Hybrid Transseptal Dilator

Abstract

A method and apparatus are provided for an optimized transseptal procedure for performing left heart entry that reduces the number of devices used to minimize surgical time, complexity, and cost. The hybrid dilator (100) provides the combined functionality of a transseptal sheath and a dilator assembly. The hybrid dilator includes a dilator shaft (100) defining a lumen (104) for receiving a crossing device and structured to support the crossing device when the crossing device is used to create a puncture in tissue, and a distal tip (130) having an outer diameter that tapers to an outer diameter of the crossing device to provide a smooth transition between the crossing device and the distal tip when the crossing device is inserted from the lumen and protrudes from the distal tip.

Description

[Technical field]

[0001] The present disclosure relates to medical devices for use in entering the cardiovascular system. More particularly, the present disclosure relates to a hybrid transseptal dilator for facilitating transseptal procedures for entering the left heart.

[0002] In order that the invention may be readily understood, embodiments thereof are shown by way of example in the accompanying drawings, in which: [Brief description of the drawings]

[0003] [Figure 1A] FIG. 1 is an illustration of a hybrid extender, in accordance with one embodiment of the present invention. [Figure 1B] FIG. 1B is an illustration of the proximal portion of the hybrid dilator of FIG. 1A. [Figure 1C] FIG. 1B is a front end view of the distal tip of the hybrid dilator of FIG. 1A. [Figure 1D] FIG. 1B is an illustration of the proximal portion of the hybrid dilator of FIG. 1A. [Figure 2A] 2A is a cross-sectional view of the distal tip of the hybrid dilator according to line 2A-2A of FIG. 1C. [Figure 2B] FIG. 2B is a cross-sectional view of the distal-most end of the hybrid dilator according to line 2B-2B of FIG. 1C. [Figure 2C] 13 is an illustration of a distal tip according to an alternative embodiment of the present invention. [Figure 3A] 13A-13C show alternative embodiments of a distal tip according to alternative embodiments of the present invention. [Figure 3B] 13A-13C show alternative embodiments of a distal tip according to alternative embodiments of the present invention. [Figure 3C] 13A-13C show alternative embodiments of a distal tip according to alternative embodiments of the present invention. [Figure 3D] 13A-13C show alternative embodiments of a distal tip according to alternative embodiments of the present invention. [Figure 4A]1A-1D show a hybrid dilator according to one embodiment of the present invention and a standard sheath / dilator assembly that can be used in a standard transseptal procedure. [Figure 4B] FIG. 13 shows the proximal portion of a hybrid dilator according to one embodiment of the present invention. [Figure 4C] FIG. 13 shows the proximal portion of a hybrid dilator according to one embodiment of the present invention. [Figure 4D] FIG. 13 shows the proximal portion of a hybrid dilator according to one embodiment of the present invention. [Figure 4E] FIG. 13 shows the proximal portion of a hybrid dilator according to one embodiment of the present invention. [Figure 4F] FIG. 13 shows the proximal portion of a hybrid dilator according to one embodiment of the present invention. [Figure 4G] FIG. 13 shows the proximal portion of a hybrid dilator according to one embodiment of the present invention. [Figure 5A] FIG. 13 illustrates a proximal portion of a hybrid dilator according to an alternative embodiment of the present invention. [Figure 5B] FIG. 13 illustrates a proximal portion of a hybrid dilator according to an alternative embodiment of the present invention. [Figure 5C] FIG. 13 illustrates a proximal portion of a hybrid dilator according to an alternative embodiment of the present invention. [Figure 5D] FIG. 1 illustrates a hybrid expander according to an alternative embodiment of the present invention. [Figure 5E] 13A-13C illustrate an alternative embodiment of a proximal hub in accordance with an embodiment of the present invention. [Figure 6A] FIG. 1 is an illustration of how to use the sheath and dilator according to a standard transseptal procedure. [Figure 6B] 1 is a flow chart showing the steps in a standard transseptal procedure. [Figure 7A] 1A-1C are illustrations of a method for performing a transseptal puncture procedure using a hybrid dilator, according to one embodiment of the present invention. [Figure 7B]1 is a flow chart illustrating the steps of a method for performing a transseptal puncture procedure using a hybrid dilator, in accordance with one embodiment of the present invention. [Figure 8] FIG. 13 is a cross-sectional view of the shaft and distal tip of a hybrid dilator of an alternative embodiment of the present invention. [Figure 9] FIG. 9 is an enlarged view of the distal tip of FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0004] When performing transseptal procedures to enter the left atrium of the heart, physicians typically use sheaths and dilators to support the crossing or puncture device. In some cases, physicians may be unable to cross the sheath into the left atrium because the transition between the sheath and the dilator may be clogged or blocked by tissue boundaries, resulting in the sheath being unable to cross (or difficult to cross) the penetration hole. In other words, tissue may get stuck at the sheath / dilator interface. Thus, using multiple devices in transseptal procedures may make it difficult for the surgeon to complete the procedure due to the transition of the instruments between the various devices that may get caught at the septal tissue interface. The problem of transseptal punctures performed using crossing devices supported by sheath and dilator sets making transitions that may be blocked on tissue when crossing the septum can be addressed by eliminating this transition by using hybrid dilators (described herein) instead of sheath and dilator sets, which have the appropriate functionality (flexibility, pushability, torqueability, distal taper, etc.) to facilitate smooth crossing.

[0005] In one broad aspect, embodiments of the invention include a hybrid dilator for use with a crossing device in a tissue puncture procedure, the hybrid dilator including a dilator shaft defining an inner lumen for receiving the crossing device and structured to support the crossing device when the crossing device is used to effect a puncture in tissue, and a distal tip having an outer diameter that tapers to an outer diameter of the crossing device to provide a smooth transition between the crossing device and the distal tip when the crossing device is inserted from the inner lumen and protrudes from the distal tip. In some such embodiments, the dilator shaft includes an inner layer, an outer layer, and a torque layer therebetween.

[0006] In another broad aspect, an embodiment of the invention includes a kit for puncturing tissue, the kit having a crossing device with puncturing features and a hybrid dilator having a dilator shaft defining a lumen for receiving the crossing device and structured to support the crossing device when the crossing device is used to effect puncture in tissue. The hybrid dilator also includes a distal tip having an outer diameter that substantially tapers to an outer diameter of the crossing device to cooperate to provide a smooth profile as the hybrid dilator is advanced through tissue over the crossing device. In some embodiments of the kit, the crossing device is a mechanical needle with a sharp tip, and in some other embodiments, the crossing device is configured to deliver energy to tissue.

[0007] In another broad aspect, an embodiment of the invention includes a system for puncturing tissue, the system including a crossing device having a puncturing feature operable to deliver energy to tissue, an electrosurgical generator operable to provide energy to the puncturing feature, and a hybrid dilator having a dilator shaft defining a lumen for receiving the crossing device and structured to support the crossing device when the crossing device is used to effect a puncture in tissue, the hybrid dilator also including a distal tip having an outer diameter that tapers substantially to an outer diameter of the crossing device to cooperate to provide a smooth profile as the hybrid dilator is advanced over the crossing device and through tissue.

[0008] In yet another broad aspect, embodiments of the invention include a method of using a hybrid dilator and a crossing device to puncture a cardiac septum, the method including the steps of (a) positioning a distal tip of the hybrid dilator at a desired location on the septum, (b) using the hybrid dilator to support a crossing device disposed within a lumen of the hybrid dilator as the crossing device is advanced beyond the distal tip of the hybrid dilator to puncture the septum, and (c) dilating the desired location by advancing the hybrid dilator over the crossing device.

[0009] In one broad aspect, a hybrid dilator is provided as a composite device that includes one or more essential features of a transseptal dilator or sheath, or a combination thereof, in a single device to provide the combined functionality of a transseptal sheath and dilator assembly in an optimal manner. Some of these features that provide the combined functionality of a sheath and dilator assembly may include shaft stiffness, curvature, and internal and external tapers that may be incorporated along the distal portion of the hybrid dilator, including the distal tip, to facilitate traversal of the hybrid dilator. Additionally, in some cases, the hybrid dilator may include features that facilitate manipulation of the hybrid dilator and / or provide directional information, such as tactile cues or indications to communicate the direction of the distal tip curvature to facilitate transseptal surgery. In some cases, these features may be incorporated in the proximal portion of the hybrid dilator, such as in a combined proximal hub.

