JP5537540B2 - Double wall stent system - Google Patents

Description

  The present invention relates to an intraluminal stent for use in a body lumen. In particular, the present invention relates to a double wall stent system.

  Heart valves, such as mitral, tricuspid, aortic, and pulmonary valves, can sometimes be damaged by disease or aging, causing problems that prevent the heart valve from functioning properly. Heart valve problems generally have two forms: a stenosis where the valve does not open at all or opens too little and restricts blood flow, and a dysfunction in which blood flows back through the valve when the valve should be closed Is one form.

  The pulmonary valve controls blood flow between the right ventricle and the pulmonary artery to control blood flow between the heart and the lungs. Pulmonary valve stenosis is often due to narrowing of the pulmonary valve or the pulmonary artery distal to the valve. This narrowing places great pressure on the right side of the heart to supply enough blood to the lungs. Eventually, the right ventricle enlarges, leading to congestive heart failure (CHF). In severe cases, CHF results in clinical symptoms including shortness of breath, fatigue, chest pain, syncope, heart murmur, and insufficient weight gain (in infants). Pulmonary valve stenosis most commonly results from birth defects and is seen at birth, but is also associated with rheumatic fever, endocarditis, and other symptoms that cause damage and scarring to the pulmonary valve. In severe cases, valve replacement may be necessary to restore cardiac function.

  Previously, valve repair or replacement required open heart surgery that is risky, expensive, and time consuming to recover. Open heart surgery also requires cardiopulmonary bypass with the risk of thrombosis, stroke, and infarction. A variety of implantable pulmonary valve prostheses, delivery devices, and surgical techniques have been developed and are currently used to address the demands of pulmonary valve replacement. One such prosthesis is a biological valve conduit having a natural trilobal vein valve and a glutaraldehyde-treated bovine jugular vein containing a sinus. A similar device consists of a porcine arterial valve sutured in the center of the fabric conduit. A common conduit used for valve replacement is an allograft, which is a blood vessel collected from a cadaver. Valve replacement using either of these devices requires thoracotomy and cardiopulmonary bypass.

  As noted above, pulmonary valve stenosis most commonly occurs in infants and young children when symptoms arise from congenital abnormalities. Often the pulmonary valve must be replaced with a prosthetic valve when the child is small, usually under 5 years of age. However, as the child grows, the valve will become too small to keep the blood flow to the lungs necessary to meet the growing energy demand of the growing child and must be replaced with a larger valve Let's go. Alternatively, for patients of any age, over time, the accumulation of calcium can cause the implanted valve to malfunction and require replacement. In either case, repeated surgery or transvenous surgery is required.

  If the prosthetic valve must be replaced for the reasons described above or for other reasons, additional surgery is required. Because many patients undergo initial surgery at an extremely young age, such patients often undergo a number of operations before reaching adulthood. These surgical replacements are physically and mentally burdensome, and many patients choose to forego further surgery at an age when they can make their own medical decisions.

  In recent years, flexible stent-valve prostheses and various delivery devices have been developed to allow the delivery of replacement valves intravenously using a catheterized delivery system. These stent valves comprise a collapsible valve mounted inside a tubular frame or stent. This valve may be any valve prosthesis described above, or any other suitable valve. The stent-valve can also include a tubular portion or “stent graft” that can be attached to the inside or outside of the stent to define a generally tubular interior passage for blood flow when the leaflet is opened. . The graft can be separated from the valve and from any suitable biocompatible material including, but not limited to, fabrics, allografts, porcine blood vessels, bovine blood vessels, and horse blood vessels. Can be formed. The stent portion of the device can be attached to the catheter with a reduced diameter to advance the patient's circulatory system. The stent portion can be either self-expanding or balloon expandable. In either case, the stent-valve is placed at the delivery site, where the stent portion is expanded against a pre-implanted prosthesis or natural vessel wall to keep the valve firmly in place. Can do. The valve withstands compression and subsequent fully actuated forms of expansion. One embodiment of a stent valve is disclosed in US Pat. No. 5,957,949 entitled “Percutaneous Placement Valve Stent” by Leonhardt et al., Which is hereby incorporated by reference in its entirety. Although the valve may require subsequent replacement, the patient can undergo multiple valve replacements with minimally invasive catheterization without the need for further invasive surgery.

  It is an object of the present invention to disclose a stent system for addressing abnormalities and / or growth of the right ventricular outflow tract. The stent system can be delivered intravenously using a catheter delivery system.

  Embodiments of the invention relate to a stent system for use in a body lumen. The stent system includes an inner stent element having a proximal end, a distal end, and a generally tubular cylindrical body defining a central flow path lumen therethrough. The stent system also includes an outer stent element having a plurality of longitudinally extending connectors disposed radially about the tubular body of the inner stent element. The outer stent element is slidably attached to the inner stent element in a non-stick manner. When the stent system has a radially expanded geometry, the longitudinally extending connector of the outer stent element is curved radially outward relative to the vessel wall of the body lumen. And the inner stent element is located radially within a connector extending longitudinally of the outer stent element.

  The above and other features and advantages of the present invention will become apparent from the detailed description which is illustrated in the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this specification, further serve to illustrate the principles of the invention and to enable those skilled in the art to make and use the invention. . The drawings are not to scale.

1 is a perspective view showing a double wall stent system having an outer stent element and an inner stent element according to an embodiment of the present invention. FIG. FIG. 6 is a side view of an outer stent element according to an embodiment of the present invention. FIG. 6 is an enlarged plan view showing a portion of an outer stent element according to another embodiment of the present invention. FIG. 6 is an enlarged plan view showing a portion of an outer stent element according to another embodiment of the present invention. FIG. 4 is a side view of an inner stent element according to an embodiment of the present invention. 1 is a side view of a stent system having an outer stent element and an inner stent element coupled to each other according to an embodiment of the present invention. FIG. FIG. 6 is a side view of an outer stent element according to another embodiment of the present invention. FIG. 6 is a side view of an inner stent element according to another embodiment of the present invention. FIG. 6 is a side view of a stent system having an outer stent element and an inner stent element joined together by a snap fit connection according to another embodiment of the present invention. FIG. 5 is an enlarged plan view showing the snap fit coupling of FIG. 4. FIG. 7 is an enlarged plan view illustrating another embodiment of a snap fit connection between an outer stent element and an inner stent element. FIG. 6 is an enlarged plan view illustrating an interference connection between an outer stent element and an inner stent element according to another embodiment of the present invention. 1 is a side view of a stent system in a contracted or compressed geometry. FIG. 1 is an end view of a stent system in a contracted or compressed geometry. FIG. FIG. 5 is a side view of a deployed stent system in an expanded or expanded geometry. 1 is an end view of a deployed or expanded geometric stent system. FIG. 1 is a side view illustrating a delivery system of a balloon expandable stent system according to an embodiment of the present invention. FIG. FIG. 7 shows a laser cut sub-element for forming the inner stent element shown in FIG. FIG. 6 shows a laser cut sub-element for forming the outer stent element shown in FIG. FIG. 3 is a diagram illustrating flow through a double wall stent system according to an embodiment of the present invention. FIG. 6 is a diagram illustrating flow through a double wall stent system according to another embodiment of the present invention. FIG. 6 is a side view of an outer stent element in a deployed or expanded geometry according to another embodiment of the present invention. FIG. 7 is a side view of an deployed or expanded geometric inner stent element according to another embodiment of the present invention. FIG. 6 is a side view of an outer stent element according to another embodiment of the present invention. FIG. 22 is a side view of a double wall stent system with the inner stent element of FIG. 20 and the outer stent element of FIG. 21 in a deployed or expanded geometry. FIG. 23 is an end view of the double wall stent system of FIG. FIG. 6 is a side view of a deployed or expanded geometric double wall stent system according to another embodiment of the present invention. FIG. 6 is a side view of an outer stent element according to another embodiment of the present invention. FIG. 26 is a side view of a double wall stent system with the inner stent element of FIG. 20 and the outer stent element of FIG. 25 in an expanded or expanded geometry. FIG. 27 is an end view of the double wall stent system of FIG. 26. FIG. 6 shows a laser cut subelement for forming an outer stent element according to another embodiment of the present invention. FIG. 6 shows a laser cut subelement for forming an outer stent element according to another embodiment of the present invention. FIG. 30 is a side view of an outer stent element formed based on the laser cut subelement of FIG. 29. FIG. 6 shows a laser cut subelement for forming an outer stent element according to another embodiment of the present invention. FIG. 4 shows an inner stent element with a valve disposed therein according to an embodiment of the present invention. 1 is a side view of an expanded geometric double wall stent system according to an embodiment of the present invention. FIG. FIG. 34 is a cross-sectional view of the double wall stent system of FIG. 33 taken along line AA of FIG. FIG. 34 is an end view of the double wall stent system of FIG. 33 in an expanded geometry. 1 is a side view of a segmented double wall stent system according to an embodiment of the present invention in a contracted or compressed geometry. FIG. FIG. 36 is a side view of the segmented double wall stent system of FIG. 35 in a contracted or compressed geometry. FIG. 22 is a side view of the outer stent element of FIG. 21 with an intermediate connector or tether between adjacent longitudinally extending connectors according to an embodiment of the present invention. FIG. 38 is a side view of a double wall stent system with the inner stent element of FIG. 20 and the outer stent element of FIG. 37 in an expanded or expanded geometry. 1 is a side view of a floating double wall stent system according to an embodiment of the present invention in an expanded geometry. FIG. FIG. 40 is an end view of the floating double wall stent system of FIG. 39. FIG. 6 is a side view of a floating double wall stent system according to another embodiment of the present invention in an expanded geometry. FIG. 41 is an end view of the floating double wall stent system of FIG. 40.

  Certain embodiments of the present invention will now be described with reference to the drawings, wherein like reference numerals indicate identical or functionally similar elements. The terms “distal” and “proximal” are used in the following description of the position or orientation relative to the treating clinician. “Distal” or “distal” is the position away from or away from the clinician. “Proximal” or “proximal” is a position close to or toward the clinician.

  The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses thereof. Although the description of the present invention is in the context of the treatment of blood vessels such as coronary, carotid, and renal arteries, the present invention can be used with any other body passage that is deemed useful. Furthermore, there is no intention to be bound by any expressed or implied theory in the preceding technical field, background, brief description or the following detailed description.

