Improving renal function using cardiac assist device

Abstract

The invention relates to improving renal function using a cardiac assist device. Systems and methods for improving renal function. A first mechanical circulation support system (MCS) is introduced into the heart of the patient and a second mechanical circulation support system is introduced into the inferior vena cava or renal vein of the patient. The second mechanical cycle support system operates while the first mechanical cycle support system is operating. Kidney parameters are monitored during operation of the first mechanical circulation support system and the second mechanical circulation support system. The combined operation of the two mechanical circulation support systems results in a change in renal parameters (e.g., pressure drop in renal veins), indicating an improvement in renal function. Once it is determined that the kidney parameter is below the target threshold, operation of the second mechanical cycle support device is stopped.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 202080034319X (PCT / US2020 / 031861) with the title "Improving Renal Function Using a Cardiac Assist Device", the international filing date of which is May 7, 2020, and the date of entry into the national phase is November 8, 2021.

[0002] Cross - reference to related applications

[0003] This application claims the priority of U.S. Patent Application (Serial No.: 16 / 406,896) with the title "Use of Cardiac Assist Device to Improve Kidney Function" filed on May 8, 2019, the entire content of which is incorporated herein by reference. Background of the invention

[0004] The kidneys play a central role in controlling arterial hydraulic pressure in the body. They regulate renal excretion by changing water excretion (diuresis) and by changing salt excretion (natriuresis). This regulation is reflected in the renal excretion curve ( Figure 1 ), in which urine output varies according to arterial pressure. Under normal conditions, the kidneys can autoregulate themselves so as to increase or decrease urine excretion and renal blood flow according to increases or decreases in blood pressure or blood flow velocity or changes in salt concentration. However, impairment or other changes in renal function may impair autoregulation. For example, impaired renal function increases arterial pressure and also increases the content of water and salt in the circulation. Conversely, heart failure or coronary heart disease significantly reduces cardiac output, which in turn reduces blood flow to the renal arteries and impairs urine excretion.

[0005] Many people suffer from acute kidney disease, renal failure and other kidney diseases. Some kidney diseases are thought to be caused or exacerbated by contrast agents, dyes and other media used during CT scans, angiograms and other investigative procedures. These conditions include, for example, contrast - induced nephropathy and nephrogenic systemic fibrosis, or general nephrotoxicity. Patients with diabetes, heart, blood and other vascular diseases may have an increased susceptibility to such diseases. A common sign of kidney disease is a decrease in glomerular filtration rate (GFR) and renal excretion, and this acute condition is called oliguria (a sharp decrease in urine excretion).

[0006] Particularly when undergoing surgery, patients with impaired cardiac function and / or pre-existing kidney conditions may require coronary artery bypass grafting. Due to surgical stress, their hearts release stressors through their bodies. The type and amount of stressors released by the heart can vary depending on the length or nature of the surgery (such as CABG, valve replacement, valve repair, etc.). Monitoring the renal excretion of the patient during or immediately after surgery serves as an indicator of recovery. For example, an increase in creatinine or a decrease in filtration rate can be monitored to measure the patient's recovery. Current systems (such as ECMO) that provide flat-line pressure do not improve renal function and may instead damage the kidneys by placing them under high pressure. Monitoring renal excretion as an indicator of recovery is particularly important for high-risk cardiac patients who also often suffer from acute kidney disease, failure, or disorders (such as STEMI, CS, PCI).

[0007] There is a desire to provide improved methods and systems that can improve renal function, particularly in the context of vascular diseases. Specifically, there is a desire to provide a system or method that can provide one or more of improved renal excretion, reduced nephrotoxicity of various agents, and controlled renal autoregulation. There is a desire to provide a system or method that can increase the flow into the kidneys to increase urine excretion and the processing of unwanted stressors out of the body. There is also a desire to provide a system or method that can monitor renal parameters to determine whether the flow into the kidneys is sufficient such that an increase in the flow into the kidneys is no longer needed. Summary of the Invention