[0010] In another broad aspect, an optimized method for performing a transseptal medical procedure is provided that results in streamlining surgical workflow by providing a hybrid dilator that incorporates the improved functionality of a conventional transseptal sheath and dilator assembly. The hybrid dilator of the present invention allows for a reduction in the number of devices required to complete a transseptal procedure, thereby increasing surgical efficiency and reducing surgical time and complexity.

[0011] In some circumstances, if the initial transseptal entry procedure is successfully completed with a standard sheath and dilator assembly, the sheath may not be large enough to support subsequent advancement of a relatively larger outer diameter (OD) catheter for procedures on the left heart. As a result, the sheath and dilator assembly may have to be removed, and the catheter may then be advanced into the left heart by advancing across the septum over the guidewire in place. In other cases, physicians may wish to use a larger delivery sheath for complex procedures (such as left atrial appendage closure / occlusion procedures), knowing that the product may not be able to cross, so they may introduce a standard transseptal kit (including a sheath, dilator, and guidewire) for crossing and pre-dilating the septum. The three-piece kit is then removable for replacement and then disposable, so that the three products (sheath, dilator, guidewire) are only used for a short period of the procedure. Thus, in some cases, the sheath and dilator assembly may only be useful for performing the initial transseptal puncture, which leads to waste as multiple devices are used. Additionally, the use of multiple devices to perform transseptal procedures increases the time and complexity of the procedure and contributes to additional costs. Furthermore, increased clinical intervention of the left heart has created an increased need for safe and reliable transseptal solutions.

[0012] In some embodiments, oversized hybrid dilators are provided that reduce the number of physical / geometric transitions and instrument transitions, both of which can cause difficulty or tactile disturbances when a physician completes a transseptal or other tissue crossing. Some examples include smooth lines and tapers to facilitate a smooth, seamless transition across the tissue.

[0013] Additionally, the inventors have discovered a method for performing transseptal medical procedures that streamlines surgical workflow by providing a hybrid dilator that replaces conventional transseptal sheath and dilator assemblies. The hybrid dilator of the present invention allows for a reduction in the number of devices required to complete a transseptal procedure. This reduces the number of elements a physician needs to prepare and assemble for a transseptal procedure and introduce into a patient. The method of the present invention provides a dilator that can be used with a guidewire for entry, replacing a sheath, dilator, and guidewire assembly.

[0014] With specific reference now made to the details of the drawings, it is emphasized that the details are given by way of example and are for the purpose of discussing the description of certain 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 the construction and 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. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0015] In some embodiments, a single / integral device in the form of a hybrid dilator is provided that provides a smooth taper feature to facilitate both device traversal and exchange in transseptal procedures, and also provides the physician with tactile feedback and distal curvature indication that is substantially equivalent to that provided by a sheath / dilator assembly.

[0016] According to one embodiment of the present invention, a hybrid dilator 100 is provided as shown in FIG. 1A. The hybrid dilator 100 includes a combination of features that provide dual functionality of a sheath and dilator to facilitate transseptal puncture procedures and avoid the shortcomings of conventional sheath and dilator assemblies. The hybrid dilator 100 provides the smoothness of a standard transseptal dilator with the control of a standard transseptal sheath. More specifically, the hybrid dilator 100 functions as a single device that eliminates the need to use a conventional sheath / dilator assembly and reduces waste by eliminating the need for assembly. The hybrid dilator 100 includes a sheath-like handle with familiar torque and tactile controls. In the specific example shown, the hybrid dilator 100 defines a proximal portion 110 that includes a molded-together proximal hub 112 as shown in FIG. 1B and FIG. 1D. A distal portion 120 is coupled to the proximal portion 110 that includes a dilator shaft. The dilator shaft further defines a curved distal end 130 extending from the proximal end and terminating in a distal tip 140, as shown in FIG. 1C.

[0017] Dilator shaft / support and column strength / positioning The dilator shaft is formed from a smooth distal tubing 121 that is coupled to a molded proximal hub 112. The distal tubing 121 narrows at the distal tip 140 and defines a lumen 122 therein that may be used to flush the device prior to use. In some embodiments, the hybrid dilator 100 is provided in a single, integral device, meaning that it is one product that is flushed, unlike prior art sheath / dilator assemblies that require each product to be flushed. The dilator shaft provides mechanical properties that make the surgical procedure the easiest. As further shown in FIG. 2A, at the distal tip 140, the distal tubing 121 transitions through a smooth external taper T3 that widens proximally to a larger outer diameter OD than conventional transseptal kit dilators to dilate the septum to a size appropriate for a subsequent delivery device or instrument that may be used. The OD of the distal tubing 121 is substantially constant from the proximal edge of the distal tip 140 to the proximal hub 112 to which the distal tubing is bonded or attached. In some such embodiments, the OD of the hybrid dilator 100 may vary based on the application and clinical use. In some embodiments, the size of the hybrid dilator 100 is from about 12 French to about 20 French. In a specific example, the hybrid dilator has a size of about 12.5 French (outer diameter of about 0.163 inches (0.414 cm) to about 0.166 inches (0.421 cm)). In another example, the hybrid dilator has a size of about 15 French (outer diameter of about 0.193 inches (0.490 cm) to about 0.205 inches (0.521 cm)).

[0018] Distal end curved state In some embodiments of the present invention, the distal end 130 of the hybrid dilator 100 may be curved as shown in FIG. 1A. Alternatively, the distal end 130 of the hybrid dilator may be straight. In some embodiments in which the distal end 130 of the hybrid dilator 100 is curved, the hybrid dilator 100, in combination with a puncture device such as a needle, forms a trajectory that is substantially equivalent to the trajectory achieved with the sheath / dilator / needle assembly combination of a conventional transseptal kit to provide the physician with a predictable and repeatable path to complete the transseptal puncture. The curved distal end 130 makes it easy to advance the hybrid dilator 100 in conjunction with the puncture device to initiate the transseptal puncture.

[0019] In some such embodiments, the hybrid dilator 100 includes a shaft formed from a distal tubing 121 having sufficient stiffness to allow a crossing device, such as a puncture needle or guidewire, to be positioned therethrough while maintaining the position of the assembly at a desired location, such as a septal fossa. As such, the hybrid dilator 100 functions to provide support and columnar strength to facilitate positioning of the crossing device at a desired location. As disclosed above and shown in FIG. 1A, the distal tubing 121 tapers proximally from the distal tip 140 to provide a larger OD defining an expanding interface to allow for expansion of the puncture site 510 (FIG. 6A) to facilitate the advancement of additional devices.

[0020] Distal Tip More specifically, as shown in FIG. 2A, the distal tip 140 provides a lumen 142 suitable for a crossing device, such as a puncture device, to be inserted, and defines a relatively thin wall to facilitate control of puncture. In some such examples, the puncture device is a mechanical needle or an RF puncture device that can be used with the hybrid dilator 100. The hybrid dilator 100 provides a limited distal inner diameter (as shown by ID2 and ID3) at the distal tip 140 to control the distance that a puncture device, such as a transseptal needle (having a narrow distal portion), will protrude from the hybrid dilator 100. The narrowest distal portion of a compatible puncture device will have an outer diameter less than ID3 to extend within the lumen 142 at this length S2 and beyond the distal edge 148, and typically a portion of the puncture device having an outer diameter greater than ID3 and less than ID2 will fit into the internal taper T2. Thus, the dimension of length S2 is important in determining the distance that a puncture device will protrude from the hybrid dilator 1. In some such embodiments, this allows the hybrid dilator 100 to meet the same standards as existing transseptal dilators in terms of controlling the distance a transseptal needle can protrude when fully inserted. Additionally, as previously described, the distal tip 140 provides an external taper T3 that allows the dilator OD to transition from a narrow OD2 at the most distal end or edge 148 of the distal tip 140 to a wider OD1 at its proximal edge 146. In some such embodiments, the hybrid dilator 100 has smooth lines and a smooth external taper T3 to facilitate a smooth transition across tissue. In some such instances, the hybrid dilator 100 functions to reduce the number of physical or geometric transitions or instrument transitions that may cause difficulties and / or tactile disturbances that may impede a physician's ability to complete a transseptal or other tissue traverse.

