Flow-limiting stent graft

Abstract

Various aspects of the present invention relate to devices, systems and methods for modifying blood flow in a patient's blood vessel. These devices, systems and methods may include: one or more anchoring portions; a flow restriction portion having a reduced diameter section relative to the one or more anchoring portions; and a diaphragm member coupled to at least a portion of the flow restriction portion.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Provisional Patent Application No. 62 / 702,700, filed on July 24, 2018, which is incorporated herein by reference in its entirety for all purposes. Technical Field

[0003] The present disclosure relates to systems, medical devices and methods for treating heart failure and / or other cardiovascular diseases. More specifically, the present disclosure relates to removing the accumulation of excess fluid that is often caused by poorly perfused kidneys. Background Art

[0004] Patients experiencing heart failure may accumulate excess fluid in their bodies. Excessive fluid accumulation may increase fluid accumulation in the interstitial spaces and worsen the patient's symptoms and quality of life. Excess fluid (or hypervolemia) is the leading cause of hospitalization for heart failure patients (approximately 1,000,000 cases per year in the United States).

[0005] Treatment of excess fluid accumulation can be treated pharmaceutically with diuretics (or other agents). However, patients may develop drug resistance, undesirable side effects, inappropriate dosages, or other problems such as failure to follow drug instructions. Non-drug options such as implantable device solutions that provide replacement or enhanced efficacy by affecting renal function can be beneficial to avoid these and other problems in treating excessive fluid accumulation in the body. Similarly, chronic hypertension (high blood pressure) can also be managed pharmaceutically with diuretics (or other antihypertensive agents). In addition, other disease states may lead to hypotension, reduced cardiac output, and poor renal function. As long as the kidneys play a central role in regulating systemic blood pressure and fluid homeostasis, non-drug options such as implantable device solutions that provide replacement or enhanced efficacy by affecting renal function can provide alternative methods to manage fluid imbalances caused by chronic disease states such as heart failure, hypertension, and other disease states. Summary of the invention

[0006] In one example ("Example 1"), an implantable medical device for altering blood flow in a patient's blood vessel includes: one or more anchoring portions configured to contact a vessel wall of the blood vessel; a flow-restricting portion having a reduced diameter section relative to the one or more anchoring portions; and a diaphragm component connected to at least a portion of at least one of the flow-restricting portions and configured to increase flow resistance within the main blood vessel and increase blood flow into one or more side branches that branch off (leave the blood vessel / deviate from the blood vessel / extend from the blood vessel) from the blood vessel.

[0007] In another example ("Example 2") that is further advanced relative to the device of Example 1, the diaphragm component is configured to increase blood flow into one or more side branches that branch off from the blood vessel (leave the blood vessel / deviate from the blood vessel) by between about 5% and about 30%, and the side branches are proximal to the flow restricting portion.

[0008] In another example ("Example 3") that is further than the device of any of Examples 1-2, one or more anchoring portions include a first anchoring portion and a second anchoring portion, and the flow limiting portion forms an hourglass shape, and the flow limiting portion tapers inwardly to reduce the diameter of one or more of the first anchoring portion and the second anchoring portion.

[0009] In another example ("Example 4") further than the apparatus of Example 3, the diaphragm member is coupled to one of the first anchor portion and the second anchor portion, and the other of the first anchor portion and the second anchor portion is uncovered.

[0010] In another example ("Example 5") further than the apparatus of Example 4, a membrane member is coupled to the first anchor portion to at least partially cover the first anchor portion to restrict blood flow lateral to the first anchor portion.

[0011] In another example ("Example 6") that is further related to the device of Example 5, the second anchoring portion is uncovered and is configured to allow blood flow laterally through the second anchoring portion.

[0012] In another example ("Example 7") further than the apparatus of Example 6, the second anchoring portion is configured to reduce the likelihood of occluding one or more side branches exiting (dividing from / departing from / extending from) the blood vessel.

[0013] In another example ("Example 8") further related to the apparatus of any of Examples 5-6, wherein the septum member is coupled to the first anchor portion at a location where the first anchor portion is configured to contact a vessel wall.

[0014] In another example ("Example 9") that is further related to the apparatus of Example 8, the position of the septum component on the first anchoring portion is configured to reduce thrombosis.

[0015] In another example ("Example 10") that is further relative to the device of any of Examples 1-9, the blood vessel is the patient's aorta and the side branches are one or more of the renal arteries, the celiac arteries, the hepatic arteries, and the mesenteric arteries, and the implantable medical device is configured to be implanted in the aorta and increase blood flow into one or more of the renal arteries, the celiac arteries, the hepatic arteries, and the mesenteric arteries.

[0016] In another example ("Example 11") further than the apparatus of Example 10, the diaphragm component is configured to increase the blood pressure at the mouth of at least one renal artery relative to the venous outflow pressure and to increase the pressure across the patient's kidney, thereby causing more blood to flow through the kidney.

[0017] In another example ("Example 12") further than the apparatus of Example 11, the diaphragm component is configured to increase blood pressure at the ostium of at least one renal artery, which facilitates an increase in fluid filtered by the kidneys, thereby increasing diuresis and reducing fluid retention in the patient.

[0018] In another example ("Example 13") further than the apparatus of any of Examples 1-12, the membranous member is configured to cause between about 40% and about 80% stenosis of the vessel distal to the one or more side branches.

[0019] In another example ("Example 14") further than the apparatus of Example 13, the membranous member is configured to cause between 50% and 70% stenosis of the vessel distal to the one or more side branches.

