Medical systems, devices and methods for coupling wire guides

Medical systems, devices and methods are provided for coupling a wire guide to a previously introduced wire guide in intracorporeal procedures, and generally include a supplemental wire guide and a tracking element. The tracking element defines a first passageway and a second passageway. The first passageway is sized to receive the previously introduced wire guide and the second passageway is sized to receive the supplemental wire guide. The supplemental wire guide is attached to the tracking element in a coupled configuration and detached from the tracking element in a decoupled configuration for independent translation of the supplemental wire guide.

FIELD OF THE INVENTION

This invention relates generally to medical systems, devices and methods for using wire guides in intracorporeal procedures, and more particularly relates to coupling a wire guide to a previously introduced wire guide for assistance during interventional procedures in vessels with proximal tortuosity, or as a more substantial wire guide for angioplasty procedures, stenting procedures, and other device placement procedures and their related devices.

BACKGROUND OF THE INVENTION

Proximal tortuosity of the vasculature is problematic for all medical catheter devices such as atherectomy devices, angioplasty devices, stent delivery devices, and filter delivery devices. Wire guides are therefore typically used to navigate the vasculature of a patient during percutaneous interventional procedures. Once the wire guide has been introduced, it may then be used to introduce one or more medical catheter devices. Thus, most wire guides are typically 0.014 inches in diameter and have a lubricious coating to enhance wire guide introduction movement. Conventional 0.014 inch floppy wire guides must have sufficient flexibility and torque control for navigation through tortuous vessels. At the same time, the wire guide must have a certain amount of rigidity to pass through lesions, straighten extremely tortuous vessels, and support medical catheter devices that are introduced over the wire guide.

Accordingly, wire guides are subjected to potentially conflicting requirements. Conventional 0.014 inch floppy wire guides are usually sufficient for navigation of moderately tortuous vessels. However, in some situations the wire guide tip may prolapse away from the site to which it is guiding the device. For example, balloon angioplasty in vessels with proximal tortuosity has been associated with a higher incidence of acute complications and procedural failure due to the inability to cross lesions with a conventional floppy wire guide, and due to the inability of the wire guide to provide adequate support to the balloon catheter. Heavy-duty wire guides, on the other hand, are generally not well suited as primary wire guides because of their stiffness and potential for causing injury to the vessel during introduction.

It may therefore be desirable to use conventional floppy wire guides for navigation of tortuous vessels, and then enhance the conventional wire guide with a supplemental wire guide. The supplemental wire guide will straighten out the vessel curves and ease further wire guide movement. Additionally, the supplemental wire guide provides greater support and enhances the tracking of balloons, stents, stent delivery devices, atherectomy devices, and other medical catheter devices as compared to a conventional floppy wire guide. This technique is commonly referred to as the “Buddy Wire” technique, details of which are disclosed in U.S. patent application Ser. No. 11/081,146, filed Mar. 16, 2005, and incorporated herein by reference.

However, the navigation of the supplemental wire guide parallel to the first wire guide is an exacting and time consuming process in which additional difficulties are encountered. For example, the second wire guide can cork screw or coil around the first wire guide, which may result in immobilization or unintended movement of the first wire guide, which in turn may require the retraction and re-feeding of the supplemental wire guide and/or the primary wire guide. Moreover, if retraction of the supplemental wire guide is necessary, either of the wire guides may become contaminated and the entire process may need to be restarted with sterile components. The time consumed by this process can be critical to the success of the procedure. Additionally, when traversing through the heart of a patient, and particularly the ostium, the larger open space of the heart makes identical placement of the supplemental wire guide somewhat difficult.

BRIEF SUMMARY OF THE INVENTION

The present invention provides medical systems, devices and methods for coupling a wire guide to a previously introduced wire guide in intracorporeal procedures, permitting easy and reliable placement of the supplemental wire guide, as well as allowing decoupling for independent translation of the supplemental wire guide.

