Balloon catheter with distal guide wire lumen

In an elongate dilatation catheter of the type that can be slidably moved along a guide wire that can extend past a distal end of the catheter, wherein the guide wire is received in a guide wire lumen of the catheter, the guide wire extending from a distal guide wire lumen opening to a proximal guide wire lumen opening disposed in a portion of the catheter that is spaced distally from a proximal end of the catheter, the dilatation catheter including an inflatable balloon and an inflation lumen extending through the catheter separate from the guide wire lumen, an improvement comprising:

• a tube formed from a relatively stiff material composition, the tube defining a first shaft section having a proximal end and a distal end;
• a second shaft section disposed distally of the first shaft section, the second shaft section being relatively more flexible than the first shaft section and having the guide wire lumen extending through a portion thereof;
• and
• an intermediate section disposed between the first shaft section and the second shaft section, the intermediate section including an intermediate member adjacent the proximal guide wire lumen opening which is of diminished dimension relative to the tube such that at least a portion of the intermediate section is more flexible than the first shaft section and less flexible than the second shaft section.

In an elongate dilatation catheter which has an inflatable balloon and a inflation lumen extending through the catheter, wherein the catheter is of the type that can be slidably moved along a guide wire that can extend east a distal end of the catheter through a guide wire lumen of the catheter, wherein the guide wire lumen is separate from the inflation lumen and extends from a distal guide wire lumen opening to a proximal guide wire lumen opening located in a portion of the catheter that is spaced distally from a proximal end of the catheter so that the guide wire lumen is shorter than the inflation lumen, an improvement comprising:

• a first proximal shaft section of the catheter defined by a tubing of relatively rigid material;
• a second shaft section disposed distally of the first shaft section, the second shaft section being relatively more flexible than the first shaft section;
• and
• a transition section disposed between the first shaft section and the second shaft section and including a metallic element of diminished dimension relative to the tubing, the transition section extending adjacent to the proximal guide wire lumen opening and having an intermediate rigidity to provide a stepped transition between the first shaft section and the second shaft section.

In an elongate dilatation catheter which has an inflatable balloon and an inflation lumen extending through the catheter, wherein the catheter is of the type that can be slidably moved along a guide wire which can extend past a distal end of the catheter through a guide wire lumen of the catheter, wherein the guide wire lumen is separate from the inflation lumen and extends from a distal guide wire lumen opening to a proximal guide wire lumen opening disposed in a portion of the catheter that is spaced distally from a proximal end of the catheter so that the guide wire lumen is shorter than the inflation lumen, an improvement comprising:

• a first proximal shaft section of the catheter defined by a tubing of relatively rigid material;
• a second shaft section disposed distally of the first shaft section, the second shaft section being relatively more flexible than the first shaft section;
• and
• a transition section disposed between the first shaft section and the second shaft section and extending adjacent to the proximal guide wire lumen opening, the transition section having decreased rigidity relative to the tubing to provide a stepped transition in flexibility between the first shaft section and the second shaft section.

In an elongate dilatation catheter of the type that has a relatively long proximal shaft section, a second shorter distal shaft section disposed distally of the first shaft section, an inflatable balloon attached to the distal end of the second shaft section wherein the first and second shaft sections have an inflation lumen defined therethrough so that the balloon is in fluid communication with the inflation lumen, and wherein the catheter is of the type that can be slidably moved along a guide wire which can extend through a guide wire lumen of the catheter, the guide wire lumen being separate from the inflation lumen and extending from a distal guide wire lumen opening at the distal end of the catheter to a proximal guide wire lumen opening adjacent the proximal end of the second shaft section so that the guide wire lumen is shorter than the inflation lumen, an improvement comprising:

• the first proximal shaft section of the catheter defined by a tubing of relatively rigid material;
• the second shaft section of the catheter being relatively more flexible than the first shaft section and having a relatively short reinforced proximal portion and a relatively long nonreinforced distal portion;
• and
• the reinforced proximal portion including a transition member disposed adjacent to the proximal guide wire lumen opening and extending distally along the second shaft section to provide a reinforcement therefor, the transition member including a metallic element having a uniform reduced dimension relative to the tubing as it extends distally along the catheter to provide a stepped transition in rigidity in the distal direction, the transition member having a distal terminal end spaced from the balloon by the length of the nonreinforced distal portion of the second shaft section.