Thoracic duct seal for pumps for the alleviation of lymphatic congestion

Abstract

An implantable thoracic duct pump device and method for alleviating diuretic-refractory fluid overload. In an embodiment, the implantable thoracic duct pump device includes a fluid micropump with a motor inlet and a motor outlet; a thoracic duct cannula in fluid communication with the motor inlet; and a duct seal surrounding an exterior of the thoracic duct cannula and configured to form a seal at an outlet of a thoracic duct, wherein the duct seal is sized and shaped to seal an ostium of the thoracic duct when the thoracic duct cannula of the implantable thoracic duct pump device is implanted in the thoracic duct of a subject. In an embodiment, the method includes providing an implantable thoracic duct pump device external to the thoracic duct outlet within a venous system of a subject, and generating a pressure differential between the venous system and the thoracic duct of the subject.

Description

THORACIC DUCT SEAL FOR PUMPS FOR THE ALLEVIATION OF LYMPHATIC CONGESTION CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application 63 / 677,074 filed July 30, 2024, the entire disclosure of which is hereby incorporated by reference. BACKGROUND

[0002] Reducing pressure in the lymphatic duct system can be beneficial for heart failure by alleviating fluid congestion, a common issue in this condition. In heart failure, the heart's reduced function leads to fluid accumulation in tissues, resulting in edema and increased pressure in the lymphatic system. Consistently elevated central venous pressure results in high lymphatic pressure and worsened volume retention and can be a driver of chronic inflammation. The outlet of the thoracic duct, located at the junction of the left subclavian vein and the internal jugular vein, allows lymph to enter the venous system, completing the lymphatic drainage from the body. By lowering the pressure in the lymphatic duct, the fluid drainage from tissues improves, reducing edema and relieving strain on the cardiovascular system. This can enhance overall circulation, decrease symptoms such as swelling and breathlessness, and potentially improve the quality of life for individuals with heart failure. Effective lymphatic drainage also supports better organ function and can contribute to reducing the overall burden on the heart, and this is likely an advantageous approach in treating patients with diuretic refractory volume overload.

[0003] Under normal conditions, a normal volume of oxygen-rich blood is pumped to the body from the left ventricle. Following heart failure, there is a reduced volume of oxygen-rich blood pumped to the body from a ventricle. Congestive heart failure can result in an enlarged heart, heart congestion, excess fluid around the lungs, shortness of breath, swelling in the legs and feet, and edema. Following congestive heart failure there can be increased fluid accumulation in tissues and the lymphatic system. This increase in production and flow from the lymph system can lead to increased resistance from the thoracic duct into the venous system which is exacerbated when combined with the increased central venous pressure typically found in heart failure. 3915-P1359WO.UW -1-

[0004] Current work in this field is limited. One past approach to improving this problem has included an intravenous pump system that can help improve lymphatic flow in the critical care setting without directly cannulating the thoracic duct. However, this does not address the largest need in the field of outpatient volume management. Another approach has put together a design concept for a surgically implanted pump that can connect to the side of the thoracic duct as a way to reduce lymphatic pressure, but the concept would require a large wearable battery and would be an electrically inefficient design with likely low market adoption. Neither of these rely on an efficient seal created between the lymphatic and venous systems that allows the pump to efficiently create a pressure differential to enhance the forward flow of lymph and reduce the pressure within the lymphatic system.

[0005] What is needed is an effective anatomically-designed fluid barrier between the lymphatic and venous systems such that a pump can reduce lymphatic pressure, that is adaptable to the ambulatory setting, that can be easily implanted either in either catheter-based or surgical methods and can be easily used by patients. SUMMARY

[0006] To address these and related challenges, the present disclosure provides devices and methods capable of alleviating diuretic refractory fluid overload.

[0007] In an aspect, the present disclosure provides an implantable thoracic duct pump device including: a fluid micropump including a motor inlet and a motor outlet; a thoracic duct cannula in fluid communication with the motor inlet; and a duct seal surrounding an exterior of the thoracic duct cannula and configured to form a seal at an outlet of a thoracic duct, wherein the duct seal is sized and shaped to seal an ostium of the thoracic duct when the thoracic duct cannula of the implantable thoracic duct pump device is implanted in the thoracic duct of a subject.

[0008] In some embodiments, the implantable thoracic duct pump device further includes a duct-cannula retainer.

[0009] In some embodiments, the duct-cannula retainer includes a sealing balloon.

[0010] In some embodiments, the implantable thoracic duct pump device further includes a sleeve positioned on an exterior of the duct-cannula retainer configured to retain the duct-cannula retainer in a stationary configuration within the thoracic duct. In some 3915-P1359WO.UW -2-embodiments, the sleeve includes a sleeve texture configured to provide friction with an internal lumen of the thoracic duct.

[0011] In some embodiments, the duct seal includes a contoured sealing ring. In some embodiments the duct seal includes a flange that lays along the vein wall immediately adjacent to the thoracic duct ostium, such that it can facilitate pressure reduction of the lymphatic system beginning immediately at the terminal thoracic duct ostium without blocking lymphatic channels that connect towards the end of the terminal thoracic duct.

[0012] In some embodiments, the implantable thoracic duct pump device further includes a lumen adjacent to the contoured sealing ring, wherein the lumen is sized and shaped to promote lymphatic flow from small lymphatic vessels that fluidly connect to a terminal end of the thoracic duct through the implantable thoracic duct pump device.

[0013] In some embodiments, the implantable thoracic duct pump device further includes a power supply cable connected to the fluid micropump, wherein the power supply cable is in electrical communication with a power source. In some embodiments, the power source is a battery sized and shaped for subcutaneous implantation.

[0014] In some embodiments, the duct seal includes two or more tack points configured to be embedded in a vein of the subject.

[0015] In some embodiments, the duct seal includes two or more external braces including a first brace side and a second brace side, wherein the first brace side is coupled to the duct seal, and wherein the second brace side is configured to contact a portion of a vein of the subject.

[0016] In some embodiments, the thoracic duct cannula includes a first inlet and a second inlet. In some embodiments, the first inlet is at a distal end of the thoracic duct cannula. In some embodiments, the second inlet is defined along a wall of the thoracic duct cannula. In some embodiments, the second inlet includes a plurality of perforations in the wall of the thoracic duct cannula configured to allow lymphatics from both the thoracic duct and from lymphatic side channels of the thoracic duct to enter the thoracic duct cannula.

[0017] In an aspect, the present disclosure relates to a method of alleviating diuretic refractory fluid overload, the method including: providing an implantable thoracic duct pump device external to the thoracic duct outlet within a venous system of a subject, wherein the implantable thoracic duct pump includes: a fluid micropump including a motor inlet and a motor outlet wherein the motor outlet is located at a junction of a left subclavian 3915-P1359WO.UW -3-vein and an internal jugular vein of the venous system of the subject; a thoracic duct cannula in fluid communication with the motor inlet; and a duct seal surrounding an exterior of the thoracic duct cannula and configured to form a seal in a thoracic duct, wherein the duct seal is sized and shaped to seal the ostium at an outlet of the thoracic duct when the implantable thoracic duct pump device is implanted in the thoracic duct of a subject; and generating a pressure differential between the venous system and the thoracic duct of the subject, thereby facilitating lymphatic flow into the venous system.

[0018] In some embodiments, the implantable thoracic duct pump device further includes a duct-cannula retainer.

[0019] In some embodiments, the implantable thoracic duct pump device further includes a sleeve positioned on an exterior of the duct-cannula retainer and configured to retain the duct-cannula retainer in a stationary configuration within the thoracic duct. In some embodiments, the duct-cannula retainer includes a sealing balloon. In some embodiments, the duct-cannula retainer includes a porous positioning device sized and shaped to prevent the thoracic duct cannula from contacting a wall of the thoracic duct.

[0020] In some embodiments, the duct seal includes a contoured sealing ring configured to seal an ostium of the thoracic duct. In some embodiments, the duct seal includes a flange that is sized and shaped to lay along a vein wall immediately adjacent to the thoracic duct ostium, such that it can facilitate pressure reduction of the lymphatic system beginning immediately at the terminal thoracic duct ostium without blocking lymphatic channels that connect towards the end of the terminal thoracic duct.

[0021] In some embodiments, the implantable thoracic duct pump device further includes a lumen adjacent to the contoured sealing ring, wherein the lumen is sized and shaped to promote lymphatic flow from small lymphatic vessels that fluidly connect to the terminal thoracic duct.

[0022] In some embodiments, the method further includes the step of supplying electric power to the fluid micropump via a power supply cable in the venous system, wherein the power supply cable is in electrical communication with a power source.

[0023] In some embodiments, the power source is a battery sized and shaped for subcutaneous implantation.

[0024] In some embodiments, the duct seal includes two or more tack points configured to be embedded in a vein of a subject. 3915-P1359WO.UW -4-

[0025] In some embodiments, the duct seal includes two or more external braces including a first brace side and a second brace side, wherein the first brace side is coupled to the duct seal, and wherein the second brace side is configured to contact a portion of a vein of a subject.

[0026] In some embodiments, the thoracic duct cannula includes a first inlet and a second inlet.

[0027] In some embodiments, the first inlet is at a distal end of the thoracic duct cannula.

[0028] In some embodiments, the second inlet is defined along a wall of the thoracic duct cannula.

[0029] In some embodiments, the second inlet includes a plurality of lumens in the wall of the thoracic duct cannula configured to draw lymphatics from both the thoracic duct and from lymphatic side channels of the thoracic duct.

