Use of cardiac support devices to improve kidney function

Abstract

To provide systems and methods for improving a kidney function.SOLUTION: A first mechanical circulatory support system (MCS) is introduced in a patient's heart, and a second mechanical circulatory support system is introduced in a patient's inferior vena cava or renal vein. The second mechanical circulatory support system is operated while the first mechanical circulatory support system is operating. A renal parameter is monitored during operation of the first and second mechanical circulatory support systems. The combined operation of the first and second mechanical circulatory support systems results in a change in a renal parameter, e.g., a pressure drop in the renal vein, indicating an improvement in a kidney function. Once it is determined that the renal parameter is below a target threshold, the operation of the second mechanical circulatory support device is stopped.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Cross-reference of related applications This application claims priority to U.S. Patent Application No. 16 / 406,896, filed May 8, 2019, "Use of Cardiac Assist Device to Improve Kidney Function," the entire contents of which are incorporated herein by reference.

Background Art

[0002] background The kidneys play a central role in controlling arterial fluid pressure in the body. The kidneys regulate renal excretion by changing the amount of water excreted (diuresis) and also by changing the amount of salt excreted (natriuresis). That regulation is reflected in the renal excretion curve (FIG. 1), in which urine output varies in response to arterial pressure. In a normal state, the kidneys themselves can autoregulate by increasing or decreasing urine output and renal blood flow in response to increases or decreases in blood pressure or flow rate or changes in salt concentration. However, autoregulation can be impaired by injury or other changes in kidney function. For example, if kidney function is impaired, the levels of water and salt in the circulation may increase, which can lead to an increase in arterial pressure. Conversely, heart failure or coronary disease can dramatically reduce cardiac output, which reduces blood flow to the renal arteries and impairs urine excretion.

[0003] Many people suffer from acute kidney disease, renal failure, and other kidney disorders. Some kidney disorders are thought to be caused or exacerbated by contrast agents, dyes, and other media used during CT scans, angiography, and other diagnostic procedures. These conditions include, for example, contrast-induced nephropathy and nephrogenic systemic fibrosis, or general nephrotoxicity. Patients with diabetes, heart disease, hematological disorders, and other vascular diseases may be more susceptible to such disorders. One frequently observed indicator of kidney disorder is a decrease in glomerular filtration rate (GFR) and renal output, accompanied by an acute condition known as oliguria (acute decreased urine output).

[0004] Patients with weakened cardiac function and / or pre-existing renal conditions, especially during surgery, may require cardiac bypass. The hearts of these patients release stressors throughout the body as a result of the surgical stress. The type and amount of stressors released from the heart vary depending on the length and nature of the surgery (e.g., CABG, valve replacement, valve repair). Patients may have their renal output monitored as an indicator of recovery, either during or immediately after surgery. For example, elevated creatinine or decreased filtration rate may be monitored to gauge a patient's recovery. Current systems such as ECMO, which provide flat line pressure, do not improve renal function and may even damage the kidneys by placing them under high pressure. High-risk cardiac patients (e.g., STEMI, CS, PCI) are also prone to acute renal disease, renal failure, or renal impairment, making monitoring renal output as an indicator of recovery particularly important for these patients.

[0005] It is desirable to provide improved methods and systems that can improve renal function, particularly in cases of vascular disease. In particular, it is desirable to provide systems or methods that can provide one or more of the following: improved renal output, reduced nephrotoxicity of various active substances, and controlled renal autoregulation. It is desirable to provide systems or methods that can increase the flow into the kidneys to increase urine output and increase the process of eliminating undesirable stressors from the body. It is also desirable to provide systems or methods that can monitor renal parameters to determine whether the flow into the kidneys is sufficient to no longer require an increase in the flow into the kidneys. [Overview of the project]

