Steerable dilatation catheter

Abstract

Low profile dilation catheter and method of manufacturing the same for use in percutaneous transluminal coronary angioplasty. The catheter has an inflatable balloon for dilating stenotic lesions, and an integral guide wire by which the catheter can be steered into the artery system.

I claim: 
     
       1. In a dilatation catheter, an elongate flexible plastic tubular member having proximal and distal ends and an axially extending flow passage extending therethrough, an inflatable balloon of flexible plastic carried by the tubular member and disposed near the distal end of the tubular member and having its interior in communication with the flow passage, a continuous guide wire extending through the flow passage, the balloon and the distal end of the tubular member, and means bonding the distal end of the tubular member directly to the guide wire to form a bond so that the guide wire is secured to the distal extremity of the tubular member. 
     
     
       2. The dilatation catheter of claim 1 wherein the balloon is formed as an integral part of the tubular member. 
     
     
       3. The dilatation catheter of claim 1 together with a vent tube extending through the flow passage in the tubular member and into the interior of the balloon. 
     
     
       4. The dilatation catheter of claim 1 wherein the guide wire comprises a hollow wire having an axially extending passageway and a port which communicates with the passageway and the balloon chamber for venting the chamber. 
     
     
       5. The dilatation catheter of claim 1 wherein the balloon is sealed to the guide wire with an adhesive. 
     
     
       6. The dilatation catheter of claim 1 together with a flexible coil secured to the distal extremity of the guide wire. 
     
     
       7. The dilatation catheter of claim 6 wherein the flexible coil is formed of a radiopaque material. 
     
     
       8. In a catheter for dilating a lesion in the cardiovascular system, an elongate flexible plastic tubular member having proximal and distal ends and an axially extending flow passage, an inflatable balloon of flexible plastic carried by the tubular member adjacent the distal end of the tubular member and having its interior in fluid communication with the flow passage in the tubular member, a metal guide wire having a shaft which extends through the flow passage in the tubular member and into the interior of the balloon, means directly bonding the distal end of the tubular member to the guide wire, means connected to the proximal end of the guide wire for rotating the same to steer the catheter into the cardiovascular system, and means connected to the proximal end of the tubular member for introducing a pressurized fluid into the flow passage to inflate the balloon. 
     
     
       9. The catheter of claim 8 wherein the guide wire includes a flexible coil affixed to the shaft near the distal end of the tubular member and extends beyond the tubular member to form a flexible tip. 
     
     
       10. The catheter of claim 9 wherein the distal end portion of the guide wire shaft extends axially into the coil and is tapered to provide a gradual transition in flexibility between the shaft and the coil. 
     
     
       11. The catheter of claim 10 wherein the shaft terminates prior to the distal end of the coil together with a flexible safety wire extending between the shaft and the distal end of the coil and means securing said safety wire to the shaft and to the distal end of the coil. 
     
     
       12. The catheter of claim 9 wherein the distal end of the coil is ball-like. 
     
     
       13. The catheter of claim 11 wherein the means securing the safety wire to the distal end of the coil has a ball-like configuration. 
     
     
       14. The catheter of claim 9 together with a marker of radiopaque material affixed to the guide wire within the balloon catheter. 
     
     
       15. The catheter of claim 9 wherein the flexible helical coil is formed of a radiopaque material. .Iadd. 
     
     
       16.  A steerable, low-profile dilatation catheter comprising: an elongate flexible tubular member having a fluid flow passage extending therethrough;   an inflatable balloon disposed near the distal end of the tubular member and having its interior in communication with the fluid flow passage;   a guide element fixed within the dilatation catheter having a tapered section which extends through the interior of the balloon and projects out the distal end thereof;   a helical coil disposed about the outwardly projecting portion of the tapered section;   means to bond the helical coil to the outwardly projecting portion of the tapered section; and   means to seal the distal end of the balloon. .Iaddend. .Iadd.17. The steerable, low profile dilatation catheter of claim 16 wherein control means are provided at the proximal end of the catheter to steer the distal portion thereof. .Iaddend. .Iadd.18. The steerable, low profile dilatation catheter of claim 16 wherein a safety ribbon extends from the tapered section of the guide element to the distal end of the helical coil.   
     
     
        .Iaddend. .Iadd.19.  The steerable, low profile dilatation catheter of claim 16 wherein means are provided to vent air from the interior of the 
     
     
        balloon through the distal end thereof. .Iaddend. .Iadd.20.  A dilatation catheter comprising: (a) a first tubular member having an inner lumen extending therethrough;   (b) an inflatable balloon disposed near the distal end of the tubular member having its interior in fluid communication with the inner lumen of the tubular member;   (c) a second tubular member having an inner lumen extending therethrough which extends through the interior of the balloon and having at least one opening therein distally of the balloon with the distal end of the balloon sealed about the second tubular member to prevent the loss of inflation liquid from the interior of the balloon; and   (d) means to vent air from within the interior of the balloon through the inner lumen of the second tubular member. .Iaddend. .Iadd.21. The dilatation catheter of claim 20 wherein the means to vent air includes an opening in a portion of the second tubular member disposed within the interior of the balloon. .Iaddend. .Iadd.22. The dilatation catheter of claim 20 wherein the second tubular member is hypotubing formed from stainless steel. .Iaddend. .Iadd.23. A guide wire adapted to be positioned within an inner lumen of a balloon dilatation catheter comprising:   (a) an elongated hollow wire element having an inner lumen extending along the interior thereof and having an opening at or near the distal end in fluid communication with the lumen which facilitates pressure detection of the fluids on the exterior of the guide wire;   (b) means disposed on the proximal extremity of the elongated hollow wire element to torque the wire element; and   (c) a flexible coil member disposed about the distal portion of the hollow wire member providing access for fluid on the exterior thereof to an opening at or near the distal end of the hollow wire element. .Iaddend.   
     
     
        .Iadd.24.  The guide wire of claim 23 positioned within an inner lumen of a balloon dilatation catheter with the distal portion of the balloon on the dilatation catheter being sealed about the distal portion of the hollow wire element disposed therein. .Iaddend.