US 20070255217 A1
A guide wire for advancing a medical device such as a catheter through a patient's body lumen which has an elongated core with proximal and distal core section, a flexible tubular member such as a coil on the distal end. The wire core includes surface textures that are translated into the overlying coating. Alternatively, the coating has its own surface texture. The surface textures include randomly or non-randomly spaced bumps, divots, ridges, helical grooves, longitudinal grooves, undulations, etc.
1. An intraluminal guide wire, comprising:
an elongated core having a proximal core section and a distal core section having a distal end, wherein at least a section of the elongated core includes randomized and non-randomized tactile surface contours, wherein the surface contours are spaced apart in a range of about 0.05 cm to 2 cm and have a surface-to-peak amplitude of about 0.0002 to 0.002 inch;
an uninterrupted polymer coating with a generally constant outside diameter adhering to at least a portion of the elongated core and having a surface contour that follows the randomized and non-randomized tactile surface contours in the elongated core; and
a flexible tubular member disposed over the distal core section.
2. The intraluminal guide wire of
3. The intraluminal guide wire of
4. The intraluminal guide wire of
5. The intraluminal guide wire of
6. The intraluminal guide wire of
7. The intraluminal guide wire of
8. The intraluminal guide wire of
9. The intraluminal guide wire of
10. The intraluminal guide wire of
11. The intraluminal guide wire of
12. The intraluminal guide wire of
13. The intraluminal guide wire of
14. An intraluminal guide wire, comprising:
an elongated core having a proximal core section and a distal core section including a taper transitioning to a distal end, wherein an exterior surface of the distal core section is substantially smooth and without interruptions;
a polymer coating of generally uniform thickness adhering to at least a portion of the distal core section with a coating profile following a tapered profile of the elongated core, the polymer coating having an exterior surface with at least one of randomized and non-randomized surface contours that can be detected by human touch; and
a flexible tubular member disposed over the distal core section.
15. The intraluminal guide wire of
16. The intraluminal guide wire of
17. The intraluminal guide wire of
18. A method for providing an intraluminal guide wire, comprising:
providing an elongated core having a proximal core section and a distal core section having a substantially smooth exterior surface;
tapering a profile of the elongated core to transition into a distal end;
heating and extruding a polymer through a die to adhere to at least a portion of the elongated core to create a polymer coating; and
imparting into an exterior surface of the polymer coating at least one of randomized and non-randomized surface contours that are independent from the profile of the elongated core, wherein the at least one of the randomized and non-randomized surface contours have sufficient texture to be detectable by human touch.
19. The method of
This application is a continuation application of co-pending U.S. application Ser. No. 10/664,004, filed Sep. 16, 2003, whose entire contents is hereby incorporated by reference.
This present invention relates to the field of guide wires used for advancing intravascular devices such as stent delivery catheters, balloon dilatation catheters, and atherectomy catheters within a body lumen. More specifically, the present invention relates to a guide wire with a polymer coating having a textured surface.
Conventional guide wires for angioplasty, stent delivery, atherectomy and other vascular procedures usually comprise an elongated core with one or more tapered sections near the distal end thereof and a flexible body such as a helical coil or a tubular body of polymeric material disposed about the distal portion of the elongated core. A shapable member, which may be the distal extremity of the elongated core or a separate shaping ribbon which is secured to the distal extremity of the elongated core, extends through the flexible body and is secured to the distal end of the flexible body by soldering, brazing, or welding, which forms a rounded distal tip. Torquing means are provided on the proximal end of the elongated core to rotate, and thereby steer, the guide wire while it is being advanced through a patient's vascular system.
Further details of guide wires and devices associated therewith for various interventional procedures can be found in, for example, U.S. Pat. No. 4,748,986 (Morrison et al.); U.S. Pat. No. 4,538,622 (Samson et al.); U.S. Pat. No. 5,135,503 (Abrams), U.S. Pat. No. 5,341,818 (Abrams et al.), and U.S. Pat. No. 5,345,945 (Hodgson et al.), which are hereby incorporated herein in their entirety by reference thereto.
In a typical coronary procedure using a guide wire, a guiding catheter having a preformed distal tip is percutaneously introduced into a patient's peripheral artery, e.g., femoral or brachial artery, by means of a conventional Seldinger technique and advanced and steered therein until the distal tip of the guiding catheter is seated in the ostium of a desired coronary artery.
