Patent Description:
In addition, the unique anatomy of each patient typically requires customization during implantation, regardless of the design of the luminal stent, specifically in the degree of expansion of the luminal stent from a collapsed position. More specifically, the stiffness, both radially and longitudinally, may need to vary along the length of a branch stent graft, thereby requiring great precision during implantation. However, branch stent grafts generally available are limited in radial stiffness and longitudinal flexibility, and so must carefully be chosen before, or even during surgery, in order to be properly fit to the fenestration of the implanted prosthesis and accommodate the patient's anatomy. Choosing the wrong luminal stent can be problematic and even tragic in that, once deployed, stents generally cannot be removed and replaced. <CIT> discloses a stent-graft that comprises first and second stents, which each may comprise a series of distal apices disposed distal to a proximal end of the graft, and a series of proximal apices disposed proximally beyond the proximal end of the graft. In one example, the first stent comprises a first uniform segment, and the second stent comprises a second uniform wire segment, where the first uniform segment comprises portions disposed both internal and external to the second uniform wire segment.

Therefore, a need exists for a system and method of aortic treatment that overcomes or minimizes the above mentioned problems.

The invention generally is directed to a luminal stent assembly according to the claims. The disclosure is directed to method of implanting the luminal stent, and to a method of implanting the luminal stent assembly and the luminal stent system. The methods are not according to the invention, which is defined by the claims.

There is described, a luminal stent that includes a plurality of radially-expandable stent components, each radially-expandable stent component having a proximal end and a distal end, wherein at least one of the stent components includes struts that are joined to each other at respective opposite ends, thereby forming proximal apices and distal apices, the radially-expandable stent components being arranged in relative proximal and distal relationship to each other. A plurality of bridges link immediately proximal and distal radially-expandable stent components to each other, thereby forming the luminal stent and defining a continuous lumen, and a proximal end and a distal end of the luminal stent, wherein the axial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of a decrease in the number of bridges spanning, also referred to as "linking," the radially-expandable stent components with increasing distance from the proximal end of the luminal stent, and the radial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of at least one of a increase in the length of the struts of the radially- expandable stent components and a decrease in thickness of the stents of the radially- expandable stent components with increased distance from the proximal end of the luminal stent.

There is also described, a luminal stent assembly that includes a luminal stent and at least one of the luminal graft component and a polymeric coating at the luminal stent. The luminal stent includes a plurality of radially-expandable stent components, each radially- expandable stent component having a proximal end and a distal end, at least one of the stents including struts, wherein the struts include opposite ends and are joined to each other at the respective opposite ends, thereby forming proximal apices and distal apices, the radially expandable stent components being arranged in relative proximal and distal relationship to each other. A plurality of bridges of the luminal stent link immediately proximal and distal radially-expandable stent components to each other, thereby forming the luminal stent and defining a continuous lumen at a proximal and a distal end of the luminal stent, wherein the axial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of a decrease in the number of bridges spanning the radially-expandable stent components with increasing distance from the proximal end of the luminal stent, and the radial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of at least one of a increase in the length of the struts of the radially-expandable stent components and a decrease in thickness of the stents of the radially-expandable stent components with increased distance from the proximal end of the luminal stent. The luminal stent assembly further includes at least one of a luminal graft component and a polymeric coating at the luminal stent, to thereby form the luminal stent assembly.

There is further described, a luminal stent assembly that includes a luminal stent and a balloon within the luminal stent when the luminal stent is in a collapsed position and having a greater diameter at one end and at an opposite end when inflated. The luminal stent includes a plurality of radially-expandable stent components, each radially-expandable stent component having a proximal end and a distal end, at least one of the stent components including struts, the struts including opposite ends that are joined to each other at the respective opposite ends, thereby forming proximal apices and distal apices. The radially-expandable stent components are arranged in relative proximal and distal relationship to each other, and have a plurality of bridges linking immediately proximal and distal radially-expandable stent components to each other, wherein the axial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of a decrease in the number of bridges spanning the radially-expandable stent components with increasing distance from the proximal end of the luminal stent, and the radial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of at least one of a increase in the length of the struts of the radially-expandable stent components and a decrease in thickness of the stents of the radially-expandable stent components with increased distance from the proximal end of the luminal stent. A balloon is within the luminal stent when the luminal stent is in a collapsed state and has a greater diameter at one end than an opposite end when inflated.

There is further described, a luminal stent assembly that includes a luminal stent, at least one of a luminal graft component and a polymeric coating at the luminal stent, to thereby form the luminal stent assembly, the luminal stent assembly having a proximal end and a distal end, and a balloon within the luminal stent when the luminal stent is in a collapsed position and having a greater diameter at one end and at an opposite end when inflated. The luminal stent includes a plurality of radially-expandable stent components, each radially-expandable stent component having a proximal end and a distal end, at least one of the stent components including struts, the struts including opposite ends that are joined to each other at the respective opposite ends, thereby forming proximal apices and distal apices. The radially-expandable stent components are arranged in relative proximal and distal relationship to each other, and have a plurality of bridges linking immediately proximal and distal radially-expandable stent components to each other, wherein the axial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of a decrease in the number of bridges spanning the radially-expandable stent components with increasing distance from the proximal end of the luminal stent, and the radial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of at least one of a increase in the length of the struts of the radially-expandable stent components and a decrease in thickness of the stents of the radially-expandable stent components with increased distance from the proximal end of the luminal stent. A balloon is within the luminal stent when the luminal stent is in a collapsed state and has a greater diameter at one end than an opposite end when inflated.

There is further described, a stent graft system that includes a luminal stent assembly that includes a luminal stent having a plurality of radially-expandable stent components radially-expandable stent component having approximately an end and a distal end, at least one of the stent components including struts, where the struts include opposite ends and are joined to each other at the respective opposite ends, thereby forming proximal apices and distal apices, the radially-expandable stent components being arranged in relative proximal and distal relationship to each other, and a plurality of bridges link immediately proximal and distal radially-expandable stent components to each other, wherein the axial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of a decrease in the number of bridges spanning the radially-expandable stent components with increasing distance from the proximal end of the luminal stent, and the radial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of at least one of a increase in the length of the struts of the radially-expandable stent components and a decrease in thickness of the stents of the radially-expandable stent components with increased distance from the proximal end of the luminal stent. A plurality of bridges linking immediately proximal and distal radially-expandable stent components to each other. At least one of the luminal graft component and the polymeric coating is at the luminal stent. A balloon is within the luminal stent when a luminal stent is in a collapsed position and has a greater diameter at one end and an opposite end when inflated.

There is further described, a luminal stent assembly that includes a luminal stent and at least one of a luminal graft component and a polymeric coating. The luminal stent includes a plurality of radially-expandable stent components, each radially-expandable stent component having a proximal end and a distal end, at least one of the stent components including struts, wherein the struts include opposite ends and are joined to each other at the respective opposite ends, thereby forming proximal apices and distal apices, the radially-expandable stent components being nested in relative proximal and distal relationship to each other. A plurality of bridges link immediately proximal and distal radially-expandable stent components to each other at at least one of the respective proximal apices and respective distal apices, thereby forming the luminal stent and defining a continuous lumen, a proximal end, and a distal end of the luminal stent. At least one of a luminal graft component and a polymeric coating is at the luminal stent to thereby form the luminal stent assembly, wherein the luminal stent assembly has a proximal end and a distal end.

There is further described, a luminal stent assembly that includes at least one luminal stent, at least one of a luminal graft component and a polymeric coating, and at least one stent distal to the luminal stent. The luminal stent includes a plurality of radially-expandable stent components, each radially-expandable stent component having a proximal end and a distal end, at least one of the stent components including struts, wherein the struts include opposite ends and are joined to each other at the respective opposite ends, thereby forming proximal apices and distal apices, the radially-expandable stent components being in relative proximal and distal relationship to each other. A plurality of bridges link, immediately proximal and distal radially-expandable stent components to each other, thereby forming the luminal stent and defining a continuous lumen, a proximal end, and a distal end of the luminal stent. At least one of the luminal graft component and the polymeric coating are at the luminal stent. At least one stent is distal to the luminal stent and is linked to the luminal stent by at least one of the luminal graft component and the polymeric coating to thereby form the luminal stent assembly, the luminal stent assembly having a proximal end at the luminal stent and a distal end at the stent distal to the luminal stent. The axial stiffness of the luminal stent assembly decreases from the proximal end to the distal end of the luminal stent assembly as a consequence of a space between the luminal stent and the at least one stent distal to the luminal stent, and the radial stiffness of the luminal stent is greater than the radial stiffness of the at least one distal stent.

