|Publication number||US20070032816 A1|
|Application number||US 11/278,601|
|Publication date||Feb 8, 2007|
|Filing date||Apr 4, 2006|
|Priority date||Apr 4, 2005|
|Also published as||CA2603760A1, EP1868526A1, US8734481, US20110106133, WO2006107939A1|
|Publication number||11278601, 278601, US 2007/0032816 A1, US 2007/032816 A1, US 20070032816 A1, US 20070032816A1, US 2007032816 A1, US 2007032816A1, US-A1-20070032816, US-A1-2007032816, US2007/0032816A1, US2007/032816A1, US20070032816 A1, US20070032816A1, US2007032816 A1, US2007032816A1|
|Inventors||Paul O'Connell, Guy Nadal|
|Original Assignee||B.Braun Medical|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (14), Classifications (8), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This patent claims benefit under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 60/668,036 filed Apr. 4, 2005, the disclosure of which is hereby expressly incorporated herein by reference.
This patent generally relates to filters for use in the treatment of vascular diseases, and more specifically to filters that include a removable filter head adapted to convert, in vivo, the filter from a filter configuration to an open, stent-like configuration.
Convertible filters for treating vascular disease are known from the present inventor's own U.S. Pat. Nos. 6,267,776 and 6,517,559, the disclosures of which are hereby expressly incorporated herein by reference. These patents disclose numerous embodiments of convertible filters and particularly convertible filters suitable for treatment of vascular disease such as atherosclerotic and embolismic disease.
Generally, convertible filters include a filter structure having a plurality of filter legs arranged to form a single or double cone filter basket within the vessel lumen to trap blood borne clots or plaque with the vessel. A release member releasable secures the legs or filtering elements of the filter structure such that the filter may have two distinct configurations: filter or open/stent-like. The conversion is affected by release of the release member from the filter legs allowing the spring action of the filter legs themselves or of an externally applied opening force, such the force of a spring coupled to the filter legs, to open the filter legs from the filter configuration to the stent-like configuration. The release member may be a biodegradable material that deteriorates over time to release the filter legs to move to the stent-like configuration.
In another convertible filter, the release member is a mechanical retainer that includes a hook or similar grasping structure to allow the release member to be physically separated from the filter structure. Removal of the release member involves engaging the grasping structure with a snare and forcing the separation of the release member from the filter structure. The filter structure, which is typically attached to the wall by endothelial tissue, resists the applied force. The release member needs to be releasable from the filter legs with a minimum of force so that the reaction force exerted by the filter legs on the vessel wall does cause detrimental damage to the integrity of the wall. A well-designed release member will facilitate release of the member from the filter legs without transferring significant forces through the filter structure into the vessel wall.
Upon separation of the release member from the filter legs, the filter structure opens to assume the stent-like configuration along the wall of the blood vessel.
For a more complete understanding of the invention, reference should be made to the following detailed description and accompanying drawings wherein:
The removable filter head including a release mechanism constructed in accordance with the teachings of the present invention provides a safe system for converting, in vivo, a convertible filter, such as a vena cava filter, from a closed, filter configuration to an open, stent-like configuration.
The removable filter head incorporates the release mechanism to releasably secure a plurality of interconnected intraluminal filter elements (filter elements) in a single or double cone filter structure or filter basket. The release mechanism includes a retainer adapted to receive the plurality of filter elements and a stopper movable, relative to the removable filter head and the retainer, between a secured position and an unsecured position. In operation, the filter elements are positioned within the retainer and held in position by, for example, the friction between the retainer, the filter elements and the stopper, when the stopper is in the secured position.
Movement of the stopper, relative to the removable filter head and the retainer, from the secured position adjacent to the retainer to the unsecured position, releases the filter elements while maintaining the position of the removable filter head relative to the filter elements and the wall of the blood vessel. Subsequently, the released filter elements can convert or expand from the filter configuration to the stent-like configuration when the removable filter head is physically separated from the filter elements.
