BRAIDED VASCULAR DEVICES HAVING NO END CLAMPS
In some embodiments, a medical device may include one or more of the following features: (a) a metal fabric formed of braided metal strands, (b) the medical device having a collapsed configuration for delivery through a channel in a patient's body and having a generally dumbbell-shaped expanded configuration with two expanded diameter portions separated by a reduced diameter portion formed between opposed ends of the device and unsecured metal strand ends at the opposed ends, and (d) a thrombogenic agent located on the metal fabric.
1 . A collapsible medical device, comprising:
at least one layer of a plurality of metal strands woven into a tubular braided metal fabric having a proximal end, a distal end, and a segment there between;
the tubular woven metal fabric having an expanded preset configuration shaped for treatment of an opening in a body organ; and
the expanded preset configuration being deformable to a lesser cross-sectional dimension for delivery through a channel in a patient's body, the woven metal fabric having a memory property whereby the medical device returns to the expanded preset configuration when delivered into the patient's body, said proximal and distal ends being free of clamps and having at least a portion of the segment larger in diameter than the free wire ends in the expanded preset configuration.
2 . The collapsible medical device of claim 1 , wherein the medical device is an occluder.
3 . The collapsible medical device of claim 1 , wherein the medical device is a shunt.
4 . The collapsible medical device of claim 1 , wherein the medical device is a flow restrictor.
5 . The collapsible medical device of claim 1 , further comprising an occluding fiber retained within an expandable hollow central portion formed by said tubular woven fabric.
6 . The collapsible medical device of claim 1 , wherein the metal fabric is manufactured from an alloy selected from the group consisting of stainless steel, nickel-titanium, and cobalt-chromium-nickel.
7 . The collapsible medical device of claim 1 , wherein the device comprising the expanded preset configuration is the shape of a disc.
8 . A medical device comprising:
a metal fabric formed of braided metal strands;
the medical device having a collapsed configuration for delivery through a channel in a patient's body and having a generally dumbbell-shaped expanded configuration with two expanded diameter portions separated by a reduced diameter portion formed between opposed ends of the device and unsecured metal strand ends at the opposed ends.
9 . The medical device of claim 8 , wherein the medical device can be any one of an occluder, shunt, or flow restrictor.
10 . The medical device of claim 8 , wherein the metal strand ends are unsecured from metal clamps.
11 . The medical device of claim 8 , wherein the metal strand ends do not unravel.
12 . The medical device of claim 8 , wherein the medical device is delivered to a treatment site in a patient without physical connection to a delivery device.
13 . The medical device of claim 8 , wherein the unsecured metal strand ends do not extend outside of the expanded diameter portions.
14 . The medical device of claim 8 , further comprising a thrombogenic agent located on the metal fabric.
15 . A method of forming a medical device, the method comprising the steps of: providing a metal fabric formed of a plurality of braided strands, the strands being formed of a metal which can be heat treated to substantially set a desired shape;
deforming the metal fabric to generally conform to a wall surface of a moulding element;
heat treating the metal fabric in contact with the surface of the moulding element at an elevated temperature, the temperature and the duration of the heat treatment being sufficient to substantially set the shape of the fabric in its deformed state;
removing the metal fabric from contact with the moulding element; and
cutting the fabric adjacent the device side of the clamps after heat treatment.
16 . The method of claim 15 , further comprising the step of clamping the opposite ends of the strands before deforming the metal fabric.
17 . The method of claim 15 , further comprising the step of cutting an appropriately sized piece of the metal fabric.
18 . The method of claim 17 , further comprising the step of forming a long tubular braid from the metal fabric.
19 . The method of claim 15 , wherein the metal of which the strands are formed is a shape memory alloy, stainless steel, or elgiloy, the temperature and the duration of the heat treatment being selected to substantially set the strands in a deformed state.
20 . A method for delivering a self-expanding medical device to a selected site in a vascular system comprising the steps of:
(a) selecting the combination of: (i) a delivery device inner catheter having a lumen extending from a proximal end to a distal end, the delivery device having an outer diameter adapted to slidingly fit within the lumen of a delivery catheter, (ii) an elongate, flexible member coaxially insertable through the lumen of the delivery device catheter, said elongate flexible member having a plunger member affixed thereto sized to at least partially fit within the lumen of the delivery device catheter when a proximally directed tension force is applied to the elongate flexible member with respect to the delivery device catheter, (iii) a braided tubular device having at least a portion of a segment larger in diameter than free wire ends in the expanded preset configuration with the free ends of individual strands comprising the device captured between the plunger member and the delivery device catheter;
(b) feeding the delivery device catheter with the braided tubular device attached through a lumen of the delivery catheter and out thereof; and
(c) moving the elongate flexible member relative to the tubular delivery device catheter to release the tubular device from the tubular delivery device catheter.
21 . The method of claim 20 , further comprising the step of releasing a plunger spring located in the plunger member to capture the free ends between the plunger member and the inner delivery device catheter.
22 . The method of claim 20 , further comprising the step of inserting the delivery catheter within a patient's vasculature.
23 . The method of claim 20 , further comprising the step of repositioning the braided tubular device if it is not positioned properly upon release from the tubular delivery device catheter.
24 . The method of claim 20 , further comprising removing the delivery device form the patient's vasculature.
25 . The method of claim 20 , further comprising removing the delivery catheter from the patient's vasculature.