There is also described, a plurality of radially-expandable stent components. Each radially-expandable stent component has a proximal end and a distal end, at least one of the stent components including struts, wherein the struts include opposite ends and are joined to each other at the respective opposite ends, thereby forming proximal apices and distal apices, the radially-expandable stent components being in relative proximal and distal relationship to each other. The radial stiffness of each radially expandable stent component is less than that of each radially expandable stent component proximal to it and greater than that of each radially-expandable stent component distal to it. At least one of a luminal graft component and a polymeric coating link the plurality of radially-expandable stent components.

There is also described, a stent graft assembly that includes a luminal stent assembly that includes a luminal stent having a plurality of radially-expandable stent components, at least one of the stent components including struts, where the struts include opposite ends and are joined to each other at the respective opposite ends, thereby forming proximal apices and distal apices, the radially-expandable stent components being arranged in relative proximal and distal relationship to each other, and a plurality of bridges link immediately proximal and distal radially-expandable stent components to each other, wherein the axial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of a decrease in the number of bridges spanning the radially-expandable stent components with increasing distance from the proximal end of the luminal stent, and the radial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of at least one of a increase in the length of the struts of the radially-expandable stent components and a decrease in thickness of the stents of the radially-expandable stent components with increased distance from the proximal end of the luminal stent. A plurality of bridges linking immediately proximal and distal radially-expandable stent components to each other. At least one of the luminal graft component and the polymeric coating is at the luminal stent. A balloon is within the luminal stent when a luminal stent is in a collapsed position. A fenestrated stent graft of the luminal stent system defines at least one fenestration, wherein the luminal stent has a diameter less than the fenestration when in a collapsed position, and is expandable to a diameter that fixes the proximal end of the luminal stent within the fenestration, whereby the distal end of the luminal stent extends radially from stent graft.

There is also described, a method of implanting a stent graft system that includes delivering a fenestrated stent graft of the stent graft system to a branched artery of a subject, wherein a fenestration defined by the fenestrated stent graft lies with a proximal end of the branch artery. A luminal stent of the luminal stent system has a plurality of radially-expandable stent components, at least one of the stent components including struts, where the struts include opposite ends and are joined to each other at the respective opposite ends, thereby forming proximal apices and distal apices, the radially-expandable stent components being arranged in relative proximal and distal relationship to each other, and a plurality of bridges link immediately proximal and distal radially-expandable stent components to each other, wherein the axial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of a decrease in the number of bridges spanning the radially-expandable stent components with increasing distance from the proximal end of the luminal stent, and the radial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of at least one of a increase in the length of the struts of the radially-expandable stent components and a decrease in thickness of the stents of the radially-expandable stent components with increased distance from the proximal end of the luminal stent. The luminal stent of the stent graft system is delivered at least partially through the fenestration and into the arterial branch, the luminal stent having a proximal end at the fenestration of the fenestrated stent graft and a distal end extending radially outward from the fenestrated stent graft. A luminal stent is radially expanded within the fenestration and the arterial branch by inflating a balloon within the luminal stent that has a greater diameter at the proximal end of the luminal stent and at the distal end of the luminal stent, thereby implanting the stent graft system.

There is also described, a method of implanting a stent graft system that includes delivering a fenestrated stent graft of the stent graft system to a branch artery of a subject, wherein the fenestration defined by the fenestrated stent graft aligns with the proximal end of the branch artery. A luminal stent assembly of a stent graft system is delivered at least partially through the fenestration and into the arterial branch, the luminal stent assembly thereby bridging the fenestrated stent graft and the arterial branch. The luminal stent assembly includes a plurality of stents aligned longitudinally and connected by bridges to form a luminal stent, wherein the axial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of a decrease in the number of bridges spanning the radially-expandable stent components with increasing distance from the proximal end of the luminal stent, and the radial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of at least one of a increase in the length of the struts of the radially-expandable stent components and a decrease in thickness of the stents of the radially-expandable stent components with increased distance from the proximal end of the luminal stent. At least one stent distal to the luminal stent has a radial stiffness less than that of the luminal stent, and at least one of a luminal graft component and a polymeric coating linking the luminal stent and the stent distal to the luminal stent. The luminal stent assembly is radially expanded within the fenestration and the arterial branch by inflating the balloon within the luminal stent assembly, wherein the balloon has a diameter at the luminal stent greater than at the stent distal to the luminal stent when inflated, thereby implanting the stent graft system.

This invention has several advantages. For example, by varying the radial and axial stiffness of a luminal, or bridging, stent, the physician can place a proximal portion of the luminal stent that is radially stiff, relative to a distal end of the luminal stent, within a fenestrated opening of a fenestrated stent graft prosthesis, thereby allowing for a better seal at the stent graft prosthesis, and reducing potential for the luminal stent to dislodge from the fenestration by, at least on one embodiment, forming an hour-glass configuration on either side of the fenestration. Simultaneously, the distal portion of the luminal stents, where radial stiffness is low relative to the proximal portion of the luminal stent, can be placed inside of a targeted vessel, thereby maintaining appropriate radial support, consequently reducing the potential of the vessel to be occluded by thrombus formation, while allowing for axial flexibility within the vessel.

Optional inclusion of a balloon having a greater diameter at the proximal end of the luminal stent during implantation minimizes or eliminates the need to remove a first balloon and substitute it with a second balloon to preferentially flare a proximal end of the luminal stent. This reduces the time requirement of the overall procedure and reduces trauma to the patient. Marker band locations and configurations can be employed to show the proximal and distal ends of the stent along with location of a transitional area of the balloon having greater and lesser expanded diameters, thereby aiding the physician and placement of the luminal stent in the fenestration, and ensuring that a flared area of the stent is properly engaged with the fenestration opening in the fenestrated stent graft. Also optionally, the distal portion of the luminal stent of the invention can be left uncovered, thereby enabling the luminal stent to be employed in bifurcated vessels without obstructing blood flow to either the branch vessel or the bifurcation, as opposed to current procedures where the physician employs a covered stent and then deploys an uncovered self-expanding stent into the area of the bifurcation.

The features and other details of the invention, either as steps of the invention or as combinations of parts of the invention, will now be more particularly described and pointed out in the claims. It will be understood that the particular embodiments of the invention are shown by way of illustration and not as limitations of the invention. The principal features of this invention can be employed in various embodiments without departing from the scope of the invention.

The present invention generally is directed to a luminal stent assembly as shown in the claims. The invention is useful in methods of implanting the luminal stent, the stent graft assembly and the luminal stent system in a branched artery to treat diseased tissue at the branched artery. The luminal stent includes a plurality of radially-expandable stent components and a plurality of bridges linking immediately proximal and distal radially-expandable stent components to each other. In one embodiment, the axial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of a decrease in the number of bridges spanning, also referred to as "linking," the radially-expandable stent components with increasing distance from the proximal end of the luminal stent, and the radial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent as a consequence of at least one of a increase in the length of the struts of the radially-expandable stent components and a decrease in thickness of the stents of the radially-expandable stent components with increased distance from the proximal end of the luminal stent.

The luminal stent assembly, includes the luminal stent assembly of the invention and at least one of a luminal graft component and a polymeric coating at the luminal stent. The luminal stent system includes a luminal stent assembly from the invention, at least one of the luminal graft component and a polymeric coating at the luminal stent, a balloon within the luminal stent when the luminal stent is in a collapsed position that has a greater diameter at one end than an opposite end when inflated, and a fenestrated stent graft defining at least one fenestration, wherein the luminal stent has a diameter of less than the fenestration when in a collapsed position, and is expandable to a diameter that fixes the proximal end of the luminal stent within the fenestration, whereby the distal end of the luminal stent extends radially from the stent graft.