[0008] Methods and systems for solving one or more of the foregoing problems are provided herein. Renal excretion can be increased by increasing blood flow through the kidneys. Blood flow through the kidneys can be regulated by: reducing the cardiac load and maintaining or increasing the arterial pressure upstream of the kidneys; maintaining or reducing the venous pressure downstream of the kidneys, or a combination of both - selected to maintain or increase the pressure gradient across the kidneys. At least one advantage of reducing the cardiac load and increasing the arterial pressure upstream of the kidneys is to increase the release of one or more humoral factors that act on renal receptors (at or near the renal artery or glomerulus or any nephron component) or other receptors in vascular tissue. The increase in these humoral factors bound to the kidneys advantageously enhances the ability of the kidneys to process unwanted stressors out of the body. Similarly, at least one advantage of reducing the venous pressure downstream of the kidneys is to increase blood flow through the kidneys (including humoral factors), thereby increasing renal excretion. The methods and systems provided herein also address renal monitoring by monitoring renal parameters to determine whether the second blood pump can be turned off. For example, by monitoring the pressure gradient across the kidneys or the venous pressure drop in the renal vein, at least one advantage is the ability to determine once the patient has sufficiently recovered renal function, such that the second blood pump can be turned off. In one example, the first blood pump and the second blood pump can be referred to as One of the blood pumps of the pump, and the first blood pump can be applied to the left or right side (or both sides) of the heart, for example, by using the techniques identified in any Attachment A.

[0009] In some embodiments, a method for regulating a patient's renal function is provided. The steps in the method include inserting a first mechanical assist device (e.g., a first blood pump) into the patient's heart and operating the first blood pump to increase aortic pressure. For example, the blood pump can be introduced into the left or right heart of the patient. In a left ventricular application, the inlet of the pump is positioned in the left ventricle, and the outlet of the pump is in the aorta. Alternatively, the blood pump can be inserted into the left atrium such that the inlet of the pump is in the left atrium and the outlet of the pump is in the left ventricle. Alternatively, the blood pump can be inserted at any location that reduces the cardiac load and maintains or increases cardiac output. The method further includes inserting a second mechanical assist device (e.g., a second blood pump) into the patient's inferior vena cava and operating the second blood pump while the first blood pump is operating. For example, the second blood pump is placed near or within the inferior vena cava, or within the inlet of the inferior vena cava, or within the renal vein. The inlet of the second blood pump can be placed at the junction between the patient's renal vein and the inferior vena cava. In another example, the second blood pump is configured to partially occlude the inferior vena cava such that operation of the second blood pump creates a pressure drop upstream of the second blood pump inlet (between the pump and the kidney, including within the renal vein). In these embodiments, operation of the first blood pump and the second blood pump achieves a target pressure drop at a location in the patient's renal vein or inferior vena cava. Thus, the first blood pump and the second blood pump can be operated simultaneously - the first pump on the arterial side of the kidney increases the pressure upstream of the kidney, while the second pump located distal (downstream) of the kidney reduces the kidney load and thus the pressure in the renal vein. In other adaptations, one of the blood pumps operates continuously while the other blood pump is selectively opened and closed to achieve the target pressure drop. The first blood pump and the second blood pump can also operate at different speeds for different amounts of time. For example, the first blood pump can operate at a speed of approximately 40,000 rpm for up to 6 hours, while the second blood pump can operate at a speed of 30,000 rpm for approximately 3 hours. Alternatively, the first blood pump and the second blood pump can operate at similar speeds for the same period of time.

[0010] At least one advantage of using the first blood pump is to relieve the load on the left or right ventricle (or both) of the heart, or the left or right atrium (or both), thereby not only improving blood circulation through the renal artery, but also stimulating the release of one or more humoral factors that act on renal receptors (at or near the renal artery, glomerulus, or any nephron component) or other receptors in vascular tissue. This stimulation increases renal output, helps to manipulate and maintain renal autoregulation, and also helps to protect the kidneys from toxicity and damage. Deploying and operating the first blood pump can be used to relieve left ventricular load, thereby reducing left ventricular pressure (and left atrial pressure) and volume, or relieve right ventricular load and reduce right ventricular pressure (and right atrial pressure) and volume, or both.

