Delayed memory device

SWEDEN <₁₂) PATENT WRITING

03) C2 (id 524 709)

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(19) SE ₍₅₁₎

International class ⁷

A61F 2/02, A61L 27/40, 27/58

PATENT AND REGISTRATION (45) (41) (22) (24) (62) (86) (86) (83)

Patent filed Application widely available The patent application was submitted on expiration date

Application number International filing date

Filing date for European patent application Deposit of microorganism

2004-09-21

2003-09-10

2002-01-11

2002-01-11 (21) Patent Application Number 0200073'5

Application received as:

Swedish patent application completed international patent application with number □ converted European patent application with number (30) Priority information (73) (72) (74) (54) (56) (57)

PATENT OWNER Edwards Lifesciences AG, Au Glapin 1162 Saint-Prex CH INVENTOR Jan Otto Solem, Stetten CH, Per Ola Kimblad, Lund SE OMBUD AWAPÄTENT AB

NAME Device for delayed reshaping of a heart vessel and a heart valve

CALLED PUBLICATIONS:

WO A2 185 061 (A61L 15/28), WO Al 041 649 (A61F 2/02),

WO Al 154 618 (A61F 2/02), WO Al 100 111 (A61F 2/06)

SUMMARY: A medical device and method for providing a shape change in part of the body of an organism. The device is insertable into the body of the organism and comprises an element (1; 3; 5; 7; 9; 11; 14; 16; 20;

28) having a preferred mold state and a tendency to transfer its mold to said preferred mold state when in a non-preferred mold state. The device further comprises a resorbable member (2; 4; 6; 8, 10; 12; 13; 15; 18; 19; 21; 29) which is arranged to hold the element (1; 3; 5; 7; 9; 11; 14; 16; 20; 28) in the non-preferred mold state and to delay transmission when the device is inserted into the body of the organism by counteracting said transfer during resorption of the resorbable member (2; 4; 6; 8, 10; 12; 13 ; 15; 18; 19; 21; 29) of the surrounding body of the organism.

The device and method can be used, for example, for the treatment of mitral ring dilation and in particular for reducing the circumference of the mitral ring. The device and method can further be used for the treatment of pathological heart growth, for the treatment of pulmonary bladder growth and for the treatment of bladder emphysema.

IN

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: I-5

The numbers in brackets indicate international identification code, INID code. Letters in clamps indicate international document code.

524 709 • ·« ····

SUMMARY

A medical device and method for providing a shape change in part of the body of an organism. The device is insertable into the body of the organism and comprises an element (1; 3; 5; 7; 9; 11; 14; 16; 20;

28) having a preferred mold state and a tendency to transfer its mold to said preferred mold state when in a non-preferred mold state. The device further comprises a resorbable member (2; 4; 6; 8, 10; 12; 13; 15; 18; 19; 21; 29) which is arranged to hold the element (1; 3; 5; 7; 9; 11; 14; 16; 20; 28) in the non-preferred mold state and to delay transmission when the device is inserted into the body of the organism by counteracting said transfer during resorption of the resorbable member (2; 4; 6; 8, 10; 12; 13 ; 15; 18; 19; 21; 29) of the surrounding body of the organism.

The device and method can be used, for example, for the treatment of mitral ring dilation and in particular for reducing the circumference of the mitral ring. The device and method can further be used for the treatment of pathological heart growth, for the treatment of pulmonary bladder growth and for the treatment of bladder emphysema.

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Technical field of the invention

The present invention relates to a medical device for reshaping a heart vessel and a heart valve.

Background of the invention

At present, the treatment of mitral ring dilation and other deficiencies in the closure capability of the mitral valve consists of either repair or replacement of the mitral valve device. Both methods require open heart surgery, with the use of total cardiopulmonary bypass, cross-clamping of the aorta and heartbeat. For some groups of patients, open heart surgery is particularly risky and therefore a less invasive method of repairing deficiencies in the capability of the mitral valve is desired.