One version of the method using the invention includes delivering the fenestrated stent graft of the luminal stent system to a branched artery, delivering a luminal stent of the stent graph system at least partially through a fenestration of the fenestrated stent graft, and radially expanding the proximal end of the luminal stent within the fenestration, and expanding the distal end of the luminal stent within an arterial branch of a patient by inflating a balloon within the luminal stent. In another version the method includes delivering a luminal stent assembly that includes a plurality of stents aligned longitudinally and connected by bridges to form a luminal stent, the stent distal to the luminal stent having a radial stiffness less than that of the radial stent, and at least one of the luminal graft component and a polymeric coating linking the luminal stent and the stent distal to the luminal stent. The luminal stent is radially-expanded within the fenestration of a fenestrated graft and within an arterial branch of the patient by inflating the balloon within the luminal stent assembly and when the balloon has a greater diameter at the luminal stent than at the distal to the luminal stent when inflated, thereby implanting the stent graph system.

<FIG> is representative of a luminal stent. Luminal stent <NUM> includes proximal end <NUM> and distal end <NUM> and is made up of radially-expandable stent components <NUM>. Struts <NUM> of each radially-expandable stent component <NUM> include proximal end <NUM> and distal end <NUM> opposite to each other. Respective proximal ends <NUM> of struts <NUM> are joined, as are distal ends <NUM> of struts <NUM>, thereby forming proximal apices <NUM> and distal apices <NUM>, as shown in <FIG>. Radially-expandable stent components <NUM> are arranged in relative proximal and distal relationship to each other, extending from proximal end <NUM> of luminal stent <NUM> to distal end <NUM> of luminal stent <NUM>.

Referring back to <FIG>, radially-expandable stent components <NUM> are linked by bridges <NUM> between immediately proximal and distal radially-expandable stent components <NUM> to each other to thereby form luminal stent <NUM> and define continuous lumen <NUM> extending from proximal end <NUM> to distal end <NUM> of luminal stent <NUM>, as shown in FIG. IB, which is across-section taken along line IB-IB of <FIG>.

In the embodiment shown in <FIG>, at least a portion of bridges <NUM> link at least a portion of distal apices <NUM> and proximal apices <NUM> of respective proximal and distal radially-expandable stent components <NUM>. It is to be understood, however, that in other versions, not shown, bridges <NUM> can link immediately distal and proximal radially-expandable stent components <NUM> at struts <NUM> of respective radially-expandable stent components <NUM> or between distal apex <NUM> or proximal apex <NUM> of a radially-expandable stent component <NUM> and a strut <NUM> of the respective immediately-distal or immediately proximal radially-expandable stent component <NUM>. In another version, also not shown, apices of one radially-expandable stent component can be nested between proximal and distal apices of respective distal and proximal radially-expandable stent components, and can be joined by bridges between struts of immediately proximal and distal radially-expandable stent components, or between apices and struts of those components.

In an version, such as that shown in <FIG>, at least a portion of bridges <NUM> have a longitudinal axis <NUM> transverse to longitudinal axis <NUM>. Longitudinal axis <NUM> is parallel to longitudinal axis <NUM> of luminal stent <NUM> of continuous lumen <NUM> defined by radially-expandable stent components <NUM> of luminal stent <NUM>. As a consequence of this orientation of bridges <NUM>, luminal stent <NUM> is axially flexible.

As can be seen in FIG. ID, axis <NUM> normal to a proximal end <NUM> of luminal stent <NUM> can have variable angle A', A" with axes <NUM>', <NUM>", respectively, normal to distal end <NUM> of luminal stent <NUM> by flexation of luminal stent <NUM>, as shown in FIG. This flexation is referenced herein as "axial flexibility," or "bending flexibility. " "Axial stiffness," or "bending stiffness," as defined herein, means resistance to axial flexation.

Luminal stent <NUM>, as shown in the embodiment of <FIG>, is in a radially-expanded position and has diameter D'. In <FIG>, luminal stent <NUM> is shown in a collapsed position, where diameter D" of luminal stent <NUM> is less than that of diameter D' of luminal stent <NUM> when in a radially collapsed position, as shown in <FIG>. In one version, radially-expandable stent components <NUM> exhibit resistance to radial expansion from the radially collapsed position, shown in <FIG>, to the radially- expanded position, shown in <FIG>. In this version, radial expansion of radially-expandable stent components <NUM> is effected by balloon <NUM> disposed within luminal stent <NUM> when the luminal stent <NUM> is in a collapsed position, as shown in <FIG>. Balloon <NUM> includes proximal end <NUM> located at proximal end <NUM> of luminal stent <NUM> and distal end <NUM> located at distal end <NUM> of luminal stent <NUM>. Balloon catheter <NUM> extends from distal end <NUM> of balloon <NUM> and is employed to inflate balloon <NUM> by directing fluid from a suitable source <NUM> to balloon during implantation of luminal stent <NUM>. Inflation of balloon <NUM> by direction of fluid from fluid source <NUM> through balloon catheter <NUM> causes radial expansion of luminal stent <NUM> to an expanded position, as shown in <FIG>. Radially-expandable stent components <NUM> are fabricated of a suitable material, such as at least one member selected from the group consisting of stainless steel, cobalt (Co), Nitinol (Ni-Ti), cobalt-chromium alloy (<NUM>), and titanium (Ti).

In another version, radial stiffness of radially-expandable stent components <NUM> includes resistance to radial collapse from a radially expanded position. In this version, at least a portion of radially-expandable stent components <NUM> of luminal stent <NUM> include at least one member selected from the group consisting of stainless steel, cobalt (Co), Nitinol (Ni-Ti), cobalt-chromium alloy (<NUM>), and titanium (Ti). In still another version, radially-expandable stent components <NUM> include a shape-memory elastic metal, such as Nitinol. In a specific version the shape-memory elastic metal of the radially-expandable stent components <NUM> includes Nitinol. In another specific version the shape-memory elastic metal of the radially-expandable stent components <NUM> is Nitinol. In still another version, a portion of radially-expandable stent components <NUM> of luminal stent <NUM> include, or are formed of a shape-memory elastic metal, such as Nitinol, and are self-expanding, and another portion of radially-expandable stent components <NUM> are balloon-expandable, and are formed of, for example, at least one member selected from the group consisting of stainless steel, cobalt (Co), Nitinol (Ni-Ti), cobalt-chromium alloy (<NUM>), and titanium (Ti).

"Radial-expandability," as defined herein, means an ability to increase in a dimension normal to a longitudinal axis of an elongate object, such as luminal stent, <NUM> when inflated from a collapsed position, shown in <FIG>, to an inflated position, shown in <FIG>. Self expanding stents would not need a balloon to expand unless they were secured to the balloon.

"Radial-contractability," as defined herein, means the opposite of radial expandability.

"Radial stiffness," as defined herein, means resistance to at least one of radial-expansion and radial-contraction of a diameter of a radially-expandable stent component.

A luminal stent <NUM> has an axial stiffness that decreases from proximal end <NUM> to distal end <NUM> of luminal stent <NUM>. The mechanism of reduced axial stiffness along a longitudinal length of luminal stent <NUM> from proximal end <NUM> to distal end <NUM> can be a consequence of any suitable mechanism known in the art. In one embodiment, shown in <FIG>, decreasing axial stiffness from proximal end <NUM> to distal end <NUM> of luminal stent <NUM> is a consequence of a diminishment of the number of bridges <NUM> spanning radially-expandable stent components <NUM> with increased distance from proximal end of luminal stent <NUM>.

In another version, radial stiffness of luminal stent <NUM> decreases with increasing distance from proximal end <NUM> of luminal stent <NUM> as a consequence of any suitable mechanism known in the art. For example, as shown in <FIG>, wherein luminal stent <NUM> is shown in an expanded position, an increase in length L of struts of radially-expandable stent components <NUM> with increased distance from proximal end <NUM> of luminal stent <NUM> toward distal end <NUM> causes a decrease in radial stiffness with increasing distance from proximal end <NUM>. Specifically, L' is greater than L", and can be progressively so with increasing distance from proximal end <NUM> toward distal end <NUM> of luminal stent <NUM>. <FIG> is a side view of luminal stent <NUM> in a collapsed position.