[0011] At least one advantage of relieving ventricular load by pumping blood from the ventricle into the artery and away from the heart (aorta or pulmonary artery) is a general increase in arterial pressure, which increases the pulsation of the vasculature and increases blood flow into the renal artery and kidney, thereby increasing the glomerular filtration rate. Another advantage of operating the first pump (e.g., pump) in the patient's heart is to increase the diastolic blood pressure - the kidney receives a large amount of blood flow through the diastolic blood pressure - without keeping the kidney continuously under high pressure. For example, with Another advantage of the pump in reducing cardiac load is to upregulate the production of one or more humoral factors in cardiac tissue (or arterial tissue) and release this one or more factors into the circulation. Most humoral factors are produced in the left atrium of the heart - reducing cardiac load can decompress the left atrium and promote the production of humoral factors (e.g., the production of ANP). The humoral factor(s) flowing to the receptor(s) in the kidney and / or other organs will actuate the receptor(s) in the kidney or other organ(s) and stimulate an increase in the function of that organ. The humoral factor flowing to the kidney will actuate the kidney receptor and stimulate an increase in the urine excreted from the kidney. For example, the released humoral factor binds to the kidney receptor or other organ receptor. When the humoral factor reaches the renal artery (and the renal nephrons of the kidney), the humoral factor binds to one or more kidney receptors and thereby actuates the afferent and / or efferent arterioles directly facing the mesangial cells in the glomerulus, thereby increasing or decreasing renal blood flow. Increasing renal blood flow will increase or decrease or maintain the glomerular filtration rate even when the renal perfusion pressure changes. Additionally, or alternatively, the humoral factor can activate the renal tubular wall to excrete and / or absorb or reabsorb glucose, salt, or other electrolytes into the urine, so that water from the surrounding vasculature and tissues will also passively follow the changes in the electrolyte levels in the urine, thereby causing corresponding regulation (increase / decrease / maintenance of urine output and urine content) even when faced with changing renal perfusion pressure as well as changes in blood electrolytes, glucose, and trace elements. The receptors implicated by this effect in the kidney can include atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), NT-proBNP, catecholamine receptors, adenosine receptors, angiotensin receptors (AT1, AT2), prostaglandin receptors, alpha-ketoglutarate receptors, glutamate receptors, to name just a few. For example, the kidney receptors are located in the renal nephrons or renal tubules or medulla or cortex of the kidney.

[0012] In some embodiments, operating a first blood pump in the heart maintains or increases the arterial pressure in the renal artery. In other embodiments, operating a second blood pump in the inferior vena cava maintains or decreases the renal venous pressure. For example, in one embodiment, the first blood pump is operated to increase the arterial pressure, while the second blood pump is operated to decrease the renal venous pressure. In another example, the first blood pump is operated to maintain the arterial pressure, while the second blood pump is operated to decrease the renal venous pressure. In yet another example, the first blood pump is operated to increase the arterial pressure, while the second blood pump is operated to maintain the renal venous pressure.

[0013] In some embodiments, an increased target pressure drop at a location in a patient's renal vein or inferior vena cava increases blood flow through the kidneys and raises renal output. For example, the target pressure drop is between about 4 mmHg and about 8 mmHg. In another example, the target pressure drop is between about 5 mmHg and about 7 mmHg. In one example, the target pressure drop is about 6 mmHg. The target pressure drop and the time period required to achieve the target pressure drop can vary based on the baseline of a particular patient and the patient's condition. For example, for a particular patient, the maximum achievable pressure drop may be lower than the target pressure drop (e.g., 2 mmHg). In another example, for another patient, the target pressure drop can be achieved, but it may take longer to operate the first blood pump and the second blood pump to achieve it. The target pressure drop and the time period required to achieve the target pressure drop may also vary depending on the type of mechanical circulatory support device used - for example, the time required for a pump that provides an increased diastolic pressure will be shorter than that of an intra-aortic balloon pump or other types of mechanical circulatory systems.

[0014] In some embodiments, the target pressure drop corresponds to the blood pressure drop across the kidneys. In one example, the target pressure drop is between 85 mmHg and 95 mmHg. The target pressure drop and the time period required to achieve the target pressure drop can vary based on the baseline of a particular patient and the patient's condition. The target pressure drop and the time period required to achieve the target pressure drop may also vary depending on the type of mechanical circulatory support device used - for example, the time required for a pump that provides an increased diastolic pressure will be shorter than that of an intra-aortic balloon pump or other types of mechanical circulatory systems.

[0015] In some embodiments, the combined operation of the first blood pump and the second blood pump causes humoral factors to flow to renal receptors to stimulate an increase in urine excreted from the kidneys.

[0016] In some embodiments, the first blood pump (e.g., a pump) includes a pump motor and a pump housing distal to the pump motor. The pump housing surrounds a rotor, and a cannula extends distally from the pump housing. In some examples, a non-invasive extension extends distally from the cannula. For example, the non-invasive extension is braided.

[0017] In some embodiments, the second blood pump includes a pump motor and a pump housing distal to the pump motor. The pump housing surrounds a rotor, and a cannula extends distally from the pump housing. In some examples, a non-invasive extension extends distally from the cannula. For example, the non-invasive extension is braided.

