Passively controlled expander

Abstract

The system used for transseptal transcatheter procedures has a proximal end, a tapered distal end, a preset curve, and a proximal portion extending between the proximal end and the preset curve. The inner member is configured to slide between a first position and a second position within the outer cannula and has a higher rigidity than the outer cannula. In the first position, the tapered distal end is positioned at approximately 90 degrees relative to the proximal portion, and in the second position, the tapered distal end is positioned at more than 90 degrees relative to the proximal portion. The control mechanism has a first portion connected to the outer cannula and a second portion connected to the inner member, and is configured to move the inner member between the first and second positions.

Description

[Technical Field]

[0001] The present invention generally relates to methods and devices that can be used in the body of a patient. More specifically, the present invention relates to apparatus for performing transseptal transverse procedures. [Background technology]

[0002] Currently, there are devices for creating puncture holes, channels, or perforations within the tissues located within a patient's body. One specific medical procedure in question is a transseptal transverse procedure to provide access to the left atrium of the heart, in which a physician may use a sheath and dilator to support a transverse, puncture, or penetrating device. In such a procedure, the puncture device forms an initial perforation through the atrial septum, and the dilator is advanced through the septal puncture hole to widen the opening so that a larger diameter device, such as a delivery sheath or therapeutic device, can be advanced into the left atrium. Improved devices and methods to facilitate access to the left atrium are still needed. [Overview of the project]

[0003] One aspect of the present disclosure relates to a system used for transseptal transverse procedures. The system includes an external cannula having a proximal end, a tapered distal end, a pre-set curve, and a proximal portion extending between the proximal end and the pre-set curve. The pre-set curve is configured to position the tapered distal end at approximately 90 degrees relative to the proximal portion.

[0004] The system has an inner member configured to slide between a first position and a second position within the outer cannula, the inner member having a bending stiffness higher than that of the outer cannula. In the first position, the tapered distal end is positioned at approximately 90 degrees with respect to the proximal end, and in the second position, the tapered distal end is positioned at more than 90 degrees with respect to the proximal end.

[0005] The system includes a control mechanism having a first portion connected to the proximal end of the outer cannula and a second portion connected to the proximal end of the inner member. The control mechanism is configured to move the inner member between the first position and the second position.

[0006] The system includes a through member. In some embodiments, the through member includes a distal high-frequency electrode. In some embodiments, the control mechanism includes a handle.

[0007] In some embodiments, the control mechanism includes a slider. In some embodiments, the slider forms part of a ratchet system configured to lock the inner member in a desired position within the outer cannula.

[0008] In some embodiments, the slider moves along a track having substantially the same length as the predetermined curved arc length. In some embodiments, the outer cannula is formed from one or more polymer and metallic materials.

[0009] In some embodiments, one or more markers are positioned on part of the outer cannula or the inner member. In some embodiments, the one or more markers are radiopaque.

[0010] In some embodiments, the outer cannula or the inner member includes reinforcing material. In some embodiments, the outer cannula has a capacity of 0.01 to 4.62 pounds per square inch (lbf / in). 2 The inner member has a bending rigidity in the range of 0.07 to 130.42 lbf / in². 2 It has rigidity within the range of [this].

[0011] In some embodiments, the inner member includes a chamfered or polished distal tip. In some embodiments, the inner member includes one or more slots or grooves to increase flexibility from the proximal end to the distal end.

[0012] Other aspects of the present disclosure relate to dilators used for transseptal transverse procedures. The dilator includes an external cannula having a proximal end, a tapered distal end, a pre-set curve, and a proximal portion extending between the proximal end and the pre-set curve.

[0013] The dilator includes an inner member configured to slide between a first position and a second position within the outer cannula. The inner member has greater rigidity than the outer cannula. In the first position, the tapered distal end is positioned at approximately 90 degrees relative to the proximal end, and in the second position, the tapered distal end is positioned at more than 90 degrees relative to the proximal end.

[0014] The dilator has a control mechanism comprising a first portion connected to the proximal end of the outer cannula and a second portion connected to the proximal end of the inner member. The control mechanism is configured to move the inner member between the first position and the second position.

