WO2008051898A2

WO2008051898A2 - Devices and methods for unwrapping or preventing the wrapping of elongated medical devices

Info

Publication number: WO2008051898A2
Application number: PCT/US2007/082068
Authority: WO
Inventors: Randall J. Beyeris; Fernando Di Caprio; Brady J. Hatcher
Original assignee: Via Biomedical, Inc.
Priority date: 2006-10-22
Filing date: 2007-10-22
Publication date: 2008-05-02
Also published as: WO2008051898B1; WO2008051898A3

Abstract

Devices and methods for unwrapping (or otherwise overcoming the entanglement of), or preventing the wrapping of, guidewires and similar elongated medical devices deployed (or about to be deployed) in vessels of a patient. Embodiments have sufficient flexibility to be deployed by distally threading at least one lumen over a guidewire, and sufficient torqueability to enable axial rotation of the combination to unwrap the entangled devices or prevent further entanglement as additional guidewires are advanced through other lumens.

Description

DEVICES AND METHODS FOR UNWRAPPING OR PREVENTING THE WRAPPING OF ELONGATED MEDICAL DEVICES

TECHNICAL FIELD

This application involves devices and methods for unwrapping (or otherwise overcoming the entanglement of) guidewires (or similar objects) in the vessels of a patient, including the prevention of such wrapping or entanglement in the first place.

BACKGROUND

Many medical procedures involve the use of one or more guidewires advanced through successive or adjacent portions of vessels of a patient, such as those of the coronary, neurological, or other vasculatures; or those of similar vessel-like systems (e.g., the lymphatic, urinary, reproductive, respiratory or digestive systems).

In some cases, it is clinically necessary to use multiple guidewires or to add or replace a guidewire with another having a different size, texture, stiffness, radiopacity or other feature desired by the attending physician. Even if this is not the case, when a second or subsequent guidewire is inserted, it may become entangled with the first inserted guidewire, in the sense that portions of any of the guidewires may wrap partially or totally around each other at one or more locations between the proximal and distal ends of the guidewires. This is because the guidewires are typically relatively small in diameter compared to the vessel, and the vessel is also typically filled with fluid (e.g., blood). Thus, the guidewires are free to move side-to-side within the vessel as they are advanced down the length of the vessel. In addition, the physician may also rotate (or,

"torque") the guidewire while advancing it. Also, some commercially available guidewires have pre-formed tips (e.g., preformed bent tips) which increase the opportunity for entanglement. The problem is known as "wire wrap" or "wrapped wires" or similar terms.

The attending physician typically visualizes only the distal end of the guidewires with fluoroscopy or some other type of real time imaging, because those are usually the only portions of the guidewires bearing radiopaque markers enabling visualization. Regardless of guidewire radiopacity, the entanglement location(s) may be anywhere along the length of the vessel, and thus typically are difficult to see due to imaging limitations. While skilled physicians may believe that some degree of entanglement has occurred, they do not generally know the exact entanglement location(s), which guidewire is wrapped around which, the direction of the wrap, or the degree of the problem.

It may be very dangerous to "wiggle" or rotate the proximal ends of the guidewires, once they are placed in a vessel, in an attempt to disentangle them. Rotating one or more of the guidewires at the proximal end may worsen the entanglement. The physician may decide to continue with the procedure in the hope that additional devices proceeding down the guidewire(s) may "push through" the entanglement, even though attempting to force a therapeutic device over entangled wires may cause injury or trauma to the vessels, or damage to the device. Thus, it may not be advisable or even possible to proceed unless a guidewire is removed and re-inserted or replaced.

Perhaps a greater problem occurs when the attending physician is not aware of the severity of the problem until after all guidewires are placed, and it becomes apparent that a more expensive therapeutic catheter (such as a balloon catheter or a stent delivery system) cannot be advanced over the guidewire(s) past the location of entanglement. This can require removal of the therapeutic catheter, and perhaps also one or more of the guidewires, well into the progress of the medical procedure.

