US20030191492A1 - Radial coil expandable medical wire - Google Patents

Abstract

An expandable medical wire can be used to entrain biological or foreign material during a medical procedure, such as lithotripsy. The wire also can be used to remove the material safely from the body. Generally, the wire includes a sleeve and a core, where the sleeve, the core, or both include a portion or portions that can be deployed to form an expanded coiled configuration. The expanded coiled configuration can be collapsed to facilitate positioning the wire within an anatomical lumen. In addition, the wire can be used as a conventional guide wire or as a self-anchoring guide wire.

Description

TECHNICAL FIELD
• The invention generally relates to deployable medical devices for insertion into anatomical lumens.[0001]
BACKGROUND INFORMATION
• Blockages and obstructions can develop in certain areas of the body, such as in the kidneys, pancreas, esophagus, and gallbladder. Minimally invasive medical procedures generally cause limited trauma to the tissue of a patient and can be used to eliminate problematic obstructions. Lithotripsy and ureteroscopy, for example, are used to treat urinary calculi, e.g., kidney stones, in the ureter of patients.[0002]
• Lithotripsy is a medical procedure that uses energy in various forms, such as acoustic or electrical shock waves, pneumatic or hydraulic pulsation, or laser beams, to break up biological concretions, such as urinary calculi. The force of the energy, when applied either extracorporeally or intracorporeally, usually in focused and continuous or successive bursts, comminutes a kidney stone into smaller fragments that may be extracted from the body or allowed to pass through urination. With the help of imaging tools, such as transureteroscopic video technology and fluoroscopic imaging, the operator of the lithotripter device can monitor the progress of the medical procedure and terminate treatment when residual fragments are small enough to be voided or removed. Examples of such obstructions and the effects of treatment can be found in the published patent application US 2001/0031971, the disclosure of which is incorporated by reference herein in its entirety.[0003]
• Intracorporeal fragmentation of urinary calculi can prove problematic, because stones and/or stone fragments in the ureter may become repositioned closer to and possibly migrate back toward the kidney, thereby requiring further medical intervention to prevent aggravation of the patient's condition.[0004]
• Many known stone extraction devices are rigid and lack the maneuverability and flexibility to engage and disengage repeatedly a stone without harming the surrounding tissue. For example, if a stone is still too large to be extracted without further fragmentation, it can be difficult to disengage the stone from such an extraction device without damaging the delicate lining of the ureteral wall.[0005]
SUMMARY OF THE INVENTION
• The invention generally relates to preventing migration of material during a medical procedure, and to safely and efficiently ensnaring and extracting material from a body. It is desirable to be able to extract such material from the body using a single instrument, which prevents the need for successive instrumentation. A medical device according to the invention can be used to repeatedly ensnare and extract or sweep material (such as stones, stone fragments, and other biological and/or foreign material) while minimizing trauma to surrounding tissue. Accordingly, the device can be deployed and collapsed repeatedly, as and when required during the medical procedure.[0006]
• In one aspect, the invention is directed to a medical device including an elongate core and an elongate sleeve. The sleeve includes a lumen that extends longitudinally within at least a portion of the elongate sleeve. The core is slidably disposable within the lumen of the sleeve. The sleeve also includes a plurality of coils that are configured in a conical shape when the core is removed from a section of the lumen extending through the plurality of coils. The sleeve assumes a substantially linear configuration when the core is inserted within the section of the lumen extending through the plurality of coils.[0007]
• The conical shape formed by the plurality of coils can be used to ensnare objects in an anatomical lumen. When the sleeve is in the substantially linear configuration, a portion of the sleeve can be advanced beyond an object in an anatomical lumen. The coils can then be allowed to assume their conical shape by removing the slidable core to form a structure capable of ensnaring objects in the anatomical lumen. The core can be extended back through the lumen of the sleeve to return the sleeve into the substantially linear configuration for repositioning the device in the anatomical lumen. The conical shape can then be redeployed by retracting the core from the section of the lumen extending through the plurality of coils. Thus, reversible transformation of the coiled and linear configurations of the sleeve can facilitate repeated positioning and deployment of the medical device in appropriate locations in an anatomical lumen.[0008]