[0006] overview Methods and systems for addressing one or more of the aforementioned problems are provided herein. Renal output can be increased by increasing blood flow through the kidney. Blood flow through the kidney can be regulated by reducing the load on the heart and maintaining or increasing arterial pressure upstream of the kidney; maintaining or decreasing venous pressure downstream of the kidney; or a combination of both—the choice is made to maintain or increase the pressure gradient across the kidney. At least one benefit of reducing the load on the heart and increasing arterial pressure upstream of the kidney is increased release of one or more humoral factors acting on renal receptors (located in or near the renal arteries, or on or near either the glomeruli or nephron components) or on other receptors in vascular tissue. Increased binding of these humoral factors to the kidney favorably increases the kidney's ability to process and remove unwanted stressors from the body. Similarly, at least one benefit of decreasing venous pressure downstream of the kidney is increased blood flow through the kidney (including humoral factors), thereby increasing renal output. 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, at least one advantage of monitoring the pressure gradient across the kidney or the venous pressure drop in the renal vein is that it is possible to decide to turn off the second blood pump once the patient has fully recovered renal function. In one embodiment, the first and second blood pumps may be any of the blood pumps known as Impella® pumps, and the first blood pump may be applied to the left or right side (or both) of the heart, for example, by using any of the techniques identified in Appendix A.

[0007] In some embodiments, a method is provided for regulating renal function in a patient. The steps in the method include inserting a first mechanical aid device, such as a first blood pump, into the patient's heart, and operating the first blood pump to increase aortic pressure. For example, the blood pump may be introduced into the patient's left or right heart. In application to the left ventricle, the pump's inlet is positioned within the left ventricle and the pump's outlet is in the aorta. Alternatively, the blood pump may be inserted into the left atrium such that the pump's inlet is in the left atrium and the pump's outlet is in the left ventricle. Alternatively, the blood pump may be inserted in any position that reduces the load on the heart and maintains or increases cardiac output. The method also includes inserting a second mechanical aid device, such as 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 may be placed near or within the inferior vena cava, within the entrance to the inferior vena cava, or within the renal vein. The inlet of the second blood pump may be located within the junction between the patient's renal vein and inferior vena cava. In another embodiment, the second blood pump is configured to partially occlude the inferior vena cava so that its operation creates a pressure drop upstream of its inlet (between the pump and the kidney, including within the renal vein). In these embodiments, the operation of the first and second blood pumps achieves the target pressure drop at a location within the patient's renal vein or inferior vena cava. Thus, the first and second blood pumps may be operated simultaneously—the first pump, located 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 load on the kidney and thereby decreases the pressure within the renal vein. In other adaptations, one of the blood pumps is operated continuously, and the other is selectively turned on and off to achieve the target pressure drop. The first and second blood pumps may also be operated at different speeds for different durations. For example, the first blood pump may operate at approximately 40,000 rpm for up to 6 hours, and the second blood pump may operate at 30,000 rpm for approximately 3 hours.Alternatively, both the first and second blood pumps may operate at similar speeds for the same duration.

[0008] At least one advantage of using a primary blood pump is that it reduces the load on the left ventricle or right ventricle (or both) or the left atrium or right atrium (or both) of the heart, thereby improving blood circulation through the renal arteries, as well as stimulating the release of one or more humoral factors acting on renal receptors (located in or near the renal arteries, or on or near any of the glomeruli or nephron components) or on other receptors in vascular tissue. Such stimulation increases renal output, helping to manipulate and maintain renal autoregulation, and also helps protect the kidneys from toxicity and damage. The placement and operation of a primary blood pump may be used to reduce the load on the left ventricle, thereby reducing left ventricular pressure (and left atrial pressure) and left ventricular volume, or to reduce the load on the right ventricle, thereby reducing right ventricular pressure (and right atrial pressure) and right atrial volume, or both.

