Balloon occlusive aortic cannula

Abstract

A balloon occlusive aortic cannula having a hollow cannula and an inflation lumen having a distal end and an expandable element surrounding the hollow cannul and having an exterior surface. The expandable element is disposed on the distal end of the inflation lumen. The expandable element having a micro surface texture formed on the exterior surface. The micro surface texture having a plurality of surface features configured to engage an aortic wall and form a fluidic seal therebetween during a cardiopulmonary bypass procedure.

Description

BALLOON OCCLUSIVE AORTIC CANNULACROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 552,349, filed on February 12, 2024. The entire disclosure of the above application is incorporated herein by reference.FIELD

[0002] The present disclosure relates to blood cannulas and, more particularly, relates to a blood cannula for use in cardiopulmonary bypass (CPB).BACKGROUND AND SUMMARY

[0003] This section provides background information related to the present disclosure which is not necessarily prior art. This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0004] Cardiopulmonary bypass (CPB) is a procedure performed to remove blood from the heart to allow for a bloodless view during heart surgery. CPB is utilized in the treatment of several diseases including coronary artery bypass grafting, aneurysm surgery, heart transplants, lung transplants, and heart valve surgery. CPB provides a bloodless state in the heart by circulating blood out of veins around the heart, passing it through a machine to be oxygenated and warmed, and then re-infused into arteries past the heart.

[0005] Patients undergoing CPB are put into a hypothermic state to lessen the metabolic demand on the heart and lungs during the procedure. However, induction of hypothermia and rewarming of the patient are time consuming procedures that contribute to massive inflammatory responses in patients - called systemic inflammatory response syndrome (SIRS). SIRS may contribute to several postoperative complications including myocardial dysfunction, respiratory failure, renal and neurologic dysfunction, bleeding disorders, impaired liver function, and in the worst cases multiple organ failure.

[0006] The present teachings provide a system and method to prevent or at least minimize cooling or circulatory arrest during CPB procedures to further minimize postoperative inflammation and complications. In some embodiments, the present teachings provide an aortic cannula that contains an expandable element to occlude the aorta and prevent back bleeding. In some embodiments, the present teachings further provide a solution that prevents the need for inducing hypothermia in patients undergoing CPB.

[0007] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.DRAWINGS

[0008] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0009] FIG. 1 is a schematic view of an aortic balloon cannula according to the principles of the present teachings with the balloon in an inflated state.

[0010] FIG. 2 is a schematic view of an aortic balloon cannula according to the principles of the present teachings with the balloon in a deflated state.

[0011] FIG. 3 is a schematic view of multiple aortic balloon cannulas according to the principles of the present teachings.

[0012] FIG. 4 illustrates a micro surface texture according to the principles of the present teachings.

[0013] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.DETAILED DESCRIPTION

[0014] Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art thatspecific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0015] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0016] When an element or layer is referred to as being "on," “engaged to,” "connected to," or "coupled to" another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," “directly engaged to,” "directly connected to," or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0017] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer orsection discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0018] Spatially relative terms, such as “inner,” “outer,” "beneath," "below," "lower," "above," "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0019] By way of background, it should be understood that cardiopulmonary bypass (CPB) is a procedure that enables cardiac surgeons to repair damage and / or fix a defect of the heart. Although the specific damage or defect can vary, CPB is typically used for preparing the heart for surgery. In essence, CPB provides a bloodless state in the heart by circulating blood out of veins around the heart, passing the blood through a machine to be oxygenated and warmed, and then re-infused into arteries past the heart, thereby bypassing blood flow through the heart.

[0020] More particularly, the process generally comprises i) emptying the heart by draining blood via venous cannulas, ii) oxygenating the blood with an oxygenator (also leads to a bypassing of the lungs), iii) adjusting the chemical and electrolyte contents of the blood, iv) adjusting the temperature of the blood using a heat exchanger (this is needed mainly because patients are frequently put under mild to severe hypothermia to lessen the metabolic demand on the heart and lungs during the procedure), and v) returning blood to the patient via an aortic cannula.

[0021] Generally, there are three types of aortic cannula typically used for CPB, including a distal descending aortic cannula (near the heart), a femoral aortic cannula, or an axillary aortic cannula (near the heart). There are several advantages and disadvantages of conventional aortic cannulas. For example, right angled cannulas typically prevent perforating the posterior wall of the aorta; however, they can selectively perfuse an arch branch. Additionally, straight cannulas typically prevent selective arch vessel perfusion; however, they can penetrate the posterior wall of theaorta. Beveled tip cannulas typically provide: easier insertion; however, they can produce a higher pressure gradient delivered at the tip. Diffusion tip cannulas typically provide less pressure gradient which enables better perfusion of arch branches; however, they are slightly more difficult to use. Wire reinforced cannulas enable higher flow for a smaller size cannula and are more immune to iatrogenic dissection; however, they lack additional operational refinements. Finally, flanges cannulas are hemostatic and act as anchor points for the purse string sutures, with several disadvantages.

[0022] On the other hand, aortic cannulas provide features of the aforementioned cannula in a single device, including an angled tip cannula with wire reinforcement and flange.