Such a less invasive method is proposed in US 6,210,432, which describes a method for treating deficiencies in the closure capability of the mitral valve without the need for cardiopulmonary bypass and opening of the chest and heart. The method uses a device comprising an elongated body having dimensions such that it is insertable into the large cardiac vein, which is a vein that essentially surrounds the mitral orifice and mitral ring and drains blood from the heart muscle to the right atrium. The elongated body has two states, wherein in a first state the elongated body has a shape which is adaptable to the shape of the large cardiac vein, and to the second state in which the elongated body is transferable from said first state by adopting a reduced radius of curvature. . Accordingly, the radius of curvature of the large heart vein is 524 709 reduced. Since the large heart vein surrounds the mitral ring, the radius of curvature as well as the circumference of the mitral ring is reduced. Thus, the described method takes advantage of the position of the large cardiac vein close to the mitral ring, which makes repair possible by using existing catheter-controlled techniques.

According to a method described in US 6 210 432, a device comprising an elongated stent is used. The elongated stent includes hooks arranged to dig into the walls of the large heart vein by having the surgeon retract a covering envelope from the stent, in order to fix the stent's position in the large heart vein. A stabilizing instrument is used to hold the elongated stent in its first state and then, after the hooks have engraved into the walls, release it to its second state assuming a reduced radius of curvature. However, position fixing of the elongated stent in the large heart vein by means of the hooks may be insufficient so that the sudden release of contraction of the elongated stent dislocates it. This dislocation of the device may result in unsatisfactory reduction of the circumference of the mitral ring.

According to an alternative method described in US 6,210,432, the device comprises three stent sections positioned in the large heart vein and connected by wires. The wires can be operated from the outside of the vein system so that the distances between the adjacent stent sections are reduced. Also with this method, there is a risk of dislocation of the device, since the accidental surgeon can move insufficiently fixed stent sections out of the correct position as the surgeon manipulates them from the outside of the vein system.

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Summary of the Invention

It is an object of the present invention to provide a more secure fixation of a medical device for reshaping a body vessel.

This and other objects are accomplished by means of a device as defined in claim 1.

More specifically, according to the present invention, a medical device for reshaping a heart valve is elongated and has dimensions such that it is insertable into a heart vessel and has two states, a first condition in which the device has a shape which is adaptable to the shape of the vessel and a second state in which the device is transferable from said first state. The device according to the invention comprises a fixing means for fixing the ends of the device inside the vessel when the device is first placed therein, a shape-changing element for transferring the device to the second state by reshaping it, and a delay means for delaying said transformation until the ends of the device have strengthened, wherein said delaying means delays said transformation by retaining said device in said first state until the delaying means is resorbed.

By allowing the ends of the device to heal into the walls of the vessel, e.g., the large heart vein, by means of said fixing means, before said reshaping of the device, the present invention provides a more secure fixation of a device for reshaping a body vessel. Thus, the normal healing process that occurs in each living organism is allowed to provide a well-established fixation of the device.

A resorbable material is such a material that when introduced into the body of an organism it will be resorbed by the body through enzymatic processes and also by active absorption of the cells into the blood and tissue cells in the body. Thus comes the resorbable

524 709 the material of the delay means to advantageously decompose and disappear from the device over time, without leaving any major residual products in the body.

Preferably, said resorbable means comprises a resorbable case arranged to surround said shape-changing element. This is advantageous because with the shape of a case, the resorbable member is both easy to manufacture and easy to attach to the element.

In another preferred embodiment of the invention, said fixing means is arranged to expand against the wall of the vessel when first placed therein. This expansion against the vessel wall initiates and contributes to the fixation of the ends of the device, thereby enabling a fixed fixation.

In yet another preferred embodiment of the invention, said fixing means is arranged to grow into the wall of the vessel, thereby reinforcing said fixing of the ends of the device. By taking advantage of the healing process in the tissue of the vessel wall, the fixing means can be fixed effectively. This can be facilitated by an expansion against the vessel wall as mentioned above.

In a preferred embodiment, said fixing means comprises a self-expandable stent at each end of the device.

According to another preferred embodiment, said shape-changing element comprises a shape memory material which provides said reshaping of the device. A shape memory material is one that has two different shapes, one at lower temperatures and another at higher temperatures. At the lower temperatures, for example below 30 ° C, the material is elastic and can be introduced into the body. At the higher temperatures, the material is still elastic but also becomes super elastic and assumes its preferred original shape unless the transformation to this original shape is prevented by external loading on the material. When the material is super elastic, it can be deformed and deformed

524 709, the material will use its super-elastic forces to return to its preferred shape. The use of a shape memory material in the element is advantageous, inter alia, since it can then easily be provided with said delay means while the element, at a lower temperature outside the body, assumes a shape corresponding to a non-preferred shape state within the body.