[0009] At least one benefit of reducing the load on the ventricles by pumping blood from the ventricles into the arteries, thereby removing blood from the heart (either the aorta or pulmonary artery), is the overall increase in arterial pressure, which increases pulsatileness within the vascular structure and increases blood flow into the renal arteries and kidneys, thereby increasing the glomerular filtration rate. Another benefit of operating a primary pump in a patient's heart, such as an Impella® pump, is to increase diastolic blood pressure without constantly maintaining the kidneys under high pressure—the kidneys receive a considerable amount of blood flow due to diastolic blood pressure. Yet another benefit of reducing the load on the heart, such as with an Impella® pump, is to upregulate the production of one or more humoral factors in cardiac tissue (or arterial tissue) and their release into circulation. The vast majority of humoral factors are produced in the left atrium of the heart—reducing the load on the heart depressurizes the left atrium and boosts the production of humoral factors (e.g., ANP production). Humoral factors that reach receptors in the kidneys and / or other organs activate those receptors, stimulating increased function in those organs. Humoral factors that reach the kidneys activate renal receptors, stimulating increased urine output from the kidneys. For example, released humoral factors bind to renal receptors or receptors in other organs. When humoral factors reach the renal arteries (and nephrons of the kidneys), they bind to one or more renal receptors, thereby activating afferent and / or efferent arterioles directly facing the mesangial cells within the glomeruli, thereby increasing or decreasing renal blood flow. Increased renal blood flow increases, decreases, or maintains glomerular filtration rate, even if renal perfusion pressure changes. In addition, or alternatively, humoral factors may activate the tubular walls to excrete and / or absorb or reabsorb glucose, salt, or other electrolytes into the urine, in which case water from surrounding blood vessels and tissues passively follows the changes in urinary electrolyte levels, which in turn triggers corresponding regulation (increase / decrease / maintenance of urinary excretion and urinary contents), even when faced with changes in renal perfusion pressure as well as changes in blood electrolytes, glucose, and trace elements.Some examples of renal receptors affected by this effect include atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), NT-proBNP, catecholamine receptors, adenosine receptors, angiotensin receptors (AT1, AT2), prostaglandin receptors, alpha-ketoglutarate receptors, and glutamate receptors. Renal receptors, for example, are located in the nephrons, tubules, medulla, or cortex of the kidney.

[0010] In some embodiments, activating a first blood pump in the heart maintains or increases arterial pressure in the renal arteries. In other embodiments, activating a second blood pump in the inferior vena cava maintains or decreases renal venous pressure. For example, in one embodiment, the first blood pump is activated to increase arterial pressure, while the second blood pump is activated to decrease renal venous pressure. In another embodiment, the first blood pump is activated to maintain arterial pressure, while the second blood pump is activated to decrease renal venous pressure. In yet another embodiment, the first blood pump is activated to increase arterial pressure, while the second blood pump is activated to maintain renal venous pressure.

[0011] In some embodiments, the target pressure drop at a location within the patient's renal vein or inferior vena cava increases blood flow through the kidney and increases renal output. For example, the target pressure drop is approximately 4 mmHg to 8 mmHg. In another embodiment, the target pressure drop is approximately 5 mmHg to 7 mmHg. In one embodiment, the target pressure drop is approximately 6 mmHg. The target pressure drop and the time required to achieve it may vary considerably depending on the baseline and condition of a particular patient. 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 embodiment, for a different patient, the target pressure drop may be achievable, but it may require longer operating times for the first and second blood pumps. The target pressure drop and the time required to achieve it may also vary considerably depending on the type of mechanical circulatory support device used—for example, an Impella® pump that provides an increase in diastolic blood pressure is thought to require less time than an intra-aortic balloon pump or other types of mechanical circulatory systems.

[0012] In some embodiments, the target pressure drop corresponds to a blood pressure drop across the kidney. In one embodiment, the target pressure drop is 85 mmHg to 95 mmHg. The target pressure drop and the time required to achieve it may vary considerably depending on the baseline and patient condition of a particular patient. The target pressure drop and the time required to achieve it may also vary considerably depending on the type of mechanical circulatory support device used—for example, an Impella® pump that provides an increase in diastolic blood pressure may require less time than an intra-aortic balloon pump or other types of mechanical circulatory systems.

[0013] In some embodiments, the combined operation of the first and second blood pumps delivers humoral factors to renal receptors to stimulate increased urine output from the kidneys.

[0014] In some embodiments, the first blood pump (e.g., an Impella® pump) comprises a pump motor and a pump housing distal to the pump motor. The pump housing surrounds a rotor, and a cannula extends distal to the pump housing. In some embodiments, a non-traumatic extension extends distally from the cannula. For example, the non-traumatic extension is pigtail-shaped.

[0015] In some embodiments, the second blood pump comprises a pump motor and a pump housing distal to the pump motor. The pump housing surrounds a rotor, and a cannula extends distal to the pump housing. In some embodiments, a non-traumatic extension extends distally from the cannula. For example, the non-traumatic extension is pigtail-shaped.

[0016] In some embodiments, the second pump is positioned inside the inferior vena cava such that the distal end of the non-traumatic extension extends to a point inside the inferior vena cava adjacent to the outlet of the renal vein. For example, the distal end of the non-traumatic extension extends between 0 and 2 centimeters of the point where the renal vein connects to the inferior vena cava. At least one benefit of the distal end extending between 0 and 2 centimeters of the point where the renal vein connects to the inferior vena cava is that the inlet of the pump can be stabilized in a desired position adjacent to the renal vein.

