US20190160208A1

US20190160208A1 - Armored graft material structure and method

Info

Publication number: US20190160208A1
Application number: US16/142,545
Authority: US
Inventors: Keith Perkins; Zachary Borglin; Julie BENTON; Matt Petruska; Darren Galligan; Samuel Robaina; Rajesh Radhakrishnan
Original assignee: Medtronic Vascular Inc
Current assignee: Medtronic Vascular Inc
Priority date: 2017-11-28
Filing date: 2018-09-26
Publication date: 2019-05-30
Also published as: EP3716905A1; US10939990B2; WO2019108511A1; US10856965B2; WO2019108523A1; EP3943045A1; WO2019108485A1; US20190159882A1; US20190159883A1; EP3716902A2; US20190159881A1; EP3716908A1; EP3716906A1; EP3943045B1; WO2019108527A1; US20190159884A1; EP3716904A1; WO2019108496A2; EP3716906B1; WO2019108499A1

Abstract

The techniques of this disclosure generally relate to applying an armor coating to a graft material. The armor coating is armor, impermeable to fluid, and elastic. The armor coating seals openings within the graft material eliminating passage of fluid through the graft material.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 62/591,601, filed on Nov. 28, 2017, entitled “ADVANCED GRAFT MATERIALS FOR ENDOVASCULAR APPLICATIONS” of Borglin et al., which is incorporated herein by reference in its entirety.

FIELD

The present technology is generally related to an intra-vascular device and method. More particularly, the present application relates to a device for treatment of intra-vascular diseases.

BACKGROUND

A conventional stent-graft typically includes a radially expandable reinforcement structure, formed from a plurality of annular stent rings, and a cylindrically shaped layer of graft material defining a lumen to which the stent rings are coupled. Stent-grafts are well known for use in tubular shaped human vessels.
To illustrate, endovascular aneurysmal exclusion is a method of using a stent-graft to exclude pressurized fluid flow from the interior of an aneurysm, thereby reducing the risk of rupture of the aneurysm and the associated invasive surgical intervention.
A type IV endoleaks occurs when fluid passes through the graft material of the stent-graft. There are various causes of type IV endoleaks including leaks though pores of the graft material, through suture openings, tears, or other openings in the graft material.

SUMMARY

The techniques of this disclosure generally relate to applying an armor coating to a graft material. The armor coating is armor for the graft material, impermeable to fluid, and elastic. The armor coating seals openings, e.g., pores and suture openings, within the graft material eliminating passage of fluid through the graft material and type IV endoleaks.
In one aspect, the present disclosure provides a prosthesis including a graft material having a variable permeability and an armor coating on the graft material. The armor coating is impermeable to fluid.
In another aspect, the disclosure provides a prosthesis including a graft material having a suture opening. Stitching extends through the suture opening. An armor coating seals the suture opening.
In yet another aspect, the disclosure provides a method including applying an armor coating to a graft material including sealing openings between filaments of the graft material with the armor coating.
The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of an armored stent-graft in accordance with one embodiment.

FIG. 2 is an enlarged plan view of a region II of a transition zone of a graft material of the stent-graft of FIG. 1 in accordance with one embodiment.

FIG. 3 is a cross-sectional view of the stent-graft of FIG. 2 along the line in accordance with one embodiment.

FIG. 4 is an enlarged plan view of a region IV of the stent-graft of FIG. 1 in accordance with one embodiment.

FIG. 5 is a cross-sectional view along the line V-V of stitching of the stent-graft of FIG. 4 in accordance with one embodiment.

FIG. 6 is an enlarged plan view of a stitched seam of an armored stent-graft in accordance with one embodiment.

FIG. 7A is a cross-sectional view along the line VII-VII of the stent-graft of FIG. 4 in accordance with one embodiment.

FIG. 7B is a cross-sectional view along the line VII-VII of the stent-graft of FIG. 4 in accordance with another embodiment.

