MXPA97007886A - Stenosis implant supply device (stent) with arrollamie membrane - Google Patents

Abstract

A device for deploying radially self-expanding implants and other radially expandable implants includes an internal catheter, an external catheter that surrounds the internal catheter, and a tubular stenosis implant that retains the sheath formed from a winding membrane; bent over itself to provide an internal sheath wrap attached to the internal catheter, and an outer sheath wrap attached to the external catheter, the sheath wraps extend along and enclose a self-expanding stenosis implant radially, to maintain the stenosis implant distally of the internal catheter and in a radially compressed, axially, axially elongated condition distally of the stenosis implant, the inner and outer sheath shells converge and taper distally to define a distal extremity tapered To release the stenosis implant, the external catheter is moved proximally to roll the membrane out of its surrounding relationship with respect to the stenosis implant, while the stenosis implant progressively expands radially, starting at the distal end; when fully retracted upon release of the stenosis implant, the sheath encircles a distal region of the internal catheter, and may provide a protective sheath between the arterial tissue and a dilatation balloon supported along the distal region; A stenosis implant formed from a recovery metal can be plastically deformed to a reduced radius state for delivery, which facilitates the use of a more flexible retention sleeve of the stenosis implant. Another alternative includes securing the sheath proximally to the dilatation balloon, so that retraction of the sheath leaves the dilatation balloon uncovered, instead of covered by the fungus.

Description

STENOSIS IMPLANT SUPPLY DEVICE (STENT) WITH ROLLING MEMBRANE The present invention relates to devices for the deployment of pro-es-splantable in the body thought for its fixation in body lumens, and particularly for the supply and placement of stenosis implants (STENTS) self-expanding radial b other radially expandable stenosis implants. Certain prostheses known as radially self-expanding stenosis implants are useful in a variety of diagnostic and treatment procedures for the patient, for attachment to blood vessels, bile ducts and other lumens to maintain the steps. A highly preferred construction for an au + o-expandable stenosis implant consists of a flexible tubular braided structure formed with helically wound screw-shaped elements, as described in the U.S. Patent nurn. 4,655,771 (Uallsten). The Uallsten document teaches the use of a catheter to supply stenosis implants to the desired treatment site. A pair of claws maintains the stenosis implant at the distal end of the catheter and is controlled by an operative member at the proxirnal end of the catheter to release the stenosis implant after positioning and initial intermediate self-expansion of the stenosis implant. Another proposal to deploy self-expanding stenosis implants is shown in the patent of E.U.fl .. nurn. 4,732,152 (Uallsten et al.) And in the U.S. Patent. N. M. 4.B4Ü.343 (Uallsten et al.). Referring frequently to a "winding membrane" method, this proposal uses a tubular membrane bent over itself to provide a double wall to maintain the self-expanding stenosis implant at the distal end of the catheter. The outer wall of the membrane is movable proximally to reveal the stenosis implant and allow a radial expansion, starting at the distal end of the stenosis implant, in particular, one end of the membrane is attached to a internal catheter or probe, and the other end of the membrane is connected to an external catheter that surrounds the probe. When the external catheter moves proxnnally in relation to the internal catheter, the outer wall of the MEMBRANE is also moved proxirnally, to discover the stenosis implant and allow its radial self-expansion. "Method to deploy an implant stenosis implant in the body". This application describes various stents implant deployment devices that employ indoor and outdoor catheters for deploying prostheses that include radially self-expanding stenotic implants. One of these versions (Figures 9-13) employs a controlled winding membrane by manipulating the catheters to release a stenosis implant for self-expansion.

The nnpLant-es of LS stents constructed with a recoverable metal, for example a nickel titanium alloy such as that sold under the trade name Nitenol, can be used instead of self-expanding stenosis implants for certain applications. . A recovery metaL stenosis implant may be formed with an expanded radius coniguration, then plastically deformed while cooling to a reduced radius configuration for delivery to a treatment site, followed by delivery. it heats the stenosis implant, which causes it to expand radially towards its original radius and to contact the tissue at the treatment site. Devices for supplying retrieval metal stenosis implants and radiating self-expanding stenosis implants may be constructed in accordance with the same general procedures. While they are quite effective in certain applications, these devices generally incorporate interior catheters, probes or other members encircled by the stenosis implant that is deployed, and generally having a relatively rigid outer member, usually an outer catheter, to surround and maintain the stenosis implant under radial compression. Such devices may be too large to deploy the stenosis implants within the narrower blood vessels and other body passages, and may be difficult to maneuver distally from the serpentine passages defined by the lumens of the blood vessels. body. Frequently, during a procedure that includes the deployment of the stenosis implant, it is desirable to force the stenosis iinplant-e against the surrounding tissue after its deployment. This ensures a more secure positioning of the stenosis implant, a more uniform lumen for fluid flow, and also reliably establishes a final axial length (ie, a degree of axial contraction). of the stenosis implant. It is important that during the treatment procedures of the lesion the final length (or degree of axial contraction) of the stenosis implant after self-expansion is determined, to ensure that a given stenosis implant is of sufficient length in relation to the L5 lesion that is being treated. A dilatation balloon, mounted near the far end! of the catheter-, can be used for this purpose. When such a balloon is used, it would be desirable to provide protection against accidental bursting of the balloon either during or after its inflation. Therefore, an object of the present invention is to provide a device for radially deploying self-expanding stenosis implants, with sufficient axial rigidity and with improved flexibility to accommodate its advance through the narrow and non-linear passages of the body. . Another object is to provide a small diameter stenosis implant that retains the limb for a deployment catheter of the stenosis implant. Another object is to provide a stenosis implant delivery apparatus that provides good tracking characteristics and axial stiffness, whether it is directed through body passages or advanced on guide wire. Still another object is to provide a device for supplying a radially self-expanding stenosis implant with an expandable balloon against the stenosis implant supplied to force it against the surrounding tissue, and which also incorporates a fluid-tight membrane surrounding it. to the dilatation balloon to provide additional protection during high pressure dilatation procedures.

