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FLOW RESTRICTING INTRAVASCULAR DEVICES FOR TREATING EDEMA

20220104828 ยท 2022-04-07

    Inventors

    Cpc classification

    International classification

    Abstract

    This disclosure relates to a catheter with a fluid flow restrictor (e.g., a balloon) that includes a flow path. The catheter is useful for creating, and maintaining, an area of reduced pressure within a blood vessel for removing excess fluid from a patient's body. In particular, the catheter is dimensioned for insertion into a blood vessel and includes a fluid flow restrictor that, when deployed, partially occludes the blood vessel. Pressure is reduced within the blood vessel downstream of the occlusion. The flow path allows some blood to flow past the restrictor, which prevents the blood vessel from stretching due to excessive pressure buildup, thereby allowing the area of reduced pressure to be maintained for extended periods of time.

    Claims

    1. A catheter comprising: a catheter body; and a restrictor operably coupled to the catheter body, wherein the restrictor comprises a retracted and a deployed configuration, and in the deployed configuration, an exterior surface of the restrictor is shaped to form at least one flow path along the exterior surface of the restrictor.

    2. The catheter of claim 1, wherein the flow path comprises at least two inflection points formed by the exterior surface of the restrictor.

    3. The catheter of claim 2, wherein each of the inflection points defines a transition region between a convex surface to a concave surface.

    4. The catheter of claim 2, wherein each of the inflection points are defined by a change in curvature around a circumference of the exterior surface of the restrictor.

    5. The catheter of claim 1, wherein the at least one flow path is disposed between two inflection points defining a concave surface for promoting fluid flow.

    6. The catheter of claim 1, wherein, when the restrictor is deployed inside a blood vessel, the flow path is formed between the exterior surface of the restrictor and a wall of the blood vessel.

    7. The catheter of claim 6, wherein, when the restrictor is deployed inside the blood vessel, the restrictor forms a plurality of flow paths.

    8. The catheter of claim 1, wherein, when the restrictor is deployed inside a blood vessel, fluid flows through the blood vessel via the flow path.

    9. The catheter of claim 1, wherein, when the restrictor is deployed inside a blood vessel, the flow path allows a predetermined amount of fluid to bypass the restrictor.

    10. The catheter of claim 1, wherein deployment of the restrictor inside a blood vessel creates a region of reduced pressure downstream of the restrictor.

    11. The catheter of claim 1, further comprising a pump connected to a distal end of the catheter body.

    12. The catheter of claim 11, wherein the pump comprises an impeller rotatably disposed within an impeller assembly.

    13. The catheter of claim 12, wherein the impeller assembly comprises an inlet and an outlet and, when the impeller is actuated, the impeller pumps fluid through the impeller assembly via the inlet and the outlet.

    14. The catheter of claim 11, wherein the pump is external to the catheter and is connected to the distal end of the catheter body via a lumen extending through the catheter.

    15. The catheter of claim 14, wherein actuation of the pump, when the catheter is inserted into a blood vessel, sucks fluid from the blood vessel to a reservoir outside the body.

    16. A method for treating edema, the method comprising: inserting a catheter comprising a restrictor into a blood vessel, the restrictor comprising a retracted configuration and a deployed configuration, and in the deployed configuration, an exterior surface of the restrictor is shaped to form at least one flow path along the exterior surface of the restrictor; and deploying the restrictor inside the blood vessel.

    17. The method of claim 16, wherein the restrictor is deployed upstream of a lymphatic duct to reduce pressure in the vicinity of the lymphatic duct and facilitating flow of lymph fluid from the duct and into the blood vessel, thereby alleviating symptoms associated with edema.

    18. The method of claim 16, wherein, when the restrictor is deployed inside the blood vessel, the flow path is formed between the exterior surface of the restrictor and a wall of the blood vessel.

    19. The method of claim 16, wherein deploying the restrictor inside the blood vessel restricts fluid flow to a predetermined amount of flow through the blood vessel via the flow path, thereby controlling cardiac preload.

    20. The method of claim 16, wherein, when the restrictor is in the deployed state, the exterior surface forms at least two inflection points defining a transition region from a convex to a concave surface.

    21. The method of claim 20, wherein the flow path is formed between the two inflection points, the two inflection points defining a convex surface that facilitates fluid flow.

    22. The method of claim 18, wherein deployment of the restrictor creates a plurality of flow paths.

    23. The method of claim 16, wherein the catheter further comprises a pump operably connected to a distal end of the catheter.

    24. The method of claim 23, further comprising activating the pump to pump fluid from the blood vessel.

    25. The method of claim 23, wherein the pump comprises an impeller housed within an impeller assembly that is connected to the distal end of the catheter.

    26. A catheter system comprising: a sheath; a catheter disposed within the sheath; and a restrictor mounted onto one of the sheath or the catheter, wherein the restrictor comprises a retracted and a deployed configuration, and in the deployed configuration, an exterior surface of the restrictor is shaped to form at least one flow path along the exterior surface of the restrictor.

    27. The catheter system of claim 26, wherein the flow path comprises at least two inflection points formed by the exterior surface of the restrictor.

    28. The catheter system of claim 26, wherein each of the inflection points defines a transition region from a convex to a concave surface.

    29. The catheter system of claim 26, wherein the at least one flow path is disposed between two inflection points that define a concave surface for promoting fluid flow.

    30. The catheter system of claim 26, wherein, when the restrictor is deployed inside a blood vessel, the flow path is formed between the exterior surface of the restrictor and a wall of the blood vessel.

    31. The catheter system of claim 30, wherein the restrictor comprises a plurality of flow paths.

    32. The catheter system of claim 26, wherein the restrictor is located on the sheath.

    33. The catheter system of claim 26, further comprising a second restrictor, the second restrictor mounted onto the catheter.

    34. The catheter system of claim 33, wherein the second restrictor does not comprise a fluid flow path.

    35. The catheter system of claim 26, wherein at least one of the catheter or the sheath comprises a pressure sensor.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0107] FIG. 1 shows a catheter according to some aspects of the invention.

    [0108] FIG. 2 shows a precision restrictor.

    [0109] FIG. 3 illustrates a catheter during a treatment.

    [0110] FIG. 4 shows a catheter system.

    [0111] FIG. 5 shows a sheath according to aspects of the invention.

    [0112] FIG. 6 is a cross-section of the sheath in a blood vessel.

    [0113] FIG. 7 shows a sheath with a restrictor.

    [0114] FIG. 8 shows an alternative embodiment of the flow path shown in FIG. 7.

    [0115] FIG. 9 shows a medical dilator.

    [0116] FIG. 10A shows a distal looking view of the catheter.

    [0117] FIG. 10B is a cross section.

    [0118] FIG. 11A illustrates a second approach for regulating blood flow with a restrictor.

    [0119] FIG. 11B is a cross section of the restrictor in the second approach.

    [0120] FIG. 12A illustrates another approach for regulating blood flow inside a blood vessel.

    [0121] FIG. 12B is a cross section.

    [0122] FIG. 13A illustrates a different approach for regulating fluid flow inside a blood vessel.

    [0123] FIG. 13B is a cross section.

    [0124] FIG. 14 illustrates one system of the disclosure.

    [0125] FIG. 15 shows another treatment system of the disclosure.

    [0126] FIG. 16 shows another treatment system of the disclosure.

    [0127] FIG. 17 shows the distal end of a flow restricting catheter.

    [0128] FIG. 18 shows the precision restrictor in the inflated state.

    DETAILED DESCRIPTION

    [0129] The invention provides a restrictor that provides for precision restriction. The restrictor provides for precision restriction on account of one or more flow paths along an exterior surface of the restrictor. The flow paths are of a defined construction, so that an amount of flow past the restrictor, in the deployed state, is completely predetermined and known by an operator. Because the restrictors of the invention include flow paths, vessel occlusion is not based on imprecisely guessing as to how much to expand the restrictor relative to the vessel wall. Rather, the restrictor can be fully deployed to the vessel wall and the flow paths determine the amount of fluid allowed to pass beyond the restrictor. Moreover, another advantage is that restrictors of the invention can adjust to the compliance of the vessel wall while still providing the same precise and predictable flow past the restrictor via the one or more flow paths in the restrictor. According, the restrictors of the present invention provide significantly more precise restriction than prior art standard occlusion balloons and are therefore, among other things, are better at controlling cardiac preload.