• In one embodiment of the invention, the plurality of coils forming a conical shape are located a predetermined distance from a proximal end of the sleeve. In another embodiment, the sleeve further includes at least one coiled element located in a portion of the sleeve distal to the plurality of coils. The at least one coiled element forms when the core is removed from a section of the lumen extending through the at least one coiled element and assumes a substantially linear configuration when the core is inserted into the section of the lumen extending through the at least one coiled element. The at least one coiled element can be used for anchoring the medical device and the conical shape can be used for ensnaring objects in the anatomical lumen.[0009]
• In another aspect, the invention is directed to a medical device including an elongate sleeve and an elongate core. The elongate sleeve includes a first portion and a second portion that is more rigid than the first portion and a lumen that extends longitudinally within at least a portion of the elongate sleeve. The core is slidably disposable within the lumen and includes a section that changes shape when disposed within the first portion of the sleeve causing an outer diameter of the sleeve to increase. The core is retained in a substantially linear configuration when the section that changes shape is disposed in the second portion of the sleeve.[0010]
• The first portion and the second more rigid portion of the sleeve can have different wall thicknesses. In one embodiment, the first portion of the sleeve has a wall thickness substantially less than the wall thickness of the second portion of the sleeve. In another embodiment, the first portion includes an expandable balloon. In yet another embodiment, the section that changes shape forms a coiled configuration when disposed in the first portion.[0011]
• In yet another aspect, the invention is directed to a medical device that includes an elongate sleeve and an elongate core. The sleeve includes a lumen that extends longitudinally within at least a portion of the elongate sleeve and a sleeve section that changes shape. The elongate core is slidably disposable within the lumen of the sleeve and includes a core section that changes shape. Each of the sleeve and core sections retain a substantially linear configuration when restrained and form a substantially coiled configuration when aligned. The sleeve and core sections form a substantially coiled configuration when unrestrained.[0012]
• In one embodiment, the coiled configuration of both the sleeve and the core can be substantially equal in shape and size. In another embodiment, each of the sleeve and core sections are adapted to remain in the coiled configuration when at least partially aligned. In yet another embodiment, each of the sleeve and core sections retain the substantially linear configuration when at least partially misaligned.[0013]
• In various embodiments of the two foregoing aspects of the invention, the sections that change shape can include at least one coil. The sections that change shape can also include a plurality of coils that form different shapes, such as conical, spherical, helical, frusto-conical, or combinations thereof. In a particular embodiment, the shape formed by the plurality of coils is a generally conical shape.[0014]
• In all the foregoing aspects of the invention, the core and the sleeve can be made from the same or different materials. In one embodiment, the sleeve includes a shape-memory material. In another embodiment, the core includes a shape-memory material. In yet another embodiment, both the sleeve and the core include a shape-memory material. Shape-memory materials are materials that can be formed into a particular shape, retain that shape during resting conditions, (e.g., when little or no external forces are applied to the shape), be deformed into a second shape upon subjecting the initial shape to a sufficiently high external force, and revert back to substantially the initial shape once the external forces are removed or at least lessened. Examples of shape-memory materials include synthetic plastics, stainless steel, and superelastic, metallic alloys, such as nickel/titanium (commonly referred to as nitinol), copper, cobalt, vanadium, chromium, and iron.[0015]
• In addition, the sleeve and the core can have essentially any cross-sectional shape, such as polygonal, arcuate, or combinations of polygonal and arcuate elements. In the present application, the term polygonal is used to denote any shape including at least two line segments, such as rectangles, trapezoids, and triangles. Examples of arcuate shapes include circular and elliptical. Further, the sleeve can include a coating disposed on an external surface of the sleeve. The coating can be a polymeric material, for example, polytetraflouroethylene, expanded polytetraflouroethylene, ethylene-tetrafluoroethylene, and silicone. The coating can cover a substantial portion of the external surface of the sleeve.[0016]
• These and other objects, along with advantages and features of the present invention herein disclosed, will become apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations.[0017]
BRIEF DESCRIPTION OF THE DRAWINGS
• In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the present invention are described with reference to the following drawings, in which:[0018]
• FIG. 1A is a partially sectioned schematic view of one embodiment of a medical device in accordance with the invention;[0019]
• FIG. 1B is another partially sectioned schematic view of the medical device of FIG. 1A, with a sleeve in a substantially linear configuration;[0020]
• FIG. 1C is a cross-sectional view of the medical device of FIG. 1A taken at[0021]line1C-1C;