[0020] In another example ("Example 15") that is further than the device of any of Examples 1-14, one or more anchoring portions are configured to abut against a vessel wall in the vena cava and the diaphragm component is configured to form a narrowed flow lumen of between about 40% and about 90% of the vena cava distal to one or both of the renal veins to facilitate blood flow out of the kidneys.

[0021] In one example ("Example 16"), an implantable medical device for altering blood flow within a patient's blood vessel includes: a flow-restricting section that substantially blocks blood flow laterally through the implantable medical device and reduces the diameter to longitudinally restrict blood flow within the vessel; and an opening section that is configured to allow blood to flow laterally through the implantable medical device.

[0022] In another example ("Example 17") that is further than the device of Example 16, the flow limiting section also includes a diaphragm component that is configured to increase flow resistance within the blood vessel and increase blood flow into one or more side branches that branch off from the blood vessel (leave the blood vessel / deviate from the blood vessel / extend from the blood vessel).

[0023] In another example ("Example 18") that is further than the device of Example 16, the opening segment is configured to promote blood flow into one or more side branches that branch off from (leave the blood vessel / deviate from the blood vessel / extend from the blood vessel) without blocking one or more side branches that branch off from (leave the blood vessel / deviate from the blood vessel / extend from the blood vessel).

[0024] In one example ("Example 19"), a method for changing blood flow in a patient's blood vessel includes: delivering an implantable medical device, the implantable medical device including a flow-restricting segment and an opening segment, the flow-restricting segment substantially blocking blood flow laterally through the implantable medical device and reducing the diameter to longitudinally restrict blood flow in the blood vessel, and the opening segment being configured to allow blood to flow laterally through the implantable medical device; and configuring the opening segment of the implantable medical device to at least partially overlap one or more side branches branching off (leaving the blood vessel / deviating from the blood vessel / extending from the blood vessel) from the blood vessel to allow blood flow to be perfused into the one or more side branches.

[0025] In another example ("Example 20") that is further than the method of Example 19, setting an opening section of the implantable medical device includes setting a closed section of the implantable medical device, which is located distally or proximal to one or more side branches that branch off from (leave the blood vessel / deviate from the blood vessel / extend from the blood vessel).

[0026] The foregoing examples are merely, and should not be construed as limiting or otherwise narrowing the scope of any inventive concept provided by the present disclosure. Although a number of examples are disclosed, other examples will become apparent to those skilled in the art from the following detailed description, which illustrates and describes illustrative examples of the present invention. Therefore, the drawings and detailed description should be considered to be illustrative in nature and not restrictive in nature. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification, illustrate embodiments, and together with the description serve to explain the principles of the present disclosure.

[0028] Figure 1 Exemplary implantable medical devices according to various aspects of the present disclosure are shown.

[0029] Figure 2 Exemplary implantable medical devices according to various aspects of the present disclosure are shown.

[0030] Figure 3A-3B An exemplary implantable medical device according to various aspects of the present disclosure is shown implanted in the vasculature of a patient.

[0031] Figure 4 Another exemplary implantable medical device according to various aspects of the present disclosure is shown implanted in a patient's blood vessel. DETAILED DESCRIPTION

[0032] Definitions and terminology

[0033] This disclosure is not intended to be read in a limiting manner. For example, the terms used in this application should be read broadly in the context of the meanings that those skilled in the art would attribute to such terms.

[0034] With respect to imprecise terms, the terms "about" and "approximately" are used interchangeably to refer to a measurement value that includes the measurement value and also includes any measurement value that is reasonably close to the measurement value. As understood and easily determined by a person of ordinary skill in the relevant art, a measurement value that is reasonably close to the measurement value deviates from the measurement value by a relatively small amount. Such deviations may be attributed to, for example, measurement errors, differences in the measurement values ​​and / or calibration of manufacturing equipment, human errors in reading and / or setting the measurement values, fine-tuning to optimize performance and / or structural parameters in view of differences in the measurement values ​​associated with other components, specific implementation scenarios, imprecise adjustment and / or manipulation of the object by a person or machine, and / or the like. If it is determined that a person of ordinary skill in the relevant art would not easily determine the value of such a reasonable small difference, the terms "about" and "approximately" may be understood to be plus or minus 10% of the value.

[0035] Description of various embodiments

[0036] Those skilled in the art will readily appreciate that various aspects of the present invention may be implemented by any number of methods and devices configured to perform the intended functions. It should also be noted that the drawings referenced herein are not necessarily drawn to scale, but may be exaggerated to illustrate various aspects of the present disclosure, and in this regard, the drawings should not be construed as limiting.

[0037] Various aspects of the present disclosure relate to treating heart failure and / or other cardiovascular diseases such as hypertension and hypotension in patients. In some cases, the patient's condition may worsen due to the accumulation of excessive fluid (e.g., hypervolemia) in the body. The accumulation of fluid may mainly increase fluid accumulation in tissues and increase fluid and pressure in various circulations and organs. The increased fluid and pressure in the tissues and themselves or in combination with the already failing heart may further harm the patient. As discussed in further detail below, various aspects of the present disclosure relate to reducing the accumulation of excess fluid by using an implantable medical device.

[0038] Various aspects of the present disclosure relate to implantable medical devices configured to manipulate renal blood flow hemodynamics to cause a physiologically mediated therapeutic response. In some cases, the implantable medical devices discussed herein are intended to increase natural diuresis and reduce the accumulation of excess fluid by increasing blood flow to the kidneys. Through this action, the device is configured to redirect blood flow to the kidneys to reperfuse the kidneys, improve diuresis (increase fluid removal) and minimize / eliminate the effects of excessive fluid on the heart. Renal health can include the amount of damage maintained, maintained, or reduced in function by the kidney relative to the baseline renal function of the patient when healthy. In some cases, renal injury can be quantified by measuring neutrophil gelatinase-associated lipocalin (NGAL).

