Delayed memory device
A medical device and a method for providing a change of shape in a part of the body of an organism. The device is insertable into the body of the organism and comprises a member having a preferred state of shape and having a tendency to transfer its shape towards said preferred state of shape when being in a non-preferred state of shape. The device further comprises a resorbable means which is arranged to hold the member in the non-preferred state of shape and to delay the transfer when the device is inserted into the body of the organism by counteracting said transfer during resorption of the resorbable means by the surrounding body of the organism.
1. A medical device for reshaping a mitral valve annulus in a body, comprising:
a shape-changing member having proximal and distal ends and biased to move from a first stretched configuration to a second configuration that is bent and shortened;
a proximal self-expandable stent attached to the proximal end of the shape-changing member along a circumferential portion of the proximal stent and a distal self-expandable stent attached to the distal end of the shape-changing member along a circumferential portion of the distal stent, the proximal and distal self-expandable stents configured for anchoring the proximal and distal ends of the shape-changing member within a coronary sinus; and
a resorbable material disposed along the shape-changing member, the resorbable material configured to maintain the shape-changing member in the first stretched configuration;
wherein, in the second configuration, the shape-changing member is configured to apply sufficient force to the coronary sinus to reshape the mitral valve annulus;
wherein the resorbable material has a design parameter to delay the bending and shortening to the second configuration until after expanded portions of the proximal and distal stents have sufficiently grown into an inner wall of the coronary sinus to support the bending and shortening to the second configuration.
2. The medical device of claim 1 , wherein the shape-changing member is made of an elastic material.
3. The medical device of claim 1 , wherein the shape-changing member is made of a material having superelastic properties.
4. The medical device of claim 1 , wherein the shape-changing member is made of a shape memory material.
5. The medical device of claim 1 , wherein the shape-changing member is made of a shape memory metal.
6. The medical device of claim 5 , wherein the shape memory metal is Nitinol.
7. The medical device of claim 1 , wherein the shape-changing member is made of a shape memory polymer.
8. A medical device for reshaping a mitral valve annulus in a body, comprising:
a shape-changing member made of a shape memory material, the shape-changing member having proximal and distal ends and biased to move from a first configuration to a bent second configuration having a different shape than the first configuration;
a proximal anchor fixed to the proximal end of the shape-changing member and a distal anchor fixed to the distal end of the shape-changing member, the proximal and distal anchors being expandable to engage an inner wall of a coronary sinus at a location adjacent the mitral valve annulus and at an opposed location on a posterior side of the inner wall of the coronary sinus; and
a resorbable material disposed along the shape-changing member, the resorbable material configured to maintain the shape-changing member in the first stretched configuration;
wherein, in the second configuration, the shape-changing member is configured to apply sufficient force to the coronary sinus to reshape the mitral valve annulus;
wherein the resorbable material has a design parameter to delay the bending of the shape-changing member to the second configuration until after the proximal and distal anchors have been expanded to engage the inner wall of the coronary sinus and have sufficiently grown into the inner wall of the coronary sinus to support the bending to the second configuration; and
wherein the shape-changing member comprises a scissor-shaped member having shaped memory material and the resorbable material is a thread located inside openings of the scissor-shaped member.
9. The medical device of claim 8 , wherein the proximal and distal anchors each comprises a self-expandable cylindrical stent.
10. The medical device of claim 8 wherein the proximal anchor comprises:
a proximal stent fixed to the proximal end of the shape-changing member and the distal anchor comprises a distal stent fixed to the distal end of the shape-changing member.
11. The medical device of claim 8 , wherein at least a portion of the device contains a vascular endothelial growth factor.
12. The medical device of claim 8 , wherein the resorbable material comprises a thread disposed along the shape-changing member.
13. The medical device of claim 8 , wherein the resorbable material comprises a sheath dispose over the shape-changing member, the sheath being located between the proximal and distal anchors such that the anchors may expand before the sheath is resorbed.
14. A medical device for reshaping a mitral valve annulus in a body, comprising:
a shape-changing member having proximal and distal ends and biased to move from a first configuration to a second configuration having a different shape than the first configuration;
a proximal anchor attached to the proximal end of the shape-changing member and a distal anchor attached to the distal end of the shape-changing member, the proximal and distal anchors being expandable to engage an inner wall of a coronary sinus at a location adjacent the mitral valve annulus and at an opposed location on a posterior side of the inner wall of the coronary sinus; and
resorbable material engaging the shape-changing member to maintain the shape-changing member in the first configuration;
wherein the resorbable material has a design parameter to delay movement to the second configuration until expanded portions of the proximal and distal anchors have sufficiently grown into the coronary sinus to support the movement to the second configuration;
wherein, in the second configuration, the shape-changing member is configured to apply sufficient force to the coronary sinus to reshape the mitral valve annulus.
15. The medical device of claim 14 , wherein the distal anchor is collapsed in a first configuration that is suitable for delivery into the coronary sinus and is expanded in a second configuration that is suitable to engage the coronary sinus when deployed.
16. The medical device of claim 15 , wherein the distal anchor is a stent.
17. The medical device of claim 14 , wherein the shape-changing member is elongated in the first configuration and shortened in the second configuration.
18. The medical device of claim 14 , wherein the design parameter comprises a thickness of the resorbable material.