  Embodiments of the present invention relate to a double wall stent system comprising two stent elements, an outer stent element and an inner stent element. The double wall stent system has a contracted or compressed geometry sufficient to deliver to the treatment site and an expanded or deployed geometry to contact the vessel wall. When deployed, the outer stent element contacts the vessel wall and helps secure the stent system to the treatment site. In addition, the outer stent element provides a scaffold that supports the vessel wall. The inner stent element also expands but remains centered inside the outer element. The inner stent element is located at the radial center within the vessel lumen, i.e., at the center of the lumen, with little or no contact with the vessel wall. The surface of the inner stent element can be covered with a material such as a graft so that the inner stent element defines a central channel lumen that guides blood flow through the center of the stent system. When properly implanted within a blood vessel, blood flow is guided to the central flow channel lumen defined by the inner stent element without moving to the outer wall of the outer stent element. Thus, the inner stent element provides the stent system with a matched central channel lumen of a predetermined expansion diameter, such as a diameter that matches the normal diameter of the vessel, to maintain blood flow through the vessel in which the stent system is implanted. To do. In addition, the central channel lumen of the inner stent element can accommodate a second device, such as a valve, therein. At the same time, the outer stent element provides the stent system with a large outer diameter that may conform to the vessel wall and provide a force against the vessel wall, which in some embodiments may be variable.

  Separation between the central flow path lumen defined by the inner surface of the inner stent element and the outer diameter defined by the outer surface of the outer stent element provides a valve in a relatively large size and / or irregularly shaped vessel. A second device having a constant diameter such as can be arranged. More specifically, the double wall structure of the stent system provides a degree of mechanical separation between the inner wall of the stent system defined by the inner stent element and the outer wall of the stent system defined by the outer stent element. As used herein, mechanical separation means that the outer wall of the stent system minimizes or separates the inner wall of the stent system from or against the mechanical force applied to the stent system from the vessel wall. By reducing the likelihood that the shape or size of the central flow path lumen of the stent system defined by the stent element will be altered. The outer stent element conforms to the vessel wall of a relatively large and / or irregularly shaped blood vessel and provides the necessary force against the vessel wall against this vessel wall. Because the inner stent element is protected or separated from the vessel wall, it can hold a second device having a constant diameter, such as a valve. The ability to deploy a double-walled stent system within an irregularly shaped vessel to maintain a central channel lumen at a uniform diameter that matches the dimensions of the proximal and distal vessels at the implantation site It is important to guide blood flow into the stent system and to ensure proper valve placement where applicable. For example, where a double wall stent system is used in the right ventricular outflow tract, it may be desirable to include a valve within the inner stent element to control flow through the inner stent element. When the valve is used within an inner stent element, the inner stent element must function as a blood flow conduit that guides blood flow through the center of the device and blocks blood flow from the outer wall of the stent system. is there. The double-wall stent system treats the right ventricular outflow tract so that the outer stent element allows patient growth and / or adapts to body lumen abnormalities and reduces the number of replacements required. Especially suitable for. In addition to addressing abnormalities in the right ventricular outflow tract, the double wall stent system is useful for other vascular disorders that require juxtaposition to close the space while maintaining the central channel lumen, such as vasodilation, arteries, etc. It can be used to deal with aneurysms or other vascular congenital anomalies that are morphologically similar. Further details and description of embodiments of the present invention are set forth below with reference to FIGS.

33, 33A, and 34 illustrate an embodiment of a double wall stent system 3300. Stent system 3300 includes two stent elements, one outer stent element 3302 and one inner stent element 3304, one disposed over the other and forming a generally cylindrical body having _a common axis La. The outer stent element 3302 includes an outer surface that defines the outer diameter of the stent system 3300, and the inner stent element 3304 defines an inner diameter of the stent system 3300 and a central channel lumen 3421 therethrough. The central channel lumen 3421 has a consistent predetermined dilatation diameter to maintain blood flow therethrough. For example, the consistent predetermined expansion diameter can be approximately the same as the normal diameter of the body vessel in which the stent system is implanted. Inner stent element 3304 has a cylindrical tubular body extending between proximal end 3330 and distal end 3332. The inner stent element 3304 can be any suitable stent structure known to those skilled in the art and can include a valve (not shown) disposed therein.

Outer stent element 3302 includes a plurality of longitudinally extending bands or spar 3328. The band 3328 is a generally straight strip or support plate material that extends from the proximal end 3330 to the distal end 3332 of the inner stent element 3304 parallel to _a common longitudinal axis La. It is. More specifically, the proximal end of each longitudinally extending band 3328 is coupled to the proximal proximal end 3330 of the inner stent element 3304 and each of the longitudinally extending bands 3328 is The distal end is connected to the proximal distal end 3332 of the inner stent element 104. Band 3328 has a length approximately equal to the length of the tubular body of inner stent element 3304. Inner stent element 3304 is located in the radial center or interior of band 3328 of outer stent element 3302 and is welded or any other suitable for connecting outer stent element 3302 and inner stent element 3304. Attached to outer stent element 3302 by a method.

  The longitudinally extending band 3328 of the outer stent element 3302 is expanded or radially expanded by the forening dynamics of the inner stent element 3304. More specifically, the inner stent element 3304 is designed to undergo a certain amount of shortening or contraction that reduces the length of the inner stent element upon radial expansion. Thus, during radial expansion of the stent system 3300, the inner stent element 3304 expands in diameter and shortens in length, which causes the band 3328 to bulge or curve outward toward the vessel wall. As the proximal and distal ends of the band 3328 approach each other when the inner stent element 3304 is shortened, the deployed band 3328 of the outer stent element 3302 curves radially outward to contact the vessel wall, Helps secure stent system 3300 to the treatment site. The inner stent element 3304 expands radially such that the central channel lumen 3421 reaches the expanded diameter, but the outer surface of the inner stent element 3304 has little or no contact with the vessel wall, rather within the outer stent element 3302. Maintained in the center of the radial direction. The inner stent element 3304 is configured such that the central channel lumen 3421 has a diameter that substantially matches the proximal and distal vessel dimensions of the implanted stent system 3300.

  In another embodiment of the present invention, the double wall stent system provides a plurality of variable outer diameters to the stent system that conform to the vessel wall and provide a force against the vessel wall. It can comprise segments, i.e. individual parts or zones. For example, the double wall stent system 3500 shown in FIG. 35 includes an outer stent element 3502 having three separate segments 3541, 3543, and 3545, each with a plurality of independent longitudinally extending bands. It has. Segments 3541, 3543, and 3545 are separately attached to an inner stent element 3504 having three corresponding separate portions: a proximal portion 3523, an intermediate portion 3525, and a distal portion 3527. The outer surfaces of segments 3541, 3543, and 3545 define the outer diameter of stent system 3500 that may vary from segment to segment when expanded. The cylindrical tubular body of the inner stent element 3504 having a proximal portion 3523, an intermediate portion 3525, and a distal portion 3527 provides a central channel lumen (not shown) therethrough that provides the inner diameter of the stent system 3500. Defined. Each portion 3523, 3525, and 3527 of the inner stent element 3504 can be designed to shorten to the same or different degrees upon expansion, in other words, larger than the other portions based on the strut design, It can have a small or equal shrinkage. In various embodiments, the outer stent element 3502 and the inner stent element 3504 can have any number of corresponding segments or portions depending on the desired operation of the stent system 3500.

  Each segment 3541, 3543, and 3545 of the outer stent element 3502 is a generally straight line extending from the proximal end to the distal end of the corresponding portion 3523, 3525, and 3527 of the inner stent element 3504, respectively. It comprises a plurality of longitudinally extending bands or spars that are the material of the strip or support plate. More specifically, a plurality of independent longitudinally extending bands 3628 A that make up segment 3541 are disposed radially about proximal portion 3523 of inner stent element 3504. Each proximal end of the longitudinally extending band 3628A is coupled to the proximal end of the proximal portion 3523, and each distal end of the longitudinally extending band 3628A is coupled to the proximal portion. Connected to the distal end of 3523. Similarly, a plurality of independent longitudinally extending bands 3628 B that make up segment 3543 are radially disposed about an intermediate portion 3525 of inner stent element 3504. Each proximal end of the longitudinally extending band 3628B is coupled to the proximal end of the intermediate portion 3525, and each distal end of the longitudinally extending band 3628B is connected to the intermediate portion 3525. Connected to the distal end. In addition, a plurality of longitudinally extending bands 3628C constituting segment 3545 are radially disposed about distal portion 3527 of inner stent element 3504. Each proximal end of the longitudinally extending band 3628C is coupled to the proximal end of the distal portion 3527, and each distal end of the longitudinally extending band 3628C is coupled to the distal portion. Connected to the distal end of 3527.

  In the embodiment illustrated in FIGS. 35 and 36, the intermediate portion 3525 of the inner stent element 3504 has a strut design that has a relative shortening when expanded compared to the proximal portion 3523 and the distal portion 3527. The difference in the degree of shortening between portions 3523, 3525, and 3527 results in a difference in the expansion height of segments 3541, 3543, and 3545 of outer stent element 3502. More specifically, segments 3541, 3543, and 3545 of outer stent element 3502 are deployed or radially expanded by shortening dynamics of corresponding portions of inner stent element 3504. Due to the greater relative amount of shortening experienced by the proximal portion 3523 and the distal portion 3527 of the inner stent element 3504, the segments 3541 and 3545 of the outer stent element 3502 are more radial than the segment 3543 connected to the corresponding intermediate portion 3525. Expands or curves outward. The number of segments and stent portions with various shortening ratios customizes the different expanded heights of the segments to provide the least force in the thin area of the vessel wall and the maximum for the portion where the vessel wall can maintain greater force Can be selected to obtain the intended structure and dimensions of the target implantation region.

Referring to FIG. 1, a perspective view of a double wall stent system 100 according to another embodiment of the present invention is shown. Stent system 100 includes two stent elements: an outer stent element 102 and an inner stent element 104. The inner stent element 104 has a generally tubular cylinder having a plurality of stent struts connected to each other and is located in the center or interior of the outer stent element 102. The outer stent element 102 and the inner stent element 104 are manufactured as independent separating elements that can be connected to each other by soldering, welding, or other attachment means. Outer stent element 102 and inner stent element 104 are aligned relative to _a common longitudinal axis La to form a generally cylindrical tubular body having a radial axis and a longitudinal axis.