[0039] In some cases, an implantable medical device can achieve sustained and controlled fluid removal. As described below, the vasculature near a patient's renal arteries is complex. More specifically, a patient's vasculature may include side branches of the aorta in addition to the renal arteries. The implantable medical device may include a graft attached to at least a portion of a stent. The graft may be attached to only a portion of the stent to allow blood flow through the implantable medical device. The open or uncovered stent portion allows blood to flow therethrough to enable the device to be positioned without accidentally blocking the side branch vessels.

[0040] In some cases, the implantable medical devices discussed herein can be implanted in other blood vessels. The implantable medical device can promote an increase in peripheral resistance to treat a decrease in blood pressure or a decrease in resistance within the vasculature. As discussed further below, this can include implantation of an implantable medical device for treating an arteriovenous (AV) fistula.

[0041] Figure 1 An exemplary implantable medical device 100 is shown in accordance with various aspects of the present disclosure. Implantable medical device 100 is shown disposed within the vasculature of a patient. Figure 1 The vasculature of the patient shown in FIG. 1 includes the patient's heart 102, aortic root 104, superior vena cava 106, aortic arch 108, pulmonary trunk 110, descending aorta 112, celiac artery 114, superior mesenteric artery 116, renal arteries 118, 120, inferior mesenteric artery 122, abdominal aorta 124, and iliac arteries 126, 128. The implantable medical device 100 may be disposed in the aorta distal to the renal arteries 118, 120. Furthermore, the implantable medical device 100 may be configured to increase blood flow into at least one of the renal arteries 118, 120 while maintaining substantially unrestricted blood flow in the aorta proximal to the renal arteries 118, 120. Furthermore, in addition to or in lieu of the implantable medical device 100 disposed in the aorta distal to the renal arteries 118, 120, the implantable medical device 100 may be disposed in one or both of the iliac arteries 126, 128.

[0042] In some cases, the implantable medical device 100 can be used to enhance perfusion of branch vessels originating from the aorta (e.g., the renal arteries 118, 120 or the iliac arteries 126, 128). The implantable medical device 100 can be adjusted to increase blood flow into the branch vessels by increasing the resistance to blood flow through the implantable medical device 100 to increase the pressure within the aorta. In addition, the implantable medical device 100 can be configured to remain in the aorta to continuously increase perfusion.

[0043] An implantable medical device 100 configured to increase blood flow into at least one of the renal arteries 118, 120 can reduce fluid accumulation by increasing the amount of blood filtered by the kidneys. In patients with heart failure, insufficient blood flow through the kidneys due to impaired cardiac output and venous congestion can (at least in part) cause fluid overload. Using an implantable medical device 100 to increase blood flow into at least one renal artery 118, 120 can increase renal perfusion hemodynamically rather than pharmacologically. In order to achieve increased renal perfusion, resistance to blood flow distal to the renal arteries 118, 120 can be increased, which can reduce distal perfusion. Increased renal perfusion enhances renal filtration and thus removes fluid volume. In addition, the implantable medical device 100 can be used to enhance the performance of pharmacological treatments associated therewith. For example, pharmacological treatments (e.g., diuretics and / or hypertension medications) can be enhanced by additionally enhancing the patient's renal function.

[0044] In some cases, an implantable medical device 100 configured to increase blood flow into at least one of the renal arteries 118, 120 while maintaining substantially unrestricted blood flow in the aorta proximal to the renal arteries 118, 120 can focus blood flow into one or both of the renal arteries 118, 120. The restriction proximal to the renal arteries 118, 120 can direct blood flow to other areas supplied by the aorta, such as the celiac artery 114, the superior mesenteric artery 116, or the brain. Thus, in some cases, the implantable medical device 100 can be disposed in the patient's aorta distal to (or overlapping with) the renal arteries 118, 120. The result can be increased blood flow to at least one kidney by increasing blood flow to one or both of the renal arteries 118, 120, which can increase fluid removal from the circulation, which will alleviate fluid and pressure accumulation in various circulations and organs.

[0045] Implantable medical device 100 provides a non-drug method to increase urine production (diuresis) and / or change systemic blood pressure. Patients may experience drug resistance, inaccurate dosage or undesirable side effects. When drugs fail, water replacement therapy or hemodialysis can be used to filter fluid directly from the blood, however, these solutions are relatively invasive and destructive to the patient's lifestyle and mobility. In addition, water replacement therapy or hemodialysis may also produce hemodynamic instability, with associated cardiovascular complications, renal injury, infection and / or require capital (expensive) equipment.

[0046] The implantable medical device 100 can change the peripheral resistance when implanted percutaneously or surgically, temporarily or permanently, and can be adjustable to meet the needs of the patient. The implantable medical device 100 can remain in the body after implantation as long as the patient requires intervention. The implantable medical device 100 can be implanted for hours, days, or even years.

[0047] Figure 1 The illustrative implantable medical device 100 shown in is not intended to suggest any limitation as to the scope of use or functionality of the embodiments of the present disclosure disclosed in this document. Nor should the illustrative implantable medical device 100 be interpreted as having any dependency or requirement relating to any single component or combination of components shown therein. Furthermore, in various embodiments, Figure 1 Any one or more of the components depicted in the figures may be integrated with various other components depicted in the figures (and / or components not shown).

