Apparatus for dilating biological tissue

Abstract

An apparatus for dilating tissue of a patient includes an elongate introducer assembly (100) adapted to be positioned adjacent a puncture hole in a tissue wall. In use, the distal tip (122) and distal end (120) are advanced through the puncture hole (920) and the distal expansion portion is selectively positioned relative to the puncture hole. The outer slide shaft (110) can be advanced relative to the inner shaft (112) to cause radial expansion of the distal expansion portion and an increase in the outer diameter of the elongate introducer assembly at the distal expansion portion. Expansion of the puncture hole occurs as a result of the distal expansion portion in an expanded configuration passing through or spanning the puncture hole.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to devices and methods for selective dilation of a puncture hole in a tissue wall. More particularly, the device is configured to selectively dilate a puncture site formed in the fossa ovalis of the heart. [Background technology]

[0002] Transseptal puncture is a procedure commonly performed when a physician needs to access a left-sided chamber of the heart, such as the left atrium or left ventricle. The venous vasculature is accessed percutaneously and a catheter is used to facilitate delivery of a puncture device from a percutaneous access site to the fossa ovalis in the right atrium. The fossa ovalis is a thin tissue valve that covers the foramen ovale, a vestige of the fetal heart, and is the optimal site for puncture with a puncture device. Once an initial puncture hole is formed in the tissue, it must be dilated so that a treatment sheath can be delivered through the site. As treatments continue to evolve in their complexity and functionality, progressively larger treatment sheaths are required to pass through the puncture hole formed in the fossa ovalis. Known methods of dilating the puncture hole include the use of a dilator with a tapered distal end, which gradually dilates the puncture hole as the dilator advances across the fossa ovalis. Known dilators have a larger outer diameter so that the puncture hole is further dilated to accommodate a treatment sheath having a larger outer diameter. However, a dilator with a larger outer diameter may be more difficult to advance through the puncture because the distal end tapers only gradually over its length, and may potentially damage anatomical structures if it is too long. Creating a shorter tapered end that must taper rapidly to the larger outer diameter may be difficult, requiring a large force input to pass the dilator through the puncture. Additionally, a larger fixed outer diameter will also dilate the percutaneous access site, which may be undesirable.

[0003] Known sheaths can expand their resting inner lumen size in response to a larger device being inserted through the inner lumen. In a resting configuration, the sheath folds over itself and unfolds to expand the inner lumen when a larger object is passed through it. Unfortunately, inserting a larger object through the lumen of a known expandable sheath also expands the percutaneous access site, which may be undesirable. Furthermore, this requires the introduction of another device through the lumen of the expandable sheath into the patient's vasculature, increasing the risk of air embolism and / or thromboembolism.

[0004] Known basket catheters are often used with electroanatomical mapping systems. They have a distal end with splines that can be selectively deployed to expand the outer diameter of the distal end, the splines serving to facilitate efficient mapping of the heart via electrodes positioned along the splines. The distal extension can also be selectively contracted to accommodate smaller anatomical structures as well as removal of the device from the percutaneous access site. These basket catheters are complex to manufacture and typically feature splines that are included in a separate outer tubular member in addition to a separate inner tubular member. Furthermore, the splines are flexible structures that are prone to bunching and are designed to be atraumatic to the anatomical structures when the user intentionally contacts the splines with the anatomical structures in the heart. With this in mind, the splines do not have sufficient strength to expand tissue puncture holes.