BRIEF DESCRIPTION OF THE INVENTION To achieve these and other objects, a device for deploying an expandable stenosis implant at a treatment site inside the body has been provided. The device includes a first (or internal) catheter and a retention member of the stenosis implant. The member is disposed in the distal end region of the primary catheter and includes an internal envelope extending distally up to the first catheter. The member is turned back on itself to form an outer envelope that extends toward the first catheter. The internal envelope has been adapted to retain a stenosis implant in the reduced state along its axial length, with the stenosis implant located distally of the first catheter. A means is operable to move the outer envelope relative to the first catheter after delivery, to separate the member from its retention in relation to the stenosis implant, to release the stenosis implant-to its expansion at the site of treatment. Preferably, the retention member is a sheath or wrapping membrane surrounding the stenosis implant to maintain the stenosis implant in a reduced state. The preferred sheath comprises a tubular winding membrane. Since the stenosis implant is held distally from the catheter rather than surrounding the catheter, it can be provided with a diameter smaller than that of the catheter. The inner envelope preferably has an internal diameter no greater than the external diameter of the first catheter. When the stenosis implant is radially self-expanding, the internal sheath alone (or a combination of the internal and external sheaths) retains the stenosis implant in a state of axially elongated, radially compressed. The compressed stenosis implant and sheath cooperate with one another to provide an improved distal extremity for the catheter. In addition to the reduced diameter, the compressed stenosis implant and the membrane provide a highly favorable combination of axial rigidity and elasticity of the limb during bending to adapt to the tortuous passages of the blood vessels and other lumens of the body. it obtains by forming the sheath so that b forms a tapered distal extremity. This is done by forming the sheath so that the inner and outer sheaths, near the point where the sheath is pulled back on itself, converge in the distal direction. If desired, axial filaments or other reinforcements may be provided throughout.

LO The cover. The release of the stenosis implant includes retracting the sheath, i.e., moving the outer sheath of the proximal sheath to loosen or wrap the membrane of the sheath from the stenosis implant. Preferably, this L5 is performed with a second catheter or external catheter that surrounds the first catheter and that is attached by the distal end to the outer sheath of the sheath. The sheath is rolled by moving the external catheter proximally in relation to the first (internal) catheter. The release is increased by a fluid-tight construction of the membrane that facilitates the introduction of a fluid under pressure between the inner and outer shells. Alternatively, the selection of low friction material for the membrane, or the application of low friction coatings to the membrane between the inner and outer sheath wraps, may allow the winding membrane to be removed without applying pressure between the wraps. In accordance with another aspect of the invention, a dilatation balloon is provided near the distal end of the catheter. The sheath has sufficient length in its combined internal and external sheaths to overcome the axial distance from the distal end of the catheter to a proxirnal end of the dilatation balloon. Accordingly, the sheath after retraction extends proxirnally along the catheter - from the axial end, in surrounding relation to the balloon along the entire length of the balloon. With this arrangement, the sheath provides a protective wrap particularly useful during high pressure angioplasty procedures. In case of bursting of the dilatation balloon, the dilatation fluid will tend to flow proxinally along the sheath and the catheter and remain inside the sheath. In this way, the sheath protects the artery or other tissue against the risk of exposure to the dilation fluid of the balloon that bursts or drips. The sheath also prevents any resulting fragments of the balloon material from escaping into the bloodstream. A highly preferred device employs an outer catheter with a lumen containing an inner catheter, with the opposite ends of the sheath secured to the respective catheters and with the inner and outer sheaths of the sheath extending distally from both catheters. The external catheter provides a reliable means to pull proximally from the outer sheath of the sheath to release the stenosis implant. Fluids may be provided to the area between the sheath wraps of the sheath by means of an external catheter lumen. The sheath alone retains the stenosis implant, for an axially rigid deployment device that is even more maneuverable and smaller in diameter. When the socket is retracted or withdrawn proximally, the distal end of the internal catheter becomes the distal end of the device. The sheath is superimposed and encircles a dilatation balloon to protect the tissue from exposure to the balloon dilation fluid jet in the event of a balloon rupture during the angioplasty process.

BRIEF DESCRIPTION OF THE DRAWINGS For a better appreciation of the foregoing and other advantages, reference is made to the detailed description which follows and to the drawings, in which: Figure 1 is an elevation of a device for supplying and deploying a self-healing stenosis implant - radially expanded in accordance with the present invention, - Figures 2 and 3 are views in greater section of parts of Figure 1; Figure 4 is a sectional view taken along line 4-4 of Figure 1; Figure 5 is another larger view of the 1U end dista i of the device; Figures 6-9 are schematic views illustrating the use of the device for deploying a radially self-expanding stenosis implant; Figure 10 is a sectional elevation of an end zone of a device of an alternative embodiment for radially deploying self-expanding stenosis implants; Figure 11 is an elevation view of a distal area of another deployment device of another alternative embodiment; Figure 12 is a sectional view taken along line 12-12 of Figure 11, and Figures 13 and 14 illustrate the distal end region of an alternative embodiment device.