Even if the attending physician is able to advance the therapeutic catheter through any entanglements, the wrapped guidewires may scrape against the catheter. If the catheter carries a stent (or similar feature) that may or may not have been coated or otherwise treated with a therapeutic material on its surface, the stent could be dislodged or the therapeutic material borne by the stent may be damaged by the scraping against the guidewires. Stents, particularly coated stents, are very expensive, and thus even very small risks of dislodgement or displaced coating create undesirable results with unsuccessful clinical or financial outcomes. Furthermore, the kinetics of the controlled-release profile of the therapeutic material may also be adversely affected by any damage caused by scraping against the entangled guidewires even if the procedure is otherwise successful.

In the commonly performed percutaneous transluminal coronary angioplasty (PTCA) procedure (which is very often followed by placement of one or more uncoated or coated stents), it is believed that entanglement can occur in a significant proportion of procedures in which multiple guidewires are used, and there may be multiple entanglements in each such procedure. Entanglement complicates (and therefore lengthens the duration) of procedures, as well as potentially increases the risk of complications.

SUMMARY

One aspect of this application involves an apparatus for unwrapping guidewires advanced into a vessel. A main body, having proximal and distal ends, is combined with at least two lumens that are supported by the main body. Each lumen has a proximal opening, and each lumen extends distally at least as far as the distal end of the main body. The apparatus as a whole has sufficient flexibility to be advanced over the guidewires by passing each guidewire though one of the lumens .

Another aspect of this application is very similar to the first aspect, but involves prevention of the entanglement of guidewires from occurring. This aspect involves application of the apparatus just described to a first guidewire that has previously been advanced into the body. A second guidewire may be subsequently advanced through its respective lumen. The second guidewire may be "pre-loaded," i.e., already partially deployed within the apparatus, prior to advancing the apparatus over the first guidewire. Alternatively, the second guidewire may be introduced into the apparatus after the apparatus is advanced over the first guidewire.

Other aspects involve methods for unwrapping guidewires, or for preventing the entanglement of guidewires. These methods employ an apparatus that comprises the combination of a main body having a distal end, and at least two lumens. At least one lumen of the apparatus is advanced over at least one guidewire previously advanced in the vessel; this may be the only guidewire so advanced, or it may be one of a plurality of guidewires. The apparatus is distally advanced through the vessel over the guidewire(s). If the apparatus has been distally advanced over two guidewires, the main body is not twisted as necessary to unwrap the guidewires. If the apparatus has been distally advanced over only a first guidewire, a second guidewire may then be advanced through the apparatus, with the apparatus during deployment to prevent entanglement. The second guidewire may be pre-loaded as described above. Once all guidewires are deployed without entanglement, the apparatus is proximally removed. Any of the aspects described here may be practiced with embodiments that are adapted for rapid exchange procedures, or for over-the-wire procedures. Furthermore, in any of the aspects, references to two lumens should be understood as including a structure in which a single passage has two distinct portions, into each of which only a single guidewire may fit, but the two portions are nonetheless partially joined together. Thus, each portion operates like a lumen as described above.

DESCRIPTION OF THE FIGURES

The accompanying drawings schematically illustrate particular embodiments, and are not intended to limit the scope of the invention.

Figure 1 is schematic top view of one embodiment.

Figures IA and IB are magnified views of the proximal and distal ends, respectively, of the embodiment of Figure 1, taken along the lines A-A and B-B, respectively.

Figure 2 is a schematic top view of another embodiment.

Figures 3-8 are expanded views of portions of an embodiment generally corresponding to the embodiments of Figures 1 and 2.

Figures 9-12 are expanded views of portions of a preferred embodiment generally corresponding to the embodiment of Figure 2.

Figure 13 is a perspective view of a preferred embodiment of an optional handle for use with various embodiments.

Figure 14 is schematic top view of an embodiment.

Figures 14A and 14B are magnified views of the proximal and distal ends, respectively, of the embodiment of Figure 14, taken along the lines A-A and B-B, respectively.

Figure 15 is a schematic top view of another embodiment.

Figure 16 is a schematic perspective view of another embodiment.

