TECHNICAL FIELD

The presently disclosed subject matter relates generally to transseptal access devices and more particularly to a transseptal access stability system (TASS) for reducing complications that may arise when performing transseptal punctures.

BACKGROUND

The left atrium of the heart is a challenging cardiac chamber to access

percutaneously. Puncturing the interatrial septum, a procedure known as a transseptal puncture, permits a direct route from the right atrium to the left atrium. Transseptal puncture procedures often involve the use of a venous sheath housing a needle capable of puncturing the interatrial septum through the fossa ovale and are critical for many invasive procedures performed in a cardiac catheterization laboratory.

Transseptal puncture procedures, however, come with a significant risk of complications, many of which can be serious and life-threatening. While the incidence of complications has been reduced through advancements in sheath and real-time imaging technology, certain anatomic variations can increase the risk of serious complications. In particular, patients with atrial septal aneurysms remain at a particularly high risk of cardiac perforation that may require emergent cardiac surgery or even result in death. Current tools aimed to improve the safety profile of transseptal puncture procedures have limited efficacy.

SUMMARY

In some aspects, the presently disclosed subject matter provides a transseptal access stability system (TASS) comprising a cardiac catheter, wherein the cardiac catheter comprises: a venous sheath comprising an orifice defined by a rim at a distal end thereof, wherein the rim is configured to secure a fossa ovale thereto, and wherein the venous sheath is fluidly coupled to at least one of a vacuum source and a cryoenergy source at a proximal end thereof; and a hollow dilator having a transseptal needle operationally positioned therein, wherein the dilator and needle are axially positioned through the venous sheath and wherein the dilator and the needle each have a distal end configured to protrude from the orifice at the distal end of the venous sheath and are adapted to be advanced and retracted to puncture a interatrial septum through the fossa ovale.

In some aspects of the presently disclosed TASS, the venous sheath is curved at the distal end by an angle a, which in particular aspects can have a range from about 0 degrees to about 160 degrees. In some aspects, angle a is fixed, whereas in other aspects, angle a is adjustable, for example, by a steering mechanism.

In some aspects, the venous sheath comprises a plurality of channels, wherein the plurality of channels is fluidly coupled to at least one of a vacuum source and a cryoenergy source at a proximal end thereof.

In yet other aspects, the presently disclosed subject matter provides a method for performing a transseptal puncture on a subject in need of treatment thereof, the method comprising: (a) providing a transseptal access stability system (TASS) as disclosed herein and a J- wire; (b) accessing the femoral venous of the subject and inserting a J- wire into the vein thereof; (c) advancing the venous sheath with the assembled dilator of the TASS over the J-wire and into the vein; (d) once positioned in the heart of the subject, removing the J-wire and leaving the venous sheath and the dilator in place; (e) inserting the needle into the dilator; (f) positioning the venous sheath/dilator/needle assembly against the septum of the fossa ovale; (g) advancing the venous sheath over the dilator/needle until the venous sheath is in direct contact with the septal tissue; (h) applying suction force to the venous sheath; (i) performing the transseptal puncture by puncturing the interatrial septum with the needle; and (j) releasing the suction force and advancing the venous sheath and the dilator across the punctured septum.

In yet further aspects the presently disclosed subject matter provides a kit comprising: (a) a transseptal access stability system of claim 1; and (b) a J-wire. In particular aspects, the kit comprises instructions for use of the kit for performing a transseptal puncture on a subject in need of treatment thereof.

Certain aspects of the presently disclosed subject matter having been stated hereinabove, which are addressed in whole or in part by the presently disclosed subject matter, other aspects will become evident as the description proceeds when taken in connection with the accompanying Examples and Drawings as best described herein below.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described the presently disclosed subject matter in general terms, reference will now be made to the accompanying Drawings, which are not necessarily drawn to scale, and wherein:

FIG. 1 illustrates a schematic diagram of an embodiment of the presently disclosed transseptal access system (TASS);

FIG. 2 illustrates a side view of another embodiment of the presently disclosed

TASS, illustrating a plurality of channels comprising the venous sheath, which are in fluid communication with a plurality of pores configured to secure the fossa ovale thereto;

FIG. 3 illustrates a plan view of the porous end cap of the TASS shown in FIG. 2; FIG. 4A and FIG. 4B illustrate perspective views of another embodiment of the presently disclosed TASS comprising the cardiac catheter with a plurality of channels therein, wherein each channel has its own independently controlled vacuum or cryoenergy source;

FIG. 4C is a plan view and a side view of an embodiment of the TASS shown in FIGS. 4A and 4B including an end cap that is configured to allow a continuous flow of cryogen in and out of the cap;

FIG. 5 illustrates a flow diagram of an example of a method of performing a transseptal puncture using the presently disclosed TASS;

FIG. 6 shows another configuration of the TASS shown in FIG. 1 in a

disassembled state; and

FIG. 7 shows a configuration of the TASS shown in FIG. 6 in an assembled state.