    [0130] The fluid dynamics of the precision resistors mean that they can be placed in a vessel for a long period of time without need for a controller or cyclic deflations and inflations. It will further be appreciated that the restrictor(s) control flow and they are relatively insensitive to fluctuations in the dimensions of the vein during the course of a procedure. In that manner, the invention encompasses the concept that restrictors can be placed at one or more locations in a patient's body to achieve different effects. Many examples are described in the summary above. Three general therapeutic embodiments include the following examples.

    [0131] In one embodiment, devices including a restrictor as described herein can be used for reduction in fluid returning to a right heart to thereby reduce right heart preload. A low-pressure region is defined as the region downstream of the restrictors and in fluid communication with the heart. Upstream of the restrictors is by definition the higher-pressure region. In patients where preload is elevated, this takes stress off the heart and improves performance. Since the left heart cannot pump more fluid than it gets from the right heart, improved right heart performance has a positive impact on cardiac output of the left heart.

    [0132] In another embodiment, if the boundaries of a low-pressure zone include the lymphatic outflow ducts then the invention will stimulate lymph flow. For example, a first precision restrictor placed in the inferior vena cava and a second restrictor also in the left internal jugular vein will define a low-pressure zone that includes the right heart, the superior vena cava, left innominate, left subclavian, the thoracic duct, all of the right innominate circulation and by implication the right lymphatic duct. Such an embodiment stimulates lymph flow.

    [0133] In another embodiment, if the low-pressure zone includes the venous circulation of an organ, then that organ can be targeted for benefit. For example, if the restrictor is placed in the inferior vena cava below the hepatic veins, then the liver circulation forms part of the low-pressure zone. In this embodiment, liver filtration is reduced, which has beneficial impacts on liver disorders. The skilled artisan can envision how such an approach could apply to additional organs.

    [0134] The invention also envisions the use of multiple precision restrictors to obtain beneficial effects. For example, a first precision restrictor can be placed to be operably associated with an organ (e.g., liver or kidney) and a second precision restrictor can be placed to be operably associated with the vascular bed proximate the heart. This second restriction can be placed at many different locations, such as the right innominate vein or the inferior vena cava. This approach provides benefits to both the heart as well as other organs. In such embodiment, a third precision restriction may optionally also be placed, such as in the internal jugular vein.

    [0135] Embodiments of precision restrictors are now described. The invention encompasses devices that include a single precision restrictor and embodiments that include multiple precision restrictors. For the use of multiple restrictors, the invention encompasses the use of a precision restrictor on a sheath plus one or more on a catheter. The invention also encompasses having two precision restrictors on a single catheter and having multiple catheters.

    [0136] FIG. 1 provides an exemplary embodiment of a device within the scope of the invention. As shown in FIG. 1, devices of the invention can include a restrictor with a flow path that allows some blood to flow around the restrictor, thereby alleviating buildup of pressure upstream of the restrictor that can otherwise cause the blood vessel to stretch, reducing the effectiveness of the restrictor and preventing the maintenance of a low-pressure zone. In particular, catheter systems of the invention may include an intravascular catheter that is implantable in a blood vessel to deploy a restrictor near a lymph duct. As discussed, deployment of the restrictor can create a region of reduced pressure that allows lymph to drain from the lymph duct and into circulation. The flow path allows a predetermined amount of blood flow to move around the restrictor so as to prevent excessive pressure buildup, which would otherwise cause the vessel to stretch.

    [0137] As shown in FIG. 1, the invention in certain embodiments may include a catheter 1001. The catheter 1001 includes a proximal portion 1041 and a distal portion 1043. The distal portion 1043 is dimensioned for insertion into a blood vessel (e.g., a jugular vein). A precision restrictor 1009 is mounted to the distal portion 1043 and is shown in the deployed configuration.

    [0138] The restrictor 1009 includes flow paths 1011, for allowing a predetermined amount of fluid to pass over an external surface of the restrictor 1009. The restrictor 1009 can include any number of flow paths 1011, for example, the restrictor 1009 can include one, two, three, four, five, six, or more flow paths 1011. The flow paths 1011 are of a defined architecture (discussed further in FIG. 2), so that an amount of flow past the deployed restrictor 1009 is completely predetermined and known by the operator. Inclusion of the flow paths 1011 provide several advantages over the prior art. For example, because the restrictors 1009 include flow paths, vessel occlusion is not based on imprecisely guessing as to how much to expand the restrictor relative to the vessel wall. Rather, the restrictor 1009 can be fully deployed to the vessel wall and the flow paths 1011 determine the amount of fluid allowed to pass beyond the restrictor. Moreover, the flow paths 1011 address issues of blood vessel compliances by allow some fluid to bypass the restrictor and thereby reduce likelihood of the blood vessel stretching during a treatment.

    [0139] In preferred embodiments, the catheter 1001 further includes at least one pressure sensor, and preferably at least two pressure sensors. The pressure sensors may be connected to a sensor lead 1013 disposed at the proximal end of the catheter 1001 for connecting to a controller, discussed below. The pressure sensors can be disposed upstream and downstream of the restrictor 1009. For example, in preferred embodiments, the catheter 1001 includes a proximal sensor 1056 and a distal sensor 1055. The sensors 1055, 1056 provide pressure measurements upstream and downstream of the restrictor, which can help establish and maintain a low-pressure zone in a preferred region of the circulatory system. For example, using the catheter 1001, the physician can establish and monitor a low-pressure zone upstream of an inflow tract of the patient's heart, such as, for example, in the inferior vena cava, which is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. By establishing a low-pressure zone upstream of the right atrium of the heart, fluid pressure on the heart is decreased, thereby helping the heart pump blood. During a treatment, if a measured pressure downstream of the restrictor 1009 elevates above a value of, for example, 8 mmHg, the physician may be alerted by, for example, an alarm connected to a control module operably associated with the sensor, to either re-position the catheter, adjust a size of the restrictor 1009.

    [0140] FIG. 2 shows a precision restrictor 209. The precision restrictor 209 is shown in a deployed configuration. In the deployed configuration, an exterior surface 202 of the restrictor 209 defines flow paths 211 between the exterior surface 202 and a blood vessel wall (not shown for clarity). In particular, the exterior surface 202 comprises inflection points 203, or inflection regions, that are formed by a shape of the exterior surface 202. The inflection points 203 are preferably neither concave or convex and instead define a transition region between a convex surface 205 and a concave surface 207. As illustrated, each fluid flow path 211 may be disposed between two inflection points 203 defining a concave surface 207. The fluid flow paths 211 are designed to allow only a predetermined amount of fluid to bypass the restrictor 209 when the restrictor 209 is the deployed inside the blood vessel.

    [0141] FIG. 3 illustrates a catheter 1001 during a treatment. During treatment, the catheter 1001 is inserted through a patient's skin 1117 and into a vein, such as a jugular vein 1121. The catheter 1001 can be advanced inside the vein 1121 by, for example, using an image guiding system, e.g., ultrasound imaging. Further, the catheter 1001 can be advanced down the jugular vein 1121 past a thoracic duct 1118 and into an innominate vein 1126. Once inside the innominate vein 1126 the restrictor 1009 may be deployed to partially occlude the vein and define one or more flow paths for allowing some blood to bypass the restrictor. It may alternatively be advanced further downstream to the superior vena cava (as shown). In this embodiment the precision restrictor 1009 now restricts flow from the vascular bed of both right and left innominate vascular beds. In FIG. 3 there are multiple flow paths across the restrictor 1009 (two are indicated by the arrows). In the deployed state, the restrictor 1009 establishes a region of low pressure downstream of the deployed restrictor to, for example, reduce workload on a patient's heart. According, a pressure at P2 is lower than a pressure at P1. Preferably, the catheter 1001 includes pressure sensors. For example, the catheter 1001 can include a proximal pressure sensor 1056 and a distal pressure sensor 1055. The proximal and distal pressure sensors 1056, 1055 provide pressure measurements upstream and downstream of the restrictor 1009 to monitor and maintain the low-pressure region downstream of the restrictor 1009.

    [0142] FIG. 4 shows a catheter system 1200. The catheter system 1200 includes a pressure control catheter 1201 with a flow restrictor 1209 and one or more pressure sensors, e.g., a distal pressure sensor 1255 and proximal pressure sensor 1256, for measuring pressures downstream and upstream, respectively, of the restrictor 1209. On a proximal portion of the pressure control catheter is a hub 1259 that, among other things, includes a connector 1213 for receiving data from the pressure sensors. The connector 1213 comprises a port for attaching a cable. Preferably, the cable is attachable to a mobile pressure monitoring cart 1221 comprising a computer linked to a graphic interface 1223 for displaying and interacting with data received by the one or more pressure sensors. Alternatively, the computer and graphics interface 1223 may be miniaturized and placed on the bed. The graphic interface may be touchscreen.