With reference to FIG. 2, the outer stent element 102 has a proximal portion 208 and a distal portion 218. Proximal portion 208 includes a generally cylindrical stent strut 210 and distal portion 218 includes a generally cylindrical stent strut 220. Proximal stent strut 210 and distal stent strut 220 are aligned by _a common longitudinal axis La and are connected by a plurality of longitudinally extending connectors, such as straight band 228. Longitudinal axis L _a extends into the cylindrical body from the proximal end 212 of the outer stent element 102 to the distal end portion 222. Linear band 228 to couple the proximal stent strut 210 and distal stent struts 220, extending from the proximal portion 208 of the outer stent element 102 parallel to the common longitudinal axis L _a to the distal portion 218 The material of the existing generally straight strip or support plate. In the embodiment shown in FIG. 2, each of the straight bands 228 has approximately the same width.

  In another embodiment of the invention, the width of the connector extending in the first longitudinal direction may be different from the width of the connector extending in the second longitudinal direction. For example, FIG. 2A illustrates an enlarged plan view of a portion of an outer stent element 102A that includes a plurality of longitudinally extending connectors 228A. The first band 235 has a width W1, the second band 237 has a width W2, and W1 is larger than W2. By forming connectors extending in the longitudinal direction with different widths, the fixation of the stent system within the vessel wall is improved, and the connectors extending in the longitudinal direction with variable widths are matched with the constraints of the vessel wall Can do. By changing the surface area of the connector extending in the longitudinal direction, the force is distributed over a larger installation area, damage to the blood vessel wall is reduced, and fixation is improved. For example, a device with longitudinally extending connectors of various widths around the device provides an option to place the device in a blood vessel in a particular orientation. This may be particularly advantageous for vessels having both thin and thick vessel walls, as the device can be placed in the vessel in the proper orientation to minimize damage to the thin vessel wall region.

  Referring again to FIG. 2, the stent strut 210 of the proximal portion 208 of the outer stent element 102 has a corrugated or sinusoidal cylindrical band or ring having a pattern of crowns 214 and straight segments 219 connecting adjacent straight segments 219. It is. For purposes of this application, it should be understood that the crown is a concave turn or curve of a wavy or sinusoidal band. The straight segments 219 and the crown 214 of the stent strut 210 do not necessarily have to be connected to each other at the ends, but may continue to each other, i.e. be continuous. Other embodiments may be variously formed so that some parts can be mechanically connected to each other by welding, solder, adhesive, another bonding method, or another mechanical connection method. Can do. However, to describe the particular structure of stent strut 210, the various segments and crowns can be described as being connected or coupled together. Thus, the terms "coupled with", "coupled", or "coupled" mean either following one another, i.e., either continuous or mechanically coupled to one another. . Similar to stent strut 210, stent strut 220 at distal portion 218 of outer stent element 102 is a wavy or sinusoidal cylindrical band or ring having a pattern of crowns 224 and straight segments 229 connecting adjacent straight segments 229. It is. In one embodiment, stent struts 210, 220 each comprise eight crowns, but it will be apparent to those skilled in the art that the number of crowns may be varied.

As described above, the straight band 228 is a generally straight strip or support that extends from the proximal end 212 to the distal end 222 of the outer stent element 102 parallel to _a common longitudinal axis La. The material of the board. More specifically, each proximal end of the longitudinally extending straight band 228 is connected to a trough 216 of the crown 214 of the stent strut 210 and each distal end of the straight band 228 is The stent strut 220 is connected to the opposite valley 226 of the crown 224. For the purposes of this application, it should be understood that a trough is an open curved portion, or hollowed out portion, formed by a corrugated or sinusoidal band crown. Since the longitudinally extending connector extends from the proximal stent strut trough to the distal stent strut trough, it may be referred to as a “valley-to-valley” connector. The valley-to-valley connector, i.e., the straight band 228, extends the length of the inner stent element 104 to the length of the stent struts 210 and 220 so that the inner stent element 104 can be centered between the stent struts 210 and 220. It has a length approximately equal to the added length. In one embodiment, outer stent element 102 includes a total of eight longitudinally extending linear bands 228.

In another embodiment of the present invention, the connector extending in the longitudinal direction is not parallel to the common longitudinal axis L _a. For example, FIG. 2B illustrates an enlarged plan view of a portion of the outer stent element 102B with a plurality of longitudinally extending connectors 228B. Connector 228B is a strip or support plate material that connects proximal portion 208B of outer stent element 102B to distal portion 218B to connect proximal stent strut 210B and distal stent strut 220B. Connector 228B, instead of extending parallel to the common longitudinal axis L _a, is oblique, i.e. inclined to the common longitudinal axis L _a. More specifically, the proximal end of each connector 228B is spaced apart and connected to the adjacent valley of stent strut 210B, while the distal end of each connector 228B is one of stent struts 220B. It is connected by overlapping the crown. The inclination or angle of the connector 228B can help stabilize the expanded connector 228B, thereby applying additional force to the vessel wall to help secure the stent system to the treatment site.

Referring now to FIG. 3, the inner stent element 104 is a cylindrical tubular body having _a common longitudinal axis La, _a proximal end 330, and a distal end 332. Longitudinal axis L _a extends into a cylindrical body from the proximal end 330 of the inner stent element 104 to the distal end portion 332. The stent struts 334 to a plurality of proximity, in order to form the shape of a cylindrical tubular body of the inner stent element 104, it is substantially aligned parallel to the longitudinal axis L _a. FIG. 3 shows the inner stent element 104 having six stent struts 334 connected by a connecting portion 342. One skilled in the art will appreciate that the inner stent element 104 can have any number of stent struts 334 depending on the desired length of the stent system 100.

  Each stent strut 334 is a wavy or sinusoidal cylindrical band or ring having a pattern of crowns 338 and straight segments 339 connecting adjacent straight segments 339. For purposes of this application, it should be understood that the crown is a concave turn or curve of a wavy or sinusoidal band. The straight segments 339 and crown 338 of each wavy or sinusoidal cylindrical band do not necessarily have to be joined to each other at the ends, but may follow each other, i.e. be continuous. Each stent strut 334 is functionally the same in that each has a substantially similar pattern of straight segments 339 and crown 338. Adjacent stent struts 334 are aligned such that the crown of one strut aligns with the corresponding crown of the adjacent stent strut 334. A connecting portion 342 between adjacent stent struts 334 is formed at a portion where the crowns of adjacent stent struts 334 are aligned. The connecting portion 342 is preferably formed by connecting the stent struts 334 without using additional materials by welding the turns to each other, such as by resistance welding, friction welding, laser welding, or another form of welding. Alternatively, the stent struts 334 can be connected by solder, by adding a connecting element between turns, or by another mechanical method. Further, the inner stent element 104 can be formed by pre-connecting the entire stent body from a hollow tube or sheet as a single structure, such as by laser cutting or etching. Other connections or means for joining adjacent struts will be apparent to those skilled in the art and are intended to be included herein. The inner stent element 104 can be any suitable stent known in the art and can include a valve disposed therein as will be described in detail later.

  FIG. 4 illustrates an outer stent element 102 and an inner stent element 104 that are joined together at a connection 406 to form a double wall stent system 100. The inner stent element 104 is centrally located between the struts 210 and 220 of the outer stent element 102. The outer stent element 102 and the inner stent element 104 have an outermost crown 338 at the proximal and distal ends of the inner stent element 104 and an outermost crown 210 at the proximal and distal ends of the outer stent element 102. Aligned to align with the inner crowns 214, 224. The connecting portion 406 is formed at a portion where the adjacent outermost crown and innermost crown are aligned. The connecting portion 406 connects the outer stent element 102 and the inner stent element 104 without using additional material, such as by welding the turns together, such as by resistance welding, friction welding, laser welding, or another form of welding. Preferably formed. Alternatively, the outer stent element 102 and the inner stent element 104 can be connected by solder, by adding a connecting element between turns, or by another mechanical method. In the embodiment shown in FIG. 4, the inner stent element 104 includes six stent struts 334, and when the inner stent element 104 is coupled or fused to the outer stent element 102 to form the stent system 100. System 100 has a total of eight stent struts or segments.

  In another embodiment described with reference to FIGS. 5-10, the outer stent element 102 and the inner stent element 104 can be configured to include a snap fit connection or an interference fit connection therebetween. A snap-fit connection is a mechanical interlock that houses the male element of the inner stent element within the corresponding female element of the outer stent element. The snap fit male and female elements can be joined by press fit and further fused together by welding, soldering, or cold joining. The snap-fit connection ensures proper alignment of the outer and inner stent elements. In addition, the welded snap-fit bond does not increase the outer diameter of the stent system, thus minimizing the overall dimensions of the stent system and minimizing or mitigating stress compared to other welded structures.