[0021] In a typical example, as shown in Figures 1A and 2A, the dilator shaft includes a distal tubing 121, which in some examples includes high density polyethylene (HDPE) tubing. In some such embodiments, the HDPE has a hardness of about 55 Shore D to about 70 Shore D, and in a specific example, the HDPE hardness is about 67 Shore D. In a typical embodiment, the distal tubing 121 includes a material that meets the functional requirements of a transseptal sheath / dilator kit. In some such examples, the distal tubing 121 includes a straight shaft that transitions to a curved distal end 130. The distal tip 140 includes a tapered tip having a smooth external taper T3 with a taper angle TA of about 5.5 degrees + / - 1 degree, and an internal shape that provides a controlled inner diameter (ID) to provide a predictable needle extension length. In some embodiments, the length of the external taper T3 ranges from about 0.4 inches (1 cm) to about 1 inch (2.5 cm). In some such examples, the taper length for the external taper T3 is equal to about 0.646 inches or about 1.6 cm. The distal tubing 121 has an inner diameter ID1 equal to about 0.109 inches (0.277 cm) and an outer diameter OD1 equal to about 0.166 inches (0.422 cm) along a proximal portion (or proximal length 123) of the distal tubing 121 that extends from the proximal hub 112 to the adjacent distal tip 140, as shown in FIG. 1A. In the example shown in FIG. 2A, the inner diameter of the distal tip 140 tapers from ID1 to a relatively smaller inner diameter ID2 along the internal taper T1. In one such embodiment, the taper length of the internal taper T1 is equal to about 0.22 inches (0.56 cm) and ID2 extends a distance S1 of about 0.100 inches (0.254 cm) and has a value equal to about 0.056 inches (0.142 cm). In some examples, the inner diameter further transitions from ID2 to a smaller inner diameter ID3 along the internal taper T2. In some embodiments, the distal portion of the distal tip (length S2) has a length of about 0.71 cm to about 0.74 cm, and in some more specific embodiments, has a length of about 0.721 cm to about 0.726 cm.In a specific example, taper T2 extends a distance equal to about 0.044 inches (0.112 cm), where ID3 is equal to about 0.034 inches (0.086 cm), and extends a length S2 of about 0.285 inches (0.724 cm). In some alternative embodiments, S1 is equal to zero, such that internal taper T1 and internal taper T2 are adjacent to one another, thereby providing a smooth transition of the inner diameter. Some alternative embodiments include a dilator shaft that substantially comprises low density polyethylene or polyetheretherketone, and some such embodiments of the dilator shaft have a hardness of about 40 Shore D to about 85 Shore D.

[0022] Some embodiments of dilator shafts constructed from relatively hard materials (e.g., HDPE) have an inner diameter ID1 of about 0.072 inches (0.18 cm) to about 0.11 inches (0.28 cm). Other embodiments of dilator shafts constructed from relatively soft materials (e.g., polyurethane, polyether block amide) have an inner diameter ID1 of about 0.050 inches (0.13 cm) to about 0.11 inches (0.28 cm). Polyether block amide (PEBA) is a thermoplastic elastomer (TPE) known under the trade names VESTAMID® E (Evonik Industries) and Pebax (Arkema).

[0023] In the example shown in FIG. 2A , having several internal transition stages, such as internal taper T1 and internal taper T2, allows the hybrid dilator 100 to dilate the tissue puncture site to a desired extent while at the same time reducing the wall thickness W of the distal tubing 121. pThe hybrid dilator ensures that it has an OD along its proximal length (OD1) that allows the tip to be maintained at a constant diameter to provide shaft stiffness and rigidity comparable to conventional sheath / dilator assemblies. The interior geometry of the distal tip 140, including the dual tapers T1 and T2 and inner diameter along the distal tip 140, provides for insertion of a puncture device such as a needle and the desired elongation of the needle tip. The interior geometry also provides for a wall thickness W at the distal edge 148 of the distal tip 140 to ensure transseptal puncture site traversal and trackability. Tip (FIG. 2B) is sufficiently thin. Furthermore, the dual tapers T1 and T2 ensure that a smooth transition is provided between the relatively wide inner diameter ID1 along the proximal portion of the distal tubing 121 and the relatively narrow inner diameter ID3 at the distal edge 148. In some embodiments, the inner diameter ID3 at the distal edge 148 is between about 0.33 inches (0.084 cm) and about 0.037 inches (0.094 cm), and the outer diameter of the distal edge 148 is between about 0.040 inches (0.10 cm) and about 0.055 inches (0.14 cm). In one specific example, the inner diameter ID3 of the distal edge 148 is equal to about 0.034 inches (0.086 cm) (FIG. 2B) and the outer diameter OD2 of the distal edge is equal to about 0.042 inches (0.107 cm).

[0024] In some embodiments, the taper angle TA may range from about 5 degrees to about 15 degrees. In some embodiments, the taper length of the external taper T3 may range from about 1.0 cm to about 1.6 cm. In some embodiments, the length of the external taper T3 may range from about 0.4 inches (1 cm) to about 1 inch (2.5 cm). In one example, the taper length of the external taper T3 may be about 1.0 cm and the taper angle TA may be about 15 degrees. In some embodiments, the wall thickness WTip at the distal edge 148 of the distal tip 140 is about four thousandths of an inch (0.010 cm) to about five thousandths of an inch (0.013 cm). The wall thickness W Tip is sufficient to maintain the mechanical integrity of the distal tip 140, while not being so thick as to make it difficult for the distal tip 140 to traverse a puncture site in tissue.

[0025] 2C, the distal tip 140 may include a single internal taper T1 as shown. As shown, the distal tubing 121 is shown with a visible lumen.

[0026] Wall thickness, bending stiffness, and torque As discussed above with respect to FIG. 2A, the hybrid dilator 100 is an HDPE dilator having an 8.5 French ID and a 12.5 French OD. The ID and OD are representative of the dimensions along the proximal length 123 of the distal tubing 121. Additionally, the wall thickness Wp along the proximal length 123 is about 25.5 thousandths of an inch (0.065 cm) to about 27.5 thousandths of an inch (0.070 cm). The bending stiffness of the example shown is about 3 N / mm and the torque is about 4.5 Ncm.

[0027] In an alternative embodiment, the hybrid dilator is a 12.5 French OD dilator with an 8.5 French ID. The wall thickness Wp along the proximal length 123 of the distal tubing 121 is about 32 thousandths of an inch (0.081 cm). The bending stiffness of a particular example is about 4 N / mm and the torque is about 5 Ncm.

[0028] In yet a further alternative, the hybrid dilator 100 is a 12.5 French OD dilator with a 4.5 French ID. The wall thickness Wp along the proximal length 123 of the distal tubing 121 is about 55 thousandths of an inch (0.140 cm). A particular example bending stiffness is about 5.5 N / mm and torque is about 7 Ncm. In another example, the hybrid dilator is a 15 French dilator with a wall thickness of less than about 26.5 thousandths of an inch (0.067 cm) to provide adequate stiffness.

[0029] In some embodiments, the HDPE hybrid expander 100 has an OD of 12.5F, which is about 0.162-0.166 inches (0.411-0.422 cm), an ID of 4.5-8.5F (about 0.056-0.115 inches or 0.142-0.292 cm), a wall thickness of about 0.025 inches to about 0.055 inches (about 0.064-0.140 cm), a stiffness of about 3.5-5.5 N / mm, and a torque transmission of about 4 to about 7 Ncm.

[0030] In an alternative embodiment, the dilator shaft is constructed substantially from HDPE and includes a 12.5 French OD (about 0.162 to 0.166 inches or about 0.411 to 0.422 cm), an 8.5 French ID (about 0.108 to 0.115 inches or about 0.274 to 0.2921 cm), and a wall thickness of about 23.5 to about 29 thousandths of an inch (0.06 cm). Such an embodiment may have a bending stiffness of about 2.5 to 3.5 N / mm, and a torque transmission of about 4 to about 4.5 Ncm.

[0031] In another alternative embodiment, the dilator shaft is HDPE and has a 12.5 French OD (about 0.162 inches to 0.166 inches or about 0.411 to 0.422 cm), a 7.5 French ID (about 0.095 inches to 0.102 inches or about 0.241 to 0.259 cm), and a wall thickness of about 0.03 to 0.036 inches (about 0.076 to 0.091 cm). The stiffness of such examples is about 3.5 to 4.5 N / mm, and the torque transmission is about 4.5 to about 5.5 Ncm. In some specific embodiments, the wall thickness is about 32 thousandths of an inch (0.081 cm).

[0032] Another alternative embodiment includes a dilator shaft constructed of HDPE having a 12.5 French OD (about 0.162 inches to 0.166 inches or about 0.411 to 0.422 cm), a 4.5 French ID (about 0.056 inches to 0.063 inches or about 0.142 to 0.160 cm), and a wall thickness of about 0.05 to 0.055 inches (0.127 to 0.140 cm). Typically, such embodiments have a bending stiffness of about 5 to 6 N / mm and a torque of about 6 to 7 Ncm. In some specific embodiments, the wall thickness is about 55 thousandths of an inch (0.140 cm).