    [0143] In some embodiments, the pressure control catheter system 1200 can be used to regulate pressure inside the inferior vena cava 1215. For example, the pressure control catheter 1201 can be inserted into the inferior vena cava 1215 via the femoral vein 1216. Upon insertion into the inferior vena cava 1215 the catheter 1201 is operable to deploy a restrictor 1209 having at least one flow path. Upon deployment of the restrictor 1209, pressure downstream of the restrictor is reduced. Reducing pressure downstream of the restrictor inside the inferior vena cava reduces pressures on the heart, thereby allowing the heart to effectively eject blood.

    [0144] FIG. 5 shows a sheath 407 according to aspects of the invention. The sheath 407 includes a proximal portion 441 and a distal portion 443. The distal portion 443 is dimensioned for insertion into a vein or artery. The sheath 407 may comprise an elongated cylindrical body 447 that is substantially smooth across its surface with a precision restrictor 409 that is mounted near a distal tip 405. The body 447 may be comprise multiple parts that offer certain structural features. For example, the body 447 may comprise a jacket 449 disposed over a shaft 451 with a coil 453 disposed therein. The coil 453 can provide structural support around a circumference of the body 447 to prevent an interior lumen (e.g., a lumen for receiving a catheter) from collapsing after insertion into the blood vessel.

    [0145] The restrictor 409 preferably comprises a balloon designed to be inflated (corresponding to a deployed configuration) and deflated (corresponding to a relaxed configuration). In the inflated state, the restrictor at least partially occludes the blood vessel. Preferably, the restrictor is inflated in response to delivery of a fluid. Accordingly, the restrictor can be made from any one or more of a variety of materials configured to expand upon the delivery of a fluid thereto and to contract upon the withdrawal of the fluid. Exemplary materials from which the restrictor 409 can be made includes polymeric materials such as PEBAX, silicones, polyurethanes, and nylons.

    [0146] The device 407 includes an inflation lumen 455. The inflation lumen 455 is fluidically coupled with the first restrictor 409 to provide a mechanism for inflating the first restrictor 409 inside the blood vessel. The first restrictor 409 is inflatable via the inflation lumen 455 by delivering a fluid such as saline through the inflation lumen to the first restrictor 409. A pump may be used to facilitate the delivery of the fluid through the lumen 455 and into the first restrictor 409.

    [0147] In at least some embodiments, the distal tip 405 is a soft atraumatic tip that facilitates smooth, safe introduction of the sheath 407 into the vein. Exemplary materials from which the atraumatic tip can be made include polyurethanes.

    [0148] The proximal portion 441 of the sheath 407 is external to a patient's body during a treatment. The proximal portion 441 can include a number of features for navigating and securing the catheter system in place during the treatment. For example, the proximal portion may include a suture ring 457 to secure sheath 407 during catheter manipulation or during prolonged vascular access. Additionally, the proximal portion 441 may include multi-lumen tubing. The multi-lumen tubing may include the inflation lumen 455. The multi-lumen tubing may also include a lumen for one or more pressure sensors disposed on the sheath 407.

    [0149] FIG. 6 is a cross-section taken along line A-A of FIG. 5 when the sheath is disposed inside a blood vessel 520. This view highlights a flow path 511 defined between an exterior surface 516 of the restrictor 409 and a wall 521 of the blood vessel 520. The exterior surface 516 of the first restrictor 409 includes an inflection point 518 defining a change in curvature around a circumference of the first restrictor 409. The inflection point defines a transition between a convex surface 601 and a concave surface 603.

    [0150] FIG. 7 shows a sheath 701 with a restrictor 709. The restrictor 709 is illustrated in a deployed/inflated state and in the inflated state, the restrictor 709 forms a flow path 711. The sheath 701 also includes a distal portion 743 that is dimensioned for insertion into a blood vessel. The distal portion 743 can include a distal atraumatic tip 705 that has a soft material (e.g., polyurethane) in order to prevent damage to the blood vessel during insertion of the sheath.

    [0151] At a proximal portion 741 of the sheath 701, is a hub 759. The hub 759 may be designed to facilitate inflation of the restrictor 709. For example, the hub 759 may provide access to one or more inflation lumens that extend through the sheath 701 and connect to the restrictor 709. The restrictor 709 can be inflated by infusing a fluid into an inflation port 757 at the hub 759. The hub 759 may also provide access to a flush port 758. For example, a fluid, such as, a purge fluid may be delivered via the flush port which is external to the patient. The purge fluid can be used to purge or clear debris; for example, as described in co-owned U.S. Provision Application 62/629,914, which is incorporated by reference. The proximal portion 741 may also include a sensor lead 756, for receiving input from a sensor 754 disposed on the distal portion 743 of the sheath 701.

    [0152] FIG. 8 shows an alternative embodiment of the flow path 811 that is shown in FIG. 7. In particular, the flow path 811 is non-linear. A non-linear flow path 811 may be desired to resist the flow of fluid passing through the channel 811, helping maintain a reduced pressure downstream of the restrictor 809. The restrictor 809 is depicted in the retracted configuration. In some instances, the restrictor 809 may include an inlet and an outlet as an alternative, or in addition to, the flow path 811. The inlet and outlet may allow fluid to pass through an interior chamber of the restrictor 809.

    [0153] FIG. 9 shows a medical dilator 901. The medical dilator 901 is useful for dilating a blood vessel in preparation for a treatment. For example, the dilator may be used to dilate a blood vessel before advancing a catheter therein. The medical dilator 901 includes an elongated shaft that is preferably substantially cylindrical for passing through a cylindrical lumen of a sheath. The medical dilator includes a guide wire lumen 967 through which a guide wire can extend for moving the dilator within a blood vein or blood vessel. The medical dilator 901 further includes a distal tip 966, which may include features that prevent damage to the blood vessel, such as, an atraumatic tip comprising a soft material.

    [0154] In at least some embodiments, the restrictor(s) of a catheter can be inflated and deflated from time to time to enable free flow of blood in a patient's vein in which the restrictor(s) are positioned and thus enable the system to stop working for a period of time. This period of time can be required in such treatments to allow for the assessment of the patient's clinical condition, allow the patient to undergo other treatments or enable him to go to the bathroom and/or to wash any stagnation points that might have occurred.

    [0155] Furthermore, various systems and methods are provided for reducing pressure at an outflow of a duct such as the thoracic duct or the lymphatic duct. In general, the systems and methods may be effective to reduce edema conditions, such as pulmonary edema, in a patient by lowering an outflow pressure in a region around the patient's thoracic/lymphatic duct outflow. As a result of lowering the outflow pressure at the thoracic and/or lymphatic ducts, higher lymphatic return will be achieved, enabling the lymphatic vessel flow to be at or near normal levels. The systems and methods may be effective to rapidly alleviate conditions of the edema and increase the patient response rate. In an exemplary embodiment, the systems and methods may be particularly useful to treat acute pulmonary edema. However, a person skilled in the art will appreciate that the systems and methods can be used in various procedures for treating a lymphatic system fluid clearance imbalance.

    [0156] Systems and methods of the invention, according to some embodiments, rely on the insight that allowing some blood to flow past at least one of the fluid flow restrictor s is helpful for regulating pressures within a blood vessel. The invention considers a variety of approaches for achieving this benefit. Some of these approaches are further described in FIGS. 10-13.

    [0157] FIG. 10A and FIG. 10B illustrate an approach for regulating blood flow with a restrictor 2009 having flow paths 2011. Blood flows between the restrictor and the vessel wall.

    [0158] FIG. 10 A shows a portion of a catheter 2003 with a restrictor 2009 inside a blood vessel. Arrows indicate blood flow. As depicted, blood flows between the restrictor 2009 and a blood vessel wall 2013.

    [0159] FIG. 10B shows a cross section of the restrictor that is illustrated in the top panel. The flow paths are defined between the restrictor 2009, which is illustrated in an inflated state, and the blood vessel wall 2013. The flow paths may comprise holes that are approximately 0.3-1.0 millimeters in diameter.

    [0160] FIG. 11A shows a second approach for regulating blood flow with a restrictor 2109. In this approach, the restrictor 2109, illustrated in an expanded state, is sized such that a gap exists around at least a portion of a circumference of the restrictor 2109 and the blood vessel wall 2113. Blood flows between the restrictor and the vessel wall.

    [0161] FIG. 11B is a cross section of the restrictor 2109. When the catheter 2103 is inside the blood vessel, blood flows around the restrictor 2109 via the gap. The gap may be approximately 0.07 millimeters-016 millimeters.

