PERCUTANEOUS HEART VALVE DEVICES
The invention includes a medical device and more specifically relates to a valve found generally within a frame. In a preferred device, the frame preferably comprises a self-expanding stent frame, and the valve has at least one expandable and contractible pocket member within the stent frame for resisting and permitting fluid flow, respectively.
This is a continuation of U.S. patent application Ser. No. 10/837,058, filed on Apr. 30, 2004, pending, which is a continuation of U.S. patent application Ser. No. 10/457,148, filed on Jun. 9, 2003, pending, which is a continuation of U.S. patent application Ser. No. 10/182,970, filed on filed Jan. 31, 2001, abandoned, which is an National Stage of PCT/US/01/03095, filed on Jan. 31, 2001 and published in English, which claims the benefit of U.S. Provisional Patent Application No. 60/179,195, filed on Jan. 31, 2000.
BACKGROUND OF THE INVENTION1. Technical Field of the Invention
The invention includes a medical device and more specifically to a valve found generally within a frame. In preferred devices the frame is comprised of a radially expandable stent which can be delivered through a delivery device such as a catheter.
2. Background of the Invention
Lower extremity venous hypertension in addition to venous insufficiency is a major cause of morbidity in the United States. Symptoms of venous disease include lower extremity edema, varicosities, skin pigmentation changes, skin ulceration, and general poor circulation. One solution to this problem is to replace the defective valve or the vein with a valve assembly.
Current valves include a pressure responsive, pressure directed ball movement valve assemblies. The problem with mechanical ball valves is that mechanical valves are susceptible to clot formation. Additionally, there are problems associated with long-term wear and tear on the device.
Artificial valves such as biological valves are also known. Biological valves include homografts, allografts, and xenografts. Problems associated with some biological valves include the supply of the valves, immunity response, or problems associated with matching the size with the donor.
Finally other problems associated with valve repair include placement problems in which the device cannot be repositioned once it is ejected from the placement catheter, leakage that occurs, around the valve, and emboli formation.
In light of this background, there remains a need for alternative and improved devices and methods for providing valvular function within vessels of the body. The present invention is addressed to these needs.
SUMMARY OF THE INVENTIONDisclosed is a medical device comprising a frame that has a valve generally located within. In preferred forms of the invention, the frame is comprised of a radially-expandable stent (including especially a self-expanding stent), which can be delivered through a delivery device such as a catheter, and then deployed and expanded at a target site in a body lumen such as an artery or vein. For example, in one preferred use, such a stent and method are used to treat incompetent veins in the legs or feet.
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The valve material 38 can be any biocompatible material such as polyethylene terephalate(PET), polypropylene(PP), polytetrafluorethylene(-PTFE), or any polymer or derivative thereof, and also includes commercially known materials such as GORE-TEX, DACRON, or any other synthetic material. The preferred material 38 will be advantageously compliant and employed so as to permit effective value function as described herein and in the case of collapsible/expandable state devices will retain integrity and function when cycled between these states.
It is preferred to use a biomaterial that serves as a biocompatible scaffold with the ability to remodel host tissue. Accordingly, a naturally occurring biomaterial is highly desirable. One such biomaterial is collagen and more particularly, a collagen based biomaterial called extracellular matrix (ECM). Examples of ECM's include pericardium, stomach submucosa, liver basement membrane, urinary bladder submucosa, tissue mucosa, dura mater, and small intestine submucosa One such biomaterial is the ECM, such as submucosa, and more particularly is small intestine submucosa (SIS). SIS can be made in the fashion described in Badylak et al., U.S. Pat. No. 4,902,508; Intestinal Collagen Layer described in U.S. Pat. No. 5,733,337 to Carr and in 17 Nature Biotechnology 1083 (November 1999); Cook et al., WIPO Publication WO 98/22158, dated May 28, 1998, which is the published application of PCT/US97/14855; Gastric Submucosa as described in WO 98/26291 (PCT/US97/22729), claiming priority to U.S. Provisional application No. 60/032,686; Liver tissue as described in WO 98/25637 (PCT/US97/22727), claiming priority to 60/032,680; Stomach Submucosa as described in WO 98/25636 (PCT/US97/23010), claiming priority to 60/032,683; and Urinary Bladder Submucosa as described in U.S. Pat. No. 5,554,389; all the disclosures of which are hereby expressly incorporated by reference. Irrespective of the origin of the valve material (synthetic versus naturally occurring), the valve material can be made thicker by making multilaminate constructs, for example SIS constructs as described in U.S. Pat. Nos. 5,968,096; 5,955,110; 5,885,619; and 5,711,969; the disclosures of which are entirely and expressly incorporated by reference.