  Referring to FIG. 5, the outer stent element 502 is configured to couple to the corresponding inner stent element by providing a female receptacle 544 in both its proximal portion 508 and distal portion 518. The female receptacle 544 is located on the innermost crowns 514, 524 of the stent struts 510, 520. As shown in FIG. 6, the inner stent element 604 is configured to couple to the outer stent element 502 by providing male tabs 646 at both its proximal end 630 and distal end 632. ing. Male tab 646 is located on outermost crown 638 of proximal stent strut 634 and outermost crown 638 of distal most stent strut 634. Male tab 646 is configured to fit within female receptacle 644 of outer stent element 502. FIG. 7 illustrates a stent system 700 comprising an outer stent element 502 and an inner stent element 604 that are coupled together by a snap fit coupling 748. Inner stent element 604 is centrally located between struts 510 and 520 of outer stent element 502. Outer stent element 502 and inner stent element 604 are aligned such that male tab 646 of inner stent element 604 is received within female receptacle 544 of outer stent element 502. The male tab 646 is press fit into the female receptacle 544 and the snap fit joint 748 is further welded, soldered, or cold bonded. Low temperature bonded snap-fit joints 748 eliminate metallurgical effects and technical problems in welding or fusion of NiTi (Nitinol) to dissimilar metals such as, for example, CoCr alloys, stainless steel, and MP35N alloys To do. In addition, cold-bonded snap-fit joints 748 include welds and welds that can affect elements formed from tissue, polymer agents, or drugs such as porcine valves and similar materials present in stent system elements. There are several manufacturing advantages such as avoiding heat induction by

  FIG. 8 illustrates an enlarged plan view of a snap fit joint 748 between the stent strut 634 of the inner stent element 604 and the stent strut 520 of the outer stent element 502. Each snap fit joint 748 includes a male element (male tab 646) extending from the outermost crown 638 of the innermost stent strut 634 of the inner stent element and a female extending into the innermost crown 524 of the stent strut 520. It is a mechanical interlock including a mold element (female-type housing portion 544). Thus, each male element is housed within a corresponding female element. In the embodiment shown in FIG. 8, the male tab 646 has an upper and lower plane and a substantially round outer perimeter that is a substantially circular recess to which the female receptacle 544 corresponds. The male and female elements of the snap fit joint 748 with attached strut portions are formed separately and require assembly. The male and female elements of the snap fit joint 748 can be joined by press fitting and can be further fused together by welding, soldering, or cold joining. The snap fit joint ensures proper alignment of the outer and inner stent elements, minimizing or mitigating stress compared to other welded structures. Illustrated is a snap fit joint 748 in which a male element (male tab 646) is disposed on the inner stent element 604 and a female element (female receptacle 544) is disposed on the outer stent element 502. One skilled in the art will appreciate that a male element can be placed on the outer stent element and a female element can be placed on the inner stent element.

  FIG. 9 is an enlarged plan view of an alternative embodiment of a snap fit joint between the inner stent element 604 and the outer stent element 902. Similar to the embodiment described above with reference to FIG. 8, a male element (male tab 646) extends from the outermost crown 638 of the distal most stent strut 634 of the inner stent element. However, in this embodiment, the female element is not a recess in the outer stent element, but an attached female receptacle 950 having a matching recess shape to receive the male tab 646. . The female receptacle 950 extends from the innermost crown 924 of the stent strut 920. Female receptacle 950 is illustrated as an “end opening” receptacle. In another embodiment (not shown), the female element is a closed receptacle in the form of a complete ring. A closed complete ring can be circular, oval, or oval.

  FIG. 10 illustrates an enlarged plan view of an alternative interference fit joint between the inner stent element 1004 and the outer stent element 1002. In this embodiment, the interference fit joint is in the male element (male tab 1046) extending from the outermost crown 1038 of the innermost stent strut 1034 of the inner stent element and in the innermost crown 1024 of the stent strut 1020. Includes a female element (female containing portion 1044). Rather than the male and female elements snap into place “snap-in” like a snap-fit joint, the male tab 1046 is slid or received within the female receptacle 1044. , Permanently fixed to the female housing 1044 by welding or other methods. The interference fit joint ensures alignment of the outer and inner stent elements, minimizing or mitigating stress compared to other welded structures.

  Double wall stent system 100 includes a contracted or compressed geometry 1152 (see FIGS. 11 and 12) and expanded or deployed geometry 1354 (FIG. 13) sufficient to deliver to the treatment site. And see FIG. FIG. 11 shows a side view of stent system 100 in a contracted or compressed geometry 1152 and FIG. 12 illustrates an end view of stent system 100 in a contracted or compressed geometry 1152. . The outer stent element 102 is crimped against the inner stent element 104 to compress the stent system 100 to a diameter D1 sufficient for delivery into a body lumen. In the contracted or compressed geometry 1152, the stent system 100 has a length L1.

  Referring now to FIGS. 13 and 14, FIG. 13 shows a side view of the stent system 100 in an expanded or expanded geometry 1354, and FIG. 14 shows an expanded or expanded geometry 1354. 1 illustrates an end view of the present stent system 100. FIG. The longitudinal band 228 extending in the longitudinal direction of the outer stent element 102 is expanded or radially expanded by the shortening dynamics of the inner stent element 104. More specifically, the inner stent element 104 is designed to have a degree of shortening that shortens the length of the inner stent element when radially expanded. As the diameter of the inner stent element 104 expands and the length decreases, the longitudinally extending connector of the outer stent element 102 bulges outward toward the vessel wall. In the expanded or deployed geometry 1354, the stent system 100 has a length L2 that is less than the length L1. In other words, as the stent system 100 expands radially, the length of the stent system 100 decreases. Because the proximal and distal ends of the straight band 228 approach each other when the inner stent element 104 is shortened, the deployed straight band 228 of the outer stent element 102 is curved radially outward into the vessel wall. Contact and help secure the stent system 100 to the treatment site. The inner stent element 104 radially expands to a diameter D2 that is greater than the diameter D1 to form a central channel lumen 1421 through the interior. The central channel lumen 3421 has a consistent predetermined dilatation diameter to maintain blood flow therethrough. For example, the consistent predetermined expansion diameter can be approximately the same as the normal diameter of the body vessel in which the stent system is implanted. In one embodiment, in the expanded or deployed geometry 1354, the diameter of the central channel lumen 1421 is about 18 mm. However, the outer surface of the inner stent element 104 has little or no contact with the vessel wall, as shown in FIGS. 13 and 14, but rather is maintained at the radial center within the outer stent element 102. The inner stent element 104 is configured to be located in the radial center or lumen of the body lumen.

  The inner stent element 104 can be expanded in several ways. In one embodiment, deployment of self-expanding stents can be facilitated by taking advantage of the shape memory properties of materials such as nickel-titanium (Nitinol). Shape memory alloys are a group of metal compositions that have the ability to return to a defined shape or size when exposed to certain heat or stress conditions. Shape memory metals generally deform at relatively low temperatures and, when exposed to relatively high temperatures, can return to a defined shape or size that the shape memory alloy has maintained prior to deformation. Thus, the stent can be inserted into the body in a deformed and small state and return to a “remembered” large shape when exposed to high temperatures, ie body temperature or heated fluid, in vivo. Thus, a self-expanding stent has two states of size or shape: a contracted or compressed geometry sufficient to deliver to the treatment site and a deployed or expanded geometry to contact the vessel wall. Can have an arrangement. The inner stent element can be formed from a thermally expandable material such as nickel-titanium (Nitinol). When placed at the treatment or deployment site, the stent system is exposed to a heat source and the inner stent element of the stent system expands by chemical reaction or thermal expansion with the material forming the stent element. The tubular body of the inner stent element opens into its thermoforming mold and becomes a shortened dimension, so that the connector extending in the longitudinal direction of the outer stent element expands and curves outward, contacts the vessel wall, To give the necessary countering power.

  In another embodiment, the inner stent element can be formed from a self-expanding spring-type material or a superelastic material such as nickel-titanium (Nitinol) and has an expanded shape relative to the delivery catheter for delivery into the blood vessel. Can be folded or crimped into a contracted or compressed geometry. When the sleeve or sheath that holds the stent system in the collapsed state is removed, the inner stent element assumes the expanded or deployed state at the treatment site within the vessel. Due to the expansion and contraction of the inner stent element, the longitudinally extending connector of the outer stent element bends outward and contacts the vessel wall.

  In another embodiment, the inner stent element can be balloon expandable so that it is crimped against a balloon dilatation catheter for delivery to the treatment site and is expanded by the radial force of the balloon. More specifically, the stent system can be folded into a contracted or compressed geometry relative to the top of a balloon, such as the type of balloon used in angioplasty. When the balloon is inflated, it physically presses the inner stent element to radially expand it. Due to the expansion and contraction of the inner stent element, the longitudinally extending connector of the outer stent element bends outward and contacts the vessel wall. The balloon is then deflated and the stent system remains in the expanded or deployed geometry. For example, FIG. 15 is an illustration of a stent delivery system 1501 according to an embodiment of the invention. Stent delivery system 1501 includes an over-the-wire catheter 1503 having a proximal shaft 1505, a guidewire shaft 1515, and a balloon 1507. Proximal shaft 1505 has a proximal end attached to hub 1509 and a distal end attached to the proximal end of balloon 1507. Guidewire shaft 1515 extends from hub 1509 through proximal shaft 1505 and balloon 1507 to the distal tip of catheter 1503. Hub 1509 includes an inflation port 1511 for attachment to a source of inflation fluid. Inflation port 1511 is in fluid communication with balloon 1507 via an inflation lumen (not shown) extending into proximal shaft 1505. In addition, the hub 1509 includes a guide wire port 1513 that communicates with a guide wire lumen (not shown) defined by a guide wire shaft 1515 for receiving a guide wire 1517 therethrough. As described herein, guidewire shaft 1515 extends the entire length of over-the-wire catheter 1503. However, as will be appreciated by those skilled in the art, the guidewire shaft 1515 may instead extend only into the distal portion of the rapid exchange catheter 1503. A double wall stent system 100 formed in accordance with an embodiment of the present invention is placed over a balloon 1507. However, those skilled in the art will appreciate that the stent system of the present invention can be adapted to any type of delivery and expansion method. In addition, those skilled in the art will appreciate that one stent element can be self-expanding and the other stent element can be balloon expandable.

  In all embodiments, the outer and inner stent elements of the double wall stent system are preferably formed from an implantable material having good mechanical strength. For example, both elements include stainless steel, cobalt-based alloys (605L, MP35N), titanium, tantalum, platinum alloys, niobium alloys, superelastic nickel-titanium alloys (Nitinol), other biocompatible metals, or polymers, etc. It can be formed from other materials. One material that is widely used for stents is stainless steel, particularly 316L stainless steel, which is highly corrosion resistant. Although not necessary, one or more stent elements can be selectively plated with platinum or other biocompatible material to improve visibility during fluoroscopy. In addition, the outer stent element and / or the inner stent element can be selectively covered with polyester or Dacron fibers.

  Any of several conventional laser cutting methods can be used to form the outer and inner stent elements into a desired shape or pattern from solid or tubing. For example, FIG. 16 illustrates a laser cut sub-element 1656 of the inner stent element 604 of FIG. Inner stent element 604 can be laser cut from MP35N tubing having an outer diameter of about 0.25 inches and a wall thickness of about 0.012 inches or any other suitable tubing. Laser cut sub-element 1656 is shown schematically as a generally circular inner stent element 604 cut and flattened out. Although the generally cylindrical stent strut 634 is shown in a flat state, those skilled in the art will appreciate that the stent strut 634 depicted in the drawings is intended for use with a cylindrical body. I understand. When laser cut from sheet material or tubing, the stent struts 634 of the inner stent element 604 can be formed connected to one another such that the element body is a unitary structure. As shown, the male tab 646 is also formed connected to the proximal and distal ends of the inner stent element 604 such that the element is a unitary structure.

