MXPA96005796A - Expandable stent graft covered with polytetrafluoroethylene expand - Google Patents

Abstract

The present invention relates to expandable stent graft generally defines a cylindrical lumen made from a sent having a discontinuous wall that is at least substantially coated with an expanded polytetrafluoroethylene material, the expanded fluoroethylene coating can be a biaxially oriented expanded polytetrafluoroethylene having circumferential longitudinal nodules and fibers or a uniaxially oriented expanded polytetrafluoroethylene material, the expandable stent graft expands and compresses in association with the stent structure as it is contracted and expanded.

Description

IN3ERT0 FI3AD0 EXPANDABLE COVERED WITH EXPANDED POLYTETRAFLUQROETHYLENE This invention claims the benefit of the provisional application of E.U.A. No. 60 / 007,435, entitled: EXPANDIBLE EXPANDIBLE COVERED WITH NON-EXPANDED POLYETHYLFLUOROETHYLENE, filed November 21, 1995.

BACKGROUND OF THE INVENTION The present invention is generally directed to an expandable fixed graft made of a fixative covered with expanded polytetrafluoroethylene. The use of covered expandable fixed grafts for the repair of the body lumen is known in the art. The covered expandable fixed grafts can be implanted in a radially compressed state, generally using a catheter, within blood vessels, urinary tracts, biliary tracts, esophageal, femoralpopiteus, venous, iliac, arterial veins, vena cava, bronchial trachea, abdominal aorta, thoracic aorta, coronary arteries, carotid, colonic arteries, fallopian, eustachian, ureter, urethra, pate or virtually any duct, throat, or any meat of the body in a body. The fixed expandable graft is generally positioned and released from a delivery catheter in a damaged area as desired. The expandable fixated grafts provide external pressure and support the walls of the body lumen, thus creating an improved handle. The addition of a cover in an expandable fixative acts to reduce cell growth or occlusions within the lumen. Covered and expandable covered fasteners that are known in the art are described in the following documents: US patents. Nos. 3,953,566 to Gore; 4,655,771 to Uallstern; 5,061,275 to Ulallsten et al., 5,112,900 to Buddenhagen et al .; 5,123,917 to Lee;: 5,282,823 to Schwartz et al., 5,282,824 to Gianturco, 4,850,999 to Plací--, European Patent Application No. 0 621 015 At a Lukic, European Patent Application No. 0551 179 Al to Palrnaz, DE 391873 -A1 to Vallbracht, Application for Patent Cooperation Treaty UO 95/05131 to Gore, Application for Patent Cooperation Treaty UO 95/05555 to Gore; Application for Patent Cooperation Treaty UO 87/04935 to Fischell. (All documents cited herein, including the foregoing, are included herein in their entirety for all purposes). An object of the present invention is to provide a fixed expandable graft, which is covered, at least in part, with expanded polytetrafluoroethylene (ePTFE). Other objects of the invention will be apparent to those skilled in the art through family planning with the specification and claims herein.

BRIEF DESCRIPTION OF THE INVENTION The fixed expandable graft of the present invention is designed to provide an expanded polytetrafluoroethylene cover that expands and compresses in association with the fixation structure while the fixation structure expands and contracts. The fixed expandable graft of the present invention can be used for repair and support of the vessel walls of the body.