[0018] In some embodiments, the second pump is positioned within the inferior vena cava such that the distal tip of the atraumatic extension extends into the inferior vena cava to a point adjacent to the renal vein outlet. For example, the distal tip of the atraumatic extension extends between 0 and 2 centimeters from the point where the renal vein joins the inferior vena cava. At least one advantage of the distal tip extending between 0 and 2 centimeters from the point where the renal vein joins the inferior vena cava is the ability to stabilize the inlet of the pump at a desired location adjacent to the renal vein.

[0019] In other embodiments, a system for improving renal function includes a first mechanical assist device configured to reduce the cardiac load of a patient and a second mechanical assist device configured to reduce the renal vein pressure. For example, the first mechanical assist device is configured to reduce the load on at least one ventricle, at least one atrium, or at least one atrium and at least one ventricle or two atria and two ventricles of the patient's heart. The first mechanical assist device and the second mechanical assist device are configured to achieve a target pressure drop in the renal vein when operating simultaneously. In one example, one or both of the mechanical assist devices is a blood pump. In another example, the second mechanical assist device is a balloon pump.

[0020] In some embodiments, the system for improving renal function further includes a controller (e.g., Automated Impella (Automated Impella )) that is configured to receive arterial pressure from the first mechanical assist device and venous pressure from the second mechanical assist device. The controller determines whether the pressure drop in the renal vein is close to the target pressure drop in the renal vein and controls an adjustment to the operation of at least one of the first mechanical assist device and the second mechanical assist device. In one example, the adjustment to the operation helps to achieve the target pressure drop in the renal vein. In another example, when the target pressure drop is achieved, the adjustment to the operation includes shutting down one or both of the mechanical assist devices. In one example, the system includes two controllers (e.g., two Automated Impella ), each controller associated with a mechanical assist device (e.g., pump) and receiving data from their respective mechanical assist devices.

[0021] In some embodiments, the target pressure drop is configured to increase urine production. For example, the controller is configured to operate one or more of the mechanical assist devices at a corresponding rate to increase blood flow from the heart and stimulate the production of at least one humoral factor that binds to renal receptors or receptors of another organ to stimulate and / or regulate urine volume and urine composition from the kidneys.

[0022] In some embodiments, the second mechanical assist device includes a pump motor and a pump housing distal to the pump motor. The pump housing surrounds a rotor, and a cannula extends distally from the pump housing. In an example, the second mechanical assist device further includes an anchoring device configured to anchor the second mechanical assist device to the inferior vena cava when the second mechanical assist device is operating. The anchoring device surrounds a portion of the cannula. The anchoring device can be selectively actuated. For example, the anchoring device is a balloon. The balloon can be inflated to partially occlude the inferior vena cava. Alternatively, the anchoring device includes deployable arms that engage the wall of the inferior vena cava. For example, the anchoring device is a nitinol self-expanding cage.

[0023] In some embodiments, the second mechanical assist device is positioned such that an inlet is located at a position where the renal vein connects to the inferior vena cava.

[0024] In some embodiments, each of the first mechanical assist device and the second mechanical assist device includes a pressure sensor to measure arterial pressure and venous pressure, respectively. In one example, the pressure sensor is integrated with each of the first mechanical assist device and the second mechanical assist device. For example, the first mechanical assist device and the second mechanical assist device are pumps that include a differential pressure sensor or an optical pressure sensor. In another example, separate pressure sensor lines or Swan-Ganz catheters are inserted with each of the first mechanical assist device and the second mechanical assist device. In yet another example, one of the mechanical assist devices includes an integrated sensor while the other does not - rather, it is used in conjunction with a separate pressure sensor line or Swan-Ganz catheter.

[0025] In some embodiments, when both the first mechanical assist device and the second mechanical assist device are operating simultaneously, the difference between the measured venous pressure and the measured arterial pressure increases. For example, the difference between the measured venous pressure and the measured arterial pressure increases by about 1%. In another example, the difference increases by about 5%.

[0026] In yet another embodiment, a method for improving a patient's renal function includes inserting a first blood pump into a patient's heart and operating the first blood pump. The method further includes inserting a second blood pump into the patient's inferior vena cava and operating the second blood pump while the first blood pump is operating. The method also includes monitoring renal parameters and ending the operation of the second blood pump when the renal parameters reach a target level. For example, the target level of the renal parameter is a function of the aortic pressure. For example, the renal parameter is the creatinine level or ANP concentration in the blood or the renal vein pressure. In one example, the target level of the renal vein pressure is less than 15 mmHg. In another example, the renal parameter is the pressure drop across the kidney.

