Dual lumen cannula devices and methods

Abstract

Cannula devices can be used for withdrawing venous blood from a patient and returning arterial blood to the patient after extracorporeal oxygenation. For example, this document describes dual lumen cannula devices and methods for their use with systems such as extracorporeal membrane oxygenation (ECMO) systems. The technology described herein includes a cannula device, and a methodology utilizing the cannula device, to provide complete hemodynamic support incorporating both venous drainage cannula and arterial return cannula in a single cannula device.

Description

[0001] DUAL LUMEN CANNULA DEVICES AND METHODS

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 525,833, filed July 10, 2023. The disclosure of the prior application is considered part of the disclosure of this application, and is incorporated in its entirety into this application.

[0004] BACKGROUND

[0005] 1. Technical Field

[0006] This document relates to cannula devices for withdrawing venous blood from a patient and returning arterial blood to the patient after extracorporeal oxygenation. For example, this document relates to dual lumen cannula devices and methods for their use with systems such as extracorporeal membrane oxygenation systems.

[0007] 2. Background Information

[0008] In refractory cases of cardiogenic shock, including post-cardiotomy shock and cardiogenic shock due to decompensated heart failure or acute myocardial infarction, venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been increasingly utilized. Presently, there are two primary modalities for achieving VA- ECMO support: central cannulation and peripheral cannulation. In the former modality, a surgical sternotomy is utilized to cannulate the right atrium for venous outflow (i.e., drainage) towards the oxygenator and to cannulate the ascending aorta for return of oxygenated blood from the oxygenator and pump circuit.

[0009] The absolute requirement for anticoagulation, which can result in profound bleeding, and the significantly invasive nature of this methodology limit its applicability. In contrast, peripheral VA-ECMO is achieved by placing the cannulae in the femoral vein and femoral artery to achieve oxygenation with the femoral vein serving as the drainage cannula and femoral artery as the return cannula However, this technique is limited by several complications, including (1) the risk of rupture of the femoral vessels at the time of access, (2) distal limb ischemia, and (3) risk of hemorrhage. Additionally, because oxygenated blood perfuses the head "retrograde" from the femoral artery, competing blood flow ejected by the left ventricle (often low on oxygen if lungs are failing), may cause cerebral hypoxia in a syndrome referred to as Harlequin Syndrome. The region of competing VA-ECMO retrograde flow and hypoxemic antegrade flow is referred to as a mixing cloud.

[0010] SUMMARY

[0011] This document describes cannula devices for withdrawing venous blood from a patient and returning arterial blood to the patient after extracorporeal oxygenation. For example, this document describes dual lumen cannula devices and methods for their use with systems such as extracorporeal membrane oxygenation systems.

[0012] In one aspect, this disclosure is directed to a cannula that includes a proximal portion defining an arterial lumen and a venous lumen that is fluidly distinct from the arterial lumen; a distal portion defining the arterial lumen; and a middle portion extending between the proximal and distal portions. The middle portion defines the arterial and venous lumens. The venous lumen terminates at a distal end of the middle portion.

[0013] Such a cannula may optionally include one or more of the following features. The proximal portion may also define a plurality of first elongate openings through a wall portion of the proximal portion that defines the venous lumen. The middle portion may also define a plurality of second elongate openings through a wall portion of the middle portion that defines the venous lumen. The distal portion may also define a plurality of third elongate openings through a wall portion of the distal portion that defines the arterial lumen. In some embodiments, an open area of each first elongate opening of the plurality of first elongate openings is larger than an open area of each second elongate opening of the plurality of second elongate openings. The first elongate openings may extend along spiral paths around a central longitudinal axis of the proximal portion. In some embodiments, an outer diameter of the middle portion is smaller than an outer diameter of the proximal portion. In some embodiments, an outer diameter of the distal portion is smaller than the outer diameter of the middle portion. A cross-sectional area of the venous lumen of the proximal portion may be larger than a cross-sectional area of the arterial lumen of the proximal portion. The proximal portion may comprise a tubular outer wall and an inner wall that separates the arterial lumen from the venous lumen. In some embodiments, a cross-sectional shape of the tubular outer wall is a circle and a cross-section of the inner wall extends along a chord of the circle. In some embodiments, the chord does not intersect a center of the circle. The arterial and venous lumens of the proximal portion may spiral around each other along a longitudinal length of the proximal portion.

