Occluder medical device

1 . A medical device for treating a target site, the medical device comprising:

a body extending from a proximal end to a distal end along a central longitudinal axis, the body comprising a proximal disc adjacent the proximal end, a distal disc adjacent the distal end, and a waist extending between and connecting the proximal disc and the distal disc, the body further comprising:

an inner layer formed from a first braided self-expanding material; and

an outer layer formed from a second braided self-expanding material, wherein the outer layer surrounds the inner layer and is independent from the inner layer,

wherein each of the proximal disc, the distal disc, and the waist are defined in part by each of the inner layer and the outer layer,

wherein the distal disc includes an outer distal disc formed by the outer layer and an inner distal disc formed by the inner layer, and the waist includes an outer waist formed by the outer layer and an inner waist formed by the inner layer, the outer distal disc having an outer proximal surface, an outer distal surface, and an outer peripheral surface extending between the outer proximal surface and the outer distal surface, and the inner distal disc having an inner proximal surface, an inner distal surface and an inner peripheral surface extending between the inner proximal surface and the inner distal surface, in an expanded configuration of the medical device, the inner peripheral surface of the inner distal disc is positioned between the outer proximal surface and the outer distal surface of the outer distal disc and the inner waist contacts the outer waist,

wherein, in the expanded configuration of the medical device, the outer proximal surface extends proximally and is tapered towards the outer waist such that a diameter of the outer proximal surface decreases gradually between an interface with the outer peripheral surface and an interface with the outer waist,

wherein the outer layer comprises a pic transition at or near the interface between the outer proximal surface and the outer waist, such that (i) the pic transition in combination with the tapered outer proximal surface facilitates seating of the waist further into a defect at the target site before the outer peripheral surface contacts tissue at the defect and reduces the likelihood of prolapse of the distal disc during deployment, (ii) the pic transition improves the expansion of the distal disc during deployment of the medical device, and/or (iii) the pic transition facilitates increased elongation of the outer waist for improved deployability of the medical device and/or improved conformability of the outer layer to tissue at the target site, and

wherein the first braided self-expanding material forming the inner layer comprises a first number of wires and the second braided self-expanding material forming the outer layer comprises a second number of wires greater than the first number of wires.

2 . The medical device of claim 1 , wherein, in the expanded configuration of the medical device, a diameter of the inner distal disc extends halfway between a diameter of the outer waist and a diameter of the outer distal disc.

3 . The medical device of claim 1 , wherein the outer distal disc, the inner distal disc, the outer waist and the inner waist each has a diameter, in the expanded configuration of the medical device, a diameter of the outer distal disc extends radially about 6 mm to 8 mm beyond a diameter of the outer waist, and a diameter of the inner distal disc extends about 1 mm to 6 mm beyond a diameter of inner waist.

4 . The medical device of claim 1 , wherein the inner layer has a first softness, and the outer layer has a second softness greater than the first softness.

5 . The medical device of claim 4 , wherein the first braided self-expanding material comprises the first number of wires having a first wire diameter, and the second braided self-expanding material comprises the second number of wires having a second wire diameter less than the first wire diameter.

6 . The medical device of claim 5 , wherein the second wire diameter is selected to optimize the second softness of the outer layer, and wherein the first wire diameter is selected to optimize at least one of a radial strength and an axial strength of the inner layer.

7 . The medical device of claim 1 , wherein the inner waist has a first radial strength, and the outer waist has a second radial strength less than the first radial strength.

8 . The medical device of claim 1 , wherein the pic transition comprises an increasing braid density of the second braided self-expanding material along or adjacent to the interface between the outer proximal surface and the outer waist.

9 . The medical device of claim 1 , wherein the pic transition comprises a decreasing helix length of the second braided self-expanding material along or adjacent to the interface between the outer proximal surface and the outer waist.

10 . The medical device of claim 1 , wherein the proximal disc includes an outer proximal disc formed by the outer layer and an inner proximal disc formed by the inner layer, the outer proximal disc having an outer distal surface and an outer proximal surface, in the expanded configuration of the medical device, the outer distal surface of the outer proximal disc being tapered toward the outer waist, such that a diameter of the outer distal surface of the outer proximal disc gradually decreases toward the outer waist.

11 . The medical device of claim 1 , wherein the pic transition results in an increased braid density of the outer layer at or near the outer waist.

12 . The medical device of claim 1 , wherein, in the expanded configuration of the medical device, a diameter of the inner waist is the same as a diameter of the outer waist.

13 . The medical device of claim 1 , further comprising an occlusive patch material positioned between the outer layer and the inner layer.

14 . The medical device of claim 13 , wherein the occlusive patch material is positioned within at least one of the distal disc and the proximal disc between the outer layer and the inner layer.

15 . The medical device of claim 13 , wherein the occlusive patch material is positioned within each of the distal disc, the proximal disc, and the waist between the outer layer and the inner layer.

16 . The medical device of claim 1 , wherein the proximal disc includes an outer proximal disc formed by the outer layer and an inner proximal disc formed by the inner layer, the outer proximal disc having an outer distal surface, an outer proximal surface, and an outer peripheral surface extending between the outer distal surface and the outer proximal surface, the outer peripheral surface of the outer proximal disc having a rounded profile.

17 . A method of forming the medical device of claim 1 , the method comprising:

selecting the first braided self-expanding material for forming the inner layer of the medical device, said selecting comprising selecting at least one of a wire count, a wire diameter, and a braid pattern of the first braided self-expanding material to optimize a radial strength of the inner layer formed using the first braided self-expanding material;

selecting the second braided self-expanding material for forming the outer layer of the medical device, said selecting comprising selecting at least one of a wire count, a wire diameter, and a braid pattern of the second braided self-expanding material to optimize a softness of the outer layer formed using the second braided self-expanding material;

enclosing the first braided self-expanding material within the second braided self-expanding material; and

forming the inner layer and the outer layer of the medical device by molding the first and second braided self-expanding materials, the inner layer comprising the inner distal disc, the inner waist, and an inner proximal disc, and the outer layer comprising the outer distal disc, the outer waist, and an outer proximal disc.

18 . The method of claim 17 , wherein said forming the inner layer and the outer layer of the medical device comprises forming the inner distal disc to be significantly smaller than the outer distal disc.

19 . The method of claim 17 , further comprising:

positioning an occlusive patch material between the inner layer and the outer layer; and

coupling the occlusive patch material to at least one of the inner layer and the outer layer.

20 . The method of claim 17 , wherein said selecting the second braided self-expanding material comprises selecting a pic transition at a location along or adjacent to the outer waist when the outer layer is formed using the second braided self-expanding material.