DETAILED DESCRIPTION

FIG. 1 is a perspective view of an armored stent-graft 100, e.g., an abdominal aortic stent-graft, in accordance with one embodiment. Stent-graft 100, sometimes called a prosthesis, includes a graft material 102 and one or more stent rings 104. Illustratively, stent rings 104 are self-expanding stent rings, e.g., nickel titanium alloy (NiTi), sometimes called Nitinol, or self-expanding members. The inclusion of stent rings 104 is optional and in one embodiment stent rings 104 are not included. In another embodiment, stent rings 104 are balloon expandable stents.
In accordance with this embodiment, graft material 102, sometimes called a textile, includes a proximal opening 106 at a proximal end 108 of graft material 102. In accordance with this embodiment, graft material 102 further includes a pair of distal openings 110, 112 at a distal end 114 of graft material 102.
As used herein, the proximal end of a prosthesis such as stent-graft 100 is the end closest to the heart via the path of blood flow whereas the distal end is the end furthest away from the heart during deployment. In contrast and of note, the distal end of the catheter is usually identified to the end that is farthest from the operator (handle) while the proximal end of the catheter is the end nearest the operator (handle).
For purposes of clarity of discussion, as used herein, the distal end of the catheter is the end that is farthest from the operator (the end furthest from the handle) while the distal end of stent-graft 100 is the end nearest the operator (the end nearest the handle), i.e., the distal end of the catheter and the proximal end of stent-graft 100 are the ends furthest from the handle while the proximal end of the catheter and the distal end of stent-graft 100 are the ends nearest the handle. However, those of skill in the art will understand that depending upon the access location, stent-graft 100 and the delivery system descriptions may be consistent or opposite in actual usage.
Graft material 102 and more generally stent-graft 100 includes at least three zones 116, 118, 120 in accordance with this embodiment. Proximal zone 116 extends from proximal end 108 to transition zone 118. Transition zone 118 extends from proximal zone 116 to leg zone 120. Leg zone 120 extends from transition zone 118 to distal end 114.
Proximal zone 116 is cylindrical having a substantially uniform diameter D although varies in diameter in another embodiment. Proximal zone 116 includes a longitudinal axis L. Leg zone 120 includes a pair of legs 124, 126 extending from transition zone 118 to distal openings 110, 112, respectively.
Transition zone 118 is a region which transitions from the larger diameter D of proximal zone 116 to legs 124, 126 of leg zone 120. Transition zone 118 varies in diameter from diameter D at proximal zone 116 to a smaller diameter D1 at leg zone 120.
A main lumen 128 is defined by graft material 102 at proximal zone 116 and transition zone 118. Main lumen 122 extends generally parallel to longitudinal axis L and between proximal opening 106 and legs 124, 126 of stent-graft 100.
Legs 124, 126 extend from transition zone 118 to distal openings 110, 112 of legs 124, 126, respectively. Legs 124, 126 define branch lumens 130, 132, respectively. Main lumen 128 is bifurcated into branch lumens 130, 132, e.g., for an abdominal aortic aneurysm (AAA) repair. Although a bifurcated stent-graft 100 is illustrated and discussed, in other embodiments, stent-graft 100 includes a single lumen, various lumens, or other configurations, e.g., tubular for thoracic applications or multi-limbed for branching applications.
Graft material 102 includes an inner surface 134 and an opposite outer surface 136. Outer surface 136 is sometimes called an abluminal surface and inner surface 134 is sometimes called a luminal surface.
In one embodiment, graft material 102 is hydrophobic, e.g., is polyester terephthalate (PET), expanded polyester terephthalate (ePET), or other graft material or textile. In one embodiment, graft material 102 includes filaments which are woven, knitted, sewn, or otherwise combined to create graft material 102. In one embodiment, filaments are long string like members, sometimes called threads, fibers, or yarns. Due to this combining of filaments to form graft material 102, there are inherent spaces, sometimes called pores, created between the filaments. Fluid can pass through these spaces, creating type IV endoleaks.
In one embodiment, the permeability of graft material 102 varies in zones 116, 118, 120. For example, in transition zone 118, the permeability of graft material 102 is greater than the permeability of graft material 102 in proximal zone 116 and leg zone 120. Illustratively, in transition zone 118, filaments are removed to allow transition zone 118 to narrow from diameter D to diameter D1. Further, due to the narrowing of transition zone 118, the combining of threads is irregular leading to a greater porosity.
FIG. 2 is an enlarged plan view of a region II of transition zone 118 of graft material 102 of stent-graft 100 of FIG. 1 in accordance with one embodiment. Referring now to FIGS. 1 and 2 together, graft material 102 includes a plurality of filaments 202. Filaments 202 are illustrated as including a plurality of vertical filaments 202V and a plurality of horizontal filaments 202H interlaced with one another. This arrangement of filaments 202 is illustrative only and in light of this disclosure those of skill in the art will understand that filaments 202 can be combined in any one of a number of different fashions to form graft material 102.
Regardless of the manner of combination of filaments 202, a plurality of openings 204 are formed within graft material 102 between filaments 202, openings 204 sometimes being called pores of graft material 102. Openings 204 entirely through graft material 102 and between inner surface 134 and outer surface 136.