The filter elements 14 in this exemplary embodiment are arranged in a single cone configuration and aligned within the blood vessel 12 in the direction of the blood flow indicated by the arrow A to trap matter carried within the blood flow, for example, dislodged blood clots or plaque. The filter elements 14 each include a filter leg 20 flexibly attached to an orientation member 22 at a flexure point 24. In operation, deployment of the convertible filter assembly 10 within the blood vessel 16 allows the orientation members 22 to engage the wall 18 of the blood vessel 12 and align the entire convertible filter assembly 10 with the blood flow. However, it is noted that the particular configuration of the convertible filter, single cone, dual cone, basket, stabilizing members or no stabilizing members, etc., is not critical, and the herein described removable filter head is adaptable to virtually any such structure.
The filter legs 20 include an inferior end 26 and a superior end 28 aligned along the wall 18 of the blood vessel 12 by the orientation member 22. In particular, the inferior end 26 is an unsecured portion of the filter leg 20 positioned upstream from the superior end 28. The superior end 28 is, in turn, bundled and secured together by the removable filter head 16 to form a filter basket generally indicated by the reference numeral 30. As used herein to assist the reader, the terms superior and inferior indicate the orientation of the convertible filter assembly 10 within the blood vessel 12 and relative to the direction of the blood flow (indicated by the arrow A). For example, the term inferior indicates a downstream position and the term superior indicates an upstream position relative to the direction of blood flow within the blood vessel 12.
The convertible filter assembly 10 including the removable filter head 16, the filter legs 20 and the orientation members 22 may be manufactured from a radiopaque and non-ferromagnetic metal that has been certified for use in medical devices by the International Standards Organization (ISO). The filter legs 20 and the orientation members 22 may be manufactured from metallic wires having, for example, a round, flat or any suitable cross-sectional shape. The convertible filter assembly 10 may be further drug-coated.
The wires may be a high cobalt, low ferrous alloy, such as the alloys sold under the registered trademark ELGILOY® which is also referred to as PHYNOX. The composition of these alloys may, by weight percent, be: cobalt 42%, chromium 21.5%, nickel 18%, iron 8.85%, molybdenum 7.5%, manganese 2% with the balance made up of carbon and beryllium having a maximum of 0.15% carbon and 0.001% beryllium. The wires may also be composed of 316L stainless steel or other alloys of nickel and titanium known to be shape-memory metals which are sold and manufactured under the registered trademark NITINOL® or an alloy of tantalum (Ta). Convertible filter assemblies 10 constructed from these metals will be non-thrombogenic and preferably withstand twelve million respiratory cycles without mechanical failure.
The removable filter head 16 is a roughly cylindrical body 44 that includes an open first end 46 and a second end 48 that includes a retainer 50 formed integrally therein. The open first end 46 accepts an end cap 52 sized to close and/or seal the roughly cylindrical body 44. The end cap 52 includes a lip 56 which can be seated against a top edge 60 of the cylindrical body 44, and a cylindrical wall 58 sized to cooperate with the interior surface of the cylindrical body 44 such that the lip 56 and a top edge 60 of the cylindrical body 44 are in an abutting relationship. The cylindrical wall 58 and the cylindrical body 44 may be held together in a press-fit or friction arrangement, may include male and female threads and be rotatably joined and may be glued, welded or otherwise secured together in any desired manner. The end cap may further include an external, flat surface 54 arranged to bear against and/or bias the tip 40 of the sheath 34 when the snare 36 and catch 38 are retracted into the hollow interior 42. The flat surface 54 provides a firm contact between the two components, the removable filter head 16 and the snare catheter 32, and allows the transmission of forces therebetween.
The end cap 52 further includes an orifice 62 sized to slideably accept a rod portion 64 connected to the catch 38. The rod portion 64 extends through the orifice 62 into an interior 66 of the cylindrical body 44 to engage a stopper 70 having a contiguously formed shaft 68. The stopper 70, as shown in this exemplary embodiment, is a roughly cylindrical component sized to releasably engage the retainer 50 formed at the second end 48 of the cylindrical body 44. In operation, the stopper 70 is movable within the interior 66 of the cylindrical body 44 between a secured position adjacent to the retainer 50, and an unsecured position adjacent to the end cap 54.
