Large-diameter introducer sheath having hemostasis valve and removable steering mechanism

Abstract

A catheter introducing system includes an introducer catheter comprising a flexible sheath having a hemostasis valve and an obturator having a steering mechanism operated by a proximal actuator handle. The catheter introducer system will usually be introduced with the obturator inside of the flexible sheath so that the obturator can effect steering by laterally deflecting the distal end of the combined sheath and obturator. Such catheter introducing systems are particularly useful for large diameter sheaths which are not readily introduced over guide wires. A first exemplary hemostasis valve comprises a compressed foam insert having an axial lumen therein. A second exemplary hemostasis valve comprises an elastomeric insert which receives and seals over the catheter.

What is claimed is:  
     
         1 . A catheter introducing system comprising: 
 a flexible sheath having a proximal end, a distal end, and a lumen extending therebetween; and    an obturator removably receivable in the lumen of the flexible sheath, said obturator having means actuable from a proximal end thereof for laterally deflecting at least a distal portion thereof.    
     
     
         2 . A catheter introducing system as in  claim 1 , wherein the obturator has an outer diameter which is at least 75% of the inner diameter of the sheath.  
     
     
         3 . A catheter introducing system as in  claim 2 , wherein the obturator has a tapered distal end which defines a smooth transition with the distal end of the sheath.  
     
     
         4 . A catheter introducing system as in  claim 3 , wherein the obturator has a length which is in the range from one to one and one-half times that of the flexible sheath.  
     
     
         5 . A catheter introducing system as in  claim 3 , wherein the obturator has a length which is at least twice that of the flexible sheath.  
     
     
         6 . A catheter introducing system as in  claim 1 , wherein the flexible sheath has a length in the range from about 30 cm to 60 cm and a lumen diameter in the range from about 4 mm to 10 mm and wherein the obturator has a length in the range from 35 cm to 65 cm and an outer diameter in the range from about 4 mm to 9 mm.  
     
     
         7 . A catheter introducing system as in  claim 6 , wherein the obturator comprises an elongate body having a region of enhanced flexibility over the distal length in the range from 3 cm to 6 cm.  
     
     
         8 . A catheter introducing system as in  claim 7 , wherein the region of enhanced flexibility is articulated.  
     
     
         9 . A catheter introducing system as in  claim 7 , wherein the flexible sheath has a region of enhanced flexibility over a distal length in the range from 5 cm to 15 cm.  
     
     
         10 . A catheter introducing system as in  claim 1 , wherein the deflecting means comprises a pull wire attached off center at the distal end of the obturator.  
     
     
         11 . A method for introducing a flexible sheath to a target location in a body lumen, said method comprising: 
 introducing the sheath to the body lumen;    advancing the sheath within the lumen toward the target location while laterally deflecting at least a distal portion of an obturator which is removably received in a lumen of the sheath; and    removing the obturator from the sheath to provide an access lumen through the sheath after reaching the target location.    
     
     
         12 . A method as in  claim 11 , wherein the laterally deflected distal portion of the obturator is positioned within a distal portion of the sheath while the sheath and obturator are advanced together.  
     
     
         13 . A method as in  claim 11 , wherein the sheath is advanced over the obturator after the obturator has been advanced toward the target location.  
     
     
         14 . A method as in  claim 11 , wherein the target location is the aorta and sheath and obturator are advanced through the subclavian, external carotid, or axillary artery and the aortic arch to the aorta.  
     
     
         15 . A method as in  claim 14 , wherein the sheath has a length in the range from 30 cm to 60 cm and an access lumen diameter in the range from about 5 mm to 10 mm.  
     
     
         16 . A method as in  claim 14 , further comprising expanding a member on the exterior of the sheath within the aorta to partially occlude blood flow.  
     
     
         17 . A method as in  claim 14 , further comprising introducing a vascular graft through the access lumen into the aorta, the right iliac, or the left iliac.  
     
     
         18 . A method as in  claim 17 , further comprising expanding a member on the exterior of the sheath within the vascular graft after said graft has been positioned at the target location in order to anchor the graft at said target location.  
     
     
         19 . An aortic introducer catheter comprising: 
 a flexible sheath having a proximal and, a distal end, and a lumen extending therebetween wherein the length between the proximal and distal ends is in the range from 30 cm to 60 cm and the lumen diameter is in the range from 5 mm to 10 mm, and    a hemostasis valve secured to the proximal end of the sheath.    
     
     
         20 . An aortic introducer catheter as in  claim 19 , wherein the flexible sheath has a region of enhanced flexibility over a distal length in the range from 5 cm to 15 cm.  
     
     
         21 . An aortic introducer catheter as in  claim 19 , further comprising an expandable member on the exterior of the sheath located at from 1 cm to 10 cm from the distal end of the sheath, wherein said expandable member partially occludes blood flow when expanded inside the aorta.  
     
     
         22 . A aortic introducer catheter as in  claim 19 , further comprising an expandable member at the distal end of the sheath, wherein said expandable member can be positioned within an aortic prosthesis for internal expansion.  
     