  FIG. 17 illustrates a laser cut subelement 1758 of the outer stent element 502 of FIG. The outer stent element 502 can be laser cut from MP35N tubing having an outer diameter of about 0.25 inches and a wall thickness of about 0.012 inches or any other suitable tubing. Laser cut subelement 1758 is shown schematically as a generally circular outer stent element 502 is cut and flattened. Although the generally cylindrical stent struts 510, 520 are shown in a flat state, those skilled in the art intend to use the stent struts 510, 520 depicted in the drawings for the cylindrical body. I understand that When laser cutting from sheet material or tubing, the stent struts 510, 520 and the longitudinally extending linear band 528 of the outer stent element 502 may be formed connected to one another such that the element body is a unitary structure. it can. As shown, female receptacle 544 is also formed in the proximal and distal portions of outer stent element 502 such that the element is a unitary structure.

  In addition, rather than laser cutting from any suitable tubing, the outer and inner stent elements of the double wall stent system can be manufactured in any other manner apparent to those skilled in the art. For example, a stent strut can be formed by wrapping a wire or ribbon around a mandrel to form the pattern described above, and then welding or otherwise mechanically connecting its ends. The stent struts are then joined together to form an inner stent element, or are connected to a longitudinally extending connector to form an outer stent element. Alternatively, stent struts can be manufactured by machining tube or solid material into an annular band and then bending the band relative to the mandrel to form the desired pattern. The stent struts thus formed are then connected together to form an inner stent element or connected to a longitudinally extending connector to form an outer stent element. The cross-sectional shape of the completed stent system can be circular, elliptical, rectangular, hexagonal, square, or other polygonal shape, but it is now believed that circular or elliptical shape would be preferred.

  Once the outer and inner stent elements have been formed separately in one of the ways described above, these elements are joined together to form a double wall stent system. These elements can be mechanically connected to each other by welding, soldering, cold bonding, or other methods. In a manufacturing method according to an embodiment of the present invention, these elements connect the outer stent elements by expanding them to a size sufficient to allow the inner stent elements to be inserted therein. The outer stent element is then crimped or compressed against the inner stent element into a contracted or compressed geometry. Adjacent crowns between the inner and outer stent elements are mechanically connected to each other by welding, soldering, cold bonding, or other methods.

  As described above, these elements can include corresponding male and female elements that form a snap-fit or interference fit connection when assembled to a stent system. When there are snap fit or interference fit male and female elements, these elements expand the outer stent elements to connect to each other to a size sufficient to allow the inner stent elements to be inserted therein. Once the inner stent element is inserted into the outer stent element, the male element is aligned within the female element. Thus, a snap fit connection or an interference fit connection ensures proper alignment of the outer and inner stent elements. The outer stent element is then crimped or compressed against the inner stent element into a contracted or compressed geometry. The male element is then press fit into the female element. The snap-fit or interference fit connection of the male and female elements is then mechanically coupled together by welding, soldering, cold bonding, or other methods.

  Low temperature bonded snap fit joints eliminate metallurgical effects and technical problems in welding or fusing NiTi (Nitinol) to dissimilar metals such as, for example, CoCr alloys, stainless steel, and MP35N alloys. For example, the female element can be formed from NiTi (Nitinol) and the male element can be formed from dissimilar metals such as one listed above. The cold bond joint of the male and female elements begins by forming a final “developed” bond dimension at room temperature (austenite phase). In order to produce the desired bonding effect, the temperature of the female element is made sufficiently lower than its transition temperature (TT) to transform into a martensitic phase. In practice, this can be achieved by immersing the element in a liquid nitrogen bath. In this state, the hole or recess of the female element is expanded or enlarged in the radial direction by pushing the oversized taper mandrel longitudinally into the hole or recess of the female element. When continuously cooled below the transition temperature, the female element maintains stable expansion. Then, the coupling of the female element and the male element is inserted into the female element with the end of the male element expanded, and the female element is heated to approximately its original diameter, that is, the memory diameter. To achieve. The radial contraction of the female element and the associated chronic force allows the joint to continuously clamp at body temperature, ie a temperature higher than the designed transition temperature well below 37 ° C. When the female element has an “end opening” housing as in the embodiment shown in FIGS. 8-10, the wedge effect causes the male element to move from the outer diameter of the female element to the female element. Passing in the radial direction to the inner diameter of the is prevented. In another embodiment, the female element is a closed receptacle in the form of a complete ring. The ring can be circular, oval or elliptical. As the male element passes through the closed receptacle of the female element, it is clamped in the radial direction, axial direction, or a combination thereof.

  As described above, in some embodiments of the present invention, the outer stent element comprises a proximal stent strut and a distal stent strut connected to each other by a longitudinally extending connector. In another embodiment, flare stent struts can be attached to the proximal and distal ends of the outer stent element to prevent stent migration and valve leakage. More specifically, with reference to FIGS. 18A and 18B, the flow through a “straight” double wall stent system is compared to the flow through a “flared” double wall stent system. The inner stent element is represented by a tubular segment 1864 and the outer stent element is represented by an elongated oval segment 1865. FIG. 18A illustrates the flow represented by arrow 1860 through a tubular segment 1864 having a straight end. Stream 1860 is guided primarily straight into the system. However, due to the relatively small inlet of the tubular segment 1864, a portion of the flow represented by the arrow 1862 “does not enter” the inlet and bounces and flips on the side of the segment 1865 at the proximal end of the system. Similarly, the relatively small outlet of tubular segment 1864 causes a portion of the flow represented by arrow 1863 to flow back and be bounced and reversed on the side of segment 1865 at the distal end of the system. The flow 1862 results in an undesired rotational movement of the system and a phenomenon known as “watermelon seeding” that causes the system to move distally an unpredictable distance.

  In comparison, the flare end segment helps prevent such undesired movement and can be formed with an appropriate length and flare angle to prevent congestion and subsequent thrombus formation. . FIG. 18B illustrates the flow represented by arrow 1860 through a tubular segment 1864 having a flared end 1866. Due to the relatively large inlet of the flared inlet end 1866, the flow 1860 is guided straight into the system at the proximal end of the system. Similarly, the relatively large outlet at the flared outlet end 1867 guides the flow 1860 straight out of the system at the distal end of the system.

FIG. 19 shows a side view of an outer stent element 1902 having flared stent struts 1968 at the proximal and distal ends. Outer stent element 1902 has a proximal portion 1908 and a distal portion 1918. Similar to outer stent element 102, proximal portion 1908 includes a generally cylindrical stent strut 1910 and distal portion 1918 includes a generally cylindrical stent strut 1920. Stent strut 1910 at proximal portion 1908 of outer stent element 1902 is a wavy or sinusoidal cylindrical band or ring having a pattern of crown 1914 and straight segment 1919 connecting adjacent straight segments 1919, and outer stent element 1902. The stent strut 1920 at the distal portion 1918 is a wavy or sinusoidal cylindrical band or ring having a pattern of crowns 1924 and straight segments 1929 connecting adjacent straight segments 1929. Proximal stent strut 1910 and distal stent strut 1920 are aligned by _a common longitudinal axis La and are connected by a plurality of longitudinally extending connectors, such as straight band 1928. The straight band 1928 is a generally straight strip extending parallel to the common longitudinal axis La from the valley 1916 of the crown 1914 of the stent strut 1910 to the valley 1926 opposite the crown 1924 of the stent strut 1920. Or it is the material of a support plate. However, unlike the outer stent element 102, the embodiment illustrated in FIG. 19 includes flared stent struts 1968 at the proximal end 1912 and the distal end 1922 of the outer stent element 1902. Flare stent strut 1968 is coupled to the proximal stent strut 1910 and distal stent struts 1920 as a proximal end 1912 and distal end 1922 forms an angle of about 20 degrees to the longitudinal axis L _a It is flare in the radial direction. Accordingly, the outer diameter of the flared stent strut 1968 at the proximal end 1912 and the distal end 1922 is larger than the outer diameter of the proximal stent strut 1910 and the distal stent strut 1920. In addition, the straight segment of flare stent strut 1968 can be longer than the straight segments 1919, 1929 of proximal stent strut 1910 and distal stent strut 1920, and the crown of flare stent strut 1968 can be proximal stent strut 1910. And larger than each of the crowns 1914, 1924 of the distal stent strut 1920. Flared stent struts 1968 can prevent unwanted rotational rotation of the stent and watermelon seeding, and can further prevent congestion and subsequent thrombus formation. In addition, FIG. 19 is shown to be coupled to the inner stent element by placing a mounting female receptacle 1950 on both the innermost crown 1914 of the proximal stent strut 1910 and the innermost crown 1924 of the distal stent strut 1920. An outer stent element 1902 is shown.

A double wall stent system utilizing an outer stent element 1902 with a flared stent strut 1968 at the end is used with an inner stent element having four stent struts so that the stent system holds a total of eight stent struts. be able to. For example, FIG. 20 illustrates an inner stent element 2004 that can be used with an outer stent element having a flared end. Inner stent element 2004 is a cylindrical tubular body having _a longitudinal axis L _a , a proximal end 2030, and a distal end 2032. Longitudinal axis L _a extends into a cylindrical body from the proximal end 2030 of the inner stent element 2004 to the distal end 2032. Stent struts 2034 a plurality of proximity is substantially aligned parallel to the longitudinal axis L _a to form a cylindrical tubular body of the inner stent element 2004. Each stent strut 2034 is a wavy or sinusoidal cylindrical band or ring having a pattern of crowns 2038 and straight segments 2039 connecting adjacent straight segments 2039. FIG. 20 shows an inner stent element 2004 having four stent struts 2034 connected by a connecting portion 2042. In addition, FIG. 20 illustrates that the inner stent element 2004 is configured to couple to the outer stent element by placing a male tab 2046 at both the proximal end 2030 and the distal end 2032 of the inner stent element 2004. Is shown.

