Using a heart assist device to improve kidney function

Abstract

Systems and methods for improving renal function. A first mechanical circulatory support system (MCS) is introduced into the patient's heart, and a second mechanical circulatory support system is introduced into the patient's inferior vena cava or renal vein. The second mechanical circulatory support system operates while the first mechanical circulatory support system is operating. Renal parameters are monitored during operation of the first mechanical circulatory support system and the second mechanical circulatory support system. The combined operation of the two mechanical circulatory support systems results in changes in renal parameters (e.g., a pressure drop in the renal vein), indicating an improvement in renal function. Once it is determined that the renal parameters are below a target threshold, the operation of the second mechanical circulatory support device is stopped.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application Ser. No. 16 / 406,896, filed May 8, 2019, entitled “Use of Cardiac Assist Device to Improve Kidney Function,” the entire contents of which are incorporated herein by reference. Background Art

[0003] The kidneys play a central role in controlling the body's arterial fluid pressure. They regulate renal output by altering the excretion of water (diuresis) and by altering the excretion of salt (natriuresis). This regulation is reflected in the renal output curve ( Figure 1 ) in which urine output varies according to arterial pressure. Under normal circumstances, the kidneys are able to automatically adjust themselves, increasing or decreasing urine output and renal blood flow in response to increases or decreases in blood pressure or blood flow rate or changes in salt concentration. However, damage or other changes in renal function may impair automatic adjustment. For example, impaired renal function increases arterial pressure and increases the amount of water and salt in the circulation. Conversely, heart failure or coronary artery disease can significantly reduce cardiac output, which in turn reduces blood flow to the renal arteries and impairs urine output.

[0004] 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 the glomerular filtration rate (GFR) and renal output, an acute condition called oliguria (a sharp decrease in urine output).

[0005] Particularly when undergoing surgery, patients with impaired heart function and / or pre-existing kidney conditions may require heart bypass surgery. Due to the stress of surgery, their hearts release stressors through their bodies. The type and amount of stressors released by the heart may vary depending on the length or nature of the surgery (e.g., CABG, valve replacement, valve repair, etc.). Monitor the patient's renal output as an indicator of recovery during or immediately after surgery. For example, an increase in creatinine or a decrease in filtration rate can be monitored to measure the patient's recovery. Current systems that provide flat-line pressure (e.g., ECMO) do not improve renal function, but may damage the kidneys by placing them under high pressure. Monitoring renal output as an indicator of recovery is particularly important for high-risk heart patients (e.g., STEMI, CS, PCI) who also often suffer from acute kidney disease, failure, or disorder.

[0006] It is desirable to provide improved methods and systems that can improve renal function, particularly in the case of vascular disease. Specifically, it is desirable to provide a system or method that can provide one or more of improved renal excretion, reduced nephrotoxicity of various medicaments, and controlled renal autoregulation. It is desirable to provide a system or method that can increase the flow rate flowing into the kidneys to increase urine excretion and the processing of undesirable stressors being excreted from the body. It is also desirable to provide a system or method that can monitor renal parameters to determine whether the flow rate flowing into the kidneys is sufficient to make it no longer necessary to increase the flow rate flowing into the kidneys. Summary of the invention

[0007] Provided herein are methods and systems for solving one or more of the aforementioned problems. Renal output can be increased by increasing blood flow through the kidneys. Blood flow through the kidneys can be regulated by reducing the heart 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 the two-selected to maintain or increase the pressure gradient across the kidneys. At least one advantage of reducing the heart load and increasing the arterial pressure upstream of the kidneys is to increase the release of one or more humoral factors, which act on kidney 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 combined with the kidneys advantageously improves 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 the blood flow (including humoral factors) through the kidneys, thereby increasing renal output. The methods and systems provided herein also solve 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 that once the patient has fully recovered renal function, it can be determined that the second blood pump can be turned off. In one example, the first blood pump and the second blood pump may 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 any of the techniques identified in Appendix A.