[0014] In another aspect, this disclosure is directed to a method of treating a patient. The method includes inserting a cannula into a femoral vein of the patient and advancing the cannula to a heart of the patient. The cannula comprises: (i) a proximal portion defining an arterial lumen and a venous lumen that is fluidly distinct from the arterial lumen; (ii) a distal portion defining the arterial lumen; and (iii) a middle portion extending between the proximal and distal portions. The middle portion defines the arterial and venous lumens. The venous lumen terminates at a distal end of the middle portion. When the cannula is inserted into the femoral vein and the heart, the proximal portion resides in an inferior vena cava and right atrium of the patient, the middle portion crosses an atrial septum and resides in a left atrium of the patient, and the distal portion extends from a left ventricle and into an ascending aorta of the patient.

[0015] Such a method may optionally include one or more of the following features. The method may also include drawing venous blood of the patient into the venous lumen of the cannula from: (i) the inferior vena cava, (ii) the right atrium, and (iii) the left atrium. The method may also include supplying arterial blood to the aorta of the patient via the arterial lumen and the distal portion of the cannula. In some embodiments, the venous blood and blood from a left atrium, simultaneously drawn from the patient, is oxygenated outside of the patient’s body and then returned to the aorta of the patient via the arterial lumen of the cannula.

[0016] In another aspect, this disclosure is directed to another method of threating a patient. The method includes inserting a cannula into a jugular vein of the patient and advancing the cannula to a heart of the patient. The cannula includes: (i) a proximal portion defining an arterial lumen and a venous lumen that is fluidly distinct from the arterial lumen; (ii) a distal portion defining the arterial lumen; and (iii) a middle portion extending between the proximal and distal portions. The middle portion defines the arterial and venous lumens. The venous lumen terminates at a distal end of the middle portion. The proximal portion resides in a superior vena cava and right atrium of the patient. The middle portion crosses an atrial septum and resides in a left atrium of the patient. The distal portion extends from a left ventricle and into an aorta of the patient. Such a method may optionally include one or more of the following features. The method may also include drawing venous blood of the patient into the venous lumen of the cannula from: (i) the superior vena cava, (ii) the right atrium, and (lii) the left atrium. The method may also include supplying arterial blood to the aorta of the patient via the arterial lumen and the distal portion of the cannula, wherein the venous blood drawn from the patient is oxygenated outside of the patient's body and then returned to the aorta of the patient via the arterial lumen of the cannula.

[0017] Particular embodiments of the subject matter described in this document can be implemented to realize one or more of the following advantages. Currently available dual lumen cannulae cannot be used to provide complete hemodynamic support analogous to that of VA-ECMO because they are designed only for right ventricular support. Those cannulae do not provide outflow into the aorta, as they have neither the length nor the design features for left atrial (LA) venting. As described further below, the dual lumen cannulae described herein solve such shortcomings of present dual lumen cannulae. The precise diameters of the dual lumen cannula described herein provide optimal flow for drainage of the respective chambers and arterial supply outflow to the aorta. No currently available cannula device is designed for venous only cannulation and aortic outflow in a single device, minimizing the risk of large bore vessel cannulation. The unique serpiginous nature of the drainage and return portions of the dual lumen cannula described herein advantageously provide maximal flow while minimizing the cannula diameter. Lastly, the devices and methods described herein, although technically a “peripheral’’ cannulation technique, advantageously avoid any peripheral arterial cannulation, which is associated with hemorrhagic risk, while at the same time avoids the risk of Harlequin syndrome as the aortic outflow provides anterograde flow, analogous to “central” cannulation. Moreover, the dual lumen cannulae described herein are adaptable for placement both from the femoral vein and the internal jugular veins, maximizing its utility in practice.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described herein. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

[0019] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description herein. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

[0020] DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a cut-away view of a heart and an example dual lumen cannula device in accordance with some embodiments provided herein.