[0017] In another embodiment, a system for improving renal function comprises a first mechanical assist device configured to reduce the load on the patient's heart and a second mechanical assist device configured to reduce renal venous 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 ventricle, or both atria and ventricles of the patient. The first and second mechanical assist devices are configured to achieve a target pressure reduction in the renal vein when operated simultaneously. In one embodiment, one or both of the mechanical assist devices are blood pumps. In another embodiment, the second mechanical assist device is a balloon pump.

[0018] In some embodiments, the system for improving renal function also includes a controller (e.g., Automated Impella Controller®) configured to receive arterial pressure from a first mechanical assist device and venous pressure from a second mechanical assist device. The controller determines whether the pressure drop in the renal vein is close to a target pressure drop in the renal vein and controls the adjustment of the operation of at least one of the first and second mechanical assist devices. In one embodiment, the adjustment of operation helps to achieve the target pressure drop in the renal vein. In another embodiment, when the target pressure drop is achieved, the adjustment of operation includes a step of turning off one or both of the mechanical assist devices. In one embodiment, the system includes two controllers (e.g., two Automated Impella Controller®); each controller is associated with one mechanical assist device (e.g., an Impella® pump) and receives data from its respective mechanical assist device.

[0019] In some embodiments, the target pressure drop is configured to increase urine production. For example, the controller is configured to activate one or more mechanical assistive devices at rates that increase blood flow from the heart and stimulate the production of at least one humoral factor that binds to renal receptors or receptors in another organ, in order to stimulate and / or regulate urine production and urinary fluid composition from the kidneys.

[0020] In some embodiments, the second mechanical assist device comprises a pump motor and a pump housing distal to the pump motor. The pump housing encloses a rotor, and a cannula extends distal to the pump housing. In one embodiment, the second mechanical assist device also comprises a tethering device configured to tether the second mechanical assist device to the inferior vena cava while the second mechanical assist device is in operation. The tethering device encloses a portion of the cannula. The tethering device may be operated selectively. For example, the tethering device is a balloon. The balloon may be inflated to partially occlude the inferior vena cava. Alternatively, the tethering device comprises a deployable arm that engages with the wall of the inferior vena cava. For example, the tethering device is a self-extending cage made of nitinol.

[0021] In some embodiments, the second mechanical auxiliary device is positioned such that the inlet is positioned where the renal vein connects to the inferior vena cava.

[0022] In some embodiments, each of the first and second mechanical support devices comprises a pressure sensor for measuring arterial and venous pressure, respectively. In one embodiment, the pressure sensor is integrated into each of the first and second mechanical support devices. For example, the first and second mechanical support devices are Impella® pumps equipped with differential pressure sensors or optical pressure sensors. In another embodiment, a separate pressure sensor wire or Swan-Ganz catheter is inserted along each of the first and second mechanical support devices. In yet another embodiment, one of the mechanical support devices includes an integrated sensor, while the other mechanical support device does not include an integrated sensor and is instead used in combination with a separate pressure sensor wire or Swan-Ganz catheter.

[0023] In some embodiments, when both the first and second mechanical auxiliary devices 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 embodiment, the difference increases by about 5%.

[0024] In another embodiment, a method for improving renal function in a patient includes the steps of inserting a first blood pump into the patient's heart and activating the first blood pump. The method further includes the steps of inserting a second blood pump into the patient's inferior vena cava and activating the second blood pump while the first blood pump is activating. The method also includes the steps of monitoring renal parameters and terminating the operation of the second blood pump when the renal parameters reach a target level. For example, the target level for the renal parameter is a function of aortic pressure. For example, the renal parameter is the creatinine level or ANP concentration in the blood, or renal venous pressure. In one embodiment, the target level for renal venous pressure is less than 15 mmHg. In another embodiment, the renal parameter is the pressure drop across the kidney.

[0025] In some embodiments, the kidney parameter is determined by measuring the arterial pressure and measuring the venous pressure, and calculating the pressure difference between the measured arterial pressure and the measured renal venous pressure. In some embodiments, the method for improving renal function in a patient also includes determining that the calculated pressure difference has reached a threshold value.