[0030] In an aspect, the present disclosure relates to a method of implanting an implantable thoracic duct pump device, the method including: accessing a left thoracic duct via a percutaneous transcervical approach; accessing a right subclavian vein via micropuncture access; inserting a first guide wire and a guide catheter into the right subclavian vein; inserting a second guide wire into the right subclavian vein via the left thoracic duct; inserting a catheter over the second guide wire; inserting a snare into a brachiocephalic vein; snaring the second guide wire with the snare; drawing the second guide wire out through the right subclavian vein by pulling on the snare; inserting the implantable thoracic duct pump device into the right subclavian vein along the first guide wire; advancing the implantable thoracic duct pump device into a flush seal against the ostium of the thoracic duct; and wherein the implantable thoracic duct pump device includes: a fluid micropump sized and shaped to be implanted in a vein adjacent to the thoracic duct ostium, the fluid micropump including a motor inlet and a motor outlet; a thoracic duct cannula in fluid communication with the motor inlet; and a duct seal surrounding an exterior of the thoracic duct cannula and configured to form a seal in a thoracic duct, wherein the duct seal is sized and shaped to seal the ostium of the thoracic duct when the implantable thoracic duct pump device is implanted in the thoracic duct of a subject.

[0031] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary 3915-P1359WO.UW -5-is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. DESCRIPTION OF THE DRAWINGS

[0032] The foregoing aspects and many of the attendant advantages of the present disclosure will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

[0033] FIG.1A is a schematic view of an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0034] FIG.1B is a schematic view of an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0035] FIG.2 is a schematic view of the position of implantation near the thoracic duct of an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0036] FIG. 3 is a schematic view of an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0037] FIG.4A is a perspective view of a contoured sealing ring according to an embodiment of the present disclosure;

[0038] FIG.4B is a perspective view of a contoured sealing ring according to an embodiment of the present disclosure;

[0039] FIG.4C is a side view of a coupling of the contoured sealing ring of FIG. 4B to a vein according to an embodiment of the present disclosure;

[0040] FIG.4D is a top schematic view of a contoured sealing ring according to an embodiment of the present disclosure;

[0041] FIG. 4E is a top schematic view of a contoured sealing ring according to an embodiment of the present disclosure;

[0042] FIG.5A is a schematic view of an implantation of an implantable thoracic duct pump device at a thoracic duct according to an embodiment of the present disclosure;

[0043] FIG.5B is a schematic view of an implantation of an implantable thoracic duct pump device at a thoracic duct according to an embodiment of the present disclosure;

[0044] FIG. 6 is a schematic view of an implantation of an implantable thoracic duct pump device at a thoracic duct according to an embodiment of the present disclosure; 3915-P1359WO.UW -6-

[0045] FIG. 7 is a schematic view of an implantation of an implantable thoracic duct pump device at a thoracic duct according to an embodiment of the present disclosure;

[0046] FIG. 8 is a schematic view of an implantation of an implantable thoracic duct pump device at a thoracic duct according to an embodiment of the present disclosure;

[0047] FIG. 9 is a schematic view of a portion of an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0048] FIG. 10A is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0049] FIG. 10B is an ultrasound image of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0050] FIG. 10C is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0051] FIG. 10D is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0052] FIG. 10E is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0053] FIG. 10F is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0054] FIG. 10G is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0055] FIG. 10H is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0056] FIG. 10I is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure; 3915-P1359WO.UW -7-

[0057] FIG. 11A is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0058] FIG. 11B is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0059] FIG. 11C is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0060] FIG. 11D is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0061] FIG. 11E is a schematic illustration of a step of a method for implanting an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0062] FIG. 12 is a schematic outlining various installation methods for an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0063] FIG. 13A is a schematic block diagram depicting a bench test configuration of an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0064] FIG. 13B is a block diagram depicting a method for a bench test of an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0065] FIG.13C is a schematic illustration of a front view of a duct seal according to an embodiment of the present disclosure;

[0066] FIG.13D is a schematic illustration of a side view of the duct seal of FIG. 13C according to an embodiment of the present disclosure;

[0067] FIG.14A is an operational test sealing efficiency curve depicting a sealing efficiency of the implantable thoracic duct pump device of FIG.13A.

[0068] FIG. 14B is a theoretical curve for a properly working seal and pump of an implantable thoracic duct pump device according to an embodiment of the present disclosure; 3915-P1359WO.UW -8-

[0069] FIG. 14C is a theoretical curve for an improper seal of an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0070] FIG.14D is a theoretical curve for a weak pump of an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0071] FIG. 14E is a theoretical curve for an overpowered pump of an implantable thoracic duct pump device according to an embodiment of the present disclosure;

[0072] FIG.15 is an operational test sealing efficiency curve depicting a sealing efficiency of a bench test of an implantable thoracic duct pump device with only an internal intraductal seal according to an embodiment of the present disclosure; and

[0073] FIG.16 is an operational test sealing efficiency curve depicting a sealing efficiency of a bench test of an implantable thoracic duct pump device with only an external venous seal according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0074] Listing of Drawing Elements: 100 implantable thoracic 400 contoured sealing ring 700 implantable thoracic g g3915-P1359WO.UW -9-110' sealing balloon 500 implantable thoracic 814 thoracic duct cannula 112' first inlet duct um device 900 im lantable thoracic gthe alleviation of diuretic refractory fluid overload provides utility in chronic heart failure, but is not exclusive to this, and may also have utility in other conditions involving fluid retention including conditions related to ascites, right heart failure, Fontan in addition to other conditions.

[0076] As used herein the terms "subject" and "patient" refer to a person or animal in which the implantable thoracic duct pump device may be implanted, and as such these terms may be used interchangeably unless otherwise noted. 3915-P1359WO.UW -10-

[0077] In brief, the overall design of the pump involves an inlet cannula within the thoracic duct that is attached to a microfluidic pump just outside of the lymphatic duct outlet within the venous system. In some embodiments, the overall design of the pump involves an inlet cannula positioned at the ostium of the thoracic duct that is attached to a microfluidic pump just outside of the lymphatic duct outlet within the venous system. Thus, this approach allows the drainage of lymphatic fluid from the thoracic duct, into the venous system.

[0078] A technique of sealing off the thoracic duct, such as but not limited to the use of a duct seal surrounding the thoracic duct cannula, has several advantages. Some advantages include: that it allows the generation of significant pressure differential between the venous system and the thoracic duct, thereby improving lymphatic flow and creating negative pressure within the duct; and that the seal around the cannula within the thoracic duct significantly improves the efficiency of the pump system since there is minimal backflow of fluid that would impede the generation of the pressure differential, which allows the use of smaller pumps with smaller battery requirements. Such a pressure differential can aid with fluid mobilization from tissues.

[0079] The thoracic duct pump device of the present disclosure can be implanted via a catheter-based approach, a surgical approach, or a hybrid approach, though it is to be understood that any implantation method can be utilized.

[0080] FIG.1 is a schematic view of an implantable thoracic duct pump device 100 according to an embodiment of the present disclosure. The implantable thoracic duct pump device 100 includes a fluid micropump 102, a thoracic duct cannula 114, and a duct seal (such as contoured sealing ring 108 and / or sealing balloon 110) configured to form a seal in a thoracic duct T. In an embodiment, the duct seal surrounds an exterior of the thoracic duct cannula 114, thereby forming the seal.

[0081] The fluid micropump 102 includes a motor inlet 104 and a motor outlet 106. In some embodiments, the motor inlet 104 is in fluid communication with the thoracic duct cannula 114. In some embodiments, the motor inlet 104 is directly coupled to an outlet of the thoracic duct cannula 114. In some embodiments, the motor inlet 104 abuts the outlet of the thoracic duct cannula 114 at a position that is substantially co-planar with an ostium of the thoracic duct T. An advantage of such a configuration is that the fluid micropump 102 may be positioned directly against a vein wall at the ostium of the thoracic duct T, thereby improving the sealing of the duct seal while minimizing obstructions to flow of 3915-P1359WO.UW -11-blood past the fluid micropump 102. Another advantage is that the fluid micropump 102 may be more fully integrated into the vein wall to improve the coupling of the implantable thoracic duct pump device 100 to the thoracic duct T.

[0082] In some embodiments, the motor outlet 106 is fluidly coupled to the veins of a patient, such as the subclavian vein. In this regard, the fluid micropump 102, when in operation, draws lymphatic fluid through the thoracic duct cannula 114 and the motor inlet 104, then subsequently exudes the lymphatic fluid through the 106 into the blood flow of the veins of the patient.

[0083] In some embodiments, the fluid micropump 102 is catheter implantable. In some embodiments, the fluid micropump is disposed within the subclavian vein such as at the ostium of the thoracic duct T.

[0084] The duct seal may be sized and shaped to seal the ostium of the thoracic duct T when the implantable thoracic duct pump device 100 is implanted in the thoracic duct T of a subject. Without wishing to be bound by any particular theories, sealing of the ostium may be advantageous in preventing the backflow of blood from the venous system into the thoracic duct T during operation of the implantable thoracic duct pump device 100.