Figure 17 is a magnified cross-sectional view of the proximal or distal end of an alternative embodiment. Figure 18 is a magnified cross-sectional view of the proximal or distal end of an alternative embodiment.

DETAILED DESCRIPTION

The following discussion accompanies the drawings, which schematically illustrate a particular embodiment, and are not intended to limit the scope of the invention. Thus, any reading of this discussion as limiting the scope of the invention is contrary to the intent of the inventors, who intend this discussion to describe and enable the full scope of their invention as limited only by the language of the accompanying claims.

Figure 1 is a top view of a schematic representation of an embodiment adapted for unwrapping guide wires (not shown) previously advanced within a vessel of the body (also not shown). Figures IA and IB are cross-sections of the proximal and distal ends, respectively, of the embodiment, as indicated at A-A and B-B.

Figure 2 is a schematic illustration similar to Figure 1, except that apparatus 200 is adapted for "rapid exchange" ("RX") procedures, as will be described in more detail below. Otherwise, the components of apparatus 200 are analogous to those of apparatus 100 and therefore the discussion of apparatus 100 applies to apparatus 200 except as specifically described below.

Apparatus 100 generally comprises a main body 11, whose cross section is preferably round as illustrated, but in general could be oval or some other closed shape. In this embodiment, two lumen extensions 12 and 13 each extend from the distal portion of main body 11. However, the use of lumen extensions is entirely optional. In any event, main body 11 and each respective lumen extension 12 and 13 define within themselves lumens 14 and 15, respectively. Each of lumens 14 and 15 extends continuously throughout the length of main body 11 and its respective lumen extension 12 or 13 throughout the entire length of apparatus 100. Each lumen extension 12 and 13 has a respective distal tip such as tip 21 illustrated on lumen extension 12. In the vicinity of the lumen extension tip, the inner diameter of the lumen (in this case lumen 14) narrows somewhat as can be seen by comparing cross sections IA and IB.

Lumen extensions 12 and 13 are illustrated as being independent of each other, in the sense that they each extend distally from main body 11 but the two lumen extensions are not mechanically linked to each other except by whatever linkage is provided at the distal end of the main body. Other embodiments have lumen extensions that are temporarily mechanically linked together in any convenient manner, which may aid in advancement of the apparatus into the vessel. Possible linkages are formed by lightly fusing or adhering the lumen extensions to each other; or by a means similar to the resealable closures known generically as "zip locks" or similar terms. It is then also possible to provide a means to unlink the lumen extensions from each other after the apparatus is partially advanced into the vessel.

Also, as illustrated, it is preferred (but not required) that one lumen extension is shorter than the other; in the preferred embodiment illustrated, lumen extension 12 is shorter than lumen extension 13.

Referring to Figure IA, it may be seen that each of the lumens 14 and 15 is preferably circular in cross sectional shape, and separated from each other by distance d. Distance d is shown schematically as non-zero, but in general d may (and should) be as small a value as possible, i.e., lumens 14 and 15 may actually touch each other or be joined together (see also Figure 17).

While not illustrated in Figures 1 and 2, main body 12 may be a single piece construction or may be a combination of proximal and distal sections having different constructions from each other, provided that lumens 14 and 15 are provided in each section as otherwise described above.

Figures 1 and 2 also illustrate the preference for the apparatus 100 or 200 to have radiopaque features to identify the main body and each lumen, such as multiple optional markers 20 (e.g., radiopaque material wrapped around the apparatus, or filling a portion of the material forming the apparatus) and lumen extension tips 21. As is known in the art, such features are not clinically required but are very useful to enable the unwrapping of the guidewires to be visualized. The preferred arrangement is illustrated in Figures 1 and 2, but the scope of the invention is not determined by the number, type, and location of radiopaque features. A similar and also optional use, of markings would be at proximal locations along the length of main body 10 that would indicate to the physician the total distance that the apparatus has been advanced into the body.