[0008] In some embodiments, a method for regulating the renal function of a patient 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, a blood pump can be introduced into the left heart or right heart of the patient. In left ventricular applications, 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 so 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 into any position that reduces the heart load and maintains or increases cardiac output. The method also includes inserting a second mechanical assist device (e.g., a second blood pump) into the inferior vena cava of the patient and operating the second blood pump when the first blood pump is running. For example, the second blood pump is placed near the inferior vena cava or in the inferior vena cava, or in the inlet of the inferior vena cava, or in the renal vein. The inlet of the second blood pump can be placed at the junction between the renal vein and the inferior vena cava of the patient. In another example, the second blood pump is configured to partially occlude the inferior vena cava so that the operation of the second blood pump produces a pressure drop upstream of the second blood pump inlet (between the pump and the kidney, including in the renal vein). In these embodiments, the operation of the first blood pump and the second blood pump achieves a target pressure drop at a position in the patient's renal vein or the inferior vena cava. Therefore, 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, and the second pump located at the distal (downstream) side of the kidney relieves the kidney load and thereby reduces the pressure in the renal vein. In other adaptations, one of the blood pumps is continuously operated, and 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 different amounts of time at different speeds. For example, the first blood pump can operate at a speed of about 40,000rpm for up to 6 hours, and the second blood pump can operate at a speed of 30,000rpm for about 3 hours. Alternatively, the first blood pump and the second blood pump can operate at similar speeds in the same time period.

[0009] At least one advantage of using the first blood pump is to reduce the load of the left ventricle or right ventricle (or both) or the left atrium or right atrium (or both) of the heart, thereby not only improving the blood circulation through the renal artery, but also stimulating the release of one or more humoral factors acting on kidney receptors (at or near the renal artery or glomerulus or any nephron component) or other receptors in vascular tissue. This stimulation improves kidney output, helps to manipulate and maintain kidney autoregulation, and also helps to protect the kidney from toxicity and damage. Deployment and operation of the first blood pump can be used to reduce the load of the left ventricle to reduce left ventricular pressure (and left atrial pressure) and capacity, or reduce the load of the right ventricle and reduce right ventricular pressure (and right atrial pressure) and capacity, or both.

[0010] At least one advantage of unloading the ventricles by pumping blood from the ventricles into the arteries and away from the heart (aorta or pulmonary artery) is a general increase in arterial pressure, which increases pulsatility of the vasculature and increases blood flow into the renal arteries and kidneys, thereby increasing glomerular filtration rate. Another advantage of a pump is that it increases diastolic pressure—the pressure at which the kidneys receive the most blood flow—without having to keep the kidneys under constant high pressure. Another advantage of pumps that reduce the workload of the heart is to upregulate the production of one or more humoral factors in cardiac tissue (or arterial tissue) and release such one or more factors into the circulation. Most humoral factors are produced in the left atrium of the heart-reducing the workload of the heart can decompress the left atrium and promote the production of humoral factors (e.g., the production of ANP). The humoral factors that flow to the receptors (one or more) of the kidneys and / or other organs will actuate the receptors of the kidneys or other (one or more) organs and stimulate the increase of the organ function. The humoral factors that flow to the kidneys will actuate the kidney receptors and stimulate the increase of urine discharged from the kidneys. For example, the released humoral factors are combined with kidney receptors or other organ receptors. When the humoral factors arrive at the renal artery (and the nephron of the kidney), the humoral factors will combine with one or more kidney receptors, and thereby actuate the incoming and / or outgoing arterioles directly to face the mesangial cells in the glomerulus, thereby increasing or reducing renal blood flow. Even if the renal perfusion pressure changes, increasing renal blood flow will also increase or decrease or maintain the glomerular filtration rate. In addition, or alternatively, humoral factors can activate the tubular wall to excrete and / or absorb or reabsorb glucose, salts or other electrolytes into the urine, so that water from the surrounding vasculature and tissues will also passively follow changes in electrolyte levels in the urine, thereby causing corresponding adjustments (increase / decrease / maintenance of urine output and urine content) even in the face of changing renal perfusion pressure and changes in blood electrolytes, glucose and trace elements. Receptors in the kidney implicated by this effect can include atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), NT-proBNP, catecholamine receptors, adenosine receptors, angiotensin receptors (AT1, AT2), prostaglandin receptors, alpha-keto-glutarate receptors, glutamate receptors, just to name a few. For example, renal receptors are located in the nephron or tubule or medulla or cortex of the kidney.