[0022] FIG. 2 is another cut-away view of the heart and dual lumen cannula device of FIG. 1.

[0023] FIG. 3 shows various views of a transition portion of the dual lumen cannula device of FIG. 1.

[0024] FIG. 4 shows various views of a distal portion of the dual lumen cannula device of FIG. 1 .

[0025] FIG. 5 shows a portion of the dual lumen cannula device of FIG. 1.

[0026] FIG. 6 shows an example of jugular vein access with the dual lumen cannula devices described herein to provide perfusion to a heart region of a patient.

[0027] Like reference numbers represent corresponding parts throughout.

[0028] DETAILED DESCRIPTION

[0029] This document describes cannula devices for withdrawing venous blood from a patient and returning arterial blood to the patient after extracorporeal oxygenation. For example, this document describes dual lumen cannula devices and methods for their use with systems such as extracorporeal membrane oxygenation systems.

[0030] The technology described herein includes a cannula device, and a methodology utilizing the cannula device, to provide complete hemodynamic support incorporating both venous drainage cannula and arterial return cannula in a single cannula device.

[0031] FIGs. 1-4 show an example cannula 100 in place within a heart H. In this particular arrangement, the cannula 100 extends to the heart H through the inferior vena cava IVC (e.g., from a femoral vein and an external iliac vein). From the inferior vena cava IVC, the cannula 100 enters a right atrium RA of the heart H and passes through an opening made in an atrial septum AS of the heart H. The cannula 100 then extends into a left atrium LA, crosses a mitral valve MV, and extends into a left ventricle LV of the heart H. In the left ventricle LV, the cannula 100 turns and crosses the aortic valve AV. After crossing the aortic valve AV, the cannula 100 extends into the aorta AO. The distal tip of the cannula 100 terminates in the aorta AO. This arrangement can be used for VA-ECMO support, for example, as described further below.

[0032] The cannula 100 includes a proximal portion 110, a middle portion 120, and a distal portion 130. The middle portion 120 extends between the proximal portion 110 and the distal portion 130. The distal portion 130 terminates at a distal tip of the cannula 100.

[0033] When positioned in a patient as shown in FIGs. 1 and 2, the proximal portion 110 resides in the inferior vena cava IVC and the right atrium RA. The middle portion 120 passes through the atrial septum AS and resides in the left atrium LA. The distal portion 130 extends through the left ventricle LV, crosses the aortic valve AV, and extends into the aorta AO.

[0034] As visible in FIG. 3, the proximal portion 110 defines two separate and fluidly distinct lumens that can convey blood. The two lumens are a venous lumen 111 and an arterial lumen 112. The venous lumen 111 is used for conveying oxy gen-depleted blood away from the patient to an extracorporeal oxygenation system positioned external to the patient. The arterial lumen 112 is used for conveying oxygen-rich blood from the extracorporeal oxygenation system back to the patient to be circulated to all portions of the patient's body.

[0035] It can be seen in the cross-sectional view of FIG. 3 that the proximal portion 110 has a tubular outer wall 113 (which is circular in cross-section) and an inner wall 114 that separates the venous lumen 111 from the arterial lumen 112. In geometric terms, the inner wall 114 extends along a chord of the circular tubular outer wall 113. The inner wall 114 does not pass through a center of the circular tubular outer wall 113 of the proximal portion 110. The length of the inner wall 114 is less than a diameter of the circular tubular outer wall 113. Accordingly, at least in the proximal portion 110, the venous lumen 111 and the arterial lumen 112 have differing cross- sectional areas. In the depicted embodiment, the venous lumen 111 has a larger cross-sectional area than the arterial lumen 112. In some embodiments, the ratio of the cross- sectional areas of the venous lumen 111 to the arterial lumen ranges from 2: 1 to 2: 1.5, or from 2:0.5 to 2:1.2, or from 2:0.2 to 2:0.8, or from 2:1.4 to 2:1.9, without limitation.