[0005] Known balloon catheters have an inflatable balloon at the distal end of the device and can be used for dilating a puncture, such as for a balloon septotomy. The uninflated balloon portion of the catheter is placed across the puncture site and then the balloon is inflated, dilating the puncture site to the size of the inflated balloon. However, these devices are complex to manufacture and difficult to selectively control the specific degree of balloon inflation, thereby making it difficult to selectively control the degree to which the puncture is dilated. Indiscriminate dilatation of the puncture site can be detrimental to the health of the patient, and therefore the puncture site should only be dilated to the extent required for the necessary treatment sheath that must be inserted thereafter. Furthermore, when using a balloon catheter, an additional device must be inserted into the patient, increasing the risk of air embolism and / or thromboembolism. Thus, there is a need for an apparatus and method for selectively dilating a puncture hole in a tissue wall while reducing device exchanges, procedural complexity, and time. Summary of the Invention

[0006] In one broad aspect of the present disclosure, the elongate introducer assembly 100 includes an outer slide shaft 110 and an inner shaft 112. The elongate introducer assembly 100 is configured to be inserted into a patient 900 and positioned adjacent a tissue wall 910. The distal tip 122 is inserted through a puncture hole 920 in the tissue wall 910. The distal end portion 120 expands the puncture hole 920 until the distal end portion 120 protrudes from the puncture hole 920. The outer slide shaft 110 is selectively advanced over the inner shaft 112, which can take a number of forms as shown by different elements 140, 140a, 140b, to radially expand a distal extension portion continuous with the outer slide shaft 110, thereby increasing the outer diameter of the elongate introducer assembly 100 at the distal extension portion 140, 140a, 140b. The distal extension portions 140, 140a, 140b are in the expanded configuration when the distal extension portions 140, 140a, 140b span the puncture hole 920, thereby selectively expanding the puncture hole 920. Alternatively, the elongate introducer assembly 100 can be retracted and / or advanced through the puncture hole 920 to allow passage of the distal extension portions 140, 140a, 140b through the puncture hole 920 in the expanded configuration, thereby selectively expanding the puncture hole 920. Following expansion of the puncture hole 920, the outer slide shaft 110 can be selectively retracted on the inner shaft 112 to return the distal extension portions 140, 140a, 140b to the reduced expanded configuration.

[0007] In some examples, the elongate introducer assembly 100 further comprises a hollow lumen 118 extending along all or a portion of the length of the elongate introducer assembly 100 that can slidably receive the puncture device 200. The hollow lumen 118 may be centered or offset relative to the cross-sectional profile of the elongate introducer assembly 100. Once the distal tip 122 is proximate the tissue wall 910, the puncture device 200 can be pushed forward and advanced beyond the distal tip 122 to form a puncture hole 920 in the tissue wall 910. The puncture device 200 may be a sharp-tipped needle, a guidewire, a radiofrequency electrode, or any combination thereof.

[0008] In some embodiments, the distal extension portion 140, 140a of the elongate introducer assembly 100 comprises one or more distal buckling members 114 that are less stiff than the outer sliding shaft 110. As the outer sliding shaft 110 is advanced over the inner shaft 112, the distal buckling members 114 buckle to an extent that depends on the relative amount of selective advancement of the outer shaft 110 relative to the inner shaft 112. This buckling causes the elongate introducer assembly 100 at the distal extension portion 140, 140a to radially expand, resulting in an increase in the outer diameter of the elongate introducer assembly 100 at the distal extension portion 140, 140a. Retracting the outer slide shaft 110 relative to the inner shaft 112 from any selectively advanced state of the outer slide shaft 110 relative to the inner shaft 112 conversely reduces the degree of buckling in the distal buckling member 114 and causes a reduction in the outer diameter of the elongated introducer assembly 100 at the distal extension portions 140, 140a.

[0009] In another embodiment, the distal expansion portion 140 comprises one or more expansion members 116 adjacent to the one or more distal buckling members 114. The expansion members 116 may be stiffer than the distal buckling members 114 and positioned such that the expansion members 116 span the puncture hole 920. The expansion members 116 may be a distal portion of the outer slide shaft 110. When the outer slide shaft 110 is advanced relative to the inner shaft 112, the expansion members 116 radially expand, causing expansion of the puncture hole 920 that the expansion members 116 span. Alternatively, the elongate introducer assembly 100 may be retracted and / or advanced through the puncture hole 920 to allow passage of the distal expansion portion 140 through the puncture hole 920 in an expanded configuration, thereby selectively expanding the puncture hole 920.