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The valve opening 52 although already described above, is actually created in the final step of preparation of the preferred device manufacture. The construction mentioned above would be repeated on the other side of the valve to create the valve pocket 46, valve apex 50, and the like on the other side. At this point, though, there is no valve opening 52. The valve opening 52 is created by creating a slit in the sheet to create the opening. The slit can be sized according to the intended flow rate of the passing fluid. Accordingly, a large slit would create a large valve opening or orifice and permits a large volume of fluid to pass therethrough. The slit can be created by poking a scalpel through it and running it to the desired length. However, due to potential fatigue at the orifice, another set of reinforcements may be added to the orifice perimeter. Therefore, as shown in
Therefore, the stent valve as constructed can be using one stent with the valve material enclosed therein. Of course in the single stent configuration, the overall length can be adjusted by elongating the length of the struts 24. However, devices of the invention can be built using a plurality of stents to elongate the overall size of the stent, if desired. In this regard, it will be preferred that the length of the device 20 is sufficient to provide an aspect ratio (length to expanded diameter) sufficiently high to facilitate proper alignment of the device 20 within the vessel, with the axis of the device lumen generally aligned with the axis of the vessel. For example, devices having a ratio of length:expanded diameter of 1:1 or greater, or about 2:1 or greater, will be preferred. It will be understood that while such dimensions will advantageously facilitate placement of the inventive devices, they are not necessary to the broader aspects of the invention.
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Manufacture of the multi-stent or multi-valve device will generally follow the same construction as described above. The same considerations in making a single valve single stent device applies equally to the elongated device.
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As described earlier, the excess material can either be trimmed off or folded over the outer surface of the device. Shown in
In all embodiments of the invention, the external surface of the frame can be covered with a sheath that is not necessarily the same material as the valve 41. For example, while the valve can be a naturally occurring material, the outer sheath can be synthetic material such as described herein. The sheath, therefore, can be the fold-over of the valve material, another type of naturally occurring material, or a synthetic material. Accordingly, the sheath may partially or totally cover the frame.
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The vessel 80 has an inner lumenal surface 82 in which the fluid flows. The fluid flow path is shown as fluid path 70. Vessel 80 also has a vessel diameter 84. The medical device, upon implantation, will also have a device outer stent diameter 86. The outer diameter 86 will be chosen to permit contact with the inner lumenal surface 82. The optimized fit will decrease the leakage around the device by contacting the inner lumenal surface 82. A tight fit can be accomplished by sizing the stent diameter to be greater than the vessel diameter. For example, a stent diameter that is about 110 percent greater than (i.e. 1.1 times) the vessel diameter provides a good fit. Expanded stent diameters of about 10 mm to about 30 mm will be typical in many applications of the present invention. Again, while it is shown in this
The standard method of deploying the medical device 20 in a vessel 80 involves the use of a medical assembly (see
Finally, since the device is located in an in vivo environment, the device may be treated with therapeutic agents to facilitate healing. For example, the frame may be treated with therapeutic agents such as anticancer drugs, plaque busters, anti-coagulants, or the like. Similarly, the valve material can be treated with therapeutics agents such as anti-cancer drugs, plaque busters, anti-coagulants, proteins, growth factors, proteoglycans, and the like. Furthermore, radiopaque agents may be added, such as tantalum, barium, bismuth, or the like to increase radiopacity. These ingredients can be bonded to the frame or the valve material such as rubbing the agent in, bonding it, adhering it, or the like.
While the invention has been illustrated and described in detail in the drawings and the foregoing text, it is understood that these are only some embodiments and that the scope of the invention is not solely defined by the description herein but also by the appended claims. All modifications and changes that come within the spirit of the invention are hereby protected.
Claims
1. A percutaneous heart valve device, comprising:
- a self-expandable frame having a first condition suitable for percutaneous vascular delivery to a vascular site for providing a heart valve, and a second, expanded condition adapted for deployment at the vascular site,
- said expanded condition providing an inner lumen and including a first frame end and a second frame end, said first frame end having a perimeter of a different length than the perimeter of said second frame end; and
- a plurality of flexible valve leaflets located within the inner lumen of said frame, said plurality of flexible valve leaflets comprised of pericardium and each having a proximal end and a distal end, said leaflet proximal ends having cooperating leaflet edge portions having outer ends connected to said frame at a first intermediate location along the length of said frame, said leaflet edge portions extending inwardly from said frame and associating to provide a valve orifice within the lumen of said frame,
- said plurality of flexible valve leaflets extending only partially along the length of said frame, wherein said leaflet distal ends are spaced proximally from an inlet end of said heart valve device, and each include a leaflet apex attached to said frame with a plurality of sutures extending in a generally lateral direction around a portion of the circumference of said frame, said leaflet apexes attached to said frame at a second intermediate location along the length of said frame, said second intermediate location spaced distally from said first intermediate location along said frame.