[0026] In some embodiments, the first blood pump communicates with a first controller, and the second blood pump communicates with a second controller. For example, the first and second controllers are Automated Impella Controller (registered trademark) (AIC). In one embodiment, the first controller and the second controller communicate to determine the pressure difference between the measured arterial pressure and the measured renal venous pressure.

Brief Description of the Drawings

[0027] The above and other objects and advantages will become apparent by considering the following detailed description in conjunction with the accompanying drawings; throughout the accompanying drawings, like reference numerals refer to like parts. [Figure 1] An exemplary renal excretion curve showing that urine output varies according to arterial pressure is shown. [Figure 2] An exemplary aspect of the system disclosed herein is shown. [Figure 3] An exemplary method disclosed herein is shown.

Modes for Carrying Out the Invention

[0028] Detailed explanation To ensure that the systems, methods, and devices described herein are understood in their entirety, certain exemplary embodiments are described. While the embodiments and features described herein are specifically described in conjunction with intracardiac pump systems, it should be understood that all components and other features outlined below may be combined with each other in any preferred manner and may be adapted and applied to other types of medical devices, such as electrophysiological testing and catheter ablation devices, angioplasty and stent placement 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, TAVR delivery systems, and cardiac treatment and cardiac support devices; such devices also include balloon pumps, cardiac support devices implanted using surgical incisions, and any other catheters and devices introduced intravenously or arterially.

[0029] The systems, methods, and devices described herein enable improvement of renal function by maintaining or increasing arterial pressure upstream of the kidney; maintaining or decreasing venous pressure downstream of the kidney; or a combination of both, in order to increase blood flow through the kidney and, consequently, increase renal output.

[0030] Figure 1 shows an exemplary renal output curve, illustrating how urine output fluctuates with arterial pressure. For example, as mentioned above, higher arterial pressure increases blood flow to the kidneys. Arterial blood carries humoral factors to the kidneys, and therefore, higher arterial pressure results in a larger volume of humoral factors reaching the kidneys and binding to receptors on the kidneys, thereby increasing renal function and urine output.

[0031] Figure 2 shows exemplary embodiments of system 200 configured to provide either similar or higher arterial pressure, similar or lower venous pressure, or a combination of both. Higher arterial pressure (e.g., input to an organ such as the kidney) results in increased blood flow through that organ. For example, in the case of the kidney, higher arterial pressure results in increased blood flow through the kidney, and consequently, increased urine output from the kidney. Similarly, lower venous pressure (pressure at the output of an organ, such as the output of the kidney) results in increased blood flow through that organ. For example, in the case of the kidney, higher arterial pressure results in increased blood flow through the kidney, and consequently, increased urine output from the kidney. A combination of higher arterial pressure (e.g., input to an organ such as the kidney) and lower venous pressure (pressure at the output of an organ, such as the output of the kidney) results in a similar or greater increase in blood flow through that organ. When the organ is the kidney, a combination of higher arterial pressure and lower venous pressure results in increased urine output from the kidney. System 200 comprises pump 202 and pump 222. For example, pumps 202 and 222 are Impella® pumps. Alternatively, pumps 202 and 222 are other mechanical circulatory support devices, such as expandable pumps, intra-aortic balloon pumps, or extracorporeal membrane oxygenation (ECMO).

[0032] Pumps 202 and 222 control the input and output to organs, such as the kidney 250 in Figure 2. For example, the kidney 250 may be the left or right kidney. In one embodiment, the combination of pumps 202 and 222 controls the input and output to both kidneys. For example, activating one or both blood pumps changes the flow quantity and flow rate of blood through organs such as the kidneys. For example, activating one or both blood pumps changes the flow quantity and flow rate of blood through the kidneys.

[0033] As shown in Figure 2, the pump 202 is Inside Housing 208 motor and rotor and,This is a first blood pump comprising a cannula 210, a distal extension 212, and a catheter 214. As shown in the embodiment in Figure 2, the pump 202 has a distal extension 212 located in the left ventricle, and a rotor and The rotor housing 208 is positioned within the aorta. When operating, the pump 202 reduces the load on the heart by drawing blood through the inlet 216, through the cannula 210, and through the housing 208 (also called the rotor shroud). The distal extension 212 acts to stabilize the pump 202 within the ventricle. For example, the distal extension 212 is pigtail or J-shaped. When operating, the pump 202 reduces the load on the left ventricle and increases the pressure in the aorta, thereby increasing the arterial pressure downstream. The pump 202 may operate at a range of speeds that result in a range of flow velocities and a corresponding increase in aortic pressure. For example, the pump 202 operates at a flow velocity of approximately 1.5 L / min to 6 L / min. In one embodiment, the pump 202 operates at a flow velocity of approximately 5 L / min. The pump 202 may be percutaneously inserted into the patient's body via the femoral artery or the subclavian vein.

