EA040514B1 - GROWING STENT AND VALVE FOR CONGENITAL CONSTRAINTS - Google Patents

Description

Cross-reference to related applications

The present application claims priority under United States Patent Application No. 16/441,201, filed June 14, 2019, which claims priority under United States Provisional Application No. hereby incorporated in this application by reference for all purposes.

The technical field to which the invention belongs

The disclosed embodiments relate to medical stents, and more specifically, but not exclusively, to growing a stent for implantation in young patients and then expanding to adult size vessels as the patient grows while maintaining adequate strength to open the vessel throughout the range of expansion.

Background Art Information

Stents have been used for many years to treat vascular disease by providing adequate blood flow and/or preventing vasoconstriction. Vasoconstriction impairs blood flow and can create a pressure imbalance in the vasculature. Such conditions can eventually lead to serious cardiovascular disease and/or death. For many years, the definitive treatment for such diseases has been surgical repair or replacement of a vessel segment with open-heart surgery, but such surgeries are dangerous and prone to complications. Open-heart surgery in neonates and young patients may have negative developmental consequences.

Stents have also been used to keep vessels open, but the height of the patient precludes implantation of stents in the early stages of development as they cannot grow to adult size. Typically, stents have characteristic limited operating ranges.

In view of the foregoing, there is a need for an improved stent for implantation in young patients and subsequent expansion as patients grow, which overcomes the aforementioned problems and disadvantages of currently available stents.

The essence of the invention

The present invention relates to a growing stent for implantation in young patients and to methods of making and using the same. The growing stent can subsequently be expanded to the size of an adult vessel as the patient grows, while maintaining the necessary strength to open the vessels throughout the range of expansion. In accordance with the first aspect disclosed in this application, there is provided an expanding stent for implantation in a patient, comprising an elongated stent scaffold that is expandable from its original state to facilitate insertion into a selected patient lumen to a first expanded state to maintain the selected lumen upon implantation, wherein the scaffold The stent in the first expanded state defines an internal channel, wherein the stent frame is configured to subsequently expand from the first expanded state to the second expanded state as the patient grows.

In some embodiments of the disclosed growing stent according to the first aspect, the stent scaffold in the second expanded state may continue to support the selected lumen. The stent frame in the first expanded state may define an internal channel with a first cross section. Additionally and/or alternatively, the stent frame in the second expanded state defines an internal channel with a second cross section larger than the first cross section.

In some embodiments of the disclosed growing stent according to the first aspect, the stent scaffold may initially have a small implant size to facilitate insertion into a neonatal patient. Optionally, the implantation size can be less than 8 French and/or the first cross section can be less than 10 mm.

In some embodiments of the disclosed growing stent according to the first aspect, the stent scaffold can be expanded to a second expanded state in a child (childhood) patient. The second cross section, for example, may be between 10 and 15 mm inclusive.

In some embodiments of the disclosed growing stent according to the first aspect, the stent frame can be configured to further expand from the second expanded state to the third expanded state as the patient grows. The stent frame in the third expanded state, for example, may continue to support the selected lumen. The stent frame can optionally be configured to expand to a third expanded state in an adult patient. The stent frame in the third expanded state may define an internal channel with a third cross section larger than the second cross section. In some embodiments, the implementation of the third cross section may be from 18 to 24 mm, inclusive.

In some embodiments of the disclosed growing stent according to the first aspect, the stent frame may comprise first and second frame elements with respective arcuate elements, each of which defines a central recess. The arcuate elements may contain interacting arcuate elements. The arcuate members, for example, may converge to form a central channel as the stent frame expands from the initial state to the first expanded state. The central channel may include the intersection of the central recess of the arcuate element of the first bobbin element and the central recess of the arcuate element of the second bobbin element. Predominantly arcuate elements can provide flexibility for the frame of the stent.

In some embodiments of the disclosed growing stent according to the first aspect, the stent frame is tubular in shape. Additionally and/or alternatively, the disclosed growing stent according to the first aspect may further comprise one or more leaflets extending from the stent frame into the internal canal and providing valvular function in the first and second expanded states in selected embodiments.

In some embodiments of the disclosed growing stent according to the first aspect, the stent scaffold may comprise a predetermined number of scaffold cells and a plurality of scaffold struts, wherein the connection of the struts between the selected scaffold struts has a connection width that is small enough to facilitate insertion of said stent scaffold in the initial state and that is large enough to maintain the expansion of the specified frame of the stent to the first and second expanded states while maintaining strength to maintain the selected lumen.

In some embodiments of the disclosed growing stent according to the first aspect, the internal channel may extend between opposite end regions of the stent body, wherein at least one of the end regions is flared radially outward to facilitate engagement between said stent body and the selected lumen.

In some embodiments of the disclosed growing stent according to the first aspect, the internal channel may extend between opposite end regions of the stent frame, with at least one of the end regions radially inwardly broadened or blunted to reduce the risk of aneurysm in the selected lumen.

In some embodiments, the disclosed growing stent according to the first aspect may further comprise a fluid-impervious coating located on at least a portion of the stent frame to prevent leakage due to ingrowth of the selected lumen as the patient grows.

In some embodiments of the disclosed growing stent according to the first aspect, the stent frame is configured to be delivered to a selected lumen via a first catheter delivery system. The stent frame is optionally configured to subsequently expand to a second expanded state via a first catheter delivery system and/or subsequently expand to a second expanded state via a second catheter delivery system.

In accordance with the second aspect disclosed in this application, a catheter system is provided, containing means for implanting a growing stent in each embodiment of the first aspect.

In accordance with the third aspect disclosed in this application, a catheter system is provided, containing means for expanding a growing stent in each embodiment of the first aspect. Means for expanding, for example, may include first means for expanding the growing stent from the initial state to the first expanded state and/or second means for expanding the growing stent from the first expanded state to the second expanded state.

In accordance with the fourth aspect disclosed in this application, there is provided an expanding stent for implantation in a neonatal patient, which may include an elongated stent frame that is expandable from its original state to facilitate insertion into a selected lumen of a newborn patient to a first expanded state to maintain the selected lumen at implantation, wherein the stent frame in the first expanded state defines an internal channel with a first cross section, wherein the stent frame is configured to subsequently expand from the first expanded state to the second expanded state as the patient grows to an adolescent patient, the stent frame in the second expanded state continues maintain the selected lumen and defines an internal channel with a second cross section larger than the first cross section, and/or wherein the stent frame is made with the possibility of further expansion from the second expanded from a state to a third expanded state as the adolescent patient further grows into an adult patient, wherein the stent scaffold in the third expanded state continues to support the selected lumen and defines an internal channel with a third cross section larger than the second cross section.

In some embodiments of the disclosed growing stent in the fourth aspect, the stent frame in the initial state may have an implantation size of less than 8 French, and the first cross section may be less than 8 mm, the second cross section may be mm and/or the third cross section may be greater 20 mm.

List of figures

In FIG. 1A is an exemplary detailed diagram illustrating an exemplary embodiment of a growing stent in a first expanded state.

In FIG. 1B is an exemplary detailed diagram illustrating an alternative embodiment of the growing stent of FIG. 1A, with the growing stent shown in a second expanded state.

In FIG. 2A is an exemplary detailed diagram illustrating an embodiment of the growing stent of FIG. 1A and 1B, with the growing stent shown in the initial state for implantation.

In FIG. 2B is an exemplary detailed diagram illustrating another alternative embodiment of the growing stent of FIG. 1A and 1B, the growing stent is shown in an expanded state to define an internal channel with a first given cross section.

In FIG. 2C is an exemplary detailed diagram illustrating yet another alternative embodiment of the growing stent of FIG. 1A and 1B, the growing stent is shown in an expanded state to define an internal channel with a second predetermined cross section.

In FIG. 2D is an exemplary detailed diagram illustrating yet another alternative embodiment of the growing stent of FIG. 1A and 1B, the growing stent is shown in an expanded state to define an internal channel with a third predetermined cross section.

In FIG. 3A is an exemplary detailed diagram illustrating another alternative embodiment of the growing stent of FIG. 1A and 1B, in which the inner channel includes an open channel.

