INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

BACKGROUND

Patients who suffer heart failure frequently also experience renal failure, as renal failure can be caused by increased systemic venous congestion as a result of low cardiac output and low blood pressure. Such failure is called cardiorenal syndrome (CRS). Currently, heart failure patients are often treated pharmaceutically with diuretics in an attempt to decrease fluid overload (systemic venous congestion). However, during systemic venous congestion, there is lower-than-normal pressures on the arterial side and higher-than-normal pressures on the venous side of the kidneys. As a result, the kidneys are not able to clear the fluid overload using diuretics because there is not sufficient pressure differential across the kidneys. Accordingly, an alternative treatment for renal congestion is desired.

SUMMARY OF THE DISCLOSURE

Described herein are devices configured to help increase fluid flow through the kidneys and therefore aid in renal decongestion. Advantageously, the devices described herein can provide a mechanical solution to create a greater pressure gradient across the kidneys. This greater pressure gradient can allow improved renal function and/or a better renal response to diuretics.

In general, in one embodiment, a device for renal decongestion includes a hollow stent body having a first end and a second end, a first one-way valve at the first end of the hollow stent body, a second one-way valve at the second end of the hollow stent body, and a balloon configured to fit within the hollow stent body between the first one-way valve and the second one-way valve. The balloon is configured to repeatedly deflate to pull blood through the first one-way valve into the hollow stent body and inflate to push blood through the second one-way valve from the hollow stent body.

This and other embodiments can include one or more of the following features. The stent body can include a covering thereon. The balloon can be configured to be positioned within the hollow stent body after the hollow stent body is positioned within a blood vessel. The balloon can be configured to be positioned within the hollow stent body using a catheter with a guide wire positioned therein. The balloon can be configured to be positioned within the hollow stent body prior to the hollow stent body being positioned within a blood vessel. The balloon can be coupled with an inner surface of the hollow stent body. The balloon can be free-floating within the hollow stent body. The hollow stent body can be configured to transition between an expanded state and a collapsed state. The balloon can be configured to repeatedly deflate and inflate within the hollow stent body in the expanded state. A cross section diameter of the hollow stent body in the collapsed state can be suitably small for entry into a human blood vessel. The device can include an introducer sheath that is configured to constrain an outer diameter of the hollow stent body in the collapsed state. The introducer sheath can be configured to be retracted from the hollow stent body such that the hollow stent body can transition to the expanded state. The balloon can be configured to be repeatedly deflated and inflated by a fluid that is introduced via a catheter. The stent can be self-expandable. The balloon can be a first balloon, and the device can further include a second balloon configured to fit within the hollow stent body between the first one-way valve and the second one-way valve. The second balloon can be configured to repeatedly deflate to pull blood through the first one-way valve into the hollow stent body and inflate to push blood through the second one-way valve from the hollow stent body. The first balloon and the second balloon can be attached to an inner surface of the stent. The first balloon and the second balloon can be positioned along the inner surface of the stent approximately 180 degrees apart from one another. The first balloon and the second balloon can be configured to be inflated at the same time. The first balloon and the second balloon can be configured to touch one another within the stent when inflated. The balloon can be an integral part of a liner positioned along an inner circumference of the hollow stent body.

In general, in one embodiment, a method of decongesting a kidney includes: (1) inserting a device within a blood vessel, the device including a hollow stent body having a first end and a second end, a first one-way valve at the first end of the hollow stent body, a second one-way valve at the second end of the hollow stent body, and a balloon configured to fit within the hollow stent body between the first one-way valve and the second one-way valve; and (2) increasing a pressure differential across the kidney by repeatedly deflating the balloon to pull blood through the first one-way valve into the hollow stent body and inflating the balloon to push blood from the hollow stent body through the second one-way valve.

