Guidewire/inflation tube locking apparatus and method of use

• US 5,658,309 A
• Filed: 05/01/1995
• Issued: 08/19/1997
• Est. Priority Date: 05/01/1995
• Status: Expired due to Fees

• Current Assignee: Medtronic Ave Incorporated (Medtronic Plc)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Douk, Nareak, Berthiaume, William A.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): TRUONG, KEVIN THAO
• Application Number:
  US08/431,546
• Time in Patent Office: 841 Days
• Field of Search: 606/194, 606/192, 606/193, 604/96, 604/102, 604/121, 604/905
• US Class Current: 606/192
• CPC Class Codes: A61M 2025/0175 having telescopic features, interengaging nestable members movable in relations to one another
• CPC Class Codes: A61M 2025/0183 Rapid exchange or monorail catheters
• CPC Class Codes: A61M 2025/09008 having a balloon
• CPC Class Codes: A61M 2025/09125 Device for locking a guide wire in a fixed position with respect to the catheter or the human body
• CPC Class Codes: A61M 25/0097 characterised by the hub connectors A61M39/10
• CPC Class Codes: A61M 25/0169 Exchanging a catheter while keeping the guidewire in place
• CPC Class Codes: A61M 25/09 Guide wires
• CPC Class Codes: A61M 25/104 used for angioplasty

Abstract

A locking apparatus for use with a catheter which includes a catheter body, first and second slidable components which are slidable with respect to the catheter body, and a hub disposed at the proximal end of the catheter body, and a method of using the locking apparatus. The locking apparatus includes a locking device engageable with the hub for locking the first slidable component in a fixed position relative to the hub, and an extension member that is integral with the hub and engageable with the locking device for locking the second slidable component in a fixed position relative to the hub.

Claims

1. A locking apparatus, in combination with a telescoping catheter which includes an elongated inflation shaft, a plurality of telescoping tubes slidably mounted on said inflation shaft, a guidewire extending the length of said telescoping catheter, and a hub disposed at the proximal end of one of said telescoping tubes and having an inner wall defining a central port through which extend said inflation shaft and said guidewire, said locking apparatus comprising:

locking means engageable with said hub for locking said guidewire in a fixed position relative to said hub; and

extension means integral with said hub engageable with said locking means for locking said inflation shaft in a fixed position relative to said hub.

2. A locking apparatus, in combination with a telescoping catheter which includes an elongated inflation shaft, a plurality of telescoping tubes slidably mounted on said inflation shaft, a guidewire extending the length of said telescoping catheter, and a hub disposed at the proximal end of one of said telescoping tubes and having an inner wall defining a central port through which extend said inflation shaft and said guidewire, said locking apparatus comprising:

an extension member integral with said hub; and

a locking device having a distal end, a proximal end, an outer wall and an inner wall defining a locking lumen extending between said distal and proximal ends, said locking device slidably mounted on said inflation shaft so that said inflation shaft extends through said locking lumen, said distal end of said locking device engageable with said central port of said hub such that said outer wall of said locking device and said inner wall of said hub lock said guidewire in a fixed position relative to said hub, and said distal end of said locking lumen engageable with said extension member such that said extension member and said inner wall of said locking device lock said inflation shaft in a fixed position relative to said hub.

3. A locking apparatus, in combination with a catheter which includes a catheter body, first and second slidable components which are slidable with respect to the catheter body, and a hub disposed at the proximal end of the catheter body and having an inner wall defining a central port through which extend said first and second slidable components, said locking apparatus comprising:

an extension member integral with said hub and extending proximally from said hub, said extension member having a securing member disposed at its proximal end; and

a locking device having a distal end, a proximal end, an outer wall and an inner wall defining a lumen extending between said distal and proximal ends, said locking device slidably mounted on said extension member so that said second slidable component extends through said lumen, said distal end of said locking device engageable with said central port of said hub such that said outer wall of said locking device and said inner wall of said hub lock said first slidable component in a fixed position relative to said hub, and said proximal end of said inner wall defining said lumen in said locking device engageable with said securing member disposed at said proximal end of said extension member such that said securing member and said inner wall of said locking device lock said second slidable component in a fixed position relative to said hub.