[0048] Figure 2 An exemplary implantable medical device 200 according to various aspects of the present disclosure is shown. The implantable medical device 200 is configured to alter blood flow in a patient's blood vessel. The implantable medical device 200 may include one or more anchoring portions, including a first anchoring portion 202 and a second anchoring portion 212. The first anchoring portion 202 and the second anchoring portion 212 may include a stent element. In addition, the implantable medical device 200 may include a flow restriction portion 206 having a reduced diameter section relative to the anchoring portions 202, 212. Figure 2 As shown, the flow restriction portion 206 tapers inwardly from one of the anchoring portions 202, 212. In some cases and as Figure 2 As shown, the anchoring portions 202, 212 and the flow restricting portion 206 form an hourglass shape.

[0049] The implantable medical device may further include a diaphragm member 204 coupled to at least a portion of the flow-restricting portion 206. Figure 3A-3B and Figure 4As further explained in detail, the diaphragm member 204 can be configured to increase flow resistance within the blood vessel and increase blood flow into one or more side branches branching off (leaving the blood vessel / deviating from the blood vessel / extending from the blood vessel) from the blood vessel. The diaphragm member 204 can be configured to increase blood flow into one or more side branches branching off (leaving the blood vessel / deviating from the blood vessel) from the blood vessel by between about 20% and about 30%. In addition, the diaphragm member 204 is coupled to one of the first anchor portion 202 and the second anchor portion 212, and the other of the first anchor portion 202 and the second anchor portion 212 is not covered. As shown in FIG. Figure 2 As shown, the septum member 204 is coupled to the first anchor portion 202. The septum 206 at least partially covers the first anchor portion 202 to restrict blood flow laterally through the first anchor portion 202. Additionally, the second anchor portion 212 is substantially uncovered to allow blood flow laterally through the second anchor portion 212.

[0050] The implantable medical device 200 may be configured to increase resistance and reduce blood flow distal to it. The implantable medical device 200 may be adjustable in diameter. In some cases, the implantable medical device 200 may be adjustable in diameter by means of an expandable force applied within the implantable medical device 200. The expandable force may be applied by means of a capsule structure. As described above, the implantable medical device 200 may include a stent and a graft structure. Either or both of the stent and graft structures of the implantable medical device 200 may be configured to maintain a new diameter in response to an expandable force. The stent portion of the implantable medical device 200 may be made of nitinol (NiTi) or stainless steel and may be self-expandable or capsule-expandable.

[0051] Figure 3A-3B An exemplary implantable medical device 200 is shown implanted in a patient's blood vessel 300 according to various aspects of the present disclosure. In some cases, the implantable medical device 200 can be used in a method of altering blood flow 314 in a patient's blood vessel. Figure 3A-3B As shown, an implantable medical device 200 is implanted within a blood vessel 300. The implantable medical device 200, including a stent element and a graft component 204 attached to at least a portion of the stent element, can be delivered to a target location (e.g., the aorta) within the blood vessel 300. The implantable medical device 200 is configured to at least partially increase blood flow into one or more side branches 308, 310, 312 that branch off (leave / deviate from / extend from) 300 from the blood vessel (the aorta).

[0052] The implantable medical device 200 may include one or more anchoring portions, including a first anchoring portion 202 and a second anchoring portion 212. The first anchoring portion 202 and the second anchoring portion 212 may include a stent element. In addition, the implantable medical device 200 may include a flow restriction portion 206 having a reduced diameter section relative to the anchoring portions 202, 212. Figure 3A-3B As shown, the flow restriction portion 206 tapers inwardly from one or both of the anchor portions 202 , 212 .

[0053] In some cases and as Figure 2 As shown, the anchoring portions 202, 212 and the flow-restricting portion 206 form an hourglass shape. Figure 2 As shown, the implantable medical device 200 tapers inwardly from both the first anchoring portion 202 and the second anchoring portion 212. However, the septum member 204 is only coupled to one side of the inwardly tapered portion. The septum member 204 can be configured to increase flow resistance within the blood vessel and increase blood flow into one or more side branches that branch off (leave the blood vessel / deviate from the blood vessel / extend from the blood vessel) from the blood vessel. Therefore, the flow-restricting portion 206 is considered to be a portion of the implantable medical device 200 that has a reduced diameter relative to the anchoring portions 202, 212 to which the septum member 204 is attached or coupled. Therefore, Figure 3A -B shows an implantable medical device 200 in which the flow-restricting portion 206 is disposed adjacent to the first anchoring portion 202. In other cases, such as Figure 4 As shown, the flow restriction portion 206 may be disposed adjacent to the second anchor portion 212. Additionally, where the septum 204 is disposed on two portions of reduced diameter relative to the anchor portions 202, 212, the flow restriction portion 206 may be two portions of reduced diameter.

[0054] The septum member 204 can be configured to increase blood flow into one or more side branches that branch off (leave / deviate from / extend from) a blood vessel by about 10% to about 20%, about 20% to about 30%, about 30% to about 40%, or any amount therebetween. In addition, the septum member 204 is coupled to one of the first anchor portion 202 and the second anchor portion 212, and the other of the first anchor portion 202 and the second anchor portion 212 is not covered. Figure 3A-3B As shown, the diaphragm member 204 is coupled to the first anchoring portion 202. In addition, the diaphragm 206 can be coupled to the entirety of the first anchoring portion 202 (e.g., Figure 3A as shown) or a portion of the first anchoring portion 202 (as shown Figure 3B ). The second anchor portion 212 may be uncovered and configured to allow blood flow laterally past the second anchor portion 212.

