Fixed-wire dilatation balloon catheter

A catheter for use in angioplasty, the catheter comprising:

• a two-piece torque transmitting catheter shaft which includes:
• (a) a proximal section defined by an elongate, flexible metallic tube having an interior passage extending from a proximal end to a distal end, with the tube having a longitudinally extending bonding region formed only in a portion of a side wall of the tube adjacent its distal end;
• and
• (b) a distal section defined by an elongate, flexible metallic core, the core having a first outer diameter, at its proximal end, which is smaller than an inner diameter of the distal end of the tube and the core having a second, smaller outer diameter adjacent its distal end, with the core having its proximal end positioned in the bonding region and fixedly connected to the tube to extend distally therefrom;
• an elongate, flexible waist tube sealably connected to the tube at a second bonding region spaced proximally from the first bonding region, the waist tube extending distally beyond the distal end of the tube about the core to define a distal interior passage in fluid communication with the interior passage of the tube for fluid flow longitudinally through the distal end of the tube, with a distal end of the waist tube terminating proximally of the distal end of the core;
• and
• an inflatable balloon member having a proximal end sealably connected to the distal end of the waist tube at a third bonding region and having a distal end sealably connected to the core, with the balloon member extending around the core and having an interior in fluid communication with the distal interior passage of the waist tube.

A self-venting balloon catheter comprising:

• a catheter shaft having a proximal end, a distal end, and an inflation lumen extending therethrough;
• an inflatable balloon having a proximal end and a distal end, with the proximal end of the balloon being connected to the distal end of the catheter shaft so that an interior of the balloon is in fluid communication with the inflation lumen;
• a torque transmissive core having a proximal end and a distal end, with the core having its proximal end bonded to the distal end of the shaft and extending distally therefrom through the interior of the balloon and the core having its distal end bonded to the balloon;
• and
• means for defining an air venting passage extending proximally from a distal portion of the interior of the balloon to an outlet just proximal of the proximal end of the balloon for venting air from the interior of the balloon to outside the catheter but inhibiting escape of liquid from the balloon.

A method of making a balloon catheter comprises the steps of:

• providing a thin-walled tube as a shaft;
• deforming a portion of a side wall of the tube to fashion a formed recess of reduced diameter adjacent a distal end of the tube, with the recess being open at the distal end of the tube;
• positioning a proximal end of a core member in the formed recess;
• bonding the proximal end of the core member to the tube, and
• attaching an inflation balloon member over the core member so that a proximal segment of the balloon member is connected to the tube and a distal segment of the balloon member is connected to the core member.