[0034] As shown in Figure 2, the pump 222 is Inside Housing 228 motor and rotor and, Cannula 220 and distal extension 2 4 This is a second blood pump equipped with 2 and a catheter 224. As shown in the embodiment in Figure 2, pump 222 is placed in the inferior vena cava. When pump 222 is operating, it draws blood through the inlet 236, through the cannula 220, and out through the rotor housing 228 (also called the rotor shroud). Equipped with a rotor Rotor housing 228 teethLocated downstream of the inlet 236 within the inferior vena cava, the inlet 236 is also located within the inferior vena cava. In one embodiment, as shown, for example in Figure 2, the pump 222 includes a distal extension 242 that stabilizes the pump 222 within the inferior vena cava or at the junction between the inferior vena cava and the renal vein. For example, the distal extension 242 is pigtail or J-shaped. The pump 222 also includes a tethering mechanism 240 positioned on the cannula between the inlet 236 and the rotor housing 228 through which blood exits the pump. The tethering mechanism 240 may both tether the pump 222 to a desired position along the inferior vena cava and partially occlude the inferior vena cava to allow the pump 222 to operate across the tethering mechanism. For example, the tethering mechanism 240 tethers the pump 222 between approximately 1 and 5 centimeters downstream of the renal vein. In another embodiment, the anchoring mechanism 240 anchors the pump 222 approximately 2-3 centimeters downstream of the renal vein. In one embodiment, 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 position of the balloon on the cannula 220 are selected to achieve different levels of occlusion within the inferior vena cava. In another embodiment, the anchoring mechanism 240 is an expandable cage. For example, the anchoring mechanism 240 is a self-stretching cage (e.g., Nitinol) that is surrounded by a sheath for insertion and self-stretches once the sheath is removed in situ. The cage braces against the wall of the inferior vena cava to securely fix the pump 222 in place. In one embodiment, the cage may be tapered proximal and distal along the cannula to partially occlude the inferior vena cava and may be covered with a biocompatible cover material.

[0035] Partial occlusion of the inferior vena cava, combined with the operation of pump 222, which draws blood from its location within the inferior vena cava and / or renal vein to a location downstream of pump inlet 236, results in a pressure drop. The pressure drop may be measured as a pressure drop in the inferior vena cava upstream of pump 222 (e.g., immediately adjacent to the renal vein) or as a pressure drop in the renal vein. Alternatively, the pressure drop may be measured as a cross-renal drop between the arterial pressure entering the kidney and the venous pressure leaving the kidney (e.g., within the renal vein).

[0036] Pump 222 may be inserted percutaneously into the patient's body via the femoral artery or the subclavian vein. In one embodiment, pump 222 and pump 202 are inserted through different percutaneous access points. Alternatively, pump 222 and pump 202 are inserted through the same percutaneous access point (e.g., the subclavian vein).

[0037] In one embodiment, 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 embodiment, both pumps include a separate pressure sensor introduced on a pressure sensor wire, or a Swan-Ganz catheter. Alternatively, one of the pumps includes an integrated pressure sensor, and 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, where one side of the sensor is exposed to blood pressure above the outside of the inlet area, and the other side of the sensor is exposed to blood pressure inside the cannula 210. In this embodiment, the sensor generates an electrical signal proportional to the difference between two pressures, and this electrical signal is generated for display on a controller (e.g., an Automated Impella® controller). Alternatively, pump 202 may be introduced into the patient's body together with a Swan-Ganz catheter for measuring pressure. Similarly, the pump 222 may include an integrated pressure sensor for detecting pressure. For example, the pump 222 may include a differential pressure sensor in which one side of the sensor is exposed to blood pressure above the outside of the inlet area and the other side of the sensor is exposed to the pressure of blood inside the cannula 220. In this embodiment, the sensor generates an electrical signal proportional to the difference between the two pressures, and this electrical signal is generated for display on a controller (e.g., an Automated Impella® controller). Alternatively, the pump 222 may be introduced into the patient's body together with a Swan-Ganz catheter for measuring pressure.