[0010] In another embodiment, the distal extension portion 140b comprises a predetermined angled profile 128 on the inner shaft 112 and a distal portion of the outer slide shaft 110. Advancement of the outer slide shaft 110 causes the distal portion to traverse along the predetermined angled profile 128, resulting in radial expansion of the distal extension portion 140b of the elongate introducer assembly 100. The distal portion of the outer slide shaft 110 that traverses along the predetermined angled profile 128 of the inner shaft 112 may be configured into multiple split distal outer shaft segments 130 along the length of the outer slide shaft 110. The split distal outer shaft segments 130 allow for easy advancement over the predetermined angled profile 128 and radial expansion of the distal extension portion 140b.

[0011] In some examples, the outer sliding shaft 110 may be advanced by an outer sliding shaft advancer 126. The outer sliding shaft advancer 126 may be advanced and / or retracted along the elongated introducer assembly 100 via a button that is selectively depressed and released, allowing advancement and / or retraction of the outer sliding shaft 110 relative to the inner shaft 112 when depressed and locking the position of the outer sliding shaft 110 when released. Further methods of advancing the outer sliding shaft advancer 126 include rotationally driven advancement, whereby rotation of the outer sliding shaft advancer 126 causes advancement and / or retraction of the outer sliding shaft 110 through a threaded path around the elongated introducer assembly 100. Yet another aspect of advancing the outer sliding shaft advancer 126 may include frictional forces that must be overcome when advancing and / or retracting the outer sliding shaft 110 relative to the inner shaft 112.

[0012] In some embodiments, a number of indicators corresponding to the outer diameter of the distal extension portions 140, 140a, 140b are disposed along the length of the elongate introducer assembly 100. As the outer sliding shaft 110 is advanced relative to the inner shaft 112, the indicators correspond to the outer diameter of the distal extension portions 140, 140a, 140b associated with the amount the outer sliding shaft 110 has been advanced relative to the inner shaft 112.

[0013] In some embodiments, the elongate introducer assembly 100 includes a proximal hub 124 that can be grasped or handled when using the device. The proximal hub 124 may include features such as a female luer connector that allows for attachment of known accessories such as a syringe and / or a hemostasis valve.

[0014] In another broad aspect of the present disclosure, a method is provided for selective expansion of a puncture hole 920 in a tissue wall 910. The distal tip 122 of the elongate introducer assembly 100 is positioned proximate the puncture hole 920 in the tissue wall 910. The distal tip 122 of the elongate introducer assembly 100 is then advanced through the puncture hole 920, followed by advancement of the distal end 120. The distal extension portion 140, 140a is positioned until the distal extension portion 140 spans the puncture hole 920, and then the outer shaft 110 is advanced over the inner shaft 112 on the elongate introducer assembly 100, causing radial expansion of the distal extension portion 140, 140a.

[0015] In another aspect, the method includes positioning the distal tip 122 of the elongate introducer assembly 100 adjacent to a tissue wall 910. The puncture device 200 is advanced through the hollow lumen 118 on the elongate introducer assembly 100 and protrudes from the distal tip 122 to create a puncture hole 920 in the tissue wall 910. Following creation of the puncture hole 920 with the puncture device 200, the puncture hole 920 can be dilated using methods previously described.

[0016] In another embodiment, the method includes radially expanding the distal expansion portion 140, 140a before the distal expansion portion 140, 140a spans the puncture hole 920. The elongate introducer assembly 100 can then be advanced through the puncture hole 920 to cause further expansion of the puncture hole 920. The method may alternatively include expanding the distal expansion portion 140, 140a, 140b after the distal expansion portion 140, 140a, 140b has completely traversed the puncture hole 920. The elongate introducer assembly 100 can then be retracted through the puncture hole 920 to cause further expansion of the puncture hole 920.