DETAILED DESCRIPTION OF THE MODALITIES Turning now to the drawings, there is shown in Figure 1 a deployment device (16) for supplying a prosthesis, in particular a radially self-expanding stenosis implant, to a desired treatment site within a lumen. body such as an artery. After providing the stenosis implant, the deployment device (16) is manipulated to controlly release the stenosis implant for its radial self-expansion to a fixation site inside the lumen, following the deployment, a balloon mounted on the The device is expanded to force the balloon radially outwardly against the surrounding tissue, to more reliably establish a final position of the stenosis implant and an axial length. The deployment device (16) includes an elongated and flexible external catheter (18) constructed with a biocornpatible thermoplastic elastomer, for example polyurethane or nylon. The external diameter of the catheter is typically comprised within the range of 2-42 Fr. (0.7-14 nm). The preferred diameter of the catheter depends mainly on the intended use. For example, the preferred range for coronary applications is around 2-7 Fr. (0.7-2.3 rnrn), with peripheral applications pointing to diameters of about 2-12 Fr. (0.7-4 Rn m). For abdominal, esophageal and tracheal aortic aneurysm applications, the most preferred interval is 7-42 Fr. (2.3-14 rnrn). The external catheter (18) has a lumen (20) that runs the length of the cat. A tubular sheath (22) has been mounted on the end (24) distal catheter (18). The sheath (22) extends distally beyond the catheter and is shaped to provide a distally converging end (26). A part of the external catheter is broken to discover an elongated and flexible inner catheter (28) contained within the lumen (20). The inner catheter can be constructed with materials similar to those used to form the external catheter. The internal catheter (28) has a lumen (30) running the length of the catheter, to contain a guide wire (32), shown to extend distally beyond the extremity (26). At its proximal end, the catheter (18) is mounted on a valve (34). The valve includes an access (36) for receiving the fluids supplied by means of an extension tube (38). Such fluids advance through the vaLvula to the lumen (30), then to the surrounding region of the limb (26). A portion of the valve (34) is spaced apart to reveal an internal seal (40) that supports an elongated stainless steel tube (42) to drive the axial movement of the valve. The stainless steel tube extends distally from the valve to the Lumen (20) of the external catheter, and its distal end is attached to the proxirnal region of the internal catheter (28). The stainless steel tube can extend from 10 to 200 mm distally along the lumen (20), advantageously increasing the axial rigidity of the device (16). The steel tube (42) can be punctured or formed in the manner of a coil near the distal end of the catheter to improve its flexural flexibility. The catheters (18) and (28) can be moved axially one with respect to the other, by manual manipulation to move the valve (34) relative to the steel tube (42). A hub (44) has been secured to the proximal end of the stainless steel tube (42). For example, by moving the valve proximally while the steel tube is held fixed, the external catheter is retracted, that is, the catheter (18) is moved proximally axially relative to the internal catheter (28). The sheath (22), often identified as a winding membrane, is foldable and flexible, and is constructed of a suitable thermoplastic elastomer compatible with the body such as polyurethane. It can also be used- polyethylene, nylon and its copolymers. As best seen in Figure 2, the sheath (22) is folded over itself to form an inner sheath wrap (46) and an adjacent outer wrap (48), both being tubular. The sheath (22) is formed so that both shells (46) and (48) converge in an axial distal direction along the extremity (26). A proximal end (50) of the outer sheath is mounted on the distal end (24) of the external catheter (18), in an annular, fluid-tight seal. An opposite extrusion of the sheath, that is, a proximal end (52) of the inner sheath, is similarly clamped to the distal end (54) of the internal catheter (28), over most of its length. length, the sheath (22) extends axially so that its wall, in particular the inner sheath (46), defines an extension or lumen (30) for the guiding thread. At the distal extremity there is an aberration of reduced size, but sufficient to admit the guide wire 32 and provide a transition zone from the guide wire to the shrunk stenosis implant. A stenosis implant (56) that radially self-expands is contained by the sheath (22), completely distally of the internal catheter (28). The stenosis implant (55) has a woven or mesh construction, consisting of helically wound twisted and stranded filaments or perforated tubing of an elastic material, for example, a metal compatible with the body such as stainless steel or an alloy of nickel-titanium. The stenosis implant can also be formed with an elastic polymer such as polypropylene or polyethylene. As shown in Figure 2, the stenosis indicator (56) elastically forms a supply configuration that reduces its radius and increases its axial length compared to its normal shape when it is not subjected to external stress. The inner and outer envelopes (46) and (48) encircle the stenosis implant and cooperate to maintain it in the delivery configuration. When the stenosis implant (56) is compressed radially as shown, its elastic recovery force is applied radially against the sheaths (46) and (48) of the sheath. These casings of the sheath expand in response to the force of the stenosis implant (56), until a recovery force of the casings contours the recovery force of the stenosis implant. The expansion of the sheath is preferably virtually negligible. Alternatively, the stenosis implant may be formed with a recovery metal, such as the nickel-t-tam alloy sold under the trade name Nitenol. Such a stenosis implant is plastically deformable, as long as it remains sufficiently cold, to a reduced radius supply configuration. While it is cold, (for example, at or below ambient temperature), the stenosis implant tends to remain in a reduced radius state. Accordingly, the surrounding sheath may have greater elasticity if desired, since the sheath need not counteract the resilient force of recovery of the stenosis implant. When the implant of recovery metal stenosis is provided and positioned in the treatment site, it is heated, which causes the stenosis implant to expand radially towards its original state of greater radius, and toward an intimate contact with the implant. tissue at the treatment site once the surrounding sheath has been retracted. The sheath (22) is retractable by moving the outer sheath (48) proximally relative to the inner sheath (46). A hydrophilic material, for example polyvinyl prioladone, is applied to the sheath (22) along the outer surface of the inner sheath (46) and the inner surface of the outer sheath (48). You can also use sil cona or other lubricants. A liquid lubricant and priming fluid can be provided between the sheath wraps, through the Lumen (20). The coating and the lubricant facilitate the sliding of the inner and outer wraps one with respect to the other, during the retraction. As can be seen better in Figure 5, the sheath (22) is especially shaped in the region of the distal extremity. More particularly, a region (66) d stal of the outer sheath and a distal region (68) of the inner sheath are tapering to converge distally. In this way, not only the profile of the extremity converges; its thickness, likewise, decreases in the distant direction]. The regions (66) and (68) further provide a transition region on which the sheath (22) is treated to substantially alter its hardness. More particularly, the sheath (22) and the stenosis implant (56) contracted over most of its length are relatively rigid. In the transition region, the hardness decreases uniformly and considerably to a soft distal end of the limb. More particularly, the distal end hardness tester (Shore Hardness Test) is within the range of 20D-55D, and preferably is around 90A. In addition, an annular projection (70) has been formed in the sheath along the inner sheath (46) to provide a better transition from the shrinkage region of the relatively rigid stenosis implant to the soft distal end.

