The present invention relates, in general, to devices and methods for assisting a patient's heart with a cannula. More specifically, the present invention is related to devices and methods for assisting a patient's heart with a cannula where the cannula is of sufficient length to, for example, extend from the patient's internal jugular vein to the pulmonary artery.
Traditional cannulae used for patient life support generally involve single lumen cannulae at multiple insertion sites, high volume circuits, and cannulae that are not capable of long-term use. Multiple insertion sites increase the risk of bleeding, vessel damage, infection, as well as pain and discomfort to the patient. These cannulae are designed and built for short-term acute therapies. Additionally, traditional cannulae usually require access sites located in the patient's groin area near the right or left femoral veins.
Patients with severe right-sided circulatory and/or right-sided ventricular failure have significantly high mortality and morbidity caused by a multitude of factors in multiple patient populations. Historically, Right Ventricular Assist Devices (RVADs) and Left Ventricular Assist Devices (LVADs) have been adapted for use on surgical patients without a percutaneous or catheter lab option available. These surgical RVADs have been applied on patients with right inferior myocardial infarction, acute right-sided ischemic myocardial infarctions (with large left and right propagation), cardiogenic shock, LVAD-created right ventricular dysfunction, post-transplant right ventricular failure, and pulmonary hypertension. Acute myocardial infarction and cardiogenic shock have been treated with intra-aortic balloon pumps and maximal inotropic support, to which many patients become refractory. Surgically implanted LVADs can create a significant septal shift that leads to a dynamic change in the Starling curve that abruptly places patients into severe right ventricular failure. Patients can limit post-transplant survival bridged to transplant to/from an RVAD with severe right ventricular failure. Secondary pulmonary hypertension leads to an exacerbation of right ventricular failure in acute and chronic situations, which may be treated with RVADs.
The foregoing conventional devices do not have the capability to reach the pulmonary artery (PA) from the internal jugular vein via a percutaneous insertion. Some traditional cannulae are inserted into the patient's heart through a direct access point in the patient's right or left femoral vein. Alternatively, traditional RVADs have a cannula either primarily placed in the PA or a graft sewn onto the PA, then a cannula inserted through the graft. The assembly can then be visualized in the PA via fluoroscopy and X-Ray with the aid of distal markers in the cannula, verifying the proper orientation of the outflow to the patient. In these embodiments, the patient's torso length can limit the ability to access the PA via percutaneous insertion. If a cannula is not of a proper length, the interventional procedure may not unload the right ventricle, which leads to an increase of morbidity and mortality. Furthermore, traditional venoarterial extracorporeal membrane oxygenation (VA ECMO) is the current standard of care used to treat right ventricular failure and respiratory failure percutaneously. VA ECMO procedure draws blood from the right atrium and pumps it through an oxygenator and back into the arterial circulation via the femoral artery. VA ECMO bypasses the lungs and the heart completely. Therefore, residual blood is left stagnant in both the heart and lungs potentially leading to thrombosis and an inadequately unloaded right ventricle. Additionally, the arterial cannulation can lead to problems including but not limited to bleeding, stroke, and infection.
In view of the foregoing, there is a need for a dual lumen cannula with a single insertion point. There is an additional need for a dual lumen cannula that eliminates multiple access sites, reduces bleeding, vessel damage, and infection, as well as pain and discomfort to the patient. Furthermore, there exists a need for a dual lumen cannula that enables patients to be ambulatory with access sites provided in the neck area instead of the groin.
In one embodiment, a dual lumen coaxial cannula assembly includes a first infusion tube having a first elongate body defining a first lumen therethrough and a second drainage tube co-axially aligned with the infusion tube and having a second clongate body with a second lumen defined by a space between the first infusion tube and second drainage tube. The first infusion tube may have a proximal end, a distal end, and a sidewall extending circumferentially therebetween. A first connector portion may be provided at the proximal end of the first infusion tube for coupling the first insertion tube to a connector. The second drainage tube may have a proximal end, a distal end, and a sidewall extending circumferentially therebetween. A second connector portion may be provided at the proximal end of the second drainage tube for coupling the second drainage tube to the connector. In accordance with another embodiment, a connector may be removably attached to the first connector portion and the second connector portion for coupling the first infusion tube and the second drainage tube to an extracorporeal blood circuit.