[0033] In some embodiments of the invention, the torque may range from about 1.0 Ncm to about 7 Ncm over a length of about 50 cm. In some examples, the bending stiffness ranges from about 1.0 N / mm to about 5.5 N / mm over a span of 50 mm.

[0034] Surface Finish In some embodiments of the present invention, the distal tubing 121 may include different surface finishes to provide various amounts of friction along the outer surface. In some embodiments, the distal tubing 121 may be formed substantially from HDPE, as described above. Alternatively, the dilator may be formed from multiple layers of material or composites. In some such examples, the multiple layers may extend concentrically and longitudinally along the length of the distal tubing 121 in the form of multiple tubular layers. In one such example, the inner layer or tubing includes an extrusion of an outer layer of PEBAX (polyether block amide) with a HDPE or low density polyethylene (LDPE) core. This may provide a relatively smoother outer surface finish compared to HDPE. Additionally, the PEBAX tubing may be further provided with a smooth coating on the outer surface by a silicone coating disposed thereon.

[0035] Alternative Distal Tip Embodiments In an alternative embodiment of the invention, as shown in Figures 3A-3D, the distal tip 140 includes a modified taper. In one specific example, as shown in Figures 3A and 3B, the tapered distal tip 140 may include a second feature, such as a second surface modification 147, which creates a surface change, such as a second ridge 147a or a depression 147b, to more carefully bring the series of haptics of a standard sheath / dilator transseptal kit into line. The first tactile stimulus comes from a first / initial feature, such as a first surface modification 145, which may be a first ridge 145a represented by a transition stage between the tapered tip 140 and the proximal length 123 of the distal tubing 121. As described above, the second tactile stimulus comes from the second surface modification 147, for example, a second ridge 147a or a depression 147b.

[0036] Alternatively, as shown in FIG. 3C, the tapered distal tip 140 may include a smooth single external taper T3 with a single surface modification, such as a first surface modification 145 in the form of a first ridge 145a at the transition, as previously described. In a further alternative, there may be two or more external tapers along the outer surface. In a specific example, the distal tip 140 may have two external tapers: an external taper T4 and an external taper T5, as shown in FIG. 3D, where the first surface modification 145 and the second surface modification 147 are formed by a transition step forming a first ridge 145a and a second ridge 145b. These provide a tactile sensation during use of the hybrid dilator 100, for example, when navigating the septum. This tactile sensation mimics the sensation typically obtained from the transition in a standard transseptal kit that includes a standard dilator and sheath assembly. In some such examples, the internal taper may include internal tapers T1 and T2, as shown in FIG. 2A.

[0037] Alternative In alternative embodiments of the invention, the distal tip 140 may have a modified external taper T3. In some such examples, the shape of the external taper T3 may vary. As outlined above, the distal tip 140 may have an external surface modification along the external taper T3. The external taper T3 may include a second ridge 147a, and the external taper T3 may include a depression 147b. Alternatively, the external taper T3 may include a modified roughness.

[0038] In alternative embodiments, the ID of the distal tip 140, including the internal taper(s), is modified to accommodate a crossing / piercing device such as a needle (e.g., RF needle). Alternatively, the internal geometry may be modified to accommodate a crossing / piercing device such as a guidewire (e.g., RF guidewire). In some embodiments, the shaft distal tubing 121 comprises a single material. Alternatively, the shaft distal tubing 121 may comprise a composite material by co-extrusion or post-extrusion processing / layering. In some examples, the shaft distal tubing 121 includes a lubricious coating material along its outer surface. In some such examples, the chemistry and / or processing of the lubricious coating material is varied to provide a suitable coating. In some embodiments, materials may be used within the distal tubing 121 for coating according to those known in the art. In a further alternative of the present invention, the hybrid dilator 100 may include a forward facing port along the distal tip 140 to allow for fluid injection when a needle or guidewire is positioned within the hybrid dilator 100.

[0039] In some embodiments of the present invention, the hybrid dilator 100 is constructed to optimize the stiffness / torque response of the tubing, and the handle / hub 112 provides improved handling characteristics (discussed further herein below). In some embodiments, as previously indicated, the distal tip 140 comprises two external distal tapers. In some embodiments, an internal controlled shape may be provided in a variable configuration.

[0040] FIG. 8 is a cross-sectional view of the shaft and distal tip of a hybrid dilator of an alternative embodiment of the present invention, and FIG. 9 is an enlarged view of the distal tip of FIG. 8, where the dilator shaft has two or more layers and the tip is typically constructed from the same material as one of the shaft layers.

[0041] The hybrid dilator 700 of FIG. 8 has a shaft 702 that includes three layers, an inner layer 706, an outer layer 708, and a middle layer, a torque layer 704, to improve the torqueability of the device. There is a smooth interface between the device tip 720 and the shaft 702. The inner layer 706 is typically constructed from HDPE, and the outer layer 708 is typically constructed from Pebax or LDPE. Exemplary embodiments of the shaft 702 provide a mechanical response that is similar to transseptal sheaths and dilator sets commonly used by physicians today. The durometer of the Pebax may be selected to adjust the flexibility and pushability of the shaft. The torque layer is typically a braided material, and in alternative embodiments, the torque layer may be a stiff polymeric and / or metallic hypotube. Some further embodiments of the shaft 702 do not include the torque layer 704. The outer layer 708 is typically constructed from Pebax or LDPE, but in some alternative embodiments, is made from HDPE, all of which are compatible with lubricious coatings. Exemplary embodiments of the shaft 702 have an outer diameter at least the size of current transseptal sheaths (approximately 0.144 inches (0.366 cm)) to dilate the septum at least the same size as current sheaths, and have mechanical responses (including flexibility, pushability, and torqueability) comparable to those of current transseptal sheath and dilator pairs. Some embodiments of the shaft 702 have an outer diameter of 12.5F, from about 0.163 inches (0.414 cm) to about 0.166 inches (0.421 cm). Other embodiments of the shaft 702 have an outer diameter of 15F, from about 0.193 inches (0.490 cm) to about 0.205 inches (0.521 cm). Some embodiments of the shaft 702 with the torque layer 704 have a torque transmission of about 4 Ncm to about 8 Ncm, with one specific embodiment having a torque transmission of about 8.1 Ncm.

[0042] In embodiments that include a torque layer 704 between the inner and outer materials (HDPE and Pebax), the braid typically acts as a fastener between the inner and outer layers. Such embodiments may be manufactured using a reflow process in which the braided layer mechanically bonds the two materials together by fusing both the inner and outer layers to the braided layer. Some such embodiments have a stainless steel braid and provide a torque transmission of 8 Ncm.

[0043] FIG. 9 shows an embodiment of a tip 720 that is typically constructed of HDPE, but with approximately 20 to 50 percent of the distal tip constructed of BaSO4 for ease of imaging, and may alternatively be constructed of Pebax or any thermoplastic material. In some embodiments, approximately 40% of the tip 720 is constructed of BaSO4. Upon inspection, HDPE exhibits the advantageous property of being stiff enough not to be skived. The tip 720 of FIG. 9 includes an inner lumen 724, a distal edge 722, and a single external taper T3 for smooth expansion. The internal tapers T1 and T2 guide devices (e.g., guidewires, needles) from the shaft to the tip area and limit needle protrusion (for compatible needles) from the end of the dilator. The example shown includes two distal holes 726 for limiting vacuum and pressure formation when withdrawing the device, and alternative examples include different sizes, locations, number of holes, and configurations of holes. Other embodiments of the tip 720 include radiopaque features such as bands and coils made from radiopaque materials (eg, platinum, gold, tungsten, and / or barium sulfate filled polymers).

[0044] With further reference to FIG. 9, the inner diameter of the tip 720 transitions from the shaft ID to a smaller diameter that is compatible with commonly used devices (e.g., guidewires and needles) of 0.032 inches (0.081 cm) or 0.035 inches (0.089 cm). The length of the external taper T3 is typically 1.0 cm or longer, as shorter lengths may increase the transverse force or cause the tissue to be crossed more sharply, with some examples of the tip 720 having a taper length T3 up to 3 cm long. In some embodiments, the external taper length of the external taper T3 ranges from about 0.4 inches (1 cm) to about 1 inch (2.5 cm). The outer diameter of the tip 720 is typically as large as 0.055 inches (0.140 cm), or the force to advance through tissue may be greater than a typical transseptal dilator. As an example, if a device is 0.032 inch (0.081 cm) compliant and has an ID of approximately 0.034 inch (0.086 cm), constraining the tip OD to a maximum of 0.054 inch (0.137 cm) will allow it to glide easily through tissue.

