US20040193178A1 - Multiple joint implant delivery systems for sequentially-controlled implant deployment - Google Patents

Abstract

The invention provides an atraumatic, low profile device for the delivery of one or more implants into tubular organs or open regions of the body. The implant delivery device may simultaneously or independently release portions of the implant, e.g., the proximal and distal ends of the implant. This independent release feature allows better implant positioning at the target site. Upon deployment, the implants may be placed at the target site without a sheath.

Description

FIELD OF THE INVENTION
• This invention relates to devices and methods for placing one or more implants such as helical scaffolds or occlusive members into tubular organs or open regions of the body. The implants may be of types that maintain patency of an open anatomical structure, occlude a selected volume, isolate a region, or collect other occlusive members at a site. Included in the description are devices and methods for deploying the various implants, typically without a sheath, in a serial fashion, and with high adjustibility.[0001]
BACKGROUND OF THE INVENTION
• Implants such as stents and occlusive coils have been used in patients for a wide variety of reasons. For instance, stents are often used to treat arterial stenosis secondary to atherosclerosis. Various stent designs have been developed and used clinically, but self-expandable and balloon-expandable stent systems and their related deployment techniques are now predominant. Examples of self-expandable stents currently in use are WALLSTENT® stents (Schneider Peripheral Division, Minneapolis, Minn.) and Gianturco stents (Cook, Inc., Bloomington, Ind.). The most commonly used balloon-expandable stent is the PALMAZ® stent (Cordis Corporation, Warren, N.J.).[0002]
• Typically, after balloon angioplasty has been performed, either a self-expandable or balloon-expandable stent is advanced over a guidewire and positioned at the target site. A protective sheath or membrane is then retracted proximally to allow expansion of a self-expanding stent. Alternatively, a delivery balloon may be inflated, thereby expanding the stent.[0003]
• Despite improvements in delivery systems, balloon design, and stent design, these over-the-guidewire and/or sheathed self-expanding stent deployment systems still have their limitations. For instance, sheathed stents tend to move forward when the sheath is pulled back, deploying them imprecisely. The sheathed design also requires that the stent delivery system be larger in diameter and less flexible. Furthermore, for sheathed systems, the interventional procedure may only proceed if the vessel of interest is of sufficiently large diameter to allow sheath placement to avoid significant damage to the luminal surface of the vessel. Moreover, balloon-expandable stents, by virtue of a large diameter and relative inflexibility, are often unable to reach distal vasculature. For both self-expandable and balloon-expandable stent deployment systems, repositioning or step-wise release of the stent are usually not available features. Similarly, occlusive coil placement systems such as systems that deliver detachable platinum coils and GDC® coils also generally do not contain repositionable or step-wise release features.[0004]
• Consequently, a smaller diameter (lower profile), repositionable implant deployment device that releases an implant into, or upon, a body region in a more precise, continuous or step-wise fashion, without the use of a sheath or balloon would provide significant benefit to patients with various medical conditions.[0005]
SUMMARY OF THE INVENTION
• The present invention is a low profile implant delivery device that may be deployed without a sheath, and is designed to release portions of implants simultaneously or sequentially.[0006]
• In one variation, the implant delivery device includes a noninflatable, elongate delivery guide member having a distal end and configuration that allows it to direct at least one implant having an exterior and interior surface to an anatomical treatment site by manipulation by a user. The at least one implant has a delivery diameter prior to its release, is located proximally of the distal end of the delivery guide member prior to release, and has at least one releasable joint configured to maintain at least a section of the at least one implant at the delivery diameter until release of the at least one releasable joint. The delivery guide member sections that are proximal and distal to the at least one implant also have delivery diameters. These guide member delivery diameters may be substantially equal to the at least one implant delivery diameter prior to implant release.[0007]
• The implant may be a helical scaffold, e.g., a stent, in particular, a self-expandable stent, or it may be an occlusive coil. The implant may be symmetric or asymmetric. In some instances, the implant delivers a therapeutic agent.[0008]
• The delivery guide member may include a wire and/or a tubular member having a lumen. If desired, a radioopaque marker may be included on the delivery guide to aid with its placement. When designed to include a tubular member, it co-axially surrounds at least a portion of the delivery guide, and works as a tubular actuator configured to release at least one releasable joint upon distal axial movement along the delivery guide member.[0009]
• In another variation, the implant delivery device includes an actuator slidably located at least partially within the delivery guide member and is configured to mechanically release at least one releasable joint upon axial movement of the actuator within the delivery guide member. In other variations, the actuator may also release at least one releasable joint upon rotational movement of the actuator, upon the application of fluid pressure in the delivery guide member lumen, or upon application of a suitable DC current to the at least one releasable joint. Release of the releasable joints using any one of the release mechanisms described above may be sequential, if precise positioning is required, or may be simultaneous. Each feature of each variation may be used on any of the other variations.[0010]
• The implant delivery device may be included in a system for implant delivery which further employs one or more embolic filters at either the proximal or distal section of the delivery guide, or at both the proximal and distal sections of the delivery guide.[0011]
