Removeable embolus blood clot filter and filter delivery unit

• US 8,133,251 B2
• Filed: 06/10/2005
• Issued: 03/13/2012
• Est. Priority Date: 09/25/1998
• Status: Expired due to Term

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Ravenscroft, Adrian C., Kleshinski, Stephen J.
• Primary Examiner(s): Bui, Vy Q
• Application Number:
  US11/150,661
• Publication Number:
  US 20050234503A1
• Time in Patent Office: 2,468 Days
• Field of Search: 606191-200, 623/1.11, 604 94- 96, 604/164
• US Class Current: 606/200
• CPC Class Codes: A61F 2/0103 With centering means
• CPC Class Codes: A61F 2/0105 Open ended, i.e. legs gathered only at one side
• CPC Class Codes: A61F 2/011 Instruments for their placement or removal
• CPC Class Codes: A61F 2002/016 made from wire-like elements
• CPC Class Codes: A61F 2220/0008 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2230/008 paraboloidal

Abstract

A blood clot filter which is collapsible toward a central longitudinal axis into a collapsed configuration for insertion into a blood vessel and which is radially expandable outwardly from the longitudinal axis to an expanded configuration for contact with the inner wall of the blood vessel at two longitudinal spaced locations. A first plurality of spaced, elongate arms, in the expanded configuration of the filter, curve outwardly away from the longitudinal axis toward the leading end of the filter to form a first filter basket and to center a hub at the trailing end of the filter within the vessel. A second plurality of spaced elongate legs angle outwardly away from the longitudinal axis toward the leading edge of the filter in the expanded configuration thereof to form a second filter basket opening toward the leading end. The ends of these legs include hooks to bend and straighten in response to withdrawal force.

Claims

1. A method of recovering a blood filter implanted in a blood vessel, the blood filter having a plurality of legs that extend from a hub and radially spaced about a longitudinal axis, each of the legs having a hook coupled to a wall of the blood vessel, the hook having a curved profile, the method comprising:

deforming the hook of each of the legs from the curved profile towards a generally straight profile by applying a force greater than 70 grams to each leg in a direction along the longitudinal axis towards the hub to separate the hook of the blood filter from the wall of the blood vessel, the hook having an elasticity greater than an elasticity of its corresponding leg; and

forcing the plurality of legs to move towards the longitudinal axis.

2. The method of claim 1, wherein the applying comprises applying a force greater than 420 grams to the hub to separate the hooks of the blood filter from the wall of the blood vessel of about 28 millimeters.

3. The method of claim 2, wherein the deforming comprises bending each of the hooks toward a generally straight configuration to release a tip of the hook from the blood vessel wall.