[0085] In this regard, in some embodiments, the implantable thoracic duct pump device further comprises a duct-cannula retainer, such as sealing balloon 110. In some embodiments, the size of sealing balloon 110 is such that, when the thoracic duct cannula 114 cannulates the thoracic duct T, the sealing balloon 110 does not impede the cannulation. However, once inflated, the size of the sealing balloon 110 is such that it presses firmly, but non-destructively, against the walls of the thoracic duct T. In some embodiments, the shape of the sealing balloon is such that a sufficient portion of the sealing balloon 110 presses against the walls of the thoracic duct T so as to prevent the flow of blood and lymphatic fluid through the ostium of the thoracic duct T except as directed through the fluid micropump 102. In such embodiments, when the thoracic duct cannula 114 cannulates the thoracic duct T, the sealing balloon 110 may be inflated, thereby preventing flow of lymphatic fluids from entering the venous system via routes other than through the implantable thoracic duct pump device 100, and at the same time preventing flow of blood into the thoracic duct T.

[0086] In some embodiments the duct-cannula retainer may further comprise a sleeve (such as sleeve 122') positioned on an exterior of the duct-cannula retainer, such as sealing balloon 110. The sleeve 122' may then contact with the walls of the thoracic duct 3915-P1359WO.UW -12-T to create additional retaining forces such that the implantable thoracic duct pump device 100 is securely implanted.

[0087] In some embodiments, the duct seal comprises a sealing ring, such as contoured sealing ring 108. In some embodiments, the duct seal comprises a flange, which in some embodiments may be an example of contoured sealing ring 108, that is sized and shaped to lay along a vein wall immediately adjacent to the thoracic duct ostium, such that it can facilitate pressure reduction of the lymphatic system beginning immediately at the terminal thoracic duct ostium without blocking lymphatic channels that connect towards the end of the terminal thoracic duct. Because the ostium of the thoracic duct T is positioned at the junction between the internal jugular vein, the left subclavian vein, and the brachiocephalic vein (such as internal jugular vein Vj, left subclavian vein Vs, and brachiocephalic vein Vb depicted in FIG. 2), when the duct seal comprises a contoured sealing ring 108, the size of the contoured sealing ring 108 is such that contact is made with the venous walls in a manner that substantially surrounds the ostium of the thoracic duct T. Moreover, the contoured sealing ring 108 is sufficiently large so that it may be joined to the venous walls either percutaneously or surgically with sufficient strength to avoid becoming dislodged, yet sufficiently small so that it does not impede the flow of blood through the venous system, as will be described further below with respect to FIG. 4A - FIG.5B.

[0088] Without wishing to be bound by any particular theory, an embodiment relying solely on the contoured sealing ring allows for the selective negative pressure within the lymphatic system beginning directly at the ostium of the thoracic duct. On the other hand, the embodiment with both a sealing balloon and a contoured sealing ring provides for additive separation between the lymphatic and venous system.

[0089] In some embodiments, the duct seal surrounds an exterior of the thoracic duct cannula and is configured to form a seal in a thoracic duct. Without wishing to be bound by any particular theory, the duct seal allows for the selective reduction of pressure within the thoracic duct. Additionally, by forming a seal in the thoracic duct, backflow between the thoracic duct and the venous system of a patient that would otherwise be caused by the reduced thoracic duct pressure is reduced.

[0090] In some embodiments, the duct seal comprises a sealing balloon 110. In some embodiments, the sealing balloon 110 is an angioplasty balloon. In some embodiments, an external surface of the sealing balloon comprises a texture configured to 3915-P1359WO.UW -13-provide friction with an internal lumen of the thoracic duct. In some embodiments, the texture comprises a ribbing, a pebbling, or a sandpaper texture.

[0091] In some embodiments, such as that of FIG. 1A, the duct seal comprises both contoured sealing ring 108 and sealing balloon 110. In some embodiments, the duct seal further comprises a sleeve. However, in some embodiments, such as that of FIG. 1B, FIG. 2, and FIG. 3, the duct seal comprises only the sealing balloon 110. In some embodiments, such as those of FIG.5A - FIG.9, the duct seal comprises only the contoured sealing ring 108.

[0092] In some embodiments, the duct seal comprises a contoured sealing ring configured to seal an ostium of the thoracic duct. In some embodiments, the contoured sealing ring has a clam shell shape. In an embodiment, the contoured sealing ring is configured to be non-planar. In some embodiments, the contoured sealing ring has a saddle shape configured to seal the thoracic duct at the junction between the internal jugular vein and subclavian vein, such as internal jugular vein Vj and left subclavian vein Vs described with respect to FIG.2, below.

[0093] In some embodiments, a power supply cable 116 is connected to the fluid micropump 102, wherein the power supply cable 116 is in electrical communication with a power source. In some embodiments, the power source is a battery sized and shaped for subcutaneous implantation. For instance, a size of the battery may be sufficiently thin so as to be embeddable subcutaneously without causing undue discomfort to a patient, in a manner analogous to an installation of a pacemaker. The shape of the battery may be low profile and with a cross section that avoids protrusions from the patient. In some embodiments, an external power source is used, such as for hospitalized patients. In some embodiments, a larger external battery is used, such as in the outpatient situation.

[0094] In this regard, FIG.1B is a schematic view of an implantable thoracic duct pump device 100' according to an embodiment of the present disclosure. In some embodiments, the implantable thoracic duct pump device 100' of FIG.1B is an example of the implantable thoracic duct pump device 100 of FIG. 1A. In this regard, analogous structure features are represented with like numerals, but in the 1XX' series. In some embodiments, a sleeve 122' is disposed on an exterior surface of the sealing balloon 110' and is configured to retain the sealing balloon 110' in a stationary configuration within the thoracic duct T. In some embodiments, the sleeve 122' comprises a sleeve texture 3915-P1359WO.UW -14-configured to provide friction with an internal lumen of the thoracic duct. In some embodiments, the sleeve texture comprises a ribbing, a pebbling, or a sandpaper texture.

[0095] FIGURE 2 illustrates a schematic view of the position of implantation near the thoracic duct of an implantable thoracic duct pump device 200 according to an embodiment of the present disclosure. In this regard, implantable thoracic duct pump device 200 is another example of a thoracic duct pump device such as implantable thoracic duct pump device 100, described with respect to FIG.1A. Accordingly, analogous structure features are represented with like numerals, but in the 2XX series.

[0096] In some embodiments, the fluid micropump 202 is sized and shaped to be implantable within the brachiocephalic vein and near the intersection of the left subclavian vein Vs, the brachiocephalic vein Vb, and the internal jugular vein Vj, and at the entrance of the thoracic duct T. In some embodiments, the fluid micropump 202 is sized and shaped to be implantable within the left subclavian vein Vs. In some embodiments, the fluid micropump 202 is sized and shaped to be implantable within the internal jugular vein Vj. A first inlet 212 of a thoracic duct cannula 214 is shown to be in fluid communication with the motor inlet, and motor outlet 206 is shown to be in fluid communication with veins Vb, Vj, and Vs. In some embodiments, the thoracic duct cannula 214 is inserted inside the thoracic duct T. In some embodiments the motor inlet is in fluid communication with the thoracic duct without insertion of the thoracic duct cannula 214. Sealing balloon 210 is depicted to form a seal near the ostium O of the thoracic duct T.

[0097] FIG. 3 provides a schematic view of another implantable thoracic duct pump device 300 according to an embodiment of the present disclosure. In some embodiments, the implantable thoracic duct pump device 300 of FIG. 3 is an example of the implantable thoracic duct pump device 100 of FIG. 1A. In this regard, analogous structure features are represented with like numerals, but in the 3XX series.

[0098] Implantable thoracic duct pump device 300 includes an alternative configuration for the motor outlet 306. Motor outlet 306 includes multiple outlet lumens along a side portion of the fluid micropump 302. Without wishing to be bound by any particular theory, an advantage of such a configuration is a decreased impedance to the outflow of lymphatic fluid, thereby improving the efficiency of the implantable thoracic duct pump device 300.

[0099] Implantable thoracic duct pump device 300 further includes propeller housing 318, and in this regard, implantable thoracic duct pump device 300 includes a fluid 3915-P1359WO.UW -15-micropump 302 that operates with a propeller motor. However, it should be understood that other pump mechanisms are within the reach of one of ordinary skill in the art and thus fall within the scope of the present disclosure.

[0100] FIG.4A depicts a contoured sealing ring 400. In some embodiments, the contoured sealing ring 400 is an example of contoured sealing ring 108 as described above with respect to FIG.1A. Contoured sealing ring 400 includes a membrane 402, a plurality of right-angle teeth 404, and a center 406. Contoured sealing ring 400 may be sized and shaped to be implanted via any of the methods described in the present disclosure, such as the methods discussed with respect to FIG.10A – FIG.11E, or via surgical placement.

[0101] The material for membrane 402 is selected to be sufficiently flexible so that contoured sealing ring 400 may conform to a surface near the ostium of the thoracic duct when implanted / pressed against the vein surface near the ostium. In this regard, membrane 402 may comprise or be otherwise formed from expanded polytetrafluoroethylene (ePTFE), silicone, or another biocompatible membrane material An implantable thoracic duct pump device, such as implantable thoracic duct pump device 100, may be configured to be embedded at the center 406 of the contoured sealing ring 400, such that all lymphatic fluid in the thoracic duct flows substantially through the implantable thoracic duct pump device in its transit to the veins of the patient.

[0102] The contoured sealing ring 400 is configured to attach to the vein of a patient to form a seal with the ostium of the thoracic duct. In this regard, the plurality of right-angle teeth 404 may have a tooth height and tooth angle, such as a right angle, sufficient to embed in the vein wall of a patient, such as without causing damage to the vein wall of the patient.