A micropore (60) has been formed through the outer shell (48) to allow the exit of liquids from the space between the shells (46) and (48) of the sheath. If desired, the diameter of the micropore can be selected to hold liquids between sheaths of the sheath at a predetermined pressure. A typical diameter for the micropore (69) is around 0.001 inches (0.0254 nm). Depending on the application, the diameter of the micropore may be in the range of about 0.0005 to 0, L2 inches (0.0127-J rnm). With the sheath (22) in the state of retention of the stenosis implant as shown in Figure 2, the distal region along the stenosis implant can conform the serpentine arterial passages as the device (16) is advanced over the guide wire (32) to the intended treatment site. The regions (66) and (68) of soft limb and of transitions r-educate the risk of damaging the arterial walls or other tissues as the device is advanced. Proximally to the distal end (54) (Figure 3), a balloon (58) is attached to the internal catheter in a fluid-tight manner in a proximal neck (60) and in a distal neck (b2). A lumen (64) for inflation of the balloon has been formed in the internal catheter, and is open towards the interior of the balloon (58), whereby a pressurized fluid can be provided for inflation of the balloon to radially expand the balloon (58). 58). You can use markers (65) and (67) L8 radiopaque to fluorescently indicate the location of the bal n. Using the device (16) to position and fix the stenosis implant (56), the initial step consists of positioning the guide wire (32) inside the patient's body using a guide cannula (not shown) . This leaves the guide wire (32) in its position along an artery or other lumen, with a proxirnal portion of the guide wire outside the patient. The deployment device (16) is advanced over the guide wire starting at the proximal portion L, the guide wire being received in the lumen (30) of the guide wire. The physician or other continues to advance the device (16) until the distal end region, which includes the stenosis implant (56), is positioned at the treatment site, eg, a lesion (72) along the an artery (74) (Figure 6). Preferably, the distal extremity (26) is beyond the Injury (72). The stenosis implant (56), still maintained inside the sheath, is aligned axially with the lesion. The sheath (22) remains in the state of retention of the stenosis implant. With the device (16) positioned in this way, the doctor maintains the tube (42) of stainless steel substantially fixed while moving the valve (34) in the proximal direction. This moves the external catheter (18) proxirnally in relation to the internal catheter, also pulling proxirnally the outer sheath (48) of the sheath.