In yet another version, not shown, decreasing radial stiffness with increasing distance from a proximal end of a stent component is a consequence of a decrease in thickness of at least a portion of struts of radially expandable stent components with increased distance from proximal end of luminal stent. For example, <FIG> is a radially expandable stent <NUM>. <FIG> is a cross section of radially-expandable stent <NUM>, shown in <FIG>, taken along line 7A-7A. <FIG> is a detail of a cross section of one strut <NUM> of radially-expandable stent <NUM>. "Thickness" of struts, as referenced herein, whether reference is made to a radially-expandable stent component of a luminal stent or of a radially-expandable stent, means the width W of the strut in a plane tangential to a lumen defined by the luminal stent, as shown in <FIG>, as opposed to a depth D, also shown in <FIG>.

In other versions, not shown, decreasing radial stiffness with increasing distance from a proximal end of a luminal stent is a consequence of both an increase in the length of the struts of the radially-expandable stent components and a decrease in thickness of the struts of the radially expandable stent components with distance from the proximal end of the luminal stent. In still another version, also not shown, a luminal stent exhibits both a decrease in axial stiffness as a consequence of a decrease in the number of bridges spanning the radially-expandable stent components with increasing distance from a proximal end of a luminal stent, and a decrease in radial stiffness with increased distance from proximal end of the luminal stent as a consequence of at least one of an increase in the length of the struts of the radially-expandable stent components and a decrease in thickness of the struts of the radially-expandable stent components with increasing distance from the proximal end of the luminal stent. In another version, luminal stent exhibits both a decrease in axial stiffness as a consequence of a decrease in the number of bridges spanning the radially-expandable stent components with increasing distance from proximal end of luminal stent, and a decrease in radial stiffness with increased distance from proximal end of the luminal stent as a consequence of both an increase in the length of struts of radially-expandable stent components and a decrease in thickness of the struts of radially-expandable stent components with increasing distance from proximal end of luminal stent.

Diminishment of either or both of axial stiffness and radial stiffness can be progressive or stepped. Whether progressive or stepped, diminishment of either axial or radial stiffness, in specific embodiments, will not be interrupted by increases of that axial or radial stiffness along that progression. For example, a progression of diminished radial stiffness can be continuous or stepped along a series of radially-expanding stents, despite the fact that they are linked by a luminal graft or a polymeric coating that does not have a radial stiffness that also progressively diminishes.

In one version, at least one of the axial stiffness and the radial stiffness of the luminal stent is stepped. For example, in one version, luminal stent <NUM> includes incremental juncture <NUM>, at which the number of bridges <NUM> between radially-expanding stent components <NUM> changes, as shown in <FIG>, whereby the axial stiffness of luminal stent <NUM> changes in an increment between proximal end <NUM> and distal end <NUM> of luminal stent <NUM> as a consequence of a reduction in the number of bridges <NUM> between radially-expandable stent components <NUM> with increasing distance from proximal end <NUM> of luminal stent <NUM>. In another version, radial stiffness of luminal stent <NUM> decreases in steps by either or both an increase in the length of struts <NUM> of immediately proximal radially-expandable stent components <NUM> and immediately distal radially-expandable stent components <NUM>, as shown in <FIG>, and a decrease in thickness (or "width W," as described above with respect to <FIG>) of struts of immediately proximal and distal radially-expandable stent components, either of which can be employed to establish juncture <NUM> between radial stiffness proximal to juncture <NUM> and radial stiffness distal to juncture <NUM>. A luminal stent can include a plurality of incremental junctures in axial stiffness, radial stiffness, or both, wherein axial or radial stiffness of the luminal stent is constant proximal to the most proximal juncture, between junctures, and distal to the most distal juncture. Radial markers <NUM> can be fixed at luminal stent <NUM>, such as at junctures <NUM> of luminal stent <NUM>, as is also shown in <FIG>.

Another version is directed to a luminal stent assembly that includes a luminal stent, such as described above, having a plurality of radially-expandable stent components, each radially-expandable stent component having a proximal end and distal end, at least one of the stent components including struts, wherein the struts include opposite ends and are joined to each other at the respective opposite ends, thereby forming proximal apices and distal apices, the radially-expandable stent components being arranged in relative proximal and distal relationship to each other, and a plurality of bridges linking immediately proximal and distal radially-expandable stent components to each other, thereby forming luminal stent and defining a continuous lumen, and a proximal end and a distal end of luminal stent, wherein at least one of axial stiffness and radial stiffness of the luminal stent decreases from proximal end to distal end of luminal stent. In this version, the luminal stent assembly further includes at least one of a luminal graft component and a polymer coating at the luminal stent.

For example, as shown in <FIG>, luminal stent assembly <NUM> includes luminal graft component <NUM> at luminal stent <NUM>. Luminal stent assembly includes proximal end <NUM> and distal end <NUM>. Luminal stent <NUM> includes proximal end 87a and distal end 87b. As can be seen in <FIG>, the number of bridges between radially-expandable stent components of luminal stent <NUM> decreases with increasing distance from proximal end 87a to distal end 87b of luminal stent <NUM>. <FIG> is a cross-section of <FIG> taken along line 10A-10A. As shown therein, luminal graft component, in this embodiment, is within lumen <NUM> defined as luminal stent <NUM>. Although not necessarily so in other versions, luminal graft component <NUM> extends distally from distal end 87b of luminal stent <NUM>.

In another versions, shown in <FIG>, luminal stent assembly <NUM> includes luminal stent <NUM> having proximal end <NUM> and distal end <NUM>, wherein a portion of luminal stent <NUM> is bare at distal end <NUM>. In another version, not shown, the luminal stent is completely covered on the outside by a luminal graft component.

In another version, shown in <FIG>, luminal stent assembly <NUM> has proximal end 95a and distal end 95b, and includes luminal graft component <NUM> extending distally from distal end <NUM> of luminal stent <NUM>, and further includes at least one radially-expandable stent <NUM> at luminal graft component <NUM> and distal to luminal stent <NUM>. In one specific version, the axial stiffness of luminal stent <NUM> decreases with increasing distance from proximal end <NUM> to distal end <NUM> of luminal stent <NUM> with increasing distance from luminal stent <NUM> as a result of a decreasing number of bridges from, for example, eight to four to two with increasing distance from proximal end 95a to distal end 95b. The axial stiffness can also decrease as a consequence of increasing distance D between luminal stent <NUM> and distal stent <NUM>, and between distal stents <NUM>. In one specific embodiment, the radial stiffness of luminal stent <NUM> decreases from proximal end <NUM> to distal end <NUM> of luminal stent <NUM>. In one such version, the radial stiffness of luminal stent assembly <NUM> decreases with increasing distance from proximal end <NUM> of luminal stent to distal end <NUM> of luminal stent <NUM>. In another version, the radial stiffness of luminal stent <NUM> is constant from proximal end <NUM> to distal end <NUM> of luminal stent <NUM>. In this embodiment, the radial stiffness of radially-expandable stent <NUM> distal to luminal stent <NUM> is less than that of at least a portion of radially-expandable stent components <NUM> of luminal stent <NUM>. In one specific version the radial stiffness of radially-expandable stent <NUM> distal to luminal stent <NUM> is less than that of most distal radially-expandable stent component <NUM> of luminal stent <NUM>. In another version, the radial stiffness of the radially-expandable stent <NUM> is less than that of the luminal stent <NUM> at proximal end <NUM> of luminal stent <NUM>.

It is to be understood that the radial stiffness of radially-expandable stent <NUM> can include resistance to radial expansion from a radially-collapsed position, or resistance to radial collapse from a radially-expanded position, or both. In addition, at least one of the radially-expandable stents <NUM> distal to luminal stent <NUM>, shown in <FIG>, can include the same material or composition as that of luminal stent <NUM>, or may be of a different material or composition than that of luminal stent <NUM>.