[0027] In some embodiments, a renal parameter is determined by measuring an arterial pressure and measuring a venous pressure and calculating a pressure difference between the measured arterial pressure and the measured renal venous pressure. In some embodiments, the method for improving a patient's renal function further comprises determining that the calculated pressure difference has reached a threshold.

[0028] In some embodiments, a first blood pump communicates with a first controller, while a second blood pump communicates with a second controller. For example, the first controller and the second controller are automated Impella (AIC). In one embodiment, the first controller and the second controller communicate to determine a pressure difference between the measured arterial pressure and the measured renal venous pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other objects and advantages will become apparent from the following detailed description of specific embodiments when considered in conjunction with the accompanying drawings, in which like reference numerals always refer to like parts, and in which:

[0030] Figure 1 An illustrative renal output curve is shown, in which urine output varies according to arterial pressure;

[0031] Figure 2 An illustrative embodiment of the system disclosed herein is shown; and

[0032] Figure 3 An illustrative method disclosed herein is shown. DETAILED DESCRIPTION

[0033] To provide an overall understanding of the systems, methods, and devices described herein, certain illustrative embodiments will be described. Although the embodiments and features described herein are specifically described as being used with an intracardiac heart pump system, it should be understood that all of the components and other features outlined below can be combined with each other in any suitable manner and can be adapted and applied to other types of medical devices, such as electrophysiology research and catheter ablation devices, angioplasty and stent devices, angiography catheters, peripherally inserted central catheters, central venous catheters, midline catheters, peripheral catheters, inferior vena cava filters, abdominal aortic aneurysm treatment devices, thrombectomy devices, transcatheter aortic valve replacement (TAVR) delivery systems, cardiac treatment and cardiac assist devices (including balloon pumps), cardiac assist devices implanted using a surgical incision, and any other vein- or artery-based catheters and devices.

[0034] The systems, methods, and devices described herein achieve an improvement in renal function by maintaining or increasing the arterial pressure upstream of the kidney, maintaining or decreasing the venous pressure downstream of the kidney, or a combination of both, to increase blood flow through the kidney and thereby increase renal output.

[0035] Figure 1An illustrative renal excretion curve is shown, in which urine excretion varies according to arterial pressure. For example, as described above, a higher arterial pressure increases blood flow to the kidneys. Arterial blood transports humoral factors to the kidneys, such that a higher arterial pressure results in an increased amount of humoral factors reaching the kidneys and binding to receptors on the kidneys, thereby enhancing renal function and increasing urine excretion.

[0036] Figure 2 An illustrative embodiment of system 200 is shown, which is configured to provide a similar or higher arterial pressure, a similar or lower venous pressure, or a combination of both. A higher arterial pressure (input into an organ such as the kidneys) will result in an increased blood flow through the organ. For example, for the kidneys, a higher arterial pressure will result in an increased blood flow through the kidneys, and in turn, an increased renal urine excretion. Similarly, a lower venous pressure (at the organ outlet, such as at the kidney outlet) will result in an increased blood flow through the organ. For example, for the kidneys, a higher arterial pressure will result in an increased blood flow through the kidneys, and in turn, an increased renal urine excretion. A combination of a higher arterial pressure (input into an organ such as the kidneys) and a lower venous pressure (at the organ outlet, such as at the kidney outlet) will result in a similar or greater increase in blood flow through the organ. When the organ is the kidneys, a combination of a higher arterial pressure and a lower venous pressure will result in an increased renal urine excretion. System 200 includes pump 202 and pump 222. For example, pumps 202 and 222 are pumps. Alternatively, pumps 202 and 222 are other mechanical circulatory assist devices, such as expandable pumps, intra-aortic balloon pumps, or extracorporeal membrane oxygenation systems (ECMO).

[0037] Pumps 202 and pump 222 control the input and output into an organ (e.g., Figure 2 the kidneys 250 therein). For example, the kidneys 250 can be the left kidney or the right kidney. In one example, the combination of pumps 202 and 222 controls the input and output into both kidneys. For example, operating one or both blood pumps changes the flow rate and velocity of the blood through the organ (e.g., the kidneys). For example, operating one or both blood pumps increases the flow rate and velocity of the blood through the kidneys.