• The system may be used for implant delivery into lumens of tubular organs including, but not limited to, blood vessels (including intracranial vessels, large vessels, peripheral vessels, adjacent aneurysms, arteriovenous malformations, arteriovenous fistulas), ureters, bile ducts, fallopian tubes, cardiac chambers, ducts such as bile ducts and mammary ducts, large and small airways, and hollow organs, e.g., stomach, intestines, and bladder. The implant may be of a design that is of a size that is smaller during delivery and larger after implantation. The design may be used to provide or to maintain patency in an open region of an anatomical structure, or to occlude a site, or to isolate a region (e.g., to close an aneurysm by blocking the aneurysm opening or neck by placement in an adjacent anatomical structure such as an artery or gastrointesinal tubular member), or to corral or collect a number of occlusive devices (e.g., coils or hydratable polymeric noodles) or compositions at a site to be occluded or supported. In another variation, the implant is located in a gap between proximal and distal sections of the delivery guide member. The system may also be employed for implant delivery into solid organs or tissues including, but not limited to, skin, muscle, fat, brain, liver, kidneys, spleen, and benign and malignant tumors. Preferably, the implant is delivered to a target site in a blood vessel lumen.[0012]
• In a general aspect, the system is a guidewire-less implant delivery system that includes a noninflatable, elongate delivery guide member having a proximal end and a distal end. The guide member is configured to direct at least one implant having an exterior and interior surface to an anatomical treatment site by manipulation by a user. The at least one implant has a delivery diameter prior to release of the at least one implant and is located proximally of the distal end of the delivery guide member prior to release. The at least one releasable joint is configured to maintain at least a section of the at least one implant at the delivery diameter until release of the at least one releasable joint. The guidewire-less system also has a flexibility and remote directability such that a user may direct the distal end of the guide member into, and introduce, the at least one implant into a coronary artery solely by manipulation of the delivery guide member from its proximal end.[0013]
BRIEF DESCRIPTION OF THE DRAWING(S)
• FIG. 1A is a side view of an implant delivery device with a partial cross-section of the distal section of the delivery guide.[0014]
• FIG. 1B is a cross-sectional view of the delivery guide and implant taken at line[0015]1B-1B in FIG. 1A.
• FIG. 2 is a side view of an implant delivery device having a tubular member (actuator) attached to the proximal implant end with a partial cross-section of the distal section of the delivery guide.[0016]
• FIG. 3A is a side:view of the implant in FIG. 2 being expanded by distally moving the tubular member towards the distal section of the delivery guide.[0017]
• FIG. 3B is a longitudinal cross-sectional view of a distal implant release mechanism.[0018]
• FIGS. 3C[0019]₁and3C₂are longitudinal cross-sectional views of an implant delivery device having a mechanical release mechanism for deploying one end of an implant.
• FIGS. 3D[0020]₁-3D₃are longitudinal cross-sectional views of an implant delivery device having a mechanical release mechanism for independently releasing the implant ends.
• FIGS. 3E[0021]₁-3E₄are longitudinal cross-sectional views of an implant delivery device having a hydraulic release mechanism for independently releasing the implant ends.
• FIGS. 3F[0022]₁-3F₂are longitudinal cross-sectional views of a variation of the hydraulic release mechanism described in3E₁-3E₄.
• FIGS. 3G[0023]₁-3G₃are longitudinal cross-sectional views of an implant delivery device having a mechanical release mechanism according to another variation of the invention.
• FIG. 4 is a longitudinal cross-sectional view of an implant delivery device having a mechanical release mechanism according to yet another variation of the invention.[0024]
• FIGS. 5A-5C are longitudinal cross-sectional views of an implant delivery device having an electrolytic implant release mechanism.[0025]
• FIG. 5D shows a longitudinal cross-sectional view of an implant delivery device having an electrolytic release mechanism according to another variation of the invention.[0026]
• FIG. 5E shows a longitudinal cross-sectional view of an implant delivery device having a thermal release mechanism according to one variation of the invention.[0027]
• FIGS. 6A-6D show the general method for serially releasing an implant at a target site.[0028]
DETAILED DESCRIPTION OF THE INVENTION
• Described here are devices, systems, and methods for delivering implants into both open and solid regions of the body. The term “region” as used herein refers to luminal structures as well as solid organs and solid tissues of the body, whether in their diseased or nondiseased state. Examples of luminal structures include, but are not limited to, blood vessels, arteriovenous malformations, aneurysms, arteriovenous fistulas, cardiac chambers, ducts such as bile ducts and mammary ducts, fallopian tubes, ureters, large and small airways, and hollow organs, e.g., stomach, intestines, and bladder. Solid organs or tissues include, but are not limited to, skin, muscle, fat, brain, liver, kidneys, spleen, and benign and malignant tumors.[0029]
• The device assembly generally includes an elongate, perhaps solid delivery guide, an implant, and one or more implant release mechanisms. Guidewire-less systems are used to deliver the one or more implants. By “guidewire-less” it is meant that the system does not require a guiding device of a diameter less than that of the guide member upon which the implant is delivered to reach a chosen implantation site. Instead, the guidewire-less system is flexible and remotely directable, the remote directability being such that a user may direct the distal end of the guide member into, and introduce, the at least one implant into a coronary artery solely by manipulation of the delivery guide member from its proximal end.[0030]
Delivery Guide or Delivery Guide Member