According to another embodiment, the first infusion tube may include a plurality of infusion apertures provided at the distal end. The infusion apertures may extend through the sidewall of the first infusion tube. Similarly, the second drainage tube may include a plurality of drainage apertures provided at the distal end, the drainage apertures extending through the sidewall of the second drainage tube. The plurality of infusion apertures may extend through the sidewall of the first infusion tube in a direction perpendicular to a longitudinal axis of the first infusion tube. In a similar manner, the plurality of drainage apertures may extend through the sidewall of the second drainage tube in a direction perpendicular to a longitudinal axis of the second drainage tube. Alternatively, the plurality of infusion apertures may extend through the sidewall of the first infusion tube at an acute or obtuse angle with respect to a longitudinal axis of the first infusion tube. Similarly, the plurality of infusion apertures extends through the sidewall of the first infusion tube at an acute or obtuse angle with respect to a longitudinal axis of the first infusion tube.
In another embodiment, a wire mesh basket is provided inside the first lumen at a location surrounding the plurality of infusion apertures for supporting and preventing collapse of the sidewall of the first infusion tube. In a similar manner, a wire mesh basket is provided inside the second lumen at a location surrounding the plurality of drainage apertures for supporting and preventing collapse of the sidewall of the second drainage tube. A reinforcing coil may extend from the proximal end to the distal end of one or both of the first infusion tube and the second drainage tube. The reinforcing coil desirably extends in a helical manner along the length of one or both of the first infusion tube and the second drainage tube.
In accordance with another embodiment, the connector may further include a distal aperture in fluid communication with an inlet portion and an outlet portion, and a barbed fitting on the inlet portion and the outlet portion for connecting an infusion line and a drainage line to the connector. The dual lumen coaxial cannula may be adapted for inserting into an internal jugular vein of a patient. In another embodiment, the dual lumen coaxial cannula may be adapted for maneuvering through the patient's vasculature such that the first distal end of the first infusion cannula is at least within proximity of the patient's pulmonary artery and such that the second distal end of the second drainage cannula is at least within proximity of the patient's right atrium.
According to a further embodiment, a method of assisting a patient's heart may include the step of providing a dual lumen coaxial cannula assembly having a first infusion tube having a first elongate body defining a first lumen therethrough and a second drainage tube coaxially aligned with the infusion tube and having a second elongate body with a second lumen defined by a space between the first infusion tube and second drainage tube.
The first infusion tube may have a proximal end, a distal end, and a sidewall extending circumferentially therebetween. A first connector portion may be provided at the proximal end of the first infusion tube for coupling the first insertion tube to a connector. The second drainage tube may have a proximal end, a distal end, and a sidewall extending circumferentially therebetween. A second connector portion may be provided at the proximal end of the second drainage tube for coupling the second drainage tube to the connector. In accordance with another embodiment, a connector may be removably attached to the first connector portion and the second connector portion for coupling the first infusion tube and the second drainage tube to an extracorporeal blood circuit. The method may further include the step of inserting the dual lumen coaxial cannula into an internal jugular vein of the patient, wherein the dual lumen coaxial cannula has a length to extend from the patient's neck area to the patient's heart. The method may also include the step of maneuvering the dual lumen coaxial cannula through the patient's vasculature such that the first distal end of the first infusion cannula is at least within proximity of the patient's pulmonary artery and such that the second distal end of the second drainage cannula is at least within proximity of the patient's right atrium. In another embodiment, the method may also include the steps of connecting the connector to a blood pump for establishing right ventricular support and inserting a guidewire to guide the dual lumen coaxial cannula during the maneuvering step. Blood from the blood pump may be delivered to the patient's pulmonary artery through the plurality of infusion apertures of the first infusion tube. Desirably, blood may be withdrawn from the patient's right atrium through the plurality of drainage apertures of the second drainage cannula.
Further details and advantages of the present invention will be understood from the following detailed description read in conjunction with the accompanying drawings.