One embodiment of a medical system, constructed in accordance with the teachings of the present invention, generally includes a supplemental wire guide and a tracking element. The supplemental wire guide has a main body and a distal end. The tracking element has a first portion defining a first passageway and a second portion defining a second passageway. The first passageway is sized to receive the previously introduced wire guide and permit translation of the tracking element relative to the previously introduced wire guide. The second passageway is sized to receive the supplemental wire guide. The medical system is operable between a coupled configuration and a decoupled configuration. The supplemental wire guide is attached to the tracking element in the coupled configuration such that translation of the supplemental wire guide causes translation of the tracking element. The supplemental wire guide is detached from the tracking element in the decoupled configuration for independent translation of the supplemental wire guide.

According to more detailed aspects, the tracking element is attached to a distal end of the supplemental wire guide in the coupled configuration. In one construction, the distal end of the supplemental wire guide includes a wound outer coil, and the second portion of the tracking element defines internal threads over at least a portion of the second passageway. The internal threads are sized and structured to matingly receive the wound outer coil of the distal end of the supplemental wire guide. A portion of the distal ends of the supplemental wire guide or the previously introduced wire guide may have an outer diameter greater than the diameter of the corresponding passageway to prevent translation of the tracking element beyond the distal end. The medical system may also include a tether connected to the tracking element for retraction thereof. In another construction, the main body of the supplemental wire guide may provide clearance with the second passageway to permit translation of a medical device over the supplemental wire guide and to the second passageway of the tracking element.

A method for coupling to a previously introduced wire guide during intracorporeal procedures is also provided in accordance with the teachings of the present invention. A medical system, such as the system described above, is provided in the coupled configuration. The previously introduced wire guide is positioned within the first passageway of the tracking element. The supplemental wire guide and tracking element are together translated distally along the previously introduced wire guide. The supplemental wire guide is decoupled from the tracking element, and is translated independently of the previously introduced wire guide. Depending on the construction of the medical system and device, the supplemental wire guide may remain within the second passageway of the tracking element, or may be outside of the second passageway. When a tether is employed, the method may also include retraction of the tether proximally to translate the tracking element over one or both of the two wire guides, either in the coupled configuration or decoupled configuration.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to the figures,FIGS. 1-5depict a medical system20having a medical device30for coupling to a previously introduced wire guide22during intacorporeal procedures, in accordance with the teachings of the present invention. The previously introduced wire guide22generally includes a main body24having a distal end26with an end cap28. The medical system20generally includes a supplemental wire guide32and a tracking element34. The tracking element34is utilized to couple the supplemental wire guide32to the previously introduced wire guide22for simple and reliable introduction of the supplemental wire guide32along the path traversed by the previously introduced wire guide22. At the same time, the medical system20and medical device30allow decoupling of the supplemental wire guide32so that it may be independently translated, thereby enabling a second path to be taken by the supplemental wire guide32.

The supplemental wire guide32generally includes a main body36and a distal end38. As best seen in the cross-sectional view ofFIG. 2, the distal end38of the supplemental wire guide32is defined by a tapered distal end portion36dof the main body36, around which an outer wire40has been helically wound. As is known in the art, the tapered distal end portion36dand outer wire40are joined through soldering or other mechanical means, including an end cap42formed at the distal tip of the supplemental wire guide32. It will be recognized that the construction of the supplemental wire guide32, as well as the previously introduced wire guide22, may take numerous forms as many types of wire guides are known in the art, including solid wire, tubular wires, coiled wires and combinations thereof. For example, U.S. Pat. No. 5,243,996 discloses an exemplary solid wire mandrel having a coiled tip section, the disclosure of which is hereby incorporated by reference in its entirety.