• The delivery guide is elongate and has a comparatively small effective diameter. It has the function of permitting delivery of the implant to a selected site and supporting the implant in a collapsed form during positioning and implantation. The delivery guide is usually noninflatable. It may also be solid, or may have a lumen extending therethrough, depending on such factors as the degree of flexibility required, type of associated release mechanism, the constitution material, and the like. The tip of the delivery guide may be tapered and/or straight, curved, or j-shaped, depending on factors such as physician preference, the anatomy of the tubular organ or region of interest, degree of stiffness required, and the like. The delivery guide may or may not include an outer spring coil, for, e.g., fluoroscopic visualization.[0031]
• The delivery guide member and the delivery system into which it is placed desirably serves the function as would a guidewire in, for instance, a cardiac or neurovascular catheterization procedure. The concept that the delivery guide member or system including that guide member and implant(s) is “remotely directable” is to say that the combination of physical parameters of the delivery guide member, implant, and joints are selected to allow advancement of the system much in the same way as would be a guidewire. Such physical parameters include, for instance, choice of materials, stiffness, size of materials, physical or chemical treatment, tapering (if desired), all in the same way that those physical parameters are selected in designing a cardiovascular or neurovascular guidewire.[0032]
• The delivery guide may be made from any biocompatible material including, but not limited to, stainless steel and any of its alloys; titanium alloys, e.g., nickel-titanium alloys; other shape memory alloys; tantalum; polymers, e.g., polyethylene and copolymers thereof, polyethylene terephthalate or copolymers thereof, nylon, silicone, polyurethanes, fluoropolymers, poly (vinylchloride), and combinations thereof. The diameter of the delivery guide may usually be about 0.013 cm to about 0.130 cm (about 0.005 inches to about 0.05 inches), more usually about 0.013 cm to about 0.076 cm (about 0.005 inches to about 0.03 inches), and more usually still about 0.015 cm to about 0.030 cm (about 0.006 inches to about 0.012 inches). In a preferred variation, the diameter of the delivery guide is approximately about 0.020 cm (about 0.008 inches).[0033]
• A lubricious coating may be placed on the delivery guide if desired to facilitate advancement of the delivery guide. The lubricious coating typically will include hydrophilic polymers such as polyvinylpyrrolidone-based compositions, fluoropolymers such as tetrafluoroethylene, or silicones. In one variation, the lubricious coating may constitute a hydrophilic gel. Furthermore, the delivery guide may include one or more radioopaque markers that indicates the location of the distal section of the delivery guide upon radiographic imaging. Usually, the marker will be detected by fluoroscopy.[0034]
Implants
• The implant itself may be of a shape tailored to achieve a specific purpose. As noted elsewhere, if the purpose of the implant is to provide or to maintain patency of an anatomical structure such as an artery or duct, the implant shape after implantation is itself tubular. The shape may be symmetric or asymmetric, as the purpose dictates.[0035]
• Other shapes, including cage structures, may be used to provide patency to vessels or to act as collecting or coralling structures for occlusive members or materials.[0036]
• If the purpose or task is to occlude a lumen or open region, the implant may have the form of an occlusive coil that remains helical after deployment or assumes a random orientation.[0037]
• In one variation, the implant for placement into a luminal structure is a helical scaffold, e.g., a stent, but any scaffold shape that maintains patency of a lumen may be used. The stents are typically self-expanding stents, such as described in U.S. Pat. No. 4,768,507 to Fishell et al., U.S. Pat. No. 4,990,155 to Wilkoffet al., and U.S. Pat. No. 4,553,545 to Maass et al. In another variation, the implant is an occlusive member, e.g., an occlusive coil, such as described in U.S. Pat. No. 5,334,210 to Gianturco and U.S. Pat. No. 5,382,259 to Phelps et al.[0038]
• The interior and exterior surfaces of the implant may be designed to prevent the activation of pathological processes during or after implant deployment. For example, in the case of a vascular stent, the exterior stent surface may be formed to be smooth to decrease the likelihood of intimal damage upon stent release (which would trigger the inflammatory process and attract atheromatous plaque-forming cells). The interior stent surface may also be smooth to minimize turbulent flow through the stent and decrease the risk of stent thrombosis.[0039]
• Important physical properties of the implant to consider include, but are not limited to: length, (stent) diameter in the expanded state, degree of flexibility and lateral stiffness, and the like. These physical properties will be modified to account for such factors as lumen diameter, length of any stenosis, type of luminal structure, or solid organ or tissue involved.[0040]
• Metals such as stainless steel and tantalum, or metal alloys such as alloys of nickel and titanium, specifically including superelastic alloys such as NITINOL or Elgiloy which are commonly used by those of skill in the art, may be used to form the implants. However, the implants may also be made from biodegradable polymers, e.g., copolymers of lactic and glycolic acid, or nonbiodegradable polymers, e.g., copolymers of ethylene and vinyl acetate.[0041]
• The implants may also include a therapeutic agent. Examples of therapeutic agents that may be used in the implants include, but are not limited to, antibiotics, anticoagulants, antifungal agents, anti-inflammatory agents, antineoplastic agents, antithrombotic agents, endothelialization promoting agents, free radical scavengers, immunosuppressive agents, thrombolytic agents, and any combination thereof. If the implant is a stent, an antithrombotic agent is preferably included.[0042]
• Examples of selective antithrombotic agents include acetylsalicylic acid, argatroban, cilostazol, copidogrel, cloricromen, dalteparin, daltroban, defibrotide, dipyridamole, enoxaparin, epoprostenol, indobufen, iloprost, integrelin, isbogrel, lamifiban, lamoparan, nadroparin, ozagrel, picotamide, plafibride, reviparin sodium, ridogrel, sulfinpyrazone, taprostene, ticlopidine, tinzaparin, tirofiban, triflusal, and any of their derivatives.[0043]