  In a further embodiment of the invention, the longitudinally extending connector connecting the proximal portion of the outer stent element to the distal portion of the outer stent element has several possible embodiments. As previously described, the longitudinally extending connector of the outer stent element contacts the vessel wall when deployed to help secure the stent system at the treatment site. Because the inner stent element is maintained at the radial center within the body lumen, and the longitudinally extending connector of the outer stent element is responsible for potential patient growth and / or vascular abnormalities. First, the double wall stent system is particularly suitable for the treatment of right ventricular outflow tract abnormalities because it is curved radially outward to ensure that the system is secured to the vessel wall. As already described above in connection with the embodiment of the outer stent element, the longitudinally extending connector comprises a generally straight band material extending from the proximal end to the distal end of the outer stent element. can do. In a further embodiment of the invention described in detail below, the longitudinally extending connector of the outer stent element is a plurality of longitudinal and radial foldable wavy or sinusoidal bands or spars. Adjacent longitudinally extending connector sinusoidal bands or spars can be nested together. The longitudinally extending connector extends generally parallel to the longitudinal axis of the outer stent element, but extends at an angle, i.e., at an angle, to the longitudinal axis of the outer stent element. Or it may extend helically around the longitudinal axis of the outer stent element.

For example, FIG. 21 shows a side view of an outer stent element 2102 with a longitudinally extending connector according to another embodiment of the present invention. In this embodiment, the connector extending in the longitudinal direction is a connector band 2170. Connector band 2170 includes a straight proximal portion 2172, a wavy or sinusoidal intermediate portion 2174, and a straight distal portion 2176. The wavy or sinusoidal intermediate portion 2174 provides both additional surface area and pockets that allow tissue growth to further assist in anchoring the stent system to the vessel wall and prevent migration of the stent after deployment. Connector band 2170 extends to the valley portions 2126 on the opposite side of the crown 2124 of the stent struts 2120 from the valley portions 2116 of the crown 2114 of the stent struts 2110 generally parallel to the common longitudinal axis L _a. The straight proximal portion 2172 and the straight distal portion 2176 have a length approximately equal to the length of the straight segments of the stent struts 2110, 2120, while the sinusoidal intermediate portion 2174 spans the entire length of the inner stent element when assembled. And has a length that is approximately equal to the length of the inner stent element. Although the embodiment shown in FIG. 21 includes a flared stent segment 1968 at the proximal end 2112 and distal end 2122 of the outer stent element 2102, the connector band 2170 is the outer disclosed herein. It should be understood that any embodiment of the stent element can be used as a longitudinally extending connector.

  FIG. 22 shows a side view of an expanded or deployed geometry double wall stent system 2200, and FIG. 23 illustrates an end view of the expanded or deployed geometry stent system 2200. Yes. Stent system 2200 includes an outer stent element 2102 (of FIG. 21) and an inner stent element 2004 (FIG. 20) coupled to the outer stent element 2102. Outer stent element 2102 includes a corrugated connector band 2170 that is deployed to help secure the stent system to the treatment site. The inner stent element 2004 defining the central flow path lumen 2321 is shown in a geometrical configuration expanded or deployed at the radial center within the outer stent element 2102. The embodiment shown in FIGS. 22 and 23 comprises an inner stent element having four stent struts, which may be any desired depending on the desired overall length and / or the desired mechanical properties of the system. It should be understood that a number of stent struts can be provided.

In FIGS. 22 and 23, similar to the other embodiments already described, the longitudinally extending connector is a trough and trough connector, i.e., from the trough of the proximal stent strut to the trough of the distal stent strut. It is a connector extending to the part. However, the longitudinally extending connector may be a “crown to crown” connector extending from the crown of the proximal stent strut to the crown of the distal stent strut. For example, FIG. 24 shows a side view of a deployed or expanded geometric double wall stent system 2400 according to another embodiment of the present invention. Stent system 2400 includes an outer stent element 2402 coupled to inner stent element 104. Outer stent element 2402 has a proximal portion 2408 and a distal portion 2418. Proximal portion 2408 includes two connected generally cylindrical stent struts 2410 and distal portion 2418 includes two connected generally cylindrical stent struts 2420. Although shown as two connected stent struts in the proximal and distal portions, it should be understood that the proximal and distal portions of the outer stent element can comprise any number of stent struts. . The stent strut 2410 of the proximal portion 2408 of the outer stent element 2402 is a wavy or sinusoidal cylindrical band or ring having a pattern of crowns 2414 and straight segments 2419 connecting adjacent straight segments 2419, and the outer stent elements 2402. The stent strut 2420 of the distal portion 2418 is a wavy or sinusoidal cylindrical band or ring having a pattern of crowns 2424 and straight segments 2429 connecting adjacent straight segments 2429. The proximal stent struts 2410 and a distal stent struts 2420, common aligned to the longitudinal axis L _a, longitudinal axis proximal end 2412 and distal end 2422 of the common outer stent element 2402 L _a Is flared in the radial direction so as to form an angle of about 20 degrees with respect to the angle. Accordingly, the outer diameter of the flared stent struts 2410, 2420 at the proximal end 2412 and the distal end 2422 is larger than the outer diameter of the inner stent element 104. Flared stent struts 2410, 2420 can prevent unwanted stent rotational movement and watermelon seeding, and can further prevent congestion and subsequent thrombus formation.

  The flare stent struts 2410, 2420 are connected by a plurality of longitudinally extending connectors that extend parallel to a common longitudinal axis La. The longitudinally extending connector of the outer stent element 2402 includes a plurality of wavy or sinusoidal bands 2478 extending from the innermost crown 2414 of the proximal stent strut 2410 to the innermost crown 2424 opposite the distal stent strut 2420. It is. The wavy or sinusoidal intermediate band 2478 provides both additional surface area and pockets that allow tissue growth to further assist in securing the stent system to the vessel wall and prevent migration of the stent after deployment. Similar to the crown and crown connector, the sinusoidal band 2478 has a length approximately equal to the length of the inner stent element 104 so that the inner stent element 104 can be positioned between the stent struts 2410 and 2420. The sinusoidal bands 2478 can be nested within each other when not expanded (not shown), as will be described below using the embodiment of FIG. In addition, the stent system 2400 illustrates a valve 2436 in the inner stent element 104 that controls the flow therethrough. The valve 2436 may be a bovine or porcine valve that has been processed and prepared for human use, or it may be a mechanical valve or an artificial leaflet valve. If the valve is utilized within an inner stent element, the inner stent element must function as a blood flow conduit that guides blood flow through the center of the device and blocks blood flow from the outer wall of the stent system. is there. A valve may be used with the graft to function as a blood flow conduit, or a bovine or porcine valve may be retained in the natural conduit. The stent system 2400 also illustrates a graft material 2440 that surrounds the proximal stent struts 2410 of the outer stent element 2402 and the inner surface of the inner stent element 104. The valve 2436 can be hermetically sealed and permanently attached to the graft material 2440 and / or the inner stent element 104. The graft material 2440 can be a low porosity fabric such as polyester, Dacron fiber, or PTFE that forms a unidirectional flow path when attached to the inner stent element 104.

  In another embodiment of the invention, the outer stent element can comprise one or more transverse connectors for attaching adjacent longitudinally extending connectors. The use of a lateral connector aims to stabilize the longitudinally extending connectors laterally by preventing the longitudinally extending connectors from being folded together by the force applied by the vessel wall. In addition, the lateral connector provides the advantage of additional scaffolding or support and additional fixation to the vessel wall. In one embodiment of the present invention, the lateral connector can simply be a tether that connects the longitudinally extending connectors together. For example, FIG. 37 shows the outer stent element 2102 already described with reference to FIG. 21 having a tether 3785 that functions as an intermediate connector between the corrugated connector bands 2170 of the outer stent element 2102. FIG. 37 shows a tether 3785 in a folded or unexpanded geometry having a U or V shape. FIG. 38 shows an expanded or deployed geometry double wall in which the tether 3785 is radially expanded and stretched to form a straight structure between adjacent wave connector bands 2170 of the outer stent element 2102. The stent system 2200 is illustrated. The deployed stent system 2200 includes an outer stent element 2102 of FIG. 20 and an inner stent element 2004 of FIG. 20 coupled to the outer stent element 2102. Inner stent element 2004 is shown in a geometrical configuration expanded or deployed in the radial center within outer stent element 2102. While FIGS. 37 and 38 illustrate only one lateral connector that connects adjacent longitudinally extending connectors, in various other embodiments, multiple connectors are used to provide multiple pairs of proximity. A connector extending in the longitudinal direction may be connected.

In another embodiment of the present invention, an intermediate stent strut is disposed between the proximal and distal stent struts and a longitudinally extending connector connects the proximal stent strut to the intermediate stent strut. In addition, an intermediate stent strut is connected to the distal stent strut. For example, FIG. 25 shows a side view of the outer stent element 2502. In this embodiment, in addition to the proximal and distal portion stent struts 2510, 2520, the outer stent element 2502 also includes an intermediate stent strut 2586. Intermediate stent struts 2586 is a wavy or sinusoidal cylindrical band or ring having a pattern of straight segments and a crown 2588 which connects the straight segment adjacent, substantially to the longitudinal axis L _a stent strut 2510, 2520 Aligned in parallel. In one embodiment, the intermediate stent strut 2586 has a total of 16 crowns, that is, twice as many crowns as the stent struts 2510, 2520 of the proximal and distal portions, respectively. A longitudinally extending connector connects proximal stent strut 2510 to intermediate stent strut 2586 and further connects intermediate stent strut 2586 to distal stent strut 2520. In the embodiment of FIG. 25, the longitudinally extending connectors are such that one set of connectors connects the proximal stent strut 2510 to the intermediate stent strut 2586 and the other set of connectors connects the distal stent strut 2520 to the intermediate stent. There are two sets of connector bands 2580 to connect to the struts 2586.