[0103] In this regard, FIG. 4B depicts contoured sealing ring 400'. In some embodiments, contoured sealing ring 400' is an example of contoured sealing ring 400, where analogous structures are depicted with analogous numerals except in the 4xx' series. Contoured sealing ring 400' includes a plurality of back angle teeth 404' instead of right- angle teeth 404. Without wishing to be bound by any particular theory, the back angle teeth 404' may implant in the walls of the veins of a patient and form a tight coupling by virtue of the back angle bite of the back angle teeth 404', as is best illustrated in FIG. 4C. Decoupling of the contoured sealing ring 400' from the venous wall may be resisted by the embedding of the back angle teeth 404'. In some embodiments, contoured sealing ring 400' 3915-P1359WO.UW -16-may include a suturable ring (not pictured) along the perimeter defined by back angle teeth 404', where the suturable ring is sized and shaped for surgical implantation.

[0104] While contoured sealing ring 400 and contoured sealing ring 400' are depicted to include substantially circular membrane 402 and membrane 402', the contoured sealing rings of the present disclosure may take on any size and shape suitable for sealing the thoracic duct of a patient. In this regard, FIG.4D depicts a contoured sealing ring 400'' where the 402'' defines a rhomboid shape with curved edges. In some embodiments, contoured sealing ring 400'' is an example of contoured sealing ring 400, where analogous structures are depicted with analogous numerals except in the 4xx'' series.

[0105] In contoured sealing ring 400'', a number or tack point 404'' are positioned at a vertex between adjacent sides of the membrane 402''. These tack points 404'' may include one or more teeth, such as was depicted in right angle teeth 404 and back angle teeth 404'. Without wishing to be bound by any particular theory, tack points 404'' may allow the membrane 402'' to curve around the contours of the walls of the venous system of the patient by forming a plurality of taught coupling points. Advantageously, such a configuration requires fewer insertions into the venous walls of the patient, thereby reducing the intrusive effect of installing the implantable thoracic duct pump device while providing for easier removal if the procedure needed to be reversed.

[0106] As a further example, 400''' is depicted in FIG.4E. In some embodiments, contoured sealing ring 400''' is an example of contoured sealing ring 400, where analogous structures are depicted with analogous numerals except in the 4xx''' series. In contoured sealing ring 400''', the membrane 402''' defines an oval shape. In this regard, tack points 404''' may allow the membrane 402'' to curve around the contours of the walls of the venous system of the patient by forming a plurality of taught coupling points. Advantageously, such a configuration requires fewer insertions into the venous walls of the patient, thereby minimizing the intrusive effect of installing the implantable thoracic duct pump device while providing for easier removal if the procedure needed to be reversed.

[0107] FIG.5A is a schematic view of an implantation of an implantable thoracic duct pump device 500 at a thoracic duct T according to an embodiment of the present disclosure. In some embodiments, implantable thoracic duct pump device 500 is an example of implantable thoracic duct pump device 100. Accordingly, analogous structures of implantable thoracic duct pump device 500 will be described with analogous numbering to implantable thoracic duct pump device 100 except in the 5xx series. 3915-P1359WO.UW -17-

[0108] As depicted in FIG. 5A, implantable thoracic duct pump device 500 includes contoured sealing ring 508 which is configured to form a seal around an ostium of the thoracic duct T at the base of a fluid micropump 502. Coupled to contoured sealing ring 508 are first brace 509a and second brace 509b. First brace 509a and second brace 509b are fixedly coupled to the contoured sealing ring 508 and are sized and shaped to provide additional pressure against the contoured sealing ring 508 to improve the sealing efficiency of contoured sealing ring 508 against the ostium of the thoracic duct T.

[0109] In this regard, in some embodiments, contoured sealing ring 508 contacts a first surface of the venous wall of a patient. First brace 509a and second brace 509b may thereafter be extendable across a diameter of a vein of the patient, such that a surface of first brace 509a may contact a second surface opposed from a first portion of the first surface, such as substantially diametrically opposed, and such that a surface of the second brace 509b may contact a third surface diametrically opposed from a second portion of the first surface. In this manner, the first brace 509a and second brace 509b provide additional securing force to the contoured sealing ring 508 to retain the contoured sealing ring 508 in position to seal the thoracic duct T.

[0110] In the illustrated embodiment, first brace 509a is configured to contact a second surface comprising a venous wall of the left subclavian vein Vs, and the second brace 509b is configured to contact a third surface comprising a venous wall of the internal jugular vein Vj. However, it should be understood that alternative configurations of braces contacting venous walls are within the scope of the present disclosure. Similarly, more than two braces may be used, such as a third brace, a fourth brace, a fifth brace, a sixth brace, and more. In some embodiments, additional braces may improve the sealing efficiency, while at the same time individually requiring each brace to provide less individual sealing force. In such configurations, smaller additional braces may be advantageously used.

[0111] It should also be understood that alternative structures for the sealing braces may be used. In this regard, FIG.5B provides a schematic view of an implantation of an implantable thoracic duct pump device 500' at a thoracic duct T according to an embodiment of the present disclosure. In some embodiments, implantable thoracic duct pump device 500' is an example of implantable thoracic duct pump device 500. Accordingly, analogous structures of implantable thoracic duct pump device 500' will be described with analogous numbering to implantable thoracic duct pump device 500 except in the 5xx' series. 3915-P1359WO.UW -18-

[0112] Implantable thoracic duct pump device 500' includes first brace 509a' and second brace 509b'. Each of 509a' and second brace 509b' are depicted to include a self- expanding stent matrix and a bio-integrable outer surface configured to contact a surface of the venous wall and be incorporated therein. An advantage of first brace 509a' and second brace 509b' is that the pressure applied to secure the contoured sealing ring 508' against the venous wall at the ostium of the thoracic duct T may be diffusely distributed across a circumference of the venous wall. In this regard, in some embodiments, the first brace 509a' and second brace 509b' are more readily integrated into the body of the patient.

[0113] Moreover, while FIG. 5A and FIG. 5B depict implantable thoracic duct pump device 500 and implantable thoracic duct pump device 500' to include either first brace 509a and second brace 509b, or first brace 509a' and second brace 509b', it should be understood that other combinations are possible, such as where a combination of first brace 509a, second brace 509b, first brace 509a', and second brace 509b' are used. Additionally, more than two braces may be used, such as a third brace, a fourth brace, a fifth brace, a sixth brace, and more. In this manner, the particular configuration of braces may be optimized to secure the implantable thoracic duct pump device 500 or implantable thoracic duct pump device 500' in place.

[0114] Referring next to FIG. 6 – FIG. 9, various configurations of the thoracic duct cannula are described. FIG. 6 provides a schematic view of an implantation of an implantable thoracic duct pump device 600 at a thoracic duct T according to an embodiment of the present disclosure. In some embodiments, implantable thoracic duct pump device 600 is an example of implantable thoracic duct pump device 100. Accordingly, analogous structures of implantable thoracic duct pump device 600 will be described with analogous numbering to implantable thoracic duct pump device 100 except in the 6xx series.

[0115] Implantable thoracic duct pump device 600 includes duct-cannula retainer 611 which is couplable to thoracic duct cannula 614. In some embodiments, duct-cannula retainer 611 may be a balloon, such as an angioplasty balloon. In this regard, duct-cannula retainer 611 may be an example of balloon 110. In some embodiments, duct-cannula retainer 611 may be a porous or matrix-like positioning piece sized and shaped to occupy any space between the inlet cannula and the internal diameter of the thoracic duct, thereby positioning the thoracic duct cannula 614 substantively in the center of the thoracic duct T. An advantage of this configuration is that the first inlet 612 of the thoracic duct cannula 3915-P1359WO.UW -19-614 may be kept clear from any partial obstructions that may occur, such as due to an at least partial interaction or contact with a wall of the thoracic duct T.

[0116] For instance, in the illustrated embodiment, the thoracic duct T has an inner diameter of about 4 mm and the thoracic duct cannula 614 has an outer diameter of about 2.5 mm. In this manner, a gap is defined between the inner surface of the thoracic duct T and the outer surface of the thoracic duct cannula 614 of about 0.75 mm. It should be noted that, while specific dimensions are recited for clarity, the outer diameter of the thoracic duct cannula 614 is not limited to the diameter described in the above embodiments, and that other suitable diameters for the thoracic duct cannula 614 may be used, including uniform diameter embodiments of the thoracic duct cannula 614, as well as tapered and / or variable diameter thoracic duct cannulas 614.

[0117] In some embodiments, such as where duct-cannula retainer comprises a sealing balloon, duct-cannula retainer 611 may provide an additional securing force to prevent the implantable thoracic duct pump device 600 from becoming dislodged. Moreover, duct-cannula retainer 611 may help improve the sealing efficiency, such as from contoured sealing ring 608. In this regard, in some embodiments, duct-cannula retainer 611 may be used in place of the first brace 509a, second brace 509b, first brace 509a', and second brace 509b' described above with respect to FIG. 5A and FIG. 5B. In some embodiments, duct-cannula retainer 611 is a supplemental feature to the first brace 509a, second brace 509b, first brace 509a', and second brace 509b'.

[0118] Moreover, while the fluid micropump 602 of the implantable thoracic duct pump device 600 is depicted as abutting the contoured sealing ring 608 and the surface of the venous wall near the ostium of the thoracic duct T, other configurations and positions of the fluid micropump 602 are possible and are within the scope of the present disclosure. In this regard, FIG. 7 provides a schematic view of an implantation of an implantable thoracic duct pump device 700 at a thoracic duct T according to an embodiment of the present disclosure. In some embodiments, implantable thoracic duct pump device 700 is an example of implantable thoracic duct pump device 600. Accordingly, analogous structures of implantable thoracic duct pump device 700 will be described with analogous numbering to implantable thoracic duct pump device 600 except in the 7xx series.