    [0162] FIG. 12A and FIG. 12B illustrate another approach for regulating blood flow inside a blood vessel 2213.

    [0163] FIG. 12A illustrates a portion of a catheter 2203 with a restrictor 2209 inside a blood vessel 2213. Blood flows between the restrictor and the catheter/sheath. Disposed between the restrictor 2209 and the catheter 2203 is a fluid bypass tube 2211. Blood flows past the restrictor 2209 by flowing through the tube 2211. The tube 2211 can be sized so as to determine an amount of flow through the tube 2211. The tube 2211 may comprise a hole that is sized approximately 0.4-1.5 millimeters. Arrows indicate blood flow.

    [0164] FIG. 12B shows a cross section of the catheter 2203 illustrated in the top panel. The fluid bypass tube 2211 can comprise any size or shape. Preferably the restrictor comprises a torus shape.

    [0165] FIG. 13A illustrates a different approach for regulating fluid flow inside a blood vessel 2313. According to this embodiment, the restrictor 2309 may fully occlude the blood vessel 2309. Blood flows past the restrictor 2303 by traversing a lumen 2311 disposed within a shaft of the catheter 2303. Blood flows in catheter/sheath multilumen.

    [0166] FIG. 13B is a cross section of the restrictor 2309. In particular, blood flows into an inlet 2315 and out an outlet 2317 disposed on either side of the restrictor 2309, thereby circumventing the restrictor 2309. The lumen may comprise a diameter of approximately 1.0-1.5 millimeters.

    [0167] FIG. 14 illustrates a system 800 for treating patients with edema and/or acute decompensated heart failure. The system 800 is configured to facilitate a combination therapy wherein the first therapy comprises a venous therapy and the second therapy comprises an arterial therapy. In one embodiment the venous therapy of the combination therapy comprises supporting the return of blood and/or lymph to the right heart. In one embodiment the venous therapy of the combination therapy comprises one or more of: (i) reducing the outflow pressure in a large vein that drains blood from one or more visceral organs, (ii) reducing the outflow pressure at a lymphatic duct, (iii) reducing elevated right heart preload to within an optimal range. In one embodiment the arterial therapy of the combination therapy comprises supporting a weakened left heart in pumping arterial blood to at least one abdominal organ.

    [0168] In one embodiment the arterial therapy comprises an arterial catheter 812, said arterial catheter 812 configured to support improved blood perfusion to at least one visceral organ. The arterial catheter 812 comprises a catheter shaft 830, the catheter shaft 830 configured for advancement from an access site into the aorta 808, the catheter 812 comprising a plurality of lumens 831, a distal region 812d and a proximal region 812p wherein the distal region 812d comprises a pump assembly 817 and the proximal region 812p extends exterior of the patient. The proximal end of the arterial catheter 812p is connected to a console 813 to monitor the arterial therapy, control the arterial therapy and display arterial therapy information to the physician. The pump assembly 817 comprises an impeller 818 and a housing 819. The catheter 812 comprises a drive shaft 834 connected to the impeller 818 and configured to drive the impeller 818 to pump blood.

    [0169] In one variation, the pump assembly 817 comprises an expandable housing 819 and an expandable impeller 818. With this embodiment the larger diameter of the impeller 818 allows large volume of blood to be pumped at relatively lower revolutions per minute (RPM) of the impeller 818. In one embodiment the expandable housing 819 comprises a sealing element exterior of the housing 818 and the sealing element 825 apposes the wall of the artery 809. With this embodiment the sealing element 825 prevents blood flow in a retrograde direction outside the housing 819. The sealing element 825 may be configured to provide a bidirectional seal. With this embodiment the sealing element 825 applies a positive pressure to the vessel wall 809 and the energy source for the positive pressure is intrinsic to the assembly of the sealing element 825. In one embodiment the sealing element 825 is expandable. In one embodiment the sealing element 825 is inflatable. Alternatively, the sealing element 825 may be configured to facilitate flow in one direction, like a valve. A one directional sealing element allows blood to flow in an antegrade direction but not in a retrograde direction. With this type of sealing element 825 the pressure of sealing is at least partially extrinsic to the sealing element. In one variation the geometry of the sealing element is collapsed onto the housing 819 when upstream pressure is higher than the downstream pressure and the geometry of the sealing element is expanded against the vessel wall 809 when the downstream pressure is higher than the upstream pressure.

    [0170] The impeller assembly 817 of the system 800 comprises a blood flow inlet 838 and a blood flow outlet 839. The blood flow inlet 838 comprises at least one opening that facilitates the movement of blood into the housing 819 of the blood pump assembly 817. The blood flow outlet 839 comprises at least one opening that facilitates blood flow out of the housing 819 of the blood pump assembly 817. The blood flow inlet 838 is generally upstream of the impeller 818 and the blood flow outlet 839 is generally downstream of the impeller 818. In one embodiment the blood flow inlet 838 to the pump assembly 817 comprises at least one inlet strut 840. In one embodiment the blood flow outlet 839 from the pump assembly 817 comprises at least one outlet strut 841.

    [0171] In one embodiment the arterial catheter 812 comprises a first arterial pressure sensor 820e upstream of the pump assembly 817. The first arterial pressure sensor is configured to measure pressure upstream of the pump assembly 817. In one embodiment the first arterial pressure sensor is spaced apart from the pump assembly 817. In one embodiment the first arterial pressure sensor 820e is placed in the left ventricle of the patient. In one embodiment the first arterial pressure sensor is placed in the descending aorta of the patient. In one embodiment the catheter 812 comprises a second arterial pressure sensor 820f wherein said second arterial pressure sensor 820f is configured on the catheter for placement downstream of the pump assembly 817. The second arterial pressure sensor 820f is configured to measure the pressure of blood flowing to at least one visceral organ. The second arterial pressure sensor 820f is configured in one variation to be spaced apart from the pump. In one variation the second arterial pressure sensor 820f is configured on the catheter for placement in the abdominal aorta adjacent a renal artery. The first arterial pressure sensor 820e and the second arterial pressure sensor 820f comprise data transfer cables extending through a first arterial catheter lumen and second arterial catheter lumen respectively said data transfer cables configured for connection to the console 813 at the proximal end of the arterial catheter 812.

    [0172] In one embodiment the venous therapy comprises a first venous catheter 810, the first venous catheter comprising a proximal end 810p and a distal end 810d, the distal end 810d comprises a first blood flow restrictor 821a and the proximal end 810p extends exterior of the patient. The proximal end of the first venous catheter 810p is connected to a console 813 to monitor the therapy, control the therapy and display therapy information to the physician. The distal end of the first therapy catheter 810d comprises a first pressure sensor 820a, the first pressure sensor 820a positioned downstream of the first blood flow restrictor 821a to measure venous pressure between the first blood flow restrictor 821a and the right heart. The first blood flow restrictor 821a and the catheter 810 are configured for placing the first blood flow restrictor 821a in any one of: (i) the superior vena cava 801, (ii) the supra-hepatic inferior vena cava 803, (iii) the retro-hepatic inferior vena cava 804, (iv) the suprarenal inferior vena cava 805, (v) the infrarenal inferior vena cava 807, or (vi) a major branch vein of any of the above (including an innominate, internal jugular, subclavian or iliac vein). In one embodiment the first blood flow restrictor 821a is a precision restrictor as described in this patent. In one embodiment the first therapy catheter distal end 810d comprises a second pressure sensor 820b wherein the second pressure sensor 820b is proximal of the first blood flow restrictor 821a, the second pressure sensor 820b configured to measure blood pressure on the upstream side of the restrictor.

    [0173] In another embodiment the venous therapy comprises a third pressure sensor 820g, said third pressure sensor 820g mounted on an elongate member 826 said elongate member 826 configured for insertion into a peripheral vein, advancement through at least one central vein and a right heart chamber, crossing a pulmonary valve and placement in a pulmonary artery. The third pressure sensor 820g comprises a cable 827 said cable extending exterior of the patient and connected to a console 813 to display the pressure in a pulmonary artery to the doctor. In one embodiment the pressure measured by the third pressure sensor 820g is used to control at least one therapy parameter.

    [0174] In one variation of this embodiment the third pressure sensor 820g is mounted on said first venous catheter 810. With this variation the first venous catheter 810 comprises a distal extension 828, said distal extension 828 extending through at least one central vein, the right heart and across the pulmonary valve. The distal extension 828 of first venous catheter 810 carries the third pressure sensor into the pulmonary artery. In one embodiment the distal extension 828 is integral with the venous catheter 810. In another embodiment the distal extension 828 is moveable relative to the venous catheter 810. With this embodiment the venous catheter may comprise a lumen for the transit of the distal extension 828.