[0036] The proximal portion 110 defines a plurality of elongated openings 115 (e.g., fenestrations, windows, slits, slots, channel openings, oval shaped openings, etc.) that extends through the tubular wall 1 13 of the proximal portion 1 10 and into the venous lumen 111. These elongated shapes can extend either vertically (as depicted) and / or horizontally, or a mixture of both, or at an acute angle between vertical and horizontal across a length of the cannula 100 at the proximal portions 110 and the middle portion 120. The elongate shape of the openings 1 15 helps to reduce shear stress on the blood as it passes through the openings 115 leading to the venous lumen 111. The openings 115 allow venous blood from the patient’s inferior vena cava IVC and right atrium RA to enter into the venous lumen 111. However, none of the openings 115 extends through the inner wall 114 of the proximal portion 1 10 and into the arterial lumen 1 12. Instead, the arterial lumen 112 is a fully continuously sealed lumen within the proximal portion 110.

[0037] In FIG. 3, a transition portion 116 is visible. The transition portion 116 connects a distal end of the proximal portion 110 with a proximal end of the middle portion 120. The transition portion 116 reduces in diameter from a larger diameter of the proximal portion 110 to a smaller diameter of the middle portion 120. In some non- limiting example embodiments, the transition portion 116 reduces from 30 Fr. of the proximal portion 110 to 20 Fr. of the middle portion 120, or reduces by some other suitable size reduction extent. As shown in FIG. 2, the transition portion 116 is positioned in the right atrium RA just prior to the arterial septum AS. Accordingly, an opening made in the atrial septum AS can be smaller (e.g, the smaller diameter of the middle portion 120 rather than the larger diameter of the proximal portion 110).

[0038] As visible in FIG. 3, the inner wall 114 continues from the proximal portion 110, through the transition portion 116, and into the middle portion 120. Accordingly, the middle portion 120 includes both the venous lumen 111 and the arterial lumen 112. The venous lumen 111 and the arterial lumen 112 are maintained as separate fluidly distinct lumens throughout the length of the middle portion 120, until the distal end of the middle portion 120. In FIGs. 1 and 3, the middle portion 120 defines a plurality of elongate openings 125 (e.g.. fenestrations, windows, slits, slots, channel openings, etc.) that extend through a tubular wall of the middle portion 120 and into the venous lumen 111. The openings 125 allow blood from the left atrium LA of the patient to enter the venous lumen 111 (z.e., LV venting). However, none of the openings 125 extends through the wall of the middle portion 120 and into the arterial lumen 112. Instead, the arterial lumen 112 is a fully continuously sealed lumen within the middle portion 120 and the proximal portion 110.

[0039] At the distal end of the middle portion 120, the venous lumen 111 of the proximal portion 110 and the middle portion 120 terminates. However, the arterial lumen 112 continues into the distal portion 130. In other words, the proximal portion 110 and the middle portion 120 are dual lumen cannulae, but the distal portion 130 is a single lumen cannula (with that single lumen being the arterial lumen 112). Accordingly, the size of the cannula 100 reduces at the transition from the middle portion 120 to the distal portion 130. In some example embodiments, the distal portion 130 is a 14 Fr. or 15 Fr. cannula (without limitation). This transition from the middle portion 120 to the distal portion 130 can be positioned at the mitral valve MV as shown in FIG. 1.