The tracking element34generally includes a first portion44and a second portion46. The first portion44links the tracking element34to the previously introduced wire guide22, while the second portion46links the tracking element34to the supplemental wire guide32. As best seen inFIGS. 4 and 5, the first portion44of the tracking element34defines a first passageway54, while the second portion46defines a second passageway56. The first and second passageways54,56have been shown as generally cylindrical, but they can take any cross-sectional shape as will be recognized by those skilled in the art. The second passageway56includes internal threads58extending along at least a portion of the length of the second passageway56. The first passageway54is sized relative to an outer diameter of the previously introduced wire guide22, and in particular its main body24, to permit relative translation such that the tracking element34may slide along the previously introduced wire guide22. Similarly, the second passageway56is sized relative to the supplemental wire guide32, and in particular its main body36, to permit relative translation such that the supplemental wire guide32may be at least partially slid through the second portion46of the tracking element34.

A third portion48of the tracking element34connects the first and second portions44,46. An optional tether50such as a suture, cable, or wire is connected to the third portion48, although it may be connected to any portion of the tracking element34. The third portion48of the tracking element34preferably forms a hinge permitting relative movement between the first portion44and second portion46of the tracking element34. That is, the third portion48may provide some flexure and is preferably formed as a living hinge. The ability for relative movement between the first and second portions44,46can facilitate introduction and translation of the supplemental wire guide32along the previously introduced wire guide22. The tracking element34preferably includes radiused or buffed outer edges to improve the atraumatic nature and facilitate translation of the tracking element34along the previously introduced wire guide22. The tracking element34may be formed of various materials including metals such as stainless steel or platinum, alloys including super elastic alloys such a nitinol, various plastics such as polyvinylchloride, polyimide, polycarbonate, polyetherkeytone, or composites, and similar materials is known in the art.

The medical system20is generally operable between a coupled configuration, as shown inFIG. 1, and a decoupled configuration, as is shown inFIG. 3. In the coupled configuration, the supplemental wire guide32is longitudinally attached to the tracking element34such that translation of the supplemental wire guide32causes translation of the tracking element34. In the decoupled configuration, the supplemental wire guide32is longitudinally detached from the tracking element34for independent translation of the supplemental wire guide32. More specifically, and as best seen inFIGS. 2 and 4, the internal threads58of the second portion46matingly receive the helically wound outer wire40in the coupled configuration. As such, the distal end38of the supplemental wire guide32is fixedly attached to the tracking element34for translation of the medical system20along the previously introduced wire guide22. In the decoupled configuration, the supplemental wire guide32has been rotated or torqued such that the outer wire40no longer mates with the internal threads58, whereby the supplemental wire guide32is detached from the tracking element34. In this decoupled configuration, the main body36of the supplemental wire guide32may be freely translated through the second passageway56, as shown inFIG. 3. In this manner, the supplemental wire guide32may be independently translated, for example, when it is desirable to take a second path during a medical procedure.

Depending upon the medical procedures to be performed, it may be desirable to prevent the tracking element34from passing beyond the distal end26of the previously introduced wire guide22, and likewise beyond the distal end38of the supplemental wire guide32. Accordingly, at least a portion of the distal ends26,38can be sized larger than the first and second passageways54,56of the tracking element34. For example, the end cap28of the previously introduced wire guide22has been shown having an outer diameter greater than the first passageway54, thereby preventing the tracking element34from passing beyond the distal end26of the supplemental wire guide22. Likewise, the end cap42of the supplemental wire guide32has been shown as being larger than the second passageway56in the tracking element34. On the other hand, either or both of the distal ends26,38of the previously introduced wire guide22and supplemental wire guide32may alternatively be sized such that they can pass through the first and second passageways54,56in the tracking element34.