[0011] In some embodiments, a first blood pump is operated in the heart to maintain or increase arterial pressure in the renal artery. In other embodiments, a second blood pump is operated in the inferior vena cava to maintain or reduce renal venous pressure. For example, in one embodiment, the first blood pump is operated to increase arterial pressure, while the second blood pump is operated to reduce renal venous pressure. In another example, the first blood pump is operated to maintain arterial pressure, while the second blood pump is operated to reduce renal venous pressure. In yet another example, the first blood pump is operated to increase arterial pressure, while the second blood pump is operated to maintain renal venous pressure.

[0012] In some embodiments, a target pressure drop at a location in the patient's renal vein or inferior vena cava increases blood flow through the kidneys and improves 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 may vary depending on the baseline of the 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 is achievable, 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, a device that provides increased diastolic pressure. The time required to pump will be shorter than with an intra-aortic balloon pump or other types of mechanical circulation systems.

[0013] In some embodiments, the target pressure drop corresponds to a drop in blood pressure 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 may vary depending on the baseline of the 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, a device that provides increased diastolic pressure. The time required to pump will be shorter than with an intra-aortic balloon pump or other types of mechanical circulation systems.

[0014] In some embodiments, combined operation of the first blood pump and the second blood pump directs the flow of humoral factors to renal receptors to stimulate increased urine output from the kidneys.

[0015] In some embodiments, a first blood pump (e.g., The pump includes a pump motor and a pump housing distal to the pump motor. The pump housing surrounds the rotor, and the cannula extends distally from the pump housing. In some examples, the atraumatic extension extends distally from the cannula. For example, the atraumatic extension is braided.

[0016] In some embodiments, the second blood pump includes a pump motor and a pump housing distal to the pump motor. The pump housing surrounds the rotor, and the cannula extends distally from the pump housing. In some examples, the atraumatic extension extends distally from the cannula. For example, the atraumatic extension is braided.

[0017] In some embodiments, the second pump is positioned within the inferior vena cava such that the distal tip of the atraumatic extension extends to a point within the inferior vena cava adjacent to the outlet of the renal vein. For example, the distal tip of the atraumatic extension extends between 0-2 centimeters from the point where the renal vein connects to the inferior vena cava. At least one benefit of the distal tip extending between 0-2 centimeters from the point where the renal vein connects to the inferior vena cava is the ability to stabilize the inlet of the pump at a desired location adjacent to the renal vein.

[0018] In other embodiments, a system for improving renal function includes 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 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 are blood pumps. In another example, the second mechanical assist device is a balloon pump.

[0019] In some embodiments, the system for improving renal function further comprises a controller (e.g., an automatic Impella controller (Automated Impella )) is configured to receive arterial pressure from a first mechanical assist device and venous pressure from a second mechanical assist device. The controller determines whether a pressure drop in the renal vein is close to a target pressure drop in the renal vein and controls adjustment of operation of at least one of the first mechanical assist device and the second mechanical assist device. In one example, the adjustment of operation helps achieve the target pressure drop in the renal vein. In another example, when the target pressure drop is achieved, the adjustment of operation includes shutting down one or both of the mechanical assist devices. In one example, the system includes two controllers (e.g., two automatic Impella controllers ), each controller is associated with a mechanical auxiliary device (e.g. pumps) and receive data from their respective mechanical assist devices.

[0020] 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 corresponding rates to increase blood flow from the heart and stimulate the production of at least one humoral factor that binds to a kidney receptor or another organ receptor to stimulate and / or regulate urine volume and urine composition from the kidney.