Figure 2 illustrates an embodiment with respect to an apparatus 200 that is generally the same as apparatus 100 of Figure 1, with the notable difference being that the proximal openings of each lumen are located on side surfaces, as opposed to the proximal end, of the main body. While the two proximal openings are illustrated on opposite sides of the main body, this is only for purposes of illustration. In general, the proximal openings may be located at any convenient location on the main body intermediate between the proximal end and the distal end of the same (see also the discussion of Figures 7 and 8, below). The locations illustrated in Figure 2 are suitable for relatively shorter guidewires, such as the approximately 180 cm ("short") guidewires common in rapid exchange interventional procedures, as opposed to the proximal end locations illustrated in Figure 1, which are better suited for relatively longer guidewires, such as the approximately 300 cm ("long" or "full length") guidewires commonly used in over-the-wire ("OTW") interventional procedures.

Either or both lumens may be of either type, and thus there are three combinations for any so-called "dual-wire" procedure: short/short, short/long, and long/long. Most interventional procedures will employ the former, whereas the latter two combinations are preferred in interventional procedures that involve removal and replacement of guidewires.

Each of Figures 1 and 2 illustrates lumen extensions 12 and 13 that extend distally from the distal end of main body 11. This is the preferred configuration for the procedure of unwrapping previously deployed guidewires that have become entangled. It is also possible to use such embodiments in a procedure of preventing entanglement from occurring. In this procedure, the apparatus 100 or 200 is advanced into the body vessel before all (if any) of the guidewires are introduced into the vessel. Then, the guidewires are advanced distally through the lumens 14 and 15. The apparatus 100 or 200 prevents the guidewires from becoming entangled during advancement. Once the guidewires are advanced as desired, apparatus 100 or 200 is removed and the therapeutic procedure continues with the guidewires advanced and not entangled with each other. In such a preventative procedure, it is not necessary that lumen extensions 12 and 13 extend distally from the distal end of main body 11.

Figures 3-8 are expanded views of portions of a preferred embodiment incorporating some of the features of the embodiments of Figures 1 and 2 (except as specifically noted). Figure 3 is a partially magnified side view of the distal portion of the apparatus, illustrating that in the preferred embodiment, the two lumen extensions 12, 13 have the same height (outer diameter), which is approximately one-half that of the main body 11.

Figure 4 is a partially magnified bottom view of the most distal portions of the embodiment of Figure 3. As illustrated, the angle between the two lumen extensions 12, 13 is variable because the lumen extensions 12, 13 are distally independent of each other. Figure 5 is a partially magnified top view of a less distal portion of the embodiment of Figure 3, again illustrating the distal independence of the lumen extensions 12, 13. Figure 6 is a partially magnified top view of an intermediate portion of the main body, illustrating that it may comprise two distinct sections 11a and lib if desired.

The materials used for the distal shaft body could be any torqueable material or construction, according to principles known in the art. Some examples include, but are not limited to: plain multi-lumen polymer tubing, braided polymer tubing, hollow stranded core tubing, or hypotubes. The lumen extensions would generally be comprised of an inner tube (guidewire lumen) that consists of a thin polymeric material that may have a lubricious inner lining (example: Polyimide blended with polytetrafluoroethylene (PTFE) on the inner wall), and an outer layer comprising of a flexible polymeric material (example: polyether block amides, such as those known by the trade name PEBAX) that would create a tapered tip that smoothly transitions into the distal shaft body. Embedded into the lumen extensions would be any radiopaque material (example: Platinum markers) that would allow visibility of the lumen extensions on the fluoroscope. The radiopaque markings would be such that the physician would be able to see that the distal portions of the lumen extensions are "crossed" or "in-line" with each other. Additionally, the radiopaque markings that are on the proximal end of the distal lumen extensions (just distal to where they separate from each other), are intended to give the physician clear visualization that the guidewires have total separation when the device is pressed up against the carina of a vessel bifurcation.

Figures 7 and 8 are respective side and top views of a more proximal portion of an embodiment similar to that of Figure 2. These figures illustrate that the proximal openings of each lumen 14, 15 may be located on the side of the main body of apparatus 200 (as opposed to the proximal end as in Figure 1), and furthermore that the proximal openings may be located at any convenient location on the main body, as noted above with respect to Figure 2. Figures 7 and 8 also illustrate that the proximal opening of each lumen 14, 15 need not necessarily be circular, as implied by the schematic illustration of Figure 2. The shape of each opening is not a limitation on the scope of the invention. Figures 9-12 illustrate a more preferred embodiment of the version illustrated in Figures 2, 7, and 8. Figures 9 and 10 are respective top and angled side views of a proximal portion of the apparatus corresponding to that shown in Figures 7 and 8.