     
         23 . An aortic introducer catheter as in  claim 19 , wherein the flexible sheath comprises: 
 a tubular inner liner having a proximal end, a distal end, and a lumen therebetween;    a flat wire helical coil wrapped over an exterior surface of the tubular inner liner, said coil having spaced-apart adjacent turns; and    a plastic coating formed over the helical coil, penetrating into the space between adjacent turns of the coil, and bonded to the tubular inner liner.    
     
     
         24 . An aortic introducer catheter as in  claim 19 , wherein the hemostasis valve comprises: 
 a housing having an interior and axially aligned inlet and outlet ports; and    a compressible insert disposed within the interior of the housing, said insert including a polymeric foam body having an open axial lumen and an exterior geometry which is similar to but larger than the cavity in the housing, wherein the insert is confined within the cavity to close the lumen with said closed lumen being aligned between the inlet and outlet ports.    
     
     
         25 . A catheter sheath comprising: 
 a tubular inner liner having a proximal end, a distal end, and a lumen therebetween;    a flat wire helical coil wrapped over an exterior surface of the tubular inner liner, said coil having spaced-apart adjacent turns; and    a plastic coating formed over the helical coil, penetrating into the space between adjacent turns of the coil, and bonded to the tubular inner liner.    
     
     
         26 . A catheter sheath as in  claim 25 , wherein the tubular liner is composed of a material selected from the group consisting of polyurethane, polytetrafluoroethylene, fluorinated ethylene-propylene polymer, polyether block amide copolymer, polyamide, and polyethylene and has a wall thickness in the range from 0.08 mm to 0.15 mm.  
     
     
         27 . A catheter sheath as in  claim 25 , wherein the helical coil comprises a stainless steel ribbon having a width in the range from 0.5 mm to 1.5 mm and thickness in the range from 0.08 mm to 0.15 mm, wherein the ribbon is wrapped at from 5 turns to 15 turns per cm and wherein the spacing between adjacent turns is in the range from 0.5 mm to 1 mm.  
     
     
         28 . A catheter sheath as in  claim 25 , wherein the plastic coating is composed of a material selected from the group consisting of polyurethane, polyether block amide copolymer, polyethylene, and polyamide, and has a thickness measured from tubular inner liner in the range from 0.08 mm to 0.15 mm.  
     
     
         29 . A catheter sheath as in  claim 25 , having a region of enhanced flexibility over a distal length in the range from about 5 cm to 15 cm.  
     
     
         30 . A catheter sheath as in  claim 25 , having a soft tip free from the helical coil over a distal length in the range of 2 mm to 10 mm.  
     
     
         31 . A catheter sheath as in  claim 25 , further comprising a hemostasis valve secured to the proximal end of the sheath.  
     
     
         32 . A steerable obturator for use with a flexible catheter sheath, said obturator comprising: 
 a flexible body having a proximal end and tapered distal tip; and    means for laterally deflecting at least a distal portion of the flexible body.    
     
     
         33 . A steerable obturator as in  claim 32 , wherein the catheter body has a length in the range from 45 cm to 60 cm and an outer diameter in the range from 4 mm to 5 mm.  
     
     
         34 . A steerable obturator as in  claim 33 , wherein the catheter body has a region of enhanced flexibility over a distal length in the range from about 5 cm to 10 cm.  
     
     
         35 . A steerable obturator as in  claim 33 , wherein the region of enhanced flexibility is articulated.  
     
     
         36 . A steerable obturator as in  claim 32 , wherein the deflecting means comprises a pull wire attached off center at the distal end of the flexible body.  
     
     
         37 . A steerable obturator as in  claim 36 , wherein the deflecting means further comprises a handle assembly attached to the proximal end of the flexible body, wherein said handle assembly includes a first portion attached to the pull wire and a second portion attached to the flexible body, whereby relative movement of the two portions causes lateral deflection of the tip.  
     
     
         38 . A hemostasis valve comprising: 
 a housing having an interior cavity and axially aligned inlet and outlet ports; and    a compressible insert disposed within the interior cavity of the housing, said insert including a polymeric foam body having an open axial lumen and an exterior geometry which is similar to but larger than the cavity in the housing, wherein the insert is confined within the cavity to close the lumen with said closed lumen being aligned between the inlet and outlet ports.    
     
     
         39 . A hemostasis valve as in  claim 38 , further comprising a second valve element in series with the compressible insert.  
     
     
         40 . A hemostasis valve as in  claim 39 , wherein the second valve element is a duck bill or a slit disk structure.  
     
     
         41 . A hemostasis valve as in  claim 38 , wherein the lumen is coated with a lubricant.  
     
     
         42 . A hemostasis valve as in  claim 38 , wherein the lumen is coated with a protective layer.  
     
     
         43 . A hemostasis valve as in  claim 42 , wherein the coating material is selected from the group consisting of polyurethane and silicone.  
     
     
         44 . A hemostasis valve comprising: 
 a housing having an interior cavity and axially aligned inlet and outlet ports; and    an elastomeric insert within the interior cavity of the housing, said insert having a forwardly disposed conical face, wherein the face is radially split to permit passage of a catheter therethrough.    
     
     
         45 . A hemostasis valve as in  claim 41 , wherein the insert further includes an annular ring disposed proximally of the forwarding disposed face.