[0055] The second anchoring portion 212 is configured to facilitate blood flow into one or more side branches 308, 310, 312 branching off (leaving / deviating from / extending from) the blood vessel 300 without blocking the one or more side branches 308, 310, 312 branching off (leaving / deviating from) the blood vessel. Figure 3A and 3B As shown, the flow-restricting portion 206 of the implantable medical device 200 is a closed section that substantially blocks blood flow 314 flowing laterally through the implantable medical device 200 , and the second anchoring portion 212 is an open section that substantially allows blood flow 314 flowing laterally through the implantable medical device 200 .

[0056] In some cases, the implantable medical device 200 can produce long-term or chronic physiological changes in the patient. The implantable medical device 200 that changes the flow into the kidney can produce a neurohormonal response that causes changes in the patient to move toward normal kidney function. The kidney is a feedback regulator of systemic pressure through the patient's body. The implantable medical device 200 for changing the flow into the kidney provides a non-pharmacological means of affecting the kidney's natural feedback mechanism to regulate systemic pressure.

[0057] By adjusting the degree of hemodynamic change in renal perfusion, patient-specific adjustments can be made to regulate blood pressure. Adjusting the aortic flow resistance imparted by the implantable medical device 200 can affect the renal artery pressure and / or flow rate (flow), which in turn can manifest as a transient or persistent change in systemic blood pressure. The changes in kidney-mediated blood pressure levels caused by the implantable medical device 200 can themselves have therapeutic benefits. Similarly, the changes in kidney-mediated blood pressure levels caused by the implantable medical device 200 can be used in combination with various blood pressure medications to optimize blood pressure management on an individualized basis.

[0058] In some cases, the implantable medical device 200 can increase or decrease resistance to blood flow 314 within the aorta distal to the branches 308, 310 (e.g., the renal arteries) by between about 5% and about 30% compared to normal blood flow. The implantable medical device 200 can occlude the aorta distal to the branches 308, 310 (e.g., the renal arteries) by between about 5% and about 30% to increase blood flow 314 into the kidney. The positioning of the implantable medical device 200 can be changed to achieve an increase of between about 5% and about 30% in blood flow 314 into the kidney. In addition, the amount of coverage and the location of coverage of the diaphragm member 204 can be changed to achieve the desired blood flow.

[0059] In some cases, the diaphragm member 204 is configured to induce between about 40% and about 80% stenosis of at least a portion of the patient's aorta distal to the branches 308, 310 (e.g., the renal arteries 118, 120), and to alter blood flow into one or more of the side branches 308, 310 of the blood vessel (aorta) 300 (e.g., one or both of the renal arteries 118, 120), while maintaining substantially unrestricted blood flow within the aorta proximal to one or more of the side branches 308, 310 of the blood vessel (aorta) 300, more specifically, in the abdominal aorta. In some cases, the induced stenosis is between 50% and 70%. Clinically, measurements of ankle joint pressure, Doppler ultrasound velocity, ankle-brachial index, or other hemodynamic parameters in the lower extremity can be used to optimize the magnitude of the induced stenosis while ensuring adequate limb perfusion. In addition, the diaphragm member 204 can be configured to increase the blood pressure at the ostium of the at least one renal artery relative to the venous outflow pressure and increase the pressure across the patient's kidney (relative to the venous outflow pressure), thereby causing more blood to flow through the kidney. The diaphragm member 204 can be configured to increase the blood pressure at the ostium of the at least one renal artery, which helps increase the fluid filtered by the kidney to increase diuresis and reduce fluid retention in the patient.

[0060] When implanted in the aorta, the device 200 is configured to redirect blood flow to at least one of the renal arteries by diverting the fluid in the aorta. In order to achieve increased renal perfusion, the resistance to blood flow distal to the renal artery can be increased, which reduces distal perfusion. Increased renal perfusion enhances renal production and thus removes fluid volume. In some cases, the device 200 is configured to produce a narrowed fluid lumen between about 40% and about 80% in a catheter in the patient's aorta at least partially distal to the renal artery, and changes the blood flow in at least one branch vessel (e.g., one or both of the renal arteries) of the aorta. In some cases, the restriction (flow restriction) caused is between about 50% and about 70% of the nominal flow.

[0061] When implanted in the vena cava, the device 200 can increase perfusion from a branch vessel (e.g., a renal vein) that terminates in the vena cava by changing the pressure within the vena cava to change the blood flow from the branch vessel of the vena cava. In some cases, the device 200 can be configured to create a narrowed flow lumen of between about 40% and about 90% in a catheter in the vena cava distal to at least one branch vessel. The use of a flow restriction device by reducing pressure in the renal vein, which will be discussed in further detail below, can increase renal perfusion hemodynamically rather than pharmacologically.

[0062] Additionally, the implantable medical device 200 may be implanted in another blood vessel of the patient leading to an organ. In these cases, the diaphragm component 204 is configured to cause a stenosis (narrowing) of between about 40% and about 80% of the blood vessel in which the implantable medical device 200 is implanted distally of the location where the implantable medical device 200 is implanted. Additionally, implanting the implantable medical device 200 in this manner alters the blood flow 314 into the organ to which the blood vessel leads (is introduced) while maintaining substantially unrestricted blood flow 314 in the blood vessel proximal to the implantation location.

[0063] In some cases, the implantable medical device 200 is disposed in a vessel other than the aorta or vena cava. In these cases, the flow altering element 208 can be configured to alter blood flow through the lumen to restrict blood flow in the vessel and induce a physiologically mediated therapeutic response in the patient. In some cases, the implantable medical device 200 is configured to induce a physiologically mediated therapeutic response to include increasing peripheral resistance within the vessel. The implantable medical device 200 can be configured to treat fistulas within the vessel, as well as to increase peripheral resistance within the vessel as described in further detail below.