4. A locking apparatus, in combination with a telescoping catheter which includes an elongated inflation shaft, a plurality of telescoping tubes slidably mounted on said inflation shaft, a guidewire extending the length of said telescoping catheter, and a hub disposed at the proximal end of one of said telescoping tubes and having an inner wall defining a central port through which extend said inflation shaft and said guidewire, said locking apparatus comprising:

an extension member integral with said hub and extending proximally from said hub, said extension member having a securing member disposed at its proximal end; and

a locking device having a distal end, a proximal end, an outer wall and an inner wall defining a lumen extending between said distal and proximal ends, said locking device slidably mounted on said extension member so that said inflation shaft extends through said locking lumen, said distal end of said locking device engageable with said central port of said hub such that said outer wall of said locking device and said inner wall of said hub lock said guidewire in a fixed position relative to said hub, and said proximal end of said inner wall defining said lumen in said locking device engageable with said securing member disposed at said proximal end of said extension member such that said securing member and said inner wall of said locking device lock said inflation shaft in a fixed position relative to said hub.

5. A method for advancing a telescoping catheter with a variable effective over-the-wire length along a standard length guidewire to the stenosis site, said telescoping catheter having an elongated inflation shaft having open proximal end distal ends and a longitudinal inflation lumen extending therethrough, an extension shaft disposed distal to said inflation shaft, said extension shaft having open proximal and distal ends and a lumen extending therethrough that is in fluid communication with and extends said inflation lumen through the extent of said extension shaft, a guidewire shaft having open proximal end, distal ends and a guidewire lumen extending therethrough, said proximal end of said guidewire shaft being coextensive with said proximal end of said extension shaft, said guidewire shaft extending through said extension shaft lumen and said guidewire shaft distal end extending distal of said extension shaft distal end, an inflatable balloon having a distal end and a proximal end, said balloon proximal end sealingly affixed to said distal end of said extension shaft, said balloon distal end sealingly affixed to said guidewire shaft about said guidewire shaft distal end and the interior of said balloon in fluid communication with said inflation lumen, a first telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said first telescoping tube having an inner diameter sized to permit said extension shaft to be retracted into said first telescoping tube but smaller than said balloon when deflated so that said balloon cannot be retracted into said first telescoping tube, a second telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said second telescoping tube having an inner diameter sized to permit said first telescoping tube to be retracted into said second telescoping tube, a third telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said third telescoping tube having an inner diameter sized to permit said second telescoping tube to be retracted into said third telescoping tube, and said third telescoping tube operatively associated with said first and second telescoping tubes so that the effective over-the-wire length of said balloon dilatation catheter will be reduced as a result of a withdrawal of said inflation shaft from a patient'"'"'s body, a hub disposed at said proximal end of said third telescoping tube, said hub has a central port so that said inflation shaft and said guidewire can be extended through said hub, an extension member integral with said hub, and a locking device engageable with said central port of said hub to lock said guidewire in a fixed position relative to said hub and engageable with said extension member to lock said inflation shaft in a fixed position relative to said hub, said method comprising the steps of:

(a) inserting a guiding catheter into a patient'"'"'s vasculature;

(b) advancing said standard length guidewire, which has a proximal end and a distal end, to across a stenosis site;

(c) maneuvering said first, second and third telescoping tubes to a fully retracted position such that the distal end of said first telescoping tube is located at said distal ends of said second and third tubes;

(d) locking said first, second and third telescoping tubes in said fully retracted position by engaging said locking device with said extension member;

(e) advancing said distal end of said catheter onto said proximal end of said guidewire and forwardly advancing said telescoping catheter until said guidewire proximal end protrudes from said hub;

(f) unlocking said first, second and third telescoping tubes by disengaging said locking device from said extension member; and

(g) advancing said first, second and third telescoping tubes until said balloon member is across said stenosis.

6. A method for advancing a telescoping catheter with a variable effective over-the-wire length along a standard length guidewire to the stenosis site where the catheter is an over-the-wire catheter over the full extent of its length and rapidly exchanging said catheter without making use of an exchange guidewire by reducing the effective over-the-wire length of said catheter, said telescoping catheter having an elongated inflation shaft having open proximal end distal ends and a longitudinal inflation lumen extending therethrough, an extension shaft disposed distal to said inflation shaft, said extension shaft having open proximal and distal ends and a lumen extending therethrough that is in fluid communication with and extends said inflation lumen through the extent of said extension shaft, a guidewire shaft having open proximal end, distal ends and a guidewire lumen extending therethrough, said proximal end of said guidewire shaft being coextensive with said proximal end of said extension shaft, said guidewire shaft extending through said extension shaft lumen and said guidewire shaft distal end extending distal of said extension shaft distal end, an inflatable balloon having a distal end and a proximal end, said balloon proximal end sealingly affixed to said distal end of said extension shaft, said balloon distal end sealingly affixed to said guidewire shaft about said guidewire shaft distal end and the interior of said balloon in fluid communication with said inflation lumen, a first telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said first telescoping tube having an inner diameter sized to permit said extension shaft to be retracted into said first telescoping tube but smaller than said balloon when deflated so that said balloon cannot be retracted into said first telescoping tube, a second telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said second telescoping tube having an inner diameter sized to permit said first telescoping tube to be retracted into said second telescoping tube, a third telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said third telescoping tube having an inner diameter sized to permit said second telescoping tube to be retracted into said third telescoping tube, and said third telescoping tube operatively associated with said first and second telescoping tubes so that the effective over-the-wire length of said balloon dilatation catheter will be reduced as a result of a withdrawal of said inflation shaft from a patient'"'"'s body, a hub disposed at said proximal end of said third telescoping tube, said hub has a central port so that said inflation shaft and said guidewire can be extended through said hub, an extension member integral with said hub, and a locking device engageable with said central port of said hub to lock said guidewire in a fixed position relative to said hub and engageable with said extension member to lock said inflation shaft in a fixed position relative to said hub, said method comprising the steps of:

(a) advancing said standard length guidewire and telescoping catheter in a patient'"'"'s vasculature to a stenosis site;

(b) locking said standard length guidewire in position across said stenosis by engaging said locking device with said central port of said hub;

(c) gripping said inflation shaft and withdrawing said inflation shaft through said hub;

(d) continuing to withdraw said inflation shaft so that said first telescoping tube is fully retracted into said second telescoping tube;

(e) continuing to withdraw said inflation shaft so that said second telescoping tube is fully retracted into said third telescoping tube;

(f) continuing to withdraw said inflation shaft so that said extension shaft is fully retracted into said first telescoping tube;

(g) unlocking said standard length guidewire by disengaging said locking device from said central port of said hub;

(h) locking said first, second and third telescoping tubes in position by engaging said locking device with said extension member;

(i) gripping said guidewire at a position one to two inches proximal of said hub with a first hand;

(j) gripping said inflation shaft with a second hand and rearwardly advancing said inflation shaft to said position of said first hand gripping said guidewire;

(k) repeating steps (i)-(j) until said balloon dilatation catheter distal end is withdrawn from said patient; and

(l) gripping said guidewire at a position distal of said balloon dilatation catheter distal end and pulling said balloon dilatation catheter off said proximal end of said guidewire.

7. A method for advancing a telescoping catheter with a variable effective over-the-wire length along a standard length guidewire to the stenosis site where the catheter is an over-the-wire catheter over the full extent of its length and rapidly exchanging said catheter without making use of an exchange guidewire by reducing the effective over-the-wire length of said catheter, said telescoping catheter having an elongated inflation shaft having open proximal end distal ends and a longitudinal inflation lumen extending therethrough, an extension shaft disposed distal to said inflation shaft, said extension shaft having open proximal and distal ends and a lumen extending therethrough that is in fluid communication with and extends said inflation lumen through the extent of said extension shaft, a guidewire shaft having open proximal end, distal ends and a guidewire lumen extending therethrough, said proximal end of said guidewire shaft being coextensive with said proximal end of said extension shaft, said guidewire shaft extending through said extension shaft lumen and said guidewire shaft distal end extending distal of said extension shaft distal end, an inflatable balloon having a distal end and a proximal end, said balloon proximal end sealingly affixed to said distal end of said extension shaft, said balloon distal end sealingly affixed to said guidewire shaft about said guidewire shaft distal end and the interior of said balloon in fluid communication with said inflation lumen, a first telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said first telescoping tube having an inner diameter sized to permit said extension shaft to be retracted into said first telescoping tube but smaller than said balloon when deflated so that said balloon cannot be retracted into said first telescoping tube, a second telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said second telescoping tube having an inner diameter sized to permit said first telescoping tube to be retracted into said second telescoping tube, a third telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said third telescoping tube having an inner diameter sized to permit said second telescoping tube to be retracted into said third telescoping tube, and said third telescoping tube operatively associated with said first and second telescoping tubes so that the effective over-the-wire length of said balloon dilatation catheter will be reduced as a result of a withdrawal of said inflation shaft from a patient'"'"'s body, a hub disposed at said proximal end of said third telescoping tube, said hub has a central port so that said inflation shaft and said guidewire can be extended through said hub, an extension member integral with said hub, and a locking device engageable with said central port of said hub to lock said guidewire in a fixed position relative to said hub and engageable with said extension member to lock said inflation shaft in a fixed position relative to said hub, said method comprising the steps of:

(a) advancing said standard length guidewire and telescoping catheter in a patient'"'"'s vasculature to a stenosis site;

(b) locking said standard length guidewire in position across said stenosis by engaging said locking device with said central port of said hub;

(c) gripping said inflation shaft and withdrawing said inflation shaft through said hub;