There are two basic techniques for advancing a guide wire into the desired location within the patient's coronary anatomy through the in-place guiding catheter. The first is a preload technique which is used primarily for over-the-wire (OTW) devices, and the second is the bare wire technique which is used primarily for rail type systems.
With the preload technique, a guide wire is positioned within an inner lumen of an OTW device such as a dilatation catheter or stent delivery catheter with the distal tip of the guide wire just proximal to the distal tip of the catheter and then both are advanced through the guiding catheter to the distal end thereof. The guide wire is first advanced out of the distal end of the guiding catheter into the patient's coronary vasculature until the distal end of the guide wire crosses the arterial location where the interventional procedure is to be performed, e.g., a lesion to be dilated or a dilated region where a stent is to be deployed. The catheter, which is slidably mounted onto the guide wire, is advanced out of the guiding catheter into the patient's coronary anatomy over the previously introduced guide wire until the operative portion of the intravascular device, e.g., the balloon of a dilatation or a stent delivery catheter, is properly positioned across the arterial location. Once the catheter is in position with the operative means located within the desired arterial location, the interventional procedure is performed. The catheter can then be removed from the patient over the guide wire. Usually, the guide wire is left in place for a period of time after the procedure is completed to ensure reaccess to the arterial location if it is necessary. For example, in the event of arterial blockage due to dissected lining collapse, a rapid exchange type perfusion balloon catheter such as described and claimed in U.S. Pat. No. 5,516,336 (McInnes et al.), can be advanced over the in-place guide wire so that the balloon can be inflated to open up the arterial passageway and allow blood to perfuse through the distal section of the catheter to a distal location until the dissection is reattached to the arterial wall by natural healing.
With the bare wire technique, the guide wire is first advanced by itself through the guiding catheter until the distal tip of the guide wire extends beyond the arterial location where the procedure is to be performed. Then a rail type catheter, such as described in U.S. Pat. No. 5,061,273 (Yock) and the previously discussed McInnes et al., which are incorporated herein by reference, is mounted onto the proximal portion of the guide wire which extends out of the proximal end of the guiding catheter outside of the patient. The catheter is advanced over the catheter, while the position of the guide wire is fixed until the operative means on the rail type catheter is disposed within the arterial location where the procedure is to be performed. After the procedure, the intravascular device may be withdrawn from the patient over the guide wire or the guide wire advanced farther within the coronary anatomy for an additional procedure.
There has been an interest in creating different surface profiles for the guide wire core. The interest arose primarily to address the issue of friction between the contact surface of the guide wire and the catheter lumen through which it passes or the body lumen of the patient. One attempt is the use of a sleeve at the distal portion of the core as seen in, for example, U.S. Pat. No. 5,404,887 (Prather). Another approach to reducing the surface contact between the guide wire and a catheter lumen or body lumen is shown in U.S. Pat. No. 6,296,616 (McMahon).
The present invention in various embodiments is directed to reducing the surface contact of the guide wire within a catheter lumen or a body lumen, and providing a unique tactile feedback to the clinician or physician thus improving his or her control and awareness of wire movement. The present invention further diminishes the potential for generating particulate in the lubricious hydrophilic coating during motion of the guide wire in a catheter, because of the reduced contact between the catheter lumen and the guide wire surface. Lastly, the present invention provides a guide wire surface that minimizes the phenomenon of “watermelon seeding,” which describes the inadvertent shifting of the guide wire relative to the lesion when the two structures catch and then overslip due to the low friction of the guide wire coating.
In one embodiment, the present invention contemplates an intraluminal guide wire comprising an elongated core having a proximal core section and a distal core section having a distal end, wherein at least a section of the elongated core includes at least one of randomized or non-randomized tactile surface contours. The guide wire preferably includes an uninterrupted polymer coating made of generally uniform thickness adhering to at least a portion of the elongated core and having a surface contour that follows the at least one of randomized and non-randomized tactile surface contours in the elongated core. Thus, in this embodiment, the randomized or non-randomized tactile surface contour in the elongated core and elsewhere is translated into a like contour at the polymer coating surface. In other words, bumps in the surface of the wire core translate to bumps in the surface contour or texture of the polymer coating. Preferably, the coating has a generally uniform thickness over the surface contours as well as the flat areas of the wire core.