    [0175] In one embodiment the first venous catheter 810 comprises a multilumen catheter. With this embodiment the catheter 810 comprises a first lumen 829 configured for the inflation and deflation of the first blood flow restrictor 821a. The catheter comprises one or more pressure sensor lumen 830 (each) configured to hold a pressure sensor at a distal end 810d of each of the one of more pressure sensor lumens 830. The one or more pressure sensor lumen 830 comprises a pressure port 831 that brings the pressure sensor contained in the one or more pressure sensor lumen 830 into fluid connection to the venous fluid adjacent the one or more pressure sensors. In one embodiment the one or more pressure ports 831 comprise a skive in the wall of the shaft of the catheter 810. Preferably the one or more pressure sensors 820 is sealing mounted in the one or more pressure sensor lumens 830. With this embodiment fluid pressure is transmitted to the pressure sensor 820 without blood flowing farther down the lumen. Preferably the one or more pressure sensor lumens 830 comprises a proximal seal and a distal seal, the proximal seal proximal of at least a part of the sensing element 832 of the pressure sensor 830 and the distal seal distal of the one or more pressure ports 831.

    [0176] In one embodiment the venous therapy and the arterial therapy are operated at the same time. In one embodiment the venous therapy and the arterial therapy are operated at least partially in series. In one embodiment the venous therapy uses a first console 813a and the arterial therapy uses a second console 813b. In one embodiment the venous therapy and the arterial therapy use the same console.

    [0177] In one embodiment of the system 800, the console 813 comprises a controller 814, a user interface 815, and a cart 833. The controller 814 is configured to receive data from the at least one pressure sensor 820. The controller 814 is configured to compare the data from the at least one pressure sensor 820 to a stored value or to data from a second pressure sensor. The system 800 further comprises digital storage element 836 and a computer program 837. The computer program 837 comprises program code stored on a machine readable medium the computer program configured to execute on at least some of the methods associated with the use of the system 800. The system 800 comprises at least one output device 835 for outputting data measured by one or more system elements or stored data or calculated data. The system 800 further comprises an input apparatus 834 configured facilitate the inputting of data into the controller 814 or said digital storage element 836. The input apparatus 834 may comprise a touch screen display 816, a USB port, a keypad, or other standard data input devices known in the art. In one embodiment the program 837 comprises at least one decision criterion. The at least one decision criterion may result in an action wherein said action comprises one of the following (i) displaying charted or graphic information to the user, (ii) displaying a user alert, (iii) inflating the restrictor of the venous catheter, (iv) deflating the restrictor of the venous catheter, (v) increasing the impeller speed of the artery catheter, (vi) decreasing the speed of the impeller of the artery catheter, (vii) testing a bodily fluid or tissue sample. The at least one decision criterion may be calculated or determined by the controller 814 or any other item of the system 800 or a device interconnected to the system 800. The results of an evaluation, calculation, comparison data filtration or assessment performed by the controller 800 or device connected to it may be displayed on the monitor 816 or sent to an output device 835 or stored on a database.

    [0178] For the purposes of FIG. 14 and FIG. 15 the venous central region shall mean any region that includes two or more of (i) a lymphatic outflow, (ii) a renal vein and (iii) the right atrium. In one embodiment the venous therapy comprises reducing flow into the central region using a plurality of restrictors placed in large feeder veins peripheral to the central region. With this embodiment the venous therapy comprises a first restrictor 810 (as described above) and a second restrictor 811. The first restrictor 821a and second restrictor 821b are configured to restrict blood flow to the venous central region. The second restrictor 821b may be mounted on the first venous catheter 810. With this embodiment the first venous catheter 810 may extend across the venous central region with the first restrictor on one side of the central region and the second restrictor on the other side of the venous central region. For example, the first venous catheter 810 of this embodiment may access the venous system through a femoral vein and the first restrictor 821a may be placed in the infrarenal IVC, the catheter 810 may extend distally through the aorta, the SVC and the second restrictor mounted on the catheter 810 is configured for placement in the left innominate vein. It will be appreciated that the first venous catheter of this invention facilitates many configurations of said first restrictor 821a and second restrictor 821b. Table 1 below highlights 17 potential combinations grouped into categories and all of these combinations define slightly different central regions but each central region comprises at least two venous therapy targets

    TABLE-US-00001 Catheter configured so that first Catheter configured so that second restrictor 821a is placed in a restrictor 821b is placed in first target vein second target vein Infrarenal IVC or Iliac SVC, or Innominate, or Internal Jugular, or Subclavian. Suprarenal inferior vena cava or Innominate, or Internal Jugular, or retrohepatic inferior vena cava or Subclavian. suprahepatic inferior vena cava.

    [0179] In another embodiment the second restrictor 821b may be mounted on a second catheter 811 and delivered to a separate vein separate of the first venous catheter 810. With this embodiment the catheter 811 can have all of the features of the first venous catheter 810 as described above and is connected to the console 813 and operated by the console 813 in a likewise fashion. An example of this is depicted in FIG. 14 where the two catheters 810 and 811 are connected to the console 813 but inserted into two different veins. It will be appreciated that the first venous catheter and second venous catheter and their respective restrictors can equally be applied to the targets of Table 1 as the single catheter embodiment describes above.

    [0180] The system 800 of this invention facilitates a number of methods of use. In one embodiment the method comprises the steps of:

    [0181] Selecting a patient with reduced cardiac output and congestion,

    [0182] Inserting a distal segment of a cardiac support catheter 812 into the aorta of the patient,

    [0183] Actuating an impeller 818 in a distal region of the catheter 812 to pump blood and off load at least some of the pumping burden from the left ventricle,

    [0184] Inserting a distal segment of a venous catheter 810 into an access vein,

    [0185] Expanding a restrictor 821a associated with the catheter 810 in a vein adjacent to a central region, the restrictor 821a reducing the volume flow rate of blood returning to the central region and thereby improving the patients venous or lymphatic fluid dynamics,

    [0186] Operating the cardiac support catheter 812 and the venous catheter 810 with a console 813 to manage the treatment of the patient,

    [0187] Removing the venous catheter 810 and the cardiac support catheter 812 from the patient either together or at separate times.

    [0188] In one variation the selecting of a patient with fluid congestion and reduced cardiac output comprises selecting a patient with signs and symptoms of excess extracellular fluid. This includes selecting a patient with venous congestion, or interstitial congestion or both. In one variation the selecting of a patient with reduced cardiac output comprises selecting a patient with reduced left ventricular ejection fraction. This may include selecting a patient with poor blood circulation to the patient's peripheral regions (hands and feet).

    [0189] In one variation the inserting of a distal segment of a cardiac support catheter 812 into the aorta of the patient comprises placing the pump assembly 817 in the descending aorta between the aortic arch and the renal arteries. In one variation the inserting of a distal segment of a cardiac support catheter into the aorta of the patient comprises advancing the catheter until the blood pump inlet 838 to the pump assembly 817 is across the aortic valve and within the left ventricle of the patient's heart.

    [0190] In one variation the actuating of an impeller 818 in a distal region of the catheter 812 comprises rotating the impeller 818 at a speed of greater than 100 meters per minute. Preferably the actuating of the impeller 818 comprises rotating the impeller 818 at a speeds between 100 meters per minute and 600 meters per minute. With this embodiment the speed refers to the linear speed of the impeller 818 at its maximum diameter and can be calculated by multiplying the outer circumference of the impeller 818 by the number of revolutions per minute at which it operates.

    [0191] In another variation the inserting a distal segment of a venous catheter 810 into a vein comprises inserting the venous catheter 810 through a femoral vein, iliac vein, internal jugular vein or subclavian vein.

    [0192] The central region as described in the method above is a region of the central venous circulation that includes the right atrium and at least one and preferably more of (i) a renal vein or (ii) a lymphatic duct outflow. The central region may also include a hepatic vein. The central region may include two lymphatic duct outflows. The central region may include both renal veins.

    [0193] In a variation the expanding a restrictor 821 associated with the catheter 810 in a vein adjacent to a central region comprises expanding the restrictor 821 in a vein segment upstream of one or more of (i) the right atrium, (ii) a renal vein or (iii) a lymphatic duct outflow. In a variation the method comprises expanding a first restrictor 821a associated with the venous catheter 810 in a first vein segment adjacent to a central region and expanding a second restrictor 821b associated with the venous catheter 810 in a second vein adjacent to a central region. In another variation the method comprises expanding a first restrictor 821a associated with a first venous catheter 810 in a first vein segment adjacent to a central region and expanding a second restrictor 821b associated with a second venous catheter 811 in a second vein adjacent to a central region.