[0038] As Figure 2 shown, pump 202 is a first blood pump having an intubation 210, a distal extension 212, a catheter 214, a motor 204 and a rotor 206 in a housing 208. As Figure 2As shown in the example, the pump 202 is positioned such that the distal extension 212 is in the left ventricle while the rotor 206 and the rotor housing 208 are in the aorta. When operating, the pump 202 draws blood through the inlet 216, through the cannula 210, and discharges it through the housing 208 (also referred to as the rotor shroud), thereby reducing the heart load. The distal extension 212 is used to stabilize the pump 202 in the ventricle. For example, the distal extension 212 is braided or J-shaped. When operating, the pump 202 reduces the left ventricular load and increases the pressure in the aorta, thereby increasing the arterial pressure downstream. The pump 202 is capable of operating at a range of speeds, resulting in a range of flow rates and associated increases in aortic pressure. For example, the pump 202 operates at a flow rate between approximately 1.5 L / min and 6 L / min. In one example, the pump 202 operates at a flow rate of approximately 5 L / min. The pump 202 can be percutaneously inserted into the patient via the femoral artery or via the subclavian vein.

[0039] As shown in Figure 2, the pump 222 is a second blood pump having a cannula 220, a distal extension 242, a catheter 224, a motor 223 and a rotor 226 in a housing 228. As Figure 2 shown in the example, the pump 222 is positioned in the inferior vena cava. When operating, the pump 222 draws blood through the inlet 236, through the cannula 220, and discharges it through the rotor housing 228 (also referred to as the rotor shroud). The rotor housing 228 having the rotor 226 is in the inferior vena cava, downstream of the inlet 236 which is also in the inferior vena cava. In one example, for example as Figure 2As shown, the pump 222 includes a distal extension 242 that stabilizes the pump 222 in the inferior vena cava or at the junction between the inferior vena cava and the renal vein. For example, the distal extension 242 is braided or J-shaped. The pump 222 also includes an anchoring mechanism 240 that is positioned on the cannula between the inlet 236 and the rotor housing 228 through which blood exits the pump. The anchoring mechanism 240 can both anchor the pump 222 at a desired location along the inferior vena cava and partially occlude the inferior vena cava to allow the pump 222 to operate over the entire anchoring mechanism. For example, the anchoring mechanism 240 anchors the pump 222 between about 1 - 5 centimeters downstream of the renal vein. In another example, the anchoring mechanism 240 anchors the pump 222 between about 2 - 3 centimeters downstream of the renal vein. In one example, the anchoring mechanism 240 is a balloon that can be selectively inflated to at least partially occlude the inferior vena cava. For example, the size, shape, material, and location of the balloon on the cannula 220 are selected to achieve different degrees of occlusion in the inferior vena cava. In another example, the anchoring mechanism 240 is an expandable fusion device. For example, the anchoring mechanism 240 is a self-expanding fusion device (e.g., nitinol) that is surrounded by a sheath for insertion and self-expands once the sheath is removed in situ. The fusion device abuts against the wall of the inferior vena cava and holds the pump 222 in place. In one example, the fusion device can taper proximally and distally along the cannula and is covered with a biocompatible covering material to partially occlude the inferior vena cava.

[0040] The partial occlusion of the inferior vena cava in combination with the operation of the pump 222 draws blood from a location within the inferior vena cava and / or renal vein to a location downstream of the pump inlet 236, resulting in a pressure drop. This pressure drop can be measured as the pressure drop in the inferior vena cava upstream of the pump 222 (e.g., near the renal vein), or the pressure drop in the renal vein. Alternatively, this pressure drop can be measured as the drop between the arterial pressure entering the kidney across the kidney and the venous pressure exiting the kidney (e.g., in the renal vein).

[0041] The pump 222 can be percutaneously inserted into the patient via the femoral artery or via the subclavian vein. In one example, the pump 222 and the pump 202 are inserted through different percutaneous access points. Alternatively, the pump 222 and the pump 202 are inserted through the same percutaneous access point (e.g., the subclavian vein).