In another version, shown in <FIG>, luminal stent assembly <NUM> has proximal end <NUM> and distal end <NUM>, and includes luminal stent <NUM> having proximal end <NUM> and distal end <NUM>. Luminal graft component <NUM> extends distally from distal end <NUM> of luminal stent <NUM>. Struts <NUM> of luminal stent <NUM> become progressively longer from proximal end <NUM> to distal end <NUM> of luminal stent <NUM>. Radially-expandable stent <NUM> is distal to distal end <NUM> of luminal stent <NUM> and includes two radially-expandable stent subcomponents <NUM>, <NUM>. Each stent subcomponent <NUM>, <NUM> includes struts <NUM> that define proximal apices <NUM> and distal apices <NUM> and are joined by bridge <NUM>. It is to be understood that, in alternative versions, more than one radially-expandable stent can be employed. It is also to be understood that, in versions where at least one radially expandable stent <NUM> distal to distal end <NUM> of luminal stent <NUM> includes radially-expandable stent components <NUM>, <NUM>, that more than two radially-expandable stent subcomponents can be employed in each radially-expandable stent. In one specific version shown in <FIG>, bridge <NUM> extends from a distal apex <NUM> of a most-proximal radially-expandable stent subcomponent <NUM> to a proximal apex <NUM> of a most distal radially-expandable stent subcomponent <NUM> of radially-expandable stent <NUM>.

It is to be understood further that struts of the radially-expandable stent distal to the luminal stent can have a length different than those of the radially-expandable stent components of the luminal stent. For example, as shown in <FIG>, luminal stent assembly <NUM> having proximal end 131a and 131b, includes struts <NUM> of radially-expandable stent <NUM> distal to luminal stent <NUM> that can be longer than struts <NUM> of radially-expandable stent components <NUM> of luminal stent <NUM>, thereby causing the radial stiffness of radially-expandable stent <NUM> distal to luminal stent <NUM> to be less than that of radially-expandable stent components <NUM> of luminal stent <NUM>.

In yet another version, shown in <FIG>, luminal stent assembly <NUM> includes luminal stent <NUM> having proximal end <NUM> and distal end <NUM>. Luminal stent assembly <NUM> further includes polymer coating <NUM>. As can be seen in <FIG>, which is a cross section of luminal stent assembly <NUM> taken along line 15A-15A of <FIG>, polymeric coating <NUM> coats outside surface <NUM> of luminal stent <NUM> and inside surface <NUM> of luminal stent <NUM>. In other versions, polymeric coating <NUM> may coat only one of outside surface <NUM> and inside surface <NUM> of luminal stent <NUM>.

Polymer coating <NUM> includes at least one layer of polymer. In one version, polymeric coating includes at least one member of the group consisting of polytetrafluoroethylene (PTFE), such as expanded PTFE (ePTFE), polyethylene terephthalate, eSPUN PTFE, FEP, PU (polyurethane), silicone, ePTFE with PU bond catalyst, and ePTFE with FEP bond catalyst. In a specific embodiment, polymeric coating <NUM> includes ePTFE. In a still more specific embodiment, polymeric coating <NUM> is ePTFE.

In another version, polymeric coating <NUM> coats inside surface <NUM> of luminal stent <NUM> and outside surface <NUM> of luminal stent <NUM>, and includes a plurality of layers on at least one of inside surface <NUM> of luminal stent <NUM> and outside surface <NUM> of luminal stent <NUM>. In a specific version, polymeric coating <NUM> includes a plurality of polymer layers on both inside surface <NUM> and outside surface of luminal stent <NUM>. In yet another embodiment, there are more layers of polymeric coating at at least one of distal end <NUM> and proximal end <NUM> of the luminal stent <NUM> than between distal end <NUM> and proximal end <NUM> of luminal stent <NUM>. In yet another version, there are more layers of polymer of polymeric coating <NUM> at both distal end <NUM> and proximal end <NUM> of luminal stent <NUM> than between distal end <NUM> and proximal end <NUM> of luminal stent <NUM>.

In yet another version, polymeric coating <NUM> on inside surface <NUM> and outside surface <NUM> of luminal stent <NUM> is continuous. In one such version, luminal stent <NUM> defines openings <NUM> and polymeric coating <NUM> seals openings. In still another version, the total thickness of polymeric coating <NUM> on inside surface <NUM> of luminal stent is greater than the total thickness of polymeric coating <NUM> on outside surface <NUM> of luminal stent <NUM>. In one such version, the total thickness of polymeric coating <NUM> on inside surface <NUM> of luminal stent <NUM> is in a range of between about <NUM> and about <NUM>. In another such version, the total thickness of polymer coating <NUM> on outside surface <NUM> of luminal stent <NUM> is in a range of between about <NUM> and about <NUM>. In a specific version, the total thickness of polymer coating <NUM> on inside surface <NUM> of luminal stent <NUM> can range from <NUM> to <NUM>, and the total thickness of polymer coating <NUM> on outside surface <NUM> of luminal stent <NUM> can range from <NUM> to <NUM>.

In still another version, not shown, polymeric coating <NUM> covers inside surface <NUM> of luminal stent <NUM>, outside surface <NUM>. In one specific version, shown in <FIG>, both outside surface <NUM> and inside surface <NUM> of luminal stent. Optionally, and not shown, a graft component can be present and cover polymer coating <NUM> on outside surface <NUM> of luminal stent <NUM>. In at least one version, proximal end <NUM> and distal end <NUM> of polymeric coating <NUM> are fabricated to prevent preferential radial expansion between proximal end <NUM> and distal end <NUM> of luminal stent <NUM>. Such radial expansion, also known as "dog-boning," can be largely or completely avoided, at least in one version, by forming polymeric coating <NUM> with more polymeric layers at proximal end <NUM> and at distal end <NUM> of polymeric coating <NUM> than between proximal end <NUM> and distal end <NUM> of polymeric coating <NUM>. A benefit of this particular version is that, during implantation, the likelihood of damage to the peripheral branch artery in which luminal stent assembly <NUM> is being implanted is diminished during radial expansion.

In one version, as shown in <FIG>, luminal stent assembly <NUM> includes polymeric coating <NUM> that extends distally from distal end <NUM> of luminal stent <NUM>. Radially-expandable stent <NUM> is distal to luminal stent <NUM> and is also at polymeric coating <NUM>. In this version, the radial stiffness of radially-expandable stent <NUM> is less than that of at least a portion of luminal stent <NUM>. As previously explained, the radial stiffness of radially expandable stent <NUM> can include resistance to radial expansion from a radially-collapsed position, resistance to radial collapse from a radially-expanded position, or both. Further, and as also previously described, at least one of radially-expandable stents <NUM> distal to distal end <NUM> of luminal stent <NUM> can be formed of the same material composition as that of luminal stent <NUM>. Although not shown, the most proximal of radially-expandable stent components <NUM> at proximal end <NUM> of luminal stent <NUM> can be flared. In another version, and as also explained above, at least one of radially-expandable stents <NUM> distal to distal end <NUM> of luminal stent <NUM> can include two radially-expandable stent subcomponents <NUM>, <NUM>, each radially-expandable stent component <NUM>, <NUM> including struts <NUM> that define proximal and distal apices <NUM>, <NUM>, wherein radially-expandable stent subcomponents <NUM>, <NUM> are joined by at least one bridge <NUM>. In such a version, at least one bridge <NUM> of radially-expandable stent <NUM> can extend from distal apex <NUM> of most-proximal radially-expandable stent subcomponent <NUM> to proximal apex <NUM> of most-distal radially-expandable stent subcomponent <NUM> of radially-expandable stent <NUM>. In this embodiment, axial stiffness of luminal stent assembly <NUM> is decreased at distal end <NUM> of luminal stent assembly <NUM> relative to proximal end <NUM> of luminal stent assembly <NUM> because there are fewer bridges <NUM> linking radially-expandable stent subcomponents <NUM>, <NUM> of radially-expandable stent <NUM> than there are bridges <NUM> linking radially-expandable stent subcomponents <NUM> of luminal stent <NUM>. Axial stiffness of luminal stent assembly <NUM> is also lower at distal end <NUM> than at proximal end <NUM> of luminal stent assembly because luminal stent <NUM> has a greater longitudinal length L than the length L' of any radially expandable stents <NUM> distal to distal end <NUM> of luminal stent <NUM>.

