
         9 . The method of  claim 8 , wherein each strut of the plurality of elongate struts comprises a knee, wherein collapsing the plurality of elongate struts comprises engaging each knee with a distal end of the sheath. 
     
     
         10 . The method of  claim 2 , wherein each elongate strut of the plurality of elongate struts includes an inflection zone disposed between a distal end and a proximal end of the elongate strut. 
     
     
         11 . The method of  claim 10 , wherein the inflection zone of each strut spaces the distal end of the strut from an inner wall of the sheath in the collapsed configuration. 
     
     
         12 . A method of operating a blood flow assist system, the method comprising:
 providing a pump at a treatment location within a blood vessel of a patient, the pump including a pump housing disposed in a sheath, an impeller disposed in the pump housing, and a plurality of elongate struts extending distally from the pump housing in a collapsed configuration;   removing the pump from the sheath, the plurality of elongate struts radially self-expanding to an expanded configuration in which at least one contact pad at an end of at least one strut of the plurality of elongate struts at least intermittently makes contact with a vessel wall of the blood vessel to maintain spacing of the pump from the vessel wall, the at least one contact pad applying sufficient force to the vessel wall of the blood vessel to depress a portion of the contact pad into the vessel wall such that a surrounding portion of the vessel wall is radially inward from the contact pad; and   rotating the impeller to pump blood.   
     
     
         13 . The method of  claim 12 , further comprising percutaneously delivering the sheath to the treatment location, and, subsequently, delivering the pump to the treatment location. 
     
     
         14 . The method of  claim 12 , further comprising removing the pump from the patient. 
     
     
         15 . The method of  claim 12 , further comprising conveying electrical current to a motor by way of a tether comprising a conductor, the motor operatively coupled with the impeller and the tether coupled to the pump. 
     
     
         16 . The method of  claim 12 , wherein each elongate strut of the plurality of elongate struts includes a convex contact pad at a distal end thereof. 
     
     
         17 . The method of  claim 12 , wherein each elongate strut of the plurality of elongate struts includes an inflection zone disposed between a distal end and a proximal end of the elongate strut, wherein the inflection zone of each strut spaces the distal end of the strut from an inner wall of the sheath in the collapsed configuration.