the prosthesis of the preferred embodiment of the present invention is a composite implantable intraluminal prosthesis which is particularly suited for use as a vascular graft . the composite prosthesis of the present invention includes a graft structure with circumferentially distensible support structure and a noncontinuous layer of wound ptfe components . desirably , the composite may also include a continuous eptfe layer , with the circumferentially distensible support structure interposed between these ptfe layers . the present description is meant to describe the preferred embodiments , and is not meant to limit the invention in any way . shown in fig1 is a longitudinally discontinuous tubular ptfe body , shown generally at 2 , which forms one of the layers of the composite . the tubular body is formed by wrapping at least two ptfe components , such as strips 3 , 4 , in opposed spirals , about a distensible tubular support structure shown generally at 5 , or directly around a mandrel m , to form a tubular body 2 without a seam . the tubular body may consist of any number of ptfe components spirally wound around the mandrel , to form a longitudinally non - continuous tubular body . when desired , the non - continuous layer may be wound about the support structure as shown in fig2 . alternatively , the support structure may be used as a mandrel , for forming the non - continuous ptfe tubular body . continuous , as used herein , refers to a tubular structure whose surface extends substantially uninterrupted throughout the longitudinal length thereof . in the case of an extruded tube , the tubular structure is completely uninterrupted . in the case of a sheet formed tube there are no transverse interruptions . as is known in the art , a substantially uninterrupted tubular ptfe structure exhibits enhanced strength and sealing properties when used as a vascular graft , but little radial or axial compliance . [ 0023 ] fig2 depicts a tubular body where strips 3 and 4 are interwoven through each other according to the present invention atop the circumferentially distensible support structure , or stent 5 . distensible , as used herein , refers to a stent which may be expanded and contracted radially . the stent , 5 , may be fastened to the non - continuous tubular body , or simply assembled therewith to form a composite structure , with a stent side and a ptfe side . a three layer composite prosthesis may be made by ( pre ) adding a continuous eptfe tubular body , as shown at 7 in fig4 . alternatively , the non - continuous layer may be formed on the mandrel ( i . e . fig1 or 3 ), the support structure placed thereon , and a non - continuous or a continuous ptfe layer placed atop the support structure . in constructing the longitudinally non - continuous tubular body of the present invention it is not necessary for the components to be of similar width , or wound with the same number of turns per inch , or in the same direction . various stent types and stent constructions may be employed in the invention . among the various stents useful include , without limitation , self - expanding stents and balloon expandable stents . the stents may be capable of radially contracting , as well , and in this sense can best be described as radially distensible or deformable . self - expanding stents include those that have a spring - like action which causes the stent to radially expand , or stents which expand due to the memory properties of the stent material for a particular configuration at a certain temperature . nitinol is one material which has the ability to perform well while both in spring - like mode , as well as in a memory mode based on temperature . other materials are of course contemplated , such as stainless steel , platinum , gold , titanium and other bicompatible metals , as well as polymeric stents . the configuration of the stent may also be chosen from a host of geometries . for example , wire stents can be fastened into a continuous helical pattern , with or without a wave - like or zig - zag in the wire , to form a radially deformable stent . individual rings or circular members can be linked together such as by struts , sutures , welding or interlacing or locking of the rings to form a tubular stent . tubular stents useful in the present invention also include those formed by etching or cutting a pattern from a tube . such stents are often referred to as slotted stents . furthermore , stents may be formed by etching a pattern into a material or mold and depositing stent material in the pattern , such as by chemical vapor deposition or the like . the circumferentially tubular distensible support structure , or stent , may be formed of an elongate wire , helically wound , which may be compacted with the non - continuous tubular body to form a radially expandable stent composite . the stent may be of the type described in u . s . pat . no . 