System for a wire-lumen free balloon catheter

Abstract

The invention relates to a low profile lumen free balloon catheter and a system for advancing the lumen free balloon from a build wire to a wire guide. The low profile balloon lacks an internal wire guide cannula between the catheter shaft and the soft tip. A releasable engagement is provided to connect/disconnect the build wire to/from the wire guide. A soft tip seals around the wire guide following advancement of the balloon catheter over the wire guide.

1 . A system for advancing a low profile balloon catheter onto a wire guide comprising:
 (a) a balloon catheter arrangement comprising
 (i) an elongate shaft having a fluid supply lumen, a proximal end, and a distal end; 
 (ii) a balloon having an internal cavity, a proximal portion and a distal neck, the proximal portion of the balloon being mounted on the distal end of the elongate shaft; and 
 (iii) a soft tip having a proximal end, a distal end, and a distal opening, wherein the proximal end of the soft tip is joined to the distal neck of the balloon; 
 wherein the balloon and soft tip define a combined internal cavity communicating with the fluid supply lumen, the combined internal cavity holding a first balloon volume when the balloon and the soft tip are filled with a first fluid volume; and 
   (b) a build wire having a first portion disposed within the elongate shaft, a second portion disposed within the combined internal cavity, and a distal end projecting through the distal opening of the soft tip, the second portion of the build wire defining a build wire volume;   wherein the first balloon volume consists of the first fluid volume plus the build wire volume.   
     
     
         2 . The system of  claim 1  wherein the second portion of the build wire has an outer surface in direct communication with a fluid in the combined internal cavity. 
     
     
         3 . The system of  claim 1  wherein the balloon catheter arrangement lacks an internal wire guide cannula around the second portion of the build wire. 
     
     
         4 . The system of  claim 1  further comprising:
 a wire guide having a proximal end and a distal end, the proximal end of the wire guide being adapted to form a releasable engagement with the distal end of the build wire; 
 wherein the releasable engagement, the balloon, and the soft tip are adapted to permit advancement of the balloon and soft tip from the build wire over the releasable engagement onto the wire guide. 
 
     
     
         5 . The system of  claim 4  wherein the releasable engagement comprises a frictional engagement. 
     
     
         6 . The system of  claim 4  wherein the releasable engagement comprises a magnetic engagement. 
     
     
         7 . The system of  claim 4  wherein the releasable engagement is a threaded engagement. 
     
     
         8 . The system of  claim 4  wherein the distal end of the build wire is configured as a bore hole adapted to accept the proximal end of the wire guide. 
     
     
         9 . The system of  claim 8  wherein the bore hole is tapered. 
     
     
         10 . The system of  claim 8  wherein the bore hole has a frictive inner surface. 
     
     
         11 . The system of  claim 8  wherein the distal end of the build wire has a tapered outer surface. 
     
     
         12 . A low profile balloon catheter system comprising:
 (a) a balloon catheter arrangement comprising
 (i) an elongate shaft having a fluid supply lumen, a proximal end, and a distal end; 
 (ii) a balloon having an internal cavity, a proximal portion and a distal neck, the proximal portion of the balloon being mounted on the distal end of the elongate shaft; and 
 (iii) a soft tip having a proximal end, a distal end, and a distal opening, wherein the proximal end of the soft tip is joined to the distal neck of the balloon; 
 wherein the balloon and soft tip define a combined internal cavity communicating with the fluid supply lumen, the combined internal cavity holding a second balloon volume when the balloon and the soft tip are filled with a second fluid volume; and 
   (b) a wire guide having a first portion disposed within the elongate shaft, a second portion disposed within the combined internal cavity, and a distal end projecting through the distal opening of the soft tip, the second portion of the wire guide defining a wire guide volume;   wherein the second balloon volume consists of the second fluid volume plus the wire guide volume.   
     
     
         13 . The system of  claim 12  wherein the distal end of the soft tip forms a sealing engagement around the wire guide. 
     
     
         14 . (canceled) 
     
     
         15 . The system of  claim 13  wherein the sealing engagement comprises a silicone seal. 
     
     
         16 . The system of  claim 12  wherein the soft tip further comprises:
 a substantially circumferential flap extending from the proximal end of the soft tip to the interior of the soft tip, the flap adapted to sealingly engage the wire guide. 
 
     
     
         17 - 20 . (canceled) 
     
     
         21 . A method of advancing a wire-lumen free balloon catheter onto a wire guide comprising:
 positioning a wire guide in a patient, the wire guide comprising a proximal end;   connecting the proximal end of the wire guide to a distal end of a build wire; and   advancing a balloon having an internal cavity with no internal wire guide cannula over the distal end of the build wire and fully onto the wire guide.   
     
     
         22 . The method of  claim 21 , wherein the proximal end of the wire guide connects to the distal end of the build wire by a releasable engagement. 
     
     
         23 . The method of  claim 21  further comprising disconnecting the distal end of the build wire from the proximal end of the wire guide. 
     
     
         24 . The method of  claim 21 , wherein the balloon further comprises a distal neck, the distal neck being joined to a proximal end of a soft tip wherein the balloon and soft tip together define a combined internal cavity that lacks the internal wire guide cannula. 
     
     
         25 . The method of  claim 21 , wherein the balloon further comprises a distal neck, the distal neck being joined to a proximal end of a soft tip wherein the balloon and soft tip together define a combined internal cavity that holds a balloon volume when disposed over a portion of the wire guide and filled with a fluid volume,
 wherein the balloon volume consists of the fluid volume plus the volume of the portion of the wire guide disposed within the combined internal cavity.