Lotus also moves proxirnally the limb (26), that is, the position in which the sheath (22) turns back on itself. Meanwhile, the internal catheter (28) supports against the stenosis implant (56) to avoid any substantial migration proximally of the stenosis implant. Accordingly, the membrane is rolled or detached from its surrounding relationship with respect to the stenosis implant, allowing the stenosis implant to progressively self-expand radially, beginning at its distal end (Figure 7). The continued retraction of the sheath (22) results in the complete release of the stenosis implant (Figure 8). The stenosis implant (56) has self-expanded to a diameter of up to 30 times the diameter of the external catheter (18). When the sheath (22) is completely retracted, the distal end of the internal catheter becomes the distal end of the device, then, the device (16) is advanced distally to align axially between the balloon (58) inside the stenosis implant (56). Following this alignment, pressurized fluid is supplied to the balloon (58) through the inflation lumen (64) of the balloon, to expand the balloon against the stenosis implant (56). The dilating pressure of the balloon (58) achieves several beneficial results. First, the stenosis implant (56) is pressed radially towards a firm engagement with the surrounding tissue of the arterial wall, to reduce the risk of migration of the stenosis implant and to facilitate more laminar blood flow. Secondly, the additional radial expansion is accompanied by an axial reduction of the stenosis implant, so as to approach it nearer! to a final axial dimension of stenosis implant that might otherwise occur over a longer period of time (approximately 1 hour to 1 day). This allows a more reliable determination on whether the stenosis implant (56) is long enough to cover the lesion. With the stenosis implant (56) placed in its Place- and pressed against the artery (74), the balloon (58) is emptied and the device (16) withdraws proxirnally. The guide wire (32) can also be removed or left in place to allow advancement to any device contemplated in a subsequent procedure. As best seen in Figures 8 and 9, when the external catheter (18) is retracted (ie, when it moves roximally in relation to the internal catheter (28)), it draws the sheath (22) also proximally, from When the winding membrane eventually overlaps and circumvents the expansion balloon (58). The axial length of the sheath is sufficient to provide the extension of the sheath proximal to the dilatation balloon, so that the balloon is completely enclosed and covered. For example, the axial length of the sheath is sufficient if, with the sheath in the state of retention of the stenosis implant, the combined axial length of the inner and outer sheaths (46) and (48) of the sheath exceeds the distance axial from the extreme end (54) to the proximal neck (60). The main advantage of this configuration is that the winding membrane, in addition to retaining the stenosis implant before retraction, provides a protective wrapping between the tissue and the dilatation balloon after retraction. If the dilatation balloon bursts during high-pressure angioplasty, or in the event of a tear or other failure in the dilatation fluid allowed when the balloon is removed, the sheath (22) would cause the dilatation fluid to flow proximally into the lumen ( 20) of the external catheter, thus protecting the surrounding arterial tissue from exposure to the dilation fluid that bursts or drips. Also, as the balloon (58) is inflated (Figure 9), the sheath (22) provides a wrap between the dilatation balloon and the stenosis implant (56) avoiding any damage to the balloon that could result from direct contact with the balloon. the implant of stenosis. The structure and material of the sheath (22) will generally be chosen to provide sufficient strength to counteract the resilience of the stenosis implant (56) elastically compressed during delivery while providing sufficient elasticity so that the sheath is not interfering unduly with balloon dilation (58). In certain applications, a 2 'implant is advantageous) recovery metal stenosis. The sheath, when it is not required to contract an implant (self-expanding stenosis during delivery), may be substantially new.The expanded balloon acts through the sheath (22) to press the stenosis implant (56) - Adjacent to the outside and against the surrounding arterial tissue Momentarily, this radially expands and shortens axially the stenosis invader (56) beyond a state of equilibrium in which the respective forces of recovery In the interior of the stenosis implant and in the surrounding tissue they counteract each other.When the balloon is emptied and removed (58), the stenosis implant (56) contracts slightly radially and lengthens axially to re-establish The balance causes the stenosis implant (56) to over-expand and then contract to equilibrium.As a result, the passage for fluid flow in the artery is smooth and the flow is laminar. The turbulence of the reduced flow, the potential for thrombus formation in the area of the stenosis implant is likewise reduced. The balloon expansion of the stenosis implant also makes it easier for the physician to confirm more reliably that the implanted implanted stenosis has sufficient length in relation to the lesion under treatment. Following balloon emptying, the distal region resumes the shape shown in Figure 8, whereby the device is easily removed proximally to leave the stenosis implant in place.Figure 10 shows the distal region of an alternative device (80) for deployment of stenosis implant. The device (80) includes an internal catheter (83) with a lumen (84) for guide wire that accommodates a guide wire (86). An external catheter (88) has a catheter lumen (90) that contains the internal catheter. A tubular sheath (92) includes a first end (94) mounted on the distal end (96) of the internal catheter, and a second end (98) mounted on the distal end (100) of the external catheter (88). A radially self-expanding stenotic implant (102) extends ecstatically from the internal catheter, maintaining a state of axially elongated and radially compressed. The device (80) differs mainly from the device (16) in that the external catheter (88) extends distally beyond the internal catheter along the stenosis implant, and thereby cooperates with an internal sheath (104) of the cover to maintain the stenosis implant under radial compression. The sheath (92) is turned back on whether it is to provide a distal turn (106) and a relatively short outer sheath (108) of the sheath. The outer sheath (108) and the inner sheath (104) converge to form the tapered distal end of the device. A dilatation balloon (110) is mounted on the internal catheter (82) near the distal end (96), and is expandable in the same way as the dilatation balloon (58).

When retracted, the external catheter- (88) is positioned prox- imally to the balloon (IOL), so that the sheath (92) once again overlaps and encircles the dilatation balloon to carry out its protective function. . Again, the combined length of the inner and outer sheaths of the sheath, in this case mainly the length of the inner sheath (104), exceeds the distance from the distal end of the inner catheter to the proximal end of the balloon. Another feature of the device (80) refers to the lumen (84) even to the guide wire. The lumen pair-to the guide wire does not travel the length of the internal catheter (82) as before, but ends just proximally to the dilatation balloon (110). An opening (112) through the catheter, open towards the lumen (84), allows the guide wire (86) to exit the internal catheter. An elongated slit (114) through the external catheter (08) extends axially along the external catheter and allows the guide wire to exit the deployment device (80). When the device is in the state of retention of the stenosis implant, the opening (112) of the internal catheter is aligned axially with the distal end of the slit (114). This feature is advantageous for procedures that require short guide threads or one or more guide wire changes, as explained in the PCT application mentioned above, with Publication Number IO 94/15549. Figures 11 and 12 illustrate a sheath (118) of? F¡ retention < the stenosis implant formed according to another alternative embodiment of the invention. The sheath (118) is folded on itself to provide inner and outer sheaths (120) and (122) of the sheath surrounding a radially self-expanding stenosis implant (124) to maintain the stenosis implant in a radially compressed state, axially elongated, against a recovery force. The distal portions of the sheaths (120) and (122) of the sheath converge to provide a tapered distal end (126) terminating at a distal end (128). The proximal end of the inner sheath of the sheath has been mounted on an internal catheter (130), while the proximal end of the outer sheath (122) is attached to an external catheter (132). As before, the outer sheath 122 is mobile proximal to the sheath sleeve 118 from its surrounding position of the stenotic implant, whereby the stenotic implant self-expands progressively radially. Various filaments (134) have been embedded in the sheath (118) and extend radially along the outer sheath (122) of the sheath. The filaments 134 are preferably formed from a fiber with a high modulus of elasticity, such as that sold under the trade name Kevlar or Dacron fibers. The filaments 134 provide rigidity in the axial direction, for improved "pushing" of the device through the artery and other steps.