[0064] Furthermore, if Figure 3A-3B As shown, the septum member 204 can be coupled to the first anchoring portion 202 at a location where the first anchoring portion 202 is configured to contact the vessel wall. In these cases, the location of the septum member 204 on the first anchoring portion 202 is configured to reduce thrombosis on the vessel wall. The septum member 204 can additionally allow continuous blood flow (retrograde or reverse) through the flow restriction portion 206 to reduce the possibility of blood stagnation, which may lead to clotting. More specifically, blood flows outside of the flow restriction portion 206 to reduce the possibility of clotting.

[0065] like Figure 3A-3B As shown, the flow restriction portion 206 is disposed adjacent to the side branch vessel 312 into which increased blood flow is desired. In some cases, the flow restriction portion 206 is disposed upstream of the side branch vessel 312 into which increased blood flow is desired. The second anchor portion 212 (opening section) can be disposed laterally adjacent to the side branch vessel 312 into which increased blood flow is desired to allow blood to flow laterally through the second anchor portion 212 without blocking the side branch vessel 312.

[0066] Figure 4Another exemplary implantable medical device 200 is shown implanted in a patient's blood vessel according to various aspects of the present disclosure. The implantable medical device 200, including a stent element and a graft component 204 attached to at least a portion of the stent element, can be delivered to a target location (e.g., the aorta) within a blood vessel 300. The implantable medical device 200 is configured to at least partially increase blood flow into one or more side branches 308, 310, 312 that branch off (leave / deviate from / extend from) 300 from a blood vessel (the aorta).

[0067] The implantable medical device 200 may include a first anchoring portion 202 and a second anchoring portion 212. The first anchoring portion 202 and the second anchoring portion 212 may include a stent element. In addition, the implantable medical device 200 may include a flow restriction portion 206 having a reduced diameter section relative to the anchoring portions 202, 212. Figure 4 As shown, the flow restriction portion 206 tapers inwardly from one of the anchor portions 202 , 212 .

[0068] However, the septum member 204 is only coupled to one side of the inwardly tapered portion. The septum member 204 can be configured to increase flow resistance within the blood vessel and increase blood flow (blood volume) into one or more side branches that branch off (leave / deviate from / extend from) the blood vessel. Thus, the flow-restricting portion 206 is considered to be a portion of the implantable medical device 200 that has a reduced diameter relative to the anchoring portions 202, 212 to which the septum member 204 is attached or coupled. Thus, Figure 4 The flow-restricting portion 206 of the implantable medical device 200 is shown disposed adjacent to the second anchoring portion 212 .

[0069] like Figure 4 As shown, the second anchoring portion 212 is a closed segment that substantially blocks blood flow 314 that flows laterally through the implantable medical device 200, and the first anchoring portion 202 is an open segment that substantially allows blood flow 314 that flows radially through the implantable medical device 200. Figure 3A -B and Figure 4 As shown in the implantable medical device 200 in FIG. 1 , the flow-restricting portion 206 can partially cover the side branch vessels 308, 310 into which increased blood flow is desired. In some cases, the flow-restricting portion 206 is at least partially disposed downstream of the side branch vessels 308, 310 into which increased blood flow is desired. The first anchoring portion 202 (opening section) can be disposed laterally adjacent to the side branch vessels 308, 310 into which increased blood flow is desired to be entered, so as to allow blood to flow laterally (laterally) through the first anchoring portion 202 without blocking the side branch vessels 308, 310.

[0070] In some cases, patients with heart failure (such as advanced heart failure) may have an elevated sympathetic nervous system state, in part because of reduced cardiac output (blood pressure and flow in one of the two kidneys). A compensatory output of this state is to generate a signal to try to maintain cardiac output, which puts further pressure on the heart (myocardial oxygen demand). The implantable medical devices and methods including implantable medical devices discussed herein involve increasing pressure in the kidneys (mean or peak systolic pressure) to reduce stimulation of neurohormonal responses (e.g., reduction in sympathetic activation of the nervous system). The result of reducing the activation of the sympathetic nervous system by means of an implantable medical device or a method including an implantable medical device can reduce resting heart rate and blood pressure.

[0071] In addition, in some cases, patients with heart failure (such as advanced heart failure) may activate the renin-angiotensin-aldosterone system (RAAS), in part because of reduced cardiac output leading to impaired blood flow to the kidneys. The result of elevated RAAS is the generation of signals that stimulate adverse myocardial structural changes. The implantable medical devices discussed herein and methods including implantable medical devices involve increasing the pressure (mean or peak systolic pressure) in the kidneys to reduce stimulation of RAAS. The result of reducing the activation of RAAS by means of an implantable medical device or a method including an implantable medical device can be reduced sympathetic nervous system activation and weakening of adverse cardiac remodeling.

[0072] Previous studies on implantable medical devices implanted in the aorta have been used to evaluate the response of canines to induced heart failure (coronary microembolism resulting in an ejection fraction of approximately 30%). Hemodynamic conditions were observed in the test group relative to the control group, indicating improved cardiac function and reduced sympathetic nervous system tone. For example, heart rate and mean arterial pressure decreased, while contractility increased relative to the control. These comparative results were supported by positive changes in biomarkers such as pro-BNP (B-type natriuretic peptide) and NGAL compared to the control. As an example, animals with implants produced about 35% more urine, creatinine levels increased by about 21%, and serum creatinine increased by about 52% due to diuretic stimulation. These results indicate that implantable medical devices placed in the aorta, such as implantable medical devices that direct blood to the kidneys or restrict blood flow in the aorta distal to the renal arteries, can help reduce fluid excess and cardiac stress symptoms associated with heart failure. The device is shown to increase blood pressure proximal to the stenosis, and in doing so, increase renal perfusion pressure, thereby increasing renal perfusion. The secondary effect of the device is to reduce activation of the RAAS system. The effectiveness of the device is based on the assessment of central hemodynamics, left ventricular (LV) function, and renal function.