DETAILED DESCRIPTION

The presently disclosed subject matter now will be described more fully hereinafter with reference to the accompanying Drawings, in which some, but not all embodiments of the presently disclosed subject matter are shown. Like numbers refer to like elements throughout. The presently disclosed subject matter may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Indeed, many modifications and other embodiments of the presently disclosed subject matter set forth herein will come to mind to one skilled in the art to which the presently disclosed subject matter pertains having the benefit of the teachings presented in the foregoing descriptions and the associated Drawings.

Therefore, it is to be understood that the presently disclosed subject matter is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims.

As used herein, the term "fossa ovale" refers to a depression in the right atrium of the heart and is the remnant of a thin fibrous sheet that covers the foramen ovale during fetal development. An aneurysm can occur if the foramen ovale does not close properly. When an aneurysm occurs in the fossa ovale, an enlarged pouch is formed. This pouch can protrude into the right atrium or the left atrium. An aneurysm can occur even if the foramen ovale seals properly.

In some embodiments, the presently disclosed transseptal access stability system (TASS) includes a venous sheath that is designed to improve the safety profile of transseptal access in patients who have anatomical variants that may not be amenable to traditional approaches. More particularly, the venous sheath is designed for reducing the likelihood of atrial septal aneurysms when performing transseptal punctures. One of ordinary skill in the art would recognize, however, that the presently disclosed TASS can be used in any transseptal procedure and is not limited for use in patients with an atrial septal aneurysm. Further, any transseptal sheath currently known in the art can be retrofitted with the presently disclosed TASS. In some embodiments, the presently disclosed TASS is disposable and intended for a single use.

More particularly, in one embodiment, the TASS uses suction force for securing the fossa ovale against the rim of the orifice of the venous sheath. In another

embodiment, the TASS uses cryo-based energy for securing the fossa ovale against the rim of the orifice of the venous sheath. Once the venous sheath is secured against the fossa ovale, the venous sheath can be retracted along with the fossa ovale to move it away from the left atrial free wall region. Puncturing of the fossa ovale can then be performed safely with minimal concern for perforating through to the free wall of the left atrium.

Referring now to FIG. 1 is a schematic diagram of an embodiment of a TASS 100 for reducing the likelihood of atrial septal aneurysms when performing transseptal punctures. The presently disclosed TASS 100 includes a cardiac catheter 110 that is supplied by either a vacuum source 150 or a cryoenergy source 160. The cardiac catheter 110 includes a hollow venous sheath 115, which is, for example, a 9.5Fr sheath, although other diameter sheaths could be suitable for use with the presently disclosed TASS. Venous sheath 115, in some embodiments, as illustrated in FIG. 2 herein below, can include a plurality of channels originating at the proximal end thereof, which are fluidly coupled to and can be supplied by either a vacuum source 150 or a cryoenergy source 160.

Referring once again to FIG. 1, in some embodiments, a steering mechanism 120 and a hemostatic valve 125 are coupled to the proximal end of the cardiac catheter 110. Catheter steering mechanisms known in the art can be adapted to be suitable for use with the presently disclosed TASS. A dilator 130 and a needle 135 are fed through the hollow venous sheath 115, the steering mechanism 120, and the hemostatic valve 125 as shown in FIG. 1 such that they are positioned axially within the hollow venous sheath 115 (see insert A-A). Needles known in the art can be adapted to be suitable for use with the presently disclosed TASS. Needle 135 optionally is provided with the presently disclosed TASS or, in other embodiments, needle 135 can be supplied separately. The distal end of the venous sheath 115 has an orifice 140 through which the distal ends of the dilator 130 and the needle 135 can protrude. Orifice 140 is defined by rim 140a. In some embodiments, as illustrated in FIG. 2 herein below, rim 140a can comprise a porous end cap coupled thereto, which includes a plurality of pores in fluid

communication with the plurality of channels.