In FIG. 3B is an exemplary detailed diagram illustrating an alternative embodiment of the growing stent of FIG. 3A, wherein the growing stent comprises one or more leaflets extending into the internal canal.

In FIG. 4A is an exemplary detailed diagram illustrating a further alternative embodiment of the growing stent of FIG. 1A and 1B, wherein the growing stent comprises a plurality of arcuate elements.

In FIG. 4B is an exemplary detailed diagram illustrating a further alternative embodiment of the growing stent of FIG. 4A, in which pairs of arcuate elements interact with each other.

In FIG. 5A is an exemplary detailed diagram illustrating an embodiment of the growing stent of FIG. 4A and 4B, with the growing stent shown in the initial state for implantation.

In FIG. 5B is an exemplary detailed diagram illustrating another alternative embodiment of the growing stent of FIG. 4A and 4B, the growing stent is shown in an expanded state to define an internal channel with a first given cross section.

In FIG. 5C is an exemplary detailed diagram illustrating yet another alternative embodiment of the growing stent of FIG. 4A and 4B, the growing stent is shown in an expanded state to define an internal channel with a second predetermined cross section.

In FIG. 5D is an exemplary detailed diagram illustrating yet another alternative embodiment of the growing stent of FIG. 4A and 4B, the growing stent is shown in an expanded state to define an internal channel with a third predetermined cross section.

In FIG. 6A is an exemplary detailed diagram illustrating a two-dimensional planar view of the growing stent of FIG. 4A and 4B.

In FIG. 6B is an exemplary detailed diagram illustrating a side view of the growing stent of FIG. 6A.

In FIG. 7A is an exemplary detailed diagram illustrating an embodiment of the catheter delivery system for implanting the growing stent of FIG. 1A and 1B.

In FIG. 7B is an exemplary detailed diagram illustrating an alternative embodiment of the catheter delivery system of FIG. 7A, with the catheter delivery system shown in a closed configuration.

In FIG. 8A is an exemplary detailed diagram illustrating an embodiment of the catheter delivery system of FIG. 7A and 7B, wherein the delivery catheter of the catheter system

- 3 040514 delivery is located near the implantation site.

In FIG. 8B is an exemplary detailed diagram illustrating an embodiment of the catheter delivery system of FIG. 8A, with the catheter delivery system shown in an open configuration.

In FIG. 8C is an exemplary detailed diagram illustrating an embodiment of the catheter delivery system of FIG. 8B, wherein the catheter delivery system expands the growing stent from the initial state to the expanded state.

In FIG. 8D is an exemplary detailed diagram illustrating an embodiment of the catheter delivery system of FIG. 8C with the catheter delivery system retracted from the implant site, leaving an expanded growing stent.

In FIG. 9 is an exemplary flowchart illustrating an embodiment of the method for implanting the growing stent of FIG. 1A and 1B via a balloon catheter delivery system.

It should be noted that the figures are not drawn to scale and that elements of similar structures or functions may generally be represented by the same reference numerals for illustrative purposes throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the preferred embodiments. The figures do not illustrate every aspect of the described embodiments and do not limit the scope of the present invention.

Information confirming the possibility of carrying out the invention

Because currently available stents have certain, limited ranges of service and, when implanted early in development, cannot grow to adult size, an expandable growing stent that can maintain adequate strength over a given range of expansion may be desirable and provide the basis for a wide range of systemic applications such as implantation in newborns and other young patients with subsequent expansion as patients grow. This result can be achieved in accordance with the selected embodiments disclosed herein by means of a growing stent 100 as illustrated in FIG. 1A and 1B.

In FIG. 1A shows an expanding stent 100 comprising an elongated stent frame (or body) 110 to form an internal channel 120. An expanding stent 100 may be implanted into a patient vessel (or lumen) 300 (shown in FIGS. 8A-8D) to keep it open or otherwise reinforce the lumen 300. The stent body 110 may be provided in its original (either unexpanded or compressed) state, as shown in FIG. 2A. Initially, stent body 110 may have any predetermined initial size, shape, diameter, cross section, and/or other geometric parameter to facilitate insertion of growing stent 100 into lumen 300. Initial volume, shape, diameter, cross section, and/or other geometric parameter D body 110 stent may depend on the application.

After placement in the selected implant site 310 (or other area of interest) shown in FIG. 8A-8D, within the lumen 300, the stent body 110 can be expanded from the initial state to the first expanded state, as shown in FIG. 1A. In the first expanded state, the stent body 110 may have a first predetermined expanded size, shape, diameter, cross section, and/or other geometric parameter D. The stent body 110, when expanded in the first expanded state, may define an internal channel 120. The internal channel 120 may having a first predetermined diameter, cross section, and/or other geometric parameter D1 to facilitate the unimpeded (or normal) flow of body fluid, such as blood, bile, or other lumen-related fluid, through lumen 300 through growing stent 100.

In selected embodiments, the expanded stent body 110 may include a body wall 112 that defines an internal channel 120. The body wall 112, for example, may include an internal surface 114 for defining an internal channel 120. The internal channel 120 preferably extends from the proximal end region 130 of the body 110 of the stent to the distal end region 140 of the stent body 110, as illustrated in FIG. 1A. Thus, the growing stent 100 may allow body fluid to flow, preferably unobstructed, from the proximal end region 130 to the distal end region 140 through the internal channel 120. In other words, the growing stent 100 may have a generally tubular shape.

Advantageously, the stent body 110 can be further expanded from a first expanded state to a second expanded state, as shown in FIG. 1B. The stent body 110 may be expanded to a second expanded state based on one or more preselected criteria. Exemplary pre-selected criteria may include, but are not limited to, pre-selected duration after implantation of growing stent 100, lumen 300 status, and/or growth (or other size change or other condition) of the patient. In the second expanded state, the stent body 110 may have a second predetermined expanded size, shape, diameter, cross section, and/or other geometric parameter that is larger than the first predetermined expanded size, shape, diameter, cross section, and/or

- 4 040514 another geometric parameter of the body 110 of the stent.

The stent body 110, when expanded in the second expanded state, may define an internal channel 120 with a second predetermined diameter, cross section, and/or other geometrical parameter D ₂ to maintain an unobstructed flow of body fluid through the lumen 300 through an even more expanded growing stent 100. In other words, in other words, the stent body 110 may be tubular and/or may have relatively wide locking end portions (not shown) in the proximal and distal end regions 130, 140 when expanded in the second expanded state. Although shown and disclosed to have two extended states (with reference to FIGS. 1A and 1B for illustration purposes only), growing stent 100 can support any given number of extended states. The stent body 110, when expanded in the second expanded state, may define an internal channel 120 with an appropriate predetermined diameter, cross section, and/or other geometric parameter to maintain an unobstructed flow of body fluid through the lumen 300 through the growing stent 100. The predetermined number of expanded states and the corresponding given diameters, cross-sections and/or other parameters, for example, may depend on the application.

The growing stent 100 advantageously can be expanded to a wide range of anatomical diameters needed to treat pathological narrowing throughout the life of the patient. In a slightly different way, through a given number of expanded states supported by growing stent 100, growing stent 100 can be configured to provide a wide range of anatomical diameters. The growing stent 100, for example, can be compressed on a delivery catheter 210 small enough for a neonatal patient, in particular the compressed growing stent 100 is less than 8 French, with the possibility of further expansion to adolescent and/or adult sizes, greater than 18 mm in diameter.

In FIG. 2A-2D illustrate selected embodiments of a growing stent scaffold at various cycles throughout a patient's life and as the diameter of the vessel (or lumen) 300 (shown in FIGS. 8A-8D) of the patient increases. In this particular example, the growing stent scaffold 110 can maintain strength at various diameters. In FIG. 2A, the growing stent 100 is shown in its initial state for implantation. Initially, the stent body 110 may have a predetermined initial size, shape, diameter, cross section, or other geometric parameter, such as 2 mm, to facilitate insertion of the growing stent 100 into the lumen 300.