• FIG. 2A is a cross-sectional schematic view of the medical device of FIG. 1A with the invention positioned inside the anatomical lumen;[0022]
• FIG. 2B is a partially sectioned schematic view of the medical device of FIG. 2A deployed within the anatomical lumen;[0023]
• FIG. 2C is another partially sectioned schematic view of the medical device of FIG. 2A deployed within the anatomical lumen;[0024]
• FIG. 3A is a partially sectioned schematic view of another embodiment of a medical device in accordance with the invention;[0025]
• FIG. 3B is cross-sectional schematic view of the medical device of FIG. 3A, with a sleeve in a substantially linear configuration;[0026]
• FIG. 4A is a cross-sectional schematic view of yet another embodiment of a medical device in accordance with of the invention;[0027]
• FIG. 4B is a cross-sectional schematic view of the medical device of FIG. 4A taken at[0028]line4B-4B;
• FIG. 5A is a cross-sectional schematic view of an elongate sleeve for use with an embodiment of a medical device in accordance with the invention;[0029]
• FIG. 5B is a schematic view of an elongate core for use with an embodiment of a medical device in accordance with the invention;[0030]
• FIG. 5C is a cross-sectional schematic view of a medical device including the elongate sleeve of FIG. 5A and the elongate core of FIG. 5B;[0031]
• FIG. 5D is a partially sectioned schematic view of the medical device of FIG. 5C in one possible deployed configuration;[0032]
• FIG. 5E is another partially sectioned schematic view of the medical device of FIG. 5C in another possible deployed configuration;[0033]
• FIG. 6A is a partially sectioned schematic view of another embodiment of a medical device in accordance with the invention, wherein each of the sleeve and core sections are in a coiled configuration;[0034]
• FIG. 6B is a cross-sectional schematic view of the medical device of FIG. 6A, with each of the sleeve and core sections restrained in a substantially linear configuration;[0035]
• FIG. 6C is a partially sectioned schematic view of the medical device of FIG. 6A, with the sleeve and core sections in aligned and coiled configurations;[0036]
• FIG. 7A is a schematic view of a spherically shaped coil configuration;[0037]
• FIG. 7B is a schematic view of a helically shaped coil configuration; and[0038]
• FIG. 7C is a schematic view of a pigtail shaped coil configuration.[0039]
DESCRIPTION
• Embodiments of the present invention are described below. The invention is not limited to these embodiments, and various modifications to the disclosed embodiments are also encompassed by the invention. A medical device according to the invention can be used to entrain biological and/or foreign material during a medical procedure. The medical procedure can involve the fragmentation of the material. The device can also be used to remove the material and/or fragments of the material safely from the body. In addition, the device can be used as a self-anchoring guide wire.[0040]
• FIGS. 1A and 1B depict a[0041]medical device100 in accordance with the invention in two different configurations. Themedical device100 includes anelongate sleeve104 and anelongate core102. Thesleeve104 includes alumen106 that extends longitudinally within at least a portion of thesleeve104, adistal end112, and aproximal end114. In one embodiment the sleeve includes anouter wall103 and aninner wall105. Thecore102 is adapted to be disposed within thelumen106 of thesleeve104. At least aportion110 of thesleeve104 is adapted to form a plurality ofcoils108 disposed in a conical shape when thecore102 is removed from a section of thelumen106 that extends through the plurality of coils108 (FIG.1A). The plurality ofcoils108 are straightened and thesleeve104 assumes a substantially linear configuration when thecore102 is inserted within the section of thelumen106 extending through the plurality of coils108 (FIG. 1B). Theproximal end118 of the plurality ofcoils108 is located apredetermined distance116 from theproximal end114 of the sleeve. Themedical device100 is configured to support the treatment and/or removal of foreign objects and organic material, e.g., blood clots, tissue, and biological obstructions, such as urinary, biliary, and pancreatic stones, from an anatomical lumen.
• The[0042]sleeve104 is constructed, at least in part, of a shape-memory material that enables thesleeve104 to assume a coiled configuration forming a conical shape when thecore102 is removed from the section of thelumen106 extending through the plurality ofcoils108. The shape-memory material of thesleeve106 also enables the plurality ofcoils108 to assume a substantially linear configuration when thecore102 is extended through the section of thelumen106 extending through the plurality ofcoils108, as shown in FIG. 1B, without significantly affecting the ability of thesleeve104 to revert back into the coiled configuration when thecore102 is removed from the section of thelumen106 extending through the plurality ofcoils108.
• Shape-memory materials suitable for use in forming the[0043]sleeve104 include plastics, stainless steel, and metallic alloys of nickel, titanium, cooper, cobalt, vanadium, chromium, and iron. In one embodiment, the shape-memory material forming thesleeve104 is a superelastic material, such as nitinol, which is a nickel-titanium alloy. Thecore102 can also be made from a shape-memory material, such as nitinol. Other suitable materials for the manufacture of the sleeve or the core include: thermoplastic polyurethane (TPU), thermoplastic polyester elastomers, nylons, and equivalent materials. Additional suitable materials will be apparent to those skilled in the art.