In Figures 9-12, lumens 14, 15 are arranged side-by-side, and are formed by wrapping a pair of hollow tubes within a hollow stranded core cable. Suitable tubes are readily available and the selection of the same is well within the skill of the art. Suitable cables are constructed from commercially available medical grade stranded wires.

The combination of lumens and core is covered by any suitable medical grade lubricious material over whatever length of the apparatus is required. The composition of the material and the manner in which it is created or applied are not critical to the scope of the invention. The use of such material is preferred because it provides desired hydrophilic and lubricious properties to the apparatus.

A cutout region 16 provides the location for the respective proximal openings of each lumen 14, 15. Cutout region 16 may be formed by an angular slice or skive into the coating and stranded core material, then into the exterior of the material forming each lumen 14, 15. This construction is preferred because it has a very smooth overall profile, as illustrated in Figures 11

(a side view) and 12 (back view).

In embodiments involving OTW procedures, it may be desirable to provide a conventional luer fitting at or adjacent the proximal end of the apparatus. This will be used to flush the lumens to prevent air from being trapped within them, in accordance with known techniques.

Figure 13 illustrates a preferred embodiment of an optional handle 300 for use in various embodiments. In use, handle 300 may be securely fixed to the proximal end of main body 10, and thus the entire device rotates as handle 300 is rotated. The handle 300 may be molded onto main body 10 using techniques known in the art.

Handle 300 comprises a main handle body 32 that is fixed to the proximal end of main body 10 such that the two have a common central axis. A proximal end 30 is attached to main handle body 32 so that it may freely rotate about that axis. A conventional snap fit is suitable.

Proximal end 30 may then butt against the palm of the physician, but even if it does not, rotation of main handle body 32 provides additional torque to rotate main body 10 and thus unwrap twisted guidewires. Once the device is at the location of entanglement (or bifurcation of the vasculature, as described in more detail below), the physician actively disentangles the guidewires by rotating shaft 32 either clockwise or counterclockwise as required. Even without such rotation, the device performs some unwrapping of twisted guidewires as a passive result of simply advancing the device into the body. It is also possible to twist the guidewires themselves to assist with the unwrapping.

Handle 300 preferably is provided with a flattened or otherwise suitable area 33 for optional product identification information, in whatever form is suitable for the applications (e.g., one- or two-dimensional barcode, model number, or serial number). It may also be provided with sunken or raised lettering (not shown) for identification or marketing purposes (e.g., company name, product name). Both proximal end 30 and main handle body 32 are preferred to be relatively high durometer material to reduce the friction between the two components and thus allow for free rotation about the common central axis. Optional gripping features 34 (which may be raised or depressed regions molded into the material of main handle body 32, or other materials molded into main handle body 32 at such locations) could be provided to increase the ability of the physician to grip and rotate handle 300. Such features are optional because physicians wear gloves that typically provide adequate ability to grip handle 300.

Figure 14 illustrates an embodiment similar to that of Figure 1 and thus common components of each embodiment are numbered identically. Apparatus 300 again comprises main body 11, but only a single lumen extension 12 extends distally from main body 11. Lumen 15 is defined by lumen extension 313 that itself lies attached to the exterior of main body 11 over the entire length of apparatus 300. In general, lumen extension 313 may or may not extend as fully in the proximal direction as the remainder of main body 11. Thus, the broadest scope of the invention includes embodiments in which the main body is simply combined with at least two lumens, and not just those in which the main body fully encloses such lumens.

Figure 15 schematically illustrates the principles of the embodiment of Figure 14 as applied to the RX embodiment of Figure 2.