• The therapeutic agent may be coated onto the implant, mixed with a biodegradable polymer or other suitable temporary carrier and then coated onto the implant, or, when the implant is made from a polymeric material, dispersed throughout the polymer.[0044]
• The implant may include a radioactive material. The radioactive material may be selected on the basis of its use. For instance, the material may be included in an implant where the implant is in the form of a stent that is to be situated over a vascular stenosis. The radioactivity lowers the incidence of re-stenosis. Additionally, the radioactivity may serve the function of a tracer, to allow detection of the location of the implant during the procedure or anytime thereafter. Suitable radioactive tracers include isotopes of gallium, iodine, technetium, and thallium.[0045]
Release Mechanism
• In one variation of the generic implant delivery system, as shown in FIG. 1A, the implant delivery system includes a[0046]delivery guide100.Delivery guide100 has aproximal section102 and adistal section104. An implant, in this case depicted as astent106, surrounds a portion of thedistal section104 of the delivery guide, and is releasably attached to thedistal section104 of the delivery guide. Theimplant106, as shown in FIG. 11B, is concentrically adjacent to thedelivery guide100. Although I show the stent in FIGS. 1A and 1B as the implant (106), I depict it in this fashion solely for the illustrative purpose of indicating the siting of theimplant106 on thedelivery guide100 with the distal and proximal implant release mechanism (109,111). Various implant release mechanisms or structures are discussed in greater detail below.
• [0047]Implant106 is shown to be directly attached to, is contiguous to, thedelivery guide100 at theproximal end108 of the implant and distal end110 of the implant. In the system shown in FIG. 1A,implant106 may be secured to thedelivery guide100 by such generic controllably releasable mechanisms as mechanical, thermal, hydraulic, and electrolytic mechanisms, or a combination thereof. Examples of these release mechanisms will be discussed below.
• Consequently, release of the[0048]implant106 from thedelivery guide100 may be achieved through a mechanical detachment process involving, e.g., twisting of the delivery guide, such as described by Amplatz in U.S. Pat. No. 6,468,301, or translational movement of the delivery guide in relation to the implant. Implant release may also be achieved using a thermally detachable joint, such as described in U.S. Pat. No. 5,108,407 to Geremia et al., an electrolytic detachable joint, such as described in U.S. Pat. Nos. 5,122,136 and 5,354,295, both to Gulglielmi et al., or a combination thereof.
• In another variation, and as shown in FIG. 2, the system includes a[0049]tubular member200 co-axially mounted on adelivery guide202.Tubular member200 may form a component of thedelivery guide202 that cooperates with one or more of the releasable mentioned joints on the implant (209,211) to release those joints (and therefore, release the implant204) upon application of a releasing movement, axial or twisting. An implant, e.g., astent204, is mounted on adistal section206 of the delivery guide and thedistal end208 of the tubular member is attached to theproximal end210 of the stent. The distal end212 of the stent is attached using a releasable joint211 to thedistal section206 of thedelivery guide202.
• As mentioned above, I may use a tubular member mounted coaxially about the delivery guide, that slides axially about that delivery guide, as a actuator to release the implant. The outer tubular member may also be used to pre-position the implant. For instance, prior to release, the outer tubular member may be used to expand the implant to therefore obscure its placement, and so to permit adjustment of the placement. FIG. 3A shows a[0050]stent300 expanding astubular member302 is moved distally on thedelivery guide304, in the direction of the arrow. The stent is then released from the delivery guide. Specifically, thedistal end306 of the stent is released from adistal section308 of the delivery guide, followed by release of theproximal end310 of the stent from thedistal end312 of the tubular member. As mentioned above, thestent300 may be secured to adistal section308 of the delivery guide by such mechanisms as lock and key arrangements, biocompatible adhesives, soldering, or a combination thereof. Consequently, stent release may be achieved through a mechanical detachment process, a thermal detachment process (e.g., by heat produced from an exothermic reaction), an electrolytic detachment process, or a combination thereof.
• FIGS. 3B and 3C show yet another variation of a stent release mechanism. In FIG. 3B,[0051]brackets314 may be used to couple thestent300 to thedistal section308 of the delivery guide. Separation of thestent306 from thebrackets314, e.g., by one of the detachment processes mentioned above, releases thedistal end306 of the stent from adistal section308 of the delivery guide, allowing the stentdistal end306 to expand in the tubular organ.
• Controllable release of an end of an implant from the delivery guide may be accomplished using the structure of FIG. 3C[0052]₁.Brackets314 couple the stentproximal end310 to thedistal region312 of thetubular member313 that forms a portion of the delivery guide. Thebrackets314 have a rampedregion316 which are proximally adjacent to an enlarged (and perhaps ball- or barrel-shaped)portion318 of the delivery guide andbracket arms320. The delivery guide and stent each have a delivery diameter, and these delivery diameters may be substantially equal prior to release of the stent. When theactuator305 is moved proximally, as shown by the direction of the arrow, the ball-shapedportion318 forces the rampedregions316 of the brackets outward from the delivery guide axis, in a radial fashion, causing thebracket arms320 to be displaced radially outwardly from theproximal end310 of the stent, thereby releasing the stentproximal end310.
• FIG. 3C[0053]₂shows the results of moving theactuator305 proximally. The clips (316) have rotated as shown due to the force exerted upon the ramps (317) by the ball (318). The implant (320) has expanded in diameter from that found in its undelivered form.