• FIG. 1C is a cross-sectional view of the[0044]medical device100 of FIGS. 1A and 1B. In the embodiment shown, themedical device100 has a generally circular cross-section; however, the cross-section could be polygonal, arcuate, or combinations of arcuate and polygonal elements. FIG. 1C depicts the core102 disposed within thelumen106 of thesleeve104. In one embodiment, the sleeve includes anouter wall103 and aninner wall105.
• FIGS.[0045]2A-2C depict amedical device100, positioned within ananatomical lumen124 of a patient. The plurality of coils serve as a physical barrier or backstop during the lithotripsy procedure to ensure that the smaller fragments do not migrate in an undesired direction, e.g., back toward the kidney. The instrumentation used to perform the lithotripsy can be introduced into the desired location adjacent to the obstruction via another catheter or guide wire.
• In one aspect, a health care practitioner inserts the[0046]medical device100 within ananatomical lumen124, such as a ureteral passage, to ensnare fragments of stones resulting from a lithotripsy procedure or other objects obstructing the lumen. In this aspect, the plurality ofcoils108 is deployed into a conical shape within theanatomical lumen124 by retracting the core102 from within thelumen106 of thesleeve104, as depicted in FIG. 2B. Themedical device100 can be inserted into ananatomical lumen124 of a patient via a catheter or a guide wire. In one method of use of themedical device100, a health care practitioner inserts themedical device100 into ananatomical lumen124 with thesleeve104 in a substantially linear configuration and thecore102 extended through the section of thelumen106 that extends through the plurality ofcoils108, as shown in FIG. 2A. For example, in a lithotripsy procedure to remove a kidney stone from a patient's ureter, themedical device100 is introduced into the patient's urinary passage until thedistal end112 passes beyond the location of thestone126 lodged in the ureter. The health care practitioner then deploys the plurality ofcoils108 downstream of thestone126 by retracting the core102 from the section of thelumen106 extending through the plurality ofcoils108, as depicted in FIG. 2B. The plurality ofcoils108 act as a backstop to prevent the migration of the fragments, as shown in FIG. 2B. The maximum outsidediameter120 of the plurality ofcoils108 is designed to be substantially the same as or slightly greater than the inside diameter of theanatomical lumen124 so that the passage will be sufficiently occluded to prevent any subsequent migration of thekidney stone126.
• Once the lithotripsy procedure is complete, the health care practitioner can extend the[0047]core102 through the section of thelumen106 that extends through the plurality ofcoils108 in order to straighten, reposition and redeploy the plurality of coils to ensnare the fragments, as shown in FIG. 2C. If the fragments are small enough to pass through the anatomical lumen, the health care practitioner can drag the fragments from the anatomical lumen and out of the body. If, however, the fragments of the stone are still too large to pass through sections of the anatomical lumen, thesleeve104 can be straightened by extending thecore102 through the section of thelumen106 that extends through the plurality ofcoils108. In this scenario, the health care practitioner can repeat the treatment procedure by repositioning and redeploying the plurality ofcoils108 beyond thestone126 and performing a second lithotripsy procedure to further fragment the remaining obstructions.
• FIG. 3A is a depiction of another[0048]medical device200 in accordance with the invention. Thesleeve104 can include a plurality of coiled configurations, for example, a first plurality ofcoils108 and a second plurality ofcoils202. In one embodiment, the second plurality ofcoils202 is located distally to the first plurality ofcoils108 and formed in aportion210 of thesleeve104. Each plurality of coils could form a variety of shapes, such as conical, spherical, helical, frusto-conical or combinations thereof. As discussed above with respect to the first plurality ofcoils108, the second plurality ofcoils202 also forms a shape when thecore102 is removed from a section of thelumen106 extending through the second plurality ofcoils202 and assumes a substantiallylinear configuration210 when thecore102 is extended through the section of thelumen106 that extends through the second plurality ofcoils202.
• FIG. 3B depicts the[0049]sleeve104 in a substantially linear configuration, where thecore102 has been extended through the section of thelumen106 that extends through the plurality ofcoils108 and the section of thelumen106 that extends through the second plurality ofcoils202. A device including two separate pluralities of coils is especially useful for the removal of two separate obstructions lodged within an anatomical lumen at the same time. A health care practitioner can insert the medical device inside a patient in a substantially linear configuration, shown in FIG. 3B, with thedistal end112 of the medical device beyond an obstruction distal to an obstruction proximal to thedistal end112 of the medical device. The health care practitioner can subsequently withdraw the core102 from thelumen106 of the sleeve, resulting first in the deployment of the second plurality ofcoils202 encasing the distal obstruction followed by the deployment of the first plurality ofcoils108 that would capture the proximal obstruction. This way, the health care practitioner uses themedical device200 to sweep both obstructions out of the patient's body, without having to redeploy the device.