In one embodiment, said shape-changing element comprises Nitinol which provides said reshaping of the device.

Preferably, said reshaping of said device comprises shortening said device.

In another preferred embodiment, said device is used to treat mitral dilation. Since the device can be inserted into a blood vessel using catheter-controlled techniques, the use of this device for treating mitral dilation is advantageous over open heart surgery, which is currently the procedure used for repair or replacement of the mitral valve apparatus.

In yet another preferred embodiment, said vessel is the large cardiac vein. The big heart vein surrounds the mitral orifice and the mitral ring. Therefore, reshaping this vein also has a compressive effect on the mitral ring.

Preferably, said reshaping of said device is used to reduce the curvature radius of the large heart vein. Thus, the radius of curvature as well as the circumference of the mitral ring is also reduced.

It should be understood that many modifications are possible within the spirit and scope of the invention, which are limited only by the appended claims.

Brief description of the drawings

The invention will now be described in more detail with reference to the accompanying drawings, in which:

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Figures 1-4 are schematic views of the structure and function of an embodiment of a deformation device illustrating the principle of delayed shortening;

Figures 5-8 are schematic views of the structure and function of another embodiment of a deformation device illustrating the principle of delayed elongation;

Fig. 9 is a schematic view of another embodiment of a deformation device which is an alternative to the embodiment shown in Fig. 7;

Figures 10 and 11 schematically illustrate another embodiment of a deformation device shown in a first state and a second abbreviated state, respectively;

Figures 12 and 13 schematically illustrate another embodiment of a deformation device shown in a first state and a second extended state, respectively;

Fig. 14 is a schematic view of yet another embodiment of a deformation device shown in a first state;

Fig. 15a is a schematic view of another embodiment of a deformation device which is an alternative to the embodiment shown in Fig. 14 and shown in a first state;

Fig. 15b is a schematic view of a shape change device of Fig. 15a, illustrating the structure of a portion of the shape change device;

Fig. 16 is a schematic view illustrating the second state of a shape change device of Fig. 14 or 15b;

Figures 17 and 18 are schematic views illustrating another embodiment of a deformation device shown in a first state and a second state, respectively;

Fig. 19 is a schematic perspective view of a shape-changing device for two-dimensional contraction;

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Fig. 20 is a schematic perspective view of another shape-changing device for two-dimensional contraction;

Figures 21 and 22 illustrate schematically an embodiment of a device for treating mitral ring dilation, shown in a first state and a second abbreviated state, respectively;

Figures 23, 24 and 25 are schematic views illustrating the positioning, fixing and shortening of a device according to Figure 21 used in the large cardiac vein;

Fig. 26 is a schematic perspective view illustrating part of a possible configuration of a deformation device having a reshapable surface;

Figures 27-30 are schematic views illustrating the positioning and contraction of one embodiment of the deformity device for the treatment of pathological cardiac growth;

Figures 31 and 32 are schematic views illustrating the positioning of one embodiment of the deformity device for the treatment of chronic, obstructive pulmonary disease.

Detailed description of preferred embodiments

Figures 1 to 4 show the principle of delayed shortening according to the invention.

In Figure 1, there is shown a shape-changing element 1, here in the form of a thread 1, made of or at least comprising a shape memory material, which element has a curved shape. This shape is the original shape that the shape-changing element 1 remembers and will assume when its temperature passes a certain limit value, for example, exceeds 30 ° C.

Fig. 2 shows the shape-changing element 1 according to Fig. 1 as it has been extended by extension to a substantially straight shape.

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Fig. 3 illustrates an embodiment of a deformation device where the device is in its unactivated mold state A. More specifically, by surrounding the extended and straight shape changing element 1 of Figure 2 with a delay means 2, here in the form of a tube 2 having a sufficiently small internal cross-section, the extended shape of the shape changing element 1 can be maintained even when the device is thus implanted in a human body and the temperature of the shape-changing element 1 thus exceeds the limit value, for example 30 ° C.

The delay means 2 may be flexible enough to follow the bends in, for example, vessels, but has a stiffness, here in particular in its radial direction, which resists the shape-changing force of the shape-changing element 1.

Thus, when the shape-changing element 1 of the device is implanted in the human body, it will strive towards its original, here curved, shape according to Figure 1, but is hindered by the delay means 2.