[0119] In implantable thoracic duct pump device 700, the fluid micropump 702 is disconnected from the contoured sealing ring 708. The thoracic duct cannula 714 extends from the thoracic duct T, through the ostium, through the contoured sealing ring 708, and 3915-P1359WO.UW -20-through at least a portion of the vein, such as brachiocephalic vein Vb. In this regard, the implantable thoracic duct pump device 700 may be positioned at a distance from the ostium of the thoracic duct T. Without wishing to be bound by any particular theory, such a configuration may have the advantage of allowing the fluid micropump 702 to be positioned advantageously in a particular flow path of the venous system. For instance, the fluid micropump 702 may be positioned so that lymphatic fluid is outflowed in the brachiocephalic vein Vb, the left subclavian vein Vs, or the internal jugular vein Vj. Along similar lines, the thoracic duct cannula 714 may extend further, allowing the fluid micropump 702 to be positioned elsewhere in a body of the patient.

[0120] In some embodiments, the thoracic duct cannula may include more than one inlet, such as to provide additional access points for lymphatic fluid and to decrease impedance to flow through the fluid micropump. In this regard, FIG.8 provides a schematic view of an implantation of an implantable thoracic duct pump device 800 at a thoracic duct T according to an embodiment of the present disclosure. In some embodiments, implantable thoracic duct pump device 800 is an example of implantable thoracic duct pump device 600. Accordingly, analogous structures of implantable thoracic duct pump device 800 will be described with analogous numbering to implantable thoracic duct pump device 600 except in the 8xx series.

[0121] In implantable thoracic duct pump device 800, the thoracic duct cannula 814 is positioned in an off-center configuration within the thoracic duct T. The duct- cannula retainer 811 substantively retains the thoracic duct cannula 814 in place within the thoracic duct T. However, unlike duct-cannula retainer 611, duct-cannula retainer 811 is sized and shaped to expand differentially through the thoracic duct T to retain the thoracic duct cannula 814 in an off-center configuration. An advantage to the off-center configuration is that a firmer connection may be formed between an outer wall of the thoracic duct cannula 814 and the inner wall of the thoracic duct T. This may advantageously improve the retention of the thoracic duct cannula 814 in the thoracic duct T and therefore prevent the implantable thoracic duct pump device 800 from becoming dislodged.

[0122] The inlet of the thoracic duct cannula 814 includes a first inlet 812a and a second inlet 812b. In the illustrated embodiment, the second inlet 812b is defined in the thoracic duct cannula 814 proximal the first inlet 812a. However, it should be understood that second inlet 812b may be formed in other locations along the thoracic duct cannula 3915-P1359WO.UW -21-814, such as at a substantive midpoint of the thoracic duct cannula 814, or proximal the contoured sealing ring 808 and motor inlet 804. In some embodiments, the second inlet 812b defines a lumen configured to reduce impediment of lymphatic flow from small lymphatic vessels that fluidly connect to the ostium of the thoracic duct. In some embodiments, the lumen, such as second inlet 812b, is disposed adjacent to the contoured sealing ring. Without wishing to be bound by any particular theory when second inlet 812b is disposed adjacent to the contoured sealing ring, it enables the implantable thoracic duct pump device 800 to relieve localized pressure of the small lymphatic channels that connect between where the thoracic duct is sealed and the sealing ring around the ostium.

[0123] While the illustrated embodiment depicts more than one inlet when the thoracic duct cannula 814 is in an off-center configuration, it should be understood that embodiments with more than one inlet may be used also in the centered configuration. Additionally, while FIG. 8 depicts one second inlet 812b, it should be understood that additional inlets may be disposed in the thoracic duct cannula 814, such as in the device described more in FIG.9.

[0124] FIG. 9 provides a schematic view of the thoracic duct cannula portion of a thoracic duct pump device 900 according to an embodiment of the present disclosure. In some embodiments, implantable thoracic duct pump device 900 is an example of implantable thoracic duct pump device 600. Accordingly, analogous structures of implantable thoracic duct pump device 900 will be described with analogous numbering to implantable thoracic duct pump device 600 except in the 9xx series.

[0125] Implantable thoracic duct pump device 900 includes a plurality of second inlets 912b. Each inlet of the plurality of second inlets 912b defines a lumen through which lymphatic fluid may be drawn; these plurality of second inlets 912b are disposed along the outer wall of the thoracic duct cannula 914, such as in a regularly spaced geometric packing arrangement. Without wishing to be bound by any particular theory, an advantage of such a configuration is that thoracic duct cannula 914 may be universally deployed despite minor variations in the positioning of smaller lymphatic vessels near the ostium of the thoracic duct. Regardless of where lymphatic flow enters the thoracic duct, the second inlets 912b are configured to permit flow into the thoracic duct cannula 914 and out through the fluid micropump.

[0126] METHOD OF IMPLANTATION 3915-P1359WO.UW -22-

[0127] In an aspect, the present disclosure relates to a method of implanting an implantable thoracic duct pump device. In that regard, FIG.10A – FIG.10I and FIG.11A – FIG. 11E provide schematic illustrations of steps that may be performed during the implantation of an implantable thoracic duct pump device, such as any of the implantable thoracic duct pump devices described herein, and in particular implantable thoracic duct pump device 600. Accordingly, while the methods described herein may be implemented with any of the implantable thoracic duct pump devices described in the present disclosure, for clarity, reference will be made to implantable thoracic duct pump device 600.

[0128] FIG. 10A depicts a location on a neck of a patient where an initial transcervical access injection may be made during the implantation of an implantable thoracic duct pump device. The arrow indicates a position on the neck of the patient where transcervical access injection may be made for transcervical percutaneous access.

[0129] FIG. 10B depicts an example of an ultrasound guided micropuncture for an internal jugular vein access catheterization. The solid arrow indicates The position of the thoracic duct, while the dashed arrow indicates a direction for a needle to be inserted into the thoracic duct.

[0130] FIG. 10C depicts a schematic illustration of injection access into the thoracic duct of a patient via transcervical access. The injection point in the left thoracic duct is proximal where the thoracic duct connects to the venous system near the jugular vein, the subclavian vein, and the brachiocephalic vein.

[0131] FIG. 10D depicts a micropuncture access into the right side of the chest of a patient. An injection is used to make micropuncture access into the venous system. Following micropuncture access, wiring is inserted, and a guide catheter is advanced into the veins. In some embodiments, access to the right side may be performed in the manner a pacemaker is implanted, but on the right side of the chest.

[0132] FIG. 10E depicts the extension of wiring from the thoracic duct to the vein. The injection process through the transcervical access point on the left side of the chest guides a wire through the thoracic duct and the ostium of the thoracic duct and out into the venous system. A thin catheter may then be subsequently advanced over the wire, thereby providing ongoing thoracic duct access.

[0133] FIG. 10F depicts how the access from the right side of the chest via the jugular vein and access on the left side via the thoracic duct are connected. A snare is advanced from the right side of the chest and the jugular vein to the brachiocephalic vein. 3915-P1359WO.UW -23-The snare is sized and shaped to couple to the wiring advanced from the left side of the neck through the thoracic duct. The thoracic duct wire is snared by the snare introduced in the right side of the chest. Once the thoracic duct wire has been snared, the snare may be drawn out through the right subclavian access point, thereby providing a continuous access wire from the thoracic duct access to the right subclavian access point.

[0134] FIG.10G depicts the guidewire from the thoracic duct as it is extended to the right subclavian access point. A small thoracic duct sheath is set in place, while a larger right subclavian sheath is set in place to permit access for larger systems to be implanted.

[0135] FIG. 10H depicts the implantable thoracic duct pump device 600 being advanced through the left brachiocephalic vein of the patient and into the thoracic duct of the patient.

[0136] FIG. 10I depicts the duct-cannula retainer 611 in its delivered state. Ultrasound may be used to confirm that the duct-cannula retainer 611 is in place and is holding the implantable thoracic duct pump device 600 in position in the ostium of the thoracic duct. Once fully deployed, the transcervical thoracic duct access sheath may be removed. The fluid micropump 602 may then be turned on and placement and flow may subsequently be confirmed by ultrasound. The powered-on fluid micropump 602 begins drawing flow of lymphatic fluid into the first inlet 612 and out through motor outlet 606.

[0137] Referring next to FIG.11A – FIG.11E, an alternative implantation design is described for an implantable thoracic duct pump device where the fluid micropump is in an externally-disposed configuration.

[0138] In this regard, FIG. 11A depicts the relevant anatomical regions for a second implantation design, highlighting the junction between the left internal jugular vein, the left subclavian vein, and the brachiocephalic vein from the venous system, and the joining junction of the thoracic duct to the junction between these three veins.

[0139] FIG. 11B illustrates an insertion step of a wire into the thoracic duct, through the ostium of the thoracic duct, and into the brachiocephalic vein. On the other side, a snare is inserted through the right subclavian vein, up through the brachiocephalic vein, and into a position where the snare is configured to contact the wire.

[0140] In FIG.11C, the wire is drawn back out through the right subclavian vein. A cannula is inserted at access sites on both the left neck and right side of the chest of a patient to retain access to the thoracic duct on the one side and the right subclavian vein on 3915-P1359WO.UW -24-the other. The implantable thoracic duct pump device is then inserted along the wire and into the right subclavian vein.