• The actuator may be attached, perhaps with a distal radioopaque coil or directly, to a distal section (not shown) of the guide member.[0054]
• FIG. 3D[0055]₁, shows adelivery system319 in which the two ends of theimplant321 may be independently deployed by using anactuator304 having a proximal releasingball322 and a distal releasingball327. Theimplant321 is located in a gap between sections of the delivery guide and are releasably attached to the delivery guide by brackets or clips. The two balls are spaced in such a way that, in the variation shown in FIG. 3D₁, thedistal ball327 releases thedistal end331 ofimplant321 and theproximal ball322 then releases theproximal end329 ofimplant321 upon additional proximal movement ofactuator304. This sequence of events is shown in FIGS. 3D₁,3D₂, and3D₃. Theimplant321, is shown to be completely released in FIG. 3D₃. In this variation, theimplant321 may be self-expanding, e.g., constructed of a superelastic alloy such as nitinol or another alloy having high elasticity, e.g., an appropriate stainless steel.
• A structure similar to that shown in FIGS. 3D[0056]₁,3D₂, and3D₃may also be used to deploy an implant using fluid pressure as the releasing impetus.
• FIGS. 3E[0057]₁,3E₂,3E₃and3E₄show a hydraulic variation. Shown are thedelivery guide350, having ahollow lumen352, a self-expanding implant354 (shown variously as non-expanded (e.g., in a “first form”) in FIG. 3E₁, partially expanded in FIG. 3E₂, and fully expanded in FIGS. 3E₃and3E₄(e.g., in a “second form”)), and anactuator356 with a sealingmember358 and a radio-opaque member360.
• The implant[0058]354 (here shown to be a stent or the like) is held to thedelivery guide350 during delivery to the selected treatment site usingdistal brackets364 andproximal brackets362 or clips or the like. The proximal and distal brackets (364,362) either include regions that cooperate with the fluid inlumen352 to move upon application of increased pressure in thatlumen352 and release theimplant350 or move in concert with a separate pressure sensitive motion component.
• FIG. 3E[0059]₁shows theactuator356 as the sealingmember358 approaches the various orifices or openings (proximal orifices366 and distal orifices368) communicating from thelumen356 to the hydraulically or fluidly actuatable clips or retaining brackets (proximal brackets362 and distal brackets364).
• Included in the description of this variation is a radio-[0060]opaque marker360 on theactuator shaft356 that allows the user to simply line up thatactuator marker360 with a corresponding radio-opaque marker370 or thedelivery guide350, increase the pressure in lumen352 (via syringe, pump, etc.) and deploy theproximal end371 ofimplant354. The interior pressure raises or rotates the proximal clips orbrackets362 and moves them out of contact with theimplant354. FIG. 3E₂shows the movement of the proximal end ofimplant354 away from thedelivery guide350.
• FIG. 3E[0061]₃shows the axial movement ofactuator356 distally to a position where the sealingmember358 is positioned to actuate distal clips orbrackets364 and release the distal end of implant. Again, a radio-opaque marker374 (perhaps with an additional identification band376) has been depicted to show alignment of the radio-opaque marker orband360 on theactuator shaft356 prior to the increase in pressure for deployment.
• FIG. 3E[0062]₄shows final deployment at theimplant354 and proximal movement at theactuator356, just prior to withdrawal of thedelivery guide350. The distal and proximal clips or brackets (362,364) have relaxed to the surface of thedelivery guide350.
• Alternatives to certain of the elements shown in the variation found in FIGS. 3E[0063]₁to3E₄is seen in FIGS. 3F₁and3F₂and includes, e.g., acover element380 to block or coverproximal orifices366 during the pressurization of thedistal orifices368. Thecover element380 includesholes382 to allow fluid flow past thecover element380.
• FIG. 3G, shows a variation of the described system in which an implant or[0064]stent371 is maintained in position on ahollow delivery guide373 usingspring clips375 proximally and377 distally. The spring clips hold theimplant371 in place during delivery and againstguide member373. Anactuator379 is used to remove theclips375,377 sequentially and to release each end ofimplant371 in an independent fashion.Clips375 and377, after actuation or release, remain interior to theguide member373 for later removal with that guide member. The system shown in FIGS. 3G₁,3G₂and3G₃may be used to deliver a number of implants in a sequential fashion. Since the retainer clips375,377 remain within theguide member373 after delivery, theactuator379 is able to slide past the site onguide member373 where theclips375,377 resided prior toimplant371 deployment, down to and distally to a site on the guide member having another implant for subsequent delivery. Consequently, an arrangement such as this may be used to deploy, in a sequential fashion, a number of stents or the like without withdrawal of the guide member.
• In the variation shown in FIGS. 3G[0065]₁,3G₂and3G₃, theclips375 and377 are spring-biased to collapse within thelumen381 of theguide member373 once they are pushed into therespective slots383 provided for such retraction. Such spring loaded clips retain the self expanding stent orimplant371 onto the face ofguide member373. Each ofclips375,377 are shown in this variation to havehook members387,389 that engage theimplant371, often axially stretching theimplant371 and maintaining the delivery radius of theimplant371 as shown.
• As shown in FIG. 3G[0066]₁,actuator379 is pushed distally along the outer surface ofguide member373 until it contacts the proximal end ofclip375. Further distal movement ofactuator379 urges clip375 intolumen381 thereby rotatinghorn387 out of cooperating receptacle area inimplant371.
• FIG. 3G[0067]₂shows the results of such movement afterclip375 has completed its springed closure withinlumen381. As shown in that Figure, the proximal end ofimplant371 has expanded and yet the distal end ofimplant371 remains closed and hooked todistal clip377. This semi-open condition allows for some adjustment of the implant if needed. FIG. 3G₃shows the results of additional distal movement ofactuator379 until it contacts distal clip377 (shown in FIG. 3G₃in its collapsed form ) and thereby allowing the distal end ofimplant371 to self-expand into the chosen treatment site.