[0038] Each pump (e.g., pumps 202 and 222) may be connected to a controller, such as an Automated Impella Controller®, which receives data from the pump and its associated sensors (e.g., either integrated or separate sensors) and generates information about cardiac output and / or renal output for display to the user (e.g., a medical professional). As will be described later with respect to the embodiment in Figure 3, the information from the controller is used to determine whether and when to stop one or more pumps.

[0039] As will be discussed later with respect to Figure 3, by operating pump 222 while pump 202 is operating, both the arterial pressure input to kidney 250 and the venous pressure output from kidney 250 can be adjusted. At least one advantage of this dual-pump operation is that both cardiac output and arterial pressure input to kidney 250 can be increased and / or the venous pressure leaving kidney 250 can be reduced. Therefore, operating pump 202 while pump 222 is operating increases blood flow to the kidney and increases the amount of humoral factors reaching the kidney. Operating pump 222 while pump 202 is operating increases blood flow leaving the kidney. At least one advantage of this dual-pump operation is that urine output can be increased and stressors can be removed; stressors include, for example, those resulting from surgery.

[0040] Figure 3 shows an exemplary method 300 for improving renal function. In step 302, a first blood pump (e.g., pump 202 in Figure 2) is inserted into the patient's heart. In step 304, the first blood pump is activated to increase aortic pressure. In step 306, a second blood pump (e.g., pump 222 in Figure 2) is inserted into the patient's inferior vena cava. After the second blood pump is inserted, a tethering mechanism is positioned (e.g., tethering mechanism 240 in Figure 2). For example, the tethering mechanism is a balloon surrounding a portion of the pump cannula (e.g., cannula 220 of pump 222 in Figure 2). In this embodiment, the balloon surrounding the portion of the pump is inflated to tether the pump in the inferior vena cava and partially occlude the inferior vena cava. In step 308, the second blood pump is activated while the first blood pump is operating. In step 312, the system determines whether the target renal parameter (e.g., blood pressure reduction in the renal vein) has been achieved at a location in the patient's renal vein or inferior vena cava. If the decision in step 312 is that the target renal parameter (e.g., a decrease in blood pressure in the renal vein) has been achieved, the operation of the second blood pump may be stopped (step 314). If the decision in step 312 is that the target renal parameter (e.g., a decrease in blood pressure in the renal vein) has not been achieved, a second decision is made on whether to adjust the operation of the first blood pump and / or the second blood pump (step 310). For example, the speed of the first blood pump (e.g., pump 202 in Figure 2) may be modified (e.g., increased or decreased) independently of the speed of the second blood pump. In one embodiment, 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 speed of the second blood pump (e.g., pump 222 in Figure 2) may be modified (e.g., increased or decreased) independently of the speed of the first blood pump. In another embodiment, the speeds of both the first and second blood pumps may be increased. If the decision in step 310 indicates that no adjustments are needed, the method returns to determining whether the target kidney parameters have been achieved (step 312).For example, the target kidney parameter may be a target pressure drop in the renal vein pressure, or a target pressure drop across the kidney. For example, it may be necessary to operate the first and second blood pumps for a longer period of time to achieve an effect on either or both arterial and venous pressure. Alternatively, if the decision in step 310 requires adjustment to the operation of either or both of the first and second blood pumps, the method returns to step 308, where the first and second blood pumps are operated simultaneously.

[0041] For example, a pump controller (e.g., the controller for pumps 222 and / or 202 in Figure 2) is configured to operate one or both auxiliary devices (e.g., pumps 222 and / or 202 in Figure 2) at their respective rates to increase blood flow from the heart and to stimulate the production of at least one humoral factor that binds to renal receptors or receptors on another organ, in order to stimulate and / or regulate urine production and urine synthesis from the kidneys. In one embodiment, as described above with respect to Figure 2, both pumps (pumps 222 and 202) are connected to a single controller. The controller may receive data regarding renal parameters. For example, the renal parameter is the pressure drop at the exit of the kidney. Alternatively, the renal parameter is the pressure drop across the kidney. In another embodiment, the renal parameter is the blood creatinine level or ANP concentration. In one embodiment, the controllers for both pumps communicate with each other.