When growing stent 100 is in the expanded state, stent body 110 may define an internal channel 120 with any suitable predetermined diameter, cross section, or other dimension D. Stent body 110, for example, may define internal channel 120 with a first predetermined diameter, cross section, or other geometric parameter D equal to 8 mm, as shown in Fig. 2B with a second predetermined diameter, cross section, or other geometrical parameter D of 15 mm, as shown in FIG. 2C, and/or a third predetermined diameter, cross-section or other geometrical parameter D equal to 20 mm or more, as shown in Fig. 2D, unlimited. Thus, a growing stent 100 may be provided to hold open the narrow vessel 300 (shown in FIGS. 8A-8D) and allow normal flow of blood or other body fluids.

As an example, an expandable stent 100 can be implanted into a vessel (or lumen) 300 (shown in FIGS. 8A-8D) of an infant patient by expanding to a diameter of less than 10 mm and have the proper strength to expand over the lifetime of the patient to a size much larger than 18 mm. An exemplary growing stent 100 may be passed through an infant patient vessel 300 via a delivery catheter 210 of catheter delivery system 200 (shown together in FIGS. 7A and 7B) that is significantly less than 8 French in diameter, and in some embodiments, less than 5 French in diameter. etc.

When the channel 120 formed by the stent body 110 is tubular, it may include an open channel as illustrated in FIG. 3A. The growing stent 100 can optionally support valvular function. In selected embodiments, for example, growing stent 100 may comprise one or more leaflets 150 as shown in FIG. 3B. The flaps 150 can be attached to the inner surface 114 of the wall 112 of the body and extend into the channel 120 formed in the body 110 of the stent. Leaflets 150 can thus provide valvular function in growing stent 100.

An alternative embodiment of a growing stent 100 is shown in FIG. 4A and 4B. In FIG. 4A shows a growing stent 100 comprising an elongated stent frame (or body) 110 to form an internal channel 120. As described in more detail with reference to FIG. 1A and 1B, an expanding stent 100 may be implanted in a patient vessel (or lumen) 300 (shown in FIGS. 8A-8D) to hold it open or otherwise strengthen the lumen 300. The stent body 110 may be provided in its original (or non-expanded) , or compressed) state, as shown in FIG. 5A. Initially, the stent body 110 may have any desired initial size, shape, diameter, cross section, and/or other geometry to facilitate insertion of the growing stent 100 into

- 5 040514 lumen 300. The original size, shape, diameter, cross section and/or other geometric parameter D of the body 110 of the stent may depend on the application.

After placement at the selected implant site 310 (or other region of interest) (shown in FIGS. 8A-8D) within the lumen 300, the stent body 110 can be expanded from the initial state to the first expanded state as shown in FIG. 5V. In the first expanded state, the stent body 110 may have a first predetermined expanded size, shape, diameter, cross section, and/or other geometric parameter D. The stent body 110, when expanded in the first expanded state, may define an internal channel 120. The internal channel 120 may having a first predetermined diameter, cross section, and/or other geometric parameter D1 to facilitate the unobstructed (or normal) flow of body fluid, such as blood, bile, or other lumen-related fluid, through the lumen 300 through the growing stent 100.

In selected embodiments, the expanded stent body 110 may comprise a body wall 112 that defines an internal channel 120 that preferably extends from the proximal end region 130 of the stent body 110 to the distal end region 140 of the stent body 110, as illustrated in FIG. 4A. Thus, the growing stent 100 may allow body fluid to flow, preferably unobstructed, from the proximal end region 130 to the distal end region 140 through the internal channel 120. In other words, the growing stent 100 may have a generally tubular shape and/or may support valvular function, as discussed in the present application with reference to FIG. 3A and 3B.

As shown in FIG. 4A, one or more selected stent body (or scaffold) connections 110 may be formed from scaffold elements that include respective arcuate elements, such as arcuate elements 174, 176. Each of the arcuate elements 174, 176 may define a central recess 172. Growing stent 100 may expand as described herein such that the diameter, cross section, and/or other dimension D of inner channel 120 may increase from a smaller dimension D _A as shown in FIG. 4A to the larger dimension DB as shown in FIG. 4B as described in this application. Expanding the growing stent 100 may include expanding between two predetermined states. For example, expansion of growing stent 100 may include expansion from the initial state illustrated in FIG. 5A to the first extended state illustrated in FIG. 5B, expanding from the first expanded state illustrated in FIG. 5B to the second extended state illustrated in FIG. 5C and/or expanding from the second expanded state illustrated in FIG. 5C to the third extended state illustrated in FIG. 5D, or any other expansion of the growing stent 100 without limitation.

As the growing stent 100 expands, the arcuate members 174, 176 may converge. The arcuate elements 174, 176 are thus cooperative such that the central recess 172 of the arcuate element 174 may be cooperative with the central recess 172 of the arcuate element 176. The arcuate elements 174, 176, in other words, may comprise cooperating arcuate elements. The interacting arcuate elements 174, 176 may thus define a central channel 178. The central channel 178 may be formed between the interacting arcuate elements 174, 176 and comprise the intersection of the central recess 172 of the arcuate element 174 and the central recess 172 of the arcuate element 176.

The arcuate members 174, 176 may advantageously provide axial flexibility to the growing stent frame 110, for example, if the arcuate members 174, 176 are thinner than the width 160 of the legs of the remainder of the growing stent 100. In some embodiments, C-shaped arcuate members 174, 176 may be used. to allow for deformation contrary to the normal compressive strength provided by the growing stent framework 110. The arcuate members 174, 176 may provide a point of leverage in the structure of the scaffold 110, potentially allowing the scaffold 100 to flex upon insertion to a target location, or possibly after deployment, depending on the configuration required for either. The bending may be due to deformation of the C-shape, which collapses on its own and/or opens up to become a straighter line, depending on the direction of deformation.

As discussed in more detail with reference to FIG. 1A, 1B, and 2A-2D, the growing stent 100 of FIG. 4A and 4B advantageously can expand over a wide range of anatomical diameters needed to treat pathological constrictions throughout a patient's lifetime. In a slightly different way, through a given number of expanded states supported by growing stent 100, growing stent 100 can be configured to provide a wide range of anatomical diameters. The growing stent 100, for example, can be compressed on a delivery catheter 210 small enough for a neonatal patient, in particular the compressed growing stent 100 is less than 8 French, with the possibility of further expansion to adolescent and/or adult sizes, greater than 18 mm in diameter.

In FIG. 5A-5D illustrate selected embodiments of a growing stent scaffold at various cycles throughout a patient's life and as vessel diameter (or light transmission) 300 (shown in FIGS. 8A-8D) increases in the patient. In this particular example, the growing stent scaffold 110 can maintain strength at various diameters. In FIG. 5A, the growing stent 100 is shown in its initial state for implantation. Initially, the stent body 110 may have a predetermined initial size, shape, diameter, cross section, or other geometric parameter, such as 2 mm, to facilitate insertion of the growing stent 100 into the lumen 300.

When the growing stent 100 is in the expanded state, the stent body 110 may define an internal channel 120 with any suitable predetermined diameter, cross section, or other dimension D. The stent body 110, for example, may define an internal channel 120 with a first predetermined diameter, cross section, or other geometric parameter D equal to 8 mm, as shown in Fig. 5B with a second predetermined diameter, cross section, or other geometrical parameter D of 15 mm, as shown in FIG. 5C and/or a third predetermined diameter, cross section, or other geometrical parameter D of 20 mm or more, as shown in FIG. 5D, unlimited. Thus, a growing stent 100 may be provided to hold open the narrow vessel 300 shown in FIG. 8A-8D and ensure normal flow of blood or other body fluids.

As an example, an expandable stent 100 can be implanted into a vessel (or lumen) 300 (shown in FIGS. 8A-8D) of an infant patient by expanding to a diameter of less than 10 mm and have the proper strength to expand over the lifetime of the patient to a size much larger than 18 mm. An exemplary growing stent 100 may be passed through an infant patient vessel 300 via a delivery catheter 210 of catheter delivery system 200 (shown together in FIGS. 7A and 7B) that is significantly less than 8 French in diameter, and in some embodiments, less than 5 French in diameter. etc.