Figures 13 and 14 illustrate a further embodiment device (140) in which an internal balloon catheter (142) is contained within a lumen (144) of an external catheter (146). The catheter (142) of the balloon includes a lumen for a guidewire. A dilatation balloon (148) is mounted on the catheter- (142) near its distal end, and is in fluid communication with a dilatation lumen of the catheter balloon, through which a pressurized fluid can be delivered. at bal n par-a expand the ball. A tubular sleeve (150) has been fixed to one end (152) Distal external catheter. The opposite end of the sheath has been attached to the catheter (142) of the balloon, but not to its distal extr-emo. Rather, the sheath has been fixed in a proximal position in relation to the balloon (148), as indicated in (154). Accordingly, a substantial portion of the inner sheath (156) of the sheath surrounds the balloon. A portion is far! of the inner envelope extends beyond the distal end (158) of the internal catheter, to surround and contain a stenosis implant (160) in a reduced radially supplied state as described in relation to the device (16). Similarly, the sheath includes an internal sheath wrap (162), and the sheath has been modified to form a distal tip (164) in the manner previously explained. The proxirnal movement of the external catheter (146), in relation to the catheter (142) of the balloon, winds the sheath (150) proximally to free the implant from stenosis (160). As seen in Figure 14, retraction of the sheath exposes the expansion balloon (148), instead of being surrounded by the sheath as in the first embodiment .. The main advantage of this embodiment (Figures 13 and 14 ) consists in that the sheath (150) can have a relatively elastic modulus for confining a radially self-expanding stenosis implant having a high elasticity constant. The sheath does not need to have sufficient elasticity to adapt the expansion of the dilatation balloon in this embodiment. In certain applications, this advantage weighs more heavily than the loss of the sheath as a protective covering heard over the dilatation balloon. If desired, sheaths (92), (118) and (150) may incorporate a controlled rejection of sheath wraps near the distal extremity, as previously explained in relation to Figure 5, to reduce risk of damaging the tissue during the advance of the device to the place of treatment that is intended. The sheaths surround their respective stenosis implants and keep the stenosis implants radially compressed, while in each case an additional axial rigidity is derived from the recovery force of the stenosis implant. Stenosis implants are kept distally from their respective internal catheters, resulting in smaller diameter devices capable of entering arterial passages 2 Narrow, fldicionally to their smaller diameters, the resulting devices present improved pushing and tracking characteristics. If desired, axial rigidity can be increased by a distal extension of the external catheter, or by axial filaments embedded in the runda. Upon release of the stenosis implant from the treatment site, the retracted sheath can encircle the dilatation balloon to provide an additional protective wrapper useful in high pressure angioplasty. Alternatively, the sheath may be subject to a point at which it exposes the dilatation balloon when retracted. The foregoing detailed description and the drawings illustrate and explain several preferred embodiments and are not constructed as limiting the scope of the present invention.

Claims (15)

NOVELTY OF THE INVENTION CLAIMS

1. - A device for deploying an expandable stenosis implant (56, 102, 124, 160) in a treatment site within a body, comprising: a first catheter (28, 82, 130, 142) having a region extreme proxirnal and a distal extreme region; a stenosis implant retaining member (22, 92, 118, 150) disposed in the first rea- son, which extends distally to provide an internal wrapping (46, 104, 120, 156) and which furthermore bends over itself to form an outer wrap (48, 108, 122, 162) adjacent to and on the outside of the inner wrapper, and able to place said inner wrapper in an implant hold position to retain an expandable implant in a "radio" condition. reduced along its axial length; mobile means (34, 44) disposed on the outside of the firstreater (28, 82, 130, 142) and coupled with the outer sheath (48, 108, 122, 162) of the implant retaining member (22, 92, 118) , 150), said movable means operate to move the outer casing in relation to the first catheter and thereby move the inner casing (46, 104, 120, 156) away from the retention position of the implant, thereby releasing the stenosis implant (56, 102, 124, 160) for expansion at the treatment site; characterized also because when the '! ()

Internal wrapping (46, 104, 120, 146) of the implant retaining member (22, 92, 118, 150) is in the retention position: (i) said inner wrapping (46, 104, 120, 156) extends distal to the distal end region of the first catheter (28, 82, 130, 142); (n) said inner wrap (46, 104, 120, 156) also retains the implant (56, 102, 124, 160) distally with respect to the first catheter- (28, 82, 130, 142) to locate a proximal end region of the expandable implant (56, 102, 124, 160) distally of the distal end region of the first catheter; and (ni) said outer layer (48, 108, 122, 162) extends proximally toward the distal end region of the first catheter- (28, 82, 130, 142). 2. The device according to claim 1, further characterized in that said distal end of the first catheter (28, 82, 130, 142) is positioned near the proximal end region of the expandable implant (56, 102, 124, 160) when the inner wrapping (46, 104, 120, 156) of the implant retaining member (22, 92, 118, 150) is in the implant retention position, and is adapted to abut the proximal end region of the implant and thereby avoiding any substantial proxinal migration of the implant as the inner envelope of the implant retaining member moves away from the implant retention position.