[0017] In some embodiments, the elongate introducer assembly 100 has a proximal hub 124 with a female Luer connector for connection of a syringe and / or a hemostasis valve to facilitate injection and / or aspiration of fluids during any step of the method. [Brief description of the drawings]

[0018] In order that the invention may be more readily understood, embodiments thereof are illustrated by way of example in the accompanying drawings, in which: [Figure 1A] FIG. 1A is a partial cross-sectional view of an elongated introducer assembly. [Figure 1B] FIG. 1B is a partial cross-sectional view of an elongate introducer assembly with an expanded distal extension portion. [Figure 2A] FIG. 2A is a partial cross-sectional view of an elongated introducer assembly. [Figure 2B] FIG. 2B is a partial cross-sectional view of an elongate introducer assembly with an expanded distal extension portion. [Figure 3A] FIG. 3A is a partial cross-sectional view of an elongated introducer assembly. [Figure 3B] FIG. 3B is a cross-sectional view of an elongate introducer assembly having an expanded distal extension portion. [Figure 3C] FIG. 3C is a cross-sectional view of an elongate introducer assembly and a cross-sectional view of a distal extension portion. [Figure 3D] FIG. 3D is a cross-sectional view of an elongate introducer assembly and a cross-sectional view of an expanded distal extension portion. [Figure 4A] FIG. 4A is a partial cross-sectional view of an elongate introducer assembly positioned adjacent a puncture hole in a tissue wall. [Figure 4B] FIG. 4B is a partial cross-sectional view of an elongate introducer assembly with a distal tip protruding through a puncture in a tissue wall. [Figure 4C] FIG. 4C is a partial cross-sectional view of an elongate introducer assembly with an expansion member spanning a puncture in a tissue wall. [Figure 4D] FIG. 4D is a partial cross-sectional view of an elongate introducer assembly with an expanded distal extension portion spanning a puncture in a tissue wall. [Figure 4E] FIG. 4E is a partial cross-sectional view of the elongate introducer assembly with the expanded distal extension portion removed from the expanded puncture hole in the tissue wall. [Figure 5A]FIG. 5A is a partial cross-sectional view of an elongate introducer assembly with a distal extension portion spanning a puncture hole in a tissue wall. [Figure 5B] FIG. 5B is a partial cross-sectional view of an elongate introducer assembly with an expanded distal extension portion spanning a puncture in a tissue wall. [Figure 6A] FIG. 6A is a partial cross-sectional view of an elongated introducer assembly with a distal extension portion protruding through a puncture in a tissue wall. [Figure 6B] FIG. 6B is a partial cross-sectional view of an elongate introducer assembly with an expanded distal extension portion protruding through a puncture in a tissue wall. [Figure 6C] FIG. 6C is a partial cross-sectional view of the elongate introducer assembly with the expanded distal extension portion removed from the expanded puncture hole in the tissue wall. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] With particular reference now to the drawings in detail, it is emphasized that the details shown are by way of example and are for the purpose of describing particular embodiments of the invention only. Before describing at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. It is also to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting.

[0020] As described further below, the present invention provides an apparatus and method for dilating a puncture hole in a tissue wall, wherein an elongate introducer assembly with a distal dilation portion is used to span and dilate the puncture hole by advancing an outer sliding shaft relative to an inner shaft on the elongate introducer assembly.