• FIG. 4A is another[0050]medical device300 in accordance with the invention, where anexternal surface302 of thesleeve104 is covered by a polymeric material orsheath304. Thepolymeric material304 can be spray coated onto theexternal surface302 of thesleeve104. Alternatively, apolymer sheath304 can be heat-shrunk onto theexternal surface302 of thesleeve104. Thepolymeric sheath304 can cover the entire length of thesleeve104 or only a portion or portions of thesleeve104, such as the portions including the plurality ofcoils108 and/or the coiled element202 (110 and210 respectively). Thecoiled element202 can be covered by thesame polymeric sheath304 as the plurality ofcoils108 or thecoiled element202 can be covered by adifferent polymeric sheath304. Thecoiled element202 can also be covered with apolymeric sheath304 that has a different color or other different properties than that of thepolymeric sheath304 that covers the plurality ofcoils108.
• The[0051]polymeric sheath304 can reduce the amount of friction between the turns of the plurality ofcoils108 and an inner lining of an anatomical lumen or a catheter used for delivering themedical device300, thereby decreasing the risk of damage to the surrounding area. Thepolymeric sheath304 can be made of silicone, a flouroploymer, such as polytetraflouroethylene (PTFE), expanded polytetraflouroethylene (ePTFE), ethylene-tetrafluoroethylene (ETFE), or other suitable materials that exhibit laser resistant characteristics, e.g., a light color, that prevent or minimize damage to thesleeve104 or other elements of themedical device300 during a lithotripsy procedure.
• In one embodiment, the color of the[0052]polymeric sheath304 surrounding the plurality ofcoils108 differs from the color of other portions of thepolymeric sheath304 and/or from the color of other elements of themedical device300 in order to assist a health care practitioner in determining the location of the plurality ofcoils108 within the anatomical lumen during a lithotripsy procedure. In another embodiment, thepolymeric sheath304 preferably comprises a plurality of colors along a length of thesleeve104 to assist the health care practitioner who is performing the lithotripsy procedure to detect movement in thesleeve104 and to gauge distances. This enables the health care practitioner to track and maneuver thesleeve104 during various phases of the lithotripsy procedure. In one embodiment, thepolymeric sheath304 exhibits the standard color of a PTFE heat shrunk extrusion with a colored stripe along the length of thesleeve104. As themedical device300 is manipulated, the relative size and distances of the wound sections of the plurality ofcoils108 can be readily determined by examining the spiral configuration of the colored stripe, which appears about the wound section of the plurality ofcoils108. The stripe color is also preferably selected to be resistant to and reflect laser energy so as to minimize damage to thepolymeric sheath304.
• In another embodiment, the[0053]sleeve104 can be covered with a radio-opaque material that enables a health care practitioner to track themedical device300 inside a patient under an X-ray machine. In another embodiment, the plurality ofcoils108 are covered with a radio-opaque material, which enables a health care practitioner to track and maneuver the configuration of thesleeve104 from a coiled configuration to a substantially linear configuration, as and when needed during a lithotripsy procedure.
• FIG. 4B is a cross-sectional view of the[0054]medical device300 shown in FIG. 4A. In one embodiment, themedical device300 has a generally circular cross-section with a core102 disposed in thelumen106 of thesleeve104 and apolymeric coating304 on theexternal surface302 of thesleeve104. In various embodiments, themedical device300 can have a cross-section, such as polygonal, arcuate, or combinations of arcuate and polygonal elements.
• FIG. 5A depicts a[0055]sleeve104 for use with a medical device in accordance with the invention. Thesleeve104 includes at least oneflexible portion404 and one or morerigid portions402,406. In the embodiment shown in FIG. 5A, thesleeve104 includes arigid portion402,406 on each side of theflexible portion404. The flexibility and rigidity in different portions of thesleeve104 can result either from theflexible portion404 and morerigid portions402,406 having different wall thicknesses (t₁, t₂) or they can be made from different materials that make portions of the sleeve flexible or more rigid. In one embodiment, theflexible portion404 can be an expandable balloon. In the embodiment depicted in FIG. 5A, the wall of theflexible portion404 has a thickness (t₁) substantially less than the thickness (t₂) of the walls of therigid portions402,406 of thesleeve104. Theflexible portion404 of thesleeve104 changes form from an unexpanded state, i.e., the initial diameter of the sleeve, to an expanded state, i.e., a state of increased diameter. Alternatively, theflexible portion404 can be sufficiently pliable to conform to the actual coil shape.