The venous sheath 115, the dilator 130, and the needle 135 can be advanced, retracted, and, in some embodiments, steered independently and in a controlled fashion. Detail A in FIG. 1 shows an expanded view of the orifice 140 and rim 140a of the venous sheath 115, including an expanded view of the dilator 130 and needle 135. Detail A also shows that the distal end of the venous sheath 115 can be set at an angle a with respect to a longitudinal axis AX along the length of the venous sheath 115. The angle a can range from about 0 degrees to about 160 degrees, including 0, 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, and 160 degrees, ± 5 degrees and any whole or fractional integer in between. Further, in some embodiments, the angle a is adjustable through a mechanism within the venous sheath 115 so that the operator can custom tailor the degree of angulation. The steering mechanism 120 (e.g., a dial) is used to change the steerability and angulation of the venous sheath 115.

In one embodiment, the vacuum source 150 is fluidly coupled to the venous sheath 115 via a side port 145. A regulator 155 may be associated with the vacuum source 150 for controlling uniform vacuum pressure within the venous sheath 115. More particularly, in this embodiment, a vacuum (i.e., a pressure significantly below atmospheric pressure) exists in the space between the venous sheath 115 and the dilator 130. When in use, suction force is used to secure the fossa ovale against the rim 140a of the orifice 140 of the venous sheath 115.

In another embodiment, the cryoenergy source 160 is fluidly coupled to the venous sheath 115 via the side port 145. A regulator 165 may be associated with the cryoenergy source 160 for controlling the flow of coolant and thereby controlling the temperature at the orifice 140 of the venous sheath 115. More particularly, in this embodiment, the rim 140a of the orifice 140 of the venous sheath 115 is cooled to cryogenic temperatures. When in use, cryoenergy is used to secure the fossa ovale against the rim 140a of the orifice 140 of the venous sheath 115, i.e., the fossa ovale adheres to the rim 140a of the orifice 140.

Referring now to FIG. 2 is a side view of a TASS 200, which is another embodiment of the presently disclosed TASS. More particularly, FIG. 2 further defines the presently disclosed venous sheath, which stabilizes the fossa ovale, secures the interatrial septum, and allows for a safe needle puncture. In such embodiments, the presently disclosed TASS 200 includes a cardiac catheter 210. The cardiac catheter 210 includes a venous sheath 215. Venous sheath 215 includes a plurality of channels 220 originating at the proximal end thereof, which can be supplied by either a vacuum source or a cryoenergy source (not shown), such as the vacuum source 150 or the cryoenergy source 160 shown in FIG. 1. Cardiac catheter 210 further includes catheter insertion cavity (or lumen) 230 for receiving a dilator 232 and a needle 235. FIG. 2 also shows a cross-sectional view of the cardiac catheter 210 taken along line A- A of the side view, which shows more details of the channels 220 and the catheter insertion cavity 230 of the cardiac catheter 210.

Referring once again to FIG. 2, the venous sheath 215 of cardiac catheter 210 includes a porous end cap 240a, which is coupled to orifice 240 at the distal end thereof. Porous end cap 240a includes a plurality of pores 250. More details of the porous end cap 240a are shown with reference to FIG. 3.

Referring now to FIG. 3 is a plan view of the porous end cap 240a of the TASS 200 shown in FIG. 2. Also shown in FIG. 3 are cross-sectional views of examples of pores 250, taken along line B-B of the plan view. Namely, the plurality of pores 250 can have any shape and geometry configured to improve the suction force for securing the fossa ovale thereto. Representative geometries of the plurality of pores 250 include, but are not limited to, a straight-walled hole 250a, an idealized taper 250b, a trumpet geometry 250c, a wine glass geometry 250d, and a champagne flute geometry 250e.

Referring now to FIG. 4A is a perspective view of an TASS 400, which is yet another embodiment of the presently disclosed TASS. In this embodiment, the cardiac catheter of the TASS 400 comprises a plurality of independently controlled channels. For example, the TASS 400 comprises a cardiac catheter 410. The cardiac catheter 410 includes a venous sheath 415. The venous sheath 415 of the cardiac catheter 410 further includes a catheter insertion cavity (or lumen) 420 for receiving a dilator (not shown) and a needle (not shown). Integrated into the walls of the venous sheath 415 is a plurality of channels 425 originating at the proximal end thereof.