In preferred embodiments of the present invention, an expandable fixed body includes a bonded layer of expanded polytetrafluoroethylene covering a fastener so that the longitudinal fibrils of the cover are at least substantially extended to accommodate expansion. longitudinal, of the fixer when the fixer is radially compressed; the circumferential fibrils are at least substantially bent to accommodate the radial compression of the fixator when the fixator is longitudinally expanded; the longitudinal fibrils are at least substantially bent to accommodate the longitudinal compression of the fixer when the fixer is radially expanded; and also the circumferential fibrils are at least substantially extended to conform to the radial expansion of the fixator when it is longitudinally n r compressed. In other preferred embodiments of the present invention, an expandable fixed graft includes a bonded layer of an expanded polyfluoroethylene shell covering the fixator - so that the nodule distance measured in the longitudinal direction between nodes is increased when the fixed expandable graft is radially compressed; the distance between nodes measured in the longitudinal direction between nodes is decreased when the fixed expandable graft is radially expanded, the distance between nodes measured in the circumferential direction between nodes is increased when the fixed expandable graft is longitudinally compressed, and also the distance between nodes. nodule measured in The circumferential direction between nodules is decreased when the fixed expandable graft is longitudinally expanded. In summary, the present invention relates to an expandable prosthesis having a) a discontinuous wall defining a lumen adapted to assume a longitudinally contracted position and a longitudinally expanded position; and b) at least one layer of expanded filled polytetra luoroe having a first longitudinal average distance between nodes in a free state, the polytetrafluoroethylene layer is fixed to the wall so that it has a second average longitudinal distance between nodes when the wall is in the longitudinally contracted position, the second average longitudinal distance between nodes is less than the first average longitudinal distance between nodes. The expanded polytetrafluoroeti layer can have i) an average longitudinal distance between nodules of between 0 and almost 50 microns, preferably in ro 5 and almost 45 or between 20 and almost 30 microns, when the wall is in the longitudinally contracted position, and n) an average longitudinal distance between nodes between almost 50 and almost 150 microns, preferably between almost 60 and almost 14 or between almost 80 and almost 120 microns, when the wall is in the longitudinally expanded position. The present invention also relates to an expandable prosthesis having a) a discontinuous wall defining a lumen adapted to assume a radially contracted position and a radially expanded position; and b) at least one tubular layer of an expanded polytetrafluoroethylene having a first cycunferential distance When the average between nodes in a free state, the polytetrafluoroethene layer is fixed to the wall so that it has a second average circumferential distance between nodes when the wall is in the radially contracted state, the second average circumferential distance between nodes is 0 less than the first average circumferential distance between nodes. The tubular layer of expanded polytetrafluoroethylene can have i) an average circumferential distance between nodes of between almost 0 and almost 75 microns, preferably between almost 5 and almost 70 or between almost 20 and almost 50 microns, when the wall is in the position radially contracted, and n) an average circumferential distance between nodes of between almost 75 and almost 150 microns, preferably between almost 80 and almost 140 microns or in re almost 80 and almost 120 microns, when the wall is in the radially expanded position. The present invention also relates to an expandable prosthesis having a) a discontinuous wall generally defining a lumen adapted to assume a longitudinally expanded position and a longitudinally contracted position; and b) at least one layer of expanded filled polytetrafluoroet having a first average longitudinal distance between nodes in a free state, the polyfluoroethylene layer is fixed to the wall so that the polytetrafluoroethene has a second average longitudinal distance between nodes of between 0 and 99% of the first longitudinal longitudinal distance between nodes when the wall is in the longitudinally contracted position. The second average longitudinal distance between nodes can be between almost 20 and almost 50% of the first average longitudinal distance between nodes when the wall is in the longitudinal position with frayed. The present invention also relates to an expandable prosthesis having a) a discontinuous wall defining a lumen adapted to assume a radially expanded position and a radially contracted position; and b) at least one expanded polytetrafluoroethylene layer having a first average cycunferential distance between nodes, and a first average cicunference distance between nodes in a free state, the poly tetrafluoroethylene layer is fixed to the even wall that is have a second average circumferential distance between nodes of between 0 and 99% of the first average longitudinal distance between nodes when the wall is in the radially expanded position and a second average circumferential distance between nodes less than almost 50% of the first average circumferential distance between nodules when the wall is in the radially contracted position. The second average longitudinal distance between nodes can be between almost 20 and almost 50% of the first average longitudinal distance between nodes, and the second average circumferential distance between nodes can be-less than about 25% of the first circumferential distance between nodes when the wall is in the radially contracted state. The present invention also relates to an expandable prosthesis having a) a discontinuous wall defining a lumen adapted to assume a radically expanded position and a radially contracted position; and b) at least one layer of expanded polyfluoroethylene having a first average longitudinal distance between nodes in a book state, the polytetrafluoroethylene layer is fixed to the wall so that the polytetrafluoroethylene has a second average longitudinal distance between nodes in between. 0 and 99% of the first average longitudinal distance between nodules when the wall is in the radial position being expanded and a second average circumferential distance between nodes less than almost 50% of the first average circumferential distance between columns when the wall is in position radially contracted. The second average longitudinal distance between nodes can be between almost 20 and almost 50% of the first average longitudinal distance between nodes, and the second average circumferential distance between nodes may be less than almost 25% of the first circumferential distance between nodes. The present invention also relates to an expandable fixed graft having a) a braided self-expanding fixator characterized by a longitudinal shortening on radial expansion from a first length of longitudinal fastener to a second length of longitudinal fastener; and b) at least one tubular layer of biaxially oriented expanded polytetrafluoroethylene consisting of fixed nodes and fibrils to the fixative, characterized by a shortening of an average longitudinal distance between nodes on radial expansion from a first average longitudinal distance between nodes to a second average longitudinal distance between nodes; further characterized in that the ratio of the first length of longitudinal fastener to the second length of longitudinal fastener is within about 25% of, and is substantially substantially the same as, the ratio of the first longitudinal average distance between nodes to the second average distance between nodules. The present invention also relates to an expandable fixed graft having a) a braided self-expanding fixator characterized by a longitudinal shortening on radial expansion; b) at least one layer of expanded polytetrafluoroethylene um axially oriented to the fixative, the polytetrafluoroethylene wood characterized by having substantially no nodule. The present invention also relates to a method for manufacturing an expandable prosthesis that includes a) providing a self-expanding braided fastener having a longitudinal orientation in a partially radially expanded state; b) providing at least one layer of expanded polyfluoroethanol having a longitudinal orientation and a first longitudinal average distance between nodes in a free state; c) longitudinally compressing the expanded polyurethane 1 uretile layer so that the resulting longitudinally compressed layer has a second median longitudinal nodal distance that is less than the first average longitudinal distance between nodes; and d) fixing the longitudinally compressed layer of the expanded polyfluoroethanol to the self-expanding braided fastener in a state at least partially radially expanded so that the longitudinal orientations of the fixator and the expanded polyfluoroethane layer correspond to each other substantially. BRIEF DESCRIPTION OF THE DRAWINGS The following features, objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, especially when considered in conjunction with the accompanying drawings in which: Figure 1 shows a micrographic view showing the nodules and fibrils of a biaxially expanded polytetrafluoroethylene material oriented to a 2000X amplification. Figure 2 shows an illustration of the nodule of the nodule-fibril relationship and the distances between nodes of a biaxially oriented expanded polytetrafluoroethylene material in a fixator that is longitudinally compressed. Figure 3 is a view of the nodule of the fibril nodule relationship and the distances between nodes of a biaxially oriented expanded polytetrafluoroethylene material in a fixator that is radially compressed. Figures 4-12 illustrate the steps for making a fixed expandable graft in accordance with the present invention, wherein: Figure 4 illustrates a screw; Figure 5 shows biaxially oriented expanded polytetrafluoroethylene material (ePTFE) (tube, sheet or strips of any combination of tube, sheet or strips) covering at least partially the screw; Figure 6 shows the ePTFE material longitudinally compressed within the screw and further illustrates the longitudinal fibrils being substantially bent and the circumferential fibrils substantially extended; Figure 7 shows an expanded fixator, having an inner diameter greater than the combined outer diameter of the spindle and the ePTFE material, being positioned on the ePTFE material longitudinally compressed in the spindle; Figure 8 shows a sectional view of the fixator on the longitudinal ePTFE material of tablet; Figure 9 shows an end view of the fastener-on the longitudinally compressed ePTFE material; Figure 10 shows an outer layer of longitudinally compressed ePTFE material placed on the fixer, an inner layer of longitudinally compressed ePTFE material and the spindle; Figure 11 shows a sectional view of an outer layer * of an ePTFE material longitudinally compressed on the fixer and an inner layer (ePTFE material longitudinally compressed) The ePTFE materials are bent over or through the outer surface, surface inside or through the discontinuous wall of fixative, and Figure 12 shows an end view of an outer layer-of finally compressed ePTFE material seated on the fixator and an inner layer of longitudinally compressed ePTFE material.The ePTFE materials are bent over or through of the outer surface, inner surface or through a discontinuous wall of the fixator Figure 13 shows an illustration of various states of the ePTFE in the fixator as when the fixed expandable graft is radially compressed or radially expanded.