In accordance with this embodiment, openings 204 are defined by filaments 202. For example, a single opening 204A of the plurality of openings 204 is defined by a space between two adjacent vertical filaments 202V and two adjacent horizontal filaments 202H. The other openings 204 are defined in a similar manner. Openings 204 are formed due to the overlapping nature of filaments 202 and the inherent inability to make filaments 202 completely flush with one another along the entire length of filaments 202.
Although one example of openings 204 is set forth, openings 204 can be created in any one of a number of ways. For example, openings 204 are a defect in graft material 102, a tear, a rip, a puncture, or other imperfection.
FIG. 3 is a cross-sectional view of stent-graft 100 of FIG. 2 along the line III-III in accordance with one embodiment. Referring now to FIGS. 2 and 3 together, graft material 102 including openings 204 is illustrated. In accordance with this embodiment, an armor coating 302 is applied to graft material 102.
Armor coating 302 is armor for graft material 102, e.g., is a protective covering for graft material 102. Armor coating 302 enhances the durability, abrasion resistance, and impermeability of graft material 102. Armor coating 302 adheres to the material of graft material 102, e.g., polyester terephthalate (PET), expanded polyester terephthalate (ePET), or other graft material or textile. Armor coating 302 is impermeable to fluid in accordance with this embodiment. In one embodiment, armor coating 302 is hydrophobic although in other embodiments, armor coating is not hydrophobic, e.g., is hydrophilic.
Armor coating 302 has elasticity, i.e., is made of an elastic material. Armor coating 302 is durable, for example, can last for several years inside the human body, as a permanent part of stent-graft 100. Further, armor coating 302 is abrasion resistant, for example, resists abrasion from micro motion of another structure such as a stent-ring 104 thereon or sutures therethrough or during packing or other handling. In one embodiment, armor coating 302 is a polymer coating, e.g., a non-degrading elastomeric material such as polyurethane (PU).
In accordance with this embodiment, armor coating 302 includes an outer coating 304, an inner coating 306, and a filling coating 308. Outer coating 304 is applied to outer surface 136 of graft material 102. Inner coating 306 is applied to inner surface 134 of graft material 102. Filling coating 308 fills any openings, including openings 204, in graft material 102 and extends between inner surface 134 and outer surface 136.
Although armor coating 302 includes outer coating 304, inner coating 306, and filling coating 308 in the embodiment illustrated in FIG. 3, in other embodiments, armor coating 302 includes one or more of outer coating 304, inner coating 306, and filling coating 308. For example, armor coating 302 includes outer coating 304 only and inner coating 306 and filling coating 308 are not formed. In yet another example, armor coating 302 includes inner coating 306 only and outer coating 304 and filling coating 308 are not formed. In yet another example, armor coating 302 includes inner coating 306 and outer coating 304 only and filling coating 308 is not formed. In yet another example, armor coating 302 includes inner coating 306 and filling coating 308 only or outer coating 304 and filling coating 308 only.
Armor coating 302 is applied using any one of a number of techniques in accordance with various embodiments. For example, armor coating 302 is applied by spraying, coating, dip coating, and/or brushing. In one embodiment, armor coating 302 is vacuum applied, i.e., a vacuum is formed within graft material 102 which draws (sucks) armor coating 302 into openings 204. In yet another embodiment, armor coating 302 is applied by electro spinning, i.e., using electric force to draw armor coating 302 into openings 204. Although a few examples are provided, armor coating 302 can be applied in a variety of different techniques in accordance with different embodiments.
In yet another embodiment, armor coating 302 is selectively applied to various zones of stent-graft 100. In one embodiment, armor coating 302 is applied to transition zone 118 only. As discussed above, transition zone 118 is a region of graft material 102 that has increased permeability to fluids. In one embodiment, transition zone 118 spans an aneurysm. Accordingly, armor coating 302 is applied to transition zone 118 to make transition zone 118 impermeable. This reduces and essentially eliminates fluid leaks through transition zone 118, e.g., type IV endoleaks.
By eliminating type IV endoleaks, classification of periprocedural endoleak types is easier, e.g., Type I and Type II endoleaks are easier to discern. For example, graft material 102 has inconsistent permeability along the length of stent-graft 100, e.g., in transition zone 118, which absent armor coating 302 would manifest as a focal leak point that could require treatment. In one embodiment, armor coating 302 prevents pressurization of the aneurysm sac allowing the aneurysm sac to shrink leading to a better outcome and lower intervention rate.
However, armor coating 302 is not applied to proximal zone 116 and leg zone 120. In one embodiment, proximal zone 116 and leg zone 120 contact a vessel(s) and are sometimes referred to as seal zones. Accordingly, impermeability of proximal zone 116 and leg zone 120 is not as essential and so armor coating 302 is not applied thereto. Further, by leaving proximal zone 116 and leg zone 120 without armor coating 302, sometimes called as native graft material 102, tissue is allowed to grow into openings 204 thus preventing endoleaks and migration of stent-graft 100.
In another embodiment, armor coating 302 is applied to specific portions of stent-graft 100, such as the seal zone, e.g., proximal zone 116 and/or leg zone 120. For example, armor coating 302 is applied to specific portions to adjust/change properties along the length of stent-graft 100.