5 , 575 , 816 to rudnick , et al . the distensible support structure , or stent , may be either of the balloon - expanded or self - expanded type . stents of this type are typically introduced intraluminally into the body , and expanded at the implantation site . [ 0027 ] fig3 shows an alternate assembly wherein the ptfe components 3 , 4 , and 6 are assembled on the mandrel in multiple passes . as shown , the last pass winds component 6 over the opposed winding of components 3 and 4 . any number of components may be used to form the non - continuous tubular bodies . the windings are made helically , in any direction , along the mandrel or support structure . the mandrel may be constructed of segments for ease of heat sealing the composites . [ 0028 ] fig4 depicts a desired embodiment of the present invention in which incorporates a continuous tubular inner body 7 . this embodiment employs a non - continuous tubular body 2 of opposed wound or interwoven ptfe components . the woven or braided configuration may be two dimensional or may be three dimensional , as shown in fig5 and 6 . [ 0029 ] fig5 shows two ptfe components , such as ptfe strips , or pre - manufactured ptfe tapes combined in a two dimensional matrix , wherein the tapes comprise the separate components of the non - continuous tubular body 2 . the e . g . tapes may be interwoven closely , as shown in fig5 . in addition , closely woven tapes , filaments or strips may be used to form larger strips which may be used as components of the non - continuous tubular body . [ 0030 ] fig6 shows an enlarged view of a three dimensional thread comprised of three ptfe filaments braided together to form a three dimensional threads which may form the components of non - continuous tubular body . such braided knitted or woven construction provides axial and radial compliance to the prosthesis by defining spaces within the braided , knitted or woven or extruded structure . in certain applications where enhanced sealing properties are required , a sealant 28 , as shown in fig6 may be interspersed within the woven or braided components to create a non - porous tubular body . sealants which may be used in the prosthesis include fep , polyurethane , and silicone . additional sealants include biological materials such as collagen , and hydrogels , polymethylmethacrylate , polyamide , and polycarbonate . elastomers as sealants will have less impact on flexibility . a suitable sealant provides a substantially sealed outer tube without significantly reducing longitudinal and axial compliance . as shown herein the braided longitudinally non - continuous tubular body shown in the above - referenced figures form non - continuous bodies comprised of ptfe components tubularly assembled . the non - continuous structure of the braided tubular body provides the composite prosthesis with enhanced radial and longitudinal , or axial compliance . the radial and axial compliance can , in fact , be varied with the different non - continuous ptfe bodies which may be used , as may be suitable for the use of the intraluminal prosthesis . the non - continuous layer 2 is formed by wrapping one , two , or three , or more ptfe tapes about , or through , each other . in preferred embodiments the ptfe components are pre - manufactured tape of expanded ptfe ( eptfe ), the term expanded refers to ptfe which has been stretched uniaxially , biaxially , or multiaxially in a particular direction . the ptfe tape of the prosthesis of the present invention is typically stretched in the longitudinal direction of the tape . when two or more tapes are combined to form the braided body , the resultant tubular body possesses a biaxial , or multiaxial resultant orientation in the aggregate . because eptfe exhibits increased strength in the direction of its stretching , the eptfe tubularly assembled body exhibits the advantage of the increased strength of a biaxial or multiaxial stretched film , but exhibits the advantages of compliance because of its non - continuous surface . in another embodiment , ptfe filaments may be wound about a mandrel or support structure to form the non - continuous tubular body . the continuous ptfe tubular layer may be bonded to the non - continuous ptfe tubular layer through spaces in the open wall of the stent . the bonding may be effectuated with the use of an adhesive , or by adhering the layers together without an adhesive . bonding of the ptfe layers without an adhesive may take place by such methods as laminating , or sintering of the prosthesis . furthermore , the stent may be adhered to the continuous ptfe tubular layer , the braided ptfe tubular layer , or both . similarly , such adherence may take place with or without the use of an adhesive . although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings , it is to be understood that the invention is not limited to those precise embodiments , and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention .
a composite stent - graft tubular prosthesis includes a non - continuous tubular body formed of polytetrafluoroethylene components , providing axial and circumferential compliance to said prosthesis and a circumferentially distensible stent .