DESCRIPTION OF THE PREFERRED MODALITIES Referring now to Figures 1-3, the present invention relates to a generally cylindrical and flexible expandable fixated graft 20 which can be made of a fixator-12 and a cover of biaxially oriented expanded polytetrafluoroethylene material 3. The polytetrafluoroethylene material Biaxially oriented expanded 3 has a microstructure consisting of nodes 2 and fibrils 4,4 'and distances between nodes oc, a', Q_, Q '. The term "biaxial expanded polytetrafluoroethylene material" as used herein means a biaxially oriented expanded polytetrafluoroethylene material. The term uniaxial expanded polytetrafluoroethylene material as used herein means that the uniaxially oriented expanded polytetrafluoroethylene material. The longitudinal average nodule distance between biaxially or uniaxially expanded polytetrafluoroethylene can be between almost 5 and almost 150 microns in the free state, preferably between 20 and almost 60 micras in the free state. The longitudinal orientation and distances between resultant longitudinal nodes are based on the orientation when the expanded polytetrafluoroethylene is placed in a fixer, so that the longitudinal orientation of the fixator and expanded polytetrafluoroethylene substantially correspond to each other. Expanded polytetrafluoroethylene is in a free state when no force is applied thereto. A preferred embodiment of the fixed expandable graft of the present invention can be designed so that its expanded polytetrafluoroethylene cover 1.0 'is associated with expansion or compression of the fixator 12 (FIG. 13), while the fixed graft 20 is inserted into a delivery catheter. or it is displayed inside the lumen of the body. The expandable fixed graft 20 is designed to repair and support the walls of the body vessels. A preferred embodiment of the fixed expandable graft 20 of the present invention can be made of a braided fixer 12 such as that described in the US patent. No. 5,061,275 to Wallsten. Such a self-expanding fixator is characterized in that the fixator contracts longitudinally while radially expanding, and longitudinally expanding while contracting radially. Other non-braided fasteners are known in the art which share this feature. This fixture 12 may be at least partially covered, individually or in combination, with at least one layer of tube, sheet, strip or film of biaxial expanded polytetrafluoroethylene material 10 on the inner surface 14, outer surface 18, inner surface 14 and outer surface 18, between the inner surface-14 and the outer surface 18 of the discontinuous wall of a fastener 12 (Figures 7-13). The fixative 12 and the expanded polytetrafluoroethylene cover 10 'can be joined together, for example under heat and pressure, to form the fixed expandable graft 20. Another method of joining can include the use of another polymer such as polyethane or FEP which has a lower melting point. The expandable fixed graft 20 of the present invention offers the properties of a fixative 12 and the benefits of an expanded polytetrafluoroethylene covering that conforms to the docility and distortion of the underlying fixative 12. The expanded polytetrafluoroethylene microstructure (Figures 1.-3) and its orientation in the fixer 12 (Figures 5-13) refers to the present invention. The expandable fixed graft 20 has characteristics that could reduce occlusion of the lumen and improve healing of damaged body loops. Another preferred embodiment of the expandable fin graft 20 of the present invention may consist of a uni-axial expanded polytetrafluoroethylene shell on at least part of the inner surface inner surface 14, outer surface 18, inner surface 14 and outer surface 18, between the inner surface 14 and the outer surface 18 of the fixer 12. The uniaxial expanded filled poly etrafluoroe cover can consist substantially of fibrils while the nodes have been substantially reduced to zero. Other unilaxial expanded polyurethane luoroeti covers may have discrete nodules so that the nodes are substantially unconnected with each other. Another preferred embodiment of the expandable fixed graft 20 of the present invention may consist of a uniaxial expandable polytetrafluoroethylene shell and a biaxially extended polytetrafluoroethylene shell 10 'on at least part of the inner surface 14, outer surface 18, inner surface 14 and surface outer 18, or between the inner surface 14 and the outer surface 18 of the fastener 12. The cover of polytetraf! Uniaxial expanded uoroethylene consists of a substantial fibrillar body and is longitudinally oriented on the fixator. In these preferred modalities, the expanded poly-fluoroethylene cover can be correspondingly expanded against that with the fixator 12. Since longitudinal or radial forces are not applied to the fixed expandable graft (FIG. 13), the relationship between nodule and fibril can change within the material of biaxial expanded polyfluoroethylene 10 'and the fibril ratio within the uniaxial expanded polytetrafluoroethylene material and allows the shell to conform to the shape of the fixed 12. Figure .1.3 illustrates an attached expandable graft of the present invention with the portions extremes in at least partially radially expanded state and the middle section in a state at least partially radially contracted. In the preferred embodiments of the expandable fixed graft of the present invention, the preferred ratio between nodule and fibril the biaxial expanded polytetrafluoroethylene or the preferred fibril ratio of the uniaxial expanded polytetrafluoroethylene material depends on the dimensions of the fastener 12 that is covered. However, the relationship between the preferred nodule and fibril of biaxial expanded polytetrafluoroethylene in the binder state or the preferred fibril ratio of uniaxial expanded polytetrafluoroethylene in the free state may have a circumferential fibril length in the range of from 5 microns