Figure 16 illustrates an embodiment of the apparatus 500 in which main body 11 is a simple flexible wire (or similarly performing material), and lumens 14, 15 are merely loops of the same (or similar) construction combined with main body 11 and located at the distal end of the same. (As before, optional marker 20 may be provided to indicate the distance of advancement into the body.) Each lumen 14, 15 has a minimum (nearly zero) length, but each is sufficiently defined to enable unwrapping of guidewires (or the prevention of entanglement of guidewires) as otherwise described above with respect to other embodiments. The embodiment of Figure 16 may also be provided with an optional handle similar to or as illustrated in Figure 13.

Figure 17 illustrates that, in any embodiment, references to two lumens should be understood as including a structure in which a single passage has two distinct portions, a single guidewire being capable of fitting into one or the other portion, but not able to migrate or pass from one such portion to the other, even if the two portions are nonetheless partially joined together. Thus, each portion operates like a lumen as described above. As illustrated in Figure 17, this may be accomplished providing a narrower neck-like region between the two lumens. The amount of narrowing is determined by the overall geometry of the lumens, including the diameter of the guidewire(s) involved, but it is easily determined by one of ordinary skill in the art. Note that it is possible that the guidewires may contact each other within the neck-like common region, but the lubricious coatings commonly used on commercially available guidewires will minimize complications due to such contact. The use of such single passages may permit the overall profile of the apparatus to be smaller than in other embodiments.

Such single passages operate according to the following general principles. Two distinct portions of a single passage may function as distinct lumens if they maintain the relative axial relationship (i.e., prevent entanglement or permit unwrapping) of two guidewires despite the torque applied around the central axis of the apparatus. The guidewires may (and almost certainly do) rotate about their own respective central axes within the portions/lumens during application of such torque.

Figure 18 is a variation of Figure 17 that illustrates a concept applicable to all embodiments, not just those involving Figure 17. One or more additional lumens 1000 may be provided to enable application of therapy or performance of other functions known (or subsequently determined) to benefit from use of a lumen. For example, lumen 1000 could be used for inflation of a balloon to deploy a stent, in accordance with principles known in the art.

In this regard, adding features to existing devices that enable practice of the claimed invention is within the scope of the invention as contemplated by the inventors. Other possible constructions for other embodiments are possible. One is to directly extrude or otherwise manufacture the main body with integral lumens, i.e., a "one-piece" construction. Exterior braiding and a lubricious sheath could then be added, using principles known in the art. Another construction would be to use two distinct tubes (e.g., hypotubes) attached (by tape, welding or other equivalent techniques) in place of the one-piece construction, with the braiding and outer sheath added.

The invention could be implemented in an embodiment having three or more lumens, but preferred embodiments have exactly two lumens, because that is sufficient to straighten out three or more guidewires by simply straightening out pairs of guidewires at a time. Embodiments having three or more lumens are not preferred because they provide very little ability to completely unwrap two adjacent guidewires by twisting the apparatus in alternating clockwise and counterclockwise directions. Although, in some trifurcated vessel procedures, an embodiment having three lumens could be preferred for placement of the second or third guidewires through the device, as a proactive measure to prevent wire wrap from occurring.

As illustrated in the Figures, the lengths of the lumens are preferred to be different from each other, but this is not necessarily required.

In all embodiments, whether specifically depicted in the embodiments illustrated in the

Figures or not, the diameters of lumens are not necessarily the same. Similarly, the diameter of any lumen is not necessarily constant over the entire length of that lumen. In fact, as noted above, it is preferred that the diameter of each lumen be smaller at the distal end than at other portion(s) of the length of the lumen.

In this regard, the term "diameter" should not be read as an implicit requirement that any lumen is necessarily circular in cross-section. Lumens having circular cross-sections are preferred, but not required. Lumens having circular cross-sections also are typically easier to manufacture than lumens having non-circular cross-sections. Thus, less preferred embodiments may have oval or elliptical cross-sections; and if so, "diameter" should be understood to apply to either the major or minor axes of the ellipse. Other possible (but even less preferred) lumen cross-sections include (but are not limited to) triangle, square, rectangular, rhombus, trapezoid, pentagon, hexagon, heptagon, etc., with the term "diameter" being understood by analogy. In all embodiments, whether specifically depicted in the embodiment illustrated in the Figures or not, the intra-lumen spacing d (see Figure IA) is preferably as small as possible. This enables a corresponding reduction in the overall diameter of the apparatus, which in turn is desirable because it may be required for situations involving narrow body cavities.