3. The device according to claim 1, further characterized in that said member 11 stenosis implant retention (22, 92, 118, 150) is a sheath (22, 92, 118, 150) adapted to encircle a radially self-expandable implant (56, 102, 124, 160) and maintain the implant in a It is radially compressed when it surrounds the implant, and is also adapted to allow the implant to progressively self-expand radially as the sheath separates from its surrounding relationship of the stenosis implant.

4. The device according to claim 3, further characterized in that the first catheter (28, 82, 130, 142) also has a catheter wall defining a lumen for guide wire (30, 84) open to the distal end region, and sheath (22, 92, 118, 150) when in the implant retention position a distal extension of the guidewire lumen (30, 84) is defined.

5. The device of claim 4 further characterized by including: an opening (112) through the wall of the catheter near the distal end, to admit a guide wire to the lumen for the guide wire (30, 84) , so that it moves distally along said distal extension of the lumen for the guide wire (30, 84).

6. The device of claim 3, further characterized in that said sheath (22, 92, 118, 150) comprises a winding membrane, and said inner sheath (46, 104, 120, 156) and outer sheath (48, 108). , 122, 162) are tubular.

7. - The device of claim 6, further characterized in that said inner casings (46, L04, L20, 156) and outer casing (48, 108, 122, 162), when the winding membrane is in the retention state of the implant of stenosis, converge in a distance L direction along the respective distal envelope portions (66, 68) to form a tapered distal end (26, 106, 128, 164) in the winding membrane.

8. The device according to claim 7, further characterized in that the internal wrapper (46, 104, 120, 156) and the outer wrapper (48, 108, L22, 162), in the region of said distal extremity tapering (26, 106, 128, 164) are progressively reduced in the distal direction, whereby the thickness of the distal extremity decreases in the distal direction.

9. The device according to claim 7, further characterized in that the internal envelope (46, 104, 120, 156) and the outer envelope (48, 108, 122, 162) in the region of said distal end (26, 106, 128, 164) provides a transition region over which the hardness of the winding membrane decreases in the distal direction, whereby the extremity is distal! It is softer than the rest of the winding membrane.

10. The device according to claim 1, further characterized by including a reinforcing means (134) extending axially at least along the outer shell (48, 108, 122, 162) to increase axial stiffness of the retention member of the stenosis implant (22, 92, 118, 150).

11. The device according to claim 1, further characterized in that said moving means (34, 44) include a second catheter (18, 88, 132, 146) having a catheter lumen (20, 90, 144) a the substantial length of the entire length thereof, and the first catheter (28, 82, 130, 142) is contained within the lumen of the catheter.

12. The device according to claim 11, further characterized in that said internal wrap (46, 104, 120, 156) and said outer wrap (48, 108, 122, 162) of the implant retaining member (22, 92). , 118, 150) are formed of a tubular winding membrane connected to the first and second catheters in a fluid-tight manner to facilitate the introduction of a fluid through the catheter lumen (20, 90, 144) in a region between the catheter lumen (20, 90, 144). internal and external wrappers.

13. The device according to claim 12, further characterized by including an icpore (69) through said outer shell (48, 108, 122, 162) to allow the release of a fluid from said region to the body .

14. The device according to claim 1, further characterized in that it includes an expansion means (34, 44) mounted on the first catheter (28, 82, 130, 142) near the distal end region thereof.

