CN-114650782-B - Embolic device for occluding body cavities

Abstract

An embolic device for placement in a body lumen comprises an elongate member having a rectilinear configuration when at room temperature, the elongate member configured to form a first three-dimensional structure in response to body temperature, wherein the elongate member comprises a first section, a second section, and a third section, the second section being positioned between the first section and the third section, wherein the first section and the third section are configured to change their respective shapes in response to body temperature, and wherein the second section positioned between the first section and the third section has a shape independent of body temperature.

Inventors

• CHEN HANCUN

Assignees

• 史赛克公司
• 史赛克欧洲运营有限公司

Dates

Publication Date

20260505

Application Date

20201106

Priority Date

20191111

Claims (13)

1. 1. An embolic device for placement in a body lumen, the embolic device comprising: an elongate member having a rectilinear configuration when at room temperature, the elongate member being configured to form a three-dimensional structure in response to body temperature in a temperature range of 35 ℃ to 37.8 ℃ or 35 ℃ to 37.2 ℃, Wherein the elongate member comprises a first segment, a second segment and a third segment, the second segment being located between the first segment and the third segment, Wherein the first segment is martensitic when the first segment is at the room temperature and austenitic when the first segment is at the body temperature, Wherein the second segment is martensitic when the second segment is at the room temperature and the second segment is also martensitic when the second segment is at the body temperature, and Wherein the third segment is martensitic when the third segment is at the room temperature and austenitic when the third segment is at the body temperature, Wherein the second segment is an irreversible martensitic segment and the first segment and the third segment are reversible martensitic segments, and wherein the irreversible martensitic segment is softer than the reversible martensitic segment.
2. 2. The embolic device of claim 1, wherein, in response to said body temperature, said first segment is configured to form a first portion of a loop and said third segment is configured to form a second portion of said loop.
3. 3. The embolic device of claim 1, wherein, in response to said body temperature, said first segment is configured to form a first loop and said third segment is configured to form a second loop.
4. 4. An embolic device according to claim 1, Wherein the first segment has a first length, the second segment has a second length, and the third segment has a third length, and Wherein the second length of the second segment is shorter than the first length of the first segment and is also shorter than the third length of the third segment.
5. 5. The embolic device of claim 4, wherein said second length of said second segment between said first segment and said third segment is less than 50% of said first length of said first segment, and also less than 50% of said third length of said third segment.
6. 6. The embolic device of any of claims 1-5, Wherein the elongate member has a distal end and a proximal end opposite the distal end, Wherein the embolic device further comprises a fourth segment comprising the proximal end, and Wherein the fourth segment is martensitic when at the room temperature and the fourth segment is also martensitic when at the body temperature.
7. 7. The embolic device of any of claims 1-6, wherein said three-dimensional structure comprises a plurality of rings, and wherein said first, second, and third segments comprise respective portions of a single ring of said plurality of rings.
8. 8. An embolic device according to claim 7, Wherein the elongate member further comprises a fourth segment, a fifth segment and a sixth segment, the fourth segment, the fifth segment and the sixth segment comprising respective portions of another one of the plurality of rings, Wherein the fifth segment is located between the fourth segment and the sixth segment, Wherein the fourth segment and the sixth segment are martensitic when the fourth segment and the sixth segment are at the room temperature and austenitic when the fourth segment and the sixth segment are at the body temperature, an Wherein the fifth segment is martensitic when the fifth segment is at the room temperature and the fifth segment is also martensitic when the fifth segment is at the body temperature.
9. 9. The embolic device of claim 1, wherein said elongate member further comprises a fourth segment, a fifth segment, and a sixth segment, Wherein the fifth segment is located between the fourth segment and the sixth segment, Wherein the fourth segment and the sixth segment are configured to change respective shapes of the fourth segment and the sixth segment in response to the body temperature, and Wherein the fifth segment between the fourth segment and the sixth segment has a shape independent of the body temperature.
10. 10. The embolic device of claim 1, wherein said first and third segments are configured to change respective shapes of said first and third segments in response to said body temperature, and Wherein the second segment between the first segment and the third segment has a shape independent of the body temperature.
11. 11. The embolic device of claim 1, wherein said second segment is located between two rings.
12. 12. The embolic device of claim 1, wherein said second segment is located at an inflection point between two rings.
13. 13. The embolic device of claim 1, wherein said elongated member is a braided structure, and wherein a braiding angle along a length of said elongated member is variable.