In all embodiments, whether specifically depicted in the embodiment illustrated in the

Figures or not, it is preferred that the apparatus not have any pre-formed bends. Such bends generally interfere with the torqueability and steerability, although in specialized applications or clinical settings it may be desirable to provide one or more bends.

There are relatively few structural or compositional requirements that are not within the skill of the art of design and construction of similar interventional medical devices. In general, the apparatus should be biocompatible, provide a suitable balance between flexibility and torqueability, i.e., not so much of the former as to provide too little of the latter. The inner surfaces of the lumens should be lubricious to ensure smooth advancement over the guidewires, just at the outer surface of the apparatus should be lubricious to ensure smooth advancement through the body vessel.

In accordance with common and accepted clinical usage, some embodiments may be sterilized before use and kept in sterile packaging until immediately prior to use. Embodiments are preferably used only once (because of contact with body fluids), although embodiments that may be repeatedly sterilized and/or reused are possible.

While removal of the apparatus from the body is not a structural requirement, it may be a practical or clinical requirement of methods of using the apparatus. One reason for this is because the apparatus would be in the way during the remainder of the intended procedure, e.g., advancing any therapeutic catheter over any of the guidewire(s). On the other hand, it may be clinically possible to leave the apparatus in place and use it as a platform for subsequent delivery of therapeutic measures. But, in the most preferred clinical embodiments, the apparatus is specifically not intended for use as a therapeutic device.

One clinical setting that may benefit from a therapeutic version is a so-called bifurcated lesion, particularly a coronary bifurcated lesion. This occurs when plaque is present at the site where one vessel branches from another. As is known in the art, bifurcated areas of the vascular system are a common location for the buildup of plaque (an estimated thirty percent of patients treated for coronary artery disease have lesions at bifurcations), but the lesions are particularly difficult to treat with conventional stents because of the risk of blocking blood flow to the side or main vessel.

In the context above, to "advance" a guidewire or other device means to at least partially move it in the intended direction, and should not be read as implying that the guidewire or device has reached its final intended location unless specifically stated or clearly required by context.

The scope of the invention does not depend on the construction or composition of the guidewire; nor does it require that the objects to be unwrapped (or to be kept from becoming wrapped together) be "guidewires" as that term is used in the art of percutaneous transluminal coronary angioplasty (PTCA) and similar interventional medical procedures, such as percutaneous transluminal angioplasty (PTA), percutaneous transluminal renal angioplasty (PTRA), and the like. Appropriately designed embodiments could be used to unwrap long, slender devices inserted into vessels, such as catheters, and not just guidewires. Such long, slender devices are not structural features of the multi-lumen apparatus represented described above, and thus "guidewire" is a synonym for all such devices in the following claims.

Claims

We claim:

1. An apparatus for use with guidewires prone to entanglement during advancement into a vessel, the apparatus comprising a main body, having proximal and distal ends, combined with at least two lumens supported by the main body; in which the apparatus has sufficient flexibility to be advanced through the vessel.

2. The apparatus of claim 1, in which the apparatus prevents entanglement of the guidewires by being advanced through the vessel before at least one of the guidewires is advanced into the vessel through one of the lumens of the apparatus.

3. The apparatus of claim 1, in which the guidewires are advanced into the vessel before the apparatus, and the apparatus disentangles the guidewires by being advanced through the vessel over the guidewires, each guidewire passing though one of the lumens.

4. The apparatus of claim 1, in which the apparatus is further characterized by sufficient torqueability to enable axial rotation of the apparatus to unwrap the guidewires.

5. The apparatus of claim 1, further comprising at least one lumen extension extending distally from the distal end of the main body; and further in which at least one lumen extends distally from the distal end of the main body throughout its respective lumen extension to a distal opening of such lumen.