[0141] In FIG. 11D, the implantable thoracic duct pump device is inserted into the ostium of the thoracic duct. The duct seal and / or duct-cannula retainer may then be deployed to retain the implantable thoracic duct pump device within the thoracic duct. A power supply cable may be subsequently connected to a power source, such as an external pocket containing a pump and a battery.

[0142] FIG.11E depicts a schematic of a fully deployed implantable thoracic duct pump device. The thoracic duct cannula is implanted in the thoracic duct and sealed at the lympho-venous junction. The power supply cable connects to an outlet cannula in the subclavian vein and on to an external pump and battery. An advantage of this implantation method is that the pump and / or battery may be replaced without replacing the duct seal.

[0143] In another aspect, the implantable thoracic duct pump device, such as implantable thoracic duct pump device 600, may be surgically implanted. For instance, the thoracic duct pump device 600 may be implanted via venous access from a left neck dissection. In some embodiments, a hybrid procedure may be used that is combination of surgical access and any of the method steps described with respect to FIG.10A – FIG.10I and FIG.11A – FIG.11E.

[0144] METHOD OF ALLEVIATING DIURETIC REFRACTORY FLUID OVERLOAD

[0145] In this regard, in an aspect, the present disclosure provides method of alleviating diuretic refractory fluid overload. In an embodiment, the method comprises providing an implantable thoracic duct pump device external to the thoracic duct outlet within a venous system of a patient, and generating a pressure differential between the venous system and the thoracic duct of the patient, thereby facilitating lymphatic flow into the venous system. In some embodiments, the implantable thoracic duct pump device is an example of any of the implantable thoracic duct pump devices described herein. Moreover, Examples 1 and 2 provide examples of the implantation and operation of the implantable thoracic duct pump device in a benchtop setup.

[0146] EXAMPLES

[0147] Example 1: Powering of device in a thoracic duct

[0148] FIGURE 12 is a schematic outlining various additional installation methods for an implantable thoracic duct pump device according to an embodiment of the 3915-P1359WO.UW -25-present disclosure. In some embodiments, the implantable thoracic duct pump device of the present disclosure can be implanted by cannulation. In an embodiment, the implantable thoracic duct pump device is inserted through the right jugular vein or a connected right- sided vein attached to a wire. The wire subsequently drops down and into the left brachiocephalic vein and then is extended into position to cannulate the thoracic duct. In an embodiment, the implantable thoracic duct pump device is inserted through the left subclavian vein attached to a wire and then is extended into position to cannulate the thoracic duct. In an embodiment, the implantable thoracic duct pump device is inserted through the right subclavian vein attached to a wire and then is extended into position to cannulate the thoracic duct.

[0149] Example 2: Bench test of implantable thoracic duct pump device

[0150] To demonstrate the efficiency of the seals of an implantable thoracic duct pump device according to an embodiment of the present disclosure, a bench test was performed according to FIG.13A - FIG.6.

[0151] In this regard, FIG.13A depicts a block diagram of a bench test setup for the implantable thoracic duct pump device. A reservoir and bladder combination is depicted on one side of a seal, representing the bodily systems of the cisterna chyli and the thoracic duct. A first pump flows fluid from the reservoir into the bladder, which approximates the function of the cisterna chyli by retaining fluid during operation of the implantable thoracic duct pump device, thereby smoothing out small variations in pressure that may arise in the bench test setup. A pressure sensor (or pressure transducer) is placed in line downstream of the seal of the implantable thoracic duct pump device to measure the pressure of the system during operation of the implantable thoracic duct pump device.

[0152] Upstream of the implantable thoracic duct pump device is a second reservoir representing the venous system. The volume of fluid in the second reservoir is selected to as to approximate the venous blood pressure of a patient. The second reservoir includes an overflow point so that additional fluid supplied by the implantable thoracic duct pump device may flow out of the reservoir without altering the backing pressure on the implantable thoracic duct pump device.

[0153] In this regard, FIG. 13B provides a block diagram depicting the connection of components in the bench test setup described with respect to FIG. 16A. In this flow diagram, a reservoir provides a source of fluid for a first pump, which provides fluid to the cisterna chyli, and to a second pump, which helps draw fluid out through the 3915-P1359WO.UW -26-implantable thoracic duct pump device and back into the reservoir. Data acquisition from the pressure transducer allows for a measurement of the internal pressure.

[0154] FIG. 13C and FIG. 13D depict the testing setup of a duct seal of the implantable thoracic duct pump device described in FIG. 13A. FIG. 13C depicts a side view, which highlights the two legs configured to represent the junction between the left subclavian and the right jugular vein within which the duct seal is configured to be placed. FIG. 13D depicts a top view of the testing setup, and in this regard demonstrates the thoracic duct emerging from where the left subclavian and the jugular vein meet.

[0155] In FIG. 14A, an example is depicted of a theoretical curve for the bench test setup of FIG.13A. In step one, the first pump operates at a rate faster than the second pump. In this regard, fluid is introduced into the bladder at a faster rather than it is drawn out through the implantable thoracic duct pump device that the second pump is part of. The pressure readings gradually build. In step two, the second pump is ramped up to maintain a steady 1.5 mV pressure reading from the pressure transducer. Subsequently, at step three, the second pump is now at a faster rate than the first pump, representing lymphatic fluid mobilization, and the pressure measured by the pressure transducer decreases. Finally, at step four, the second pump matches the rate of the first pump to maintain the reduced pressure within the fluid system.

[0156] As can be seen starting at Step 1 and Step 3, the creation of a pressure differential between the first and second pumps promotes an increase or decrease in the overall pressure of the system as measured by the pressure transducer. Similarly, at Step 2 and Step 4, the pressure remains relatively constant, as the input and output pump operations cancel one another out. An analysis of the curve dynamics therefore allows for diagnosing the sealing efficiency of the duct seal of the implantable thoracic duct pump device.

[0157] In this regard, FIG. 14B - FIG.14E depicts theoretical curves for various scenarios in the bench test experiment. FIG.14B provides a theoretical curve highlighting the shape when the seal and pump are both operating properly and efficiently.

[0158] FIG. 14C depicts a scenario where there is a leak within the lymphatic model system, such that when the pumps are both running at the same rate, the pressure is decreasing because fluid is leaking out. Under these conditions, adjustments need to be made to the model system to avoid leaks. 3915-P1359WO.UW -27-

[0159] FIG. 14D depicts a scenario where the second pump is improperly weak or where there is an inefficient duct seal because in both cases, the reduction in pressure is slowed. As can be seen in the theoretical curve, at both the matching and pressure relief stages, the weak pump prevents the system from properly matching the pressure of pump 1, thus leading to an insufficiently flat seal retention portion, as well as a longer draw-down rate when the pressure of pump 1 is decreased at Step 3.

[0160] Conversely, FIG. 14E depicts a scenario where the second pump is improperly overpowered. Thus, at Step 2 the pressure in the system begins to decrease as the pump operations are theoretically matched. However, at Step 3, the overpowered pump will result in an accelerated drop in pressure.

[0161] In accordance with the above theoretical curves, FIG.15 depicts a test of an implantable thoracic duct pump device in the bench test setup of FIG. 13A- FIG. 13D, where only an internal intraductal seal is implemented. As can be seen from the shape of the curve between positions 1 and 2, and positions 2 and 3, when the pumps are either both off or both on and operating at 30 rpm, a proper seal is indicated by virtue of the flat shape of the curve. Between positions 3 and 4, the pressure of the first pump is decreased relative to the second pump, resulting in a gradual decrease in pressure of the system. Once the operating rate of the first and second pumps is equalized again at position 4, the pressure of the system once more reaches equilibrium. The linear and robust decrease in pressure between position 3 and position 4 represents the very high efficiency of the intraductal seal with no evidence of leak around the seal, even allowing the generation of negative pressure within the system.

[0162] Along similar lines, FIG.16 depicts a bench test of an implantable thoracic duct pump device in the bench test setup of FIG. 13A - FIG. 13D, where only an external venous seal is implemented without a seal within the duct itself. As can be seen from the shape of the curves, the external venous seal alone provides more variability of pressure over time. Between positions 1 and 2, both pumps are off, demonstrating a comparable background pressure condition. At position 2, both pumps are turned on; despite the matching of operating rate of the first and second pumps, the overall pressure in the system begins to rise as the pump attached to the external seal is not able to as efficiently remove fluid compared to the rate that it is being added to the system. Further, at position 3, when the operating rate of the second pump is greater than that of the first pump, the overall pressure of the system begins to slowly decrease yet at a much slower rate and with less 3915-P1359WO.UW -28-consistency. Taken together, this demonstrates that the external seal approach is still able to reduce the pressure within the lymphatic model system, but that efficiency is lost in the setting that the seal is not tightly affixed. Thus, this demonstrates how the design and contour of the external seal along the venous wall may strongly influence the effectiveness of the system.

[0163] The detailed description set forth above in connection with the appended drawings, where like numerals reference like elements, are intended as a description of various embodiments of the present disclosure and are not intended to represent the only embodiments. Each embodiment described in this disclosure is provided as a representative example or illustration and should not be construed as preferred or advantageous over other embodiments. The representative examples provided herein are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Similarly, any steps described herein may be interchangeable with other steps, or combinations of steps, in order to achieve the same or substantially similar result. Generally, the embodiments disclosed herein are non-limiting, and the inventors contemplate that other embodiments within the scope of this disclosure may include structures and functionalities from more than one specific embodiment shown in the figures and described in the specification. That is, the present disclosure includes embodiments that combine features from different embodiments.