However, by the delay means 2 being made of a resorbable material, the delay means 2 will be resorbed over time and the shape-changing element 1 will regain its original shape when the delay element 2 has been resorbed to such a degree or extent that it can no longer hinder the shape-changing element 1; which is schematically illustrated in Figure 4. Thus, the device has now been transformed from its non-activated long form state A (Fig. 3) to

-------- one-actuated, shortened mold state A '...... (Fig. 4), ..... in ......-.......... ..

the device consisting essentially of only the shape-changing element 1.

The shape change device of Fig. 3 can be manufactured as follows. The wire 1 of a shape memory material, for example, with the shape illustrated in Figure 2, is programmed to remember the shape illustrated in Figure 1 by being held in that state while being heated to a temperature above said limit value. When cooling the wire 1 down below the threshold temperature, for example

524 709 down to room temperature, the wire 1 will assume its former shape as shown in Fig. 2. In this cold state, the wire 1 is covered with the resorbable tube 2, for example, by the tube 2 being threaded on the wire 1 or by forming the tube 2 around the wire. 1st

Other embodiments of a deformation device may operate and may be manufactured in a similar manner. Thus, a shape-changing element is first held by a memory material in a preferred shape state while being heated above a threshold temperature, and then cooled below the threshold temperature to regain its former non-preferred shape state. Thereafter, the now programmed shape-changing element is locked in said non-preferred shape state by means of a delay means such that the delay element will prevent the shape-changing element from regaining its preferred shape state when heated again, for example in a human body.

Reference is now made to Fig. 3. The inner radius of the tube 2 need not necessarily be so small that the shape-changing element in the form of the wire 1 cannot move in the radial direction at all. Thus, there may be a small, radial clearance in which the shape-changing element 1 can move without being able to change the length of the device to any great extent. However, the shape change device of Figure 3 can also be manufactured with substantially no clearance between the shape changing element 1 and the inside of the delay means 2, possibly also with a bias or bias force from the delay means 2 acting on the shape changing element 1.

In order to clearly illustrate the shortening of the shape change device, the curved wire 1 is located to the left of Fig. 4, but, after its transformation, the wire 1 may as well be located elsewhere along the remaining portions of the tube 2.

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Figures 5 to 8 show the principle of delayed extension.

Fig. 5 shows a shape-changing element 3, here in the form of a thread 3 of a shape memory material having a straight, original shape.

Fig. 6 shows the shape-changing wire element 3 of Fig. 5 when it has been folded into a curved shape.

Fig. 7 illustrates an embodiment of a deformation device comprising a thread as illustrated in Fig. 6, which illustrates the device in its non-activated deforming state B. By overlaying the curved, deforming element 3 with a delay means 4 in the form of a tube 4 of a resorbable material, the curved form B can be retained even when the device is implanted in a human body and strives for its original straight shape.

As illustrated schematically in FIG. 8, after implantation into the human body, the delay means 4 is resorbed over time and, consequently, the shape-changing element 3 will be released freely to assume its original straight shape B '. Thus, the shape change device has now been transformed from its unactivated, short shape state B (Figure 7) to an activated, extended shape state B '(Figure 8).

In the illustrated embodiments, the length of the shape-changing element 1; 3 is substantially unchanged by the transformation, while the shape of the shape-changing element 1; 3 is changed so that the length of the shape-changing device is changed.

According to the invention, the material from which the shape-changing element is formed may consist of or at least include Nitinol, which is an alloy consisting of nickel (54-60%) and titanium. Small traces of chromium, cobalt, magnesium and iron can also be found in Nitinol. Alternatively, other materials such as shape memory polymers (Shape Memory Polymers, SMP) can be used as shape memory materials.

In fact, as far as the present invention is concerned, the shape-changing material need not be a shape-memory material. Any super-elastic material would work in most applications.

Examples of useful, resorbable materials from which the delay means can be made, or at least include, are PDS (polydioxanone), Pronova (polyhexafluoropropylene VDF), Maxon (polyglyconate), Dexone (PGA, polyglycolic acid), Vicryl (polytglycine), PLA , PDLLA (polydexo lactic acid), PLLA (pololevo lactic acid), starch, various forms of sugar, butyric acid, collagen and collagen vapor. Depending on the choice of material, the release of the shape-changing forces can be delayed for a desired period of time. Also, design parameters such as the thickness of the resorbable material can be set so that the shape-changing forces are delayed as long as desired. The delay time can vary from, for example, a few days up to several years depending on the application.