In another embodiment, armor coating 302 is applied to the entire graft material 102 including proximal zone 116, transition zone 118, and leg zone 120. For example, armor coating 302 is applied prior to assembly, i.e., graft material 102 is coated with armor coating 302 prior to making stent-graft 100, to reduce manufacturing defects such as runs and suture hole size because the sutures and filaments 202 are held in the intended configuration. This, in turn, may reduce the number of rejected stent-grafts.
Graft material 102 including armor coating 302 applied thereto is referred to as an armored graft material 140. Armored graft material 140 is well-suited to accept stitching as discussed below in reference to FIGS. 4 and 5.
FIG. 4 is an enlarged plan view of a region IV of stent-graft 100 of FIG. 1 in accordance with one embodiment. FIG. 5 is a cross-sectional view along the line V-V of stitching 402 of stent-graft 100 of FIG. 4 in accordance with one embodiment.
Referring now to FIGS. 1, 4 and 5 together, armor coating 302 is applied to graft material 102 in at least proximal zone 116, although may also be applied to graft material 102 in transition zone 118 and leg zone 120. Accordingly, proximal zone 116 includes armored graft material 140 in accordance with this embodiment.
Stent-ring 104 is coupled to armored graft material 140 in proximal zone 116 with stitching 402, sometimes called sutures 402. Generally, stitching 402 wraps over stent ring 104 and passes through armored graft material 140 including armor coating 302 and graft material 102. In one embodiment, stitching 402 is applied by piercing armored graft material 140 with a needle to which stitching 402 is connected.
Stitching 402 is a plurality of individual stitches separated from one another in one embodiment. In another embodiment, stitching 402 is a single piece that is repeatedly passed through graft material 102. Stitching 402 is a string like member, e.g., a suture, as those of skill in the art will understand in light of this disclosure.
As illustrated in FIG. 5, stitching 402 creates an opening 404, sometimes called a suture opening 404 in graft material 102. Stitching 402 extends through suture opening 404. Suture opening 404 has a diameter D2 greater than a diameter D3 of stitching 402. Accordingly, absent armor coating 302, fluid could leak between graft material 102 and suture 402 through opening 404.
However, armor coating 302 is elastic and stretches around stitching 402 and seals suture opening 404. This behavior of armor coating 302 is sometimes called an elastomeric material recovery property of armor coating 302. Accordingly, fluid is prevented from leaking through suture opening 404 and between stitching 402 and graft material 102.
Further, armor coating 302 is resilient and adds strength to graft material 102 such that micro motion of stitching 402 does not tear graft material 102 or increase the size (diameter) of suture opening 404. For example, pulsation of fluid, e.g., blood, causes micro motion of stitching 402 and armor coating 302 reduces this micro motion by holding stitching 402 in place.
Absent armor coating 302, tension in stitching 402 can shift filaments 202 of graft material 102 resulting in suture runs that increase the permeability of graft material 102. This is especially true when graft material 102 is low profile, i.e., thin. Armor coating 302 prevents stitching 402 from shifting filaments 202 and the associated increase in permeability of graft material 102.
Although stitching of stent-ring 104 to armored graft material 140 is discussed and illustrated in reference to FIGS. 1, 4 and 5, in other embodiments, other structures are stitched to armored graft material 140. Armor coating 302 prevents leaks through suture openings 404 and adds strength to graft material 102 as discussed above.
For example, back-table modifications (modification made by the physician directly for example in the hospital) are made to armored stent-graft 100 by the physician. Armor coating 302 prevents leaks through the new holes created during the back-table modification process due to the elastomeric material recovery properties of armor coating 302 and adds strength to graft material 102 as discussed above. Another example of stitching through armored graft material 140 is discussed below in reference to FIG. 6.
FIG. 6 is an enlarged plan view of a stitched seam 602 of an armored stent-graft 600 in accordance with one embodiment. Stent-graft 600 of FIG. 6 is similar to stent-graft 100 of FIG. 1 and only the significant differences are discussed below.
Referring now to FIG. 6, stitched seam 602 is a region where armored graft material 140 is sewn to itself or to another structure. For example, a single piece of armored graft material 140 is wrapped into a cylindrical shape and sewn at stitched seam 602 with stitching 402. Stitching 402 holds stitched seam 602 together.
In accordance with this embodiment, FIG. 5 is representative of a cross-section view along the line V-V of FIG. 6. Armor coating 302 prevents leaks through suture opening 404 and adds strength to graft material 102 as discussed above.
FIG. 7A is a cross-sectional view along the line VII-VII of stent-graft 100 of FIG. 4 in accordance with one embodiment. In FIG. 7A, armor coating 302 is applied to graft material 102 prior to attachment of stent-ring 104. Accordingly, stent-ring 104 contacts armor coating 302 instead of graft material 102.
In accordance with this embodiment, armor coating 302 protects graft material 102 from abrasion from stent-ring 104. For example, micro motion of stent-ring 104 causes stent-ring 104 to rub on armor coating 302. As armor coating 302 is resilient, armored coating protects graft material 102 from abrasion. Further, in one embodiment, armor coating 302 is elastic and absorbs/minimizes micro motion of stent-ring 104.
