BLOOD FLOW DISRUPTION DEVICES AND METHODS FOR THE TREATMENT OF VASCULAR DEFECTS

1 . A blood flow disruption device for embolizing blood flowing into a vascular defect located between a proximal vascular segment and a distal vascular segment, the device comprising:

a porous inner flow disruption element configured to extend through the defect between the proximal vascular segment and the distal vascular segment, whereby a first portion of the blood flowing into the inner flow disruption element from the proximal vascular segment is directed to flow into the defect and a second portion of the blood flowing into the inner flow disruption element is directed to flow into the distal vascular segment; and

a porous outer flow disruption element coaxially surrounding the inner flow disruption element and radially expansible from a collapsed state to an expanded state;

wherein the outer flow disruption element, in its expanded state, promotes sufficient hemostasis of the first portion of the blood within the defect to embolize the defect.

2 . The device of claim 1 , wherein the inner flow disruption element has a proximal fixation zone configured to be seated in the proximal vascular segment and a distal fixation zone configured to be seated in the distal vascular segment.

3 . The device of claim 1 , wherein the outer flow disruption element, in its expanded state, is configured as an undulated flow baffle.

4 . The device of claim 1 , wherein the inner flow disruption element includes a filamentous mesh formed into a tubular configuration.

5 . The device of claim 4 , wherein the inner flow disruption element is formed from a mesh of filaments selected from the group consisting of at least one of metallic filaments and polymeric filaments.

6 . The device of claim 5 , wherein the mesh of filaments comprises a first plurality of pore-defining filaments having a first diameter, and a second plurality of reinforcing filaments having a second diameter greater than the first diameter.

7 . The device of claim 6 , wherein the pore-defining filaments form a porous wall for the inner disruption element, the porous wall defining pores having a predefined pore size.

8 . The device of claim 1 , wherein the outer flow disruption element is formed from a mesh of filaments selected from the group consisting of at least one of metallic filaments and polymeric filaments.

9 . The device of claim 1 , wherein the outer flow disruption element is a first outer flow disruption element, the device further comprising a second outer flow disruption element coaxially surrounding the first outer flow disruption element and radially expansible from a collapsed state to an expanded state.

10 . A blood flow disruption device for embolizing blood flowing into a vascular defect located between a proximal vascular segment and a distal vascular segment in a parent artery, the device comprising:

a porous inner flow disruption element configured to extend through the defect between the proximal vascular segment and the distal vascular segment so as to provide a lumen within the vascular defect from the proximal vascular segment to the distal vascular segment; and

an outer flow disruption element coaxially surrounding at least a portion of the inner flow disruption element and radially expansible from a collapsed state to an expanded state;

wherein the inner flow disruption element and the outer flow disruption element define a plurality of substantially closed sub-volumes within the vascular defect.

11 . The device of claim 10 , wherein at least one of the substantially closed sub-volumes has a generally toroidal shape.

12 . The device of claim 10 , wherein the inner element has a first diameter and the outer element has a second diameter that is about 225% to about 700% the first diameter.

13 . The device of claim 10 , wherein the vascular defect has a total defect volume, and wherein at least one of the substantially closed sub-volumes is between about 10% and 80% of the total defect volume.

14 . The device of claim 13 , wherein all of the substantially closed sub-volumes comprise between about 40% and 100% of the total defect volume.

15 . The device of claim 10 , wherein the outer flow disruption element, in its expanded state, promotes sufficient hemostasis of blood within the defect to embolize the defect.

16 . The device of claim 15 , wherein the hemostasis promoted within the vascular defect is such that substantially no contrast agent can be seen during an angiogram in the defect when the defect is embolized.

17 . A method of treating a vascular defect located between a proximal vascular segment and a distal vascular segment, the method comprising:

providing a blood flow disruption device comprising a porous inner flow disruption element having a proximal fixation zone and a distal fixation zone and configured to extend through the defect between the inflow end and the outflow end, and a porous outer flow disruption element coaxially surrounding the inner flow disruption element and radially expansible from a collapsed state to an expanded state;

delivering the blood flow disruption device intravascularly to the vascular defect with the outer flow disruption element in its collapsed state;

installing the device in the vascular defect so that the device bridges the defect, with the proximal fixation zone of the inner flow disruption element seated in the proximal vascular segment and the distal fixation zone of the inner flow disruption element seated in the distal vascular segment, and with the outer flow disruption element in its expanded state;

directing a flow of blood into the defect from the proximal vascular segment through the inner flow disruption element; and

using the outer flow disruption element to disrupt the flow of blood entering the defect so as to promote sufficient hemostasis to form an embolism in the defect external to the inner flow disruption element.