to almost 150 microns.; a distance between n dulos measured in the circumference that is in the scale of from 5 microns to almost 150 micras; a length of longitudinal fibrilla on the scale from 5 microns to almost 100 microns; at a distance between nodes measured in the longitudinal direction in the range of from 5 microns to almost 100 microns which is sufficient to offer the desired scale of performance for the present invention. The nodes 2 and fibrils 4, 4 'within the biaxial expanded polytetrafluoroethylene material can be oriented on the fixer 12 so that the longitudinal fibrils are at least substantially extended 4' to accommodate the longitudinal expansion of the fixator 12, when the fixator- 12 is radially compressed; the circumferential fibrils are at least substantially folded 6 'to accommodate the radial compression of the fixator when the fastener 12 is longitudinally expanded; the longitudinal fibrils are at least substantially bent 4 to accommodate longitudinal compression of the fastener 12 when the fastener 12 is radially expanded; or the circumferential fibrils are at least substantially extended 6 to adapt to the radial expansion of the fixator with the fixator-12 this longitudinally compressed (figures 6, 7, 10 and 13). The interaction of nodes 2 and fibrils 4, 4 'within the biaxial expanded polytetrafluoroethylene material 10' allows biaxial expanded polytetrafluoroethylene material .1.0 'to substantially adapt to the shape of the longitudinal and radial compression and expansion of the fixator 12. The present invention also relates to a method for joining an expanded polytetrafluoroethylene material 10, 10 'on a fixator 12 so that the distance between nodes measured in the longitudinal direction between nodes increases when the fixed expandable graft 20 is radially compressed; the distance between nodes measured in the longitudinal direction between nodules decreases when the fixed expandable graft 20 is radially expanded; the distance between nodules measured in the circumferential direction between nodes 2 increases when the fixed expandable graft 20 is longitudinally compressed; or the distance between nodes measured in the circumferential direction between nodes 2 decreases when the fixed expandable graft is longitudinally expanded. The fixer 12 and the expanded polytetrafluoroethylene cover 10 'are substantially bonded together and substantially and coextensively compress, expand or adapt in one way, when radial and longitudinal forces expand or compress the fixed expandable graft 20. For example, the fixed graft Expandable can compress when inserted into a catheter or the expandable fixed graft 20 can expand when it is removed from the catheter-within a body vessel. The cover of biaxial expandable polytetrafluoroethylene 1.0, 10 'or uniaxial expanded polytetrafluoroethylene are not elastorial, but each expands and contracts with the forces of compression and longitudinal and radial expansion in the fixed expandable graft 20. Also the covers of expanded polytetrafluoroethylene biaxial or uniaxial expanded polytetrafluoroethylene can expand and compress the expanded fixed graft 20 and have folds, folds, blisters or reduced kinks, thereby reducing the thrombogenic effect that may result from uneven or rough vessel surfaces. The orientation of the ePTFE and the interaction of the nodes 2 and fibrils 4, 4 ', 6, 6' can allow the inner surface 14 and / or the outer surface 18 to be sub-substantially smooth in both contracted and expanded states. Another preferred embodiment of the expandable fixed graft 20 of the present invention offers a substantially smooth cover during compression and radial and longitudinal expansion of the fixed expandable graft 20. The radial compression and longitudinal expansion of the expanded fixed graft 20 occurs when it is inserted into a catheter. The radial expansion and longitudinal compression of the fixed expandable graft 20 occurs when it is inserted into several vessels of the body. The expandable fixed graft 20 of the present invention can provide a surface that promotes increased fluid flow., reduced fluid turbulence, and improved deformation properties in general when compared to conventional covered fasteners. Many of the features of the present invention are desired by medical practitioners in the repair and healing of body vessels. When compared to an uncovered fixer 12, the expanded polytetrafluoroethylene cover in the fixed 1.2 requires little additional force to expand or contract. The biaxial expanded polytetrafluoroethylene 10 'material or uniaxial expanded polytetrafluoroethylene material are substantially adapted to the average radial and longitudinal compression and expansion of the fixator 12. The expanded polytetrafluoroethylene cover is designed to improve the benefits of a conventional fixator 12 by adding various capacities, without, reducing the deformation or performance of the fixed expandable graft 20. The expandable fixed graft 20 is generally in the form of a cylindrical lumen having a discontinuous wall covered with expanded polytetrafluoroethylene. A preferred embodiment of the fixed expandable graft of the present invention has a nodule-fibril ratio in the biaxial expanded polytetrafluoroethylene 10 'shell or a fibril ratio in the uniaxial expanded polytetrafluoroethylene shell, respectively, so that the fixed, expandable graft 20 longitudinally expand up to 300% when it is radially compressed compared to its length when it is in an expanded radially expanded state. Another preferred embodiment of the expandable graft of the present invention has a nodule-fibril ratio in the biaxial expanded polytetrafluoroethylene 10 'shell or a fibril ratio in the uniaxial expanded polytetrafluoroethylene shell so that the fixed expandable graft 20 radially expands to 1000 % of the measurement of its complete diameter and radially compressed.