[0045] In a specific embodiment of a hybrid dilator 700 shown in Figures 8 and 9, the shaft 702 has an outer diameter of 0.164 inches (0.417 cm) and an inner diameter of 0.072 inches (0.183 cm), the inner diameter of the tip 720 at the distal edge 722 is compatible with devices having an outer diameter of 0.032 inches (0.081 cm) or 0.035 inches (0.089 cm), the tip maximum OD is less than 0.055 inches (0.140 cm), the two side holes 726 have a diameter of about 0.012 inches (0.030 cm) to about 0.024 inches (0.061 cm), and the external taper T3 has a length of 1.6 cm. A typical dilator has a taper length of approximately 1 cm and a smaller diameter than the embodiment shown. To avoid the hybrid dilator 700 having a larger taper angle than a typical dilator (which would result in a larger transverse force), the hybrid dilator has an external taper T3 with a length of 1.6 cm consistent with this relatively large outer diameter. In some embodiments, the inner diameter of the tip 720 at the distal edge 722 is from about 0.033 inches (0.084 cm) to about 0.037 inches (0.094 cm) and the outer diameter of the tip 720 at the distal edge 722 is from about 0.040 inches (0.10 cm) to about 0.055 inches (0.14 cm).

[0046] Further alternative embodiments of the hybrid dilator 700 include an outer layer 708 of the shaft 702 that is made from a thermoplastic material for ease of manufacturing. Some examples have only one or more lumen tapers. Some further embodiments include an electrode configured to pierce at the tip so that one device can pierce, cross, and dilate.

[0047] Some embodiments include a shaft having an inner layer 706 made from HDPE and an outer layer 708 made from Pebax, where during manufacture of the device, the tip 720 and inner layer 706 are formed from the same extrusion of HDPE such that the tip 720 and inner layer 706 are continuous without any internal joints, eliminating the risk of a sharp needle passing through the dilator becoming caught at the joint between the dilator shaft 702 and the tip 720.

[0048] Proximal Hub The hybrid dilator 100 includes a handle defined at its proximal end by combination with a hybrid or proximal hub 112, as further shown in FIG. 4A. The proximal hub 112 includes a dilator hub 114 that is integrally formed with a sheath or sheath-like hub 116. FIG. 4A also includes a prior art dilator 650 inserted into a sheath 660, with dilator hub 652 and sheath hub 662 shown proximally, and dilator 650 extending distally from sheath 660. The sheath 660 and dilator 650 advance across the septum 505, while cardiac tissue is captured on the sheath 660. In contrast, the hybrid dilator 100 advances unimpeded across the septum 505. In some embodiments, such as those shown in FIGS. 4B-4C and 4F, the dilator hub 114 includes a luer hub or luer connector 115 and the sheath hub 116 includes an arm 117 that functions as a pseudo side port that provides the functional feel of a side port to indicate / direct the distal bow state. The arm 117 mimics a standard sheath side port without providing the fluid capabilities of a standard sheath side port. The proximal hub 112, by featuring an additional instrument hold, forms a larger hub / handle than a standard transseptal dilator hub, providing the physician with similar manipulation and expected tactile feedback, and also allows the arm 117 to indicate the direction of the distal bow state. In some instances, the arm 117 may be replaced with a functional side port if fluid capabilities are desired. In one specific example, the proximal hub 112 includes a custom insert molded HDPE hub with a luer connector 115 at the proximal end and haptic features (defined by side port arms 117) to indicate the surface of the distal curve and provide similar handling characteristics. In some such examples, the proximal end 110 has a luer taper to allow for connection of a medical syringe or drip. FIG. 4D shows an end view through the distal end of the proximal hub 112 showing a fitting 119 of the proximal hub 112 for connecting the proximal hub 112 to the distal tubing 121. In some such examples, the fitting 119 may include a strain relief.4E and 4G show cross-sectional views of the proximal hub 112 illustrating the internal configuration of the proximal hub 112, which may include features to facilitate the entry of other devices during use. In some such examples, the proximal hub 112 comprises HDPE.

[0049] The proximal hub 112 includes an outer diameter OD3 of 5.25 mm at its distal end, an inside angle IA of 40.0 degrees, and a proximal angle PA of 6.0 degrees, as shown in FIG. 4E. In the proximal hub 112, the proximal cylinder has an outer diameter OD5 of 6 mm, and an outer diameter OD4 of 7.37 mm at the luer connector at its proximal end, as shown in FIG. 4F. The distance D1 between the end point 117a and the opposing point 117b is 28.39 mm, and the distance D2 between the opposing point 117b and the central longitudinal axis of the proximal hub 112 is 6.49 mm. The proximal hub 112 has an inner diameter ID5 of 4.25 mm inside the hub proximal end 113a, an inner diameter ID6 of 3 mm at the innermost part of the lumen, an inner diameter ID7 at the narrowest part of the lumen, and an inner diameter ID8 of 4.12 mm at the hub distal end 113b of the hub, as shown in FIG. 4g. Other hub dimensions shown in FIG. 4G include hub location H1 (at the distal end of the proximal internal taper) 12.40 mm from the hub proximal end 113a, hub location H2 (at the proximal end of the distal internal taper) 31.83 mm from the hub proximal end 113a, hub location H3 (at the distal end of the distal internal taper) 33.75 mm from the hub proximal end 113a, and hub location H4 (at the distal end of the narrowest part of the lumen) 35 mm from the hub proximal end 113a.

[0050] Alternative Proximal Hub Embodiments In some embodiments, as shown in Figures 5A-5D, an alternative embodiment of the hybrid dilator 200 includes an improved proximal section 210. The hybrid dilator 200 includes a valved proximal hub 212, as shown in Figures 5A-5B, where the hub includes a valve 213 at its proximal end with a cap 220 to hold the valve in place. The valve 213 is provided as a hemostatic valve. In some examples, as shown in Figure 5B, the valved proximal hub 212 further includes additional features to guide devices into the valve 213. In some embodiments, the proximal hub 212 has an insertion guide 218 as a molded or external feature that works in cooperation with the valve to guide and regulate products inserted into the valve 213. In the particular example shown, the insertion guide 218 is provided proximal to the valve 213.

[0051] According to another embodiment of the invention, features are provided within the valved proximal hub 212 to allow devices to pass through the narrow passage of the shaft tubing. In certain cases, a funnel guide 222 is provided to guide and regulate the product being inserted into the shaft tubing and into the valve 213. The funnel guide is positioned distal to the valve 213. In some such instances, the funnel guide 222 is provided as a molded feature. In some embodiments, the funnel guide 222 is also configured to center the proximal end of the guidewire relative to the valve. This centering allows the proximal end of the guidewire to be guided as it is inserted into the distal tip of the device for device exchange purposes.

[0052] In a further alternative, as shown in FIG. 5D, the hybrid dilator 200 includes a proximal hub 212 housing a valve 213, e.g., a hemostatic valve, and further includes a side port port 217 to which a side port tubing 219 is attached, along with a stopcock 228 for flushing and providing suction.

[0053] In alternative embodiments of the present invention, the proximal hub 212 may include materials taken from the group consisting of pebax, HDPE, LDPE, and nylon, or combinations thereof, to achieve desired lubricity and handling characteristics.

[0054] In yet a further alternative, a proximal hub 112 with a Luer connector 115 according to ISO 594-1, -2 is shown in Figure 5E. Additionally, an arm 117 in the form of a simulated side port is provided to provide the expected manipulation and to align with the distal curvature. Additionally, the proximal hub 112 includes a strain relief 119b at its distal end, with distal tubing 121 extending distally from the strain relief 119b.

[0055] Alternative In some embodiments of the invention, the proximal hub 112 or valved proximal hub 212 may comprise a molded hub. In some embodiments, the proximal hub 112 or valved proximal hub 212 may comprise HDPE. Alternatively, other materials may be used. In some embodiments, the shape of the hub may be varied as appropriate. In alternative embodiments of the valved proximal hub 212, the valve material and / or shape may be varied as known in the art. In some such instances, the slit configuration and / or size may be varied to provide a suitable valve that meets the requirements of the procedure, such as a transseptal procedure. In yet a further alternative, the material of the side port tubing, as well as the ID and OD of the side port tubing, may be selected and / or varied as known to one of skill in the art. Similarly, in some instances, as shown in FIG. 5D where a stopcock is provided, the stopcock material may be varied as known in the art.