Description

Embolic device for occluding body cavities FIELD The field of the present disclosure relates to medical devices and methods for occluding a body lumen, and more particularly, to medical devices and methods for occluding an aneurysm. Background An aneurysm is a type of vasodilation that can lead to rupture, clotting or dissection, thus constituting a health risk. Rupture of an aneurysm in the brain may cause stroke, and rupture of an aneurysm in the abdomen may cause shock. Cerebral aneurysms are commonly found in patients due to seizures or bleeding and can lead to higher morbidity or mortality. Various materials and devices have been used to treat aneurysms, including platinum and stainless steel microcoils, polyvinyl alcohol sponges (Ivalone), and other mechanical devices. For example, vascular occlusion devices are surgical instruments or implants that are typically placed through a catheter within the vascular system of a human body to block the flow of blood through a blood vessel that forms part of the vascular system by the formation of an embolic, or to form such an embolic within an aneurysm stemming from the blood vessel. Sometimes, when the vaso-occlusive device is carried within a catheter, the vaso-occlusive device elastically flexes to conform to the contours of the catheter. This elastic bending of the vaso-occlusive device creates various pressure points on the inner surface of the catheter, which may be undesirable because it makes advancement of the vaso-occlusive device relative to the catheter more difficult. In some instances, it may be desirable to apply an increased axial force in order to push the vaso-occlusive device distally. Such increased axial forces may sometimes cause premature buckling of the vaso-occlusive device within the catheter. Furthermore, the vaso-occlusive device may take on some three-dimensional shape after it is deployed outside the catheter. If the deployed vaso-occlusive device is too stiff, it may not conform to the shape of the body lumen that the vaso-occlusive device is intended to occlude. On the other hand, if the deployed vaso-occlusive device is too flexible, the vaso-occlusive device may not retain its shape and may inadvertently bend into an undesired shape, thereby rendering it unable to occlude the body lumen. SUMMARY An embolic device (empolic device) for placement in a body lumen includes an elongate member having a linear configuration when at room temperature, the elongate member configured to form a first three-dimensional structure in response to body temperature, wherein the elongate member includes a first segment, a second segment, and a third segment, the second segment being positioned between the first segment and the third segment, wherein the first segment and the third segment are configured to change their respective shapes in response to body temperature, and wherein the second segment positioned between the first segment and the third segment has a shape independent of body temperature. Optionally, in response to body temperature, the first segment is configured to form a first portion of the loop and the third segment is configured to form a second portion of the loop. Optionally, in response to body temperature, the first segment is configured to form a first loop and the third segment is configured to form a second loop. Optionally, the first segment has a first length, the second segment has a second length, and the third segment has a third length, and wherein the second length of the second segment is shorter than the first length of the first segment and is also shorter than the third length of the third segment. Optionally, the second length of the second segment between the first segment and the third segment is less than 50% of the first length of the first segment and also less than 50% of the third length of the third segment. Optionally, the elongate member has a distal end and a proximal end opposite the distal end, and wherein the embolic device further comprises a fourth segment comprising the proximal end, and wherein the fourth segment is martensitic when the fourth segment is at room temperature and also martensitic when the fourth segment is at body temperature. Optionally, the first segment is martensitic when the first segment is at room temperature and the first segment is austenitic when the first segment is at body temperature. Optionally, the second segment is martensitic when the second segment is at room temperature and the second segment is martensitic when the second segment is at body temperature. Optionally, the three-dimensional structure comprises a plurality of rings, and wherein the first segment, and the third segment comprise respective portions of one of the rings. Optionally, the elongate member further comprises a fourth segment, a fifth segment and a sixth segment, the fourth segment, the fifth segment and the sixth segment comprising respective portions of another one of the loops, wherei