| Devices and methods for controlling expandable prosthesis during develoyment -> Monitor Keywords |
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Devices and methods for controlling expandable prosthesis during develoymentRelated Patent Categories: Prosthesis (i.e., Artificial Body Members), Parts Thereof, Or Aids And Accessories Therefor, Arterial Prosthesis (i.e., Blood Vessel), Stent Combined With Surgical Delivery System (e.g., Surgical Tools, Delivery Sheath, Etc.)Devices and methods for controlling expandable prosthesis during develoyment description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20050288764, Devices and methods for controlling expandable prosthesis during develoyment. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation-in-part of U.S. patent application Ser. No. 10/879,949 (Attorney Docket No. 021629-002700US), filed Jun. 28, 2004, the full disclosure of which is hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] Stents are tubular prostheses designed for implantation in a vessel to maintain patency of the vessel lumen. Stents are used in various vessels throughout the body, including the coronary arteries, femoral arteries, iliac arteries, renal artery, carotid artery, vascular grafts, biliary ducts, trachea, and urethra, to name some examples. Stents are typically implanted by means of long and flexible delivery catheters that carry the stents in a compact, collapsed shape to the treatment site and then deploy the stents into the vessel. In some applications, balloon expandable stents are used. These stents are made of a malleable metal such as stainless steel or cobalt chromium and are expanded by means of a balloon on the tip of the delivery catheter to plastically deform the stent into contact with the vessel wall. In other applications, self-expanding stents are used. These are made of a resilient material that can be collapsed into a compact shape for delivery via catheter and that will self-expand into contact with the vessel when deployed from the catheter. Materials commonly used for self-expanding stents include stainless steel and elastic or superelastic alloys such as nickel titanium (Nitinol.TM.). [0003] While self-expanding stents have demonstrated promise in various applications, such stents face a number of challenges. One such challenge is that in some cases the disease in a vessel may be so extensive that a stent of very long length, e.g. 30-200 mm, is called for. Currently available stents are typically less than 30 mm in length, and suffer from excessive stiffness if made longer. Such stiffness is particularly problematic in peripheral vessels such as the femoral arteries, where limb movement requires a high degree of flexibility in any stent implanted in such vessels. [0004] To overcome the stiffness problem, the idea of deploying multiple shorter stents end-to-end has been proposed. However, this approach has suffered from several drawbacks. First, currently available delivery catheters are capable of delivering only a single stent per catheter. In order to place multiple stents, multiple catheters must be inserted, removed and exchanged, heightening risks, lengthening procedure time, raising costs, and causing excessive material waste. In addition, the deployment of multiple stents end-to-end suffers from the inability to accurately control stent placement and the spacing between stents. This results in overlap of adjacent stents and/or excessive space between stents, which is thought to lead to complications such as restenosis, the renarrowing of a vessel following stent placement. With self-expanding stents the problem is particularly acute because as the stent is released from the catheter, its resiliency tends to cause it to eject or "watermelon seed" distally from the catheter tip by an unpredictable distance. During such deployment, the stent may displace not only axially but rotationally relative to the delivery catheter resulting in inaccurate, uncontrollable, and unpredictable stent placement. [0005] Interleaving stents or stent segments such as those disclosed in co-pending application Ser. No. 10/738,666, filed Dec. 16, 2003, which is incorporated herein by reference, present even greater challenges to conventional delivery systems. Interleaving stents have axially extending elements on each end of the stent that interleave with similar structures on an adjacent stent. Such interleaving minimizes the gap between adjacent stents and increases vessel wall coverage to ensure adequate scaffolding and minimize protrusion of plaque from the vessel wall. However, such interleaving requires that the relative rotational as well as axial positions of the adjacent stents be maintained during deployment to avoid metal overlap and excessive gaps between stents. Conventional delivery systems suffer from the inability to control both the axial and rotational positions of self-expanding stents as they are deployed. [0006] What are needed, therefore, are stents and stent delivery system that overcome the foregoing problems. In particular, the stents and stent delivery systems should facilitate stenting of long vascular regions of various lengths without requiring the use of multiple catheters. Such stents and delivery systems should also provide sufficient flexibility for use in peripheral vessels and other regions where long and highly flexible stents might be required. In addition, the stents and stent delivery systems should enable the delivery of multiple stents of various lengths to one or more treatment sites using a single catheter without requiring catheter exchanges. Further, the stents and stent delivery systems should facilitate accurate and repeatable control of stent placement and inter-stent spacing to enable deployment of multiple self-expanding stents end-to-end in a vessel at generally constant spacing and without overlap. Moreover, the stents and delivery systems should enable the deployment of