[0021] 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 the rotor, and the cannula extends distal to the pump housing. In an example, the second mechanical assist device also includes an anchoring device, which is configured to anchor the second mechanical assist device to the inferior vena cava when the second mechanical assist device is in operation. 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 a deployable arm that engages with the wall of the inferior vena cava. For example, the anchoring device is a nitinol self-expanding cage.

[0022] In some embodiments, the second mechanical assist device is positioned to have an access port at a location where the renal vein connects to the inferior vena cava.

[0023] 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 each a pressure differential sensor or an optical pressure sensor. In another example, a separate pressure sensor line or Swan-Ganz catheter is inserted with each of the first and second mechanical assist devices. In yet another example, one of the mechanical assist devices includes an integrated sensor, while the other of the mechanical assist devices does not - but is used in conjunction with a separate pressure sensor line or Swan-Ganz catheter.

[0024] In some embodiments, when both the first mechanical assist device and the second mechanical assist device are operated 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%.

[0025] In yet another embodiment, a method for improving renal function in a patient includes inserting a first blood pump into the 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 a renal parameter, and when the renal parameter reaches a target level, terminating the operation of the second blood pump. For example, the target level of the renal parameter is a function of aortic pressure. For example, the renal parameter is a creatinine level or an ANP concentration or a renal venous pressure in the blood. In one example, the target level of the renal venous pressure is less than 15 mmHg. In another example, the renal parameter is a pressure drop across the kidney.

[0026] In some embodiments, the renal parameter is determined by measuring arterial pressure and measuring 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 renal function in a patient further comprises determining that the calculated pressure difference has reached a threshold.

[0027] 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 controller and the second controller are automatic Impella controllers. (AIC). In one embodiment, the first controller communicates with the second controller to determine a pressure difference between the measured arterial pressure and the measured renal venous pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other objects and advantages will become apparent from the following description of the specific embodiments considered in conjunction with the accompanying drawings, in which like reference numerals refer to like parts throughout, and in which:

[0029] Figure 1 An illustrative renal output curve is shown in which urine output varies as a function of arterial pressure;

[0030] Figure 2 shows an illustrative embodiment of the system disclosed herein; and

[0031] Figure 3 An illustrative method disclosed herein is shown. DETAILED DESCRIPTION

[0032] In order 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 for use 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 applicable and applied to other types of medical devices, such as electrophysiological research and catheter ablation devices, angioplasty and stent devices, angiographic 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 therapy and heart assist devices (including balloon pumps), heart assist devices implanted using surgical incisions, and any other venous or arterial based catheters and devices.

[0033] By maintaining or increasing arterial pressure upstream of the kidneys, maintaining or decreasing venous pressure downstream of the kidneys, or a combination of both, the systems, methods, and devices described herein provide improvements in renal function by increasing blood flow through the kidneys and thereby increasing renal output.

[0034] Figure 1 An illustrative renal output curve is shown, in which urine output varies according to arterial pressure. For example, as described above, higher arterial pressure increases blood flow to the kidneys. Arterial blood carries humoral factors to the kidneys, so that higher arterial pressure results in an increased amount of humoral factors that reach the kidneys and bind to receptors on the kidneys, thereby enhancing renal function and increasing urine output.

[0035] Figure 2 An illustrative embodiment of a system 200 is shown, which is configured to provide similar or higher arterial pressures, similar or lower venous pressures, or a combination of the two. A higher arterial pressure (into an organ such as the kidney) will result in an increase in blood flow through the organ. For example, for the kidney, a higher arterial pressure will result in an increase in blood flow through the kidney and, in turn, an increase in renal urine output. Similarly, a lower venous pressure (at the organ's discharge, such as at the kidney's discharge) will result in an increase in blood flow through the organ. For example, for the kidney, a higher arterial pressure will result in an increase in blood flow through the kidney and, in turn, an increase in renal urine output. The combination of a higher arterial pressure (into an organ such as the kidney) and a lower venous pressure (at the organ's discharge, such as at the kidney's discharge) will result in a similar or greater increase in blood flow through the organ. When the organ is the kidney, the combination of a higher arterial pressure and a lower venous pressure will result in an increase in renal urine output. System 200 includes a pump 202 and a pump 222. For example, pumps 202 and 222 are Pumps. Alternatively, pumps 202 and 222 are other mechanical circulatory assist devices, such as an expandable pump, an intra-aortic balloon pump, or an extracorporeal membrane oxygenation system (ECMO).