In another version, struts of radially-expandable stents can have a length different than those of at least a portion of radially-expandable stent components of luminal stent. For example, as shown in <FIG>, luminal stent assembly <NUM> has proximal end 191a and 191b, and includes radially-expandable stents <NUM> distal to luminal stent <NUM>, wherein struts <NUM> of luminal stent <NUM> are longer than at least a portion of struts <NUM> of radially-expandable stent components <NUM> of luminal stent <NUM>. In one version, at least one of axial and radial stiffness of luminal stent <NUM> is stepped, wherein luminal stent <NUM> further includes an incremental juncture, as described with respect to earlier versions described above, whereby at least one of axial stiffness and radial stiffness of luminal stent <NUM> changes in at least one incremental juncture. In a more specific version, luminal stent <NUM> includes a plurality of incremental junctures, whereby radial stiffness of radially-expandable stent components <NUM> of luminal stent <NUM> decreases with increasing distance from proximal end <NUM> of luminal stent <NUM>. In yet another version, and as further described above with respect to earlier versions, luminal stent assembly <NUM> can include at least one radiopaque marker <NUM> at luminal stent <NUM>, such as at at least one of a plurality of incremental junctures <NUM> of luminal stent <NUM>.

At least one radially-expandable stent <NUM> distal to distal end <NUM> of luminal stent <NUM> includes two radially-expandable stent subcomponents <NUM>, <NUM>, each radially-expandable stent subcomponent <NUM>, <NUM> including struts <NUM> that are joined to define distal apices <NUM> and proximal apices <NUM>, and wherein radially-expandable stent subcomponents <NUM>, <NUM> are joined by at least one bridge <NUM>. In at least one version, bridges <NUM> extend transversely to longitudinal axis <NUM> of luminal stent assembly <NUM>. In another version, not shown and as previously described, struts of radially-expandable stent subcomponents have at least one of a length greater, or a thickness less than those of radially-expandable stent components <NUM> of the luminal stent <NUM>.

In still another version, luminal stent assembly includes balloon <NUM>, shown alone and inflated in <FIG>. Balloon <NUM> is linked to a fluid source, not shown, by catheter <NUM>. Balloon <NUM> has a greater diameter D at proximal end <NUM> than diameter D' at distal end <NUM> when inflated. As shown in <FIG>, balloon <NUM> is located within luminal stent <NUM>. Luminal stent assembly <NUM> has proximal end <NUM> and distal end <NUM>, and is made up, at least in part, of luminal stent <NUM> and a plurality of radically-expandable stents <NUM> distal to luminal stent. Luminal stent <NUM> includes proximal end <NUM> and distal end <NUM>, and radially-expandable stent components <NUM>, each radially-expandable stent component <NUM> having proximal end <NUM> and distal end <NUM>, wherein at least one of stent components <NUM> includes struts <NUM>. As shown in <FIG>, struts <NUM> include opposite ends <NUM>, <NUM> and are joined to each other at respective opposite ends, thereby forming proximal apices <NUM> and distal apices <NUM>. Radially-expandable stent components <NUM> are arranged in relative proximal and distal relationship to each other, and are linked by plurality of bridges <NUM> between immediately proximal and distal radially-expandable stent components <NUM> to each other. Luminal stent assembly <NUM> also includes radially-expandable stents <NUM> distal to luminal stent <NUM>, at least one of a luminal graft component (not shown) and polymeric coating <NUM> at luminal stent, and balloon <NUM> within the luminal stent assembly <NUM> when in a collapsed position (not shown). Balloon <NUM> has a greater diameter D at proximal end <NUM> of luminal stent when inflated. As described above, diameters D, D' of balloon <NUM> can be stepped with distance between proximal end <NUM> and distal end <NUM>, whereby balloon <NUM> includes proximal diameter D, distal diameter D', and transition area <NUM> between proximal diameter D and distal diameter D'. Balloon <NUM> can be fabricated of any suitable material, such as a semi-compliant material. Radiopaque markers <NUM> are fixed to balloon <NUM>, and marker <NUM> is fixed to luminal stent <NUM> at junction area <NUM> of luminal stent assembly <NUM>. Transition area <NUM> of balloon <NUM> has transition length T.

In this version, axial stiffness of luminal stent <NUM> decreases from proximal end <NUM> and to distal end <NUM> by a suitable means, such as by a decrease in the number of bridges <NUM> spanning radially-expandable stent components <NUM>. Radial stiffness can also decrease with increasing distance from proximal end <NUM> of luminal stent <NUM> by a suitable means, such as by an increase in the length of struts <NUM> of radially-expandable stent components <NUM>, and a decrease in thickness of struts <NUM> of radially-expandable stent components <NUM> with distance from proximal end <NUM> of luminal stent <NUM>. In one such version, at least one of axial stiffness and radial stiffness of luminal stent <NUM> is stepped, wherein luminal stent <NUM> further includes incremental junction <NUM>, whereby radial stiffness of luminal stent <NUM> changes in at least one increment. In one such version, luminal stent <NUM> includes a plurality of incremental junctions (not shown), wherein at least one of the axial stiffness and the radial stiffness of luminal stent <NUM> decreases with increasing distance from proximal end <NUM> of luminal stent <NUM>.

As shown in <FIG>, proximal end 206a of balloon <NUM> is proximate to proximal end <NUM> of luminal stent assembly <NUM> and distal end of balloon 206b is proximate to distal end <NUM> of luminal stent assembly <NUM>. Upon inflation, balloon <NUM> exerts greater radial expansive force against an inside surface of luminal stent at proximal end <NUM> of luminal stent assembly <NUM> than at distal end <NUM> of luminal stent assembly <NUM>, thereby causing luminal stent to have a greater outside diameter at proximal end <NUM> than at distal end <NUM>, absent some constricting force at luminal stent <NUM>, such as would be applied at a fenestration in a fenestrated stent graft <NUM> in which luminal stent assembly <NUM> has been placed, as shown in phantom in <FIG>, and as shown in <FIG>, <FIG> and <FIG>, described infra. For example, as shown in <FIG>, inflation of balloon <NUM> is within fenestration <NUM> of fenestrated stent graft <NUM> will cause constriction of luminal stent <NUM> at fenestration <NUM> relative to the remainder of luminal stent <NUM> on either side of fenestration <NUM>. In one version, additional layers of polymer are included at distal end 206b of balloon <NUM> to prevent excessive radial expansion of distal end <NUM> of the luminal stent assembly <NUM> when the balloon is not protruding from the distal end of the stent, thereby keeping the distal end of the stent and the balloon from overdilating and, consequently, preventing damage to the vascular branch into which the luminal stent assembly <NUM> has been implanted.

In one version, radially-expandable stents <NUM> distal to luminal stent <NUM> in this embodiment has at least one of an axial stiffness and a radial stiffness less than that of luminal stent <NUM>. In one specific version, at least one radiopaque marker <NUM> is fixed to luminal graft component (not shown) or polymeric coating <NUM> between luminal stent <NUM> and radially-expandable stent <NUM> distal to luminal stent <NUM>. In this version, in one variation, luminal stent assembly <NUM> includes a variation in radial stiffness at luminal stent <NUM>, whereby radial stiffness is stepped, thereby forming junctures <NUM> at luminal stent <NUM>, and further including a second radiopaque marker <NUM> at at least one incremental juncture <NUM> of luminal stent <NUM>.

As discussed above with respect to earlier versions, radial stiffness of the radially-expandable stent <NUM> can be resistance to radial expansion from a radially collapsed position. In another version, the material in the radially-expandable stents <NUM> distal to luminal stent can be fabricated of the same material as that of luminal stent <NUM>. In such a version, not shown, the most proximal of the radially-expandable stent components can be flared at the proximal end of the luminal stent upon implantation, as will be described below.

