Method and devices for decreasing elevated pulmonary venous pressure

#The present invention relates to the implantation of one or more prosthetic valve(s) in the pulmonary vein(s) of a subject as a means of decreasing or preventing an increase in pulmonary venous pressure. The present invention accordingly provides novel strategies for the treatment of medical disorders associated with elevated pulmonary venous pressure, including congestive heart failure, as well as for prosthetic pulmonary vein valves and their delivery systems. Expandable as well as fixed-dimension non-expandable pulmonary vein prosthetic valves for implantation by a variety of surgical and percutaneous procedures are also described.

#Certain larger veins in the lower extremities of human beings normally have valves that, under conditions of normal function, permit movement of blood largely only toward the heart. In effect, properly functioning venous valves in the lower extremities protect, or partition, the veins of the lower extremities from the relatively high hydrostatic pressure of the column of venous blood between the right atrium and the lower extremities due to the effect of gravity during upright posture. Thus, normally, when upright posture is assumed, venous blood pressure in the foot is generally less than the sum of relatively low pressure in the right atrium and relatively high hydrostatic pressure of the column of venous blood between the right atrium and the foot due to the effect of gravity. When these venous valves in the lower extremities are incompetent, venous blood pressure in the foot becomes predominantly equal to the sum of the relatively low pressure in the right atrium and relatively high hydrostatic pressure of the column of venous blood between the right atrium and the foot, often resulting in pathologic dilatation of the veins in the lower extremities and/or edema.

#A prosthetic valve is an endoprosthesis typically formed of biological, synthetic or composite material, the final deployed diameter of which is suitable for implantation in the intended location in the heart or vascular conduits, such as arteries or veins. A prosthetic valve, when implanted and operating as intended, predictably directs the flow of blood through it. For example, a prosthetic aortic valve allows expulsion of blood from the left ventricle into the aorta during systole, and prevents reflux of blood into the left ventricle from the aorta during diastole. When used for replacement or repair of diseased native cardiac or vascular valves, prosthetic valves may relieve inappropriate obstruction to normally directed blood flow by narrowed or stenotic valves, or may restore appropriate hindrance to abnormally directed blood flow caused by leaking or regurgitant valves. Prosthetic valves are usually implanted by means of open surgical procedures, under general anesthesia and often with ventilatory and circulatory support, in which a surgeon exposes a diseased target valve to be replaced, resects and removes it, and implants an appropriate prosthetic valve in its place. Various types and designs of prosthetic valves for diverse clinical applications related to damage to and/or inappropriate function of the native cardiac valves have been described since the original report by Hufnagel et al.,1954, Surgery 35:573. A number of United States Patents have been issued relating to methods for percutaneous delivery of prosthetic valves and associated delivery methods, including, but not limited to, U.S. Pat. No. 5,332,402 by Teitelbaum, U.S. Pat. No. 5,397,351 by Pavenik et al., U.S. Pat. No. 5,607,465 by Camilli, U.S. Pat. No. 5,855,601 by Bessler et al., U.S. Pat. No. 5,163,953 by Vince, and U.S. Pat. No. 5,411,552 by Andersen et al.

#FIGS. 1A-D depict various views and embodiments of the diaphragm-type prosthetic pulmonary vein valve. (A) and (B) show, respectively, a transverse sectional view and a top view of a surgically implanted diaphragm valve, showing the valve positioned over an ostium of a pulmonary vein in the left atrium. (C) and (D) show, respectively, transverse sectional views of a diaphragm valve in open and closed positions, where the valve is held in place over a pulmonary vein ostium by an anchoring stent located in the pulmonary vein. The diaphragm valve has fenestrations, such that when the pressure in the pulmonary vein exceeds that of the left atrium, blood may flow through the fenestrations (C), but, when the pressure in the left atrium becomes greater than that in the vein (D), the occluder portion of the valve creates an obstruction to blood flow and/or the transmission of pressure into the pulmonary vein (D).

#FIGS. 2A-D depict various views and embodiments of the trapdoor-type prosthetic pulmonary vein valve. (A) and (B) show top views of surgically implanted trapdoor valves positioned over an ostium of a pulmonary vein in the left atrium. The valve shown in (A) is attached to the atrium by a hinge region surgically secured to the atrial wall; the “trapdoor” covers the ostium of a pulmonary vein and, in closed position, rests against the atrial wall. The valve shown in (B) is similar, but the point of attachment encircles the pulmonary vein ostium, such that when the “trapdoor” is in closed position, it rests, in part, against the outer circumference of the valve device. (C) and (D) show transverse sectional views of a valve of the species shown in (B), in closed and open positions, respectively.

#FIGS. 3A-B depict cut away views of a stocking-type prosthetic pulmonary vein valve, held in place in a pulmonary vein and extending into the left atrium, in open and closed positions, respectively.