In another embodiment of the present invention, a guide wire comprises an elongated core having a proximal core section and a distal core section including a taper transitioning to a distal end wherein an exterior surface of the distal core section is relatively smooth. In one variation, a polymer coating of uniform thickness adheres to at least a portion of the distal core section and follows the profile of the taper. In another variation, the outside diameter (O.D.) of the polymer coating does not follow the tapered profile although the inside diameter (I.D.) does follow the taper. This results in a constant O.D. for the guide wire even at the taper and the coating has a variable thickness. In either variation, the polymer coating has at least one of randomized or non-randomized tactile surface contours.
The surface contours in this embodiment are generated in the surface of the polymer coating only and do not originate from the surface texture of the underlying wire core. With the polymer coating that has a generally uniform thickness along the length of the guide wire, the specific coating section with its surface irregularity creating the surface contour or texture is still loosely described as having a uniform thickness. And the uniform thickness polymer coating follows the profile of the core such as in a tapered or step down transition.
In various embodiments of the present invention, the surface contour can include a bump, a divot, a helical groove pattern, a rib, an undulation, a longitudinal groove, ridges and dips, a circumferential groove, or the like. As mentioned above, these tactile surface contours may be generated in the surface of the polymer coating only or may originate in the surface of the wire core which then is translated into the outer surface of the polymer coating.
The present invention further contemplates a method for providing an intraluminal guide wire comprising the steps of providing an elongated core having a proximal core section and a distal core section having a smooth exterior surface. The method further includes tapering the profile of the elongated core to transition into a distal end, and heating and extruding a polymer through a die to adhere to at least a portion of the elongated core to create a polymer coating of generally uniform or variable thickness, and imparting into the polymer coating at least one of randomized and non-randomized tactile surface contours.
In various alternative embodiments, the present invention includes localized heating of the polymer coating to create the surface texture. The localized heating may originate from a laser or a heat source that is brought into proximity of the polymer coating in cycles or randomly at various predetermined feed rates over the wire core. Moreover, the surface contours or texture in the wire core or even the polymer coating can be generated by sand, shot, or particle blasting the wire core or by drawing through a die to create a ridge, for example. These and other advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying exemplary drawings.
The present invention is directed to an elongated intracorporeal device such as a guide wire having a surface texture. The surface texture depending on location is helpful for minimizing friction between the guide wire and the catheter lumen or body lumen, and provides tactile feedback to the physician if located at the proximal end. In various embodiments, the tactile and friction-reducing surface texture in the guide wire coating is created from texturing the guide wire core underneath which is translated to the coating surface. Alternatively, the texturing is created solely in the surface of the coating that overlies a smooth surface of the wire core.
The surface coating 20 may only partially cover the guide wire core 22 or may envelope the entire core altogether. Toward the distal end 24 of the guide wire 10 is a flexible member 26. Preferably the flexible member 26 is one or more helical coils welded, bonded, soldered, or otherwise attached to the distal core section 14. In the embodiment shown, the flexible member 26 is attached at its proximal end by a weld or solder mass 28 and at its distal end by a solder ball 30 or similar rounded tip. Furthermore, the guide wire 10 features a flattened distal tip that extends into the solder ball 30.
The guide wire 42 of
Indeed, the bumps 58 have sufficient amplitude or height to change the surface contour, but the generally straight or tapered profile of the wire core remains unchanged. In other words, the bumps 58 change the surface texture of the wire core, but do not change and are independent of the overall profile of the wire core, be it straight, tapered, stepped, curved, or any combination thereof.
Overlying the wire core 64 is a coating 60 that in this embodiment preferably extends from the proximal end 56 to a weld mass 62. Importantly, the coating 60 follows or conforms to the surface texture delineated by the bumps 58 as well as the overall profile delineated by the straight, curved, or tapered profiles of the wire core 64. In other words, as the outside diameter of the wire core 68 changes, so does the outside diameter of the coating 60 such that the coating thickness is relatively constant along the length of the wire core 68.