As shown in FIG. 6A and 6B, the geometry of a growing stent, including scaffold strut width 160, scaffold thickness 162, cell count 164, and/or cell angle 166, can help maintain strength over a wide range of deployments and expansions. The frame strut width 160 and the frame thickness 162 can be used to determine the radial strength of the growing stent frame 110 and the number of cells 164, increasing the impact of these characteristics. In one embodiment, the growing stent frame 110 can be optimized to reduce the effect of growing stent 100 compressibility. Compressibility is the length contraction that can occur when growing stent 100 expands from a collapsed state to a selected expanded state. The cell angle 166 and cell length 164 of the growing stent can be optimized to reduce the amount of compressibility of the growing stent to more predictably deploy the growing stent 100 through expansion, such as balloon expansion.

The width of the scaffold strut joints can help ensure that the growing stent 100 is compressed small enough to be passed through the infant's blood vessels 300. Keeping the strut connection width 168 small to allow for less compression of said number of cells 164 in growing stent 100 can facilitate delivery. The connection width 168 is preferably large enough to allow a large range of expansion so that subsequent expansion does not result in significant scaffold stress and deformation, resulting in a small range of optimization of the growing stent connection width 168 for this purpose. The growing stent scaffold material can provide these properties, providing strength over a wide range of operations, despite the thin walled nature of the growing stent 100, which allows the growing stent 100 to be compressed small enough to be delivered to neonatal patients.

The growing stent frame 110 can be optimized to allow for increased wall thickness 162 relative to the original tubes used for the metal structure. Limiting the connection width 168 to a minimum relative to the strut width 160 may allow the wall thickness 162 of the frame 110 to be increased, which may prevent the growing stent 100 from springing out when a radial force is applied. Therefore, the resistance to failure of the scaffold 110 can be increased, which reduces the recoil effect of the vessel 300, increasing the radial force of the growing stent 100 over the entire range of diameters required for expansion and providing a rigid structure to hold the vessel 300 open.

Since particular strength is required for this group of patients and the framework must be compressed to extremely small diameters, there are specific formulas for calculating strut width 160, wall thickness 162, connection size and cell count 164 that provide an optimized version that allows wide re-expansion. growing stent 100. In Equation 1, one formula for optimizing growing stent 100 is given as an example. According to Equation 1, the minimum compression diameter of growing stent 100 can be represented as (SVZ + D) * K

----------+(2*ST)

7D (Equation 1)

- 7 040514 where SW is the width 160 of the post,

J - width 168 connection,

N - number of cells 164, a

ST is the thickness of the rack relative to the wall thickness 162 of the original tubes.

Equation 1 allows certain parameters to be set based on the recoil force required to maintain proper strength in the desired range of use by increasing the thickness of the strut 162 and maintaining compression to the desired small diameters. By minimizing the joint so that it is only slightly larger than the leg width 160 of the growing stent 100, the smallest compression diameter can be calculated as a function of the leg width 160 and joint width 168 times the number of cells 164, according to Equation 1.

In some embodiments of the growing stent 100, the thickness 162 of the body (or scaffold) wall 112 may be minimized to prevent thrombus formation and/or stenosis in the vessel 300. Increasing the thickness 162 of the scaffold wall 112 may cause the diameter of the vessel 300 to decrease after expansion because the wall 112 scaffold may block vessel 300. Additionally and/or alternatively, increasing the thickness 162 of scaffold wall 112 may provide more material for clot attachment. More material in the stent scaffold 110 may promote greater endothelialization by allowing cells 164 to attach foreign bodies to themselves.

In an optimized embodiment of a growing stent 100, strength and thickness factors 162 can be calculated to obtain the best results for a growing patient. Using a vessel strength study, a growing stent scaffold can be optimized to provide adequate strength over a wide range of performance using one or more of the above factors. The growing stent 100 may have certain parameter ranges that are unique to a given application that distinguish it from traditional stent scaffolds. By adding the resulting stent radial force and breaking force as an output, for example, Equation 1 can be optimized for strength, allowing the optimized stent scaffold 110 to grow within a specific range.

Equation 1 assumes that the measured strut length of the growing stent scaffold is constant and determined, since changing strut length can affect the resulting strength. In one optimized embodiment of the growing stent 100, the strut length can be determined to ensure that the stent scaffold 110 does not experience high stresses and strains that can lead to scaffold defects such as deformation and/or fracture. Increasing the length of the strut itself may result in an increase in the expansion diameter, but may result in a decrease in the resulting radial force. Therefore, an optimized embodiment of growing stent 100 may include the shortest strut length that provides acceptable stress and stretch to stent scaffold 110 over the intended diameter range of growing stent 100.

Once the shortest strut length for the growing stent 100 has been determined, Equation 1 can be used to optimize the scaffold 110. Although two or more factors, or in some cases all of the factors, may be changed together, some parameter changes may show a pattern in the outgoing radial strength of the scaffold 110, allowing use different embodiments of the same stent design as growing stent 100. In some embodiments of growing stent 100, these parameters can be optimized for a small enough minimum compression to not harm the vessels of 300 neonatal patients while providing adequate strength at large adult vessel sizes, as opposed to commercially available stents that are optimized for very specific adult diameter ranges.

The growing stent 100 preferably has adequate radial strength to keep the vessel 300 open at a given diameter, for example, using a stent expansion system 260 (shown in FIG. 7A), such as a balloon, to expand the growing stent 100 to a specific diameter and the growing scaffold 110 a stent having sufficient radial strength to maintain a certain diameter without balloon support. However, the radial strength and other properties of the growing stent 100 may affect the fatigue potential of the growing stent scaffold 110. Fatigue can result from continuous and repetitive movement that stresses and stretches the frame 110.

In some embodiments, one or more properties of the stent frame 110 may be optimized to ensure that unacceptable fatigue does not occur during the life of the growing stent 100. This can be done in a variety of ways. Exemplary methods of preventing unacceptable fatigue may include increasing the radial strength of the growing stent 100 to limit cyclic contraction and expansion in the vessel 300 and/or lengthening the struts themselves to create more relaxed cell structures that are less prone to fatigue. The level of ductility of the metal or other material selected for the stent frame 110 can also influence the level of stretch. Excessive fatigue and stretching of the growing stent scaffold 110 can lead to

- 8 040514 deformation and / or potential destruction of the metal or other material from which the growing stent 100 is made.

In some embodiments of the growing stent 100, the scaffold 110 may be cut from the tube using a laser cutting machine (not shown). The laser cutting machine can accurately cut through the 162 thickness of the tube wall to create a honeycomb structure. After cutting, waste material can be collected and/or removed between the cut cell racks. In many cases, the laser cutting machine may leave jagged edges on the growing stent scaffold 110 and/or metal scaffold, which are preferably ground to the inside diameter to ensure that there are no bumps.

Additionally and/or alternatively, in some embodiments, the growing stent scaffold 110 may be electropolished to remove the outer layer of metal from the scaffold 110, which smoothes the edges and finishes the scaffold 110 for implantation. Electropolishing in many cases uses electric current through a liquid bath to evenly distribute the material to be removed from the outer layers of metal on the scaffold 110, which often results in the polishing sheen remaining on the growing stent 100. In some embodiments, such as those that use NITINOL or other shape-changing materials in the scaffolds, the desired shape can be formed by heating and tempering.

The diameter of the tubes used as the base for the stent frame 110 can affect the strength of the frame 110. Larger diameter tubes are less trapezoidal if the tube wall thickness 162 is maintained. Although the stent frame 110 can be adjusted to be cut to any tube diameter, as long as the wall thickness 162 remains accurate, the trapezoidal struts associated with small tubes can result in a decrease in radial strength in the desired range, as the rack is made with less material. In an optimized embodiment of the growing stent 100, the scaffold 110 may be cut from tubing with a specific thickness 162 and/or diameter to provide adequate strength throughout the range of use.