[0056] In yet a further alternative of the present invention, some embodiments of the hybrid dilator of the present invention can simplify transseptal crossing and also allow for co-use of an ablation catheter, should the need arise.

[0057] Another aspect of the invention is a kit for puncturing tissue including a crossing device having puncturing features and a hybrid dilator 100, where the dilator has a dilator shaft defining a lumen 122 for receiving the crossing device, the dilator shaft being structured to support the crossing device when the crossing device is used to effect puncture of tissue. The hybrid dilator also includes a distal tip 140 having an outer diameter that tapers substantially to the outer diameter of the crossing device to cooperate to provide a smooth profile as the hybrid dilator 100 is advanced over the crossing device through tissue. In some embodiments of the kit, the crossing device is a mechanical needle having a sharp tip, and in some other embodiments, the crossing device is configured to deliver energy to tissue.

[0058] Another aspect of the invention is a system for puncturing tissue, the system including a crossing device having a puncturing feature operable to deliver energy to the tissue, an electrosurgical generator operable to provide energy to the puncturing feature, and a hybrid dilator 100, the hybrid dilator having a dilator shaft defining a lumen 122 for receiving the crossing device and structured to support the crossing device when the crossing device is used to effect a puncture in tissue. The hybrid dilator also includes a distal tip 140 having an outer diameter that tapers substantially to the outer diameter of the crossing device to cooperate to provide a smooth profile as the hybrid dilator is advanced over the crossing device and through tissue.

[0059] Methods of performing transseptal surgery using the hybrid dilator of the present invention In accordance with the present invention, the method of the present invention provides for streamlining surgical workflow by providing a hybrid dilator that combines the functionality of conventional transseptal sheath and dilator assemblies. The hybrid dilator of the present invention allows for a reduction in the number of devices required to complete a transseptal procedure, thereby increasing surgical efficiency and reducing surgical time and complexity.

[0060] In such an instance, the method of the present invention avoids the drawbacks associated with conventional transseptal surgery. Figures 6A and 6B show an example of a method for performing such a conventional transseptal medical procedure 300. The method includes step 310 of entering into the right atrium 501 via the vasculature using a guidewire, step 320 of advancing a sheath 20 and a dilator 40 over the guidewire into the right atrium 501, where the sheath 20 and the dilator 40 form a sheath and dilator assembly 50, step 330 of exchanging the guidewire for a crossing device 60 including a puncture device 62, and step 340 of advancing the crossing device 60 with the dilator across the septum 505 to provide and dilate a transseptal puncture site 510. In step 340, the sheath 20 may get stuck at the sheath / dilator interface, and the transition between the sheath / dilator may affect the physician's ability to cross tissue in a predictable and repeatable manner. Sometimes the physician may not be able to cross all the way to the sheath (to get the sheath to span the septal puncture site because tissue would get caught at the sheath / dilator interface). If the physician is successful in step 350, the physician may be able to advance the sheath and dilator assembly 50 and crossing device 60 through the transseptal puncture site 510, allowing the transition of the sheath and dilator to cross the puncture site 510. In some such procedures, the physician may wish to use a relatively large delivery sheath (e.g., larger than the transseptal sheath 20) for a complex procedure, such as a cryoablation procedure, or a left atrial appendage closure / occlusion procedure, but knowing that they will not be able to cross with a larger delivery sheath, the physician will introduce a standard transseptal kit with a sheath and dilator as discussed in step 350 above, purely to cross and pre-dilate the septum. This three-piece kit underutilizes the three items (sheath, dilator, guidewire) that are only there for the short procedure by having to be discarded when removed for exchange. Removal of the sheath / dilator assembly and exchange with a larger delivery sheath is described further below.In method step 360, the crossing device 60 is exchanged for a guidewire 80, which includes removing the crossing device 60 and advancing the guidewire 80 into the left atrium 502, in step 370 the sheath and dilator assembly 50 is removed, and in step 380 one or more second devices 70, such as a relatively larger delivery sheath, are advanced over the guidewire 80 into the left atrium 502 to complete the desired procedure.

[0061] As outlined herein above, embodiments of the present invention provide an optimal transseptal procedure. According to the method of the present invention, as shown in FIG. 7A and FIG. 7B, an optimal method 400 is provided for performing a transseptal procedure. The method includes step 410 of entering into the right atrium via the vasculature using a guidewire, and step 420 of advancing a hybrid dilator 100 having a support shaft / cylinder over the guidewire into the right atrium 501, where the use of the hybrid dilator 100 reduces the number of elements that the physician is required to prepare / assemble and introduce into the patient's body from three to two. Instead of a sheath, dilator, and guidewire, the hybrid dilator 100 and guidewire may be used. The method further includes step 430 of exchanging the guidewire for a crossing device 60 including a puncture device 62 [in some embodiments of the present invention, the puncture device 62 may include a needle. In some such instances, the needle may be high frequency (RF) needle. Alternatively, the needle may include a mechanical needle. In another embodiment of the present invention, the puncture device 62 is high frequency(RF) guidewire] and, in step 440, advancing the crossing device and hybrid dilator across the septum 505 to provide a transseptal puncture site 510 and dilate the puncture site 510 to facilitate advancement of one or more second devices 70 through the transseptal puncture site. The hybrid dilator 100, which may be referred to as a boost dilator, is provided as a simplified tool. This hybrid dilator simplifies the workflow of the procedure by providing an integrated transseptal tool compared to a sheath and dilator (and can be used with a guidewire and needle as shown). The hybrid dilator 100 is provided as one / single oversized dilator and can allow the physician to more easily complete a transseptal or other tissue crossing by reducing the number of physical / geometric transitions and the number of instrument transitions or tactile disturbances during use. The hybrid dilator 100 reduces changes in the hybrid dilator 100 due to snagging at the transseptal puncture site by providing smooth lines and tapers to facilitate a smooth transition across tissue, which allows the hybrid dilator 100 to be more easily advanced across the septum. The method further provides for exchanging the crossing device 60 for the guidewire 80 and advancing the guidewire 80 into the left atrium, step 450, removing the hybrid dilator 100, step 360, and advancing one or more second devices over the guidewire 80 into the left atrium 502, step 470, to complete the desired procedure.

[0062] In cases where the physician wishes to use a larger delivery sheath for a difficult procedure (e.g., cryoablation or LAA occlusion) but knows that the sheath product cannot be crossed, the physician can then simply introduce the hybrid dilator 100 over the guidewire as discussed in step 420 using a single device to cross the septum and pre-dilatate. The hybrid dilator 100 and the original guidewire can then be removed for exchange, thus using only two products (the hybrid dilator 100 and the guidewire instead of a standard sheath, dilator, and guidewire kit). As such, the improved method further provides for simply removing the hybrid dilator 100 in steps 460 and 470, consuming less product in the process and allowing for exchange with a second device, such as a larger delivery sheath, for the complex procedure.

[0063] Another embodiment of the method uses a hybrid dilator 100 and a crossing device to puncture the septum 505 of the heart. This embodiment of the method includes the steps of (a) positioning the distal tip 140 of the hybrid dilator at a desired location on the septum, (b) using the hybrid dilator 100 to support a crossing device disposed within the lumen of the hybrid dilator as the crossing device advances beyond the distal tip of the hybrid dilator to puncture the septum, and (c) dilating the desired location by advancing the hybrid dilator over the crossing device. In some such embodiments, the crossing device is a mechanical needle, and step (b) further includes puncturing the septum by applying a force from the mechanical needle to the septum. In other embodiments, the crossing device is configured to deliver energy, and step (b) further includes puncturing the septum by supplying electrical energy to the crossing device. Some embodiments further include steps (d) of exchanging the crossing device for a guidewire and advancing the guidewire into the left atrium, (e) of removing the hybrid dilator, and (f) of advancing one or more second devices over the guidewire into the left atrium.

[0064] In some embodiments using a hybrid dilator and crossing device to puncture the septum of the heart, the crossing device is configured to deliver energy and the crossing device is further configured for use as a guidewire, and the method further includes the steps of (d) removing the hybrid dilator and typically (e) advancing one or more second devices over the crossing device into the left atrium. Further details of crossing devices suitable for delivering energy and for use as a guidewire are provided in International Application No. PCT / IB2013 / 060287, entitled "METHODS AND DEVICE FOR PUNCTURING TISSUE," which is incorporated herein by reference in its entirety.