[0036] Pumps 202 and 222 control the flow of fluid into an organ (e.g., Figure 2 In one example, the combination of pump 202 and pump 222 controls the input and output into both kidneys. For example, operating one or both blood pumps changes the flow rate and flow velocity of blood through an organ (e.g., kidney). For example, operating one or both blood pumps increases the flow rate and flow velocity of blood through the kidneys.

[0037] like Figure 2 As shown, pump 202 is a first blood pump having a cannula 210, a distal extension 212, a catheter 214, a motor 204 in a housing 208, and a rotor 206. Figure 2As shown in the example of, pump 202 is placed so that the distal extension 212 is in the left ventricle, and the rotor 206 and the rotor housing 208 are in the aorta. When in operation, the pump 202 draws blood through the inlet 216, passes through the cannula 210 and is discharged through the housing 208 (also referred to as the rotor shield), 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 a braid or j-shaped. When in operation, the pump 202 reduces the left ventricle load and increases the pressure in the aorta, thereby increasing the arterial pressure downstream. The pump 202 can be operated at a series of speeds, resulting in a series of flow rates and an increase in the associated aortic pressure. For example, the pump 202 operates at a flow rate between about 1.5L / min and 6L / min. In one example, the pump 202 operates at a flow rate of about 5L / min. The pump 202 can be inserted into the patient's body percutaneously via the femoral artery or via the subclavian vein.

[0038] As shown in FIG. 2 , pump 222 is a second blood pump having a cannula 220, a distal extension 242, a catheter 224, a motor 223 in a housing 228, and a rotor 226. Figure 2 As shown in the example of , pump 222 is placed in the inferior vena cava. When operating, pump 222 draws blood through inlet 236, through cannula 220, and out through rotor housing 228 (also called rotor shield). Rotor housing 228 with rotor 226 is in the inferior vena cava, downstream of inlet 236, which is also in the inferior vena cava. In one example, such as Figure 2As shown, pump 222 includes a distal extension 242, which stabilizes pump 222 in the inferior vena cava, or at the connection between the inferior vena cava and the renal vein. For example, distal extension 242 is braided or j-shaped. Pump 222 also includes an anchoring mechanism 240, which is positioned on the cannula between inlet 236 and rotor housing 228, and blood leaves the pump through the cannula. Anchoring mechanism 240 can both anchor pump 222 at a desired position along the inferior vena cava and partially occlude the inferior vena cava to allow pump 222 to operate on the entire anchoring mechanism. For example, anchoring mechanism 240 anchors pump 222 between about 1-5 cm downstream of the renal vein. In another example, anchoring mechanism 240 anchors pump 222 between about 2-3 cm downstream of the renal vein. In one example, anchoring mechanism 240 is a balloon that can be selectively expanded 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 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 bears against the wall of the inferior vena cava and fixes the pump 222 in place. In one example, the fusion device can taper proximally and distally along the cannula and be covered by a biocompatible covering material to partially occlude the inferior vena cava.

[0039] The partial occlusion of the inferior vena cava combined with the operation of the pump 222 draws blood from a location within the inferior vena cava and / or the renal vein to a location downstream of the pump inlet 236, resulting in a pressure drop. The pressure drop can be measured as a pressure drop in the inferior vena cava upstream of the pump 222 (e.g., near the renal vein), or as a pressure drop in the renal vein. Alternatively, the pressure drop can be measured as a drop across the kidney between the arterial pressure entering the kidney and the venous pressure exiting the kidney (e.g., in the renal vein).