2. A percutaneous heart valve device, comprising:
- a self-expandable frame having a first condition suitable for percutaneous vascular delivery to a vascular site for providing a heart valve, and a second, expanded condition adapted for deployment at the vascular site,
- said expanded condition providing an inner lumen and including a longitudinal frame segment having a generally cylindrical shape, said longitudinal frame segment providing a first end and a second end, said first end providing an inlet end of the heart valve device; and
- a valve arrangement residing within the inner lumen of said frame, said valve arrangement comprising a material in sheet-form and including a plurality of flexible valve leaflets each having a proximal end and a distal end, said leaflet proximal ends having cooperating leaflet edge portions having outer ends connected to said frame at a first intermediate location along the length of said frame, said leaflet edge portions extending inwardly from said frame and associating to provide a valve orifice within the lumen of said frame,
- said plurality of flexible valve leaflets extending only partially along the length of said frame, wherein said leaflet distal ends are spaced proximally from said first end of said longitudinal frame segment, and each include a leaflet apex attached to said frame with a plurality of sutures extending in a generally lateral direction around a portion of the circumference of said longitudinal frame segment, said leaflet apexes attached to said frame at a second intermediate location along the length of said frame, said second intermediate location spaced distally from said first intermediate location along said frame.
3. The percutaneous heart valve device of claim 2, wherein said material in sheet form includes a flexible collagenous biomaterial.
4. The percutaneous heart valve device of claim 3, wherein said flexible collagenous biomaterial comprises a tissue material selected from the group consisting of pericardium, small intestine submucosa, stomach submucosa, urinary bladder submucosa, and dura mater.
5. The percutaneous heart valve device of claim 3, wherein said flexible collagenous biomaterial comprises pericardium.
6. The percutaneous heart valve device of claim 2, wherein said material in sheet form comprises a synthetic polymeric material.
7. The percutaneous heart valve device of claim 2, wherein said material in sheet form includes material portions connected to said frame at the inlet end of the heart valve device.
8. A percutaneous heart valve device, comprising:
- a self-expandable frame having a first condition suitable for percutaneous vascular delivery to a vascular site for providing a heart valve, and a second, expanded condition adapted for deployment at the vascular site,
- said expanded condition providing an inner lumen and including a longitudinal frame segment having a generally cylindrical shape, said longitudinal frame segment providing a first end and a second end, said first end providing an inlet end of the heart valve device; and
- a plurality of flexible valve leaflets located within the inner lumen of said frame, said plurality of flexible valve leaflets comprised of pericardium and each having a proximal end and a distal end, said leaflet proximal ends having cooperating leaflet edge portions having outer ends connected to said frame at a first intermediate location along the length of said frame, said leaflet edge portions extending inwardly from said frame and associating to provide a valve orifice within the lumen of said frame,
- said plurality of flexible valve leaflets extending only partially along the length of said frame, wherein said leaflet distal ends are spaced proximally from said first end of said longitudinal frame segment, and each include a leaflet apex attached to said frame with a plurality of sutures extending in a generally lateral direction around a portion of the circumference of said longitudinal frame segment, said leaflet apexes attached to said frame at a second intermediate location along the length of said frame, said second intermediate location spaced distally from said first intermediate location along said frame.
9. The percutaneous heart valve device of claim 8 having two flexible valve leaflets.
10. The percutaneous heart valve device of claim 8 having three flexible valve leaflets.
11. The percutaneous heart valve device of claim 8, wherein said outer ends of said cooperating leaflet edge portions are connected to said frame with sutures.
12. The percutaneous heart valve device of claim 8, wherein said frame provides an inner frame surface, said cooperating leaflet edge portions sutured together in regions bounding said valve orifice and said valve orifice terminating before reaching said inner frame surface.
13. The percutaneous heart valve device of claim 8, further comprising a covering material covering an outer surface of said frame.
14. The percutaneous heart valve device of claim 13, wherein said covering material includes a portion extending circumferentially around said frame.
15. The percutaneous heart valve device of claim 14, wherein said covering material includes a portion extending partially along the length of said frame.
16. The percutaneous heart valve device of claim 13, wherein said covering material comprises a synthetic polymeric material.
Type: Application
Filed: Feb 20, 2008
Publication Date: Jun 26, 2008
Inventors: Joseph F. Obermiller (West Lafayette, IN), Francisco Jose Osse (Sao Paulo), Patricia E. Thorpe (Omaha, NE)
Application Number: 12/034,290