interleaving stents or stent segments with precision and control over both the axial spacing and rotational position of each stent or segment. BRIEF SUMMARY OF THE INVENTION [0007] The present invention provides prostheses, prosthesis delivery systems, and methods of prosthesis deployment that enable the precise and controllable delivery of multiple prostheses using a single delivery catheter. The prostheses, delivery systems, and methods of the invention provide for the precise control of prosthesis placement so that inter-prosthesis spacing is maintained at a constant and optimum distance. In some embodiments, both axial and rotational displacement of the prostheses relative to the delivery catheter is controlled during deployment, enabling the delivery of multiple prostheses that interleave with one another without overlap. The prostheses, prosthesis delivery systems, and methods of the invention further enable the length of prostheses to be customized in situ to match the length of the site to be treated. The invention is particularly useful for delivery of self-expanding prostheses, but balloon expandable prostheses are also contemplated within the scope of the invention. The invention is well-suited to delivery of stents to the coronary arteries and to peripheral vessels such as the popliteal, femoral, tibial, iliac, renal, and carotid arteries. The invention is further useful for delivery of prostheses to other vessels including biliary, neurologic, urinary, reproductive, intestinal, pulmonary, and others, as well as for delivery of other types of prostheses to various anatomical regions, wherever precise control of prosthesis deployment is desirable. [0008] In a first aspect of the present invention, a prosthesis delivery catheter includes an outer shaft forming a first lumen, a plurality of self-expanding tubular prostheses carried within the first lumen, and a movable coil member interactive with the prostheses to control expansion of the prostheses when the prostheses are deployed from the first lumen. The prostheses are generally adapted to radially expand upon deployment from the first lumen. [0009] In some embodiments, the coil member is removable from the deployed prostheses by rotating the coil member. In some embodiments, the prostheses have sidewalls with a plurality of openings, the coil member being threaded through the openings. Alternatively, the prostheses may include a plurality of struts, at least one of the struts being bent inwardly, with the coil member being threaded through the inwardly bent struts. Optionally, the coil member may be radially expandable to allow controlled expansion of the prostheses. In some embodiments, a distal portion of the coil member is retractable into the outer shaft following deployment of the selected number of prostheses. In some embodiments, the prostheses are disposed within the coil member. [0010] In various embodiments, the coil member may include a plurality of loops forming a helix. For example, in some embodiments between 2 and 6 loops are disposed in each prosthesis. In other embodiments, more than 6 loops are disposed in each prosthesis. In some embodiments, the coil member comprises a plurality of loops contacting each other to form a continuous tube. [0011] Optionally, the delivery catheter may also include a deployment mechanism for deploying a selected number of prostheses from the inner lumen. In some embodiments, for example, the deployment mechanism includes a pushing element slidably disposed in the first lumen, the pushing element being in engagement with at least one of the prostheses to advance the prostheses distally relative to the outer shaft. Optionally, adjacent ends of adjacent prostheses may be interleaved to resist rotation of the prostheses relative to each other. In one embodiment, a distal end of the pushing element is interleaved with a proximal end of a proximal-most prosthesis to resist rotation of the prostheses. In these or other embodiments, the coil member may optionally be configured to maintain rotational position of the prostheses relative to each other. [0012] In another aspect of the present invention, a prosthesis delivery catheter for delivering prostheses into a vessel lumen includes an outer shaft forming a first lumen, an inner shaft slidably disposed within the first lumen, an evertible tube having a first end coupled with a distal end of the outer shaft and a second end coupled with a distal end of the inner shaft, and a plurality of self-expanding tubular prostheses carried within the evertible tube. Again, the prostheses are generally adapted to radially expand upon deployment from the evertible tube. Moving the outer shaft proximally relative to the inner shaft everts a distal portion of the evertible tube so as to deploy one or more of the prostheses. [0013] In some embodiments, an inner surface of the inner shaft comprises at least one adherent element for releasably holding the prostheses to the inner surface. For example, in one embodiment, the adherent element comprises a tacky surface coating. Alternatively, the adherent element may comprise a softenable material into which the prostheses are removably embedded. In other embodiments, the adherent element comprises a plurality of inwardly-facing protrusions positioned to extend through openings in the prostheses. Such protrusions may have any of a number of shapes in various embodiments, such as but not limited to mushroom-shaped, L-shaped, T-shaped, hook-shaped, rounded, spiked, pyramidal, barbed, arrow-shaped or linear. In yet other embodiments, the adherent element may comprise a structure such as but not limited to bumps, bristles, spines, ridges ribs, waves, grooves, pits, channels, detents or random surface irregularities. [0014] In another aspect of the present invention, a method of delivering one or more prostheses to a treatment site in a vessel involves: positioning a delivery catheter at the treatment