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  Tubular prosthesis for external agent deliveryUSPTO Application #: 20060161247Title: Tubular prosthesis for external agent delivery Abstract: A tubular prosthesis, which may be an endovascular prothesis, is provided which includes a tubular member (stent or stent/graft combination) and an outer covering having portions sealed to the tubular member. The tubular member is impervious to a pre-determined fluid, particularly an occluding fluid, while the outer cover is pervious to the pre-determined fluid. In one aspect of the present invention, the implantation of the prosthesis allows for occluding fluid to weep from the prosthesis and into a sac of an aneurysm to cause occlusion thereof without introducing the occluding fluid into the blood stream. In this manner, a Type II failure of the prosthesis may be avoided. In other aspects of the invention, therapeutic agents may be delivered and/or a seal may be formed about the prosthesis to prevent a Type I failure. (end of abstract) Agent: Hoffmann & Baron, LLP - Syosset, NY, US Inventor: John E. Sherry USPTO Applicaton #: 20060161247 - Class: 623001440 (USPTO) Related Patent Categories: Prosthesis (i.e., Artificial Body Members), Parts Thereof, Or Aids And Accessories Therefor, Arterial Prosthesis (i.e., Blood Vessel), Having Plural Layers The Patent Description & Claims data below is from USPTO Patent Application 20060161247. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a divisional application of U.S. application Ser. No. 09/978,988, filed on Oct. 16, 2001, now allowed, the entire contents of which are hereby incorporated by reference. FIELD OF THE INVENTION [0002] This invention relates to tubular prostheses, including, but not limited to, endovascular grafts and stent/grafts, for maintaining patency of blood vessels and treating aortic artery aneurysms, and tubular conduits for maintaining patency in other bodily passageways. BACKGROUND OF THE PRIOR ART [0003] It is known in the prior art to use endovascular prostheses to treat aortic artery aneurysms ("AAA"). Such treatment includes implanting a stent, or stent/graft, within the diseased vessel to by-pass the anomaly. An aneurysm is a sac formed by the dilation of the wall of the artery, which may be congenital, but usually is caused by disease and, occasionally, by trauma. With reference to FIG. 1, sac 1 of aneurysm A is defined by dilated portions 2 of aortic artery AA. With the collection of blood and other embolic material in the sac 1, and being subjected to hemodynamic pressure, the aneurysm A may rupture, if untreated, causing internal bleeding. [0004] Techniques had been developed in the prior art where diseased portions of a blood vessel, such as with an aneurysm, were ablated and replaced with a prosthetic member, such as that shown in U.S. Pat. No. 4,938,740 to Melbin. This technique, however, required open surgery. As an improvement over this technique, endovascular emplacement techniques have been developed to implant grafts and stent/grafts into a vessel from a remote puncture site, thereby obviating the need for open surgery. For example, as shown in FIG. 1, an endovascular prosthesis 3 (stent or stent/graft) is positioned to by-pass the aneurysm A with ends 4, 5 of the prosthesis being in contiguous contact with healthy portions of the aortic artery AA, the prosthesis 3 having been introduced endovascularly (e.g. with a catheter). Accordingly, if the aneurysm A was to rupture, blood flow through the aortic artery AA would be uninterrupted, and internal bleeding generally avoided. [0005] Although considerable success has been enjoyed with stent and stent/graft performance, failures have been noted and predominantly classified in four classes: Types I-IV. Type I failures relate to leaks (referred to as endoleaks) between the vascular prosthesis and the vessel wall. For example, with reference to FIG. 1, a Type I failure would be blood weeping about the end 4 of the prosthesis 3 into the sac 1. [0006] A Type II failure involves blood flowing into the aneurysm sac through collateral arteries. Again, with reference to FIG. 1, the sac 1 may be in fluid communication with blood vessels BV, other than the aortic artery AA. Typically, lumbar arteries are in fluid communication (directly or indirectly) with an aneurysm sac. Because blood flow out of the sac 1 is prevented, hemodynamic pressure away from the sac 1 is not present. However, because of hemodynamic pressure within blood vessels in communication with the sac 1, blood flow, nevertheless, is directed into the sac 1 (as shown by arrows). A technique has been developed in the prior art which calls for embolizing the blood vessels BV, such as with embolus coils, thereby isolating the sac 1 from collateral blood flow. However, an additional procedure would be required for embolization. [0007] A Type III failure is a mechanical failure, wherein a hole may be ripped into the prosthesis (e.g., excessive wear at a metal/non-metal (fabric or polymer) interface) or poor integrity exists at a connection, or connections, between modular components of a prosthesis, (e.g., extensions may be connected to the prosthesis to obtain improved securement in one or both of the iliac arteries.) For example, as shown in FIG. 1, a hole 6 may be torn into the prosthesis 2, or poor sealing is obtained at the