Other preferred embodiments of the expandable fixed graft 20 of the present invention may consist of at least a biaxial expanded polytetrafluoroethylene or uniaxial expanded polytetrafluoroethylene 10 'partial layer or a biaxial expanded polytetrafluoroethylene 10 combination and uniaxial expanded polytetrafluoroethylene material. The uniaxial expanded polytetrafluoroethylene material has a fibril ratio and is substantially composed of fibrils while the nodes 2 have been substantially reduced to almost 0. Each layer of biaxial or uniaxial expanded polytetrafluoroethylene material can have a thickness of from 10 to 500. u and can be made of tubes, sheets, films, or a plurality of strips disposed on the interior surface 14 of the discontinuous wall, exterior surface 18 of the discontinuous wall of the fixator or between the interior surface 14 and exterior surface 18 of the discontinuous wall of the fixer 12 including the limits between the grids of the walls. The discontinuous wall and the expanded polytetrafluoroethylene material are bonded at a temperature range of from 340 ° C to 390 ° C. In another embodiment of the expandable fixed graft 20 of the present invention, the discontinuous wall of the fixator 12 may be coated with expanded polytetrafluoroethylene polytetrafluoroethylene or both expanded polytetrafluoroethylene and polytetrafluoroethylene on at least part of its surface. 92 Preferred embodiments of the expandable fixed graft 20 of the present invention can be produced by the method of placing a biaxial expanded polytetrafluoroethylene material 10 in a spindle 8 in at least a partially expanded state, and subsequently longitudinally compressing the expanded polytetrafluoroethylene material. biaxial 10 while this is positioned on the spindle 8 so that the longitudinal fibrils are at least substantially bent -4 and the circumferential fibrils are at least substantially extended 6 so that the distance between nodes measured in the longitudinal direction between the nodes 2 is decreased and the distance between nodes measured in the circumferential direction between nodes 2 is increased. A fastener 12 having a larger internal diameter than the combined diameter of the expanded polytetrafluoroethylene material and the spindle 8 is subsequently placed on the outer surface of the expanded polytetrafluoroethylene material. The contact is then maintained between the fixative and the expanded polytetrafluoroethylene material while the cover and the fixer are heated to a temperature in the range from 340 ° C to almost 390 ° C for a time of from one minute to 15 minutes. minutes to attach the expanded polytetrafluoroethylene material to the discontinuous wall of the fixator. The expandable fixed graft is subsequently cooled and removed from the spindle.