• FIG. 5B depicts a[0056]core102 for use with a medical device in accordance with the invention. Thecore102 includes a section that is flexible, referred to as a shape-changingsection410, and is adapted to change shape when extended through thelumen106 of thesleeve104. In one embodiment, the shape-changingsection410 of thecore102 has a coiledconfiguration408 when unrestrained. The shape-changingsection410 of the core102 can retain a substantially linear configuration when inserted within thelumen106 of thesleeve104. Thecoiled configuration408 of the core can include one coil or a plurality of coils resulting in a shape, such as pigtail, conical, spherical, helical, frusto-conical, or combinations thereof.
• The[0057]core102 and thesleeve104 can be made from the same material or different materials. In one embodiment, the core includes a shape-memory material. In another embodiment, the sleeve includes a shape-memory material. The shape-changingsection410 of thecore102 is made from a shape-memory material, which enables reversible change in the shape-changingsection410 from acoiled configuration408 to a substantially linear configuration420 (FIG. 5C). Theflexible portion404 of the sleeve can also be made of a shape-memory material that enables the outer diameter of theflexible portion404 to expand when the shape-changingsection410 of thecore102 reaches theflexible portion404 and forms the coiledconfiguration408.
• FIG. 5C depicts a[0058]medical device400 including theelongate sleeve104 of FIG. 5A and theelongate core102 of FIG. 5B. Thecore102 is inserted into thelumen106 of thesleeve104 such that the shape-changingsection410 of thecore102 is retained in the substantiallylinear configuration420 within therigid portion402 of thesleeve104.
• In the embodiment shown in FIG. 5D, the shape-changing[0059]section410 of the core102 forms acoiled configuration408 when the shape-changingsection410 of the core reaches theflexible portion404 of thesleeve104. The outer diameter of theflexible portion404 of the sleeve increases to accommodate the coiledconfiguration408 of thecore102. The more rigid portions of thesleeve402,406 retain the other portions of the core102 in a substantially linear configuration. Therefore, the reversible transformation of the shape-changingsection410 enables the core102 to assume acoiled configuration408 when the shape-changingsection410 parallels theflexible portion404 and to be retained in the substantiallylinear configuration420 when the shape-changingsection410 of thecore102 is retracted from theflexible portion404 of thesleeve104 to encounter the morerigid portions402,406 of thesleeve104. In this manner, the shape-changingsection410 of the core and theflexible portion404 of thesleeve104 can change configurations depending on whether the shape-changingsection410 of thecore102 is retracted or extended through the section of thelumen106 that extends through theflexible portion404 of thesleeve104.
• In yet another embodiment and as shown in FIG. 5E,[0060]flexible portion404 of thesleeve104 conforms to the shape of the shape-changing section of thecore410 when the shape-changing section of thecore410 reaches theflexible portion404 of the sleeve. In this embodiment, theflexible portion404 of the sleeve overlays the shape formed by the shape-changing section of thecore410, so as to adopt the identical configuration as that of thecore102. Theflexible portion404 of thesleeve104 reverts back to a substantially linear configuration when thecore102 is retracted from within thelumen106 of the sleeve.
• A variety of conventional techniques can be used for the manufacture of the[0061]sleeve104 including flexible and more rigid portions. In one embodiment, theflexible portion404 and the morerigid portions402 and406 of thesleeve104 can be manufactured separately and subsequently joined or sealed in an end-to-end or overlapping fashion in order to generate asingle sleeve104. The flexible and more rigid portions of thesleeve104 can be joined by a number of means known in the art, including heat fusing, adhesive bonding, chemical bonding or mechanical attachment. In one embodiment, the flexible and more rigid portions of the sleeve are hermetically sealed. The flexible portion of thesleeve404 can be made from a suitable polymeric material, such as ethylene vinyl acetate, which becomes more pliable upon irradiation.
• FIGS.[0062]6A-6C are depictions of anothermedical device500 in accordance with the invention, where both thecore102 and thesleeve104 include shape-changingsections502,504 that can form coiledconfigurations506,508. Thesleeve104 includes alumen106 that extends within at least a portion of thesleeve104 and thecore102 is slidably disposable within thelumen106 of thesleeve104. FIG. 6A is a depiction of themedical device500, where thesleeve104 and thecore102 are unrestrained, e.g., pulled apart from each other, and both shape-changingsections502,504 are in theircoiled configurations506,508. In this embodiment, thecore102 is retracted from thelumen106 of thesleeve104.
• In FIG. 6B, the shape-changing[0063]section504 of thesleeve104 assumes a substantially linear configuration when restrained, e.g., when a section of thecore102 other than the shape-changingsection502 is extended through a section of thelumen106 that extends through the shape-changingsection504 of thesleeve104. Similarly, the shape-changingsection502 of thecore102 assumes a substantially linear configuration when restrained, e.g., the core is inserted into a section of thesleeve104 other than the shape-changingsection504.