    [0194] In a variation the method comprises configuring the at least one restrictor 821 of the at least one venous catheter 810 to provide a defined level of restriction in a fully expanded state. With this variation on the method the restrictor 821 may configured to appose the vein wall yet still provide flow restriction. In one embodiment the method comprises providing a restrictor with at least one region of concavity in at least one fully expanded state.

    [0195] In one variation the improving the patients venous or lymphatic fluid dynamics comprises reducing the preload on the right heart thereby reducing the strain on the myocardium in the end diastolic phase. This variation of the method is configured to reduce pathologic right heart preload thereby improving right heart function and overall cardiac output. In another variation the improving the patients venous or lymphatic fluid dynamics comprises reducing the venous pressure in a renal vein. With this variation the method comprises an increased flow in the renal vein and thus better renal function and faster diuresis of excess extracellular fluid. In another variation the improving the patients venous or lymphatic fluid dynamics comprises reducing the pressure at a lymphatic duct outflow thereby stimulating lymph drainage and interstitial congestion. With this variation of the method, the stimulating of lymph drainage comprises protecting the kidneys from damage from a vascular volume depletion episode in a setting of high dose diuretics. The method of this variation further comprises reducing organ interstitial pressure and as a result improving organ function. For example, stimulating lymph drainage at the thoracic duct allows the cardiac tissue of the heart to off load excess interstitial fluid which drains to the thoracic duct and this in turn improves cardiac contractility. Similarly, lung function, liver function, intestinal function and kidney function will be improved by stimulating lymph drainage and reducing pathologic organ interstitial pressures.

    [0196] In a variation of the method operating the cardiac support catheter 812 and the venous catheter 810 with a console 813 comprises measuring one or more pressures in the aorta and/or left ventricle. The method may comprise the step of comparing the one or more pressure measurements from the aorta or left ventricle to a stored value or to a data measure from a second sensor 820(a,b,c,d,e,f). The method may comprise the step of displaying the results of an evaluation, calculation, comparison, data filtration or assessment on a monitor 816 for the physician. The method may comprise the step of increasing or decreasing the impeller speed in response to an evaluation, calculation, comparison, data filtration or assessment of a measured pressure.

    [0197] In a variation of the method operating the cardiac support catheter 812 and the venous catheter 810 with a console 814 comprises measuring one or more pressures in the central venous region. The method may comprise the step of measuring a pressure upstream of the restrictor 821. The method may comprise the step of comparing the pressure in the central region to a stored value or to a data measure from said measurement upstream of the restrictor 821. The method may comprise the step of activating a second restrictor 821 in response to a measurement taken from said central region pressure sensor 820a or said pressure sensor upstream 820b of the restrictor or both. The step of activating the second restrictor 821b may comprise activating said second restrictor 821b in a vein adjacent to but outside of the central region. The method may comprise the step of increasing the level of restriction to blood flowing to the central region. The method may comprise the step of decreasing the level of restriction to blood flowing to the central region. The method may comprise graduating the increasing or decreasing in the level of blood flow restriction proportionate to a measurement taken by a pressure sensor of at least one venous catheter or a calculation or comparison of said measurement.

    [0198] In another embodiment the method may comprise the step of measuring a parameter indicative of cardiac output, where said parameter may be ejection fraction, a pressure measurement in the heart or the aorta, a contractility measure, a biomarker measurement or other cardiac measurement. The method may comprise the step of measuring a parameter indicative of congestion status. Said measure of congestion status may comprise a central venous pressure, pulmonary artery wedge pressure, pulmonary artery pressure, an NT pro BNP measure, an interstitial pressure measure.

    [0199] In another embodiment the method comprises one or more of the steps of (i) providing a venous catheter configured for insertion into a vein, the venous catheter comprising a first restrictor configured for placement in a first vein and a second restrictor configured for placement in a second vein the first restrictor and second restrictor spaced apart on the catheter shaft, (ii) Inserting the venous catheter into the venous system via an internal jugular vein, (iii) Advancing the venous catheter through a first innominate vein, (iv) Navigating the venous catheter into a second innominate vein, (v) Advancing the venous catheter into a second internal jugular vein, (vi) Expanding a first and second restrictors in said first internal jugular vein and said second internal jugular vein, (vii) Providing a cardiac support catheter 812 the cardiac support catheter 812 comprising an impeller blood pump assembly 817, (viii) Advancing the cardiac support catheter 812 into the aorta of a patient, (ix) Operating the cardiac support catheter 812 to pump blood towards a renal artery, and/or (x) Operating the venous catheter to restrict blood flow towards the right atrium.

    [0200] In another embodiment the method comprises one or more of the steps of (i) providing a venous catheter 810 configured for insertion into a vein, the venous catheter 810 comprising a first restrictor 821a the first restrictor 821a comprising a precision restrictor (ii) Inserting the venous catheter 810 into the venous system via a peripheral access vein, (iii) Advancing the venous catheter 810 until the first restrictor 821a is in the infrarenal inferior vena cava 807, (iv) expanding the first restrictor 821a in the infrarenal inferior vena cava and restricting blood flow across the restrictor 821a, (v) Providing a cardiac support catheter 812 configured for insertion into an artery the cardiac support catheter 812 comprising an impeller blood pump assembly 817, (viii) Advancing the cardiac support catheter 812 into the aorta of a patient, (ix) Operating the cardiac catheter 812 to pump blood to reduce left ventricular end systolic pressure.

    [0201] In another embodiment the method comprises one or more of the steps of (i) providing one or more venous catheters configured for insertion into a vein, the one or more venous catheters comprising a first restrictor and a second restrictor said first and second restrictors comprising an activated state wherein the first and second restrictors restrict blood flow and a deactivated state wherein the first and second restrictors do not restrict blood flow, (ii) advancing the one or more venous catheters in one or more veins until the first restrictor is in a large supra-atrial vein (a vein above the right atrium) and the second restrictor is in an infra-atrial vein (a vein below the atrium), (iii) activating the first restrictor while the second restrictor is substantially deactivated, (iv) deactivating the first restrictor while substantially simultaneously activation the second restrictor.

    [0202] In one variation the method comprises a programmed activation of said first and said second restrictors. In another variation the method comprises activating and deactivating the first and second restrictors in response to measurements taken by sensors on the one or more catheters. In one embodiment the activation and deactivation of the first and second restrictors is coordinated in time. In one variation the activation of the supra-atrial restrictor is configured to reduce cardiac preload and the pressure in a renal vein. In one variation the activation of the infra-atrial restrictor is configured to reduce cardiac preload and the outflow pressure at the lymphatic ducts. In one variation the method comprises providing first and second restrictors that are precision restrictors. In one variation the step of advancing the first restrictor comprises placing the first restrictor in a super-atrial vein said vein comprising one of (i) the superior vena cava, (ii) an innominate vein or (iii) a jugular vein. In one variation the step of advancing the second restrictor comprises placing the second restrictor in an infra-atrial vein said vein selected from one of (i) the supra-hepatic inferior vena cava, (ii) the retro-hepatic inferior vena cava, (iii) the suprarenal inferior vena cava, (iv) the infrarenal inferior vena cava or (v) an iliac vein.

