Catheter for balloon angioplasty

Claim 1

A catheter for balloon angioplasty comprising: a flexible shaft having a sealed hollow passage defined therein and having a first proximal end and a second distal end, both said ends being open, said flexible shaft being a coated wire wound member, said coating being fluid impervious and extending along substantially the entire length of the wire wound member, the wire wound member being substantially round in cross-section and resistant to flattening in cross-section when said flexible shaft is bent along the length thereof in the tortuous path of a coronary artery, allowing close tolerances for a member that may be inserted therein, the coated wire wound member inherently having high column strength providing pushability while maintaining a high degree of flexibility and being resistant to a preset in overall shape when the catheter is coiled for storage; a core means movably, removably and substantially contained within said flexible shaft, said core means having a first proximate end and a second distal end and having a first flexible portion extending from said first proximate end and a second flexible portion terminating in said second distal end of said core means, said second flexible portion being of greater flexibility than said first flexible portion, said second flexible portion having a variable core strength along the length thereof from greater to lesser strength extending toward the second distal end of said core means, said second flexible portion being tapered along the length thereof such that essentially all of said second flexible portion can generally be extended within a coronary artery to maximize the variable stiffness of said catheter, the combination of the core means and the coated wire wound member providing variable trackability, pushability and flexibility of said catheter; a flexible guide wire fixed to and further axially extending from the second distal end of said core means; and an inflatable member having a non-inflatable sheath covering an external surface of said flexible shaft near the second distal end of said flexible shaft and further including means for inflating said inflatable member.

Claim 6

A method of performing a combined fixed wire and movable wire angioplasty including the steps of: (a) inserting a catheter in a vascular tree, said catheter including a flexible shaft having a sealed hollow passage defined therein and having a first proximal end and a second distal end, both said ends being open, said flexible shaft being a coated wire wound member, said coating being fluid impervious and extending along substantially the entire length of the wire wound member, the wire wound member being substantially round in cross-section and resistant to flattening in cross-section when said flexible shaft is bent along the length thereof in the tortuous path of a coronary artery, allowing close tolerances for a member that may be inserted therein, the coated wire wound member inherently having high column strength providing pushability while maintaining a high degree of flexibility and being resistant to a preset in overall shape when the catheter is coiled for storage, said catheter including a core means movably, removably and substantially contained within said flexible shaft, said core means having a first proximate end and a second distal end and having a first flexible portion extending from said first proximate end and a second flexible portion terminating in said second distal end of said core means, said second flexible portion being of greater flexibility than said first flexible portion, said second flexible portion having a variable core strength along the length thereof from greater to lesser strength extending toward the second distal end of said core means, said second flexible portion being tapered along the length thereof such that essentially all of said second flexible portion can generally be extended within a coronary artery to maximize the variable stiffness of said catheter, the combination of the core means and the coated wire wound member providing variable trackability, pushability and flexibility of said catheter, said catheter including a flexible guide wire fixed to and further axially extending from the second distal end of said core means, said catheter including an inflatable member having an integral non-inflatable sheath covering an external surface of said flexible shaft near the second distal end of said flexible shaft and further including means for inflating said inflatable member; and (b) moving said second flexible portion of said core means axially relative to said second distal end of said flexible shaft, extension of the second flexible portion relative to the second distal end of said flexible shaft increasing pushability of the catheter and decreasing flexibility and trackability, retraction of said second flexible portion from such extended position increasing flexibility and trackability of the catheter with an accompanying decrease in pushability.

Claim 7

A method of performing a combined fixed wire and movable wire angioplasty including the steps of: (a) inserting a catheter in a vascular tree, said catheter including a flexible shaft having a sealed hollow passage defined therein and having a first proximal end and a second distal end, both said ends being open, said flexible shaft being a coated wire wound member, said coating being fluid impervious and extending along substantially the entire length of the wire wound member, the wire wound member being substantially round in cross-section and resistant to flattening in cross-section when said flexible shaft is bent along the length thereof in the tortuous path of a coronary artery, allowing close tolerances for a member that may be inserted therein, the coated wire wound member inherently having high column strength providing pushability while maintaining a high degree of flexibility and being resistant to a preset in overall shape when the catheter is coiled for storage, said catheter including a core means movably, removably and substantially contained within said flexible shaft, said core means having a first proximate end and a second distal end and having a first flexible portion extending from said first proximate end and a second flexible portion terminating in said second distal end of said core means, said second flexible portion being of greater flexibility than said first flexible portion, said second flexible portion having a variable core strength along the length thereof from greater to lesser strength extending toward the second distal end of said core means, said second flexible portion being tapered along the length thereof such that essentially all of said second flexible portion can generally be extended within a coronary artery to maximize the variable stiffness of said catheter, the combination of the core means and the coated wire wound member providing variable trackability, pushability and flexibility of said catheter, said catheter including a flexible guide wire fixed to and further axially extending from the second distal end of said core means, said catheter including an inflatable member having an integral non-inflatable sheath covering an external surface of said flexible shaft near the second distal end of said flexible shaft and further including means for inflating said inflatable member; and (b) moving said second flexible portion of said core means axially relative to said second distal end of said flexible shaft, extension of the second flexible portion relative to the second distal end of said flexible shaft increasing pushability of the catheter and decreasing flexibility and trackability, retraction of said second flexible portion from such extended position increasing flexibility and trackability of the catheter with an accompanying decrease in pushability.