• In FIG. 6C, the shape-changing[0064]sections502,504 are aligned such that both assume theircoiled configurations506,508. In one embodiment, the shape-changingsections502,504 can include a plurality of coils configured in a shape, such as conical, spherical, helical, frusto-conical, or combinations thereof. In one embodiment, the shape-changingsections502,504 are adapted to assume at least partially theircoiled configurations506,508 when only partially aligned. Alternatively, the shape-changingsections502,504 can be adapted to retain their substantiallylinear configuration510,512 when only partially misaligned. In one embodiment, the coil configurations of the sleeve section and the core section are equal in size and shape. For example, the sleeve section coil configuration can include eight coils in a conical shape and the core section coil configuration can include eight coils in a complimentary conical shape.
• FIGS.[0065]7A-7C depict examples of different coil shapes that may be formed in thecore102, thesleeve104, or both. FIG. 7A is a depiction of aspherical shape604 formed by the plurality of coils. FIG. 7B is a depiction of ahelical shape606 formed by the plurality of coils. In FIG. 7C, the shape is a single coil in a pigtail configuration, instead of a plurality of coils, as shown in FIGS. 7A and 7B. The shape and size of the coil configuration is selected based on the intended use of the medical device.
• In all the foregoing aspects of the invention, the overall length of the medical device depends on the application for which the medical device is intended. Generally, the overall length will be in the range of about 50 cm to about 250 cm. In one embodiment and with respect to urinary applications, the total length of the[0066]device100 is about 140 cm to about 220 cm, and preferably about 200 cm. Devices for other applications, or those intended for use with children, will be different lengths.
• The diameters of the[0067]sleeve104 and thecore102 depend on the application for which the device is intended. For example, in the case of urinary applications, the maximum outside diameter of thesleeve104 is typically in the range of about 0.5 mm to about 1.5 mm and the maximum diameter of thecore102 is such as to enable thecore102 to be slidably disposed within thelumen106 of thesleeve104. For other applications, for example, use of the device for the removal of an obstruction in the gastrointestinal tract, the outside diameter of thesleeve104 can be as large as about 1 cm to about 2 cm.
• In all the forgoing aspects of the medical device of the invention, the number of coils in plurality of coils of the sleeve and the core depends on the intended use of the medical device. In one embodiment, the plurality of coils has between about 5 turns and about 15 turns, and preferably about 7 turns to about 10 turns. The maximum outside diameter of the proximal end of the plurality of coils can be, for example, in the range of about 0.2 cm to about 3.0 cm, and preferably about 0.7 cm to about 0.8 cm. Adjacent turns of the plurality of coils may abut each other or be separated by[0068]small gaps122. In the embodiment shown in FIG. 1A, thegaps122 are up to about 2 mm wide; however, the gaps can be varied to suit a particular application.
• The location of the plurality of coils also depends on the intended use of the medical device. In one embodiment, the[0069]distance116 of the coils from the proximal end of the device is about 0.0 cm to about 15.0 cm. In another embodiment, thedistance116 can be about 50 cm to about 200 cm, or about 100 cm to about 130 cm and preferably about 120 cm to about 130 cm.
• In all the forgoing aspects of the medical device of the invention, the[0070]sleeve104 andcore102 can be manufactured by, for example, injection molding or extrusion and optionally a combination of subsequent machining operations. Extrusion processes may be used to provide a uniform shape, such as a single monolithic frame. Injection molding can then be used to provide the desired geometry of the open spaces, or the open spaces could be created in the desired locations by a subsequent machining operation. In one embodiment, thesleeve104, thecore102, or both can be made from a co-extrusion high density polyethylene for an inner portion and a polyamide for the outer portion. The co-extrusion process results in the necessary combination of flexibility, to navigate tortuous vessels, and column strength to effectively straighten out the coil. In addition, the coextrusion process can be used to produce thesleeve104 andpolymeric coating304. Alternatively, thecore102 could be drawn wire.
• In all the foregoing aspects of the invention, the shapes of the sleeve and the core can be generated by wrapping the desired portions of the sleeve or the core around a mandrel to form into the desired shape and then heating at sufficient time and temperature to set the shape into the sleeve, the core, or both. The time or the temperature largely depends on the type of material that is used for the manufacture of the sleeve and the core. Once the portions of the sleeve or the core have been heat-treated to set into the desired configurations, the sleeve or the core may be straightened by pulling at the linear portions on either side of the shape; however, the sleeve and the core will return to the wound configurations when released.[0071]
• Other embodiments incorporating the concepts disclosed herein are within the spirit and scope of the invention. The described embodiments are illustrative of the invention and not restrictive.[0072]