• FIG. 3G[0068]₃shows thatguide member379 is free.Implant371 is shown in its self expanded form no longer adjacent thecentral guide member379.Actuator379 is situated withinimplant371 and is no longer in contact withproximal clip375 nordistal clip377.Actuator379 is thus able to continue distally to another implant containing site positioned in a more distal site on theguide member373.
• The mechanical variation shown in FIGS. 3G[0069]₁,3G₂,3G₃may be modified in such a way that the actuator is interior to the lumen of the guide member and deploys the implant upon distal movement of the actuator by providing an actuator with a slot or other “room-making” provisions in the actuator. The actuator and any retained clips would then be used to actuate the clips in the next more distal implant if so desired.
• In yet a further variation, the system releases an implant (shown as a stent[0070]404 in FIG. 4) attached to adelivery guide400 by one ormore attachment arms402 positioned, e.g., at the implant proximal and distal ends, by sliding atubular member406, mounted co-axially on thedelivery guide400, distally over thedelivery guide400. The stent404 is secured to thedelivery guide400 when theattachment arms402 are in a radially expanded configuration (as illustrated in FIG. 4). Thetubular member406 urges theattachment arms402 into a compressed configuration as it slides distally over thedelivery guide400, in the direction of the arrow. When theattachment arms402 are compressed by thetubular member406, they are moved inward from the stent404, toward the central axis of thedelivery guide400, thereby releasing the stent404 from thedelivery guide400. Stent detachment occurs in a serial fashion as thetubular member406 is moved distally, with detachment of the stent proximal end408 occurring before detachment at the stent distal end410. Consequently, if the stent position requires readjustment after detachment of the stent proximal end, the stent may be repositioned prior to detaching the stent distal end. In one variation, the tubular member is a balloon catheter.
• The[0071]attachment arms402 are generally made from the same materials as thedelivery guide400, e.g., stainless steel or nickel-titanium alloy, and will typically have a length, thickness, shape, and flexibility appropriate for its intended mechanism of release. The distal ends412 of the attachment arms may be of any design, so long as one or more of them, when in a radially expanded configuration, secures a portion of a stent to a delivery guide, and when in a compressed configuration, releases that same stent portion from the delivery guide.
• The tubular member may be a thin-walled tube (e.g., approximately 0.005 cm (0.002 inches) in thickness) with an outside diameter ranging from about 0.025 cm to about 0.139 cm (0.010 inches to about 0.055 inches), more usually from about 0.025 cm to about 0.05 cm (0.010 inches to about 0.020 inches), and more usually still from about 0.025 cm to about 0.035 cm (0.010 inches to about 0.014 inches). Depending on such factors as degree of flexibility or durometer required, they may be made from various metals or metal alloys, including, but not limited to, stainless steel and nickel-titanium alloy, or from various polymers, such as polyvinyl chloride, polyethylene, polyethylene terephthalate, and polyurethane.[0072]
• FIGS. 5A, 5B, and[0073]5C show a variation of the describeddelivery system500 in which a member of electrolytic delivery joints are used to deploy animplant502, such as a stent.
• The electrolytic delivery joints shown here (e.g.,[0074]504 in FIG. 5C) are well known as controllable delivery joints for placement of vaso-occlusive coils. One such commercially available device using an electrolytically detachable joint is sold by Target Therapeutics, a subsidiary of Boston Scientific Corp., as the Guglielmi Detachable Coil (or “GDC”). Numerous patents to Dr. Guglielmi describe the theory of its use.
• In essence, the electrolytically erodible joint is a section of an electrical circuit that is not insulated and is of a metallic material that does not form insulating oxides when exposed to an aqueous environment (e.g., aluminum and tantalum) and is sufficiently “non-noble” that is will either electrolytically erode by ionic dissolution into an anatomical fluid or, perhaps, electrochemically erode by forming readily soluble oxides or salts.[0075]
• The erodible joint[0076]504 shown in FIG. 5C is a bare metal of a size, diameter, etc. that erodes away when a current is applied to insulatedwire506. The current flow is from a power supply through insulatedwire506, bare joint504, into the ionic anatomical fluid surrounding the site to be treated, and back to a return electrode situated perhaps on the patient's skin and then back to the power supply. The current flows through the circuit so long as the joint504 exists.
• With that background, FIG. 5A shows a device having several joints ([0077]504,508,510,512) that each may be independently severed to controllably deploy theimplant502.Implant502 is shown having coils (514,516) that are terminated at each end by an erodible joint and that, prior to the severing of a joint, hold thisimplant502 to the surface of thedelivery member520. Theimplant500 is self-expanding, once released. The wires forming the two coils in this variation slide within the implant or “uncoil” and thereby allow the implant body itself to expand. The coils may comprise (if electrically connected to the erodible joint) a metal that is higher in the Mendelev Electromotive Series than is the composition at the electrolytic joint or the coils may comprise a polymer that may be bio-erodible or not.
• In any case, a suitable way to assure that the coils ([0078]514,516) maintain the low profile of theimplant502 during delivery is via the placement of the various conductive wires (506,516,518,520) through the adjacent holes (524,526,528) and fill the holes with e.g., an epoxy to hold all in place. Independently causing current to flow through each of the joints will release the implant in the region of the released joint Once all joints are eroded, the implant is released.