In one example, the venous sheath 415 comprises eight channels 425. In this example, each of the eight channels 425 has a flexible fluid line 430 extending from the proximal end of the venous sheath 415. Further, each of the flexible fluid lines 430 has a coupler 435. Each of the eight channels 425 is supplied by its own vacuum source 150 or cryoenergy source 160. For example, using the eight couplers 435, the eight channels 425 are supplied by eight vacuum sources 150, respectively, or by eight cryoenergy sources 160, respectively. Accordingly, each of the eight channels 425 can be independently controlled. Venous sheath 415 can comprise a plurality of channels 425, including 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or more channels 425.

Referring now to FIG. 4B is an expanded view of the distal end of the venous sheath 415 of the cardiac catheter 410. In particular, FIG. 4B shows that the distal end of the venous sheath 415 can be set at a substantially fixed angle a with respect to a longitudinal axis AX along the length of the venous sheath 415. The angle a can range from about 0 degrees to about 160 degrees. Further, the angle a is adjustable through a mechanism within the venous sheath 415 so that the operator can custom tailor the degree of angulation.

Referring now to FIG. 4C, a plan view and a side view of cap 440 is provided. Cap 440 can fit over the distal end of venous sheath 415 and has channels 445 that substantially align with channels 425 of venous sheath 415. Cap 440 also has a channel 450 that is common to all of channels 445 which allows a continuous flow of cryogen in and out of cap 440. A gas, e.g., nitrous oxide, can flow through cap 440, and when it expands upon exiting one or more of channels 425, causes cap 440 to cool and adhere to the fossa ovale when contacted with the tissue thereof. The cryogen can be continuously supplied to cap 440 by cryoenergy source 160 one or more channels 425 and removed from cap 440 by vacuum applied to one or more channels 425 by vacuum source 150. In some embodiments, channel 420 also is available for supplying and/or removing the cryogen from cap 440. In embodiments comprising cap 440, TASS 400 is substantially a close-looped system.

Referring to FIG. 1 through FIG. 4B, while the presently disclosed TASS 100, 200, or 400 are shown to comprise steerable sheaths, the TASS 100, 200, or 400 can comprise non-steerable sheaths that have different degrees of angles preformed.

Referring now to FIG. 5 is a flow diagram of an example of a method 500 of performing a transseptal puncture using the presently disclosed TASS 100, 200, or 400. The method 500 may include, but is not limited to, the following steps.

At a step 510, the presently disclosed TASS 100, 200, or 400 is provided.

However, by way of example, the steps to follow will reference the components of TASS 100. For example and referring now to FIG. 6, a certain configuration of TASS 100 is provided. FIG. 6 shows an example of TASS 100 that is provided in a disassembled state. Namely, FIG. 6 shows separately the cardiac catheter 110, the dilator 130 (e.g., a plastic dilator), and a J-wire 170 (e.g., a 0.035 inch J-wire). J-wire 170 can be provided with TASS 100 or, in some embodiments, J-wire 170 is provided separately. The cardiac catheter 110 has the vacuum source 150 (e.g., a syringe) coupled thereto via the side port 145. In this configuration, TASS 100 also includes a pressure gauge 152 and a one-way valve (not shown).

At a step 515, in preparation for use, the venous sheath 115 is flushed and the cardiac catheter 110, the dilator 130, and the J-wire 170 are assembled together, as shown, for example, in FIG. 7. Namely, FIG. 7 shows the dilator 130 inserted into a catheter insertion cavity (or lumen) 117 of the venous sheath 115 and the J-wire 170 inserted in a lumen 132 of the dilator 130.

At a step 520, using TASS 100, the femoral venous is accessed in the standard clinical manner and the J-wire 170 is inserted into the vein.

At a step 525, the venous sheath 115 with the assembled dilator 130 is advanced over the J-wire 170 and into the vein.

At a step 530, once positioned in the heart, the J-wire 170 is removed leaving the venous sheath 115 and the dilator 130 in place.

At a step 535, a needle (e.g., the needle 135) is inserted into the dilator 130. At a step 540, the venous sheath 115/dilator 130/needle 135 assembly is positioned against the septum of the fossa ovale.

