Endovascular delivery system with flexible and torqueable hypotube

Abstract

A medical device includes an elongate metallic hypotube having an open proximal end and an opposed open distal end defining a tubular wall having an open internal diameter and an exterior diameter. The tubular wall has a first flexible portion disposed near the proximal open end and a second portion disposed near the distal open end. The first flexible portion of the hypotube includes a plurality of slots extending through the tubular wall and having a circumferential arc from about 150° to about 300°; and where adjacent slots are axially offset from one and the other from about 30° to about 60°. The medical device may be used as part of an endovascular delivery system.

1 .- 27 . (canceled) 
     
     
         28 . An endovascular delivery system, comprising:
 an elongate outer tubular sheath having an open lumen and opposed proximal and distal ends with a medial portion therein between;   an elongate inner metallic hypotube having a tubular wall with an open lumen and opposed proximal and distal ends with a medial portion therein between, the hypotube having a longitudinal length greater than a longitudinal length of the outer tubular sheath, the hypotube being slidably disposed within the open lumen of the outer tubular sheath;   the distal end of the outer tubular sheath being slidably disposed past and beyond the distal end of the hypotube to define an endovascular prosthesis delivery state and slidably retractable to the medial portion of the hypotube to define an endovascular prosthesis unsheathed state;   wherein the hypotube further comprises:
 a first flexible portion disposed from about the distal end of the hypotube to about the medial portion of the hypotube; 
 a second portion disposed from about the medial portion of the hypotube to about the proximal end of the hypotube; 
 the first flexible portion of the hypotube comprising a plurality of slots extending through the tubular wall of the hypotube, said slots having a circumferential arc about the tubular wall from about 150° to about 300°; 
 wherein adjacent slots are axially offset from one and the other from about 30° to about 60°; 
 wherein at least one end of the hypotube includes a hole for securement to the delivery system proximal to that end; and 
 wherein the hypotube has a polymeric covering of a polymer coating or a polymer extrusion. 
   
     
     
         29 . The endovascular delivery system of  claim 28 , wherein the polymeric coating is selected from the group consisting of polytetrafluoroethylene (PTFE) and poly(p-xylylene) polymers (Parylene). 
     
     
         30 . The endovascular delivery system of  claim 28 , wherein a thickness of the polymer coating is less than about 0.0005 inches. 
     
     
         31 . The endovascular delivery system of  claim 28 , wherein the polymer extrusion includes polymers selected from the group consisting of polytetrafluoroethylene (PTFE), ethylenetetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), perfluoroalkoxy (PFA), polyethylene terephthalate (PET) and polyethylene co-extrusions. 
     
     
         32 . The endovascular delivery system of  claim 28 , wherein the polymer extrusion includes heat-shrinkable polymers. 
     
     
         33 . The endovascular delivery system of  claim 28 , wherein a thickness of the polymer extrusion is from about 0.0005 inches to about 0.002 inches. 
     
     
         34 . The endovascular delivery system of  claim 28 , wherein the polymer coating or the polymer extrusion covers the slots. 
     
     
         35 . The endovascular delivery system of  claim 28 , wherein the polymer coating or the polymer extrusion does not cover the slots. 
     
     
         36 . The endovascular delivery system of  claim 28 , wherein said hypotube is formed from a metallic material comprising 316 or 304 stainless steel. 
     
     
         37 . The endovascular delivery system of  claim 28 , wherein said hypotube is formed from a biocompatible material selected from the group consisting of nitinol, cobalt-based alloy, platinum, gold, titanium, tantalum, niobium, and combinations thereof. 
     
     
         38 . The endovascular delivery system of  claim 28 , wherein the hypotube comprises an exterior surface having a surface finish of less than or equal to about 32 microinches RMS 
     
     
         39 . The endovascular delivery system of  claim 28 , wherein the tubular wall of the hypotube has a thickness from about 0.005 inches to about 0.020 inches. 
     
     
         40 . The endovascular delivery system of  claim 28 , wherein the slots have a kerf width from about 0.001 inches to about 0.003 inches. 
     
     
         41 . The endovascular delivery system of  claim 28 , wherein a longitudinal distance between adjacent slots is from about 0.010 inches to about 0.050 inches. 
     
     
         42 . The endovascular delivery system of  claim 28 , wherein the slots have edges that are rounded to a radius of about 0.005 inches or less. 
     
     
         43 . The endovascular delivery system of  claim 28 , wherein the outer tubular sheath comprises polytetrafluoroethylene. 
     
     
         44 . The endovascular delivery system of  claim 28 , wherein, when the hypotube is disposed within the outer tubular sheath, the hypotube has a torqueability from about 70% to about 100%, said torqueability being measured as percent of rotation of the distal end of the hypotube for a rotation amount at the proximal end of the hypotube when placed in a tortuous path. 
     
     
         45 . The endovascular delivery system of  claim 28 , wherein the first flexible portion of the hypotube has a bending radius of no more than about 1.5 inches before plastic deformation. 
     
     
         46 . The endovascular delivery system of  claim 28 , wherein the hole of the at least one end of the hypotube is disposed at a proximal portion of the hypotube to secure the hypotube to a proximal handle assembly. 
     
     
         47 . The endovascular delivery system of  claim 28 , wherein the hole of the at least one end of the hypotube is disposed at a distal portion of the hypotube to secure the hypotube to a distal cap of the hypotube.