[0164] In the foregoing description, specific details are set forth to provide a thorough understanding of exemplary embodiments of the present disclosure. It will be apparent to one skilled in the art, however, that the embodiments disclosed herein may be practiced without embodying all the specific details. In some instances, well-known process steps have not been described in detail in order not to unnecessarily obscure various aspects of the present disclosure. Further, it will be appreciated that embodiments of the present disclosure may employ any combination of features described herein.

[0165] In the detailed description herein, references to "one embodiment", "an embodiment", "an example embodiment", "one or more embodiments, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one 3915-P1359WO.UW -29-skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments. Thus, it will be appreciated that embodiments of the present disclosure may employ any combination of features described herein. All such combinations or sub- combinations of features are within the scope of the present disclosure.

[0166] Throughout this specification, terms of art may be used. These terms are to take on their ordinary meaning in the art from which they come, unless specifically defined herein or the context of their use would clearly suggest otherwise.

[0167] The drawings in the FIGURES are not to scale. Similar elements are generally denoted by similar references in the FIGURES. For the purposes of this disclosure, the same or similar elements may bear the same references. Furthermore, the presence of reference numbers or letters in the drawings cannot be considered limiting, even when such numbers or letters are indicated in the claims.

[0168] In the claims and for purposes of the present disclosure, the terms "a", "an", "the", and the like, refer to the singular and the plural forms of the object or element referenced.

[0169] The present application may include references to directions, such as "vertical," "horizontal," "front," "rear," "left," "right," "top," and "bottom," etc. These references, and other similar references in the present application, are intended to assist in helping describe and understand the particular embodiment (such as when the embodiment is positioned for use) and are not intended to limit the present disclosure to these directions or locations.

[0170] The present application may also reference quantities and numbers. Unless specifically stated, such quantities and numbers are not to be considered restrictive, but exemplary of the possible quantities or numbers associated with the present application. Also in this regard, the present application may use the term "plurality" to reference a quantity or number. In this regard, the term "plurality" is meant to be any number that is more than one, for example, two, three, four, five, etc. The term "about," "approximately," etc., means plus or minus 5% of the stated value. The term "based upon" means "based at least partially upon."

[0171] The principles, representative embodiments, and modes of operation of the present disclosure have been described in the foregoing description. However, aspects 3915-P1359WO.UW -30-of the present disclosure, which are intended to be protected, are not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. It will be appreciated that variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present disclosure. Accordingly, it is expressly intended that all such variations, changes, and equivalents fall within the spirit and scope of the present disclosure as claimed. EMBODIMENTS

[0172] While general features of the disclosure are described and shown and particular features of the disclosure are set forth in the claims, the following non-limiting embodiments relate to features, and combinations of features, that are explicitly envisioned as being part of the disclosure. The following non-limiting embodiments contain elements that are modular and can be combined with each other in any number, order, or combination to form a new non-limiting embodiment, which can itself be further combined with other non-limiting embodiments.

[0173] Embodiment 1. An implantable thoracic duct pump device comprising: a fluid micropump including a motor inlet and a motor outlet; a thoracic duct cannula in fluid communication with the motor inlet; and a duct seal surrounding an exterior of the thoracic duct cannula and configured to form a seal at an outlet of a thoracic duct, wherein the duct seal is sized and shaped to seal an ostium of the thoracic duct when the thoracic duct cannula of the implantable thoracic duct pump device is implanted in the thoracic duct of a subject.

[0174] Embodiment 2. The implantable thoracic duct pump device of Embodiment 1, further including a duct-cannula retainer.

[0175] Embodiment 3. The implantable thoracic duct pump device of Embodiments 1 or 2, wherein the duct-cannula retainer includes a sealing balloon.

[0176] Embodiment 4. The implantable thoracic duct pump device of any of the previous Embodiments, further comprising a sleeve positioned on an exterior of the duct- cannula retainer and configured to retain the duct-cannula retainer in a stationary configuration within the thoracic duct.

[0177] Embodiment 5. The implantable thoracic duct pump device of any of the previous Embodiments, wherein the sleeve comprises a sleeve texture configured to provide friction with an internal lumen of the thoracic duct. 3915-P1359WO.UW -31-

[0178] Embodiment 6. The implantable thoracic duct pump device of any of the previous Embodiments, wherein the duct seal inclues a contoured sealing ring.

[0179] Embodiment 7. The implantable thoracic duct pump device of any of the previous Embodiments, wherein the duct seal includes a flange that lays along the vein wall immediately adjacent to the thoracic duct ostium, such that it can facilitate pressure reduction of the lymphatic system beginning immediately at the terminal thoracic duct ostium without blocking lymphatic channels that connect towards the end of the terminal thoracic duct.

[0180] Embodiment 8. The implantable thoracic duct pump device of any of the previous Embodiments, further comprising a lumen adjacent to the contoured sealing ring, wherein the lumen is sized and shaped to promote lymphatic flow from small lymphatic vessels that fluidly connect to a terminal end of the thoracic duct through the implantable thoracic duct pump device.

[0181] Embodiment 9. The implantable thoracic duct pump device of any of the previous Embodiments, further comprising a power supply cable connected to the fluid micropump, wherein the power supply cable is in electrical communication with a power source.

[0182] Embodiment 10. The implantable thoracic duct pump device of any of the previous Embodiments, wherein the power source is a battery sized and shaped for subcutaneous implantation.

[0183] Embodiment 11. The implantable thoracic duct pump device of any of the previous Embodiments, wherein the duct seal comprises two or more tack points configured to be embedded in a vein of a subject.

[0184] Embodiment 12. The implantable thoracic duct pump device of any of the previous Embodiments, wherein the duct seal comprises two or more external braces comprising a first brace side and a second brace side, wherein the first brace side is coupled to the duct seal, and wherein the second brace side is configured to contact a portion of a vein of a subject.

[0185] Embodiment 13. The implantable thoracic duct pump device of any of the previous Embodiments, wherein the thoracic duct cannula includes a first inlet and a second inlet.

[0186] Embodiment 14. The implantable thoracic duct pump device of any of the previous Embodiments, wherein the first inlet is at a distal end of the thoracic duct cannula. 3915-P1359WO.UW -32-

[0187] Embodiment 15. The implantable thoracic duct pump device of any of the previous Embodiments, wherein the second inlet is defined along a wall of the thoracic duct cannula.

[0188] Embodiment 16. The implantable thoracic duct pump device of any of the previous Embodiments, wherein the second inlet comprises a plurality of perforations in the wall of the thoracic duct cannula configured to allow lymphatics from both the thoracic duct and from lymphatic side channels of the thoracic duct to enter the thoracic duct cannula.

[0189] Embodiment 17. A method of alleviating diuretic refractory fluid overload, the method comprising: providing an implantable thoracic duct pump device external to the thoracic duct outlet within a venous system of a subject, wherein the implantable thoracic duct pump comprises: a fluid micropump comprising a motor inlet and a motor outlet wherein the motor outlet is located at a junction of a left subclavian vein and an internal jugular vein of the venous system of the subject; a thoracic duct cannula in fluid communication with the motor inlet; and a duct seal surrounding an exterior of the thoracic duct cannula and configured to form a seal in a thoracic duct, wherein the duct seal is sized and shaped to seal the ostium at an outlet of the thoracic duct when the implantable thoracic duct pump device is implanted in the thoracic duct of a subject; and generating a pressure differential between the venous system and the thoracic duct of the subject, thereby facilitating lymphatic flow into the venous system.

[0190] Embodiment 18. The method of Embodiment 17, wherein the implantable thoracic duct pump device further comprises a duct-cannula retainer.

[0191] Embodiment 19. The method of any of Embodiments 17 or 18, wherein the implantable thoracic duct pump device further comprises a sleeve positioned on an exterior of the duct-cannula retainer and configured to retain the duct-cannula retainer in a stationary configuration within the thoracic duct.

[0192] Embodiment 20. The method of any of Embodiments 17-19, wherein the duct-cannula retainer comprises a sealing balloon.

[0193] Embodiment 21. The method of any of Embodiments 17-20, wherein the duct seal comprises a contoured sealing ring configured to seal an ostium of the thoracic duct.

[0194] Embodiment 22. The method of any of Embodiments 17-21, wherein the duct seal comprises a flange that is sized and shaped to lay along a vein wall immediately 3915-P1359WO.UW -33-adjacent to the thoracic duct ostium, such that it can facilitate pressure reduction of the lymphatic system beginning immediately at the terminal thoracic duct ostium without blocking lymphatic channels that connect towards the end of the terminal thoracic duct.

[0195] Embodiment 23. The method of any of Embodiments 17-22, wherein the implantable thoracic duct pump device further comprises a lumen adjacent to the contoured sealing ring, wherein the lumen is sized and shaped to promote lymphatic flow from small lymphatic vessels that fluidly connect to the terminal thoracic duct.

[0196] Embodiment 24. The method of any of Embodiments 17-21, further comprising the step of supplying electric power to the fluid micropump via a power supply cable in the venous system, wherein the power supply cable is in electrical communication with a power source.

[0197] Embodiment 25. The method of any of Embodiments 17-22, wherein the power source is a battery sized and shaped for subcutaneous implantation.

[0198] Embodiment 26. The method of any of Embodiments 17-25, wherein the duct seal comprises two or more tack points configured to be embedded in a vein of a subject.

[0199] Embodiment 27. The method of any of Embodiments 17-26, wherein the duct seal comprises two or more external braces comprising a first brace side and a second brace side, wherein the first brace side is coupled to the duct seal, and wherein the second brace side is configured to contact a portion of a vein of a subject.