The stopper 70 includes varying diameter portions that define a flange 72 and plug 74. The flange 74 and plug 74, of this present embodiment, are integral elements which are aligned coaxially with the shaft 68 and the rod portion 64. Physically, the flange 72 is a radially extending disc that compliments the interior 66 of the cylindrical body 44 and the plug 74 has a reduced diameter, relative to the flange 72, sized to cooperate with the retainer 50 when the stopper 70 is in the secured position. The shaft 68, as shown, may includes a blind bore 76 sized to securely accept the rod portion 64 in, for example, a threaded or press fit arrangement. The removable filter head 16 may further include a push nut 78 positioned adjacent to the cylindrical wall 58 of the end cap 52 to hold the stopper 70, via the shaft 68 and flange 72, in secure contact with the retainer 50.
A force applied through the catch 38 and rod portion 62 in the direction indicated by the arrow T allows the shaft 68 to elastically deform the push nut 78 and move the stopper 70 to the unsecured position adjacent 48 to the cylindrical wall 58 of the end cap 52. The cylindrical wall 58 and push nut 78 cooperate with the flange 72 to limit the overall movement of the stopper 70 to the unsecured position adjacent to the end cap 52. The shaft 68 further includes a reduced diameter portion 80 adjacent to the flange 72 and arranged to cooperate with the push nut 78 to, upon movement to the unsecured position at the open first end 46, prevent the stopper 70 and plug from reengaging the retainer 50.
The plug 74 and the retainer 50 cooperate to compressively engage and retain the superior ends 28 of the filter legs 20 when the stopper 70 is in the secured position. The superior end 28 of the filter legs 20 may be aligned within a plurality of grooves 82 (see
The movement of the stopper 70, in turn, causes the shaft 68 to bear against and elastically deform the push nut 78. In particular, the stopper movement elastically deforms the fingers, indicated by the numerals 78 a and 78 b, of the push nut 78. The elastically deformed fingers 78 a, 78 b ride along the shaft 68 and engage a reduced diameter portion 80 to prevent the stopper 70 from returning to the secured position adjacent to the retainer 50. Similarly, the flange 72 engages the cylindrical wall 58 and prevents additional movement or over-travel in the direction of the end cap 52. In this way, the stopper 70 is locked into the unsecured position away from the retainer 50 and between the end cap 52 and the retainer 50. The reduced diameter portion 80 may further act as a detent such that as the stopper 70 arrives at the unsecured position, it is engaged by the reduced diameter portion to retain it in the unsecured position. The action of the fingers sliding from the shaft 68 to the reduced diameter portion may also provide a haptic snap or click indication through the catheter, allowing the medical professional to know that the stopper 70 is fully retracted to the unsecured position.
The tension applied to retract the stopper 70 and elastically deform the push nut 78, can cause the entire convertible filter assembly 10 to move in order to react forces against the blood vessel wall 18. In order to limit force transfer to the vessel wall, the tension applied through the snare 36 is counteracted and balanced by an equal and opposite force applied to the flat surface 54 through the sheath 34. In this way, while the catch 38 and the attached stopper 70 are forced to disengage from the retainer 50, the counterforce applied through the sheath 34 maintains the position of the removable filter head 16 and attached filter elements 14, relative to the blood vessel wall 18.
As shown in
As outlined above, the process of transitioning the convertible filter assembly 10 begins with maneuvering and aligning the snare catheter 32 and the snare 36 with the removable filter head 16 and the catch 38. The aligned snare 36 engages the catch 38, and the sheath 34 is positioned in contact with the flat surface 54 of the end cap 52. In this way, the tip 40 of the snare catheter 32 abuts the removable filter head 16 (through contact with the end cap 52) and the sheath 34 encloses both the snare 36 and the catch 38.