[0040] The distal portion 130 defines a plurality of elongate openings 135 (e.g., fenestrations, windows, slits, slots, channel openings, etc.) that extend through a tubular wall of the distal portion 130 and into the arterial lumen 1 12. The openings 135 allow arterial blood supplied from the arterial lumen 112 to enter the aorta AO of the patient. The openings 135 are the first and only openings of the arterial lumen 112 through which the oxygen-rich blood can be supplied to the patient via the cannula 100 (i.e.. the arterial lumen 112 is a fully continuously sealed lumen as it passes along within the proximal portion 110 and the middle portion 120).

[0041] Referring also to FIG. 5, a portion of the proximal portion 110 is shown to illustrate further the configurations of the venous lumen 111, the arterial lumen 112, and the inner wall 114. The proximal portion 110 illustrated here can also be representative of the middle portion 120 in some embodiments.

[0042] The heavy arrows in FIG. 5 represent blood flow through the dual lumens 111 , 112 of the proximal portion 110. Arrow 101 represents venous blood flow (i.e., oxygen-depleted venous blood mixed with oxygenated LA blood) through the venous lumen 111, and arrow 102 represents arterial blood flow ( / . e. , oxygenated blood) through the arterial lumen 112.

[0043] Here in FIG. 5 it can be seen that the venous lumen 11 1 and the arterial lumen 112 spiral or twist around each other along the length of the proximal portion 1 10 (and the middle portion 120 in some embodiments). That is the case because the inner wall 114 is configured in a twisted shape, similar to a double helix. It can be said that the blood flow through the proximal portion 110 follows a three-dimensional serpentine or serpiginous course or pathway. This configuration is advantageous because it facilitates both drainage from the entirety of the venous system without risking suction and allows minimization the size of the cannula 100 required for drainage. Increase in the velocity of blood results in concentric flow dynamics. Here, the spiral or twisted blood flow pathways will cause the plasma of the blood to tend to reside on the outer wall of the lumens while the cellular phase of blood red blood cells, platelets, etc.) will be more toward the middle of the cannula 100. The plasma thereby acts like a cushion for the red blood cells to help prevent red blood cell damage and / or thrombosis.

[0044] FIG. 6 illustrates another example technique for using the cannula 100. In this example, the cannula 100 is installed in an internal jugular vein JV and advanced to the heart H via the superior vena cava SVC. In such a case, the length of the cannula 100 can be shorter than the cannula 100 used for femoral vein access as shown in FIG. 1. Accordingly, it should be understood that the cannula 100 is scalable (in terms of both length and diameters) for various types of usages, patient sizes (including adult and pediatric), and other factors.

[0045] Additional Features and Embodiments

[0046] In some embodiments, the area defined by each of individual openings 115 of the proximal portion 110 is larger than the area defined by each of the individual openings 125 defined by the middle portion 120.

[0047] In some embodiments, the area defined by each of the individual openings 135 of the distal portion 130 is smaller than the area defined by each of the individual openings 125 defined by the middle portion 120.

[0048] In some embodiments, the elongate openings 115 of the proximal portion 110 and / or the elongate openings 125 of the middle portion 120 spiral around the central axis of the tubular proximal portion 110 or middle portion 120. In other words, the elongate openings 115 / 125 can follow a same direction or path that corresponds to the venous lumen 111.

[0049] Radiopaque markers can be positioned at any of multiple suitable positions on the cannula 100. For example, in some embodiments a series of radiopaque markers are positioned on the transition portion 116 and / or the distal portion 130.

[0050] While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described herein as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can, in some cases, be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

[0051] Particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. For example, the actions recited in the claims can be performed in a different order and still achieve desirable results. As one example, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous.

Claims

WHAT IS CLAIMED IS:

1. A cannula comprising: a proximal portion defining an arterial lumen and a venous lumen that is fluidly distinct from the arterial lumen; a distal portion defining the arterial lumen; and a middle portion extending between the proximal and distal portions, the middle portion defining the arterial and venous lumens, wherein the venous lumen terminates at a distal end of the middle portion.

2. The cannula of claim 1, wherein the proximal portion further defines a plurality of first elongate openings through a wall portion of the proximal portion that defines the venous lumen.