For purposes of the description hereinafter, spatial orientation terms, if used, shall relate to the referenced embodiment as it is oriented in the accompanying drawing figures or otherwise described in the following detailed description. However, it is to be understood that the embodiments described hereinafter may assume many alternative variations and embodiments. It is also to be understood that the specific devices illustrated in the accompanying drawing figures and described herein are simply exemplary and should not be considered as limiting.
Referring to the drawings, in which like reference characters refer to like parts throughout the several views thereof, various embodiments of a coaxial, dual lumen cannula 10 (hereinafter referred to as “coaxial cannula 10”) are shown. With initial reference to
The first infusion tube 12 is disposed within the second drainage tube 14 in a coaxial arrangement centered about a central axis 16. Each of the first infusion tube 12 and the second drainage tube 14 has a first circumference defining a first lumen and a second circumference defining a second lumen, respectively. The first circumference of the first infusion tube 12 is smaller than the second circumference of the second drainage tube 14 such that the first infusion tube 12 may be placed within the second lumen of the second drainage tube 14. One or both of the first infusion tube 12 and the second drainage tube 14 may be manufactured from a medical-grade material such as polyurethane. Alternatively, the tubes may be made from PVC or silicone, and may be dip molded, extruded, co-molded, or made using any other suitable manufacturing technique.
The coaxial cannula 10 has sufficient placement flexibility adapted for placement of the coaxial cannula 10 within a patient's body. Desirably, a vascular insertion site is provided at the internal jugular vein on the patient's neck area. The coaxial cannula 10 is adapted for placement above or below the right atrium of the patient's heart. The coaxial cannula 10 may be used with an introducer to guide the placement of the coaxial cannula 10 as it is inserted within the patient's body.
With continuing reference to
A plurality of infusion apertures 18 is provided at a distal end of the first infusion tube 12. The plurality of infusion apertures 18 is desirably arranged in a circular pattern extending around the outer circumference of the first infusion tube 12. In some embodiments, the plurality of infusion apertures 18 may be disposed in multiple groups provided at various sites on the first infusion tube 12. Similarly, the second drainage tube 14 includes a plurality of drainage apertures 20 provided at a distal end of the second drainage tube 14. The plurality of drainage apertures 20 is desirably arranged in a circular pattern extending around the outer circumference of the second drainage tube 14. In alternative embodiments, the plurality of drainage apertures 20 may be arranged in groups disposed at various sites along the length of the second drainage tube 14. The infusion apertures 18 are separated from the drainage apertures 20 by a distance D. In different embodiments of the coaxial cannula 10, the separation of infusion apertures 18 from drainage apertures 20 determines the amount of mixing of oxygenated blood and unoxygenated blood. This distance may vary based on the age and size of the patient, as well as the desired flow rates during the medical procedure where the coaxial cannula 10 is used. For example, a coaxial cannula 10 having a specific overall length and diameter, along with a desired pattern and distance between the infusion apertures 18 and the drainage apertures 20 may be selected based on age and/or size of the patient.
With continuing reference to
With reference to
With specific reference to
The total cross-sectional area of the plurality of infusion apertures 18 is desirably approximately equal to or greater than the cross-sectional area of the first lumen 29. If the cross-sectional area of the plurality of infusion apertures 18 is less than the cross-sectional area of the first lumen 29, an undesirable pressure drop may occur. This pressure drop reduces the flow throughput within the first lumen 29 and impairs the efficiency of the first infusion tube 12. Desirably, the total cross sectional area of the plurality of infusion apertures 18 exceeds the cross sectional area of the first lumen 29 such that if one or more of the infusion apertures 18 becomes clogged, the total cross sectional area of the remaining infusion apertures 18 is equal to or greater than the cross sectional area of the first lumen 29. In this manner, the blood flow through the first lumen 29 is maximized even if one or more of the infusion apertures 18 become clogged.
With reference to
With specific reference to
The total cross sectional area of the plurality of drainage apertures 20 is desirably approximately equal to or greater than the cross sectional area of the second lumen 46. If the cross sectional area of the plurality of drainage apertures 20 is less than the cross sectional area of the second lumen 46, an undesirable pressure drop within the second drainage tube 14 may occur. This pressure drop reduces the flow throughput within the second lumen 46 and impairs the efficiency of the second drainage tube 14. Desirably, the total cross sectional area of the plurality of drainage apertures 20 exceeds the cross sectional area of the second lumen 46 such that if one or more drainage apertures 20 becomes clogged, the total cross sectional area of the remaining drainage apertures 20 is equal to or greater than the cross sectional area of the second lumen 46. In this manner, the blood flow through the second lumen 46 is maximized even if one or more of the drainage apertures 20 becomes clogged.