Application of tension in the direction of the arrow T to the free end of the snare 36, e.g., the end of the snare 36 which is outside of the patient's body, pulls the catch 38 deeper into the sheath 34 and forces the attached stopper 70 to disengage from the retainer 50. It will be understood that unless the tension is greater than the force generated by the fingers 78 a, 78 b of the push nut 78 and the friction between the plug 74 and the retainer 50, the stopper 70 cannot be disengaged. Simultaneously, a counterforce can be applied to the removable filter head 16 through the sheath 34 in order to balance and counteract the effects of the tension applied through the snare 36. In other words, as the snare 36 is pulled to release the plug 74 from the retainer 50, the sheath 34 is pushed to engage the removable filter head 16 through the flat surface 54 of the end cap 52 and prevent movement relative to the blood vessel wall 18.
By overcoming the friction between the plug 74 and the retainer 50, the shaft 68 elastically deforms the fingers 78 a, 78 b of the push nut 78 and allows the stopper 70 to move away from the retainer 70 and to the unsecured position adjacent to the end cap 52. The fingers 78 a, 78 b, in turn, engage the reduced diameter portion 80 and lock or otherwise prevent the stopper 70 from reengaging the retainer 50. The movement of the stopper 70 is further limited, by the interference between the flange 72 and the cylindrical wall 58 of the end cap 52. This release mechanism within the removable filter head 16 allows the stopper 70 to be disengaged from the retainer 50 and prevents unwanted reengagement of the components.
Although certain embodiments have been described in accordance with the teachings of the present disclosure, the scope and coverage of this patent is not limited thereto. For instance, while the removable filter 14 has been illustrated and describes as having a cylindrical body, it will be understood that any desired shape or configuration may be employed. Further, while a specific embodiment of the intraluminal filter elements 14 has been described herein, many other single or double cone arrangements may be employed. This patent is intended to cover all embodiments of the teachings of the disclosure that fairly fall within the scope of the permissible equivalents.
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7704266||Jul 12, 2004||Apr 27, 2010||Rex Medical, L.P.||Vein filter|
|US7749246||Sep 2, 2005||Jul 6, 2010||Rex Medical, L.P.||Vein filter|
|US7909847||Sep 2, 2005||Mar 22, 2011||Rex Medical, L.P.||Vein filter|
|US8025675 *||Aug 14, 2008||Sep 27, 2011||Cook Medical Technologies Llc||Temporary filter device|
|US8057507||Jan 16, 2009||Nov 15, 2011||Novate Medical Limited||Vascular filter|
|US8162970||Jul 9, 2007||Apr 24, 2012||Novate Medical Limited||Vascular filter|
|US8298244 *||Sep 8, 2010||Oct 30, 2012||Tyco Healtcare Group Lp||Intracorporeal grasping device|
|US8366736||Oct 30, 2007||Feb 5, 2013||Rex Medical, L.P.||Vein filter|
|US8647360||Mar 22, 2012||Feb 11, 2014||Novate Medical Limited||Vascular filter|
|US8668713||Jan 15, 2010||Mar 11, 2014||Novate Medical Limited||Vascular filter device|
|US8821530||Oct 7, 2011||Sep 2, 2014||Novate Medical Limited||Vascular filter|
|US20100228281 *||Jan 15, 2010||Sep 9, 2010||Paul Gilson||Vascular filter system|
|US20100331853 *||Sep 8, 2010||Dec 30, 2010||Chestnut Medical Technologies, Inc.||Intracorporeal grasping device|
|US20120277787 *||Apr 28, 2011||Nov 1, 2012||Mitchell Donn Eggers||Vascular Filter Stent|
|Cooperative Classification||A61F2230/005, A61F2230/008, A61F2/01, A61F2002/011, A61F2002/016|
|Oct 19, 2006||AS||Assignment|
Owner name: B. BRAUN MEDICAL SAS, PENNSYLVANIA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:O CONNELL, PAUL A.;REEL/FRAME:018419/0674
Effective date: 20061013
|Oct 10, 2007||AS||Assignment|
Owner name: B. BRAUN MEDICAL SAS, FRANCE
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:O CONNELL, PAUL T.;NADAL, GUY;REEL/FRAME:019944/0865;SIGNING DATES FROM 20070523 TO 20071010