Additionally, preferred embodiments of the fixed expandable graft of the present invention can also be produced by the method of placing a biaxial expanded polytetrafluoroethylene material on a spindle and subsequently expanding or longitudinally stretching the biaxial expanded polytetrafluoroethylene material while it is poled on the spindle so that the longitudinal fibrils are at least substantially extended and the circumferential fibrils are at least substantially bent. Also, the distance between nodes measured in the longitudinal direction between nodes 2 can be increased and the distance between nodes measured in the circumferential direction between the nodes 2 can be decreased. A fixator having a larger diameter than the combined diameter of the expanded polytetrafluoroethylene material and the spindle is then placed on the outer surface of the expanded polytetrafluoroethylene material. The fixed expandable graft is radially compressed and the contact is then maintained between the fixed and the expanded polytetrafluoroethylene material while the coating and the fixed are heated to a temperature ranging from about 340 ° C to about 390 ° C for a time varying from about 1 minute to about 15 minutes to join the expanded polytetrafluoroethylene material to the discontinuous wall of the fixed. The fixed, expandable graft is then cooled and removed from the spindle.

The preferred embodiment of the fixed expandable graft of the present invention can also be produced by longitudinally compressing the expanded polytetrafluoroethylene material before the. step of placing the expanded polytetrafluoroethylene material in the spindle. The preferred embodiment of the expandable fixed graft of the present invention can also be produced by longitudinally expanding or narrowing the expanded polytetrafluoroethylene material before the step of placing the expanded polytetrafluoroethylene material in the spindle. One type of expanded polytetrafluoroethylene can be rolled diagonally under tension to at least at least partially expanded. Additional compressible and expandable objects of varying size, size, shape may also be able to take advantage of the expanded polytetrafluoroethylene coatings. This invention has been described herein in considerable detail to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use said specialized components as required. However, it should be understood that the invention can be carried out by means of specifically different equipment and devices, and that various modifications, in terms of equipment details and procedures, can be achieved without departing from the scope of the invention. Therefore, the spirit and scope of the claims should not be limited to the description of the preferred versions contained herein.

