Collapsible sheath and tapered dilator for tissue puncture access

Abstract

A tissue puncture access assembly that includes a sheath and a dilator. The sheath is operable between an expanded position with a first maximum outer diameter, and a collapsed position with a second maximum outer diameter that is less than the first maximum outer diameter. The dilator is insertable through the sheath and has a leading end positionable distal of a distal end of the sheath. The sheath is operated into the collapsed position prior to and during insertion with the dilator into a tissue puncture. The sheath is operated into the expanded position once positioned in the tissue puncture.

1 - 20 . (canceled) 
     
     
         21 . A tissue puncture access assembly, comprising:
 a sheath having an expanded position with a first minimum inner diameter, the sheath having a collapsed position with a second minimum inner diameter, the second minimum inner diameter being less than the first minimum inner diameter;   a dilator insertable through the sheath and having a leading end positionable distal of a distal end of the sheath, the leading end having an outer diameter, the dilator having a proximal end, the proximal end having a hub;   wherein the second inner diameter of the sheath substantially matches the outer diameter of the leading end of the dilator.   
     
     
         22 . The tissue puncture access assembly of  claim 21 , wherein the dilator includes a taper at the leading end. 
     
     
         23 . The tissue puncture access assembly of  claim 21 , wherein the sheath changes shape from the collapsed position to the expanded position in first and second stages, the first stage including shortening in an axial direction, and the second stage including expansion in a radial direction. 
     
     
         24 . The tissue puncture access assembly of  claim 21 , wherein the sheath is operable between the expanded and collapsed positions using a braided construction. 
     
     
         25 . The tissue puncture access assembly of  claim 24 , wherein the braided construction is actuated by one of twisting, pushing, pulling or lever action. 
     
     
         26 . The tissue puncture access assembly of  claim 21 , wherein the sheath is operable between expanded and collapsed positions using a coil member. 
     
     
         27 . A tissue puncture access assembly, comprising:
 a collapsible sheath having a variable outer diameter and a lumen having a variable inner diameter;   a dilator insertable through the lumen of the collapsible sheath, the dilator having a proximal end integrated with a hub;   wherein the collapsible sheath and dilator are insertable together through a tissue puncture with the collapsible sheath is in a collapsed position with a reduced outer diameter, and operable into an expanded position with an increased outer diameter when positioned in the tissue puncture to enlarge the tissue puncture.   
     
     
         28 . The tissue puncture access assembly of  claim 27 , wherein an outer diameter of the dilator substantially matches the variable inner diameter of the collapsible sheath. 
     
     
         29 . The tissue puncture access assembly of  claim 27 , wherein the dilator includes a tapered distal end positionable distal of a distal end of the collapsible sheath when the collapsible sheath is in the collapsed position. 
     
     
         30 . The tissue puncture access assembly of  claim 27 , wherein the collapsible sheath is moved between expanded and collapsed positions to change the variable outer diameter using a rotatable collapsing mechanism. 
     
     
         31 . The tissue puncture access assembly of  claim 27 , wherein the collapsible sheath includes a coil member operable to change the collapsible sheath between the collapsed position and the expanded position. 
     
     
         32 . The tissue puncture access assembly of  claim 27 , wherein the outer diameter of the dilator substantially matches the outer diameter of the collapsible sheath when the collapsible sheath is in the collapsed position. 
     
     
         33 . The tissue puncture access assembly of  claim 27 , wherein the dilator includes a stepped construction that permits collapsing of the sheath into the collapsed position. 
     
     
         34 . The tissue puncture access assembly of  claim 27 , wherein the dilator comprises a body portion, the body portion insertable through the lumen of the collapsible sheath, the body portion having a variable outer diameter. 
     
     
         35 . A method of accessing a tissue puncture, comprising:
 providing a collapsible sheath and a dilator, the dilator having a proximal end, the proximal end comprising a hub, the hub being movable relative to the collapsible sheath;   advancing the dilator through the collapsible sheath until a distal end of the dilator extends distal of the collapsible sheath;   orienting the collapsible sheath into a collapsed position around the dilator;   advancing the collapsible sheath and dilator through the tissue puncture with the collapsible sheath in the collapsed position;   orienting the collapsible sheath into an expanded position to dilate the tissue puncture.   
     
     
         36 . The method of  claim 35 , wherein operating the collapsible sheath into the collapsed position includes at least one of reducing an outer diameter of the collapsible sheath and increasing a length of the collapsible sheath. 
     
     
         37 . The method of  claim 35 , wherein operating the collapsible sheath into the collapsed position includes changing a length of the collapsible sheath and changing an outer diameter of the collapsible sheath. 
     
     
         38 . The method of  claim 35 , wherein operating the collapsible sheath into an expanded position includes rotating one end of the collapsible sheath relative to an opposite end of the collapsible sheath. 
     
     
         39 . The method of  claim 35 , further comprising orienting the collapsible sheath into the collapsed position around the dilator after dilating the tissue puncture, and withdrawing the collapsible sheath and dilator from the tissue puncture. 
     
     
         40 . The method of  claim 35 , wherein orienting the collapsible sheath into a collapsed position around the dilator comprises collapsing the collapsible sheath to a diameter substantially matching an outer diameter of the distal end of the dilator.