[0042] In one embodiment, the controller may also compare the renal parameters to a threshold for the renal parameters. For example, the controller may continuously compare the renal parameters to the threshold in near real-time. Alternatively, the controller may perform the comparison periodically. The threshold may be entered by the user. Alternatively, the threshold may be retrieved from a database by the controller. For example, the database is a remote database with known clinical data on target renal parameter values. In one embodiment, the controller is configured to generate an indicator for display that a threshold for the renal parameters has been reached. For example, the controller may generate an alarm. In another embodiment, the controller sends a message to the physician. In one embodiment, the physician may turn off one or more of the pumps based on monitoring of the renal parameters. For example, the physician may turn off pump 222 while keeping pump 202 running when a renal parameter (e.g., pressure in the renal vein) reaches a threshold. In another embodiment, the controller detects that the renal parameters have reached a threshold and automatically turns off one or more of the pumps. One advantage of being able to decide when to turn off another pump is that it allows the patient to be safely weaned off support and that it can improve organ function (e.g., kidney function) without damaging the organ (e.g., kidneys) by exposing it to high blood pressure for longer than necessary.

[0043] The foregoing is merely illustrative of the principles of this disclosure, and the systems, methods, and devices of the present invention may be implemented in forms other than those described herein, which are presented for illustrative purposes only, not limitation. It should be understood that, although the systems, methods, and devices disclosed herein are shown for use in systems for intracardiac pumps, they may also be applicable to systems, methods, and devices for other implantable cardiac pumps or implantable cardiac assist devices.

[0044] Those skilled in the art will be able to conceive of variations and modifications after reviewing this disclosure. The various features described or illustrated above, including their components, may be combined or integrated into other systems. Furthermore, certain features may be omitted or not implemented. The various embodiments described or illustrated above may be combined in any manner.

[0045] Examples of changes, substitutions, and modifications are verifiable to those skilled in the art and can be made without departing from the scope of the information disclosed herein. All references herein are incorporated by reference in their entirety and constitute part of this application.

Claims

1. A first blood pump, positioned and operated within the patient's heart, configured to relieve the load on the ventricles, atria, or both atria and ventricles, or both atria and both ventricles; A second blood pump, positioned within the inferior vena cava of the patient and configured to operate within the inferior vena cava of the patient by pumping blood from the inferior vena cava of the patient; The first blood pump and the second blood pump are configured to achieve a target pressure reduction in the patient's renal vein when operated simultaneously. A controller configured to operate both the first blood pump and the second blood pump, It is equipped with, The aforementioned controller Receiving arterial pressure from the first blood pump and venous pressure from the second blood pump; Determining that the pressure drop in the renal vein of the patient is below the target pressure drop in the renal vein; and To achieve the target pressure reduction in the renal vein, the operation of at least one of the first blood pump and the second blood pump is adjusted. It is configured to do the following: The second blood pump, Pump motor and; The pump housing located distal to the pump motor and surrounding the rotor; A cannula extending distally to the pump housing; The system comprises a tethering device configured to tether the second blood pump to the inferior vena cava of the patient while the second blood pump is in operation, The aforementioned tethering device is a balloon surrounding a portion of the cannula, and the balloon is configured to partially occlude the patient's inferior vena cava when inflated. The second blood pump is positioned such that its inlet is positioned where the patient's renal vein connects to the patient's inferior vena cava. A system designed to improve patients' kidney function.

2. The system according to claim 1, wherein the target pressure drop is a predetermined amount sufficient to increase urine production by the patient's kidneys.

3. A control unit configured to operate the first blood pump at a predetermined rate that increases blood flow from the heart and stimulates the production of at least one humoral factor that binds to renal receptors or receptors in another organ, in order to stimulate urine production and regulate the contents of urine from the kidneys. The system according to claim 1, further comprising:

4. The system according to claim 1, wherein the first blood pump further comprises a first pressure sensor configured to measure arterial pressure.

5. The system according to claim 4, wherein the second blood pump comprises a second pressure sensor configured to measure venous pressure.

6. The system according to claim 5, wherein the difference between the measured venous pressure and the measured arterial pressure increases when both the first blood pump and the second blood pump are operating simultaneously.

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