FIG. 7B is a cross-sectional view along the line VII-VII of stent-graft 100 of FIG. 4 in accordance with another embodiment. In FIG. 7B, armor coating 302 is applied to graft material 102 after attachment of stent-ring 104, e.g., after stent-graft 100 is manufactured. Accordingly, stent-ring 104 is covered by armor coating 302 and stent-ring 104 is interposed between graft material 102 and armor coating 302.
In accordance with this embodiment, armor coating 302 adheres stent-ring 104 to graft material 102. Armor coating 302 eliminates, or at least minimizes, micro motion of stent-ring 104 relative to graft material 102. By eliminating the micro motion between graft material 102 and stent-ring 104, armor coating 302 prevents abrasion of graft material 102 from stent-ring 104. Further, to the extend suture openings such as suture opening 404 of FIG. 5 are created during manufacturing, these suture openings are sealed by armor coating 302.
As set forth above, armor coating 302 improves the durability of graft material 102 and generally of stent-graft 100. Accordingly, stent-graft 100 is well suited for use with younger patients, e.g., in situations where stent-graft 100 must last a long time such as greater than 10 years.
Referring again to FIG. 3, in one embodiment, the thickness T of graft material 102 is reduced by armor coating 302. In one embodiment, absent armor coating 302, providing graft material 102 with a low profile, e.g., thickness T, is unsatisfactory due to acute permeability and diminished material strength of graft material 102. As armor coating 302 imparts resilience and impermeability to graft material 102, graft material 102 can be provided with a minimal thickness T. Stated another way, armor coating 302 allows for profile reduction, i.e., thinning of graft material 102 as the base material and replenishing the loss of mechanical properties with armor coating 302.
For example, thickness T of graft material 102 is less than 0.11 millimeter (mm). In one particular embodiment, thickness T of graft material 102 is with the range of less than 0.11 mm to 0.05 mm. In one embodiment, armored graft material 140, i.e., graft material 102 and armor coating 302 combined, is thinner than graft material used in typical stent-graft applications allowing for delivery system profile reduction.
In another embodiment, the textile structure, e.g., graft material 102, is chosen to determine the amount of coating present in stent-graft 100, e.g., as an additional design parameter such as spacer textiles.
Referring still to FIG. 3, in one embodiment, outer coating 304 and/or inner coating 306 are selected to engineer tissue response on outer surface 136 and/or inner surface 134. This depends on the properties of the coating agent or any bioactive agents included in outer coating 304 and/or inner coating 306. Engineered tissue responses include antimicrobial, anti thrombogenic, anti-inflammatory, for example, through passivation, and/or endothelialization and/or active inhibition. Accordingly, armor coating 302 provides inflammatory passivation, fights infection and/or reduces intraluminal thrombus in various embodiments.
Further, in one embodiment, outer coating 304 is of a different material than inner coating 306, e.g., to optimize the different surfaces 134, 136 of graft material 102 for the functions surface 134, 136 participate in. For example, inner coating 306 has pro/rapid-passivation and/or anti-thrombogenic properties while outer coating 304 promotes tissue growth and device fixation. For example, outer coating 304 includes tissue growth promoting material or bioactive molecules.
Further, in one embodiment, armor coating 302 enables further coating product development, such as release of bioactive molecules, e.g., bioactive peptides, RNA silencing, non-coating RNA's and/or drugs.
In one embodiment, armor coating 302 is bioabsorbable, sometimes called a bioabsorbable coating or material. In one specific embodiment, armor coating 302 is poly(glycerol sebacate) (PGS) although other bioabsorbable materials are used in other embodiments. By forming armor coating 302 as being bioabsorbable, armor coating 302 breaks down on a timescale that allows for the biological process of cellular recruitment and proliferation to occur. For example, as armor coating 302 breaks down, armor coating 302 is replaced with fibrocellular tissue, e.g., within six months. The break down profile can be tuned. In accordance with this embodiment, long term durability does not need to be shown and a solution for biological fixation is provided.
By forming armor coating 302 of a bioabsorbable material, the durable elastic properties of armor coating 302 improves the integrity of stent-graft 100 during the harsh deployment, and provides impermeability throughout the problematic time period after deployment. Armor coating 302 prevents leaking through graft material 102 and as armor coating 302 breaks down (biodegrades), clotting will occur. Accordingly, type II endoleaks are not observed soon after stent-graft 100 is deployed thus avoiding intervention and correction by the physician.
In one embodiment, armor coating 302 as a bioabsorbable coating provides a platform to elute a bioactive molecule that can interact in the biological process in a way that effects a more durable outcome. Examples of bioactive molecules include a drug, snRNA, a growth factor, a peptide as well as other bioactive molecules.
However, in other embodiments, armor coating 302 is not bioabsorbable, or has different rates of absorption at different zones of stent-graft 100. By different rates of absorption, armor coating 302 is bioabsorbed faster or slower at different parts of stent-graft 100 such as at the seal zone, e.g., at proximal zone 116 and leg zone 120.
It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a medical device.
In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include non-transitory computer-readable media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer).
Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.