[0073] Furthermore, previous studies have found that induced stenosis has little effect on flow or pressure until it reaches about 40%, after which the effect is dependent on arterial diameter and blood flow rate (blood flow). However, based on the above-mentioned animal studies, it has been found that there is a threshold above which the effect increases dramatically. Based on these results, the stenosis protocol is between about 40% to about 80%, and more specifically between about 50% to about 70%. Clinically, measurements of ankle joint pressures, Doppler ultrasound velocities, or other hemodynamic parameters in the lower extremities may be used to optimize the magnitude of the induced stenosis while ensuring adequate limb perfusion.

[0074] Furthermore, in some cases, the above devices describe a restriction of the diameter of the aorta or vena cava, however, the length of the restriction portion may also affect the amount of restriction in the aorta or vena cava. Thus, the length of the restriction portion and the diameter or circumference of the restriction portion may be varied to achieve a desired stenosis or restriction percentage.

[0075] Further, the devices discussed herein can be implanted intravascularly to treat arteriovenous (AV) fistulas. The formation of AV fistulas may result in a decrease in peripheral resistance within the vascular system. Implantation of the devices discussed herein at or adjacent to the AV fistula may increase flow resistance to nominal levels and offset the decrease in peripheral resistance caused by the AV fistula. In some cases, the device is implanted distal to the AV fistula, proximal to the AV fistula, or across the AV fistula.

[0076] Examples of synthetic polymers that can be used as graft components coupled to at least a portion of the stent element(s) include, but are not limited to, nylon, polyacrylamide, polycarbonate, polyoxymethylene, polymethyl methacrylate, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl chloride, polyurethane, elastomeric silicone polymers, polyethylene, polypropylene, polyurethane, polyglycolic acids, polyesters, polyamides, and mixtures, blends, and copolymers thereof are suitable for use as membrane materials. In one embodiment, the membrane material is made of (a class of) polyesters, polyfluorocarbons, and porous or non-porous polyurethanes, such as polyethylene terephthalate, including and and polyaramids, such as The above-mentioned polyfluorocarbons are such as hexafluoropropylene ( or ). In some cases, the diaphragm material includes expanded fluorocarbon polymers (particularly PTFE) materials described in British Patent Nos. 1355373, 1506432 or 1506432 or in U.S. Patent Nos. 3953566, 4187390 or 5276276, which are incorporated herein by reference in their entirety. Included in this class of preferred fluoropolymers are polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), copolymers of tetrafluoroethylene (TFE) and perfluoro(propyl vinyl ether) (PFA), homopolymers of polytrifluorochloroethylene (PCTFE), and copolymers thereof with TFE, ethylene-chlorotrifluoroethylene (ECTFE), copolymers of ethylene-tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF). ePTFE is particularly preferred due to its widespread use in vascular prostheses. In certain embodiments, the membrane material comprises a combination of the materials listed above.

[0077] Other examples of graft materials include, but are not limited to, vinylidene fluoride / hexafluoropropylene hexafluoropropylene (HFP), tetrafluoroethylene (TFE), vinylidene fluoride, 1-hydropentafluoropropylene, perfluoro(methyl vinyl ether), chlorotrifluoroethylene (CTFE), pentafluoropropylene, trifluoroethylene, hexafluoroacetone, hexafluoroisobutylene, fluorinated poly(ethylene-co-propylene) (FPEP), poly(hexafluoropropylene) (PHFP), poly(chlorotrifluoroethylene) (PCTFE), poly(vinylidene fluoride) (PVDF), poly(vinylidene fluoride-co-tetrafluoroethylene) (PVDF-TFE), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(tetrafluoroethylene-co-hexafluoropropylene) Poly(PTFE-HFP), poly(tetrafluoroethylene-co-vinyl alcohol) (PTFE-VAL), poly(tetrafluoroethylene-co-vinyl acetate) (PTFE-VAC), poly(tetrafluoroethylene-co-propylene) (PTFEP), poly(hexafluoropropylene-co-vinyl alcohol) (PHFP-VAL), poly(ethylene-co-tetrafluoroethylene) (PETFE), poly(ethylene-co-hexafluoropropylene) (PEHFP), poly(vinylidene fluoride-co-chlorotrifluoroethylene-ethylene) (PVDF-CTFE), and combinations thereof, and other polymers and copolymers described in U.S. Publication No. 2004 / 00663805, the entire contents of which are incorporated herein by reference for all purposes. Other polyfluoropolymers include tetrafluoroethylene (TFE) / perfluoroalkyl vinyl ether (PAVE). The PAVE may be perfluoromethyl vinyl ether (PMVE), perfluoroethyl vinyl ether (PEVE), or perfluoropropyl vinyl ether (PPVE), as substantially described in U.S. Publication No. 2006 / 0198866 and U.S. Pat. No. 7,049,380, both of which are incorporated herein by reference in their entirety for all purposes. Other polymers and copolymers include: polylactides, polycaprolactone-glycolides, polyorthoesters, polyanhydrides; polyamino acids; polysaccharides; polyphosphazenes; poly(ether-ester) copolymers such as PEO-PLLA or blends thereof, polydimethylsiloxanes; poly(ethylene-vinyl acetate); acrylate-based polymers or copolymers such as poly(hydroxyethyl methyl methacrylate), polyvinyl pyrrolidone; fluorinated polymers such as polytetrafluoroethylene; cellulose esters, and any polymer and copolymer described in U.S. Publication No. 2004 / 0063805, the entirety of which is incorporated herein by reference.