[0065] Thus, according to embodiments of the present invention, a method is provided for streamlining surgical workflow by providing a hybrid dilator that combines the functionality of conventional transseptal sheath and dilator assemblies. The hybrid dilator of the present invention can reduce the number of devices required to complete a transseptal procedure, thereby increasing surgical efficiency and reducing surgical time and complexity.

[0066] The problem when transseptal puncture is performed using a crossing device supported by a sheath and dilator set that has a transition step on the tissue that may be obstructive when crossing the septum can be addressed by eliminating the transition step by using a hybrid dilator (as described herein) in place of the sheath and dilator set, where the hybrid dilator has the appropriate functionality (flexibility, pushability, torqueability, distal taper, etc.) to facilitate a smooth crossing.

[0067] The embodiment(s) of the invention described above are intended to be merely exemplary, and the scope of the invention is therefore intended to be limited solely by the appended claims.

[0068] It is to be understood that certain features of the invention, which 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, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.

[0069] While the present invention has been described in conjunction with this specific embodiment, it is apparent that many alternatives, improvements, and modifications will become apparent to those skilled in the art. It is therefore intended to cover all such alternatives, improvements, and modifications that fall within the broad scope of the appended claims. All publications, patents, and patent applications mentioned in this specification are incorporated by reference in their entirety into this specification to the same extent as if each individual publication, patent, or patent application was specifically and individually intended to be incorporated by reference herein. Furthermore, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.

[0070] Some aspects of the present disclosure include: (1) 1. A hybrid dilator for use with a crossing device in a tissue puncture procedure, comprising: a dilator shaft defining an inner lumen for receiving a crossing device, the dilator shaft being structured to support the crossing device when the crossing device is used to effect a puncture in tissue; a distal tip having an outer diameter that tapers to an outer diameter of the crossing device to provide a smooth transition between the crossing device and the distal tip when the crossing device is inserted from the lumen and protrudes from the distal tip. 、 (2) The dilator shaft has an outer diameter of about 12 French to about 20 French. The above (1) The hybrid expander according to 、 (3) The dilator shaft has an outer diameter of about 0.414 cm to about 0.421 cm. The above (1) The hybrid expander according to 、 (4) The dilator shaft has an outer diameter of about 0.490 cm to about 0.521 cm. The above (1) The hybrid expander according to 、 (5) The dilator shaft comprises substantially high density polyethylene. The above (1) The hybrid expander according to 、 (6) The high density polyethylene has a hardness of about 55 Shore D to about 70 Shore D. (5) The hybrid expander according to 、 (7) The high density polyethylene has a hardness of about 67 Shore D. (5) The hybrid expander according to 、 (8) The dilator shaft defines an inner diameter of about 0.18 cm to about 0.28 cm. (5) The hybrid expander according to 、 (9) The dilator shaft comprises a material selected from the group consisting essentially of polyurethane and polyether block amide. The above (1) The hybrid expander according to 、 (10) The dilator shaft defines an inner diameter of about 0.13 cm to about 0.28 cm. (9) The hybrid expander according to 、 (11) The dilator shaft comprises a material selected from the group consisting essentially of low density polyethylene and polyetheretherketone. The above (1) The hybrid expander according to 、 (12) The dilator shaft has a hardness of about 40 Shore D to about 85 Shore D. (11) The hybrid expander according to 、 (13) The dilator shaft includes an outer layer comprised of a polyether block amide and an inner layer comprised of a material selected from the group consisting of low density polyethylene and high density polyethylene. The above (1) The hybrid expander according to 、 (14) The distal portion of the distal tip defines a distal inner diameter that is restricted to control the distance that a crossing device having a narrow distal portion protrudes from the hybrid dilator. The above (1) The hybrid expander according to 、 (15) The distal inner diameter is about 0.084 cm to about 0.094 cm. (14) The hybrid expander according to 、 (16) The distal inner diameter is about 0.086 cm. (14) The hybrid expander according to 、 (17) The distal portion of the distal tip has a length of about 0.71 cm to about 0.74 cm. The above (14) to (16) The hybrid expander according to any one of the claims 、 (18) The distal portion of the distal tip has a length of about 0.721 cm to about 0.726 cm. (17) The hybrid expander according to 、 (19) The distal portion of the distal tip has a length of about 0.724 cm. (18) The hybrid expander according to 、 (20) The distal edge of the distal tip has an outer diameter of about 0.10 cm to about 0.14 cm. (14) to (16) above The hybrid expander according to any one of the claims 、 (21) The distal tip includes an external taper having a taper angle of about 4.5 degrees to about 6.5 degrees. The above (1) The hybrid expander according to 、 (22) The distal tip includes an external taper having a taper angle of about 5 degrees to about 15 degrees. The above (1) A hybrid expander according to the present invention. (23) The external taper has a taper length of about 1.0 cm to about 1.6 cm. (21)Or (22) The hybrid expander according to 、 (24) The external taper has a taper length of about 1 cm to about 2.5 cm. (21) or (22) above The hybrid expander according to 、 (25) The distal tip includes an external taper having a taper length of about 1.0 cm and a taper angle of about 15 degrees. The above (1) The hybrid expander according to 、 (26) The distal edge of the distal tip defines an inner diameter of about 0.084 cm to about 0.094 cm. The above (1) The hybrid expander according to 、 (27) The distal edge has an outer diameter of about 0.10 cm to about 0.14 cm. (26) The hybrid expander according to 、 (28) The distal edge of the distal tip has a wall thickness of about 0.010 cm to about 0.013 cm. The above (1) The hybrid expander according to 、 (29) The proximal end of the distal tip has an inner diameter of about 0.277 cm and an outer diameter of about 0.422 cm, and the distal edge of the distal tip has an inner diameter of about 0.086 cm and an outer diameter of about 0.107 cm. The above (1) The hybrid expander according to 、 (30) The distal tip includes an indentation configured to provide a series of haptics. The above (1) The hybrid expander according to 、 (31) The distal tip includes two or more external tapers. The above (1) The hybrid expander according to 、 (32) The dilator shaft has an outer diameter of about 0.411 cm to about 0.422 cm and an inner diameter of about 0.142 cm to about 0.292 cm. (5)The hybrid expander according to 、 (33) The dilator shaft has a wall thickness of about 0.064 cm to about 0.140 cm. (32) The hybrid expander according to 、 (34) The dilator shaft has a stiffness of about 3.5 N / mm to about 5.5 N / mm. (33) The hybrid expander according to 、 (35) The dilator shaft has a torque transmission of about 4 N / cm to about 7 N / cm. (33) The hybrid expander according to claim 1 . (36) The dilator shaft has an outer diameter of about 0.411 cm to about 0.422 cm and an inner diameter of about 0.274 cm to about 0.292 cm. (5) The hybrid expander according to 、 (37) The dilator shaft has a wall thickness of about 0.06 cm to about 0.074 cm. (36) The hybrid expander according to 、 (38) The dilator shaft has a bending stiffness of about 2.5 N / mm to about 3.5 N / mm. (37) The hybrid expander according to 、 (39) The dilator shaft has a torque transmission of about 4 Ncm to about 4.5 Ncm. (37) The hybrid expander according to 、 (40) The dilator shaft has an outer diameter of about 0.411 cm to about 0.422 cm and an inner diameter of about 0.241 cm to about 0.259 cm. (5) The hybrid expander according to 、 (41) The dilator shaft has a wall thickness of about 0.076 cm to about 0.091 cm. (40) The hybrid expander according to 、 (42) The dilator shaft has a bending stiffness of about 3.5 N / mm to about 4.5 N / mm. (41) The hybrid expander according to 、 (43) The dilator shaft has a torque transmission of about 4.5 Ncm to about 5.5 Ncm. (41) The hybrid expander according to 、 (44) The dilator shaft has a wall thickness of about 0.081 cm. The above (40) to (43) The hybrid expander according to any one of the claims 、 (45) The dilator shaft has an outer diameter of about 0.411 cm to about 0.422 cm and an inner diameter of about 0.142 cm to about 0.160 cm. (5) The hybrid expander according to 、 (46) The dilator shaft has a wall thickness of about 0.127 cm to about 0.140 cm. (45) The hybrid expander according to 、 (47) The dilator shaft has a bending stiffness of about 5 N / mm to about 6 N / mm. (46) The hybrid expander according to 、 (48) The dilator shaft has a torque transmission of about 6 Ncm to about 7 Ncm. (46) The hybrid expander according to 、 (49) The dilator shaft has a wall thickness of about 0.140 cm. (45) to (48) above The hybrid expander according to any one of the claims 、 (50) The dilator shaft includes an inner layer, an outer layer, and a torque layer therebetween. The above (1) The hybrid expander according to 、 (51) The inner layer is made of high density polyethylene. (50)The hybrid expander according to 、 (52) The outer layer is comprised of a material selected from the group consisting of polyether block amide, low density polyethylene, and high density polyethylene. (50) The hybrid expander according to 、 (53) The torque layer is constructed from a braided material. The above (50) to (52) The hybrid expander according to any one of the claims 、 (54) The hybrid expander according to claim 53, wherein the braided material includes stainless steel. 、 (55) The torque layer is constructed from a stiff polymer. The above (50) to (52) The hybrid expander according to any one of the claims 、 (56) The torque layer is constructed from a metal hypotube. The above (50) to (52) The hybrid expander according to any one of the claims 、 (57) The dilator shaft has an outer diameter of about 0.414 cm to about 0.421 cm. The above (50) The hybrid expander according to 、 (58) The dilator shaft has an outer diameter of about 0.490 cm to about 0.521 cm. The above (50) The hybrid expander according to 、 (59) The distal tip includes an external taper having an external taper length of about 1 cm to about 2.5 cm. The above (50) The hybrid expander according to 、 (60) the distal tip includes a single external taper having a taper length of about 1.6 cm; The above (50) The hybrid expander according to 、 (61)The distal tip is constructed of high density polyethylene, with approximately 20 to 50 percent of the distal tip constructed of BaSO4 to facilitate imaging. The above (50) The hybrid expander according to 、 (62) Approximately 40% of the distal tip is composed of BaSO4 (61) The hybrid expander according to 、 (63) The distal edge of the distal tip has an inner diameter of about 0.084 cm to about 0.094 cm. Previous (57) Or (58) The hybrid expander according to 、 (64) The distal edge of the distal tip has an outer diameter of from 0.10 cm to about 0.14 cm. (63) The hybrid expander according to 、 (65) and further including a side hole having a diameter of about 0.030 cm to about 0.061 cm to limit vacuum and pressure formation when the device is withdrawn from said lumen. Previous (64) The hybrid expander according to 、 (66) the inner layer comprises high density polyethylene, the outer layer comprises polyether block amide, the distal tip comprises high density polyethylene, and the distal tip and the inner layer are substantially contiguous without any internal joints. (63) The hybrid expander according to 、 (67) The dilator shaft has a torque transmission of about 4 N / cm to about 8 N / cm. The above (50) to (52) The hybrid expander according to any one of the claims 、 (68) The dilator shaft has a torque transmission of about 8.1 Ncm. The above (50) to (52) The hybrid expander according to any one of the claims 、 (69)1. A method of using a hybrid dilator and crossing device to puncture a cardiac septum, comprising: (a) positioning a distal tip of the hybrid dilator at a desired location on the septum; (b) using the hybrid dilator to support a crossing device disposed within a lumen of the hybrid dilator as the crossing device advances beyond the distal tip of the hybrid dilator to puncture the septum; (c) dilating the desired location by advancing the hybrid dilator over the crossing device. 、 (70) The crossing device is a mechanical needle, and step (b) further comprises puncturing the septum by applying a force to the septum with the mechanical needle. Previous (69) The method according to 、 (71) The crossing device is configured to deliver energy, and step (b) further comprises puncturing the septum by supplying electrical energy to the crossing device. Previous (69) The method according to 、 (72) and (d) exchanging the crossing device for a guidewire and advancing the guidewire into the left atrium. (70) Or (71) The method according to 、 (73) and (e) removing the hybrid expander. Previous (72) The method according to 、 (74) and (f) advancing one or more second devices over the guidewire into the left atrium. Previous (73) The method according to 、 (75) The crossing device is configured for use as a guidewire, and the method further includes the step (d) of removing the hybrid dilator. Previous (71) The method according to、 (76) and (e) advancing one or more second devices over the crossing device into the left atrium. Previous (75) The method according to 、 (77) 1. A kit for puncturing tissue, comprising: a crossing device having a puncturing feature; a hybrid dilator including a dilator shaft defining an inner lumen for receiving the crossing device, the dilator shaft being structured to support the crossing device when the crossing device is used to effect a puncture in tissue, and a distal tip having an outer diameter that tapers substantially to an outer diameter of the crossing device to cooperate to provide a smooth profile as the hybrid dilator is advanced through tissue over the crossing device. 、 (78) The crossing device is a mechanical needle. Previous (77) The kit according to 、 (79) The crossing device is configured to deliver energy to tissue. Previous (77) The kit according to (80) 1. A kit for puncturing tissue, comprising: a crossing device having a puncturing feature; The above (1) to (16), (21), (22), (25) to (43), (45) to (48), (50) to (52), and (57) to (62). A kit comprising the hybrid expander described in any one of the above. 、 (81) The crossing device is a mechanical needle. (80) The kit according to 、 (82) The crossing device is configured to deliver energy to tissue. (80) The kit according to 、 (83) 1. A system for penetrating tissue, comprising: a crossing device having a puncture feature operable to deliver energy to tissue; and an electrosurgical generator operable to provide energy to the puncture feature; A system comprising: a hybrid dilator, the dilator shaft defining an inner lumen for receiving the crossing device, the dilator shaft being structured to support the crossing device when the crossing device is used to effect a puncture in tissue; and a hybrid dilator having a distal tip having an outer diameter that substantially tapers to an outer diameter of the crossing device to cooperate to provide a smooth profile as the hybrid dilator is advanced through tissue over the crossing device. 、 (84) 1. A system for penetrating tissue, comprising: a crossing device having a puncture feature operable to deliver energy to tissue; and an electrosurgical generator operable to provide energy to the puncture feature; The above (1) to (16), (21), (22), (25) to (43), (45) to (48), (50) to (52), and (57) to (62). A system comprising the hybrid expander according to any one of the preceding claims. 、 (85) The distal tip defines an inner diameter that tapers along a first internal taper. The above (1) Or (50) The hybrid expander according to 、 (86) The distal tip defines a second internal taper. Previous (85) The hybrid expander according to 、 (87) The first internal taper and the second internal taper are spaced apart. Previous (86) The hybrid expander according to ,and (88) The first internal taper and the second internal taper are adjacent to each other. Previous (86) The hybrid expander according to 、 It is.