[0040] Pump 222 can be inserted into the patient's body percutaneously via the femoral artery or via the subclavian vein. In one example, 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., subclavian vein).

[0041] 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 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, one side of which is exposed to the blood pressure outside the inlet area and the other side of which is exposed to the blood pressure inside cannula 210. In this example, the sensor generates an electrical signal that is proportional to the difference between the two pressures, and the electrical signal is generated to be detected by a controller (e.g., an automatic Alternatively, pump 202 may be introduced into the patient along 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 with one side of the sensor exposed to the blood pressure outside the inlet region and the other side of the sensor exposed to the blood pressure inside cannula 210. In this example, the sensor generates an electrical signal that is proportional to the difference between the two pressures, and the electrical signal is generated to be displayed on a controller (e.g., an automatic Alternatively, the pump 222 may be introduced into the patient along with a Swan-Ganz catheter for measuring pressure.

[0042] Each pump (e.g., pumps 202 and 222) may be connected to an automatic Impella controller such as A controller that receives data from the pump and sensors associated with the pump (e.g., integrated sensors or separate sensors) and generates information about cardiac output and / or renal output for display to a user (e.g., a medical professional). Figure 3 As described in the example of FIG. 1 , information from a controller is used to determine whether and when to stop operation of one or more pumps.

[0043] As follows about 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 cardiac output and arterial pressure input to kidney 250, but also / or reduce venous pressure out of kidney 250. Thus, 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 out of the kidney. At least one advantage of this dual pump operation is the ability to increase urine output and remove any stress factors, including, for example, stress factors caused by surgery.

[0044] Figure 3 An illustrative method 300 for improving renal function is shown. In step 302, a first blood pump (e.g., Figure 2 In step 304, the first blood pump is operated to increase aortic pressure. In step 306, a second blood pump (e.g., Figure 2 After the second blood pump is inserted, an anchoring mechanism (e.g., Figure 2 For example, the anchoring mechanism is an anchoring mechanism that surrounds the pump cannula (e.g., Figure 2 The balloon surrounding the portion of the cannula 220 of the pump 222 in the inferior vena cava is inflated. In this example, the balloon surrounding the portion of the pump is inflated so 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 drop in blood pressure in the renal vein) has been achieved at a location in the patient's renal vein or inferior vena cava. If it is determined at step 312 that the target renal parameter (e.g., a drop 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 drop in blood pressure in the renal vein) has not been achieved, a second determination is made whether to adjust operation of the first blood pump and / or adjust operation of the second blood pump (step 310). For example, the first blood pump (e.g., Figure 2 The speed of the first blood 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 about 1 L / min. Alternatively, the speed of the first blood pump is increased by about 2 L / min. Similarly, the speed of 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 pressure, 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 achieve an effect on arterial pressure, venous pressure, or both. Conversely, if it is determined in step 310 that the operation of either or both of the first blood pump and the second blood pump needs to be adjusted, the method returns to step 308, wherein the first blood pump and the second blood pump both operate simultaneously.

[0045] For example, a pump controller (e.g., Figure 2 The controller of pump 222 and / or pump 202) is configured to operate one or both auxiliary devices (e.g., Figure 2 Pump 222 and / or pump 202) to increase blood flow from the heart and stimulate the production of at least one humoral factor that binds to a kidney receptor or another organ receptor to stimulate and / or regulate urine volume and urine composition from the kidney. In one example, as described above with respect to Figure 2 As discussed, both pumps (pump 222 and pump 202) are connected to a single controller. The controller(s) may receive data regarding a renal parameter. For example, the renal parameter is the pressure drop at the renal 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.