As previously mentioned, the tether50can be employed and connected to the third portion48of the tracking element34. Proximal retraction of the tether50permits the tracking element34to be withdrawn proximally once the supplemental wire guide32has assumed the decoupled configuration. Similarly, it may be desirable to completely remove the supplemental wire guide32from within the tracking element34. For example, another embodiment of a medical system120and device130is shown inFIGS. 6-8and includes a supplemental wire guide132having a main body136with a distal end138formed by an outer coiled wire140and an end cap142. The tracking element134includes a first portion144and a second portion146connected by a third portion148. The first portion144defines a first passageway154while the second portion146defines a second passageway156. In this embodiment, internal threads158within the second portion146extend along the entire length of the second passageway156. The end cap142of the supplemental wire guide132has an outer diameter sized less than or equal to an outer diameter defined by the outer wound wire140and the second passageway156. In this manner, the supplemental wire guide132may be rotated to withdraw the supplemental wire guide132from the second passageway158. In particular, the second passageway156includes a proximal port156pand a distal port156d, and the distal end138of the supplemental wire guide132may be retracted through the proximal port156psuch that the supplemental wire guide132does not extend through the second passageway156. In this manner, and as shown inFIG. 8, the supplemental wire guide132may be independently translated, while the tracking element134remains linked to the previously introduced wire guide122(via the main body124extending through the first portion144of the tracking element134).

It will also be recognized that in the embodiments ofFIGS. 6-8, a catheter-based device such as a dilation balloon or the like may be passed over the supplemental wire guide132, and when in the decoupled configuration, may be employed at a secondary location. Similarly, another embodiment of a medical system220and device230is shown inFIG. 9and depicts how the passageway in the second portion of the tracking element can be sized relative to the supplemental wire guide to permit passage of catheter based devices therethrough. In particular, the tracking element234includes first, second and third portions244,246,248and defines a first passageway254and a second passageway256. Here, the coupling wire232includes a main body236that does not taper at its distal end238. An outer wire240is coiled around the distal end238and joins the main body236at a distal end cap242. The main body236of the supplemental wire guide232has an outer diameter less than a diameter of the second passageway256to provide a clearance C therebetween. Preferably, the clearance C is sized to permit translation of a catheter-based medical device over the supplemental wire guide232and through the second passageway256of the second portion246of the tracking element34.

A method employing these medical systems and medical devices is also provided in accordance with the teachings of the present invention. According to the method, a medical system, as such the medical systems20,120,220described above, is provided in the coupled configuration. Using the medical system20as an example, the previously introduced wire guide22is positioned within the first passageway54of the tracking element34such as by passing the tracking element34over the proximal end of the previously introduced wire guide22. The supplemental wire guide32and tracking element34are together translated distally along the previously introduced wire guide22. The supplemental wire32is decoupled from the tracking element34, such as by rotating the proximal end (not shown) of the supplemental wire guide32to unscrew the coiled outer wire40from the internal threads58of the second passageway56. The supplemental wire guide32is then translated independently of the previously introduced wire guide22. The main body36of the supplemental wire guide32remains within the second passageway56, although the main body236in the medical device220may be outside of the second passageway256, as previously discussed. Likewise, when the medical device30includes a tether50connected to the third portion58of the tracking element34, the tether50may be retracted to proximally translate the tracking element34over one or both of the two wire guides22,32, either in the coupled configuration or the decoupled configuration.

It will also be recognized by those skilled in the art that other mating structures may be formed to permit selective coupling and decoupling of the distal end of the supplemental wire guide and the tracking element. For example, flexible tabs and detents may be employed (such as the wire guide including outwardly extending tabs and the second passageway including corresponding detents) or other frictional fits or mechanical arrangements that may be overcome by either axial movement or rotational movement of the supplemental wire guide. Further, many different devices may be employed over either of the wire guides, including catheter devices, angioplasty devices, stenting devices, embolic protection devices, filtering devices, biopsy devices, cooling/aspiration devices and many other medical devices which may be tracked over a wire guide. Finally, while wire guides are often used in percutaneous interventional procedures, it will be recognized by those skilled in the art that the wire guide20of the present invention may also be employed non-percutaneously, such as in endoscopic or other intracorporeal procedures.