Claims (21)

NOVELTY OF THE INVENTION CLAIMS

1. - An expandable prosthesis comprising: (a) a discontinuous wall defining a lumen adapted to assume a longitudinally contracted position and a longitudinally expanded position; and (b) at least one layer of expanded polytetrafluoroethylene having a first average longitudinal internodule distance in a free state, the polytetrafluoroethylene layer fixed to the wall so that it has a second average longitudinal internodule distance when the wall is in the wall. longitudinally contracted position, the second average longitudinal internodule distance being less than the first average longitudinal internodule distance.

2. ~ The prosthesis in accordance with the claim 1, further characterized in that the expanded polytetrafluoroethylene layer has (i) an average longitudinal internodule distance between about 0 and about 50 microns when the wall is in the longitudinally contracted position, and (ii) an average longitudinal internodule distance between about of 50 and approximately 150 microns when the wall is in the longitudinally expanded position.

3.- The prosthesis in accordance with the claim 2, further characterized in that the expanded polytetrafluoroethylene layer has (i) an average longitudinal internodule distance when the wall is in the longitudinally contracted position between about 5 to about 45 microns.

4.- The prosthesis in accordance with the claim 3, further characterized in that the expanded polytetrafluoroethylene layer has (i) an average longitudinal internodule distance when the wall is in the longitudinally contracted position between about 20 and about 30 microns.

5. The prosthesis according to claim 2, further characterized in that the layer of expanded polytetrafluoroethylene has (ii) an average longitudinal internodule distance when the wall is in the longitudinally expanded position between about 60 and about 140 microns.

6. The prosthesis according to claim 5, further characterized in that the expanded polytetrafluoroethylene layer has (ii) an average longitudinal internodule distance when the wall is in the longitudinally expanded position between about 80 and about 120 microns.

7. An expandable prosthesis comprising: (a) a discontinuous wall defining a lumen adapted to assume a radially contracted position and a radially expanded position; and (b) at least one tubular layer of an expanded polytetrafluoroethylene having a first average circumferential internodule distance in a free state, the polytetrafluoroethylene layer fixed to the wall so that it has a second average circumferential internodule distance when the wall is in the radially contracted state, the second average circumferential internodule distance being less than the first average circumferential internodule distance.

8. The prosthesis according to claim 7, further characterized in that the tubular layer of expanded polytetrafluoroethylene has (i) an average circumferential internodule distance between about 0 and about 75 microns when the wall is in the radially contracted position, and (ii) an average circumferential internodule distance between about 75 and about 150 microns when the wall is in the radially expanded position.

9. The prosthesis according to claim 8, further characterized in that the tubular layer of expanded polytetrafluoroethylene has (i) an average circumferential internodule distance between about 5 and about 70 microns when the wall is in the radially contracted position.

10. The prosthesis according to claim 9, further characterized in that the tubular layer of expanded polytetrafluoroethylene has (i) an average circumferential internodule distance between about 20 and about 50 microns when the wall is in the radially contracted position. .