    [0203] FIG. 15 illustrates a system 900 for treating patients with edema or heart failure or edema in a heart failure patient. The system 900 is configured to facilitate a combination therapy wherein the first therapy comprises a venous therapy and the second therapy comprises an arterial therapy. In one embodiment the venous therapy of the combination therapy comprises reducing elevated right heart preload to within an optimal range. In one embodiment the arterial therapy of the combination therapy comprises supporting the cardiac output of a weakened left heart by pumping arterial blood to at least one abdominal organ. In one embodiment both venous and arterial therapies function to improve cardiac output. The venous therapy improves cardiac output by reducing right atrial preload to within a normal range and the arterial therapy improves cardiac output by improving ventricular performance. In one embodiment the arterial therapy comprises an arterial catheter 912, said arterial catheter 912 configured to support the left ventricle in improving cardiac output. The arterial catheter 912 comprises a catheter shaft 930, the catheter shaft 930 configured for advancement from an access site into the aorta 808, the catheter 912 comprising a plurality of lumens 931, a distal region 912d and a proximal region 912p wherein the distal region 912d comprises an impeller pump 917 and the proximal region 912p extends exterior of the patient. The proximal end of the arterial catheter 912p is connected to a console 813 to monitor the arterial therapy, control the arterial therapy and display arterial therapy information to the physician. The pump assembly 917 comprises an impeller 918 (hidden) and a housing 919. The catheter 912 comprises a drive shaft 934 connected to the impeller 918 and configured to drive the impeller 918 to pump blood. In one variation, the pump assembly 917 comprises an expandable housing 919 and an expandable impeller 918. With this embodiment the larger diameter of the impeller 918 allows a large volume of blood to be pumped at relatively lower revolutions per minute (RPM) of the impeller 918. The impeller assembly 917 of the system 900 comprises a blood flow inlet 938 and a blood flow outlet 939. The blood flow inlet 938 comprises at least one opening that facilitates the movement of blood into the housing 919 of the blood pump assembly 917. The blood flow outlet 939 comprises at least one opening that facilitates blood flow out of the housing 919 of the blood pump assembly 917. The blood flow inlet 938 is generally upstream of the impeller 918 and the blood flow outlet 939 is generally downstream of the impeller 918. In one embodiment the blood flow inlet 938 to the pump assembly 917 comprises at least one inlet strut 940. In one embodiment the blood flow outlet 939 from the pump assembly 917 comprises at least one outlet strut 941. The left ventricular orientation of the inlet 938 will vary throughout the cardiac cycle as a result of the pumping heart. This movement can cause the inlet to be positioned next to cardiac structures that have the potential to occlude or partially occlude the inlet 938 leading to loss of performance or the development of adhesion between the vascular therapy device and surrounding cardiac structures as a result of suction developing between the vascular therapy device and surrounding cardiac structures. In another embodiment a balloon 950 is incorporated adjacent to the inlet 938 functioning to maintain a minimum distance from cardiac structures thereby preventing suction events at the pump inlet 938. In this embodiment the balloon 950 is inflated and deflated through one of the plurality of lumens 931 within the catheter shaft 930. A pre-shaped polymeric tip or polymeric tip combined with a shape memory material such as Nitinol may also be utilized to achieve the same function of preventing adhesions or inlet flow restriction or suction events. In one embodiment the housing 919 and impeller 918 comprise an expandable housing and expandable impeller and are located in the ascending aorta or aortic arch with a part of the expandable housing 919 or an extension to the expandable housing 919 extending into the left ventricle. In this embodiment the inlet 938 comprises the distal end of the expandable member and the outlet 939 is positioned adjacent to the impeller 918. With this embodiment blood is pumped from the ventricle to the aorta thereby increasing cardiac output. The inlet 938 may be predominantly axially aligned relative to the catheter shaft or constitute a radial terminus to the expandable housing 919. In another embodiment the expandable housing 919 and expandable impeller 918 are located in the left ventricle with the expandable housing extending proximally through the aortic valve to the ascending aorta or aortic arch. In this arrangement, blood is also being pumped from the ventricle to the aorta thereby increasing cardiac output. Non expandable impellers 918 and/or housings 919 may be used in both of the aforementioned embodiments. In one embodiment the arterial catheter 912 comprises a first arterial pressure sensor 920c upstream of the inlet 938 and is configured to measure pressure upstream of the pump assembly 917 in the left ventricle. In one embodiment the first arterial pressure sensor is spaced apart from the pump assembly 917. In one embodiment the first arterial pressure sensor 920c is placed in the left ventricle of the patient. In one embodiment a second arterial pressure sensor is placed in the descending aorta of the patient 920d. In one embodiment the catheter 812 comprises a second arterial pressure sensor 920d wherein said second arterial pressure sensor 920d is configured on the catheter 912 for placement downstream of the pump assembly 917. In one embodiment the second arterial pressure sensor 920d (or a third arterial pressure sensor 920e) is configured to measure the pressure of blood flowing to at least one visceral organ. The second arterial pressure sensor 920d is configured in one variation to be spaced apart from the pump 917. In one variation the second arterial pressure sensor 920d is configured on the catheter for placement in the abdominal aorta adjacent a renal artery. The first arterial pressure sensor 920c and the second arterial pressure sensor 920d comprise data transfer cables extending through an arterial catheter first lumen and arterial catheter second lumen respectively said data transfer cables configured for connection to the console 813 at the proximal end of the arterial catheter 912. It will be appreciated that the functions, features, and method of use of the venous catheters and arterial catheters described with regard to FIG. 14 can be replicated in whole or in part of the embodiment shown in FIG. 15. It will also be appreciated by those with knowledge in the art that the devices herein described require the implementation of miniaturized and precision engineered componentry manufactured to micrometer level accuracy.

    [0204] In one embodiment the method comprises one or more of the steps of (i) providing a venous catheter 910 configured for insertion into a vein, the venous catheter 910 comprising a first restrictor 921a and at least one pressure sensor the first restrictor 921a comprising a precision restrictor (ii) Inserting the venous catheter 910 into the venous system via a peripheral access vein, (iii) Advancing the venous catheter 910 until the first restrictor 921a is in the superior vena cava vein 801, (iv) expanding the first restrictor 921a in the superior vena cava 801 and restricting blood flow across the restrictor 921a, (v) operating the venous catheter 910 to maintain right atrial pressure within a targeted range, (vi) Providing an arterial cardiac support catheter 912 configured for insertion into an artery the cardiac support catheter 912 comprising an impeller blood pump assembly 917 and at least one pressure sensor, (vii) Advancing the cardiac support catheter 912 into the ventricle of a patient, (viii) Operating the cardiac catheter 912 to pump blood towards at least one visceral organ, (ix) providing a console and synchronously operating said venous catheter and said arterial catheters with the console to enhance overall cardiac output.

    [0205] FIG. 16 shows a system 1000 for treating patients with edema or acute decompensated heart failure or acute decompensated heart failure with edema. The system 1000 is configured to facilitate a combination therapy wherein the first therapy comprises a venous therapy delivered in a major supra-atrial vein and the second therapy comprises a venous therapy delivered in a major infra atrial vein. In one embodiment the major supra-atrial vein comprises the superior vena cava 801. In one embodiment the major supra-atrial vein comprises an innominate vein. In one embodiment the major infra-atrial vein comprises the one of the following positions: i) the infrarenal inferior vena cava 807, ii) the suprarenal inferior vena cava (805), iii) the retrohepatic inferior vena cava (804), or iv) the suprahepatic inferior vena cava (803). In one embodiment the combination therapy comprises reducing elevated right heart preload to within an optimal range by restricting both the superior vena cava 801 and infrarenal inferior vena cava 807 flow simultaneously or in a sequence based on measurement and interpretation of hemodynamic parameters to achieve said optimal range.

    [0206] In one embodiment the first venous therapy comprises a first venous catheter 1010, the first venous catheter comprising a proximal end 1010p and a distal end 1010d, the distal end 1010d comprises a first blood flow restrictor 1021 and the proximal end 1010p extends exterior of the patient. The proximal end of the first venous catheter 1010p is connected to a console 1013 to monitor the therapy, control the therapy and display therapy information to the physician on the display/user interface 1016 of the console. The distal end of the first therapy catheter 1010d comprises a first pressure sensor 1020a, the first pressure sensor 1020a positioned downstream of the first blood flow restrictor 1021a to measure venous pressure between the first blood flow restrictor 1021a and the right heart. The first therapy catheter 1010 further comprises a second pressure sensor 1020b upstream of the first therapy catheter restrictor 1021. The first pressure sensor 1020a and second pressure sensor 1020b can be used to measure the pressure gradient across the restrictor and the console 1013 comprises a body of software configured increase or decrease the level of restriction or to direct the physician to change the level of restriction manually. In the same embodiment a second venous therapy comprises a second venous catheter 1012, the second venous catheter comprising a proximal end 1012p and a distal end 1012d, the distal end 1012d comprises a second blood flow restrictor 1022 and the proximal end 1012p extends exterior of the patient. The proximal end of the second venous catheter 1012p is connected to a console 1013 to monitor the therapy, control the therapy and display therapy information to the physician on the user interface/display 1016. The distal end of the second therapy catheter 1012d comprises a third pressure sensor 1020c, the third pressure sensor 1020c positioned downstream of the second blood flow restrictor 1022 to measure venous pressure between the second blood flow restrictor 1022 and the right heart. The second therapy catheter 1012 further comprises a fourth pressure sensor 1020d upstream of the second therapy catheter restrictor 1022. The third pressure sensor 1020c and fourth pressure sensor 1020d can be used to measure the pressure gradient across the restrictor 1022. In one embodiment the console 1013 comprises a body of software configured to analyze or process data received from said first, second, third and fourth pressure sensors. In one embodiment the system is configured to increase or decrease the level of restriction of the first blood flow restrictor 1021 and/or the second blood flow restrictor 1022. In a preferred variation the increase or decrease in restriction comprise an increase or decrease in the inflated volume or pressure of the first and/or second precision restrictors.