[0021] Referring to FIG. 1A, elongated introducer assembly 100 is configured with a distal extension portion 140. It should be understood that FIG. 1A, like other partial cross sections described further herein, is shown in partial cross section, with the portion to the right of the wavy cut line being in cross section, but the portion to the left of the wavy cut line not being in cross section. Similarly, the wavy cut line is provided to illustrate that the length of assembly 100 is variable. The outer diameter of elongated introducer assembly 100 may be similar to other common percutaneous access devices used in the heart, and may have an outer diameter of about 7-8.5 Fr (3 Fr=1.0 mm), although any size that allows the device to be inserted percutaneously and through the intended vasculature into the heart is suitable. The overall length of elongated introducer assembly 100 may be any length that facilitates traversal of the device through the intended vasculature to reach the target tissue of the heart, and a length of about 60-110 cm may be suitable. The distal extension portion 140 is composed of a first distal buckling member 114a, an extension member 116, and a second distal buckling member 114b. The elements that make up the distal extension portion 140 are continuous with the outer slide shaft 110. The outer slide shaft 110 is an elongated member that surrounds all or part of the inner shaft 112. The first distal buckling member 114a and the second distal buckling member 114b have a lower mechanical stiffness than the outer slide shaft 110 and the extension member 116. The lower stiffness of the first distal buckling member 114a and the second distal buckling member 114b can be achieved by using a material with a lower stiffness compared to the outer slide shaft 110 and the extension member 116, removing material that forms the buckling members, flattening the material that forms the buckling members, using a smaller cross-sectional area of ​​the buckling members, or any combination thereof. Any suitable biocompatible material, such as stainless steel, nitinol, high density polyethylene (HDPE), low density polyethylene (LDPE), or any combination thereof, may be used to construct the first distal buckling member 114a, the second distal buckling member 114b, the outer slide shaft 110, and the inner shaft 112.In one suitable embodiment, the outer sliding shaft 110 is fabricated from a high density polymer, while the buckling members 114a, 114b are fabricated from a superelastic metal, such as Nitinol. The second distal buckling member 114b is fixedly secured to the inner shaft 112 at its distal end. The method of attaching the second distal buckling member 114b can be facilitated by adhesives, welding, reflow, the use of fasteners, or any suitable combination thereof. The expansion member 116 may be at least 1 mm long to allow the expansion member 116 to fully span the thickness of the tissue wall 910, although any length that accommodates the desired expansion is suitable. The expansion member 116 may be made from any suitable material and is stiffer than the first distal buckling portion 114a or the second distal buckling portion 114b.

[0022] Still referring to FIG. 1A , the distal end 120 terminating in a distal tip 122 constitutes the distal side of the elongate introducer assembly 100. The distal tip 122 may have an outer diameter between .035″ (0.889 mm) and .060″ (1.524 mm), although any diameter capable of being inserted through the required anatomy is suitable. From the distal tip, the distal end 120 may gradually taper in outer diameter to match the outer diameter of the remainder of the section comprising the outer slide shaft 110 and the distal extension portion 140. The elongate introducer assembly 100 may have a hollow lumen 118 extending along all or a portion of the length of the elongate introducer assembly 100. The hollow lumen may be used for infusion and / or aspiration of fluids, as well as insertion of accessory devices such as guidewires and / or needles. The hollow lumen 118 may be .032" (0.8128 mm) to .060" (1.524 mm) in diameter and may be centered or offset relative to the cross-sectional profile of the elongated introducer assembly 100, although any diameter that facilitates insertion of a desired accessory device is suitable. A proximal hub 124 is located proximally on the elongated introducer assembly 100 and may provide a user with a place to grasp during use. The proximal hub 124 may incorporate a female luer connector (known and not shown) to facilitate connection of a luer compatible device such as a syringe and / or a hemostasis valve (known and not shown). Along the length of the elongated introducer assembly 100 is an outer sliding shaft advancer 126, which is used to advance the outer sliding shaft 110 relative to the inner shaft 112. The outer sliding shaft advancer 126 may be actuated in any suitable manner. For example, the sliding shaft advancer 126 can be advanced and / or retracted along the elongate introducer assembly 100 via a button (not shown) that is selectively depressed and released, which when depressed allows advancement and / or retraction of the outer sliding shaft 110 relative to the inner shaft 112 and when released locks the position of the outer sliding shaft 110.Further methods of advancing the outer sliding shaft advancer 126 can include rotationally driven advancement (not shown), whereby rotation of the outer sliding shaft advancer 126 causes advancement and / or retraction of the outer sliding shaft 110 through a threaded path around the elongated introducer assembly 100. Yet another aspect of advancing the outer sliding shaft advancer 126 may include frictional forces (not shown) that must be overcome when advancing and / or retracting the outer sliding shaft 110 relative to the inner shaft 112.