Another version, the invention is a luminal stent assembly that includes a luminal stent and a polymeric coating at the luminal stent, either or the combination of which is collectively represented. In this version, shown in <FIG>, luminal stent assembly <NUM> has proximal end <NUM> and distal end <NUM>, and includes luminal stent <NUM> having a plurality of radially-expandable stent components <NUM>, as similarly indicated in <FIG>. In <FIG> and 20B, however, luminal graft component <NUM> of <FIG> is substituted with polymeric coating <NUM> that lines inside surface <NUM> and outside surface <NUM> of luminal stents <NUM>.

In one variant of the embodiment of <FIG>, shown in <FIG>, luminal stent <NUM> has proximal end <NUM> and distal end <NUM>, and includes at least a portion of radially-expandable stent components <NUM> that are nested. In this embodiment, radially-expandable stent components <NUM> can be linked by bridges <NUM> extending between respective proximal apices <NUM> and respective distal apices <NUM> of adjacent radially-expandable stent components <NUM>. In another embodiment, such as shown in <FIG>, luminal stent <NUM> includes proximal end 265a and distal end 265b, and is made up of radially-expandable stent components <NUM> and bridges <NUM> extending between only proximal apices <NUM>. In yet another embodiment, shown in <FIG>, lumina stent <NUM> has proximal end 273a and distal end 273b, and includes radially-expandable stent components <NUM> linked by bridges <NUM> only between distal apices <NUM> of proximate proximal and distal radially-expandable stent components <NUM>. In still another embodiments, such as is shown in <FIG>, in luminal stent assembly <NUM>, which includes proximal end 283a and distal end 283b, a combination of proxial apices 282a and distal apices 282b of nested radially-expandable stent component <NUM> can be linked. Optionally, the number of bridges <NUM> between radially-expandable stent components <NUM> diminishes with distance from the proximal end of the luminal stent. In such an embodiment, or in another embodiment, luminal stent assembly <NUM> can include distal stents <NUM> that are nested, but wherein radially-expandable stent components <NUM> of luminal stent <NUM> may or may not be nested. More specifically, in one embodiment, such as is seen in <FIG>, the degree of nesting of radially-expanding stent components <NUM> decreases with increasing distance from proximal end <NUM> toward distal end 283b of luminal stent assembly <NUM>, thereby decreasing the axial stiffness (or "bending stiffness") of luminal stent assembly <NUM> with increasing distance from proximal end <NUM>. S-shaped bridges 285a and 285b can bridge struts of radially-expandable stent component <NUM> of luminal stent <NUM>, either between radially-expandable stent components that are not nested, as shown in <FIG>, or between struts of nested immediately distal and proximal radially-expandable stents, not shown, to thereby control at least one of axial stiffness and radial stiffness.

In another version, shown in <FIG>, luminal stent assembly <NUM> includes luminal stent <NUM> of radially-expandable stents <NUM> that are not nested, wherein the radially-expandable stents <NUM> are linked by a polymeric coating <NUM>. It is to be understood that, in this version, either or both the axial stiffness and the radial stiffness can decrease with increasing distance from proximal end <NUM> to distal end <NUM> of luminal stent assembly <NUM>, either as a consequence of a decrease of either or both of respective decreasing axial and radial stiffness of radially-expandable stent <NUM> relative to each other.

In still another version, shown in <FIG>, luminal stent assembly <NUM> includes proximal end <NUM> and distal end <NUM>, and a plurality of radially-expandable stents <NUM>. Each radially-expandable stent <NUM> includes proximal end <NUM> and distal end <NUM>. Radially-expandable stents <NUM> include struts <NUM>. Struts <NUM> include opposite ends that are joined to each other to form proximal and distal apieces. Radially-expandable stents <NUM> are in relative proximal and distal relationship to each other. The radial stiffness of each radially expandable stent <NUM> is less than that of each radially-expandable stent <NUM> proximal to it, and greater than that of each radially-expandable stent <NUM> distal to it. Radially expandable stents <NUM> are linked by at least one of a luminal graft component (not shown) and polymeric coating <NUM>. Radially-expandable stents <NUM> are decreasingly nested with each other with increasing distance from proximal end <NUM> to distal end <NUM>.

As shown in <FIG> and <FIG>, luminal stent assembly <NUM>, shown partially implanted within a branched artery <NUM>, includes luminal stent <NUM> having a plurality of radially-expandable stent components <NUM> and plurality of bridges <NUM> linking immediately proximal and distal radially-expandable stent components <NUM> to each other. Radially-expandable stent components <NUM> each include struts <NUM> wherein the struts include opposite ends that are joined to each other at respective opposite ends, thereby forming proximal apices <NUM> and distal apices <NUM>, like apices previously described. Radially-expandable stent components <NUM> are arranged in relative proximal and distal relationship to each other and linked by bridges <NUM> at distal apices <NUM> and proximal apices <NUM>. Radially-expandable distal stents <NUM> are located distally to luminal stent <NUM>. At least one of a luminal graft component (not shown) and polymeric coating <NUM> are at luminal stent. Balloon <NUM> extends within luminal stent <NUM> when luminal stent <NUM> is in a collapsed position, as shown in <FIG>, and has a greater diameter at a proximal end than at a distal end when inflated, as shown at <FIG>. Fenestrated stent graft <NUM> defines at least one fenestration <NUM>, wherein luminal stent <NUM> at proximal end <NUM> has a diameter less than fenestration <NUM> when in a collapsed position, shown in <FIG>, and is expandable to a diameter that fixes luminal stent <NUM> within fenestration <NUM>, whereby distal end <NUM> of luminal stent assembly <NUM> extends radially from fenestrated stent graft <NUM> into branch <NUM> of branched artery <NUM>, as shown in <FIG>.

<FIG> is an exploded side view of another version. Stent graft delivery system <NUM> as described below is based on the teaching of <CIT>. More specifically, stent graft delivery system <NUM> includes guidewire catheter <NUM> having proximal end <NUM> and distal end <NUM>. Proximal handle <NUM> is fixed to proximal end <NUM> of guidewire catheter <NUM>. Nose cone <NUM> is fixed to distal end <NUM> of guidewire catheter <NUM>. Wire <NUM> includes proximal end <NUM> and distal end <NUM>. Wire <NUM> can be fabricated of a suitable material, such as is known in the art, including, for example, Nitinol or some other shape memory alloy, or stainless steel. Wire <NUM> is sufficiently flexible not to injure the patient during advancement to an aortic aneurysm of a patient. Wire handle <NUM> is fixed at proximal end <NUM> of wire <NUM>. Introducer sheath <NUM> includes proximal end <NUM> and distal end <NUM>, and distal handle <NUM> is fixed to proximal end <NUM> of introducer sheath <NUM>. Stent graft <NUM> includes proximal end <NUM>, distal end <NUM>, luminal graft component <NUM>, stents <NUM> distributed along luminal graft component <NUM>, and ligatures <NUM>, as described in <CIT>.

<FIG> is an assembled side view of stent graft delivery system <NUM> shown in <FIG>, wherein stent graft <NUM> has been loaded within distal end <NUM> of introducer sheath <NUM>, and radially constricted, at least in part, by wire <NUM> threaded through loops <NUM> at ends of ligatures <NUM>, as discussed in <CIT>, and through stabilizing anchor loops <NUM>. Stent graft <NUM> can include fenestration <NUM>. In a method stent graft delivery system <NUM> is advanced to arterial aneurysm <NUM> of a patient. In one version, shown in <FIG>, introducer sheath <NUM> is advanced to aneurysm site <NUM> to thereby place stent graft <NUM> at arterial aneurysm <NUM>. As can be seen in <FIG>, distal handle <NUM> is retracted in a proximal direction indicated by arrow <NUM> toward proximal handle <NUM>, thereby retracting introducer sheath <NUM> from stent graft <NUM> at aneurysm <NUM>. As can be seen in <FIG>, despite retraction of introducer sheath <NUM>, stent graft <NUM> is maintained in a radially constricted position by wire <NUM> extending through ligature loops <NUM> of ligatures <NUM> traversing struts of stents <NUM> distributed longitudinally along stent graft <NUM>. It is to be understood, however, that in alternative methods, stent graft delivery system <NUM> can be advanced within an artery to a position distal to arterial aneurysm <NUM>, wherein stent graft <NUM> is directed to arterial aneurysm <NUM> by advancement of proximal handle <NUM> and wire handle <NUM> in a distal direction indicated by arrow <NUM> toward distal handle <NUM> to thereby direct radially-constricted stent graft <NUM> from introducer sheath <NUM> to arterial aneurysm <NUM>.