In selected embodiments, the growing stent 100 may include an uncoated metal scaffold 110 and/or have a blood-impervious coating on the scaffold segment 110. The blood-impervious coating allows vessels to grow inward and isolates the vessel 300 from leaking blood through the growing stent 100. The cover may be of a woven material such as polyethylene terephthalate (PET) and/or a fluoropolymer such as some polytetrafluoroethylenes. The cover seals and works over the entire diameter range of the growing stent scaffold 110 and can expand with the scaffold 110 throughout the entire growth period of the patient. In one embodiment, a blood-impervious cover may be attached to each diamond cell of the growing stent 100, matching the shape of each cell. The fabric in this embodiment may be sewn or attached to the scaffold 110 using a suture or other suitable attachment method.

In one exemplary embodiment, a blood-tight cover may be attached to the distal and proximal ends 130, 140 (shown in FIGS. 1A and 1B) of the growing stent frame 110 and/or at one or more other predetermined locations along the growing stent frame 110 for ensure proper expansion. The coating may be attached in any suitable manner, such as by stitching and/or tacking as described herein, and/or by selective welding, to provide attachment to the scaffold 110. Additionally and/or alternatively, the scaffold 110 of the growing stent may be immersed into a polymer that forms a flexible film between cells 164 of scaffold 110 to provide a blood-tight coating. In this embodiment, the scaffold 110 may be immersed in liquid polymer and slowly removed, allowing the polymer to dry and create a flexible coating upon removal. The polymer can be cured in air and/or in an oven to obtain the desired properties of the material.

In some embodiments, one or both of the end regions 130, 140 of the growing stent 100 may broaden outwardly relative to the longitudinal axis of the growing stent 100. The widened end regions 130, 140 may advantageously assist in anchoring the growing stent 100 at the desired location in the wall of an artery or other lumen. The broadening may be implemented in any suitable manner. For example, broadening can be implemented by bending outwardly the ends of the selected end region 130, 140 using material properties and/or shaping. In another embodiment, expansion by a balloon or other expandable element (not shown) with a curved outward shape may be used. Additionally and/or alternatively, one or both end regions 130, 140 may be widened inwards to prevent aneurysms using similar techniques.

Similarly, aneurysms can be prevented by blunting one or both end regions 130, 140 of growing stent 100. Blunt end regions 130, 140 can be created in growing stent 100 in some embodiments by attaching round lugs and/or ends of various sizes to reduce sharpness. frame 110 growing stent. For example, end regions 130, 140 may be round, hooked, or any other non-invasive shape. In another embodiment of the growing stent 100, elements on the growing stent 100 may be used to interact with the anatomy and hold the growing stent 100 in the desired location. In this embodiment, the growing stent 100 may have sharper edges cut into the growing stent scaffold 110 and/or it may use some sort of pin for anchoring, whether through the growing stent scaffold 110 or adding knots of suture material to provide fixation in the vessel. 300.

In another embodiment of the stent frame 110, one or both of the end regions 130, 140 may have material removed from the remainder of the stent frame 110. Material can be removed, for example, from the strut width 160 of the stent frame 110, from the strut thickness 162 of the growing stent 100, or both. The removal of material allows the thinner end regions 130, 140 of the growing stent 100 to be more flexible than the thicker stent body 110, allowing for less penetration into blood vessels and the potential for less invasion into the patient's body. Flexibility can be used in this embodiment of the scaffold 110 to prevent aneurysms and vascular irritation. If the embodiment of growing stent 110 is balloon dilatable, for example, thinned end regions 130, 140 may cause less resistance to the balloon and may be used as a tool to prevent movement of growing stent 100 during balloon deployment.

The end regions 130, 140 of the growing stent 100 can enter the surrounding vessel 300 or other anatomical object into a pathological constriction using a radial force. The flares at the end portions 130, 140 can be advantageously used to attach the growing stent 100 to the surrounding anatomy. The flares serve as a stopper that can secure the growing stent 100 in place. When an axial force is applied to the growing stent 100, the flares can be pushed into the surrounding anatomy to prevent the growing stent 100 from moving.

Expansions and expansions of the growing stent 100 can be implemented naturally through the expanding properties of the growing stent 100, such as material selection, and/or manually using a pressurized balloon or other stent expansion system 260 to expand the scaffold 110 to a larger diameter than the vessel 300c. stretching the walls of the vessel 300 and fixing the growing stent 100 inside the vessel 300 due to the radial force (strength). As the patient grows, the diameter of the growing stent 100 may increase due to material properties and self-expansion and/or later balloon dilatation to increase the diameter of the growing stent 100 and ensure that the growing stent 100 maintains fixation through excess expansion and the resultant radial force of the scaffold 110 .

The growing stent 100 can be made from one or more of a variety of conventional balloon-expandable stent materials, or in alternative embodiments for self-expanding growing stents. As non-limiting examples, the growing stent 100 can be made from any suitable material such as a metal or metal alloy, including stainless steel, cobalt-chromium, nitinol, elgiloy, or, for example, a polymer. For self-expanding embodiments, the growing stent 100 may be made from a shape memory material such as, for example, nitinol.

The growing stent 100 can advantageously be configured to expand into constricted vessels 300 to a selected expanded state, particularly adult size, and maintain adequate strength for the vessel openings over the range of desired expansion. In selected embodiments, a transvascular technique may be used to insert and implant a growing stent 100 in neonates and other young patients using a catheter delivery system 200 as shown in FIG. 7A and 7B. As shown in FIG. 7A, an exemplary catheter delivery system 200 may include a flexible delivery catheter 210, and advantageously it may insert and implant the growing stent 100 in a less invasive manner than open heart surgery. The delivery catheter 210 may be advanced to the heart (or other implantation site 300 as shown in FIGS. 8A-8D) and surrounding vasculature through a groin vessel 300 or other connecting vessel 300.

The end portion 220 of the delivery catheter 210 is shown to include an inner shaft 240 and an outer shaft 250. One or more shafts 240, 250 may be made from a flexible plastic such as Pebax or other nylon and contain open lumens. The delivery catheter 210 preferably includes a flexible catheter. The flexibility may allow proper patency through the human vasculature, allowing the growing stent 100 to be delivered to the desired location. The plastics used for the delivery catheter 210 may be biocompatible so as not to cause harm to the patient.

In selected embodiments, the growing stent 100 may be placed in its rest (or collapsed) state on the end portion 220 of the delivery catheter 210. In other words, the growing stent 100 in its rest state can accommodate the inner shaft 240 through the inner channel 120 shown in FIG. 1A and 1B. Thus, the growing stent 100 may be positioned between the inner shaft 240 and the outer shaft 250 of the delivery catheter 210. The end portion 220 of the delivery catheter 210 may also include an optional stent expansion system 260, such as a balloon, to expand the growing stent. 100 from the original state to the specified extended state. In selected embodiments, the stent expansion system 260 may be at least partially located within the internal channel 120 to facilitate subsequent expansion of the growing stent 100.

Once the growing stent 100 is properly positioned on the end portion 220 of the delivery catheter 210, the delivery catheter system 200 can be brought into a closed configuration as shown in FIG. 7B. In other words, catheter delivery system 200 may transition from the open configuration shown in FIG. 7A to the closed configuration shown in FIG. 7B. In FIG. 7B shows that the outer shaft 250 of the delivery catheter 210 moves distally to the optional anterior cone 230 of the delivery catheter 210. In other words, the growing stent 100 may be positioned between the inner shaft 240 and the outer shaft 250 when the delivery catheter 210 is in a closed configuration. Thus, the outer shaft 250 may provide a protective sheath for the growing stent 100 to be inserted and advanced through the vessel (or lumen) 300 of the patient.

During implantation, the delivery catheter 210 of the catheter delivery system 200 may pass through the vasculature with the growing stent 100 and the stent expansion system 260 covered by the outer shaft 250. Thus, the delivery catheter 210 may be passed through the vessel (or lumen) 300 of the patient until until the end portion 220 reaches the implantation site 310, such as an abnormal constriction or other affected area, as illustrated in FIG. 8A. Once placed near the implantation site 310, the catheter delivery system 200 can be brought into an open configuration, as illustrated in FIG. 8B. In other words, catheter delivery system 200 may transition from the closed configuration shown in FIG. 7B to the open configuration shown in FIG. 8B.