With reference to
With reference to
The connector includes a distal aperture 52 at a distal end of the connector 22 for connecting to the proximal end of the coaxial cannula 10. The proximal end of the connector 22 has the inlet portion 24 and the outlet portion 26 in fluid communication with the distal aperture 52. The outlet portion 26 may include a barbed fitting 54 for connecting a drainage connection 57 that extends to a blood pump. The inlet portion 24 includes an inner tube 56 that extends through the interior of the connector 22 and connects with the first infusion tube 12. The inner tube 56 may extend beyond the distal aperture 52 for connecting with the first infusion tube 12. A drainage opening 58 connects the second drainage tube 14 with the outlet portion 26 of the connector 22. The drainage opening 58 is coextensive with the inner tube 56 along the length of the body portion of the connector 22. The inner tube 56 may be reinforced with a metal or plastic coil 60 that extends in a helical manner along the length of the inner tube 56 to minimize kinking and/or collapse of the first infusion tube 12.
With continuing reference to
In use, the proximal end of the coaxial cannula 10 is connected to the distal aperture 52 of the connector 22. The inner tube 56 receives blood from a supply line 62 and sends it through the lumen of the inner tube 56 to the first infusion tube 12. As the diameter of the inner tube 56 is smaller than the diameter of the drainage opening 58, the inner tube 56 extends through the interior of the connector 22, thus allowing the inner tube 56 to be continuous throughout the length of the connector 22. Depending on the application, the inner tube 56 may or may not include structural reinforcement in the form of the coil 60. In embodiments where the inner tube 56 is reinforced with the coil 60, the inner tube 56 is stronger and less susceptible to kinking or collapse.
The connector 22 may be made from polycarbonate as an example, but could also be made from PVC, acrylic, or polyurethane. The connector 22 may be constructed using one or more manufacturing techniques including injection molding, machining, or dip forming. One of ordinary skill in the art will understand that a variety of other manufacturing techniques may be used for constructing the connector 22 without departing from the intended scope of the invention.
With continued reference to
Having described several non-limiting embodiments of the coaxial cannula 10 and the connector 22, an exemplary and non-limiting method for supporting the right heart of a patient using the coaxial cannula 10 and the connector 22 will now be described with reference to
While several embodiments of a coaxial cannula are shown in the accompanying figures and described hereinabove in detail, other embodiments will be apparent to, and readily made by, those skilled in the art without departing from the scope and spirit of the invention.
The present application is a continuation application of U.S. application Ser. No. 17/518,224, filed Nov. 3, 2021, which is a continuation application of U.S. application Ser. No. 16/404,317, filed May 6, 2017, which is a continuation application of U.S. patent application Ser. No. 15/720,005, filed Sep. 29, 2017, now U.S. Pat. No. 10,279,101, which is a continuation application of U.S. patent application Ser. No. 14/869,506, filed Sep. 29, 2015, now U.S. Pat. No. 9,782,534, which is a continuation application of U.S. patent application Ser. No. 13/718,110, filed Dec. 18, 2012, now U.S. Pat. No. 9,168,352, which claims priority to U.S. Provisional Patent Application No. 61/577,257, filed Dec. 19, 2011, entitled “Dual Lumen Cannula”, the entire disclosures of which are incorporated by reference herein.
Number | Date | Country | |
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61577257 | Dec 2011 | US |
Number | Date | Country | |
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Parent | 17518224 | Nov 2021 | US |
Child | 18435343 | US | |
Parent | 16404317 | May 2019 | US |
Child | 17518224 | US | |
Parent | 15720005 | Sep 2017 | US |
Child | 16404317 | US | |
Parent | 14869506 | Sep 2015 | US |
Child | 15720005 | US | |
Parent | 13718110 | Dec 2012 | US |
Child | 14869506 | US |