site, the delivery catheter carrying a plurality of self-expanding prostheses; selecting a desired number of the prostheses to deploy; deploying the desired number of prostheses from the delivery catheter into the vessel, each prosthesis expanding into contact with the vessel upon deployment; controlling axial displacement of each of the selected number of prostheses relative to the delivery catheter during deployment of the prostheses with an expandable coil member coupled with the prostheses; and removing the expandable coil member from the deployed prostheses. [0015] In some embodiments, removing the coil member involves rotating the coil member. For example, the coil member may be helically threaded through the prostheses such that rotating the coil member unthreads the coil member from one or more prostheses. In some embodiments, the method also involves controlling the rotational displacement of the selected number of prostheses relative to the delivery catheter during deployment of the prostheses. In one embodiment, for example, the rotational displacement is controlled by interleaving adjacent ends of adjacent prostheses and interleaving a proximal end of a proximal-most prosthesis with a portion of the catheter device. In some embodiments, a distal portion of the coil member expands with the selected number of prostheses. [0016] In yet another aspect of the present invention, a method of delivering one or more prostheses to a treatment site in a vessel involves: positioning a delivery catheter at the treatment site, the delivery catheter carrying a plurality of self-expanding prostheses within an evertible tube; selecting a desired number of the prostheses to deploy; and everting a distal portion of the evertible tube to deploy the desired number of prostheses from the delivery catheter into the vessel, each prosthesis expanding into contact with the vessel upon deployment. In some embodiments, the distal portion of the evertible tube is everted by sliding an outer shaft of the catheter device relative to an inner shaft of the catheter device. For example, in some embodiments, a distal end of the outer shaft is coupled with a distal end of the evertible tube such that sliding the outer shaft proximally relative to the inner shaft causes the distal end of the evertible tube to bend outward and fold over on itself. [0017] Optionally, the method may further involve controlling axial displacement of each of the selected number of prostheses relative to the delivery catheter during deployment of the prostheses by contacting an adherent inner surface of the evertible tube with the prostheses. In one embodiment, for example, the adherent surface maintains engagement with the prostheses until the distal portion of the evertible tube is peeled away from the prostheses. In some embodiments, the adherent surface comprises a friction-inducing coating or friction-inducing surface feature. In some embodiments, contacting the adherent surface with the prostheses involves releasably coupling one or more retention structures on the inner surface with the prostheses. Alternatively, contacting the adherent surface with the prostheses may involve embedding the prostheses in a deformable material on the adherent inner surface. [0018] In a further aspect of the invention, a prosthesis delivery catheter comprises an outer shaft having a distal end and a first lumen, a plurality of self-expanding tubular prostheses carried within the first lumen, the prostheses being adapted to radially expand upon deployment from the first lumen, and a control member extending distally from the distal end of the outer shaft and defining an interior communicating with the first lumen for receiving one or more of the prostheses. The control member has an undeflected shape when not engaged by one of the prostheses and is configured to deflect radially outwardly when engaged by a prosthesis during expansion thereof. The control member is also configured to resiliently return to the undeflected shape when the prosthesis is removed from the interior. In one embodiment, the control member generally includes a plurality of deflectable tines having free distal ends received within an aperture on the nose cone or nose piece of the catheter. Optionally, the control member may further include a plurality of webs between the tines. In an alternative embodiment, the control member may comprise a distensible tubular structure. [0019] Further aspects of the nature and advantages of the invention will be apparent from the following detailed description of various embodiments of the invention taken in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0020] FIG. 1 is a side cut-away view of a prosthesis delivery catheter according to the invention. Continue reading about Devices and methods for controlling expandable prosthesis during develoyment... Full patent description for Devices and methods for controlling expandable prosthesis during develoyment Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Devices and methods for controlling expandable prosthesis during develoyment patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Devices and methods for controlling expandable prosthesis during develoyment or other areas of interest. ### Previous Patent Application: Custom-length self-expanding stent delivery systems with stent bumpers Next Patent Application: Devices and methods for controlling expandable prostheses during deployment Industry Class: Prosthesis (i.e., artificial body members), parts thereof, or aids and accessories therefor ### FreshPatents.com Support Thank you for viewing the Devices and methods for controlling expandable prosthesis during develoyment patent info. IP-related news and info Results in 0.13455 seconds Other interesting Feshpatents.com categories: Software: Finance , AI , Databases , Development , Document , Navigation , Error 174 |
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