The thickness of the delay means may vary along the device so that the order in which different parts of the device are released by the delay means can be controlled.

Figures 9 to 20 show some different embodiments of a shape change device.

Fig. 9 shows an embodiment of a deforming device which is an alternative embodiment of a delayed extension device as compared to the device shown in Fig. 7. Instead of a resorbable tube 4 as in Fig. 7, the resorbable member comprises resorbable cross-links 6 which hold the deformable element. 5 in its curved mold state and thus the device in its non-activated, short mold state C.

Resorbable cross-links 6 (Fig. 9) can also be combined with a tube 4 (Fig. 7).

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Fig. 10 shows an embodiment of a shape change device in its non-activated, extended shape state

D. Here, the shape-changing element 7 is scissor-shaped. A delay member 8 in the form of a tube 8 of resorbable material holds the shape-changing element 7 in an extended, extended shape state, and, thus, also the device in its extended shape state D. When the delay means 8 has been sufficiently resorbed, the scissor-shaped shape-changing element 7 will regain its original, non-extended shape and the device is transformed into its activated, short shape state D '(Fig. 11).

Fig. 12 shows an embodiment of a shape change device in its non-activated short shape state E. A scissor shaped, shape changing element 9 of the device is held in a short shape state by means of a delay means in the form of a resorbable wire 10, and, thus, the whole the device in its short form state

E. When the delay member 10 is cut off due to resorption, the shape-changing element 9 will regain its original, extended shape so that the device is transformed to its activated shape state E ', (Fig. 13).

Fig. 14 shows an embodiment of a shape change device comprising a shape changing element in the form of a coil 11 of a shape memory material which has been extended and placed in a delay means in the form of a tube 12 of resorbable material. The device is then in its non-activated mold state F. When the delay means 12 has been sufficiently resorbed, the shape-changing element 11 will regain its original, shorter and wider shape as shown in Fig. 16, and the device is transformed to its activated shape state F '.

In an alternative embodiment shown in Figs. 15a and 15b of a deformation device, the tube 12 in Fig. 14 has been replaced with a resorbable rod 13 provided with notches.

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13a in which a coil 11 is initially wound. The winding of the coil 11 in the grooves 13a prevents the coil 11 from regaining its original shape (Fig. 16) and thus the device is held in its non-activated mold state G by the rod 13, as illustrated in Fig. 15a. By resorption of the rod 13 in, for example, a human body, the shape-changing force of the coil 11 is released and the device is transformed to its activated shape state G 'as shown in Figure 16.

In another embodiment shown in Figure 17 of a deformation device, a coil 14 is wound around a resorbable rod 15. When the rod 15 is resorbed, the shape-changing forces of the coil 14 will be released so that the coil 14 regains an original, extended shape, as shown in FIG. 18, whereby the device is transformed from its non-activated mold state H to its activated mold state H '.

Fig. 19 shows an embodiment of a shape change device in the form of a patch for closing or closing openings, for example in the heart of a human or animal body. The patch has a shape changing element 16 comprising a grid matrix formed of threads made of memory material such as Nitinol or SMP. The wires can be individually lined with biocompatible material such as PTFE or dacron so that the spaces between the wires are filled, for example, as shown in Fig. 26 with wires 28 and biocompatible material 29.

........ The patch of Fig. 19 further comprises a rarTTTör = = anchoring of the patch in the body, for example by means of sewing threads. The frame may be made of some biocompatible material, such as PTFE or dacron. By using a cone (not shown), the threads can be disassembled, creating a central opening 16a in the patch. The cone is advanced until a delay means 18 in the form of a separate ring 18 of a resorbable material, initially placed on the cone, is located in the opening 16a. The cone is then retracted and the ring 18 is left in the opening 16a and obstructed

524 709 the elastic threads in such a way that the central opening 16a of the patch is maintained. Fig. 19 shows the patch in its non-activated mold state I with the ring 18 placed centrally. After implantation and sufficient resorption of the obstructing ring 18 and after a specified period of time, the central opening in the patch is closed and the patch is activated.

Fig. 20 shows an alternative embodiment of a shape change device in the form of a patch for closing openings. The patch can be constructed by attaching delay means 19 in the form of resorbable threads or straps 19 on top of a sharp cone and down the sides of the cone, feeding the cone through the middle of the patch so that the elastic threads 16 are spread and an opening 16a in the patch thereof. is created, and attaching one end of each band in the frame 17 to one of the sides of the patch and the other end of each band 19 to the frame 17 on the other side of the patch so that each band 19 runs through the opening. The straps 19 could be positioned at regular intervals along the circumference of the aperture to open up a substantially circular hole in the center of the patch. By means of the resorbable straps 19, the patch is kept in its non-activated mold state J.

