Steerable dilatation catheter

A steerable dilatation catheter comprising;

• a) an elongated torquable member including,
• an elongated, tubular element formed of high-strength material having proximal and distal extremities and an inner lumen extending along the length thereof in fluid communication with at least one inflation port for inflation fluid provided in the distal extremity thereof, and
• an elongated guide element secured to the distal extremity of the elongated tubular element;
• b) an inflatable balloon having proximal and distal ends and an interior and being secured at both the proximal end and distal ends thereof to the elongated torquable member to prevent the relative rotational movement therebetween with the interior of the inflatable balloon being in fluid communication with the inner lumen of the elongated tubular member through at least one discharge port therein;
• c) an elongated flexible member disposed about a portion of the elongated guide element which extends distally of the balloon;
• and
• d) means on the proximal extremity of the torquable member to axially rotate the torquable member.

A balloon catheter, comprising:

• an elongate hollow, thin wall, tube having a lumen extending therethrough from a proximal end to a distal end;
• a hollow, flexible torque transmitting shaft having a first end connected to the distal end of the tube and having a flow lumen therethrough which is in communication with the lumen of the tube;
• an elongate core member extending distally from a second end of the shaft;
• and
• an inflatable balloon surrounding the core member and having a proximal end bonded to the second end of the shaft and a distal end bonded to the core member, an interior of the balloon being in communication with the flow lumen.

A balloon catheter comprising:

• a main shaft having a first inflation lumen extending therethrough from a proximal end to a distal end;
• a secondary shaft having a proximal end connected to the distal end of the main shaft and having a second inflation lumen extending therethrough from the proximal end to a distal end;
• the second inflation lumen being connected to the first inflation lumen, the secondary shaft having greater flexibility than and substantially similar torque transmitting characteristics to the main shaft;
• an elongated core member extending distally from the distal end of the secondary shaft;
• and
• an inflatable balloon surrounding the core member and having a proximal end connected to the distal end of the secondary shaft, a distal end connected to the core member, and an interior in communication with the second inflation lumen.

A method of dilating a stenosis within the arterial system of a patient comprising:

• a) introducing into the patient's vasculature a low-profile steerable dilatation catheter comprising:
• an elongated tubular member formed of high-strength material having proximal and distal extremities, at least one discharge port in the distal extremity and an inner lumen extending therein in fluid communication with at least one discharge port in the distal extremity,
• an elongated flexible guide element having proximal and distal ends and being secured by its proximal end to the distal extremity of the elongated tubular member,
• an inflatable balloon having proximal and distal ends and being disposed about the elongated flexible guide element, with the proximal end of the balloon secured to the distal extremity of the elongated member proximally of at least one discharge port therein to facilitate the passage of inflation fluid from the inner lumen of the elongated tubular member into the interior of the inflatable balloon and the distal end of the balloon sealingly secured about the elongated flexible guide element to prevent loss of inflation fluid and to prevent relative rotational movement between the proximal and distal ends of the balloon,
• an elongated flexible member disposed about and secured to the elongated flexible guide element and extending distally of the balloon, and
• torque means, including a removable hub, to axially rotate the elongated tubular member and the elongated flexible guide element, secured to the proximal end of the elongated tubular member which adapted to be connected to a source of inflation fluid;
• b) advancing the catheter through the patient's vasculature until the balloon crosses a stenosis;
• c) inflating the balloon on the distal end of the catheter to dilate a stenosis;
• d) deflating the balloon;
• e) removing the removable hub in the proximal end of the elongated tubular member;
• f) securing an exchange wire to the proximal end of the elongated tubular member;
• g) advancing over the exchange and elongated tubular member a conventional dilatation catheter having a dilatation balloon on the distal portion thereof with an inflated diameter larger than the inflated diameter of the low-profile steerable catheter until the balloon on the conventional dilatation catheter is disposed across the stenosis;
• and
• h) inflating the balloon on the conventional dilatation catheter to further dilate the previously dilated stenosis.