This and other embodiments can include one or more of the following features. Inserting the device within the blood vessel can include inserting the device within an aorta, a vena cava, a renal artery or a renal vein. Inserting the device within the blood vessel can include inserting the hollow stent body into place within the blood vessel and inserting the balloon into the hollow stent body after inserting the hollow stent body. Inserting the balloon can include guiding the balloon through the blood vessel and within the hollow stent body using a catheter coupled to the balloon and a guide wire threaded within the catheter. Inserting the device within the blood vessel can include inserting the hollow stent body with the balloon positioned therein into the blood vessel. Increasing a pressure differential across the kidney by repeatedly deflating the balloon to pull blood through the first one-way valve into the hollow stent body and inflating the balloon to push blood from the hollow stent body through the second one-way valve can include supplying and removing a fluid to and from the balloon with a catheter. Inserting a device within a blood vessel can include inserting the device into the descending aorta so as to decrease afterload on a left ventricle by decreasing pressure at the first end of the hollow stent body.

In general, in one embodiment, a device for renal decongestion includes a hollow covered stent body having a first end and a second end, a first one-way valve, a second one-way valve, and a balloon. The first one-way valve is at the first end of the hollow stent body. The second one-way valve is at the second end of the hollow stent body. The balloon is within the hollow covered stent body between the first one-way valve and the second one-way valve. The balloon is configured to repeatedly deflate to pull blood through the first one-way valve into the hollow stent body and inflate to push blood through the second one-way valve from the hollow stent body in an antegrade direction.

This and any other embodiments can include one or more of the following features. The balloon can be an integral part of a liner positioned along an inner circumference of the hollow stent body. The liner can be sealed at proximal and distal edges of the hollow stent body. The liner can be positioned along the entire inner circumference of the hollow covered stent body. The device can further include an inflation lumen terminating proximate to the liner. The balloon can be configured to inflate at a frequency of at least 0.5 to 3 times a normal heart rate. The balloon can be configured to inflate at a frequency of about 30-180 inflations and deflations per minute. The device can further include a catheter connected to the hollow covered stent body. The device can further include an occlusion balloon positioned along the catheter. The hollow covered stent body can be configured to transition between an expanded state and a collapsed state. The inflated balloon can include a plurality of lobes.

In general, in one embodiment, a method of decongesting a kidney includes: (1) inserting a device within a blood vessel, where the device includes a hollow covered stent body having a first end and a second end, a first one-way valve at the first end of the hollow covered stent body, a second one-way valve at the second end of the hollow covered stent body, and a balloon within the hollow covered stent body between the first one-way valve and the second one-way valve; (2) increasing antegrade flow through the kidney by repeatedly deflating the balloon to pull blood through the first one-way valve into the hollow covered stent body; and (3) inflating the balloon to push blood from the hollow covered stent body through the second one-way valve.

This and other embodiments can include one or more of the following features. The balloon can be an integral part of a liner positioned along an inner circumference of the hollow covered stent body. Inflating the balloon can include providing inflation fluid between the liner and the inner circumference of the hollow covered stent body. Increasing a flow rate of blood through the kidney by repeatedly deflating the balloon to pull blood through the first one-way valve into the hollow covered stent body and inflating the balloon to push blood from the hollow covered stent body through the second one-way valve can include supplying and removing a fluid to and from the balloon with a catheter. Inflating the balloon can substantially fill a lumen of the hollow covered stent. The method can further include inflating an occlusion balloon within the blood vessel to restrict a flow of blood through the blood vessel while repeatedly deflating and inflating the balloon. The method can further include positioning the occlusion balloon within the blood vessel such that it is on an opposite side of the kidney than the hollowed covered stent body. Inserting the device within the blood vessel can include inserting the device within an aorta, a vena cava, a renal artery or a renal vein. Inserting a device within a blood vessel can include inserting the device into the descending aorta so as to decrease afterload on a left ventricle by decreasing pressure at the first end of the hollow covered stent body. The method can further include removing the device from the blood vessel after increasing antegrade flow.