In an open configuration, the outer shaft 250 of the delivery catheter 210 may be positioned proximal to or spaced from the anterior cone 230. Thus, the delivery catheter 210 may expose the growing stent 100 at the implantation site 310. When the growing stent 100 is adjacent to the implant site 310, the stent expansion system 260 may be activated to expand the growing stent 100 from its original (either non-expanded or compressed) state, as shown in FIG. 8B to the first extended state in FIG. 8C. In selected embodiments, the stent expansion system 260 may include a balloon that can be inflated to expand the growing stent 100.

Additionally and/or alternatively, the growing stent 100 can optionally be expanded by expanding the distal portion of the growing stent 100 while the proximal portion of the growing stent 100 is attached to the delivery catheter 210 without using the stent expansion system 260. After expanding the distal portion of the growing stent 100, the proximal portion of the growing stent 100 may be detached from the delivery catheter 210 and expanded into the lumen 300. The proximal portion of the growing stent 100, for example, may be expanded all at once or in stages.

In the first expanded state, growing stent 100 may have a first predetermined expanded size, shape, diameter, cross section, and/or other geometry, as discussed in more detail above with reference to FIG. 1A. The stent expansion system 260 can be deactivated upon returning to its original volume. If the stent expansion system 260 includes a balloon, the balloon can be deflated. The delivery catheter 210 can then be removed from the lumen 300 after the growing stent 100 in the first expanded state has been successfully deployed at the implant site 310 as shown in FIG. 8D.

Thus, the growing stent 100 can be implanted with its functional volume at the site 310 of implantation. If necessary, the growing stent 100 can be further expanded to a larger volume, in particular, corresponding to the size of a teenager and/or the size of an adult. For example, similar to implantation, another delivery catheter 210 may be passed through the patient's vasculature and advanced through vessel 300 until end portion 220 reaches growing stent 100 at implantation site 310. The stent expansion system 260 of the delivery catheter 210 may be located in the internal channel 120 shown in FIG. 1A of growing stent 100 and activated to expand growing stent 100 from the first expanded state shown in FIG. 8C to the second extended state shown in FIG. 1B.

In the second expanded state, the growing stent 100 may have a second predetermined expanded size, shape, diameter, cross section, and/or other geometric parameter that is larger than the first predetermined expanded size, shape, diameter, cross section, and/or other geometric parameter of the growing stent. 100 in the first expanded state, as described in more detail above with reference to FIG. 1b. The stent expansion system 260 can be removed and the delivery catheter 210 can be removed from the lumen 300 after the second expanded state growing stent 100 is successfully deployed at the implant site 310 as discussed above with reference to FIG. 8D.

The growing stent 100 can advantageously be implanted in a neonatal patient and

- 11 040514 expanded as needed throughout the life of the patient. Once delivered and implanted with a specific diameter, the growing stent 100 can be expanded to a larger size at a later time. This applies when the vessels originally housing one embodiment of the growing stent 100 continue to grow, for example, during the patient's growth from infancy to adolescence to adulthood. Because the growing stent 100 may have adequate strength across all applicable growth ranges, a separate balloon or other stent expansion system 260 at a later stage in the patient's growth cycle may be brought up to the growing stent 100 at the implant site 310 . This further expansion of the growing stent 100 may occur as needed as the individual patient grows.

In selected embodiments, the delivery catheter 210 may comprise a balloon catheter with a balloon 260 to expand the growing stent 100. The balloon catheter may insert and deploy the growing stent 100 in a manner similar to the delivery catheter 210 described as insertion and deployment of the growing stent 100 with reference to fig. 8A-8D. In FIG. 9, for example, shows an exemplary method 400 for implanting the growing stent 100 shown in FIG. 8A-8D through a balloon catheter system. Method 400 includes delivering growing stent 100 to implantation site 310 in patient vessel (or lumen) 300 (shown collectively in FIGS. 8A-8D) at 410. The balloon catheter may be advanced through patient vessel (or lumen) 300 until it will not reach the implantation site 310 .

Once positioned near the implant site 310, the balloon catheter may be brought into an open configuration or deployed at 420, which results in the opening of the growing stent 100 at the implant site 310. In other words, catheter delivery system 200 may transition from the closed configuration shown in FIG. 7B to the open configuration shown in FIG. 8B. The balloon 260 may be filled with fluid and thus expand in size at step 430. Positioned in the inner channel 120 shown in FIG. 1A and 1B of an expandable stent 100, an expandable balloon 260 can expand an expandable stent 100 from its original (either non-expanded or compressed) state, as shown in FIG. 8B to the first extended state in FIG. 8C.

Thus, the growing stent 100 in the first expanded state can engage and/or be embedded in the wall of the vessel 300 at the implant site 310 at 440. The balloon 260 can then be recompressed and removed from the patient's body, leaving the growing stent 100 in engagement with the vessel. 300. In other words, growing stent 100 can be reset and, after balloon expansion 260, can keep vessel 300 open without maintaining balloon 260 after balloon dilatation. Thus, the growing stent 100 in the first expanded state can be successfully deployed at the implant site 310 .

Additionally and/or alternatively, the balloon catheter may include an optional anterior cone 230 (shown in FIGS. 7A and 7B). Front cone 230 can facilitate transitions and passage through vessel 300 and serve as a closure end region for balloon 260 itself. Front cone 230 may be constructed using plastics similar to rods 240, 250, often triangular in shape, to facilitate transitions and passage through vessels 300 The balloon 260 can advantageously be designed with a thin plastic wall that can be compressed to fit within the delivery catheter 210 and ensure that the profile is small enough to be inserted into the desired patient vasculature. The balloon 260 may be attached to the inner plastic shaft 240 and sealed at the distal end. The internal lumen of the plastic rod 240 can direct the injected fluid, such as saline, from the proximal end of the rod to the balloon 260. When the balloon 260 is filled with fluid, the balloon 260 can expand to the calculated diameter.

When the growing stent 100 is compressed on the balloon 260, the balloon 260 can be compressed to a small diameter and without being built into the ribs to hold the growing stent 100 in place. When outer rod 250 is retracted to deploy growing stent 100 on balloon 260, balloon 260 may not have sufficient resistance to maintain the position of growing stent 100 on balloon 260. In some embodiments, retraction of outer rod 250 to deploy growing stent 100 may result in that the outer shaft 250 will snap onto the growing stent 100 and pull the growing stent 100 away from the balloon 260.

In some balloon catheter embodiments, this problem can be mitigated by using a separate catheter (not shown) positioned between the balloon shaft and outer shaft 250. This middle catheter can be used as a backstop for growing stent 100 during outer shaft retraction. In this embodiment, the outer rod 250 can be retracted through the growing stent 100 and the middle catheter as the middle catheter is fixed relative to the balloon catheter, holding the growing stent 100 in place during deployment. After the growing stent 100 and the middle catheter are deployed, the middle catheter can be retracted through the balloon 260 to allow expansion. This ensures that the growing stent 100 remains compressed in the proper position for balloon expansion at the target location 310 in the patient's body.

- 12 040514

In another alternative embodiment of the balloon catheter, instead of a back-stop for growing stent 100, the middle catheter may overlap with growing stent 100, creating a sock-like device to hold growing stent 100 in place. This thin sock catheter can maintain the position of the stent during retraction of the outer rod 250 and allow for proper inflation of the balloon 260. In some embodiments, this sock catheter can be retracted prior to expansion of the balloon 260 if it overlaps with the growing stent 100. In others in alternative embodiments, the sock catheter may only cover the balloon 260 and may be expanded with the balloon 260 and removed with the balloon catheter.