Each connector band 2580 includes a straight portion 2582 and a wavy or sinusoidal portion 2584. The wavy or sinusoidal portion 2584 provides both additional surface area and pockets that allow tissue growth to further assist in securing the stent system to the vessel wall and prevent migration of the stent after deployment. Connector band 2580 extends from the valley portion 2516/2526 of the stent struts 2510/2520 generally parallel to the common longitudinal axis L _a to the opposite side of the crown 2588 of the intermediate stent strut 2586. The straight portion 2582 has a length approximately equal to the length of the straight segments of the stent struts 2510, 2520, and the sinusoidal portion 2584 has a length sufficient to reach the opposite crown of the intermediate stent strut 2586. . Although the embodiment shown in FIG. 25 includes flared stent segments 1968 at the proximal end 2512 and the distal end 2522 of the outer stent element 2502, the connector band 2580 is the outer disclosed herein. It should be understood that any embodiment of the stent element can be used as a longitudinally extending connector.

  26 shows a side view of the expanded or deployed geometric double wall stent system 2600, and FIG. 27 shows an end view of the expanded or deployed geometric double wall stent system 2600. Illustrated. The stent system 2600 includes an outer stent element 2502 (of FIG. 25) and an inner stent element 2004 (of FIG. 20) coupled to the outer stent element 2502. Outer stent element 2502 includes an intermediate stent strut 2586 and two sets of connector bands 2580 arranged to help secure the stent system to the treatment site. The intermediate stent strut 2586 has an expanded diameter that, when expanded, is sufficient to contact the vessel wall while allowing proper placement of the inner stent element 2004 at the center of the lumen within the vessel. The addition of an intermediate stent strut 2586 allows further support for the vessel wall. The inner stent element 2004 defining the central flow channel lumen 2721 is shown in a geometrical configuration expanded or deployed at the radial center within the outer stent element 2502. The embodiment shown in FIGS. 26 and 27 includes an inner stent element having four stent struts, which may be any desired depending on the desired overall length and / or desired mechanical properties of the system. It should be understood that a number of stent struts can be provided.

  FIG. 28 is a laser cut sub-element for forming an outer stent element according to another embodiment of the present invention. Although the laser cut subelement is shown schematically as a flattened, generally circular outer stent element 2802, those skilled in the art will use the subelement disclosed herein as a cylinder. It is understood that this is intended. In the present embodiment, the connector extending in the longitudinal direction is a spiral spar 2890 that is nested in each other. More specifically, the helical spar 2890 includes a straight proximal portion 2872, a wavy or sinusoidal intermediate portion 2874, and a straight distal portion 2876. The wavy or sinusoidal intermediate portion 2874 provides both additional surface area and pockets that allow tissue growth to further aid anchoring of the stent system to the vessel wall and prevent migration of the stent after deployment. The sinusoidal middle portion 2874 has a pattern of crowns 2892 and straight segments connecting adjacent straight segments. The valley portion 2894 is an open curved portion formed by the crown 2892, that is, a hollowed portion. Every other crown 2892 of the helical spar 2890 is nested within a corresponding valley 2894 of the adjacent helical spar 2890. The straight proximal portion 2872 and the straight distal portion 2876 have a length approximately equal to the length of the straight segments of the stent struts 2810, 2820, while the sinusoidal intermediate portion 2874 causes the proximal stent strut 2810 to be the distal stent strut. It is at least long enough to connect to 2820. Although the embodiment shown in FIG. 28 includes flared stent segments 1968 at the proximal end 2812 and distal end 2822 of the outer stent element 2802, the helical spar 2890 is the outer disclosed herein. It should be understood that any embodiment of the stent element can be used as a longitudinally extending connector.

29 is a laser cut sub-element for forming an outer stent element according to another embodiment of the present invention, and FIG. 30 is a side view of an outer stent element formed based on the laser cut sub-element of FIG. It is. Although the laser cut sub-element is shown schematically as a flattened, generally circular outer stent element 2902, those skilled in the art will use the sub-element disclosed herein as a cylinder. It is understood that this is intended. Similar to the embodiment of FIG. 28, the longitudinally extending connector has every other crown of the first helical spar nested within a corresponding valley of the second adjacent helical spar. In this respect, the spiral spars 2990 are nested in each other. However, in the embodiment of FIG. 29, two nested helical spar 2990 extend between the crown 2914 of the proximal stent strut 2910 and the crown 2924 of the distal stent strut 2920. Accordingly, the outer stent element 2990 is provided with a connector extending in the longitudinal direction twice as long as the outer stent element shown in the previous embodiment. For example, in the embodiment shown in FIG. 29, a total of 16 helical spar 2990 is provided between the proximal stent strut 2910 and the distal stent strut 2920. The increase in the number of longitudinally extending connectors helps secure the stent system to the vessel wall and further provides additional support in the radial direction of the vessel. As shown in Figure 30, the helical spur 2990, although not extend generally parallel to the longitudinal axis L _a of the outer stent element, a spiral around the longitudinal axis L _a and the inner stent element Cover or roll over formula. The spiral method used herein, the connector extending from the proximal end of the stent system at an angle greater than 0 with respect to the longitudinal axis L _a longitudinally extending into the distal end of the stent system Is intended to be defined. This predetermined angle of the helix reduces the extent to which the longitudinally extending connector bulges / curves outward when the inner stent element is expanded and shortened. Swelling toward the outside of the longitudinally extending connector can be achieved by providing a wavy or sinusoidal portion along the length of the longitudinally extending connector. The wavy or sinusoidal portion can be cut long and compressed prior to delivery so that the longitudinally extending connector can compensate for any loss of benefit due to reduced shortening of the inner stent element. In addition, the wavy or sinusoidal portion provides both additional surface area and pockets that allow tissue growth to further assist in securing the stent system to the vessel wall and prevent migration of the stent after deployment. The embodiment shown in FIGS. 29 and 30 includes a flared stent segment 1968 at the proximal end 2912 and the distal end 2922 of the outer stent element 2902, although the helical spar 2990 is described herein. It should be understood that any embodiment of the disclosed outer stent element can be used as a longitudinally extending connector.

  FIG. 31 is a laser cut sub-element for forming an outer stent element according to another embodiment of the present invention. Although the laser cut subelement is shown schematically as a flattened, generally circular outer stent element 3102, those skilled in the art will use the subelement disclosed herein as a cylinder. It is understood that this is intended. In this embodiment, the longitudinally extending connectors are spar 3196 aligned with each other. More specifically, spar 3196 includes alternating straight portions 3198 and wavy or sinusoidal portions 3199. The sinusoidal portion 3199 of the first spar 3196 abuts the straight portion 3198 of the second adjacent spar 3196. Similar to the embodiment of FIGS. 29 and 30, to increase the number of longitudinally extending connectors provided on the outer stent element, two spar 3196 are provided to connect the crown 3114 and distal of the proximal stent strut 3110. The stent strut 3120 extends between the crown 3124. For example, in the embodiment shown in FIG. 31, a total of 16 helical spar 3196 is provided between the proximal stent strut 3110 and the distal stent strut 3120. The increase in the number of longitudinally extending connectors helps secure the stent system to the vessel wall and further provides additional support in the radial direction of the vessel. Although the embodiment shown in FIG. 31 includes flared stent segments 1968 at the proximal end 3112 and distal end 3122 of the outer stent element 3102, the spar 3196 is an outer stent as disclosed herein. It should be understood that any embodiment of the element can be used as a longitudinally extending connector.

  In the previously described embodiments, the outer stent element is attached to the inner stent element. In other embodiments of the invention, the outer stent element can be loosely captured or retained by the inner stent element such that the outer and inner stent elements are “floating”. In such a “floating” embodiment, the longitudinally extending connector of the outer stent element is threaded through a hook attached to the outer surface of the inner stent element or the outermost stent adjacent to the inner stent element. Can pass through openings between struts. The floating connection between the outer stent element and the inner stent element provides more flexibility due to the conformity of the shape of the entire stent system than the fixed or anchored connection. In addition, the floating connection provides a greater degree of mechanical separation between the inner wall of the stent system defined by the inner stent element and the outer wall of the stent system defined by the outer stent element than the previously described embodiments. Enlarge. Mechanical separation allows the placement of a secondary device having a constant diameter, such as a valve, to allow placement of a secondary device having a constant diameter within a relatively large size and / or irregularly shaped blood vessel. It is important for a stent system that is retained within the central channel lumen of the system. The outer stent element provides a force against the required vessel wall but minimizes mechanical effects on the inner stent element, so that the shape of the central flow channel lumen of the stent system defined in the inner stent element or The possibility of changing size is reduced. In addition, the floating connection minimizes the stress point between the outer stent element and the inner stent element, thereby extending the life of the device. The floating connection may be located at both the proximal and distal ends of the stent system, or may be utilized at only one end of the stent system, eg, a fixed connection obtained by welding or the like. The portion may be provided at the other end of the stent system. In another embodiment, the floating connection and the fixed connection may be different for each band.

  For example, FIGS. 39 and 39A illustrate a “floating” or sliding connection 3933 between an outer stent element 3902 and an inner stent element 3904 of a double wall stent system 3900 according to another embodiment of the present invention. ing. A plurality of longitudinally extending bands or spar 3928 of the outer stent element 3902 are loosely captured or held in place by the inner stent element 3904 so that the inner stent element 3904 is independent of the outer stent element. It is possible to float. Similar to the previous embodiment, the outer surface of the longitudinally extending band or spar 3928 of the outer stent element 3902 defines the outer diameter of the stent system 3900, and the cylindrical tubular body of the inner stent element 3904 is the stent system 3900. A central flow path lumen 3921 having an inner diameter of The central channel lumen 3921 has a consistent predetermined dilatation diameter to maintain blood flow therethrough. For example, the consistent predetermined expansion diameter can be approximately the same as the normal diameter of the body vessel in which the stent system is implanted. The inner stent element 3904 may employ any suitable stent structure known to those skilled in the art and may include a valve disposed therein.