[0200] Embodiment 28. The method of any of Embodiments 17-27, wherein the thoracic duct cannula comprises a first inlet and a second inlet.

[0201] Embodiment 29. The method of any of Embodiments 17-28, wherein the first inlet is at a distal end of the thoracic duct cannula.

[0202] Embodiment 30. The method of any of Embodiments 17-29, wherein the second inlet is defined along a wall of the thoracic duct cannula.

[0203] Embodiment 31. The method of any of Embodiments 17-30, wherein the second inlet comprises a plurality of lumens in the wall of the thoracic duct cannula configured to draw lymphatics from both the thoracic duct and from lymphatic side channels of the thoracic duct.

[0204] Embodiment 32. A method of implanting an implantable thoracic duct pump device, the method including: accessing a left thoracic duct via a percutaneous transcervical approach; accessing a right subclavian vein via micropuncture access; 3915-P1359WO.UW -34-inserting a first guide wire and a guide catheter into the right subclavian vein; inserting a second guide wire into the right subclavian vein via the left thoracic duct; inserting a catheter over the second guide wire; inserting a snare into a brachiocephalic vein; snaring the second guide wire with the snare; drawing the second guide wire out through the right subclavian vein by pulling on the snare; inserting the implantable thoracic duct pump device into the right subclavian vein along the first guide wire; advancing the implantable thoracic duct pump device into a flush seal against the ostium of the thoracic duct; and wherein the implantable thoracic duct pump device includes: a fluid micropump sized and shaped to be implanted in a vein adjacent to the thoracic duct ostium, the fluid micropump including a motor inlet and a motor outlet; a thoracic duct cannula in fluid communication with the motor inlet; and a duct seal surrounding an exterior of the thoracic duct cannula and configured to form a seal in a thoracic duct, wherein the duct seal is sized and shaped to seal the ostium of the thoracic duct when the implantable thoracic duct pump device is implanted in the thoracic duct of a subject.

[0205] While illustrative embodiments have been illustrated and described, it will be that various changes can be made therein without departing from the spirit and scope of the invention. 3915-P1359WO.UW -35-

Claims

CLAIMS The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An implantable thoracic duct pump device comprising: a fluid micropump comprising a motor inlet and a motor outlet; a thoracic duct cannula in fluid communication with the motor inlet; and a duct seal surrounding an exterior of the thoracic duct cannula and configured to form a seal at an outlet of a thoracic duct, wherein the duct seal is sized and shaped to seal an ostium of the thoracic duct when the thoracic duct cannula of the implantable thoracic duct pump device is implanted in the thoracic duct of a subject.

2. The implantable thoracic duct pump device of claim 1, further comprising a duct-cannula retainer.

3. The implantable thoracic duct pump device of claim 2, wherein the duct- cannula retainer comprises a sealing balloon.

4. The implantable thoracic duct pump device of claim 2, further comprising a sleeve positioned on an exterior of the duct-cannula retainer configured to retain the duct- cannula retainer in a stationary configuration within the thoracic duct.

5. The implantable thoracic duct pump device of claim 3, wherein the sleeve comprises a sleeve texture configured to provide friction with an internal lumen of the thoracic duct.

6. The implantable thoracic duct pump device of claim 1, wherein the duct seal comprises a contoured sealing ring.

7. The implantable thoracic duct pump device of claim 6, wherein the duct seal comprises a flange that is sized and shaped to lay along a vein wall immediately adjacent to the thoracic duct ostium, such that it can facilitate pressure reduction of the lymphatic system beginning immediately at the terminal thoracic duct ostium without blocking lymphatic channels that connect towards the end of the terminal thoracic duct. 3915-P1359WO.UW -36-8. The implantable thoracic duct pump device of claim 6, further comprising a lumen adjacent to the contoured sealing ring, wherein the lumen is sized and shaped to promote lymphatic flow from small lymphatic vessels that fluidly connect to a terminal end of the thoracic duct through the implantable thoracic duct pump device.

9. The implantable thoracic duct pump device of claim 1, further comprising a power supply cable connected to the fluid micropump, wherein the power supply cable is in electrical communication with a power source.

10. The implantable thoracic duct pump device of claim 9, wherein the power source is a battery sized and shaped for subcutaneous implantation.

11. The implantable thoracic duct pump device of claim 1, wherein the duct seal comprises two or more tack points configured to be embedded in a vein of the subject.

12. The implantable thoracic duct pump device of claim 1, wherein the duct seal comprises two or more external braces comprising a first brace side and a second brace side, wherein the first brace side is coupled to the duct seal, and wherein the second brace side is configured to contact a portion of a vein of the subject.

13. The implantable thoracic duct pump device of claim 1, wherein the thoracic duct cannula comprises a first inlet and a second inlet.

14. The implantable thoracic duct pump device of claim 13, wherein the first inlet is at a distal end of the thoracic duct cannula.

15. The implantable thoracic duct pump device of claim 13, wherein the second inlet is defined along a wall of the thoracic duct cannula.

16. The implantable thoracic duct pump device of claim 13, wherein the second inlet comprises a plurality of perforations in the wall of the thoracic duct cannula configured to allow lymphatics from both the thoracic duct and from lymphatic side channels of the thoracic duct enter the thoracic duct cannula.

17. A method of alleviating diuretic refractory fluid overload, the method comprising: 3915-P1359WO.UW -37-providing an implantable thoracic duct pump device external to the thoracic duct outlet within a venous system of a subject, wherein the implantable thoracic duct pump comprises: a fluid micropump comprising a motor inlet and a motor outlet wherein the motor outlet is located at a junction of a left subclavian vein and an internal jugular vein of the venous system of the subject; a thoracic duct cannula in fluid communication with the motor inlet; and a duct seal surrounding an exterior of the thoracic duct cannula that forms a seal in a thoracic duct, wherein the duct seal is sized and shaped to seal the ostium at an outlet of the thoracic duct when the thoracic duct cannula of the implantable thoracic duct pump device is implanted in the thoracic duct of the subject; and generating a pressure differential between the venous system and the thoracic duct of the subject, thereby facilitating lymphatic flow into the venous system.

18. The method of claim 17, wherein the implantable thoracic duct pump device further comprises a duct-cannula retainer.

19. The method of claim 17, wherein the implantable thoracic duct pump device further comprises a sleeve positioned on an exterior of the duct-cannula retainer that is retained in a stationary configuration within the thoracic duct.

20. The method of claim 17, wherein the duct-cannula retainer comprises a sealing balloon.

21. The method of claim 17, wherein the duct seal comprises a contoured sealing ring that seals an ostium of the thoracic duct.

22. The method of claim 21, wherein the duct seal comprises a flange that is sized and shaped to lay along a vein wall immediately adjacent to the thoracic duct ostium, such that it can facilitate pressure reduction of the lymphatic system beginning immediately at the terminal thoracic duct ostium without blocking lymphatic channels that connect towards the end of the terminal thoracic duct.

23. The method of claim 21, wherein the implantable thoracic duct pump device further comprises a lumen adjacent to the contoured sealing ring, wherein the lumen is 3915-P1359WO.UW -38-sized and shaped to promote lymphatic flow from small lymphatic vessels that fluidly connect to the terminal thoracic duct.

24. The method of claim 17, further comprising the step of supplying electric power to the fluid micropump via a power supply cable in the venous system, wherein the power supply cable is in electrical communication with a power source.

25. The method of claim 24, wherein the power source is subcutaneously implanted.

26. The method of claim 17, wherein the duct seal comprises two or more tack points embedded in a vein of the subject.

27. The method of claim 17, wherein the duct seal comprises two or more external braces comprising a first brace side and a second brace side, wherein the first brace side is coupled to the duct seal, and wherein the second brace side contacts a portion of a vein of the subject.

28. The method of claim 17, wherein the thoracic duct cannula comprises a first inlet and a second inlet.

29. The method of claim 17, wherein the first inlet is at a distal end of the thoracic duct cannula.

30. The method of claim 17, wherein the second inlet is defined along a wall of the thoracic duct cannula.

31. The method of claim 17, wherein the second inlet comprises a plurality of lumens in the wall of the thoracic duct cannula draws lymphatics from both the thoracic duct and from lymphatic side channels of the thoracic duct.

32. A method of implanting an implantable thoracic duct pump device, the method comprising: accessing a left thoracic duct via a percutaneous transcervical approach; accessing a right subclavian vein via micropuncture access; inserting a first guide wire and a guide catheter into the right subclavian vein; 3915-P1359WO.UW -39-inserting a second guide wire into the left brachiocephalic vein via the left thoracic duct; inserting a catheter over the second guide wire; inserting a snare into a brachiocephalic vein; snaring the second guide wire with the snare; drawing the second guide wire out through the right subclavian vein by pulling on the snare; inserting the implantable thoracic duct pump device into the right subclavian vein along the second guide wire that connects the thoracic duct to the right subclavian vein; and advancing the implantable thoracic duct pump device into a flush seal against the ostium of the thoracic duct; wherein the implantable thoracic duct pump device comprises: a fluid micropump sized and shaped to be implanted in a vein adjacent to the thoracic duct ostium, the fluid micropump comprising a motor inlet and a motor outlet; a thoracic duct cannula in fluid communication with the motor inlet; and a duct seal surrounding an exterior of the thoracic duct cannula and configured to form a seal in a thoracic duct, wherein the duct seal is sized and shaped to seal the ostium of the thoracic duct when the implantable thoracic duct pump device is implanted in the thoracic duct of a subject. 3915-P1359WO.UW -40-

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