• Although release from proximal and distal ends of the tubular form of the implants has been described, detachment from a delivery guide is not so limited. In another variation, the stent is attached to the delivery guide at one or more positions along the length of the stent, in addition to attachment at the proximal and distal implant ends. Once the distal stent end is released, the additional attachments may be independently released until detachment at the proximal implant end releases the implant entirely from the delivery guide. Serial release may provide better control of positioning in tubular organs.[0079]
• FIGS. 5D and 5E show in more detail, the components of an electrolytic joint (as may be found in FIGS. 5A, 5B and[0080]5C) and another electrically actuated joint using a meltable or softenable or polymerically sizable joint
• FIG. 5D shows the[0081]insulated wire524 with insulation523 andconductor525. The electrolytic joint504 is also shown. In this variation, thewire524 is shown to be secured into thedelivery guide wall520 by, e.g., an epoxy527, an alternative or cooperative band orcomponent529 holding thewire524 to the surface ofguide member520 is also shown. After erodable joint504 is eroded, the implant of502 expands and leaves thesecurement band529 on thedelivery guide520.
• FIG. 5E shows a similar variation but the joint comprises a thermoplastic adhesive or[0082]shape changing polymer531 situated on the end ofwire525 and within a cup orother receptacle533. The adhesive is of the type that changes form or viscosity upon application of current to the joint. In this variation, the thermoplastic is rendered conductive, but resistive, by introduction of material such as carbon black into the polymeric adhesive. As soon as the polymer changes its shape, form, or phase, the implant expands to the desired form about thecentral guide member520 again, the wire may be held in place with an adhesive527 if so desired.
• Although the figures show wires and other remnants of the joints remaining exterior to the[0083]central guide member520 and the others shown and described here, it is desirable that these not be situated in such a way that they will harm the tissues into which they are placed.
Delivery Method
• The implant delivery devices described herewith may include multiple implants on a single delivery guide or may be used in conjunction with other instruments, as seen appropriate, to treat the target site. In general, the tubular organ of interest is percutaneously accessed, but the method of accessing will usually be dependent on the anatomy of the organ, medical condition being treated, health status of the subject, and the like. Consequently, access by a laparoscopic or open procedure may also be obtained.[0084]
• FIGS. 6A-6D show the general method of deploying a stent using my described system. After obtaining access to the tubular organ of interest[0085]600 (blood vessel in FIG. 6A), adelivery guide602 is placed through the selected area ofstenosis604 at the target site. Aballoon catheter606 is then advanced over thedelivery guide602, and balloon angioplasty performed to dilate the area of stenosis604 (FIG. 6B). Theballoon catheter606 is then retracted proximally and thedelivery guide602 exchanged for a stent delivery device608 (FIG. 6C). Appropriate placement of the stent is guided byradioopaque markers616 on thedelivery guide612. Thedistal end610 of the stent is then released from thedelivery guide612. At this point, stent position may again be checked by verifying the location of the radioopaque markers. Theproximal stent end614 is then released from thedelivery guide612.
• If desired, an embolic filter may be used during stent deployment to filter any debris generated during the procedure. The filter will usually be attached to the delivery guide such that it filters debris distal to the stent, but may also be attached to the delivery guide proximal to the stent, or both distal and proximal to the stent. The filter may be of any design, as long as it does not affect the substantially atraumatic, low profile, and controlled release characteristics of the stent delivery device. Typically, the filter is basket-shaped, and made from a shape-memory material, e.g., an alloy of titanium and nickel. The filter will usually be contained within the balloon catheter lumen, and deployed to its pre-designed shape once the balloon catheter is removed. Following placement of the stent, the balloon catheter may be advanced over the delivery guide to enclose the filter with any accumulated debris. The balloon catheter, filter, and delivery guide may then be removed from the body.[0086]
Applications
• The implant delivery system may be used in mammalian subjects, preferably humans. Mammals include, but are not limited to, primates, farm animals, sport animals, cats, dogs, rabbits, mice, and rats.[0087]
• The system may be employed for implant delivery into lumens of tubular organs including, but not limited to, blood vessels (including intracranial vessels, large vessels, peripheral vessels, aneurysms, arteriovenous malformations, arteriovenous fistulas), ureters, bile ducts, fallopian tubes, cardiac chambers, ducts such as bile ducts and mammary ducts, large and small airways, and hollow organs, e.g., stomach, intestines, and bladder. The system may also be employed for implant delivery into solid organs or tissues including, but not limited to, skin, muscle, fat, brain, liver, kidneys, spleen, and benign and malignant tumors. Preferably, the implant is delivered to a target site in a blood vessel lumen.[0088]
• Clinically, the system may generally be used to treat stenosis of various tubular organs, arising from such etiologies as atherosclerosis, autoimmune conditions, scarring, or exterior compression, e.g., as may be seen with a neoplastic process. The system may also be used to treat medical conditions in which luminal occlusion is desired, e.g., to treat aneurysms, arteriovenous fistulas, and arteriovenous malformations. Furthermore, the system may be employed to deliver implants into such areas as joint spaces, spinal discs, and the intraperitoneal or extraperitoneal spaces.[0089]
• All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes to the same extent as if each individual publication, patent, or patent application were specifically and individually indicated to be so incorporated by reference. Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to those of ordinary skill in the art in light of the teachings of this invention that certain changes and modifications may be made thereto without departing from the spirit and scope of the appended claims.[0090]