[0046] In one example, the controller(s) may also compare the renal parameter with a threshold value of the renal parameter. For example, the controller(s) may continuously compare the renal parameter with the threshold value in near real time. Alternatively, the controller(s) may compare periodically. The threshold value may be input by a user. Alternatively, the controller may retrieve the threshold value from a database. For example, the database is a remote database using known clinical data about the target renal parameter value. In one example, the controller(s) is configured to generate an indicator for display that the threshold value of the renal parameter has been reached. For example, the controller(s) may generate an alarm. In another example, the controller(s) sends a message to a doctor. In one example, the doctor may monitor and shut down one or more of the pumps based on the renal parameter. For example, once a renal parameter (e.g., pressure in the renal vein) has reached a threshold value, the doctor may shut down pump 222 while maintaining the operation of pump 202. In another example, the controller(s) detects that the renal parameter has reached a threshold value and automatically shuts down one or more pumps. At least one advantage of being able to determine when to turn off one or more pumps is the ability to safely wean a patient off support and to improve an organ (e.g., kidney function) without damaging the organ by subjecting it to high blood pressure for a longer period of time than necessary.

[0047] The foregoing is merely illustrative of the principles of the present disclosure, and the systems, methods, and devices may be practiced by other embodiments than those described, which are presented for purposes of illustration and not limitation. It should be understood that the systems, methods, and devices disclosed herein, while shown for use in a system for an intracardiac heart pump, may be applied to systems, methods, and devices for other implantable heart pumps or implantable heart assist devices.

[0048] After reading this disclosure, those skilled in the art will appreciate variations and modifications. The various features described or illustrated above (including any components thereof) may be combined or integrated in other systems. In addition, certain features may be omitted or not implemented. The various embodiments described or illustrated above may be combined in any manner.

[0049] Examples of changes, substitutions, and alterations are ascertainable 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 incorporated by reference in their entirety and become a part of this application.

Claims

1. A system for improving renal function in a patient, comprising: a first mechanical circulatory support device configured to be positioned within a patient's heart and to operate within the heart to unload one ventricle, unload one atrium, unload one atrium and one ventricle, or unload both atria and both ventricles; a second mechanical circulatory support device configured to be positioned within the inferior vena cava of the patient and to operate within the inferior vena cava by pumping blood within the inferior vena cava; a controller configured to operate both the first mechanical circulatory support device and the second mechanical circulatory support device; as well as a control unit configured to operate the first mechanical circulatory support device at a rate that increases blood flow from the heart and stimulates 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, Wherein the first mechanical circulatory support device and the second mechanical circulatory support device are configured to achieve a target pressure drop in a renal vein of the patient when operated simultaneously.

2. The system of claim 1, wherein the controller is configured to: receiving arterial pressure from the first mechanical circulatory support device and venous pressure from the second mechanical circulatory support device, determining that the pressure drop in the renal vein is less than the target pressure drop in the renal vein; and Operation of at least one of the first mechanical circulatory support device and the second mechanical circulatory support device is adjusted to achieve the target pressure drop in the renal vein.

3. The system of claim 1, wherein the target pressure drop is sufficient to increase the amount of urine produced by the patient's kidneys.

4. The system of claim 1, wherein the first mechanical circulatory support device and the second mechanical circulatory support device are blood pumps.

5. The system of claim 1, wherein the second mechanical circulatory support device comprises: Pump motor; a pump housing distal to the pump-motor, the pump housing enclosing a rotor; a cannula extending distally of the pump housing; as well as An anchoring device is configured to anchor the second mechanical circulatory support device to the inferior vena cava while the second mechanical circulatory support device is operating.

6. The system of claim 5, wherein the anchoring device is a balloon surrounding a portion of the cannula.

7. The system of claim 6, wherein the balloon is configured to partially occlude the inferior vena cava when inflated.

8. The system of claim 1, wherein the second mechanical circulatory support device is positioned to have an access port at a location where the renal vein connects to the inferior vena cava.

9. The system of claim 1, the first mechanical circulatory support device further comprising a first pressure sensor, wherein the first pressure sensor is configured to measure arterial pressure.

10. The system of claim 9, the second mechanical circulatory support device comprising a second pressure sensor, wherein the second pressure sensor is configured to measure venous pressure.

11. The system of claim 10, wherein the difference between the measured venous pressure and the measured arterial pressure increases when both the first mechanical circulatory support device and the second mechanical circulatory support device are operating simultaneously.

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