In embodiments of a catheter delivery system 200 that includes a growing stent 100 compressed on a balloon 260, the growing stent 100 may expand with the balloon 260 due to radial pressure from the balloon filling fluid. When fluid is removed from balloon 260, back pressure can return balloon 260 to its original compressed state, causing expanded growing stent 100 to remain separated from balloon 260 and balloon catheter. In one embodiment, the balloon catheter may have a handle at the proximal ends of the rods 240, 250 to connect the rods 240, 250, seal the lumen to prevent blood leakage, and/or provide an ergonomic grip for the operator. The handle can be made from hard plastic, soft silicone and/or other hard materials. An embodiment may also include an innermost lumen for passing a guidewire (not shown) into the vasculature. The guidewire may provide a guide to ensure that the balloon catheter reaches the target location 310 and can be inserted into the lumen of the delivery system.

In selected embodiments, delivery catheter 210 is advanced to target location 310 via the femoral vein or artery, depending on the endpoint. Other vessels 300 in the patient may be used to guide the delivery catheter 210 to the target location 310 properly.

Additionally and/or alternatively, the delivery catheter system 200 may optionally flush out air from the delivery catheter 210 before the delivery catheter 210 is inserted into the patient's body to prevent air molecules from entering the bloodstream, which can cause embolization and other problems in the vessel 300. Flushing air from the delivery catheter 210 may include, for example, purging air from the delivery catheter 210 with pressurized fluid. The delivery catheter system 200 may include a delivery catheter 210 and one or more internal lumens (not shown) located at least partially within the delivery catheter 210. The internal lumens may define at least one guidewire opening (not shown) and at least one hole connected to the balloon. Fluid may be injected into the internal lumens at the guidewire port, with at least a portion of the injected fluid exiting the internal lumens through the distal port to bleed air from the delivery catheter 210.

The dimensions of the delivered growing stent 100 can make the growing stent 100 safer for neonates and other younger patients. The growing stent 100, in one embodiment, can be delivered with an outer diameter of less than 2.5 mm when compressed, while allowing further expansion to an outer diameter of greater than 20 mm when fully expanded.

In the foregoing description, embodiments of an expanding stent 100 that are balloon-expandable are generally disclosed for illustrative purposes only and not for purposes of limitation. However, it should be understood that the catheter delivery system 200 shown and disclosed herein can be easily modified to deliver self-expanding growing stents, prosthetic heart valves, and/or other medical devices. In other words, delivery of self-expanding growing stents to the site of implantation can be performed percutaneously using modified embodiments of the delivery devices of the present invention. In general terms, an exemplary modified delivery device may include a transcatheter assembly (not shown) with a delivery sheath and/or additional sheaths as discussed above. The devices typically further include a delivery catheter, a balloon catheter, and/or a guidewire.

The current market for growing stents is not able to cover the full range required for the treatment of pathology throughout the life of the patient, especially in pediatric patients with congenital or anatomical diseases. In this case, the growing stent may initially be small enough to be safely delivered to the neonate, but may not grow to adult size. Conversely, a growing stent that expands to a size large enough to cause pathology in an adult cannot be compressed enough to be safely implanted on a catheter in a neonate, because neonatal vessels are much smaller than those of an adult.

Various congenital diseases can be defined as pathological narrowings such as tetralogy of Fallot, coarctation of the aorta, various atresias, and various stenoses.

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Claims (49)