(d) continuing to withdraw said inflation shaft so that said first telescoping tube is fully retracted into said second telescoping tube;

(e) continuing to withdraw said inflation shaft so that said second telescoping tube is fully retracted into said third telescoping tube;

(f) continuing to withdraw said inflation shaft so that said extension shaft is fully retracted into said first telescoping tube;

(g) unlocking said standard length guidewire by disengaging said locking device from said central port of said hub;

(h) locking said first, second and third telescoping tubes in position by engaging said locking device with said extension member;

(i) gripping said guidewire at a position one to two inches proximal of said hub with a first hand;

(j) gripping said inflation shaft with a second hand and rearwardly advancing said inflation shaft to said position of said first hand gripping said guidewire;

(k) repeating steps (i)-(j) until said balloon dilatation catheter distal end is withdrawn from said patient; and

(l) gripping said guidewire at a position distal of said balloon dilatation catheter distal end and pulling said balloon dilatation catheter off said proximal end of said guidewire.

8. A method for advancing a telescoping catheter with a variable effective over-the-wire length along a standard length guidewire to the stenosis site where the catheter is an over-the-wire catheter over the full extent of its length and rapidly exchanging said catheter without making use of an exchange guidewire by reducing the effective over-the-wire length of said catheter, said telescoping catheter having an elongated inflation shaft having open proximal end distal ends and a longitudinal inflation lumen extending therethrough, an extension shaft disposed distal to said inflation shaft, said extension shaft having open proximal and distal ends and a lumen extending therethrough that is in fluid communication with and extends said inflation lumen through the extent of said extension shaft, a guidewire shaft having open proximal end, distal ends and a guidewire lumen extending therethrough, said proximal end of said guidewire shaft being coextensive with said proximal end of said extension shaft, said guidewire shaft extending through said extension shaft lumen and said guidewire shaft distal end extending distal of said extension shaft distal end, an inflatable balloon having a distal end and a proximal end, said balloon proximal end sealingly affixed to said distal end of said extension shaft, said balloon distal end sealingly affixed to said guidewire shaft about said guidewire shaft distal end and the interior of said balloon in fluid communication with said inflation lumen, a first telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said first telescoping tube having an inner diameter sized to permit said extension shaft to be retracted into said first telescoping tube but smaller than said balloon when deflated so that said balloon cannot be retracted into said first telescoping tube, a second telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said second telescoping tube having an inner diameter sized to permit said first telescoping tube to be retracted into said second telescoping tube, a third telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said third telescoping tube having an inner diameter sized to permit said second telescoping tube to be retracted into said third telescoping tube, and said third telescoping tube operatively associated with said first and second telescoping tubes so that the effective over-the-wire length of said balloon dilatation catheter will be reduced as a result of a withdrawal of said inflation shaft from a patient'"'"'s body, a hub disposed at said proximal end of said third telescoping tube, said hub has a central port so that said inflation shaft and said guidewire can be extended through said hub, an extension member integral with said hub, and a locking device engageable with said central port of said hub to lock said guidewire in a fixed position relative to said hub and engageable with said extension member to lock said inflation shaft in a fixed position relative to said hub, said method comprising the steps of:

(a) inserting a guiding catheter into a patient'"'"'s vasculature;

(b) advancing said standard length guidewire, which has a proximal end and a distal end, to across a stenosis site;

(c) maneuvering said first, second and third telescoping tubes to a fully retracted position such that the distal end of said first telescoping tube is located at said distal ends of said second and third tubes;

(d) locking said first, second and third telescoping tubes in said fully retracted position by engaging said locking device with said extension member;

(e) advancing said distal end of said catheter onto said proximal end of said guidewire and forwardly advancing said telescoping catheter until said guidewire proximal end protrudes from said hub;

(f) unlocking said first, second and third telescoping tubes by disengaging said locking device from said extension member; and

(g) advancing said first, second and third telescoping tubes until said balloon member is across said stenosis;

(h) locking said standard length guidewire in position across said stenosis by engaging said locking device with said central port of said hub;

(i) gripping said inflation shaft and withdrawing said inflation shaft through said hub;

(j) continuing to withdraw said inflation shaft so that said first telescoping tube is fully retracted into said second telescoping tube;

(k) continuing to withdraw said inflation shaft so that said second telescoping tube is fully retracted into said third telescoping tube;

(l) continuing to withdraw said inflation shaft so that said extension shaft is fully retracted into said first telescoping tube;

(m) unlocking said standard length guidewire by disengaging said locking device from said central port of said hub;

(n) locking said first, second and third telescoping tubes in position by engaging said locking device with said extension member;

(o) gripping said guidewire at a position one to two inches proximal of said hub with a first hand;

(p) gripping said inflation shaft with a second hand and rearwardly advancing said inflation shaft to said position of said first hand gripping said guidewire;

(q) repeating steps (o)-(p) until said balloon dilatation catheter distal end is withdrawn from said patient; and

(r) gripping said guidewire at a position distal of said balloon dilatation catheter distal end and pulling said balloon dilatation catheter off said proximal end of said guidewire.