At a step 545, the venous sheath 115 is advanced over the dilator 130/needle 135 assembly until the venous sheath 115 is in direct contact with the septal tissue.

At a step 550, using the vacuum source 150 (e.g., a syringe), suction force is applied to the venous sheath 115.

At a step 555, the transseptal puncture is performed using the needle 135.

At a step 560, the suction force is released and the venous sheath 115 and the dilator 130 are advanced across the punctured septum. In some embodiments, the presently disclosed subject matter provides a kit comprising: (a) a transseptal access stability system of disclosed herein; and a J-wire. In further embodiments, the kit includes instructions for use of the kit for performing a transseptal puncture on a subject in need of treatment thereof, for example, steps of method 500 disclosed immediately hereinabove.

In summary, the presently disclosed TASS is designed to significantly improve the safety profile of transseptal access in patients that have anatomical variants that may not be amenable to traditional approaches. Namely, the venous sheath is designed for reducing the likelihood of atrial septal aneurysms when performing transseptal punctures. In one embodiment, the TASS uses suction force from the vacuum source for securing the fossa ovale. In another embodiment, the TASS uses cryo-based energy for securing the fossa ovale. Once the venous sheath is secured against the fossa ovale, the venous sheath can be retracted along with the fossa ovale to move it away from the left atrial free wall region. Puncturing of the fossa ovale can then be performed safely with minimal concern for perforating through to the free wall of the left atrium. The subject treated by the presently disclosed methods in their many

embodiments is desirably a human subject, although it is to be understood that the methods described herein are effective with respect to all vertebrate species, which are intended to be included in the term "subject."

A "subject" can include a human subject for medical purposes, such as for the treatment of an existing condition or disease or the prophylactic treatment for preventing the onset of a condition or disease, or an animal subject for medical, veterinary purposes, or developmental purposes. Suitable animal subjects include mammals including, but not limited to, primates, e.g., humans, monkeys, apes, and the like; bovines, e.g., cattle, oxen, and the like; ovines, e.g., sheep and the like; caprines, e.g., goats and the like; porcines, e.g., pigs, hogs, and the like; equines, e.g., horses, donkeys, zebras, and the like; felines, including wild and domestic cats; canines, including dogs; lagomorphs, including rabbits, hares, and the like; and rodents, including mice, rats, and the like. An animal may be a transgenic animal. In some embodiments, the subject is a human including, but not limited to, fetal, neonatal, infant, juvenile, and adult subjects. Further, a "subject" can include a patient afflicted with or suspected of being afflicted with a condition or disease. Thus, the terms "subject" and "patient" are used interchangeably herein. Following long-standing patent law convention, the terms "a," "an," and "the" refer to "one or more" when used in this application, including the claims. Thus, for example, reference to "a subject" includes a plurality of subjects, unless the context clearly is to the contrary (e.g., a plurality of subjects), and so forth.

Throughout this specification and the claims, the terms "comprise," "comprises," and "comprising" are used in a non-exclusive sense, except where the context requires otherwise. Likewise, the term "include" and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items.

For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing amounts, sizes, dimensions, proportions, shapes, formulations, parameters, percentages, quantities, characteristics, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term "about" even though the term "about" may not expressly appear with the value, amount or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are not and need not be exact, but may be approximate and/or larger or smaller as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art depending on the desired properties sought to be obtained by the presently disclosed subject matter. For example, the term "about," when referring to a value can be meant to encompass variations of, in some embodiments, ± 100% in some embodiments ± 50%, in some embodiments ± 20%>, in some embodiments ± 10%, in some embodiments ± 5%, in some embodiments ±1%, in some embodiments ± 0.5%, and in some embodiments ± 0.1% from the specified amount, as such variations are appropriate to perform the disclosed methods or employ the disclosed compositions.

Further, the term "about" when used in connection with one or more numbers or numerical ranges, should be understood to refer to all such numbers, including all numbers in a range and modifies that range by extending the boundaries above and below the numerical values set forth. The recitation of numerical ranges by endpoints includes all numbers, e.g., whole integers, including fractions thereof, subsumed within that range (for example, the recitation of 1 to 5 includes 1, 2, 3, 4, and 5, as well as fractions thereof, e.g., 1.5, 2.25, 3.75, 4.1, and the like) and any range within that range.

Although the foregoing subject matter has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be understood by those skilled in the art that certain changes and modifications can be practiced within the scope of the appended claims.