[0023] 1B, the same embodiment as in FIG. 1A is shown, but now with the distal extension portion 140 in an actuated position displaced radially outward. The outer slide shaft 110 is advanced over the inner shaft 112 via the outer slide shaft advancer 126. Advancement of the outer slide shaft 110 causes the first distal buckling member 114a and the second distal buckling member 114b to buckle, lifting (i.e., radially displacing) the extension member 116 from the surface of the inner shaft 112. Lifting of the extension member 116 from the surface of the inner shaft 112 causes radial expansion of the elongated introducer assembly 100 at the distal extension portion 140. A number of indicators correlating to such radially expanded outer diameters of the distal extension portion 140 may be positioned along the length of the elongated introducer assembly 100. As the outer sliding shaft 110 is advanced relative to the inner shaft 112, the indicator corresponds to the outer diameter of the distal extension portion 140 associated with the amount the outer sliding shaft 110 has been advanced relative to the inner shaft 112. The distal extension portion 140 may have an outer diameter of 8.5-20 Fr (3 Fr=1.0 mm) when expanded, although any desired outer diameter that provides adequate expansion for the intended application is suitable.

[0024] 2A, an alternative embodiment of an elongate introducer assembly 100 is shown. The distal extension portion 140a includes a distal buckling member 114 and a distal portion of the outer sliding shaft 110. The distal buckling member 114 is fixedly secured to the inner shaft 112 at a distal end of the distal buckling member 114. Securing the distal buckling member 114 can be facilitated by the use of adhesives, welding, reflow, fasteners, or any combination thereof.

[0025] Referring to Figure 2B, the same embodiment as Figure 2A is shown, but now with the distal extension portion 140a displaced radially outward in an actuated position. The outer slide shaft 110 is advanced over the inner shaft 112 via the outer slide shaft advancer 126. Advancement of the outer slide shaft 110 causes buckling of the distal buckling member 114 and the distal portion of the outer slide shaft 110. This buckling causes the distal extension portion 140a to radially expand, increasing the outer diameter of the elongate introducer assembly 100 at the distal extension portion 140a.

[0026] 3A, there is shown an alternative embodiment of the elongate introducer assembly 100. The distal extension portion 140b includes a distal portion of the outer slide shaft 110 and a predetermined angled feature 128 on the inner shaft 112.

[0027] Referring to FIG. 3B, the same embodiment as FIG. 3A is shown, but now with the distal extension portion 140b in an actuated position displaced radially outward. The outer slide shaft 110 is advanced through the outer slide shaft advancer 126. The distal portion of the outer slide shaft 110 traverses along the predetermined inclined shape 128, thereby causing a radial expansion of the distal extension portion 140b of the elongate introducer assembly 100. The radial expansion of the distal extension portion 140b increases the outer diameter of the elongate introducer assembly 100 at the distal extension portion 140b. The portion of the outer slide shaft 110 that traverses along the predetermined inclined shape during advancement of the outer slide shaft 110 relative to the inner shaft 112 may be of the same material or a different material than the remainder of the outer slide shaft 110. Additionally, the distal portion of the outer slide shaft that is part of the distal extension portion 140b may have a different cross-sectional area than the remainder of the outer slide shaft 110.

[0028] Referring to Figure 3C, the same embodiment as Figure 3A is shown. A cross-sectional view of the distal extension portion 140b is shown. In this configuration, the outer slide shaft 110 is fully retracted relative to the inner shaft 112.