[0042] In one example, each pump (e.g., pumps 202, 222) includes a pressure sensor. For example, both pumps include an integrated pressure sensor, such as a differential pressure sensor, a piezoelectric pressure sensor, or an optical pressure sensor. In another example, both pumps include a separate pressure sensor that is introduced on a pressure sensor line or a Swan-Ganz catheter. Alternatively, one pump includes an integrated pressure sensor while the other pump uses a separate pressure sensor. Pump 202 may include an integrated pressure sensor for detecting pressure. For example, pump 202 may include a differential pressure sensor, one side of which is exposed to the blood pressure outside the inlet region while the other side of the sensor is exposed to the blood pressure inside the cannula 210. In this example, the sensor generates an electrical signal proportional to the difference between the two pressures, and the electrical signal is generated for display on a controller (e.g., an automatic controller). Alternatively, pump 202 may be introduced into a patient together with a Swan-Ganz catheter for measuring pressure. Similarly, pump 222 may include an integrated pressure sensor for detecting pressure. For example, pump 222 may include a differential pressure sensor, one side of which is exposed to the blood pressure outside the inlet region while the other side of the sensor is exposed to the blood pressure inside the cannula 210. In this example, the sensor generates an electrical signal proportional to the difference between the two pressures, and the electrical signal is generated for display on a controller (e.g., an automatic controller). Alternatively, pump 222 may be introduced into a patient together with a Swan-Ganz catheter for measuring pressure.

[0043] Each pump (e.g., pumps 202 and 222) may be connected to a controller such as an automatic Impella that receives data from the pump and sensors associated with the pump (e.g., integrated sensors or separate sensors) and generates information regarding cardiac output and / or renal output for display to a user (e.g., a medical professional). As described in the examples below regarding Figure 3 the information from the controller is used to determine whether and when to stop the operation of one or more pumps.

[0044] As described below regarding Figure 3As described, by operating pump 222 while pump 202 is operating, both the input arterial pressure to kidney 250 and the output venous pressure from kidney 250 can be adjusted. At least one advantage of this dual-pump operation is the ability to not only increase the cardiac output and arterial pressure input to kidney 250, but also and / or decrease the venous pressure exiting kidney 250. Thus, operating pump 202 while pump 222 is operating increases the blood flow to the kidney and increases the amount of humoral factors reaching the kidney. Operating pump 202 while pump 222 is operating increases the blood flow out of the kidney. At least one advantage of this dual-pump operation is the ability to increase urine output and clear any stress factors, including, for example, stress factors caused by surgery.

[0045] Figure 3 An illustrative method 300 for improving renal function is shown. At step 302, a first blood pump (e.g., Figure 2 pump 202) is inserted into the patient's heart. At step 304, the first blood pump is operated to increase the aortic pressure. At step 306, a second blood pump (e.g., Figure 2 pump 222) is inserted into the patient's inferior vena cava. After inserting the second blood pump, an anchoring mechanism (e.g., Figure 2 anchoring mechanism 240) is deployed. For example, the anchoring mechanism is a balloon that surrounds a portion of the pump cannula (e.g., Figure 2 cannula 220 of pump 222 in ). In this example, the balloon surrounding this portion of the pump is inflated such that it anchors the pump in the inferior vena cava and partially occludes the inferior vena cava. At step 308, the second blood pump is operated while the first blood pump is operating. At step 312, the system determines whether a target renal parameter (e.g., a decrease in blood pressure in the renal vein) has been achieved at a location in either the patient's renal vein or inferior vena cava. If it is determined at step 312 that the target renal parameter (e.g., a decrease in blood pressure in the renal vein) has been achieved, operation of the second blood pump can be terminated (step 314). If it is determined at step 312 that the target renal parameter (e.g., a decrease in blood pressure in the renal vein) has not been achieved, a second determination is made as to whether to adjust the operation of the first blood pump and / or adjust the operation of the second blood pump (step 310). For example, the speed of the first blood pump (e.g., Figure 2 pump 202) can be modified (e.g., increased or decreased) independently of the speed of the second blood pump. In one example, the speed of the first blood pump is increased by approximately 1 L / min. Alternatively, the speed of the first blood pump is increased by approximately 2 L / min. Similarly, the second blood pump (e.g., Figure 2The speed of the pump 222) can be modified (e.g., increased or decreased) independently of the speed of the first blood pump. In another example, the speeds of both the first blood pump and the second blood pump can be increased. If it is determined in step 310 that no adjustment is needed, the method returns to determining whether the target renal parameter has been achieved (step 312). For example, the target renal parameter can be a target pressure drop in the renal vein, or a target pressure drop across the kidney. For example, the first blood pump and the second blood pump may have to operate for a longer period of time to have an effect on the arterial pressure, venous pressure, or both. Conversely, if it is determined in step 310 that an adjustment to the operation of either or both of the first blood pump and the second blood pump is needed, the method returns to step 308, where both the first blood pump and the second blood pump operate simultaneously.