It should be noted that the various embodiments described above are merely examples. There are many possible, different forms for a deformation device. For example, the single, shape-changing thread in Figs. 1 to 11-9 can be replaced with multiple threads or = with e11 or ..............

several bands. The scissor-shaped elements 7 and 9 in Figs. 10 to 13 can be multiplied to form a scissor-shaped surface, which in turn can be formed in various shapes. The simple tube of Figures 3, 7, 10 and 14 may be slit or divided into several tube segments. The number of possible embodiments of a deformation device is, in fact, infinitely large.

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Next, an embodiment according to the invention of a device for treating mitral ring dilation will be described.

The device shown in Fig. 21, which is in an extended and non-activated mold state K, comprises a shape-changing element 20 in the form of a shape memory metal wire 20, a delay means 21 in the form of a resorbable case 21 surrounding the shape memory metal wire 20 for holding it in a straightened mold state, and self-expandable stents 22 and 23 located at opposite ends of the device.

The device may include one or more additional shape memory metal wires, for example, if a stronger, shortening force is desired.

The shape memory metal wire 20 may be made of Nitinol, or other similar material having a memory of an original shape as illustrated in Figure 22 and may be temporarily forced into another shape, for example, as illustrated in Figure 21.

The resorbable case 21 is made of PDS, but it can also be made of any other material that is resorbable by the surrounding blood and tissue when applied to a human body and has the stability and flexural properties required. The thickness of the resorbable case 21 is selected so that the time required for the surrounding blood and tissue of the large cardiac vein 24 to resorb the resorbable case 21 sufficiently for the device to enter its second, shorter form state K 'is adapted to the time required for the ends of the device to be fixed in the large cardiac vein 24.

The self-expandable stents 22 and 23 may be of conventional type with an elastic cylindrical assembly made of, for example, nitinol, in an open zigzag configuration, and a cylindrical elastic film having a diameter substantially the same as that of the elastic assemblies.

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The device described above, which is seen in Fig. 21, is placed in the large cardiac vein 24, shown in Figs. 23 to 25, as follows:

An insertion tube (not shown) of synthetic material can be used to provide access to the vein system. Once the vein system has been accessed, a long metal guide wire (not shown) is passed through the insertion tube and via the vein system to the large cardiac vein 24. This guide wire is provided with X-ray spacing markers so that the position of the guidewire in the large cardiac vein 24 can be monitored.

The elongated device of Fig. 21 is locked on a stent insertion device (not shown) so that the self-expandable stents 22 and 23 are kept in a non-expanded state. Thereafter, the stent insertion device with the elongate device loosely thereafter is pushed through the insertion tube and the venous system to the large cardiac vein 24 supported on the guide wire. Having obtained an exact positioning for the elongated device in the large heart vein 24, as illustrated in Figure 23, where the mitral valve ring 25 and the mitral valve 26 with a central opening 27 are shown, the stent insertion device is removed, whereby the self-expandable stents 22 and 23 will expand toward the inner wall of the large heart vein 24 and provide a temporary fixation of the elongate device in the large heart vein 24. Then the guide wire and insertion tube are removed, the insertion hole is sewn together and the operation is completed.

After the operation, the self-expandable stents 22 and 23 will grow into the wall of the large cardiac vein 24, at the same time as the resorbable case 21 will be resorbed by the surrounding blood and tissue of the large cardiac vein 24, as illustrated schematically in Fig. 24. When the resorbable case 21 has been resorbed to such an extent that it can no longer hold the shape memory metal wire 20 in its straightened shape state, the self-expandable stents 22 and 23 will be in a fixed state, i.e. be properly fixed in the

524 709 large heart vein 24 wall. Then, the shape memory metal wire 20 is pulled together and the device is transformed into its activated, shorter shape state K ', as illustrated in Figs. 22 and 25. This shortening of the device causes it to bend toward the mitral flap ring 25, moving its rear portion forward. This movement reduces the circumference of the mitral valve ring 25 and thereby closes the central opening 27.