Claims (32)

What is claimed is:

1. A medical device comprising:

an elongate core; and

an elongate sleeve defining a lumen extending longitudinally within at least a portion of the elongate sleeve, the sleeve including a plurality of coils disposed in a conical shape when the core is removed from a section of the lumen extending through the plurality of coils, the coils being straightened and the sleeve being in a substantially linear configuration when the core is inserted within the section of the lumen extending through the plurality of coils.

2. The medical device ofclaim 1, wherein the sleeve comprises a shape-memory material.

3. The medical device ofclaim 1, wherein the sleeve and the core comprise different materials.

4. The medical device ofclaim 1, wherein the sleeve further comprises at least one coiled element disposed in a portion of the sleeve distal to the plurality of coils, the at least one coiled element formed when the core is removed from a section of the lumen extending through the at least one coiled element and being in a substantially linear configuration when the core is inserted into the section of the lumen extending through the at least one coiled element.

5. The medical device according toclaim 1, wherein each of the sleeve and core has a cross-section selected from the group consisting of polygonal, arcuate, and combinations of arcuate and polygonal elements.

6. The medical device ofclaim 1, wherein the sleeve includes a coating disposed on an external surface of the sleeve.

7. The medical device ofclaim 6, wherein the coating comprises a polymeric material.

8. The medical device ofclaim 7, wherein the polymeric material is selected from the group consisting of polytetraflouroethylene, expanded polytetraflouroethylene, ethylene-tetrafluoroethylene, and silicone.

9. A medical device comprising:

an elongate sleeve defining a lumen extending longitudinally within at least a portion of the elongate sleeve, the sleeve comprising a first portion and a second portion more rigid than the first portion; and

an elongate core slidably disposable within the lumen, the core including a section that changes shape when disposed in the first portion to increase an outer diameter of the sleeve, the section being retained in a substantially linear configuration when disposed in the second portion.

10. The medical device ofclaim 9, wherein the core comprises a shape-memory material.

11. The medical device ofclaim 9, wherein the sleeve comprises a shape-memory material.

12. The medical device ofclaim 9, wherein the first portion comprises an expandable balloon.

13. The medical device ofclaim 9, wherein the section that changes shape forms a coiled configuration when disposed in the first portion.

14. The medical device ofclaim 13, wherein the coiled configuration comprises a plurality of coils.

15. The medical device ofclaim 14, wherein the plurality of coils form a shape selected from the group consisting of conical, spherical, helical, frusto-conical, and combinations thereof.

16. The medical device ofclaim 9, wherein the first and second portions comprise walls, wherein a thickness of the first portion wall is substantially less than a thickness of the second portion wall.

17. The medical device ofclaim 9, wherein the first portion and the second portion comprise different materials.

18. The medical device ofclaim 9, wherein the sleeve includes a coating disposed on an external surface of the sleeve.

19. The medical device ofclaim 18, wherein the coating comprises a polymeric material.

20. The medical device ofclaim 19, wherein the polymeric material is selected from the group consisting of polytetraflouroethylene, expanded polytetraflouroethylene, ethylene-tetrafluoroethylene, and silicone.

21. The medical device according toclaim 9, wherein each of the sleeve and core has a cross-section selected from the group consisting of polygonal, arcuate, and combinations of arcuate and polygonal elements.

22. A medical device comprising:

an elongate sleeve defining a lumen extending longitudinally within at least a portion of the elongate sleeve, the sleeve including a sleeve section that changes shape; and

an elongate core slidably disposable within the lumen, the core including a core section that changes shape, each of the sleeve and core sections retaining a substantially linear configuration when restrained and forming a substantially coiled configuration when aligned.

23. The medical device ofclaim 22, wherein the sleeve comprises a shape-memory material.

24. The medical device ofclaim 22, wherein the core comprises a shape-memory material.

25. The medical device ofclaim 22, wherein the coiled configuration comprises a plurality of coils.

26. The medical device ofclaim 25, wherein the plurality of coils form a shape selected from the group consisting of conical, spherical, helical, frusto-conical, and combinations thereof.

27. The medical device ofclaim 22, wherein each of the sleeve and core sections forms the substantially coiled configuration when partially aligned.

28. The medical device ofclaim 22, wherein each of the sleeve section and core section retains the substantially linear configuration when at least partially misaligned.

29. The medical device ofclaim 22, wherein the sleeve includes a coating disposed on an external surface of the sleeve.

30. The medical device ofclaim 29, wherein the coating comprises a polymeric material.

31. The medical device ofclaim 30, wherein the polymeric material is selected from the group consisting of polytetraflouroethylene, expanded polytetraflouroethylene, ethylene-tetrafluoroethylene, and silicone.

32. The medical device according toclaim 22, wherein each of the sleeve and core has a cross-section selected from the group consisting of polygonal, arcuate, and combinations of arcuate and polygonal elements.

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