[0046] For example, the pump controller (e.g., Figure 2 the controller of the pump 222 and / or the pump 202) is configured to operate one or both of the auxiliary devices (e.g., Figure 2 the pump 222 and / or the pump 202) at their respective rates to increase blood flow from the heart and stimulate the production of at least one humoral factor that binds to a renal receptor or another organ receptor to stimulate and / or regulate urine volume and urine composition from the kidney. In one example, as discussed above with respect to Figure 2 both pumps (pump 222 and pump 202) are connected to a single controller. The (one or more) controllers can receive data regarding renal parameters. For example, the renal parameter is the pressure drop at the kidney outlet. Alternatively, the renal parameter is the pressure drop across the organ. As another example, the renal parameter is the creatinine level or ANP concentration in the blood. In one example, the controllers of the two pumps communicate with each other.

[0047] In one example, the controller(s) may also compare the kidney parameter with a threshold value of the kidney parameter. For example, the controller(s) may continuously compare the kidney parameter with the threshold value in near real-time. Alternatively, the controller(s) may compare periodically. The threshold value may be user input. Alternatively, the controller may retrieve the threshold value from a database. For example, the database is a remote database that uses known clinical data regarding target kidney parameter values. In one example, the controller(s) is configured to generate an indicator that the threshold value of the kidney parameter has been reached for display. For example, the controller(s) may generate an alert. In another example, the controller(s) sends a message to a doctor. In one example, the doctor may turn off one or more of the pumps based on the kidney parameter monitoring. For example, once the kidney parameter (e.g., the pressure in the renal vein) has reached the threshold value, the doctor may turn off pump 222 while maintaining the operation of pump 202. In another example, the controller(s) detects that the kidney parameter has reached the threshold value and automatically turns off one or more of the pumps. At least one advantage of being able to determine when to turn off one or more of the pumps is the ability to safely wean the patient off support and the ability to improve the organ (e.g., kidney function) by subjecting the organ (e.g., the kidney) to hypertension for a longer period than necessary without damaging the organ.

[0048] The foregoing are merely illustrative of the principles of the present disclosure, and the systems, methods, and devices may be practiced by other embodiments other than the described embodiments, and the described embodiments are presented for purposes of illustration and not limitation. It should be understood that the systems, methods, and devices disclosed herein, although shown in a system for an intracorporeal heart pump, may be applied to other systems, methods, and devices for implantable heart pumps or implantable heart assist devices.

[0049] After reading the present disclosure, those skilled in the art will envision variations and modifications. The various features (including any components thereof) described or illustrated above may be combined or integrated in other systems. Additionally, some features may be omitted or not implemented. The various embodiments described or illustrated above may be combined in any manner.

[0050] Examples of changes, substitutions, and alterations may be determined by those skilled in the art and may be made without departing from the scope of the information disclosed herein. All references cited herein are hereby incorporated by reference in their entirety and become a part of this application.

Claims

1. A method for adjusting a patient's renal function, the method comprising the steps of: Inserting a first blood pump into the patient's heart; Operating the first blood pump to increase the aortic pressure; Inserting a second blood pump into the patient's inferior vena cava; And Operating the second blood pump and the first blood pump, wherein the operation of the first blood pump and the second blood pump achieves a target pressure drop at a location in the renal vein or the inferior vena cava of the patient.

2. The method according to claim 1, wherein operating the second blood pump comprises pumping the second blood pump while the first blood pump is pumping.

3. The method according to claim 2, wherein operating the first blood pump maintains or increases the arterial pressure in the renal artery.

4. The method according to claim 3, wherein operating the second blood pump maintains or decreases the renal vein pressure.

5. The method according to claim 4, comprising operating the first blood pump to increase the arterial pressure and operating the second blood pump to decrease the renal vein pressure.

6. The method according to claim 2, wherein the location is the vascular junction where the renal vein and the inferior vena cava of the patient are connected.

7. The method according to claim 2, wherein the target pressure drop increases blood flow through the kidneys and increases renal excretion.

8. The method according to claim 7, wherein the target pressure drop is between about 4 mmHg and about 8 mmHg.

9. The method according to claim 7, wherein the target pressure drop is between about 5 mmHg and about 7 mmHg.

10. The method according to claim 2, wherein the target pressure drop corresponds to the blood pressure drop across the kidneys.

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