[0029] Referring to FIG. 3D, the same embodiment as FIG. 3A is shown, but now with the distal extension portion 140b in an actuated position displaced radially outward. A cross-sectional view of the distal extension portion 140b is shown. In this configuration, the outer slide shaft 110 has been advanced relative to the inner shaft 112. The cross-sectional view shows multiple split distal outer shaft segments 130a, 130b, 130c, 130d along the length of the outer slide shaft 110. The split distal outer shaft segments 130a, 130b, 130c, 130d are sections of the outer slide shaft 110 separated along the length of the outer slide shaft 110, allowing for easy advancement and radial expansion of the distal extension portion 140b over the predetermined ramp shape 128. The segmented distal outer shaft segments 130a, 130b, 130c, 130d are continuous with the outer slide shaft 110 and may be of the same or a different material as the remainder of the outer slide shaft 110. The segmented distal outer shaft segments 130a, 130b, 130c, 130d may have a different cross-sectional area than the remainder of the outer slide shaft 110. Any number of segmented distal outer shaft segments 130 may be used and they may be segmented to any length along the outer slide shaft 110.

[0030] Referring to Figure 4A, the same embodiment as Figure IA is shown. The distal tip 122 of the elongate introducer assembly 100 is positioned adjacent to a puncture hole 920 in a tissue wall 910 of a patient 900. The puncture device 200 is pushed forward through the hollow lumen 118 and past the distal tip 122 and used to create the puncture hole 920.

[0031] Referring to Figure 4B, the same embodiment as Figure IA is shown, continuing the procedure from Figure 4A, where the distal tip 122 is advanced through a puncture hole 920 in the tissue wall 910, the distal end 120 begins to traverse through the puncture hole 920, and gradually enlarges the diameter of the puncture hole 920 as the distal end 120 is advanced further through the puncture hole 920, causing the taper of the distal end 120 to expand proximally.

[0032] 4C, the same embodiment as in FIG IA is shown continuing the procedure from FIG 4B, with the distal end 120 advanced completely through the puncture hole 920 in the tissue wall 910 and the expansion member 116 spanning the puncture hole 920.

[0033] 4D, the same embodiment as in FIG. 1A is shown, continuing the procedure from FIG. 4C. The outer slide shaft 110 is advanced over the inner shaft 112 via the outer slide shaft advancer 126, causing the first and second distal buckling members 114a, 114b to buckle. The buckling of the first and second distal buckling members 114a, 114b causes the expansion member 116 to rise from the surface of the inner shaft 112, thereby causing a radial expansion of the elongate introducer assembly 100 at the distal expansion portion 140. The radial expansion at the distal expansion portion 140 causes the expansion of the puncture hole 920, as the tissue, including the tissue wall 910, accommodates the increased outer diameter of the elongate introducer assembly 100 at the distal expansion portion 140.

[0034] Referring to Figure 4E, the same embodiment as Figure 1A is shown, continuing the procedure from Figure 4D. The elongate introducer assembly 100 has been retracted from the puncture hole 920, and the distal expansion portion 140 no longer spans the puncture hole 920. As a result of the radial expansion of the distal expansion portion 140 in the previous procedural step, the puncture hole 920 has been expanded to a greater extent than shown in the procedural step shown in Figure 4C.

[0035] 5A, the same embodiment as in FIG 2A is shown, with the distal tip 122 and distal end 120 advanced through the puncture hole 920 and the distal extension portion 140a spanning the puncture hole 920.

[0036] 5B, the same embodiment as in FIG. 2A is shown, continuing the procedure from FIG. 5A, but now in an actuated position where the distal extension portion 140a is displaced radially outward while in the patient's tissue (e.g., the fossa ovalis). The outer slide shaft 110 has been advanced over the inner shaft 112 via the outer slide shaft advancer 126, causing the distal buckling member 114 and the distal portion of the outer slide shaft 110 to buckle, thereby causing radial expansion of the distal extension portion 140a and an increase in the outer diameter of the elongate introducer assembly 100 at the distal extension portion 140a. The radial expansion at the distal extension portion 140a causes the expansion of the puncture hole 920, as the tissue, including the tissue wall 910, accommodates the increased outer diameter of the elongate introducer assembly 100 at the distal extension portion 140a.

[0037] Referring to Figure 6A, the same embodiment as Figure 3A is shown. The distal extension 140b is comprised of a predetermined angled feature 128 on the inner shaft 112 and a plurality of segmented distal outer shaft segments 130 that are continuous with the outer slide shaft 110. The distal tip 122, distal end 120, and distal extension 140b have been advanced through the puncture hole 920.