Claims

1. 1. A hybrid dilator for use with a crossing device in a tissue puncture procedure, comprising: a dilator shaft defining an inner lumen for receiving a crossing device, the dilator shaft being structured to support the crossing device when the crossing device is used to effect a puncture in tissue; a distal tip located at the distal end of the dilator shaft, the distal tip having an outer diameter that tapers substantially in a distal direction to cooperate to provide a smooth transition between the crossing device and the distal tip such that a distal edge of the distal tip has an outer diameter slightly larger than an outer diameter of the crossing device when the crossing device is inserted from the lumen and protrudes beyond the distal tip; an inner diameter of the distal tip tapers distally along a first internal taper to a first reduced diameter toward the distal tip, and distal to the first internal taper, the first reduced diameter of the distal tip further tapers distally along a second internal taper to a second reduced diameter toward the distal tip; A hybrid dilator, wherein the distal tip has a constant inner diameter portion longitudinally disposed between the first internal taper and the second internal taper.

2. 10. The hybrid dilator of claim 1, wherein the first internal taper has a first taper angle and the second internal taper has a second taper angle.

3. The hybrid dilator of claim 1 , wherein the dilator shaft has an outer diameter of from about 12 French to about 20 French.

4. The hybrid dilator of claim 3 , wherein the dilator shaft comprises an inner layer, an outer layer, and a braided material therebetween.

5. The hybrid dilator of claim 4 , wherein the braided material comprises stainless steel.

6. 4. The hybrid dilator of claim 3, wherein the dilator shaft comprises an inner layer, an outer layer, and a stiff polymer therebetween.

7. The hybrid dilator of claim 3 , wherein the dilator shaft includes an inner layer, an outer layer, and a metallic hypotube therebetween.

8. 1. A kit for puncturing tissue, comprising: a crossing device having a puncturing feature; A kit comprising the hybrid expander of claim 1.

9. The kit of claim 8 , wherein the crossing device is a mechanical needle.

10. The kit of claim 8 , wherein the crossing device is configured to deliver energy to tissue.

11. 1. A system for penetrating tissue, comprising: a crossing device having a piercing feature operable to deliver energy to tissue; an electrosurgical generator operable to provide energy to the puncture feature; A system comprising: the hybrid expander of claim 1 .

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