    [0207] In one embodiment the method of the combination therapy comprises expanding the first precision restrictor 1021 to reduce right atrial pressure and the venous outflow pressure of at least one visceral organ. In one embodiment the method comprises collapsing the first precision restrictor 1021 to reduce the outflow pressure of at least one lymphatic duct. In one embodiment the method comprises expanding the first precision restrictor 1021 for a first time period and then collapsing the first precision restrictor 1021 for a second time period so as to sequentially reduce right atrial pressure and the venous outflow pressure of at least one visceral organ in the first time period and then to reduce the outflow pressure of at least one lymphatic duct outflow in the second time period. It will be appreciated that the first time period and second time period may be equal in length or the first time period may be longer than the second or the second time period may be longer than the first time period. It will also be appreciated that repeating the pattern of inflating and deflating the precision restrictor 1021 allows the doctor to target cardiac, lymphatic and visceral organ therapy targets in a single procedure.

    [0208] In one embodiment the method of the combination therapy comprises expanding the second precision restrictor 1022 in a region of the inferior vena cava (as outlined above) to reduce the right atrial pressure and the pressure at an outflow of at least one lymphatic duct. In one embodiment the method comprises collapsing the second precision restrictor 1022 in a region of the inferior vena cava. The depressurizing of the second restrictor in the inferior vena cava may achieve one or more of the following depending on the location in the IVC (i) reduce the (outflow) pressure in a major vein of at least one visceral organ, (ii) allow the drainage of fluid from the peripheral venous circulation. As with the first precision restrictor it will be appreciated that the second precision restrictor may be inflated for a third time period and then deflated for a fourth time period and that this pattern may be repeated so as to create a continuous pattern of inflation and deflation.

    [0209] It will further be appreciated that the inflation/deflation patterns of the first precision restrictor and the second precision restrictor may be coordinated such that drainage and filling needs of the circulation are being optimized even though the patient has an excess of blood volume (held primarily in the venous compartment). In one embodiment the pattern comprises the first restrictor being inflated while the second restrictor is deflated. In one embodiment the pattern comprises the first restrictor being deflated while the second restrictor is inflated. In one embodiment the pattern comprises the first restrictor and the second restrictor being simultaneously inflated or deflated for a part of the pattern.

    [0210] In one embodiment the method comprises placing the second restrictor in the supra-hepatic inferior vena cava 803, the retro-hepatic inferior vena cava 804, the suprarenal inferior vena cava 805 or the infrarenal inferior vena 807. In one preferred embodiment the method comprises placing the first precision restrictor in the superior vena cava and placing the second precision restrictor 1022 in the infrarenal inferior vena cava and simultaneously operating both restrictors to a defined inflation and deflation pattern while in these locations. In another preferred embodiment the method comprises placing the first precision restrictor in the superior vena cava and placing the second precision restrictor 1022 in the supra-hepatic inferior vena cava and simultaneously operating both restrictors to a defined inflation and deflation pattern while in these locations. It will be appreciated that in a variation of the system and the method that the first and second precision restrictors may be configured on a single venous catheter and this catheter may be advanced from a single access vessel (ex internal jugular vein, or subclavian vein or femoral vein) and the steps and variations of the method conducted accordingly.

    [0211] It will be further appreciated that inflating and deflating the first precision restrictor 1021 and second precision restrictor 1022 in a coordinated pattern allows the doctor to target cardiac, lymphatic and visceral organ therapy targets to great effect in a single procedure. An important feature of this combined therapy is that the precision restrictors, even when fully inflated, never completely occlude flow, and so a limited degree of venous drainage is provided for every tissue and organ at all times during therapy.

    [0212] FIG. 17 shows the distal end of a flow restricting catheter 1170 including the catheter shaft 1171, with an inflation lumen 1172 extending therethrough, pressure sensors 1173a and 1173b disposed either side of the precision restrictor 1175 shown in the collapsed state. The flow restricting catheter 1170 further comprises an atraumatic tip 1176.

    [0213] FIG. 18 shows the precision restrictor 1175a in the inflated state. In this embodiment the precision restrictor comprises two flow paths 1181 disposed diametrically opposite each other. The flow paths 1181 comprise regions of concavity 1182 extending the length of the precision restrictor 1175a. It will be appreciated that when this restrictor balloon is inflated in a vein that the restrictor will induce a shape change in the vein that is non-circular. The vein will conform to the curve of the convex regions but will take the shortest path across the concave region. In this case the vein will assume a shape of a rounded rectangle when expanded. It will be appreciated that a variety of shapes are possible depending on the number of regions of concavity on a precision restrictor. Preferably there are just two flow paths and thus two regions of concavity.

    [0214] The catheter is dimensioned such that a distal portion of the catheter is insertable into a proximal portion of the sheath. Upon insertion, the distal portion of the catheter extends from the distal end of the sheath such that the second restrictor, which is mounted to the catheter, is distal to the first restrictor mounted on the sheath. Advantageously, because the first restrictor is introduced into the body via the sheath, and does not need to pass through a component of the catheter system, e.g., a tube, the first restrictor is less likely to tear or acquire abrasions caused by friction due to rubbing against a component of the catheter system. Accordingly, catheter systems of the present invention are less prone to breaking during treatment.

    [0215] The catheter can be made to be slidable within the sheath. Because the catheter is slidable within the sheath, a distance between the first restrictor and the second restrictor is adjustable by moving the catheter longitudinally (indicated by the double arrows) relative to the sheath. Advantageously, this allows the restrictors to be placed at precise locations within the body. For example, the restrictors can be placed at precise locations on either side of a lymph duct to define an exact low-pressure zone for withdrawing lymph fluid. Because the low-pressure zone can be exactly defined, the low-pressure zone can be made small, thereby reducing the amount of work that a pump must do to further reduce pressure within the zone and withdraw fluid therefrom. Additionally, because the restrictors are separately movable, the restrictors can be placed at various locations within the body depending on the type of treatment to be performed. Accordingly, the utility of catheters of the invention are improved.

    [0216] In some embodiments, a first restrictor and a second restrictor can be positioned at desired locations within one or more blood vessels. The first and second restrictor can be positioned at desired locations by moving (e.g., sliding) the sheath comprising the first restrictor into the blood vessel and guiding the sheath within the blood vessel until the first restrictor is in the desired location, for example, immediately upstream of a lymph duct. The catheter comprising the second restrictor may be advanced through the sheath by sliding the catheter through a lumen of the sheath. The second restrictor can be placed in a desired location by sliding the catheter relative and through the sheath inside the vein. The first and second restrictors can then each be activated (simultaneously or sequentially) to transition from the relaxed configuration to the activated configuration. The first and the second restrictors when activated provide two occlusions within the vein.

    [0217] Certain aspects of the invention employ a pump to withdraw fluid from a target zone (established between a first and second restrictor) to reduce pressure and withdraw fluid. One insight of the invention is that the right ventricle of the heart may be used as the pump for withdrawing fluid. For example, if the right ventricle is connected to a target zone then it will reduce pressure in that zone. However, in some patients the heart is weak and too much flow is coming to the heart (the entire venous system). Therefore, it may not be possible to get the desired reduction in pressure. However, if the size of the target region is reduced (i.e., moving the restrictors) then the right heart can deal with the reduced volume and pressure would come down.

    [0218] In alternative embodiments, multiple catheters, each with a separate restrictor can be used for multi-restrictor placement.

    [0219] It is envisioned that precision restrictors may be incorporated into other devices, such as those described for example in U.S. patent application publication number 2020/0268951, U.S. Pat. Nos. 9,901,722, 10,149,684, U.S. patent application publication number 2018/0126130, U.S. patent application publication number 2018/0250456, U.S. Pat. No. 9,393,384, U.S. patent application publication number 2017/0049946, U.S. patent application publication number 2018/0243541, and U.S. patent application publication number 2019/0126014, the content of each of which is incorporated by reference herein in its entirety.

    INCORPORATION BY REFERENCE

    [0220] References and citations to other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been made throughout this disclosure. All such documents are hereby incorporated herein by reference in their entirety for all purposes.

    EQUIVALENTS

    [0221] Various modifications of the invention and many further embodiments thereof, in addition to those shown and described herein, will become apparent to those skilled in the art from the full contents of this document, including references to the scientific and patent literature cited herein. The subject matter herein contains important information, exemplification and guidance that can be adapted to the practice of this invention in its various embodiments and equivalents thereof.