Filamentary devices for treatment of vascular defects
Devices and methods for treatment of a patient's vasculature are described. The devices include implants made of woven braided mesh having a variable mesh density, i.e., the average size of pores in one region are a different than the average size of pores in another region. Additionally, there is a transition zone between the two regions. The implants have a low profile radially constrained state and an expanded state that is axially shortened. Methods of using the device to treat a cerebral aneurysm are also described. Methods of forming a tubular braid are also described. Methods of forming a tubular braid with variable braid densities are described. Methods of forming a tubular braid using a castellated mandrel are also described.
1. A device for treating a cerebral aneurysm, comprising:
an implant comprising a single layer of woven braided mesh, the implant having a proximal end with a hub, a distal end, and a longitudinal axis extending from the proximal end to the distal end, and a length;
the implant having a distal region having a plurality of pores having an average diameter, a proximal region having a plurality of pores having an average diameter, and a transition region that lies substantially perpendicular to the longitudinal axis of the implant and extends between the distal and proximal regions and has a length;
the implant having an expanded globular configuration when deployed, the expanded implant having a region of maximum diameter that extends from a proximal portion of the distal region through the transition region and to a distal portion of the proximal region,
wherein the average diameter of the plurality of pores in the distal region is greater than the average diameter of the plurality of pores in the proximal region, and wherein the length of the transition region is about 0.5% to about 20% of the length of the implant.
2. The device of claim 1 , wherein the average diameter of the plurality of pores in the distal region is greater than 250 μm.
3. The device of claim 1 , wherein the average diameter of the plurality of pores in the distal region is greater than 400 μm.
4. The device of claim 1 , wherein the average diameter of the plurality of pores in the distal region is between about 250 μm to about 500 μm or between about 300 μm to about 600 μm.
5. The device of claim 1 , wherein the average diameter of the plurality of pores in the proximal region is 200 μm or less.
6. The device of claim 1 , wherein the average diameter of the plurality of pores in the proximal region is between about 50 μm to about 200 μm.
7. The device of claim 1 , wherein the average diameter of the plurality of pores in the proximal region is between about 100 μm to about 200 μm.
8. The device of claim 1 , wherein the length of the transition region is about 1% to about 15% of the length of the implant.
9. The device of claim 1 , wherein the length of the transition region is about 1% to about 10% of the length of the implant.
10. The device of claim 1 , wherein the length of the transition region is about 3% to about 8% of the length of the implant.
11. A method for treating a cerebral aneurysm, comprising the steps of:
providing an implant comprising a single layer of woven braided mesh, the implant having a proximal end with a hub, a distal end, and a longitudinal axis extending from the proximal end to the distal end, and a length,
wherein the implant has a distal region having a plurality of pore having an average diameter, a proximal region having a plurality of pore having an average diameter, and a transition region that lies substantially perpendicular to the longitudinal axis of the implant and extends between the distal and proximal regions and has a length;
wherein the implant has an expanded globular configuration when deployed, the expanded implant having a region of maximum diameter that extends from a proximal portion of the distal region through the transition region and to a distal portion of the proximal region,
wherein the average diameter of the plurality of pores in the distal region is greater than the average diameter of the plurality of pores in the proximal region, and wherein the length of the transition zone may be about 0.5% to about 20% of the length of the implant;
advancing the implant in the low profile radially constrained state within a microcatheter to a region of interest within a cerebral artery;
deploying the implant within the cerebral aneurysm, wherein the distal and proximal permeable shells expand to their expanded shapes; and
withdrawing the microcatheter from the region of interest after deploying the implant.
12. The method of claim 11 , wherein the average diameter of the plurality of pores in the distal region is greater than 250 μm.
13. The method of claim 11 , wherein the average diameter of the plurality of pores in the distal region is greater than 400 μm.
14. The method of claim 11 , wherein the average diameter of the plurality of pores in the distal region is between about 250 μm to about 500 μm or between about 300 μm to about 600 μm.
15. The method of claim 11 , wherein the average diameter of the plurality of pores in the proximal region is 200 μm or less.
16. The method of claim 11 , wherein the average diameter of the plurality of pores in the proximal region is between about 50 μm to about 200 μm.
17. The method of claim 11 , wherein the average diameter of the plurality of pores in the proximal region is between about 100 μm to about 200 μm.
18. The method of claim 11 , wherein the length of the transition region is about 1% to about 15% of the length of the implant.
19. The method of claim 11 , wherein the length of the transition region is about 1% to about 10% of the length of the implant.
20. The method of claim 11 , wherein the length of the transition region is about 3% to about 8% of the length of the implant.