15. The device according to claim 14, further characterized in that said dilatation means (34, 44) comprise a dilatation balloon (58, 110, 148) and the first catheter (28, 82, 130, 142) includes a balloon dilating lumen (64) open towards an interior of the dilatation balloon. L6. The device according to claim 14, further characterized in that the implant retaining member (22, 92, 118, 150) is mounted on the first catheter (28, 82, 130, 142) at a location distal to the dilation medium (34, 44). 17. The device according to claim 16, further characterized in that the combined axial length of the inner and outer sheaths exceeds an axial distance from said location (54, 96) to a proxirnal end region of the dilatation means (34, 44). ). 18. The device according to claim 14, further characterized in that said implant retaining member (22, 92, 118, 150) is mounted on the first catheter (28, 82, 130, 142) in a proximal location to the means of dilatation (34, 44). 19. The device according to claim 1, further characterized in that said mobile means (34, 44) comprise a second catheter (18, 88, 132, 146) having a proxirnal end region and an end region distal, and a catheter lumen (20, 90, 144) running along the second catheter (18, 88, 132, 146) and opening toward the distal end region of the second catheter, with the first catheter (28, 82, 130 , 142) contained within the catheter lumen; and the stenosis implant retaining member (22, 92, 118, 150) comprises a tubular, foldable and flexible sheath (22, 92, 118, 150) having a first end connected to the first catheter (28, 82, 130 , 142) and a second end connected to the second catheter (18, 88, 132, 146); wherein the first catheter (28, 82, 130, 142) and the second catheter (28, 82, 130, 142) are movable, one in relation to ot or, to place the sheath (22, 92, 118, 150) in the retention position of the implant, and it is also movable to roll the sheath (22, 92, 118, 150) proximally from its surrounding relationship towards the implant, to thereby release the implant for radial expansion at the treatment site. 20. The device according to claim 19, further characterized in that the sheath (22, 92, 118, 150) is connected to the respective ends • Lysters of the first and second catheters in a fluid-tight manner, to facilitate the introduction of a fluid at a location (54, 96) between the inner sheath (46, 104, 120, 156) and the outer sheath (48, 108, 122, 162) by the catheter lumen (20, 90, 144) . 21.- The device in accordance with 3 b claim 17, further characterized in that said winding of the sheath (22, 92, 118, 150) proximally from its surrounding relationship to the implant (56, 102, 124, 160) is achieved by moving the second catheter (18, 88, 132, 146) proximally in relation to the first catheter (28, 82, 130, 142). 22. An apparatus for deploying a radially expandable stenosis implant (56, 102, 124, 160) at a treatment site within a body lumen and forcing the implant against the lumen of the body after deployment; said apparatus comprises: an elongated balloon catheter (28, 82, 130, 142) having a proximal end region and a distal end region; an implant release means (18, 88, 132, 146) disposed along the balloon catheter (28, 82, L30, 142) and having a proximal end region; a sheath (22, 92, 118, 150) and means (34, 44) for connecting an extreme prirner of the sheath to the balloon catheter (28, 82, 130, 142) and connecting a second end of the sheath to the middle of implant release (18, 88, 132, 146); and a flexible dilatation balloon (58, 110, L48) mounted on the balloon catheter (28, 02, 130, 142) near said distal end region of the balloon catheter, and a balloon inflation lumen (64) at along the balloon catheter to deliver fluid under pressure to the dilatation balloon; the sheath (22, 92, 118, 150) is placed in a state of implant retention with the sheath surrounding and encompassing a radial expandable implant (56, 102, 124, 160) along an axial length of the implant when by at least one portion of the implant extends distally from said balloon catheter (28, 82, 130, 142), so as to maintain the implant in a reduced radial state to facilitate the use of the balloon catheter to release the implant. in a treatment site within a body lumen; the implant release means (18, 88, 132, 146) is proximal to the balloon catheter (28, 82, 130, 142) for winding the sheath (22, 92, 118, 150) away from its relation surrounding the implant (56, 102, 124, 160), in order to free the implant for radial expansion at the treatment site; and wherein the first end of the sheath (22, 92, 118, 150) is connected to the balloon catheter (28, 82, 130, 142) in a locator, distal of the dilatation balloon (58, IOL, 148) . 23. A method for deploying an expandable stenosis stenosis implant (56, 102, 124, 160) in a treatment place inside a body, comprising: providing a member (22, 92, 118, 150) attached to a catheter (28, 82, 130, 142) near a distal end thereof, to engage a stenosis implant (56, 102, 124, 160) expandable over a length of the stenosis implant and thereby maintain to the implant of distal stenosis of said distal end in reduced state; With the stenosis implant maintained in a reduced state, supply the stenosis implant with the catheter to a treatment site inside the body, and while keeping the catheter substantially stationary to maintain the stenosis implant in the treatment site and distally of the said distal end, withdraw the limb from its relation of b retention of the stenosis implant, to release the stenosis implant for its expansion at the treatment site. 24. The method of claim 24, further characterized by including after said release and expansion of the stenosis implant (56, 102, 124, 160), move the catheter (28, 82, 130, 142) distally in relation to the stenosis implant until a dilatation balloon (58, 110, 148) mounted near the distal end of the cathe is encircled by the stenosis implant, and then expanding the dilatation balloon to further expand L5 radially the stenosis implant . 25. The method according to claim 2, characterized in that said member comprises a sheath (22, 92, 118, 150) that includes an internal sheath (46, 104, 120, 156) of the sheath extending from this one! 20 outwards from the catheter (28, 82, 130, 142) and surrounding the stenosis implant (56, 102, 124, 160), and that this is turned back on itself to provide a wrapping (48, 108). , 122, 162) that surrounds the inner sheath of the sheath and extends proximally toward the catheter, and wherein said step of withdrawing the limb includes proximally moving the outer sheath to progressively roll the sheath in distancing from its surrounding relationship of stenosis implan. 26. The method according to claim 25, further characterized by including before moving proxirnally the outer shell (48, 108, 122, 162) of the sheath, injecting a fluid into a region between the inner shell (46, 104). , 120, 156) of the sheath and the outer sheath of the sheath, to reduce the friction between said sheaths. 4Ü SUMMARY OF THE INVENTION A device for deploying radially expanding expandable implants and other radially expandable implants, includes an internal catheter, an external catheter that surrounds the internal catheter, and a tubular stenosis implant that retains the sheath formed from a diaphragm membrane. winding; the sheath is bent over itself to provide an internal sheath wrap attached to the internal catheter, and an outer sheath wrap attached to the external catheter; the casings of the sheath extend along and encircle a radially self-expanding stenosis implant, to maintain the stenosis implant distally of the catheter mter-no and in a radially compressed, axially, axially elongated condition; distally of the stenosis implant, the inner and outer sheaths of the sheath converge and taper distally to define a tapered distal extremity. To free the implant from stenosis, the external catheter is moved proximally to wind the membrane away from its surrounding relationship with respect to the stenosis implant, while the stenosis implant progressively self-expands radially, beginning at the distal end; when fully retracted after the release of the stenosis implant, the sheath encircles a distal region of the internal catheter, and can provide a protective sheath between the arterial tissue and a dilatation balloon supported along the distance region L; As an alternative, a stenosis implant formed from a recovery ET can be plastically deformed into a reduced radius state for delivery, which facilitates the use of a more flexible retention sleeve of the stenosis implant. Another alternative includes securing the sheath proxirnally to the dilatation balloon, so that retraction of the sheath leaves the dilatation balloon exposed, instead of being covered by the sheath. P97 / 985F PF / lss- * jh? * Lgrn *