  Inner stent element 3904 has a proximal end 3930 and a distal end 3932, each of which may include a plurality of hooks or loops 3931 on the outer periphery. Each hook or loop 3931 is a lace or band material having a first end and a second end, the first end and the second end being connected to the outer surface of the inner stent element 3904. To define a receiving portion. Alternatively, a single filament can be knitted continuously around the outer periphery of the inner stent element to form a plurality of hooks or loops. Each band 3928 of the outer stent element 3902 is a slightly curved strip or support plate material that acts like a leaf spring when expanded. In this embodiment, the band 3928 is longer than the tubular body length of the inner stent element 3904. Each band 3928 is individually encased in a receptacle defined by a corresponding set of hooks or loops 3931 on the inner stent element 3904, one disposed at the proximal end 3930 and the other disposed at the distal end 3932. “Threaded” or placed. In this manner, the proximal end of each band 3928 extends proximally of the proximal end 3930 of the inner stent element 3904, and the distal end of each band 3928 is the distal end of the inner stent element 3904. 3932 extends distally. The end of each band 3928 is radially outward such that the band 3928 has a sinusoidal shape to capture or maintain the outer stent element 3902 within a plurality of hooks or loops 3931 during advancement and search for the treatment site. It is slightly curved toward Bands 3928 are defined by resizing the bands such that a portion of each band has a width that is too large to pass through the receptacle defined by hooks or loops 3931 or by hooks or loops 3931. Individually by changing the shape of the band so that each band part has a zigzag or other shape that is difficult or unlikely to pass through the receptacle, or to stabilize the band against the inner stent element Additional or otherwise retained in multiple hooks or loops 3931 by the addition of a separate fabric or other substrate knitted continuously around the outer periphery of the inner stent element 3904 across the gap between the bands 3928 Can do. The inner stent element 3904 is located in the center or inside the band 3928 of the outer stent element 3902 but is not secured to the outer stent element 3902. Rather, the floating connection 3933 is disposed between the two elements and the band 3928 of the outer stent element 3902 is disposed around the outer periphery of the proximal end 3930 and the distal end 3932 of the inner stent element 3904. A plurality of hooks or loops 3931 are loosely captured or held in place. Thus, the inner stent element 3904 can “float” or move independently of the outer stent element 3902.

  In the previously described embodiments in which the outer stent element is secured to the inner stent element, the outer stent element is deployed or radially expanded due to the shortening dynamics of the inner stent element. However, in the “floating” configuration, the longitudinally extending band 3928 of the outer stent element 3902 self-expands and curves radially outward and contacts the vessel wall to the treatment site of the stent system 3900. Help fix. For example, in one embodiment, deployment of a self-expanding outer stent element 3902 can be facilitated by utilizing the shape memory properties of a material such as nickel-titanium (Nitinol). Shape memory metals are a group of metal compositions that have the ability to return to a defined shape or size upon exposure to specific temperature or stress conditions. Shape memory metals can generally be deformed at relatively low temperatures, and when exposed to relatively high temperatures, they return to the defined shape or size they had prior to deformation. Thus, when the stent element is exposed to a high temperature in vivo, i.e. body temperature or heated fluid, the stent element is placed in the body in a deformed linear state so that it returns to its "memory" curve shape. Can be inserted. When placed at the treatment or deployment site, the longitudinally extending band 3928 of the outer stent element 3902 is in the form of a heated shape that contacts the vessel wall and provides the necessary opposing forces on the vessel.

  In another embodiment, deployment of the self-expanding outer stent element 3902 can be facilitated by utilizing a self-expanding spring-loaded or superelastic material such as nickel-titanium (Nitinol). The self-expanding outer stent element 3902 can be folded or crimped into a contracted or compressed geometry from an expanded shape for a delivery catheter for delivery into a blood vessel. When the sleeve or sheath that holds the stent system in the collapsed shape is removed, the outer stent element 3902 assumes an expanded or deployed state at the treatment site within the vessel. The inner stent element 3904 can be balloon expandable or self-expandable. In the previous embodiment, the outer surface of the inner stent element 3904 makes little or no contact with the vessel wall, but rather remains centrally within the outer stent element 3902. The inner stent element 3904 is configured such that the central channel lumen 3921 is located at the radial center in the blood vessel.

  In another “floating” embodiment of the present invention, the longitudinally extending connector of the outer stent element can be threaded through an opening between the outermost stent struts of the inner stent element. For example, FIGS. 40 and 40A illustrate a “floating” or sliding connection 4033 between the outer stent element 4002 and the inner stent element 4004. Similar to the above embodiment, the longitudinally extending band or spar 4028 of the outer stent element 4002 defines the outer diameter of the stent system 4000. Any suitable stent structure known to those skilled in the art can be employed, and the inner stent element 4004, which can include a valve disposed therein, defines a central flow lumen 4021 of the stent system 4000. . A plurality of adjacent stent struts 4034 are aligned to form the cylindrical tubular shape of the inner stent element 4004. A plurality of longitudinally extending bands or spar 4028 of the outer stent element 4002 are threaded through openings between adjacent stent struts 4034 to form a floating connection 4033. More specifically, the proximal portion of each band 4028 is threaded through an opening between adjacent stent struts 4034 at the proximal end of the inner stent element 4004 and the distal portion of each band 4028 is passed through the inner stent element 4004. Are passed through openings between adjacent stent struts 4034 at the distal end of each. The end of the band 4028 has a sinusoidal shape for the band 4028 to capture or maintain the outer stent element 4002 within the opening defined by the adjacent stent struts of the inner stent element 4004 during advancement and search with respect to the treatment site. As shown, it is slightly curved outward in the radial direction. In addition, a separate fabric or other substrate can be knitted continuously around the outer periphery of the inner stent element 4004 across the gap between the individual bands 4028 to stabilize the band against the inner stent element. . Band 4028 of outer stent element 4002 is self-expanding like band 3928 described above.

It should be understood that in any embodiment of the present invention, the inner stent element can be internally provided with a valve that controls the flow therethrough. FIG. 32 shows an inner stent element 3204 with a valve 3236 therein that can block unidirectional flow. As described in the previous embodiment of the inner stent element, inner stent element 3204 is substantially parallel to the aligned plurality of adjacent stent to form a cylindrical tubular body with respect to the longitudinal axis L _a A strut 3234 is provided. In addition, the inner stent element 3204 includes a valve 3236 hermetically and permanently attached to its inner surface and / or graft material 3240 surrounding or lining a plurality of stent struts 3234 of the inner stent element 3204. The valve 3236 may be a bovine or porcine valve that has been processed and prepared for human use, or it may be a mechanical valve or a prosthetic leaflet valve. The graft material 3240 can be a low porosity fabric such as polyester, Dacron fiber, or PTFE that forms a unidirectional flow path when attached to the inner stent element 3204. For example, an inner stent element may be used in humans as disclosed in US Pat. No. 5,957,949 entitled “Percutaneous Placement Valve Stent” by Leonhardt et al., The disclosure of which is incorporated herein by reference. It can consist of a percutaneously implanted bovine or porcine valve that has been treated and prepared for use and sewn into a laser welded stent. The double wall stent system of the present invention is particularly suitable for use in the right ventricular outflow tract because the outer stent element allows patient growth and / or regulates body lumen abnormalities as described above. ing. Thus, it may be desirable to utilize a stent-valve as an inner stent element when treating a right ventricular outflow tract abnormality. However, the double wall stent system of the present invention can also be utilized without an internal valve for the treatment of any other condition for which the stent system is deemed useful. Regardless of the specific structure of the inner stent element, the outer stent element is curved radially outward to accommodate the growth and / or abnormalities of the body lumen, thereby creating a double wall stent system for the body lumen. It works to fix in place. Thus, the inner stent element can be any suitable stent known to those skilled in the art provided it is configured to connect to the outer stent element.

  Although various embodiments according to the present invention have been described above, it should be understood that these embodiments are presented by way of example only and not limitation. It will be apparent to those skilled in the art that various modifications, in form and detail, are possible within the scope of the invention without departing from the spirit and scope of the invention. Accordingly, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the appended claims and their equivalents. It is also to be understood that each embodiment described herein and each feature of each reference mentioned herein can be used in combination with the features of any other embodiment. All patents and publications mentioned herein are hereby incorporated by reference in their entirety.

Claims (13)

A stent system for use in a body lumen comprising:
An inner stent element having a generally tubular cylindrical body defining a proximal end, a distal end, and a central channel lumen therethrough;
An outer stent element having a plurality of longitudinally extending connectors radially disposed about the tubular cylindrical body of the inner stent element;
Means for attaching the outer stent element to the inner stent element slidably rather than anchoring;
When the stent system has a radially expanded geometry, the longitudinally extending connector of the outer stent element is radially outward with respect to the vessel wall of the body lumen. The inner stent element is radially located within the longitudinally extending connector of the outer stent element,
A stent system characterized by the above. The means for attaching comprises at least one hook disposed on an outer surface of the inner stent element, the hook defining a receiving portion for receiving a longitudinally extending connector;
The stent system according to claim 1. The at least one hook includes a lace material having a first end and a second end, the first end and the second end being coupled to the inner stent element and the Defining the containment part,
The stent system according to claim 2. A filament is knitted around the outer periphery of the inner stent element to define a plurality of hooks;
The stent system according to claim 2. The means for attaching includes a portion of each longitudinally extending connector threaded through an opening in the inner stent element;
The stent system according to claim 1. The inner stent element comprises a plurality of adjacent stent struts aligned to form a tubular cylinder thereof, and a proximal portion of the longitudinally extending connector is provided near the inner stent element. A distal portion of the longitudinally extending connector is passed through the openings between the plurality of adjacent stent struts at the distal end and the plurality of adjacent stents at the distal end of the inner stent element Passed through the opening between the struts,
The stent system according to claim 5. A proximal end of each longitudinally extending connector extends proximally of a proximal end of the inner stent element, and a distal end of each longitudinally extending connector is the inner Extending distally of the distal end of the stent element,
The stent system according to claim 1. The inner stent element is centrally located longitudinally between the proximal and distal ends of the longitudinally extending connector;
The stent system according to claim 7. The connector extending in each longitudinal direction is a band having a first end and a second end, and the first end and the second end of the band are radially outward. Slightly curved,
The stent system according to claim 1. The longitudinally extending connector is self-expanding,
The stent system according to claim 1. In the radially expanded geometry, the longitudinally extending connector of the outer stent element causes the inner stent element to make little or no contact with the wall of the body lumen. Radially expanded larger than the stent element,
The stent system according to claim 1. The longitudinally extending connector extends generally parallel to a longitudinal axis of the outer stent element;
The stent system according to claim 1. A valve disposed within the central channel lumen of the inner stent element, further comprising a non-porous graft material covering at least a portion of the inner stent element;
The stent system according to claim 1.

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