Further understanding of the nature and advantages of the growing stent 100 will become apparent with reference to the remaining parts of the description and drawings. The variations and optional features noted above can be added to the growing stent 100 embodiments, either individually or in various combinations, depending on the situation. Specific numerical values for dimensions, shapes, diameters, cross-sections, or other geometric parameters are given here for illustration only and not for limitation. The disclosed embodiments are susceptible to various modifications and alternative forms, and specific examples thereof are shown by way of example in the drawings and are detailed herein. However, it should be understood that the disclosed embodiments are not to be limited to the specific forms or methods disclosed, but rather, the present invention is to cover all modifications, equivalents and alternatives. CLAIM 1. Catheterically inserted and re-expandable growing stent for implantation in a newborn patient, comprising an elongated stent frame (110) with a plurality of frame legs, each of which extends continuously from the proximal end region (130) of the specified stent frame to the distal end region (140) of said stent scaffold, wherein adjacent scaffold legs define intermediate scaffold cells (164) and intersect to form respective scaffold connections (170) whereby said elongated stent scaffold is expandable by a delivery catheter (210) from its original state to facilitate insertion by the delivery catheter into the selected lumen of the newborn patient to the first stable expanded state, configured to maintain the selected lumen during implantation, and the specified stent frame in the first expanded state defines an internal channel (120) with a first cross section, and specified said stent frame is configured to re-expand by subsequent insertion of the dilatation catheter from the first expanded state to the second stable expanded state as the patient grows, wherein said stent frame in the second expanded state continues to support the selected lumen and defines an internal channel with a second cross-section, greater than than the first cross section. 2. Growing stent according to claim 1, in which the initial state is less than 8 french (~2.67 mm) and/or the first cross section is less than 10 mm. 3. An expandable stent according to claim 1 or 2, wherein said stent frame is re-expandable to a second expanded state after the neonatal patient has grown to become a child. 4. Growing stent according to claim 3, in which the second cross section is from 8 to 15 mm inclusive. 5. An expanding stent according to any one of the preceding claims, wherein at least two of the scaffold struts have different strut widths. 6. Growing stent according to any one of the preceding claims, wherein the internal channel extends between the proximal and distal end regions of said stent body, wherein at least one of the end regions is widened radially outward to facilitate engagement between said stent body and the selected lumen, or widened radially inwards, or blunted to reduce the risk of aneurysm in the selected lumen. 7. An expanding stent according to any one of the preceding claims, wherein said stent scaffold comprises a fluid-tight coating to prevent leakage due to ingrowth of the selected lumen as the patient grows. 8. Growing stent according to any one of the preceding claims, wherein said elongate stent frame is made of stainless steel, cobalt-chromium, polymer, or combinations thereof. 9. A growing stent according to any one of the preceding claims, wherein the intermediate scaffold cells are surrounded by adjacent scaffold posts. 10. A growing stent according to claim 9, wherein two pairs of adjacent scaffold struts intersect to form one of the intermediate scaffold cells and form a plurality of strut connections. 11. An expanding stent according to any one of the preceding claims, wherein said stent scaffold is configured to further expand from a second expanded state to a third stable expanded state as the patient further grows, wherein said stent scaffold in the third stable expanded state continues to support the selected lumen and determines an internal channel with a third cross section larger than the second cross section. - 14 040514 12. The growing stent according to claim 11, wherein said stent scaffold is expandable to a third expanded state after the patient grows into an adult. 13. Growing stent according to claim 11 or 12, in which the third cross section is from 18 to 24 mm inclusive. 14. A method of implanting a catheter-introduced and re-expandable growing stent according to any one of claims 1-13 to a newborn patient, which includes introducing an elongated stent frame (110) into a selected lumen of a newborn patient by means of a delivery catheter (210), wherein the elongated stent frame is in its initial state to facilitate insertion and has a plurality of scaffold legs, each of which extends continuously from the proximal end region (130) of the stent frame to the distal end region (140) of the stent frame; and expanding the elongated stent frame by means of a delivery catheter from the initial state to the first stable expanded state to maintain the selected lumen, wherein adjacent frames of the frame define intermediate cells (164) of the frame and intersect to form the corresponding connections (170) of the racks, through which the elongated stent frame is expanded, moreover, the stent frame in the first expanded state defines an internal channel (120) with the first cross section, and the stent frame is re-expanded by subsequent insertion of the dilatation catheter from the first expanded state to the second stable expanded state as the patient grows, and the specified stent frame in the second expanded state continues to maintain the selected lumen and defines an internal channel with a second cross section larger than the first cross section. 15. The method of claim 14 wherein the elongated stent scaffold is inserted via a delivery catheter, the delivery catheter being a balloon catheter delivery system (260). 16. Catheterically inserted and re-expandable growing valve for implantation in a neonatal patient, comprising an elongated valve frame with a plurality of frame posts, each of which extends continuously from the proximal end region (130) of the specified valve frame to the distal end region (140) of the specified valve frame , wherein the adjacent scaffold posts define intermediate scaffold cells (164) and intersect to form respective post connections (170) whereby said elongated valve scaffold is expandable by the delivery catheter (210) from its initial state to facilitate insertion by the delivery catheter into the selected lumen a newborn patient to a first stable expanded state configured to maintain a selected implant lumen, wherein said valve frame in the first expanded state defines an internal channel (120) with a first cross section; and a plurality of leaflets (150) extending from said valve frame into the internal channel, wherein said valve frame is re-expandable by subsequent insertion of the dilatation catheter from the first expanded state to a second stable expanded state as the patient grows, wherein said valve frame in the second expanded state continues to maintain the selected lumen and defines an internal channel with a second cross section larger than the first cross section, and said leaflets provide valvular function in the first and second expanded states. 17. Growing valve according to claim 16, in which the initial state is less than 8 french (~2.67 mm) and/or the first cross section is less than 10 mm. 18. A growing valve according to claim 16 or 17, wherein said valve frame is configured to re-expand to a second expanded state after the neonatal patient has grown to become a child. 19. A growing valve according to claim 18, wherein the second cross section is between 8 mm and 15 mm inclusive. 20. A growing valve according to any one of claims 16-19, wherein the carcass studs have the same stud width. 21. A growing valve according to any one of claims 16-20, wherein the internal passage extends between the proximal and distal end regions of said valve body, wherein at least one of the end regions is widened radially outward to facilitate engagement between said valve body and the selected lumen, or widened radially inwards, or blunted to reduce the risk of aneurysm in the selected lumen. - 15 040514 22. A growing valve according to any one of claims 16-21, wherein said valve body comprises a fluid-impervious coating to prevent leakage due to the selected lumen growing in as the patient grows. 23. A growing valve according to any one of claims 16-22, wherein said elongated valve body is made of stainless steel, cobalt-chromium, polymer, or a combination thereof. 24. A growing flap according to any one of claims 16-23, wherein the intermediate frame cells are surrounded by adjacent frame posts. 25. A growing flap as claimed in claim 24, wherein two pairs of adjacent frame posts intersect to form one of the intermediate frame cells and form a plurality of post connections. 26. A growing valve according to any one of claims 16-25, wherein said valve frame is configured to further expand from the second expanded state to a third stable expanded state as the patient further grows, wherein said valve frame in the third stable expanded state continues to support the selected lumen and defines an internal channel with a third cross section larger than the second cross section. 27. A growing valve according to claim 26, wherein said valve frame is expandable to a third expanded state after the patient grows into an adult. 28. Growing valve according to claim 26 or 27, wherein the third cross section is between 18 and 24 mm inclusive. 29. A method of implanting a catheter-introduced and re-expandable growing valve according to any one of claims 16-28 to a neonatal patient, comprising introducing an elongated valve frame into a selected lumen of a newborn patient via a delivery catheter (210), wherein the elongated valve frame is in the original state to facilitate the introduction and has many racks of the frame, each of which extends continuously from the proximal end region (130) of the valve frame to the distal end region (140) of the valve frame; and expanding the elongated valve frame by means of the delivery catheter from the initial state to the first stable expanded state to maintain the selected lumen, wherein the adjacent frame posts define intermediate cells (164) of the frame and intersect to form respective posts connections (170), through which the elongated valve frame is expanded, moreover, the valve frame in the first expanded state defines an internal channel (120) with a first cross section, and a plurality of leaflets (150) are provided, passing from the specified valve frame into the internal channel, and the valve frame is re-expanded by subsequent insertion of the dilatation catheter from the first expanded state to a second stable expanded state as the patient grows, wherein the valve body in the second expanded state continues to support the selected lumen and defines an internal channel with a second cross section larger than the first cross section and the leaflets provide valvular function in the first and second expanded states. 30. The method of claim 29 wherein the elongated valve body is inserted via a delivery catheter, the delivery catheter being a balloon catheter delivery system (260). 31. Catheterically inserted and re-expandable growing stent for implantation in a newborn patient, comprising an elongated stent frame (110) with a plurality of frame posts, each of which extends continuously from the proximal end region (130) of the specified stent frame to the distal end region (140) said stent frame and has the same strut width, with adjacent struts of the skeleton defining intermediate cells (164) of the skeleton and intersecting to form respective strut connections (170) through which said elongated stent skeleton is expandable by means of a delivery catheter (210) from its initial state to facilitating insertion by means of a delivery catheter into a selected vessel of a newborn patient to a first stable expanded state configured to support the selected vessel upon implantation, wherein said stent frame in the first expanded state defines an internal channel (120) with a first cross section, wherein said stent frame is configured to re-expand by subsequent insertion of a dilatation catheter from a first expanded state to a second stable expanded state as the patient grows, wherein said stent frame in the second expanded state continues to support the selected vessel and defines an internal channel with a second transverse section larger than the first - 16 040514 cross section. 32. An expanding stent according to claim 31, wherein said stent scaffold initially has a small implant size to facilitate insertion into a neonatal patient. 33. Growing stent according to claim 32, in which the implantation size is less than 8 jackets (~2.67 mm). 34. Growing stent according to claim 32 or 33, wherein the first cross section is less than 10 mm. 35. An expanding stent according to any one of claims 31-34, wherein said stent frame is re-expandable to a second expanded state after the neonatal patient has grown to become a child. 36. The growing stent according to claim 35, wherein the second cross section is between 10 mm and 15 mm inclusive. 37. A growing stent according to any one of claims 31-36, wherein said stent frame is configured to further expand from a second expanded state to a third stable expanded state as the patient further grows, wherein said stent frame in the third expanded state continues to support the selected vessel and defines an inner channel with a third cross section larger than the second cross section. 38. The growing stent of claim 37, wherein said stent scaffold is expandable to a third expanded state after the patient grows into an adult. 39. An expanding stent according to claim 37 or 38, wherein the third cross section is between 18 mm and 24 mm inclusive. 40. An expanding stent according to any one of claims 31-39, wherein said stent scaffold is tubular in shape. 41. A growing stent according to any one of claims 31-40, wherein the strut connection between the selected struts of the scaffold has a junction width that is small enough to facilitate insertion of said stent carcass in its original state and that is large enough to support expansion of said stent carcass to the first and the second expanded state while maintaining strength to maintain the selected lumen. 42. A growing stent according to any one of claims 31-41, wherein the internal channel extends between opposite end regions of said stent body, at least one of the end regions is widened radially outward to facilitate engagement between said stent body and the selected vessel. 43. A growing stent according to any one of claims 31-42, wherein the internal channel extends between opposite end regions of said stent frame, wherein at least one of the end regions is radially inwardly broadened or blunted to reduce the risk of aneurysm in the selected vessel. 44. A growing stent according to any one of claims 31-43, comprising a fluid-tight coating to prevent leaks due to ingrowth of the selected vessel as the patient grows. 45. A growing stent according to any one of claims 31-44, wherein said elongated stent frame is made of stainless steel, cobalt-chromium, polymer, or a combination thereof. 46. A growing flap according to any one of claims 31-45, wherein the intermediate frame cells are surrounded by adjacent frame posts. 47. A growing stent according to any one of claims 31-46, wherein two selected pairs of adjacent scaffold struts intersect to form one of the intermediate scaffold cells and form a plurality of strut connections. 48. A growing stent according to any one of claims 31-47, wherein two pairs of adjacent scaffold struts intersect to form one of the intermediate scaffold cells and to form a plurality of strut connections. 49. Catheterically inserted and re-expandable growing stent for implantation in a newborn patient, comprising an elongated stent frame (110) with a plurality of frame posts, each of which extends continuously from the proximal end region (130) of the specified stent frame to the distal end region (140) said stent frame and has the same strut width, with adjacent struts of the skeleton defining intermediate cells (164) of the skeleton and intersecting to form respective strut connections (170) through which said elongated stent skeleton is expandable by means of a delivery catheter (210) from its initial state to facilitating insertion by means of a delivery catheter into a selected vessel of a newborn patient to a first stable expanded state configured to support the selected vessel upon implantation, wherein said stent frame in the first expanded state defines an internal channel (120) with a first cross section, wherein said stent frame is configured to re-expand by subsequent insertion of a dilatation catheter from a first expanded state to a second stable expanded state as the patient grows to a teenage patient, -