Method and device for filtering body fluid

Abstract

Medical devices for filtering fluids flowing through a lumen and a method of forming medical devices. The devices can be used in vascular channels, urinary tracts, biliary ducts and the like, and filter emboli and other debris generated at a treatment site.

Description

[0001] This application is a continuation of U.S. application Ser. No. 10 / 051,492, filed Jan. 18, 2002, which is a continuation of U.S. application Ser. No. 08 / 748,066, filed Nov. 12, 1996, now U.S. Pat. No. 6,605,102, issued Aug. 12, 2003, which is a continuation of U.S. application Ser. No. 08 / 272,425, filed Jul. 8, 1994, now abandoned.FIELD OF THE INVENTION [0002] The present invention generally relates to intravascular devices for treating certain medical conditions and, more particularly, provides a method of forming intravascular devices and certain novel intravascular occlusion devices. The devices made in accordance with the invention are particularly well suited for delivery through a catheter or the like to a remote location in a patient's vascular system or in analogous vessels within a patient's body. BACKGROUND OF THE INVENTION [0003] A wide variety of intravascular devices are used in various medical procedures. Certain intravascular devices, such as catheters and guid...

AI Technical Summary

Benefits of technology

[0012] The present invention provides a method for forming intravascular devices from a resilient metal fabric and medical devices which can be formed in accordance with this method. In the method of the invention, a metal fabric formed of a plurality of resilient strands is provided, with the wires being formed of a resilient material which can be heat treated to substantially set a desired shape. This fabric is then deformed to generally conform to a molding surface of a molding element and the fabric is heat treated in contact with the surface of the molding element at an elevated temperature. The time and temperature of the heat treatment is selected to substantially set the fabric in its deformed state. After the heat treatment, the fabric is removed from contact with the molding element and will substantially retain its shape in the deformed state. The fabric so treated defines an expanded state of a medical device which can be deployed through a catheter into a channel in a patient's body.

Problems solved by technology

In part due to the inability to precisely position the embolization agents, this procedure is often limited in its utility.

Such balloon embolizations are also prone to certain safety problems, though.

However, such filters generally have not proven to be exceptionally effective in actual use.

Such filters tend to be cumbersome to use and accurate deployment is problematic because if they are not properly seated in the vessel they can drift to a more distal site where they are likely to do more harm than good.

In addition, these filters are generally capable of only trapping relatively large thrombi and are not effective means for removing smaller embolic particles from the blood stream.

The problems with temporary filters, which are intended to be used only during a particular procedure then retracted with the thrombi trapped therein, are more pronounced.

Even if the trap does effectively capture the dislodged material, it has proven to be relatively difficult or complex to retract the trap back into the catheter through which it was delivered without simply dumping the trapped thrombi back into the blood stream, defeating the purpose of the temporary filter device.

Even if some of those devices have proven effective, they tend to be rather expensive and time-consuming to manufacture.

Not only does this take significant skilled manpower, and hence increase the costs of such devices, the fact that each item must be made by hand tends to make quality control more difficult.

This same difficulty and expense of manufacturing is not limited to such filters, but is experienced in many other intravascular devices as well.

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