The device may be positioned by catheter technique or by any other suitable technique. It may be designed or heparin coated to avoid thrombosis of the large cardiac vein 24, thereby reducing the need for aspirin, ticlopedin, or coagulation inhibitory therapy.

Fig. 26 shows a possible embodiment of a part of a collapsible surface. The collapsible surface comprises a shape changing element in the form of a grid of molded memory metal wires 28 covered by a retention means in the form of a web of a resorbable material (note that Fig. 26 was previously used to illustrate how the threads of the patches of 19 and 20 can be coated with biocompatible material). The fabric includes resorbable strips 29 which have been woven together to form a surface. Each of the resorbable straps 29 is solid as in a cylindrical cavity in which a thread 28 is located, just as the thread 1 is located within the tube 2 in Fig. 3.

The straps 29 prevent the threads 28 from folding together to their original curved shapes as long as the fabric 29 is not resorbed.

Analogous to the shape change device of Fig. 3, there may be a radial clearance between the inner wall of each strip 29 and the wire 28 located inside the tape, in which clearance the wire 28 can move without being able to change the size of the surface of the device to any great extent.

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Furthermore, the cavity of each strip 29 need not necessarily be cylindrical. In fact, if the width of each band 29 is sufficiently small compared to the bends that the wires 28 will assume when activated as a result of the bands 29 being resorbed, the bands 29 may be hollow.

The collapsible surface of Fig. 26 can be made by threading a thread 28 of memory material into each resorbable band 29, and the strips 29 of threads 28 are woven together to form the web illustrated in Fig. 26.

Another possible way of making a collapsible surface would be to arrange threads or strips of a memory material in a grid matrix and to fix the threads or strips together by resorbable cross-links. The resorbable cross-links would then prevent the wires or ribbons from folding together as long as enough of the resorbable material in the cross-link is left unresorbed.

A collapsible surface, such as the recently mentioned one or as shown in Fig. 26, can be formed into a collapsible bag as shown in Figs. 27 to 30, which can be used to support a body member or to prevent a pathologically growing body member.

Figures 27 to 30 illustrate the use of a retractable sac 30 for the treatment of pathological heart growth.

Reference is made to Fig. 27. The sack 30 in its non-activated mold state L is ejected and inserted on a catheter with an anchoring member 32, here in the form of a suction cup 32, and the catheter 31 with the sack 30 is inserted into the cardiac tip 33a of the heart 33 in known manner. .

Reference is now made to Fig. 28. The suction cup 32 is placed on the heart tip 33a and the bag 30 is inserted by the catheter 31, using a catheter instrument (not shown), over the suction cup and up over the heart 33.

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Reference is now made to Fig. 29. When the sack 30 is positioned around the heart 33, the suction cup 32 is pulled out through the bottom of the sack 30 and the catheter 31 is removed from the body.

After a period of time, the resorbable material of the sack 30 will be resorbed and an inhibitory force of the shape memory metal wires towards the heart 33 is released, thus transforming the sack 30 into its activated mold state L ', as illustrated in Figure 30.

The sack 30 will then press itself tightly around the heart 33 and apply a continuous, inhibitory force to the heart 33, thereby preventing the heart 33 from growing further.

A collapsible surface can also be used as a collapsible sheet for treating, for example, lung bladder growth.

Figures 31 and 32 illustrate the use of one embodiment of a deformity device for treating lung bladder growth.

Reference is made to Fig. 31. A retractable blade 34 in its non-activated mold state M is rolled up on a catheter 35 and inserted between the ribs 36 via the sinus pleurae to the space between the pleural polmonalis and the pleural parietalis of the lung 38.

Reference is now made to Fig. 32. The blade 34 is then rolled out over the lung 38 and the catheter 35 is removed.

The ends of the blade 34 are arranged to grow firmly on the pleural pulmonary artery so that subsequent contraction of the blade 34, as a result of resorbable material of the blade 34, causes the blade 34 to compress the lung 38 by a force of the shape memory metal wires in the blade 34 Thus, pathological growth of lung bladder sacs is prevented.

In this embodiment, the retractable blade 34 is contracted in two directions, one substantially vertical and one substantially horizontal. The blade 34 could also be arranged to contract in only one direction.

524 709, for example, the most horizontal, and yet prevent lung bladder sacs from growing.

It should be appreciated that modifications to the above-described devices and methods can be made by those skilled in the art without departing from the spirit and scope of the invention.

524 709

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