9. A method for advancing a telescoping catheter with a variable effective over-the-wire length along a standard length guidewire to the stenosis site, said telescoping catheter having an elongated inflation shaft having open proximal end distal ends and a longitudinal inflation lumen extending therethrough, an extension shaft disposed distal to said inflation shaft, said extension shaft having open proximal and distal ends and a lumen extending therethrough that is in fluid communication with and extends said inflation lumen through the extent of said extension shaft, a guidewire shaft having open proximal end, distal ends and a guidewire lumen extending therethrough, said proximal end of said guidewire shaft being coextensive with said proximal end of said extension shaft, said guidewire shaft extending through said extension shaft lumen and said guidewire shaft distal end extending distal of said extension shaft distal end, an inflatable balloon having a distal end and a proximal end, said balloon proximal end sealingly affixed to said distal end of said extension shaft, said balloon distal end sealingly affixed to said guidewire shaft about said guidewire shaft distal end and the interior of said balloon in fluid communication with said inflation lumen, a first telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said first telescoping tube having an inner diameter sized to permit said extension shaft to be retracted into said first telescoping tube but smaller than said balloon when deflated so that said balloon cannot be retracted into said first telescoping tube, a second telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said second telescoping tube having an inner diameter sized to permit said first telescoping tube to be retracted into said second telescoping tube, a third telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said third telescoping tube having an inner diameter sized to permit said second telescoping tube to be retracted into said third telescoping tube, and said third telescoping tube operatively associated with said first and second telescoping tubes so that the effective over-the-wire length of said balloon dilatation catheter will be reduced as a result of a withdrawal of said inflation shaft from a patient'"'"'s body, a hub disposed at said proximal end of said third telescoping tube, said hub has a central port so that said inflation shaft and said guidewire can be extended through said hub, an extension member integral with and extending proximally from said hub with a securing member disposed at said proximal end of said extension member, and a locking device engageable with said central port of said hub to lock said guidewire in a fixed position relative to said hub and engageable with said securing member disposed at said proximal end of said extension member to lock said inflation shaft in a fixed position relative to said hub, said method comprising the steps of:

(a) inserting a guiding catheter into a patient'"'"'s vasculature;

(b) advancing said standard length guidewire, which has a proximal end and a distal end, to across a stenosis site;

(c) maneuvering said first, second tubes to a telescoping tubes to a fully retracted position such that the distal end of said first telescoping tube is located at said distal ends of said second and third tubes;

(d) locking said first, second and third telescoping tubes in said fully retracted position by engaging said locking device with said securing member disposed at said proximal end of said extension member;

(e) advancing said distal end of said catheter onto said proximal end of said guidewire and forwardly advancing said telescoping catheter until said guidewire proximal end protrudes from said hub;

(f) unlocking said first, second and third telescoping tubes by disengaging said locking device from said securing member; and

(g) advancing said first, second and third telescoping tubes until said balloon member is across said stenosis.

10. A method for advancing a telescoping catheter with a variable effective over-the-wire length along a standard length guidewire to the stenosis site where the catheter is an over-the-wire catheter over the full extent of its length and rapidly exchanging said catheter without making use of an exchange guidewire by reducing the effective over-the-wire length of said catheter, said telescoping catheter having an elongated inflation shaft having open proximal end distal ends and a longitudinal inflation lumen extending therethrough, an extension shaft disposed distal to said inflation shaft, said extension shaft having open proximal and distal ends and a lumen extending therethrough that is in fluid communication with and extends said inflation lumen through the extent of said extension shaft, a guidewire shaft having open proximal end, distal ends and a guidewire lumen extending therethrough, said proximal end of said guidewire shaft being coextensive with said proximal end of said extension shaft, said guidewire shaft extending through said extension shaft lumen and said guidewire shaft distal end extending distal of said extension shaft distal end, an inflatable balloon having a distal end and a proximal end, said balloon proximal end sealingly affixed to said distal end of said extension shaft, said balloon distal end sealingly affixed to said guidewire shaft about said guidewire shaft distal end and the interior of said balloon in fluid communication with said inflation lumen, a first telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said first telescoping tube having an inner diameter sized to permit said extension shaft to be retracted into said first telescoping tube but smaller than said balloon when deflated so that said balloon cannot be retracted into said first telescoping tube, a second telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said second telescoping tube having an inner diameter sized to permit said first telescoping tube to be retracted into said second telescoping tube, a third telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said third telescoping tube having an inner diameter sized to permit said second telescoping tube to be retracted into said third telescoping tube, and said third telescoping tube operatively associated with said first and second telescoping tubes so that the effective over-the-wire length of said balloon dilatation catheter will be reduced as a result of a withdrawal of said inflation shaft from a patient'"'"'s body, a hub disposed at said proximal end of said third telescoping tube, said hub has a central port so that said inflation shaft and said guidewire can be extended through said hub, an extension member integral with and extending proximally from said hub with a securing member disposed at said proximal end of said extension member, and a locking device engageable with said central port of said hub to lock said guidewire in a fixed position relative to said hub and engageable with said securing member disposed at said proximal end of said extension member to lock said inflation shaft in a fixed position relative to said hub, said method comprising the steps of:

(a) advancing said standard length guidewire and telescoping catheter in a patient'"'"'s vasculature to a stenosis site;

(b) locking said standard length guidewire in position across said stenosis by engaging said locking device with said central port of said hub;

(c) gripping said inflation shaft and withdrawing said inflation shaft through said hub;

(d) continuing to withdraw said inflation shaft so that said first telescoping tube is fully retracted into said second telescoping tube;

(e) continuing to withdraw said inflation shaft so that said second telescoping tube is fully retracted into said third telescoping tube;

(f) continuing to withdraw said inflation shaft so that said extension shaft is fully retracted into said first telescoping tube;

(g) unlocking said standard length guidewire by disengaging said locking device from said central port of said hub;

(h) locking said first, second and third telescoping tubes in position by engaging said locking device with said securing member disposed at said proximal end of said extension member;

(i) gripping said guidewire at a position one to two inches proximal of said hub with a first hand;

(j) gripping said inflation shaft with a second hand and rearwardly advancing said inflation shaft to said position of said first hand gripping said guidewire;

(k) repeating steps (i)-(j) until said balloon dilatation catheter distal end is withdrawn from said patient; and

(l) gripping said guidewire at a position distal of said balloon dilatation catheter distal end and pulling said balloon dilatation catheter off said proximal end of said guidewire.

11. A method for advancing a telescoping catheter with a variable effective over-the-wire length along a standard length guidewire to the stenosis site where the catheter is an over-the-wire catheter over the full extent of its length and rapidly exchanging said catheter without making use of an exchange guidewire by reducing the effective over-the-wire length of said catheter, said telescoping catheter having an elongated inflation shaft having open proximal end distal ends and a longitudinal inflation lumen extending therethrough, an extension shaft disposed distal to said inflation shaft, said extension shaft having open proximal and distal ends and a lumen extending therethrough that is in fluid communication with and extends said inflation lumen through the extent of said extension shaft, a guidewire shaft having open proximal end, distal ends and a guidewire lumen extending therethrough, said proximal end of said guidewire shaft being coextensive with said proximal end of said extension shaft, said guidewire shaft extending through said extension shaft lumen and said guidewire shaft distal end extending distal of said extension shaft distal end, an inflatable balloon having a distal end and a proximal end, said balloon proximal end sealingly affixed to said distal end of said extension shaft, said balloon distal end sealingly affixed to said guidewire shaft about said guidewire shaft distal end and the interior of said balloon in fluid communication with said inflation lumen, a first telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said first telescoping tube having an inner diameter sized to permit said extension shaft to be retracted into said first telescoping tube but smaller than said balloon when deflated so that said balloon cannot be retracted into said first telescoping tube, a second telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said second telescoping tube having an inner diameter sized to permit said first telescoping tube to be retracted into said second telescoping tube, a third telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said third telescoping tube having an inner diameter sized to permit said second telescoping tube to be retracted into said third telescoping tube, and said third telescoping tube operatively associated with said first and second telescoping tubes so that the effective over-the-wire length of said balloon dilatation catheter will be reduced as a result of a withdrawal of said inflation shaft from a patient'"'"'s body, a hub disposed at said proximal end of said third telescoping tube, said hub has a central port so that said inflation shaft and said guidewire can be extended through said hub, an extension member integral with and extending proximally from said hub with a securing member disposed at said proximal end of said extension member, and a locking device engageable with said central port of said hub to lock said guidewire in a fixed position relative to said hub and engageable with said securing member disposed at said proximal end of said extension member to lock said inflation shaft in a fixed position relative to said hub, said method comprising the steps of:

(a) advancing said standard length guidewire and telescoping catheter in a patient'"'"'s vasculature to a stenosis site;

(b) locking said standard length guidewire in position across said stenosis by engaging said locking device with said central port of said hub;

(c) gripping said inflation shaft and withdrawing said inflation shaft through said hub;

(d) continuing to withdraw said inflation shaft so that said first telescoping tube is fully retracted into said second telescoping tube;

(e) continuing to withdraw said inflation shaft so that said second telescoping tube is fully retracted into said third telescoping tube;

(f) continuing to withdraw said inflation shaft so that said extension shaft is fully retracted into said first telescoping tube;

(g) unlocking said standard length guidewire by disengaging said locking device from said central port of said hub;

(h) locking said first, second and third telescoping tubes in position by engaging said locking device with said securing member disposed at said proximal end of said extension member;

(i) gripping said guidewire at a position one to two inches proximal of said hub with a first hand;

(j) gripping said inflation shaft with a second hand and rearwardly advancing said inflation shaft to said position of said first hand gripping said guidewire;

(k) repeating steps (i)-(j) until said balloon dilatation catheter distal end is withdrawn from said patient; and

(l) gripping said guidewire at a position distal of said balloon dilatation catheter distal end and pulling said balloon dilatation catheter off said proximal end of said guidewire.

12. A method for advancing a telescoping catheter with a variable effective over-the-wire length along a standard length guidewire to the stenosis site where the catheter is an over-the-wire catheter over the full extent of its length and rapidly exchanging said catheter without making use of an exchange guidewire by reducing the effective over-the-wire length of said catheter, said telescoping catheter having an elongated inflation shaft having open proximal end distal ends and a longitudinal inflation lumen extending therethrough, an extension shaft disposed distal to said inflation shaft, said extension shaft having open proximal and distal ends and a lumen extending therethrough that is in fluid communication with and extends said inflation lumen through the extent of said extension shaft, a guidewire shaft having open proximal end, distal ends and a guidewire lumen extending therethrough, said proximal end of said guidewire shaft being coextensive with said proximal end of said extension shaft, said guidewire shaft extending through said extension shaft lumen and said guidewire shaft distal end extending distal of said extension shaft distal end, an inflatable balloon having a distal end and a proximal end, said balloon proximal end sealingly affixed to said distal end of said extension shaft, said balloon distal end sealingly affixed to said guidewire shaft about said guidewire shaft distal end and the interior of said balloon in fluid communication with said inflation lumen, a first telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said first telescoping tube having an inner diameter sized to permit said extension shaft to be retracted into said first telescoping tube but smaller than said balloon when deflated so that said balloon cannot be retracted into said first telescoping tube, a second telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said second telescoping tube having an inner diameter sized to permit said first telescoping tube to be retracted into said second telescoping tube, a third telescoping tube slidably mounted on said inflation shaft and said extension shaft so as to be extendable over at least a portion of a guidewire extending proximally from said guidewire lumen, said third telescoping tube having an inner diameter sized to permit said second telescoping tube to be retracted into said third telescoping tube, and said third telescoping tube operatively associated with said first and second telescoping tubes so that the effective over-the-wire length of said balloon dilatation catheter will be reduced as a result of a withdrawal of said inflation shaft from a patient'"'"'s body, a hub disposed at said proximal end of said third telescoping tube, said hub has a central port so that said inflation shaft and said guidewire can be extended through said hub, an extension member integral with and extending proximally from said hub with a securing member disposed at said proximal end of said extension member, and a locking device engageable with said central port of said hub to lock said guidewire in a fixed position relative to said hub and engageable with said securing member disposed at said proximal end of said extension member to lock said inflation shaft in a fixed position relative to said hub, said method comprising the steps of:

(a) inserting a guiding catheter into a patient'"'"'s vasculature;

(b) advancing said standard length guidewire, which has a proximal end and a distal end, to across a stenosis site;

(c) maneuvering said first, second and third telescoping tubes to a fully retracted position such that the distal end of said first telescoping tube is located at said distal ends of said second and third tubes;

(d) locking said first, second and third telescoping tubes in said fully retracted position by engaging said locking device with said securing member disposed at said proximal end of said extension member;

(e) advancing said distal end of said catheter onto said proximal end of said guidewire and forwardly advancing said telescoping catheter until said guidewire proximal end protrudes from said hub;

(f) unlocking said first, second and third telescoping tubes by disengaging said locking device from said securing member; and

(g) advancing said first, second and third telescoping tubes until said balloon member is across said stenosis;

(h) locking said standard length guidewire in position across said stenosis by engaging said locking device with said central port of said hub;

