Endoluminal prosthesis deployment devices and methods

Abstract

Catheter systems and methods for deployment of an endoluminal prosthesis in a body lumen of a patient while maintaining control of a position of the endoluminal prosthesis during the deployment process. Some of the systems and methods are configured to minimize frictional forces of components of the catheter systems during deployment procedures.

What is claimed is: 
     
         1 . A catheter system for deploying an endoluminal prosthesis in a body lumen of a patient, comprising:
 a flexible elongate chassis having a proximal end, a distal end, a distal section and an overall column strength sufficient for advancing of the chassis through the body lumen of the patient;   the endoluminal prosthesis, the endoluminal prosthesis being a self-expanding tubular endoluminal prosthesis disposed in a constrained state over the distal section of the chassis; and   a thin, flexible, resilient extension comprising:
 a proximal end secured in fixed relation to the chassis, 
 a distal end disposed radially outward from an outside surface of the chassis and distal of the proximal end of the extension; 
   wherein the extension extends through a wall of a distal end of the endoluminal prosthesis with the extension in a radially constrained state such that the extension at least partially captures a distal segment of the endoluminal prosthesis and restricts proximal displacement of the endoluminal prosthesis relative to the chassis, wherein the extension comprises an s-shape in an unconstrained relaxed state.   
     
     
         2 . The catheter system of  claim 1 , wherein a proximal most deflection of the s-shape of the extension and a distal most deflection of the s-shape of the extension extend in different directions. 
     
     
         3 . The catheter system of  claim 2 , wherein
 the catheter system further comprises a tubular outer sheath disposed over the endoluminal prosthesis and chassis; and   the tubular outer sheath comprises an inner surface that constrains the endoluminal prosthesis in the constrained state.   
     
     
         4 . The catheter system of  claim 4 , wherein an outward facing curvature of the proximal most deflection corresponds to a rounded profile shaped for passage within the constraining tubular structure. 
     
     
         5 . The catheter system of  claim 2 , wherein the proximal most deflection provides a gap between an outer surface of the chassis and the extension. 
     
     
         6 . A catheter system for deploying an endoluminal prosthesis in a body lumen of a patient, comprising:
 a flexible elongate chassis having a proximal end, a distal end, and a column strength configured for advancement of the chassis through a body lumen of a patient;   a self-expanding tubular endoluminal prosthesis disposed in a constrained state at the distal end of the chassis; and   a tubular everting sheath which comprises:
 an inner section which comprises a first diameter, a fixed end which is secured in fixed relation to the chassis and an endoluminal prosthesis section that is disposed over and radially constrains the endoluminal prosthesis in the constrained state, and 
 an outer section that is everted back over the endoluminal prosthesis section of the inner section, the outer section comprising a retraction end and a second diameter which is larger than the first diameter of the inner section such that the outer section is readily slideable over the inner section during retraction of the retraction end and eversion of the everting sheath. 
   
     
     
         7 . The catheter system of  claim 6 , wherein the second diameter of the outer section is greater than the first diameter of the inner section by an amount of at least a wall thickness of the outer section of the tubular everting sheath. 
     
     
         8 . The catheter system of  claim 6 , further comprising:
 an integral funnel section disposed at the retraction end of the outer section of the everting sheath, wherein the funnel section has a major diameter at an opening thereof that is greater than an outer diameter of the endoluminal prosthesis in a relaxed expanded state; and   a retraction tether secured to and extends from the integral funnel.   
     
     
         9 . The catheter system of  claim 6 , further comprising a nosecone, wherein at least one of:
 the nosecone is secured to the chassis in an axial position which is distal of the endoluminal prosthesis; or   the nosecone is secured to the distal end of the chassis, the nosecone comprising a shoulder portion which is disposed within a distal end of the tubular everting sheath.   
     
     
         10 . The catheter system of  claim 6 , further comprising a proximal adapter secured to a proximal end of the chassis. 
     
     
         11 . The catheter system of  claim 6 , wherein the chassis comprises a guidewire lumen extending from the proximal end of the chassis to the distal end of the chassis. 
     
     
         12 . The catheter system of  claim 6 , wherein
 the tubular endoluminal prosthesis comprises a tubular stent graft comprising at least one layer of compliant material secured to a self-expanding stent; and   the stent graft comprises a fully stented stent graft.   
     
     
         13 . A catheter system for deploying an endoluminal prosthesis in a body lumen of a patient, comprising:
 a flexible elongate chassis having a proximal end, a distal end, and a column strength configured for advancement of the chassis through a body lumen of a patient;   a self-expanding tubular endoluminal prosthesis disposed in a constrained state at the distal end of the chassis; and   a tubular everting sheath which comprises
 an inner section which comprises a fixed end which is secured in fixed relation to the chassis and an endoluminal prosthesis section that is disposed over and radially constrains the endoluminal prosthesis in the constrained state, 
 an outer section that is everted back over the endoluminal prosthesis section of the inner section, the outer section comprising a retraction end, and 
 a PTFE material having a closed cell microstructure with no distinct fibrils interconnecting adjacent nodes such that the outer section is readily slideable over the inner section. 
   
     
     
         14 . The catheter system of  claim 13 , wherein
 the everting sheath comprises a layered tubular structure comprising a plurality of layers of compliant PTFE material which are secured together;   the PTFE material structure layup is anisotropically oriented for strength along at least one of a longitudinal direction of the everting sheath or a circumferential direction of the everting sheath.   
     
     
         15 . The catheter system of  claim 14 , further comprising a thin, elongate, high tensile retraction tether disposed between adjacent layers of the layered tubular structure of the everting sheath and extending longitudinally along the endoluminal prosthesis section and outer section of the everting sheath. 
     
     
         16 . The catheter system of  claim 15 , further comprising a plurality of thin, elongate, high tensile retraction tethers disposed between two adjacent layers of the layered tubular structure of the everting sheath, wherein the plurality of thin, elongate, high tensile retraction tethers are helically wound about a tubular structure of the everting sheath. 
     
     
         17 . A method of loading an endoluminal prosthesis into a sheath which is configured to constrain the endoluminal prosthesis, comprising:
 passing a plurality of thin high tensile tethers loops through an end of the endoluminal prosthesis;   passing the plurality of tether loops through an inner lumen of the sheath; restraining an end of the sheath and pulling on both ends of each of the tether loops simultaneously such that the tether loops are pulled through the inner lumen of the sheath so as to apply tension to the endoluminal prosthesis such that the endoluminal prosthesis is radially compressed and constrained as it is pulled into the inner lumen of the sheath to an endoluminal prosthesis section within the inner lumen of the sheath; and   thereafter pulling on only one side of each of the tether loops and releasing an opposite end of each tether loop until each of the tether loops is pulled out of the endoluminal prosthesis and the inner lumen of the sheath.   
     
     
         18 . The method of  claim 17 , wherein the sheath configured to constrain the endoluminal prosthesis comprises an everting sheath of a catheter system. 
     
     
         19 . The method of  claim 18 , wherein the sheath comprises an everting sheath and wherein pulling the tethers comprises pulling them through the everting sheath until the endoluminal prosthesis is disposed within and constrained by an endoluminal prosthesis section of an inner section of the everting sheath. 
     
     
         20 . The method of  claim 17 , wherein the sheath configured to constrain the endoluminal prosthesis comprises a proximally retractable outer sheath of a catheter system.