Claims

What is claimed is:

1. A prosthesis comprising:

a graft material having a variable permeability; and

an armor coating on the graft material, the armor coating being impermeable to fluid.

2. The prosthesis of claim 1 wherein the graft material comprises filaments, wherein openings exist between the filaments, the armor coating sealing the openings.

3. The prosthesis of claim 2 wherein the armor coating comprises a filling coating within the openings.

4. The prosthesis of claim 1 wherein the graft material comprises an outer surface, the armor coating comprising an outer coating on the outer surface.

5. The prosthesis of claim 4 wherein the graft material further comprises an inner surface, the armor coating comprising an inner coating on the inner surface.

6. The prosthesis of claim 1 wherein the graft material comprises an inner surface, the armor coating comprising an inner coating on the inner surface.

7. The prosthesis of claim 1 wherein the graft material comprises:

a proximal zone;

a transition zone; and

a leg zone, the transition zone having a greater porosity than the proximal zone and the leg zone, the armor coating being on the transition zone.

8. The prosthesis of claim 1 wherein the graft material comprises polyester terephthalate and the armor coating comprises poly(glycerol sebacate).

9. The prosthesis of claim 1 wherein the armor coating comprises a non-degrading elastomeric material.

10. A prosthesis comprising:

a graft material comprising a suture opening;

stitching extending through the suture opening; and

an armor coating sealing the suture opening.

11. The prosthesis of claim 10 wherein a diameter of the suture opening is greater than a diameter of the stitching.

12. The prosthesis of claim 10 wherein the armor coating is elastic.

13. The prosthesis of claim 12 wherein the armor coating stretches around the stitching.

14. The prosthesis of claim 10 further comprising:

a stent-ring coupled to the graft material by the stitching.

15. The prosthesis of claim 14 wherein the armor coating is between the stent-ring and the graft material.

16. The prosthesis of claim 14 wherein the armor coating covers the stent-ring.

17. The prosthesis of claim 10 further comprising a stitched seam, the stitching holding the stitched seam together.

18. A method comprising:

applying an armor coating to a graft material comprising sealing openings between filaments of the graft material with the armor coating.

19. The method of claim 18 further comprising:

passing stitching through the graft material comprising forming a suture opening in the graft material, wherein the armor coating seals the suture opening.

20. The method of claim 19 wherein the passing stitching through the graft material comprises coupling a stent-ring to the graft material with the stitching.