18 . The method of claim 17 , wherein the outer flow disruption element in the provided device coaxially has an inflow end attached to the proximal fixation zone of the inner flow disruption element and an outflow end attached to the distal fixation zone of the inner flow disruption element.

19 . The method of claim 17 , wherein the delivering is performed by:

(a) delivering the outer flow disruption element intravascularly to the vascular defect while the outer flow disruption element is in its collapsed state;

(b) radially expanding the outer flow disruption element within the defect; and

(c) delivering the inner flow disruption element intravascularly to the defect so as to be coaxially surrounded by the outer flow disruption element.

20 . The method of claim 19 , wherein the installing is performed by:

(a) seating the outflow end of the outer flow disruption device in the distal vascular segment;

(b) seating the inflow end of the outer flow disruption device in the proximal vascular segment;

(c) seating the distal fixation zone of the inner flow disruption element in the distal vascular segment so as to capture the outflow end of outer flow disruption element between the distal fixation zone of the inner flow disruption device and the distal vascular segment; and

(d) seating the proximal fixation zone of the inner flow disruption element in the proximal vascular segment so as to capture the inflow end of the outer flow disruption element between the proximal fixation zone of the inner flow disruption element and the proximal vascular segment.

21 . The method of claim 17 , wherein, after the embolism is formed, the inner flow disruption element forms a stent through the embolism through which blood flows from the proximal vascular segment to the distal vascular segment.

22 . The method of claim 17 , wherein the outer flow disruption element, in its expanded state, is configured as an undulated flow baffle.

23 . The method of claim 17 , wherein the inner flow disruption element includes a filamentous mesh formed into a tubular configuration.

24 . The method of claim 23 , wherein the inner flow disruption element is formed from a mesh of filaments selected from the group consisting of at least one of metallic filaments and polymeric filaments.

25 . The method of claim 24 , wherein the mesh of filaments comprises a first plurality of pore-defining filaments having a first diameter, and a second plurality of reinforcing filaments having a second diameter greater than the first diameter.

26 . The method of claim 25 , wherein the pore-defining filaments form a porous wall for the inner flow disruption element, the porous wall defining pores having a predefined pore size.

27 . The method of claim 17 , wherein the outer flow disruption element is formed from a mesh of filaments selected from the group consisting of at least one of metallic filaments and polymeric filaments.

28 . A method of treatment of a vascular defect between an upstream vascular segment and a downstream vascular segment of an artery, the method comprising;

(a) providing a first radially expansible porous mesh element having a distal end and a proximal end and at least one radial undulation between its distal and proximal ends;

(b) deploying the first porous mesh element in the artery such that the proximal end of the first mesh element extends into the upstream vascular segment;

(c) providing a second radially expansible porous mesh element having a distal end a proximal end; and

(d) deploying the second radially expansible porous mesh element coaxially within the first mesh element, such that the distal end of the second mesh element extends into the downstream vascular segment and the proximal end of the second mesh element extends into the upstream vascular segment, so that at least one substantially closed space is created within the defect by the first and second mesh elements.

29 . The method of claim 28 , wherein the at least one substantially closed space is generally toroidal.

30 . The method of claim 28 , wherein at least one additional radially expansible porous mesh element is deployed in an over-lapping manner with at least one of the first and second mesh elements, the at least one additional mesh element and extending into the downstream vascular segment.

31 . The method of claim 28 , further comprising:

(e) using the first and second elements to promote sufficient hemostasis within the vascular defect such that when contrast agent is injected in a follow-up angiogram, no significant contrast can be seen outside the second mesh element within about 24 hours after deployment of the second mesh element.

32 . The method of claim 28 , wherein the deploying of the first porous mesh element is performed such that the distal end of the first mesh element extends into the downstream vascular segment, and the proximal end of the first mesh element extends into the upstream vascular segment.