Claims (55)

1.-21. (Cancelled, without prejudice)

22. The system ofclaim 24 wherein the implant exterior surface is smooth after deployment.

23. The system ofclaim 24 wherein the implant interior surface is smooth after deployment.

24. A implant delivery system comprising:

an elongate delivery guide member having a proximal end and a distal end, the delivery guide member configured to direct at least one implant having an exterior and interior surface to an anatomical treatment site by manipulation by a user,

the at least one implant having a delivery diameter prior to release of the at least one implant and located proximally of the distal end of the delivery guide member prior to release, and

a plurality of releasable joints, each joint configured to maintain a section of the at least one implant at the delivery diameter until release of the releasable joints, wherein the system is adapted for sequential release of the releasable joints.

25. The system ofclaim 24 wherein the delivery guide member is closed at its distal end.

26. The system ofclaim 24 wherein the delivery guide member has a diameter distally and proximally of the at least one implant that is substantially equal to the at least one implant delivery diameter, whereby a substantially atraumatic implant delivery system is provided.

27. The system ofclaim 24 wherein the delivery guide member has no passageway from its proximal to its distal end.

28. The system ofclaim 24 further comprising an actuator for releasing the releasable joints, and wherein the delivery guide member has only a single passageway from its proximal to its distal end, that passageway contains the actuator, and that actuator does not extend beyond the distal end of the delivery guide member.

29. The system ofclaim 28 wherein the actuator for releasing the releasable joints is affixed to the distal end of the delivery guide member.

30. The system ofclaim 24 wherein the at least one implant comprises exactly one implant.

31. The system ofclaim 24 wherein the at least one implant comprises more than one implant.

32. The system ofclaim 24 wherein the delivery guide member comprises a distal guide section and a proximal guide section and a gap between the distal guide section and the proximal guide section and the at least one implant is located between the distal guide section and the proximal guide section.

33. (Cancelled, without prejudice)

34. The system ofclaim 24 wherein the delivery guide member is tubular in form, having a lumen therein.

35. The system ofclaim 34 further comprising an actuator slidably located at least partially within the delivery guide member lumen and configured to release at least one releasable joint upon axial movement within the delivery guide member.

36,37. (Cancelled, without prejudice).

38. The system ofclaim 34 further comprising an actuator slidably located at least partially within the delivery guide member lumen and configured to release at least one releasable joint upon rotational movement within the delivery guide member.

39. The system ofclaim 34 wherein at least one releasable joint is configured to release upon application of fluid pressure in the delivery guide member lumen and further comprising a fluid director slidably located at least partially within the delivery guide member lumen and configured to direct fluid to and to release that selected at least one releasable joint.

40. The system ofclaim 39 wherein the fluid director is configured to sequentially release the plurality of releasable joints upon application of fluid pressure in the delivery guide member lumen.

41. The system ofclaim 34 wherein the releasable joints are configured to release upon application of a suitable DC current to the releasable joints, the system further comprising an electrical conductor located at least partially within the delivery guide member lumen to supply the suitable DC current to and to thereby release at the releasable joints.

42,43. (Cancelled, without prejudice)

44. The system ofclaim 24 wherein the implant is a stent.

45. The system ofclaim 44 wherein the stent is unsheathed.

46. The system ofclaim 24 wherein the implant is an occlusive coil.

47. The system ofclaim 24 wherein the implant further comprises a therapeutic agent.

48. The system ofclaim 47 wherein the therapeutic agent is selected from the group consisting of antibiotics, anticoagulants, antifungal agents, anti-inflammatory agents, antineoplastic agents, antithrombotic agents, endothelialization promoting agents, free radical scavengers, immunosuppressive agents, thrombolytic agents, and combinations thereof.

49. The system ofclaim 24 wherein the delivery guide member further comprises a radioopaque marker.

50. The system ofclaim 24 having flexibility and remote directability, wherein the remote directability is such that a user may direct the distal end of the delivery guide member into and introduce the at least one implant into a coronary artery solely by manipulation of the delivery guide member from its proximal end.

51.-75. (Cancelled, without prejudice)

76. A system for treating a target site in a tubular organ comprising:

the implant delivery system of any one of claims22-32,34,35,38-41 or44-50; and

a balloon catheter.

77. The system ofclaim 76 further comprising an embolic filter.

78. The system ofclaim 77 wherein the embolic filter is attached to the proximal end of the delivery guide member.

79. The system ofclaim 76 wherein the implant is a stent.

80. The system ofclaim 76 wherein the implant is an occlusive coil.

81. A method for delivering an implant in a subject comprising:

accessing a body region;

advancing an implant delivery guide to a target site in the body region; and

releasing the implant at the target site by releasing one portion of the implant after another in a sequential fashion.

82. The method ofclaim 81 further comprising deploying at least one embolic filter.

83. The method ofclaim 81 wherein the releasing comprises releasing a distal end of the implant from the delivery guide before releasing a proximal end of the implant from the delivery guide.

84. The method ofclaim 81 wherein the releasing comprises a mechanical detachment process.

85. The method ofclaim 81 wherein the releasing comprises a hydraulic detachment process.

86. The method ofclaim 81 wherein the releasing comprises an electrolytic detachment process.

87. The method ofclaim 81 wherein the body region is a tubular or hollow organ.

88. The method ofclaim 87 wherein the tubular or hollow organ is selected from the group consisting of blood vessels, arteriovenous malformations, aneurysms, arteriovenous fistulas, cardiac chambers, bile ducts, mammary ducts, fallopian tubes, ureters, large and small airways, stomach, intestines, and bladder.

89. The method ofclaim 81 wherein the body region is a blood vessel.

90. The method ofclaim 81 wherein the implant is a stent.

91. The method ofclaim 81 wherein the implant is an occlusive coil.

92. The method ofclaim 81 wherein the target site comprises an aneurysm.

93. The method ofclaim 81 wherein the subject is human.

94. The method ofclaim 81 wherein the accessing is performed percutaneously.

95. The method ofclaim 81 wherein the stent implant delivery system is selected from those described in any one of claims22-32,34,35,38-41,44-50 or76-80.

96. The method ofclaim 81 further comprising:

advancing a balloon catheter to the target site;

performing angioplasty with the balloon catheter prior to the releasing of the implant.

97. The system ofclaim 25, wherein an atraumatic tip provides the end closure

98. The system ofclaim 24 wherein the delivery guide member has a distal diameter between about 0.010 and about 0.020 inches, whereby a low-profile delivery system is provided.

99. The system ofclaim 24 wherein the delivery guide member is noninflatable.

100. The system ofclaim 24 wherein the system is guidewireless.

101. The system ofclaim 25, wherein an atraumatic tip provides the end closure

Images