[0023] As mentioned above, the induction of hypothermia is common practice in patients undergoing the CPB procedure. This helps lessen the demand put on the heart and lungs and ensure complete circulatory arrest so the heart is bloodless for performing the next procedure. However, induction of hypothermia and rewarming of the patient are time consuming procedures that contribute to massive inflammatory responses in patients - called systemic inflammatory response syndrome.

[0024] SIRS contributes to several post-operative complications including myocardial dysfunction, respiratory failure, renal and neurologic dysfunction, bleeding disorders, impaired liver function, and in the worst cases multiple organ failure.

[0025] The present teachings provide a system and a method that prevent or at least minimize the need for cooling or circulatory arrest during CPB procedures, thereby minimizing post-operative inflammation and complications.

[0026] According to the present teachings, an aortic balloon cannula 10 is provided and configured for use in CPB procedures having advantageous construction and methods of use. In some embodiments, aortic balloon cannula 10 comprises an expandable element 12 surrounding the cannula 10, such as a compliant balloon 12, disposed on a distal end 14 of an inflation lumen 16. Expandable element 12 is configured to be inflated or otherwise enlarged to produce and / or form a seal or sealing engagement against the aortic wall to prevent back bleeding. In some embodiments, aortic balloon cannula 10 comprises a stylet configured to permit aortic balloon cannula 10 to be placed over a guidewire via the Seidinger technique. Aortic balloon cannula 10 is of sufficient internal diameter so that it can provide 3-4 liters of antegrade flow against the arterial pressure of 60-80 mmHg.

[0027] In some embodiments, expandable element 12 further comprises a micro surface texture 20, best shown in FIG. 4, formed upon an exterior surface 22 thereof to further enhance coupling and / or anchoring of expandable element 12 relative to the aortic wall. In some embodiments, the micro surface texture 20 is provided on a rubber or rubber-like material by Hoowaki®. In some embodiments, micro surface texture 20 comprises a plurality of surface features. In some embodiments, the surface features comprise clusters of raised texture features formed in the shape of rings 24. In some embodiments, the rings 24 having a 2 mm outer diameter and 1 mm inner diameter. Each of the rings 24 or other configuration can comprise a plurality of individual pillars / protrusions 26 extending upwardly from exterior surface 22 being generally elongated and / or tapered. In some embodiments, each of the individual pillars 26 is 100 microns tall, 25 microns wide at the tip, and has a draft angle of 10 degrees that results in a base being about 80 microns wide. In some embodiments, pillars 26 or other micro surface textures 20 are disposed at a pitch of about 200 microns resulting in tips being about 175 microns apart and pillar bases about 120 microns apart. According to some embodiments, the pillars / protrusions 26 can be up to 150 microns tall, 50 microns wide at the tip and 150 microns wide at the base.

[0028] It should be understood that micro surface texture 20 can define any of a number of configurations, including but not limited to protuberances, indentations, radial strips, axial strips, circular rings, oblong rings, angular portions, uniform, non-uniform, and other distributions.

[0029] It has been found that micro surface texture 20 provides improved holding force when expandable element 12 is inflated or enlarged. In some embodiments, it has been shown that expandable element 12, when inflated with 25 cc of fluid (e.g., water) using micro surface texture 20 in the form of strips and in the form of a circumferential pattern was capable of providing 11.3N and 31.3N of retention force (pulling), respectively. For comparison, a Terumo® control balloon provided only 3.3N and a CODA control balloon (over inflation to 35 cc) provided only 5.5N. As shown in FIG. 3, multiple cannulas 10 of varying sizes can be utilized in multiple arteries.

[0030] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. Thesame may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

CLAIMSWhat is claimed is:1 . A balloon occlusive aortic cannula comprising: a hollow cannula; an inflation lumen having a distal end; an expandable element having an exterior surface, the expandable element being disposed around the hollow cannula and on the distal end of the inflation lumen, the expandable element having a micro surface texture formed on the exterior surface, the micro surface texture having a plurality of surface features configured to engage an aortic wall and form a fluidic seal therebetween during a cardiopulmonary bypass procedure.

2. The balloon occlusive aortic cannula according to Claim 1 wherein the expandable element is a compliant expandable element.

3. The balloon occlusive aortic cannula according to Claim 1 wherein the plurality of surface features of the micro surface texture comprises a plurality of protuberances.

4. The balloon occlusive aortic cannula according to Claim 1 wherein the plurality of surface features of the micro surface texture comprises a plurality of raised texture features.

5. The balloon occlusive aortic cannula according to Claim 4 wherein the plurality of raised texture features is disposed in a ring shape.

6. The balloon occlusive aortic cannula according to Claim 5 wherein the ring shape comprises about a 2mm outer diameter and about a 1 mm inner diameter.

7. The balloon occlusive aortic cannula according to Claim 4 wherein the plurality of raised texture features comprises a plurality of raised pillars.

8. The balloon occlusive aortic cannula according to Claim 1 wherein the micro surface texture is configured to engage the aortic wall and form a fluidic seal sufficient to provide more than 6 N of removal force.

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