METHOD FOR MAKING BRAIDED MEDICAL DEVICES
A method for making a braided medical device may involve positioning an insert inside a braided material, processing the braided material to form the braided medical device, dissolving and/or crushing the insert into multiple pieces, and removing the multiple pieces from the braided medical device. In some embodiments, the insert is made of gypsum. A braided medical device for occluding a defect in a heart may include a right disc for residing in a right side of the heart, a left disc having a partially circular shape for residing in a left side of the heart, and a waist extending between the right disc and the left disc and having a smaller diameter than that of either the right disc or the left disc.
1 . A method for making a braided medical device, the method comprising:
positioning a frangible insert inside a braided structure;
processing the braided structure to form the braided medical device; and
removing the frangible insert from the braided medical device.
2 . The method of claim 1 , wherein the frangible insert comprises gypsum.
3 . The method of claim 1 , further comprising attaching a radiopaque marker band to the braided structure at at least one end of the braided medical device.
4 . The method of claim 3 , wherein attaching the radiopaque marker band comprises one or more of crimping, swaging, and welding.
5 . The method of claim 1 , wherein the frangible insert is configured to constrain and define an inner shape of the braided structure during processing.
6 . The method of claim 1 , wherein processing the braided structure comprises:
loading the braided structure into a forming mold;
heating the forming mold to a temperature high enough to affect a phase transformation in a material of the braided structure and calcination of the frangible insert; and
quenching the forming mold.
7 . The method of claim 1 , wherein removing the frangible insert comprises crushing the frangible insert into multiple pieces and washing the multiple pieces out of the braided medical device with water.
8 . The method of claim 1 , wherein removing the frangible insert comprises dissolving the frangible insert with water.
9 . The method of claim 1 , further comprising sewing a fabric onto the braided medical device.
10 . The method of claim 1 , wherein the braided medical device comprises a closure device for a heart defect.
11 . A braided medical device for occluding a defect in a heart, the device comprising:
a right disc for residing in a right side of the heart;
a left disc for residing in a left side of the heart, wherein a portion of the left disc is non-circular; and
a waist extending between the right disc and the left disc and having a diameter smaller than a diameter of the right disc and a diameter of the left disc.
12 . The device of claim 11 , wherein at least the right disc and the left disc comprise a shape memory material.
13 . The device of claim 11 , wherein the right disc, the left disc, and the waist comprise:
an inner layer of braided wires having a first stiffness; and
an outer layer of braided wires having a second stiffness that is less than the first stiffness.
14 . The device of claim 13 , wherein the waist comprises a space between the inner layer and the outer layer.
15 . The device of claim 11 , wherein the right disc is circular.
16 . The device of claim 11 , wherein the left disc comprises:
a top portion that is non-circular; and
a bottom portion that is circular.
17 . The device of claim 16 , wherein a top edge of the top portion extends from one millimeter to four millimeters above a top edge of the waist.
18 . The device of claim 17 , wherein each of a right top corner and a left top corner of the top portion extends radially farther beyond an outer edge of the right disc than the top edge of the top portion extends radially beyond a top edge of the right disc.
19 . The device of claim 11 , further comprising a fabric attached to one or more of the right disc, the left disc, and the waist.
20 . The device of claim 11 , further comprising radiopaque markers coupled to each end of the braided medical device.