Following direction of stent graft <NUM> to a position that spans aneurysm <NUM>, and at least partial rotational and axial alignment of stent graft <NUM> at aneurysm <NUM>, wire <NUM> is partially retracted from loops <NUM> of ligatures and from anchor loops <NUM>. Proximal retraction of wire handle <NUM> toward proximal handle <NUM>, in the direction indicated by arrow <NUM>, can be seen in <FIG>. Continued retraction of wire <NUM> withdraws wire <NUM> from all suture loops <NUM> of ligatures <NUM> and anchor loops <NUM>, thereby enabling stent graft <NUM> to fully expand from its radially constricted state, shown in <FIG>, to a radially expanded state, shown in <FIG>. Stent graft <NUM> is positioned so that fenestration <NUM> is properly aligned with arterial branch <NUM> for subsequent placement of branch prosthesis <NUM> through fenestration <NUM> to arterial branch <NUM>. Thereafter, stent graft <NUM> is fully implanted within aneurysm, and the remainder of stent graft delivery device <NUM> is retracted from stent graft <NUM> and the patient, as shown in <FIG>, thereby completing treatment of aneurysm site <NUM> of the patient.

Vascular prostheses implanted by the stent graft systems and methods can be implanted, for example, by transfemoral access. Additional branch prostheses that are directed into the vascular prostheses can be implanted, for example, by supraaortic vessel access (e.g., through the brachial artery), or by transfemoral access, or access from some other branch or branches of major blood vessels, including peripheral blood vessels.

In a method of implanting a stent graft system, a fenestrated stent graft of the stent graft system is delivered to a branched artery in a subject, wherein a fenestration defined by the fenestrated stent graft aligns with the proximal end of the branched artery. A luminal stent or luminal stent assembly is delivered through the fenestration and into an arterial branch, wherein the luminal stent or the luminal stent of the luminal stent assembly has a proximal end at the fenestration of the fenestrated stent graft and a distal end extending radially outward from the fenestrated stent graft, as shown in <FIG>. The luminal stent is radially expanded within the fenestration and the arterial branch by inflating a balloon within the luminal stent that has a greater diameter at the proximal end of the luminal stent than at the distal end of the luminal stent, thereby implanting the stent graft system, as represented above in <FIG>, <FIG> and <FIG>.

In one example, the luminal stent of the stent graft system implanted by the method includes, as described in detail above, a plurality of radially-expandable stent components, wherein the radially expandable stent components are joined at respective ends, thereby forming proximal apices and distal apices, the radially expandable stents being arranged in relative proximal and distal relationship to each other to thereby form a luminal stent defining a continuous luminal, a proximal end and a distal end of the luminal stent. The luminal stent in this example also includes a plurality of bridges, each of which link a relatively proximal radially-expandable stent component to an immediately distal radially-expandable stent component, wherein the luminal stent has at least one of an axial stiffness and a radial stiffness that decreases with increasing distance from the proximal end of the luminal stent. In one such example, the axial stiffness of the luminal stent decreases from the proximal end to the distal end of the luminal stent consequent to a decrease in the number of bridges spanning the radially-expandable stent components, and optionally or in the alternative, radial stiffness decreases with increasing distance from the proximal end of the luminal stent by at least one of an increase in the length of the struts of the radially-expandable stent components and a decrease in thickness of the struts of the radially expandable stent components with distance from the proximal end of the luminal stent. All of which is described in detail above.

In another example of a method of implanting a stent graft system, a fenestrated stent graft of the stent graft system, such as is described in detail above, is delivered to a branched artery of a subject, wherein fenestration defined by the fenestrated stent graft aligns with a proximal end of a branched artery of a patient. A luminal stent assembly of a stent graft system is delivered at least partially through the fenestration and into the arterial branch, the luminal stent assembly thereby bridging the fenestrated stent graft and arterial branch, whereby the luminal stent assembly includes a plurality of stents aligned longitudinally and connected by bridges to form a luminal stent. At least one stent distal to the luminal stent has a radial stiffness less than that of the luminal stent. At least one of a luminal graft component and a polymeric coating links the luminal stent and the stent distal to the luminal stent. The luminal stent assembly is radially expanded within the fenestration of the arterial branch by inflating a balloon within the luminal stent assembly, wherein the balloon has a greater diameter at the luminal stent than at the distal stent to the luminal stent when inflated, thereby fixing the luminal stent within the fenestration and implanting the stent graft system. All of which is described in detail above.

In one example of this method, the stent distal to the luminal stent is linked to the luminal stent by the luminal graft component. In another example, the stent distal to the luminal stent is linked to the luminal stent by the polymeric coating. In still another embodiment, the polymeric coating encapsulates the luminal stent and the stent distal to the luminal stent. In still another embodiment, at least one of the stent distal to the luminal stent and the luminal stent defines openings, and the polymeric coating seals the openings and defines a luminal space between the stent distal to the luminal stent and the luminal stent. All of which is described in detail above.

Once radially-expanded within fenestrated stent graft, such as is shown in <FIG>, luminal stent assembly <NUM> includes luminal stent <NUM> that is flared at proximal end <NUM>. Flaring at proximal end <NUM> can be obtained by inflation of a balloon, as previously described, within luminal stent assembly <NUM>, while proximal end <NUM> is within fenestration <NUM> of fenestrated stent graft <NUM> that has previously been implanted in a branched artery <NUM> in a subject in order to, for example, secure proximal end <NUM> of luminal stent assembly <NUM> within fenestration <NUM> of the fenestrated stent graft <NUM>. As can be seen in <FIG>, proximal end <NUM> of luminal stent assembly <NUM> is covered by polymeric coating <NUM>, while luminal stent <NUM> is exposed, or bare, at distal end <NUM> of luminal stent assembly <NUM>.

Claim 1:
A luminal stent assembly (<NUM>), comprising:
a) a luminal stent (<NUM>) including,
i) a plurality of radially-expandable stent components (<NUM>), each radially-expandable stent component having a proximal end and a distal end, at least one of the stent components including struts, wherein the struts include opposite ends and are joined to each other at the respective opposite ends, thereby forming proximal apices and distal apices, the radially-expandable stent components (<NUM>) being in relative proximal and distal relationship to each other, and
ii) a plurality of bridges (<NUM>) linking immediately proximal and distal radially-expandable stent components (<NUM>) to each other, thereby forming the luminal stent (<NUM>) and defining a continuous lumen, a proximal end, and a distal end of the luminal stent (<NUM>);
b) at least one of a luminal graft component (<NUM>) and a polymeric coating (<NUM>) at the luminal stent (<NUM>); and
c) at least one stent distal (<NUM>) to the luminal stent (<NUM>) and linked to the luminal stent (<NUM>) by at least one of the luminal graft component (<NUM>) and the polymeric coating (<NUM>) to thereby form the luminal stent assembly (<NUM>), the luminal stent assembly (<NUM>) having a proximal end at the luminal stent (<NUM>) and a distal end at the stent distal to the luminal stent (<NUM>),
wherein axial stiffness of the luminal stent assembly (<NUM>) decreases from the proximal end to the distal end of the luminal stent assembly (<NUM>) as a consequence of a space between the luminal stent (<NUM>) and the at least one stent distal to the luminal stent, and the radial stiffness of the luminal stent (<NUM>) is greater than the radial stiffness of the at least one distal stent; and
wherein at least a portion of the radially-expandable stent components (<NUM>) are nested.