3. The cannula of claim 2, wherein the middle portion further defines a plurality of second elongate openings through a wall portion of the middle portion that defines the venous lumen.

4. The cannula of claim 3, wherein the distal portion further defines a plurality of third elongate openings through a wall portion of the distal portion that defines the arterial lumen.

5. The cannula of claim 3 or 4, wherein an open area of each first elongate opening of the plurality of first elongate openings is larger than an open area of each second elongate opening of the plurality of second elongate openings.

6. The cannula of any one of claims 2 through 5, wherein the first elongate openings extend along spiral paths around a central longitudinal axis of the proximal portion.

7. The cannula of any one of claims 1 through 6, wherein an outer diameter of the middle portion is smaller than an outer diameter of the proximal portion.

8. The cannula of claim 7, wherein an outer diameter of the distal portion is smallerthan the outer diameter of the middle portion.

9. The cannula of any one of claims 1 through 8, wherein a cross-sectional area of the venous lumen of the proximal portion is larger than a cross-sectional area of the arterial lumen of the proximal portion.

10. The cannula of claim 9, wherein the proximal portion comprises a tubular outer wall and an inner wall that separates the arterial lumen from the venous lumen.

11. The cannula of claim 10, wherein a cross-sectional shape of the tubular outer wall is a circle and a cross-section of the inner wall extends along a chord of the circle.

12. The cannula of claim 11, wherein the chord does not intersect a center of the circle.

13. The cannula of any one of claims 1 through 12, wherein the arterial and venous lumens of the proximal portion spiral around each other along a longitudinal length of the proximal portion.

14. A method of treating a patient, the method comprising: inserting a cannula into a femoral vein of the patient and advancing the cannula to a heart of the patient, the cannula comprising:(i) a proximal portion defining an arterial lumen and a venous lumen that is fluidly distinct from the arterial lumen;(li) a distal portion defining the arterial lumen; and(iii) a middle portion extending between the proximal and distal portions, the middle portion defining the arterial and venous lumens, wherein the venous lumen terminates at a distal end of the middle portion, wherein the proximal portion resides in an inferior vena cava and right atrium of the patient, wherein the middle portion crosses an atrial septum and resides in a left atrium of the patient, and wherein the distal portion extends from a left ventricle and into a aorta of the patient.

15. The method of claim 14, further comprising drawing venous blood of the patient into the venous lumen of the cannula from: (i) the inferior vena cava, (ii) the right atrium, and (iii) the left atrium.

16. The method of claim 15, further comprising supplying arterial blood to the aorta of the patient via the arterial lumen and the distal portion of the cannula.

17. The method of claim 1 , wherein the venous blood and blood from a left atrium, simultaneously draw n from the patient, is oxygenated outside a body of the patient and then returned to the aorta of the patient via the arterial lumen of the cannula.

18. A method of treating a patient, the method comprising: inserting a cannula into a jugular vein of the patient and advancing the cannula to a heart of the patient, the cannula comprising:(i) a proximal portion defining an arterial lumen and a venous lumen that is fluidly distinct from the arterial lumen;(ii) a distal portion defining the arterial lumen; and(iii) a middle portion extending between the proximal and distal portions, the middle portion defining the arterial and venous lumens, wherein the venous lumen terminates at a distal end of the middle portion, wherein the proximal portion resides in a superior vena cava and right atrium of the patient, wherein the middle portion crosses an atrial septum and resides in a left atrium of the patient, and wherein the distal portion extends from a left ventricle and into an aorta of the patient.

19. The method of claim 18, further comprising drawing venous blood of the patient into the venous lumen of the cannula from: (i) the superior vena cava, (ii) the right atrium, and (iii) the left atrium.

20. The method of claim 19, further comprising supplying arterial blood to the aorta of the patient via the arterial lumen and the distal portion of the cannula, wherein the venous blood drawn from the patient is oxygenated outside of the body of the patient and then returned to the aorta of the patient via the arterial lumen of the cannula.

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