In the embodiment shown in
The bumps 58 in the wire core 64 can be created by liquid metal sputtering or like metallization techniques, or from solder, braze, weld, adhesive beads deposited onto the surface of the wire core 64. The coating 60 is then built up on the bumpy substrate thus creating the bumpy textured surface shown in
The surface of the wire core 68 is relatively smooth without any surface texture or contour. However, a coating 76 deposited on the smooth surface wire core 68 itself has surface textures in the form of spaced apart divots 78. As seen in the partial sectional view of
The pattern of indentations, pits, or divots 90 shown in
If this process proceeds without disturbance, a generally uniform and concentric coating is adhered to the surface of the wire core. However, if the feed speed through the die 110 is changed, or the feed is stopped, for example, a ridge 108 is formed as shown in
Other parameters that can be adjusted to build the ridges 108 in
The present invention coating as mentioned in the above embodiments is preferably a polyurethane polymer, although any polymer that meets design requirements can be used. The spacing between surface textures or contour interruptions range between about 0.1 cm to 0.3 cm along the length of the wire core. In one embodiment, the textured polymer coating is located on the distal working section of the wire core, which is typically between 25 to 45 cm from the distal tip of the wire core and more preferably the distal 45 cm, although the polymer coating may be terminated at the distal tip coils as shown in
In various alternative embodiments, the surface coating can be made from a fluoropolymer or fluoropolymer resin materials. The surface could then be randomly or non-randomly textured, resurfaced, or scarred using a laser, UV light, radiation, or other forms of heat and energy transmission. As mentioned earlier, the texturing of the surface of the wire core can be any mechanical means such as textured rollers, scraping, dimpling, impingement, sand blasting using aluminum oxide, carbide, sodium bicarbonate powders, stamping, pad printing, etc.
The fluoropolymer coating may be co-extruded onto the wire core through the process described in connection with
Although not shown, the present invention contemplates more than one coatings being applied to the wire core. Therefore, the embodiments shown in the drawing figures may have multiple coatings yet still reflect the surface textures depicted.
The wire core 22 may have an optional lubricious coating such as a fluoropolymer, e.g., Teflon available from DuPont, that extends the length of the wire core or a portion thereof. The distal core sections 14, 34, may optionally be covered with a lubricious coating such as that used by Advanced Cardiovascular Systems, Inc. under the commercial name MICROGLIDE. Hydrophilic coatings may also be employed to cover the wire core partially or entirely.
The guide wires of the present invention may have typical guide wire dimensions. Guide wire length may generally be about 90 to about 300 cm, and for use within a patient's coronary anatomy commercially available guide wires are typically about 175 cm in length. Longer and longer guide wires, e.g., up to 190 cm in length, are being offered commercially by a variety of suppliers. The proximal core section 12 may have a length of about 65 to about 280 cm, preferably about 150 to about 200 cm and a diameter generally about 0.008 to about 0.035 inch (0.20-0.89 mm), typically about 0.010 to about 0.020 inch (0.25-0.51 mm) for coronary artery uses. The distal core section is preferably much shorter than the proximal core section and generally is about 6 to about 40 cm, preferably about 8 to about 30 cm in length and tapers in the distal direction in one or more steps to smaller cross-sectional dimensions.
The tapered portion of the distal core section is preferably followed distally with a manually shapable flattened core segment or shaping ribbon of about 1 to 4 cm in length which preferably has essentially constant transverse dimensions, e.g., 0.0005-0.002 inch (0.013-0.051 mm) by 0.002-0.006 inch (0.051-0.152 mm), typically about 0.001 by 0.003 inch (0.025-0.076 mm). A helical coil having transverse outer dimensions about the same as or slightly less than the proximal core section is secured by its distal end to the flattened distal tip of the core member, e.g., by means of solder, and by its proximal end at an intermediate position on the tapered distal core section so that the distal end of the tapered core section resides within the interior of the coil. The helical coil 14 may be formed all or in part of stainless steel, a suitable radiopaque material such as platinum or alloys thereof or other material such as stainless steel coated with a radiopaque material such as gold. The wire from which the coil is made generally has a transverse diameter of about 0.0015 to about 0.003 inch (0.04-0.08 mm) for coronary applications and up to 0.07 inch (0.18 mm) for peripheral applications. The overall length of the coil 14 is about 2 to about 15 cm, preferably about 2 to about 6 cm. Multiple turns of the coil 14 may be expanded to provide additional flexibility.
Unless otherwise described herein, conventional materials and manufacturing methods may be used to make the guiding members of the present invention. Additionally, various modifications may be made to the present invention without departing from the scope thereof. Although individual features of embodiments of the invention may be shown in some of the drawings and not in others, those skilled in the art will recognize that individual features of one embodiment of the invention can be combined with any or all of the features of another embodiment.