[0078] As discussed herein, a graft component can be attached to a self-expanding stent element using a coupling member having at least one substantially flat surface, typically a flat band or strap. In some cases, the strap member is made of expanded PTFE (ePTFE) coated with an adhesive. The adhesive can be a thermoplastic adhesive. In some cases, the thermoplastic adhesive can be fluorinated ethylene propylene (FEP). More specifically, the FEP-coated side of the ePTFE can face and contact the outer surface of the self-expanding stent and the graft component, thereby attaching the self-expanding stent to the graft component. Materials and methods for attaching a stent to a graft are discussed in U.S. Patent No. 6,042,602 to Martin, which is incorporated herein by reference for all purposes.

[0079] The stent elements discussed herein can be made of a variety of biocompatible materials. These materials can include 316L stainless steel, cobalt-chromium-nickel-molybdenum-iron alloy ("cobalt-chromium"), other cobalt alloys such as L605, tantalum, nickel-titanium alloys (e.g., nitinol), or other biocompatible metals. In some cases, as discussed in detail above, the stent (and graft) can be self-expanding. The prosthesis can be capsule expandable.

[0080] Various metals, various materials such as superelastic alloys of Nitinol are suitable for these stents. The main requirement for the materials is that they are reasonably elastic even when made into very thin sheets or small diameter wires. Various stainless steels that have been physically, chemically, and otherwise treated to produce high elasticity are suitable for these stents, as are superelastic alloys such as cobalt-chromium alloys (e.g., Other metal alloys such as ), platinum / tungsten alloys, and especially nickel-titanium alloys (eg, Nitinol) are also suitable.

[0081] Various modifications and additions may be made to the exemplary embodiments discussed without departing from the scope of the present disclosure. For example, although the embodiments discussed above specify particular features, the scope of the present invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Therefore, the scope of the present invention is intended to cover all such substitutions, modifications and variations that fall within the scope of the claims, as well as all equivalents thereof.

Claims

1. An implantable medical device for altering blood flow in a patient's blood vessel, the implantable medical device comprising: a first anchor portion and a second anchor portion, the first anchor portion and the second anchor portion being configured to contact a vessel wall of a blood vessel; a flow restriction portion having a first section having a reduced diameter relative to the first anchor portion and a second section having a reduced diameter relative to the second anchor portion; as well as A diaphragm component, the diaphragm component is connected to and covers one of the first anchor portion and the second anchor portion, and the other of the first anchor portion and the second anchor portion is not covered, the diaphragm component is also connected to one of the first segment of the flow-restricting portion and the second segment of the flow-restricting portion, so that the other of the first segment of the flow-restricting portion and the second segment of the flow-restricting portion is not covered, and the diaphragm component is configured to increase flow resistance within the main blood vessel and increase blood flow into one or more side branches branching from the blood vessel.

2. The device according to claim 1, characterized in that The septum member is configured to increase blood flow into the one or more side branches branching from the blood vessel by between 5% and 30%, and the side branches are proximal to the flow restriction.

3. The device according to any one of claims 1 to 2, characterized in that The flow restriction portion forms an hourglass shape, and the flow restriction portion tapers inwardly to reduce a diameter of one or more of the first anchor portion and the second anchor portion.

4. The device according to claim 1, characterized in that The membrane member is coupled to the first anchor portion to at least partially cover the first anchor portion to restrict blood flow laterally through the first anchor portion.

5. The device according to claim 4, characterized in that The second anchoring portion is uncovered and is configured to allow blood flow laterally through the second anchoring portion.

6. The device according to claim 5, characterized in that The second anchoring portion is configured to reduce the likelihood of occluding the one or more side branches branching from the blood vessel.

7. The device according to any one of claims 4 to 5, characterized in that The membranous member is coupled to the first anchor portion at a location where the first anchor portion is configured to contact the vessel wall.

8. The device according to claim 7, characterized in that The position of the membranous member on the first anchoring portion is configured to reduce thrombosis.

9. The device according to any one of claims 1 to 2, characterized in that The blood vessel is the patient's aorta, and the side branches are one or more of a renal artery, a celiac artery, a hepatic artery, and a mesenteric artery, and the implantable medical device is configured to be implanted in the aorta and increase blood flow into one or more of the renal artery, the celiac artery, the hepatic artery, and the mesenteric artery.

10. The device according to claim 9, characterized in that The diaphragm member is configured to increase blood pressure at the ostium of at least one renal artery relative to venous outflow pressure and to increase pressure across the patient's kidney, thereby causing more blood to flow through the kidney.

11. The device according to claim 10, characterized in that The diaphragm member is configured to increase blood pressure at the ostium of at least one renal artery, which helps increase fluid filtered by the kidney to increase diuresis and reduce fluid retention in the patient.

12. The device according to any one of claims 1 to 2, characterized in that The membranous member is configured to cause between 40% and 80% stenosis of the blood vessel distal to the one or more side branches.

13. The device according to claim 12, characterized in that The membranous member is configured to cause between 50% and 70% stenosis of the blood vessel distal to the one or more side branches.

14. The device according to any one of claims 1 to 2, characterized in that The one or more anchoring portions are configured to bear against a vessel wall in the vena cava and the septum component is configured to form a narrow flow lumen of between 40% and 90% of the vena cava distal to one or both of the renal veins to facilitate blood flow out of the kidney.

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