[0038] Referring to Figure 6B, the same embodiment as Figure 3A is shown continuing the procedure from Figure 6A while the distal extension portion 140b is in an actuated position displaced radially outwardly while adjacent to the patient's tissue (e.g., the fossa ovalis). The outer slide shaft 110 has been advanced over the inner shaft 112 via the outer slide shaft advancer 126, causing the multiple split distal outer shaft segments 130 to traverse over the predetermined ramp shape 128, resulting in radial expansion of the distal extension portion 140b and an increase in the outer diameter of the elongate introducer assembly 100 at the distal extension portion 140b.

[0039] Referring to Figure 6C, the same embodiment as Figure 3A is shown, continuing the procedure from Figure 6B, while in the actuated position. The elongate introducer assembly 100 is retracted from the puncture hole 920, with the distal dilation portion 140b in the expanded configuration passing through the puncture hole 920. As the distal dilation portion 140b passes through the puncture hole 920, the tissue, including the tissue wall 910, accommodates the outer diameter of the distal dilation portion 140b, causing the puncture hole 920 to expand.

[0040] The above-described embodiments of the invention are intended to be exemplary only, and the scope of the invention is therefore intended to be limited only by the appended claims. It is to be understood that certain features of the invention that are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.

[0041] Although the present invention has been described in relation to its specific embodiment, it is apparent that many alternatives, modifications, and variations will be apparent to those skilled in the art. Therefore, it is intended to embrace all such alternatives, modifications, and variations that fall within the broad scope of the appended claims. All publications, patents, and patent applications mentioned in this specification are incorporated herein by reference in their entirety to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application should not be construed as an admission that such reference is available as prior art to the present invention.

Claims

1. 1. A device for expanding patient tissue, comprising: an elongate introducer assembly configured to be manipulated toward and positioned adjacent a puncture hole in a tissue wall, the elongate introducer assembly including an inner shaft and an outer slide shaft, the outer slide shaft being concentrically disposed relative to the inner shaft and longitudinally movable; a distal extension portion continuous with the outer slide shaft; Equipped with A device wherein selective linear movement of the outer slide shaft relative to the inner shaft actuates radial expansion of the distal expansion portion.

2. The device of claim 1 , wherein the distal extension portion is comprised of one or more distal buckling members that are less stiff than the outer slide shaft.

3. The device of claim 1 , wherein the distal extension portion is comprised of an extension member and one or more distal buckling members.

4. The device of claim 3 , wherein the expansion member is a segment of the outer sliding shaft adjacent the one or more distal buckling members.

5. The device of claim 3 or 4, wherein the distal buckling member is less stiff than the outer sliding shaft and the expansion member.

6. The apparatus of any one of claims 2 to 5, wherein the distal buckling member is constructed from Nitinol.

7. The device of claim 2 or 6, wherein the distal buckling member is formed by laser cutting or any other material removal process.

8. The device of claim 2 or 7, wherein the distal buckling member is formed by flattening.

9. The device of claim 2 or 8, wherein the distal buckling member is constructed from a polymeric material.

10. The device of claim 1 , wherein the distal extension portion is comprised of a predetermined tapered shape on the inner shaft and one or more segmented distal outer shaft segments on the outer sliding shaft.

11. The apparatus of claim 1 , wherein the outer slide shaft is selectively moved relative to the inner shaft via an outer slide shaft advancer.

12. The device of claim 1 , wherein the elongate introducer assembly includes an indicator along the length of the elongate introducer assembly that corresponds to an outer diameter of the distal extension portion associated with a position of the outer slide shaft relative to the inner shaft.

13. The device of claim 1 , wherein the inner shaft comprises a hollow lumen.

14. The apparatus of claim 1 , wherein the elongate introducer assembly includes a proximal hub.

15. The device of claim 14 , wherein the proximal hub has a female luer connector.

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