6. The apparatus of claim 1, in which at least one lumen has a proximal opening on the proximal end of the main body.

7. The apparatus of claim 1, in which at least one lumen has a proximal opening intermediate between the proximal and distal ends of the main body.

8. The apparatus of claim 1, in which the main body comprises a flexible material, and each lumen comprises a loop at the distal end of the main body.

9. The apparatus of claim 1, in which each lumen is a portion of a single passage having two distinct portions, such that a single guidewire may fit into a portion but not migrate to another portion.

10. The apparatus of claim 1, in which each lumen is a portion of a single passage and the two lumens are partially joined together.

11. The apparatus of claim 1, in which each lumen is a portion of a single passage and the passage comprises a neck-like region between the two lumens.

12. A method for unwrapping guidewires advanced into a vessel, the guidewires each having respective proximal ends and distal ends, comprising:

a) providing an apparatus comprising a main body combined with at least two lumens;

b) threading each lumen onto respective proximal ends of guidewires;

c) distally advancing the apparatus through the vessel over the guidewires; and

d) twisting the main body as necessary to unwrap the guidewires.

13. The method of claim 12, further comprising :

e) removing the apparatus from the unwrapped guidewires.

14. The method of claim 12, in which the vessel is a portion of vasculature.

15. The method of claim 12, in which the vessel is a portion of one of lymphatic, urinary, reproductive, respiratory, or digestive systems.

16. The method of claim 12, in which at least one lumen is defined within the main body.

17. The method of claim 12, in which at least one lumen is defined outside the main body.

18. The method of claim 12, in which the main body defines exactly two lumens.

19. A method for preventing the entanglement of guidewires within a vessel, each guidewire having respective proximal ends and distal ends, the method comprising:

a) providing an apparatus comprising a main body having a distal end, combined with at least two lumens,

b) distally advancing the apparatus into the vessel;

c) advancing at least one guidewire into a respective lumen; and

d) removing the apparatus from the vessel over the proximal ends of the guidewires.

20. The method of claim 19, in which the vessel is a portion of vasculature.

21. The method of claim 19, in which the vessel is a portion of one of lymphatic, urinary, reproductive, respiratory, or digestive systems.

22. The method of claim 19, in which at least one lumen is defined within the main body.

23. The method of claim 19, in which at least one lumen is defined outside the main body.

24. The method of claim 19, in which the main body defines exactly two lumens.

25. The method of claim 19, in which a first guidewire is advanced into the vessel prior to advancing the apparatus into the vessel, after which the apparatus is advanced into the vessel over the first guidewire, followed by advancing a second guidewire through the respective lumen.

26. The method of claim 19, in which the second guidewire is initially outside the respective lumen.

27. The method of claim 19, in which the second guidewire is initially preloaded within the respective lumen.

28. An apparatus for unwrapping guidewires advanced into a vessel or preventing the entanglement of guidewires to be advanced into a vessel, comprising a main body, having proximal and distal ends, combined with two lumens defined within the main body; and at least one lumen extension extending distally from a distal end of the main body, in which at least one lumen extends distally from the distal end of the main body throughout its respective lumen extension to a distal opening of such lumen; the apparatus having sufficient flexibility to be advanced through the vessel over at least one of the guidewires, and sufficient torqueability to enable axial rotation of the apparatus to unwrap or prevent entanglement of the guidewires.

29. The apparatus of claim 28, further comprising a handle connected to the proximal end of the main body.

30. The apparatus of claim 28, in which at least one lumen has a proximal opening on the proximal end of the main body.

31. The apparatus of claim 28, in which at least one lumen has a proximal opening intermediate between the proximal and distal ends of the main body.

32. The apparatus of claim 28, in which each lumen is a portion of a single passage having two distinct portions, such that a single guidewire may fit into a portion but not migrate to another portion.

33. The apparatus of claim 28, in which each lumen is a portion of a single passage and the two lumens are partially joined together.

34. The apparatus of claim 28, in which each lumen is a portion of a single passage and the passage comprises a neck-like region between the two lumens.