connection between the prosthesis 3 and an extension 7. [0008] A Type IV failure relates to excessive prosthesis porosity, wherein blood seeps through the prosthesis regardless of the integrity of sealing and mechanical connections. [0009] As can be readily appreciated, even with the successful implantation of an endovascular prosthesis, failures may occur thereafter. It has been found that Type II failures are most prevalent, and may effect up to 30% of all implanted prostheses. Accordingly, there is a clear need for an endovascular prosthesis which can reduce the likelihood, and ideally eliminate, Type II failures. SUMMARY OF THE INVENTION [0010] To overcome deficiencies in the prior art, a tubular prosthesis is provided that includes a tubular member, which is impervious to a pre-determined fluid, and an outer covering, which is pervious to the pre-determined fluid. Accordingly, in one aspect of the invention, the prosthesis may be an endovascular prosthesis, and a fluid, which is effective for occluding the sac of an aneurysm, may be introduced by the prosthesis into a space between the tubular member and the outer covering. The fluid will transmit through the outer covering and weep into the sac to cause at least partial occlusion thereof without the occluding fluid being introduced into the blood stream. In this manner, collateral blood flow may be prevented from flowing into the aneurysm sac and collecting therein. [0011] A fluid conduit, preferably a microcatheter, is connected to the endovascular prosthesis so as to be in fluid communication with the space defined between the tubular member and the outer covering. It is preferred that the fluid conduit be connected to the prosthesis prior to introduction into the body, with such connection continuing through deployment of the prosthesis and engagement with the vessel. Prior to withdrawal of the deployment device used to implant the prosthesis (e.g. an introducer catheter), occluding fluid is injected through the fluid conduit and between the tubular member and the outer cover with an effective amount of fluid being introduced to achieve at least partial occlusion of the aneurysm sac. With the outer cover being pervious to the fluid, the fluid transmits therethrough. Upon the effective dose having been injected into the space, the fluid conduit is caused to detach from the prosthesis, and withdrawn with any deployment device, such as a guidewire. [0012] The tubular member may be of any endovascular prosthetic construction known in the prior art, including graft and stent/graft configurations (including single layer and multi-layer grafts and stent/grafts). The tubular member may be a textile graft, a polymeric graft, or a combination thereof. In addition, the tubular member may have a stent reinforcement (single stent or multiple stents), such stent being self-expanding or expandable by a distensible member, such as a balloon. [0013] The outer covering may be formed of a textile, a polymeric film, or a combination thereof. In addition, the outer covering may be made pervious to the occluding fluid through inherent porosity of the constituent material of the outer covering (e.g., porosity of expanded polytetrafluoroethylene (ePTFE)), and/or, more preferably, through cut apertures physically defined in the outer covering. To attempt to achieve even distribution of the occluding fluid, it is desired to make the outer covering increasingly pervious to the fluid at locations further from the fluid conduit. [0014] The occluding fluid is preferably a liquid embolic, which may be an alginate, an hyaluronic acid, and/or a cyanoacrylate, or an admixture thereof. Alternatively, a sclerosing agent may be used, as well as cross-linking polymers (polyurethanes, silicones), thrombin, and autologous clot(s). The occluding fluid may be in a liquid state or a gel, and may be formed with solids in a suspension of either state (liquid or gel). [0015] In another aspect of the invention, therapeutic agents, with or without the occluding fluid, may be transmitted via the subject invention. [0016] The tubular prosthesis may be used as an endovascular prosthesis, as well as, in other applications to maintain patency of a bodily passageway, such as the esophagus, trachea, colon, biliary tract, urinary tract, prostate, and brain. [0017] These and other features of the invention would be better understood through a study of the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS [0018] FIG. 1 is a schematic of an aortic artery aneurysm with an endovascular prosthesis by-passing thereby; [0019] FIG. 2 shows a first embodiment of a tubular prosthesis of the subject invention; Continue reading... Full patent description for Tubular prosthesis for external agent delivery Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Tubular prosthesis for external agent delivery 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 Tubular prosthesis for external agent delivery or other areas of interest. ### Previous Patent Application: Stent for high frequency thermotherapy Next Patent Application: Medical device with leak path Industry Class: Prosthesis (i.e., artificial body members), parts thereof, or aids and accessories therefor ### FreshPatents.com Support Thank you for viewing the Tubular prosthesis for external agent delivery patent info. 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