11. The prosthesis according to claim 8, further characterized in that the tubular layer of expanded polytetrafluoroethylene has (ii) an average circumferential internodule distance between about 80 and about 140 microns when the wall is in the radially expanded position.

12.- The prosthesis in accordance with the claim 11, further characterized in that the tubular layer of expanded polytetrafluoroethylene has (ii) an average circumferential internodule distance between about 80 and about 120 microns when the wall is in the radially expanded position.

13. A spastic prosthesis comprising, (a) a discontinuous pair-ed defined generally a lumen adapted to assume a longitudinally expanded position and a longitudinally contracted position and (b) at least one layer of expanded polytetrafluoroethylene having a prirner distance between average longitudinal nodules in a free state, the polytetrafluoroethylene layer attached to the wall so that the polytetrafluoroethylene has a second longitudinal longitudinal nodule distance between 0 and 99% of the first longitudinal distance between nodes when the par-ed is in the position contracted longitudinally.

14. - The prosthesis in accordance with the claim 13, characterized in that the second average longitudinal nodule distance is between about 20 and 50% of the first longitudinal nodule distance when the par-ed is in the longitudinally contracted position.

15. An expandable prosthesis comprising (a) a discontinuous pair-ed that generally defines a lumen adapted to assume a radially expanded position and a radially contracted position and (b) at least one layer of expanded polytetrafluoroethylene having a first distance between average circumferential nodes in a free state, the polytetrafluoroethylene layer attached to the wall so that the polytetrafluoroethylene has a second average circumferential nodule distance less than about 50% of the first average circumferential nodule distance when the wall is in the wall. position contracted longitu in 1mente.

16. The prosthesis of claim 15, characterized in that the second distance between average circumferential nodes is less than about 25% of the first average circumferential nodule distance when the pair-ed is in the radially contracted position.

17. An expandable prosthesis comprising (a) a discontinuous wall defining a lumen adapted to assume a radially expanded position and a radially contracted position; and (b) at least one layer of polytetrafluoroethylene having a first average longitudinal nodule distance and a first average circumferential nodule distance in a free state, the polytetrafluoroethylene layer attached to the wall so that the polytetrafluoroethylene has a second distance between longitudinal nodules between 0 and 99% of the first distance between average longitudinal nodules when the wall is in the radially expanded position and a second average circumferential nodule distance less than about 50% of the first distance between average circumferential nodules when the wall is in the radially contracted position.

18. The prosthesis according to claim 17, characterized in that the second distance between average longitudinal nodes is between 20 and 50% approximately of the first distance between average longitudinal nodules, and the second distance between nodes ci average reference is less than 25 Approximately% of the first distance between the average circumferential nodes.

19. An injectable expandable fixer comprising (a) a self-expanding fastener between the lacing characterized by a longitudinal decrease in radial expansion from a first length of longitudinal fastener to a second length of longitudinal fastener; and (b) at least one tubular layer of biaxially oriented expanded polytetrafluoroethylene comprising nodules and fibrils attached to the fixator characterized by a decrease in the longitudinal longitudinal nodal distance in radial expansion from a first distance between longitudinal longitudinal nodules to a second distance between longitudinal longitudinal nodules; characterized in that the ratio of the first length of the longitudinal fastener to the second length of the longitudinal fastener is about 25% of the ratio of the primary irradiation between longitudinal nodules to the second average nodule distance.

20. An expandable fixative graft comprising (a) a self-expanding fixator between laces characterized by a longitudinal decrease in radial expansion; (b) at least one layer of expanded polytetrafluoroethylene oriented uniaxially attached to the fixative, polytetrafluoroethylene characterized in that it has substantially nodules.

21. A method of fabricating an expandable prosthesis comprising (a) provides a self-expanding interlock fastener having a longitudinal orientation in a state at least partially radially expanded; (b) providing at least one layer of expanded polytetrafluoroethylene having a longitudinal orientation and a first distance between average longitudinal nodes in a free state; (c) longitudinally compressing the polytetrafluoroethylene layer such that the resultant longitudinally compressed layer has a second average longitudinal nodule distance that is less than the first average longitudinal nodal distance; and (d) securing the longitudinally compressed layer of expanded polytetrafluoroethylene to the self-expanding snap fastener in the at least radially expanded state so that the longitudinal orientations of the binder and the expanded polytetrafluoroethylene layer correspond substantially to each other.