(i) gripping said inflation shaft and withdrawing said inflation shaft through said hub;

(j) continuing to withdraw said inflation shaft so that said first telescoping tube is fully retracted into said second telescoping tube;

(k) continuing to withdraw said inflation shaft so that said second telescoping tube is fully retracted into said third telescoping tube;

(l) continuing to withdraw said inflation shaft so that said extension shaft is fully retracted into said first telescoping tube;

(m) unlocking said standard length guidewire by disengaging said locking device from said central port of said hub;

(n) locking said first, second and third telescoping tubes in position by engaging said locking device with said securing member disposed at said proximal end of said extension member;

(o) gripping said guidewire at a position one to two inches proximal of said hub with a first hand;

(p) gripping said inflation shaft with a second hand and rearwardly advancing said inflation shaft to said position of said first hand gripping said guidewire;

(q) repeating steps (o)-(p) until said balloon dilatation catheter distal end is withdrawn from said patient; and

(r) gripping said guidewire at a position distal of said balloon dilatation catheter distal end and pulling said balloon dilatation catheter off said proximal end of said guidewire.

13. A locking device in combination with a catheter and a guidewire which is slidable with respect to said catheter, said catheter includes a catheter body having a distal end and a proximal end, an elongated slidable portion which is slidable with respect to said catheter body, and a hub disposed at the proximal end of said catheter body, said locking device comprising:

a first locking surface engageable with said hub for locking said guidewire in a fixed position relative to said hub while said elongated slidable portion remains slidable with respect to said catheter body; and

a second locking surface engageable with said hub for locking said elongated slidable portion in a fixed position relative to said hub while said guidewire remains slidable with respect to said catheter.

14. A locking apparatus, in combination with a catheter and a guidewire which is slidable with respect to said catheter, said catheter includes a catheter body having a distal end and a proximal end, an elongated slidable portion which is slidable with respect to said catheter body, and a hub disposed at said proximal end of said catheter body, said hub having an inner wall defining a central port through which extend said guidewire and elongated slidable portion, said locking apparatus comprising:

an extension member integral with said hub; and

a locking device having a distal end, a proximal end, an outer first locking surface and an inner second locking surface defining a locking lumen extending between said distal and proximal ends, said locking device slidably mounted on said elongated slidable portion so that said elongated slidable portion extends through said locking lumen, said locking device engageable with said central port of said hub such that said first locking surface engages with said inner wall of said hub to lock said guidewire in a fixed position relative to said hub while said elongated slidable portion remains slidable with respect to said catheter body, and said locking device engageable with said hub such that said second locking surface engages with said extension member to lock said elongated slidable portion in a fixed position relative to said hub while said guidewire remains slidable with respect to said catheter.

15. The locking apparatus defined in claim 14 wherein said extension member extends proximally from said hub.

16. The locking apparatus defined in claim 15 wherein said extension member supports said locking device when said locking device is engaged with said central port of said hub.

17. A locking device in combination with a catheter and a guidewire which is slidable with respect to said catheter, said catheter includes a catheter body having a distal end and a proximal end, an elongated portion, and a hub disposed at the proximal end of said catheter body, said locking device comprising:

a locking surface slidably engageable with said hub for locking said guidewire in a fixed position relative to said hub; and

sliding means for slidingly mounting said locking surface on said elongated portion so that said locking surface is slidable with respect to said hub.

18. A locking device in combination with a catheter and a guidewire which is slidable with respect to said catheter, said catheter includes a catheter body having a distal end and a proximal end, an elongated slidable portion which is slidable with respect to said catheter body, and a hub disposed at the proximal end of said catheter body, said hub having an inner wall defining a central port through which extend said guidewire and elongated slidable portion, said locking device comprising:

a locking surface slidably engageable with said inner wall of said hub to lock said guidewire in a fixed position relative to said hub while said elongated slidable portion remains slidable with respect to said catheter body; and

sliding means for slidingly mounting said locking surface on said elongated slidable portion so that said locking surface is slidable with respect to said hub.

19. A locking device in combination with a telescoping catheter and a guidewire which is slidable with respect to said telescoping catheter, said telescoping catheter includes an elongated inflation shaft, a plurality of telescoping tubes slidably mounted on said inflation shaft, and a hub disposed at the proximal end of one of said telescoping tubes and having an inner wall defining a central port through which extend said inflation shaft and said guidewire, said locking device comprising:

a locking surface slidably engageable with said inner wall of said hub to lock said guidewire in a fixed position relative to said hub; and

sliding means for slidingly mounting said locking surface on said inflation shaft so that said locking surface is slidable with respect to said hub.