[0015] In some embodiments, the predetermined curvature has an arc length in the range of 1 to 8 inches. In some embodiments, the preset curvature has a radius of curvature in the range of 2 to 5 inches.

[0016] Other aspects of the present disclosure relate to a method for performing a transseptal procedure. The method includes positioning an outer cannula having an internal stiffening member within the patient's right atrium. The method includes altering the shape of the outer cannula by withdrawing the internal stiffening member from a portion of the outer cannula. The distal end of the outer cannula is positioned against the transseptal septum, and a penetrating member is advanced through the internal stiffening member and the outer cannula. The transseptal septum is punctured by the penetrating member.

[0017] While multiple embodiments are disclosed, further other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description which shows and describes exemplary embodiments of the present invention. Therefore, the drawings and the detailed description should be regarded as being essentially exemplary and not restrictive.

[0018] Example 1 is a system used for transseptal crossing, comprising an outer cannula having a proximal end, a tapered distal end, a preset curvature, and a proximal portion extending between the proximal end and the preset curvature, wherein the preset curvature is configured to position the tapered distal end at about 90 degrees with respect to the proximal portion, an outer cannula, and an inner member configured to slide between a first position and a second position within the outer cannula, the inner member having a higher rigidity than the outer cannula, and at the first position, the tapered distal end is positioned at about 90 degrees with respect to the proximal portion, and at the second position, the tapered distal end is positioned at more than 90 degrees with respect to the proximal portion, an inner member.

[0019] Example 2 is the system of Example 1, further comprising a control mechanism having a first portion connected to the proximal end of the outer cannula and a second portion connected to the proximal end of the inner member, the control mechanism being configured to move the inner member between the first position and the second position.

[0020] Example 3 is the system described in Example 1 or 2, further comprising a penetrating member. Example 4 is the system described in Example 3, wherein the penetrating member includes a distal high-frequency electrode. Example 5 is the system described in any one of Examples 2 to 4, wherein the control mechanism includes a handle.

[0021] Example 6 is the system described in any one of Examples 2 to 5, wherein the control mechanism includes a slider. Example 7 is the system described in Example 6, wherein the slider forms part of a ratchet system configured to lock the inner member at a desired position within the outer cannula.

[0022] Example 8 is the system described in Example 6 or 7, wherein the slider moves along a track. Example 9 is the system described in Example 8, wherein the track has a length substantially the same as the arc length of the preset curvature.

[0023] Example 10 is the system described in any one of Examples 1 to 9, wherein the outer cannula is formed from one or more polymer and metal materials. Example 11 is the system described in any one of Examples 1 to 10, further comprising one or more markers disposed on a part of the outer cannula or the inner member.

[0024] Example 12 is the system described in Example 11, wherein the one or more markers are radiopaque. Example 13 is the system described in any one of Examples 1 to 12, wherein the outer cannula or the inner member includes a reinforcing material.

[0025] Example 14 is the system described in any one of Examples 1 to 13, wherein the outer cannula has a bending stiffness in the range of 0.01 - 4362 lbf / in 2 and the inner member has a bending stiffness in the range of 0.07 - 130.42 lbf / in 2

[0026] Example 15 is the system described in any one of Examples 1 to 14, wherein the inner member includes a chamfered or polished distal tip. ​Example 16 is a system used transseptal transverse, comprising: an outer cannula having a proximal end, a tapered distal end, a preset curve, and a proximal portion extending between the proximal end and the preset curve, wherein the preset curve is configured to position the tapered distal end at approximately 90 degrees with respect to the proximal portion; an inner member configured to slide between a first position and a second position within the outer cannula, wherein the inner member has a higher rigidity than the outer cannula, and in the first position, the tapered distal end is positioned at approximately 90 degrees with respect to the proximal portion, and in the second position, the tapered distal end is positioned at more than 90 degrees with respect to the proximal portion; and a control mechanism having a first portion connected to the proximal end of the outer cannula and a second portion connected to the proximal end of the inner member, wherein the control mechanism is configured to move the inner member between the first position and the second position.

[0027] Example 17 is the system described in Example 16, further comprising a through member. Example 18 is the system described in Example 17, wherein the through member includes a distal high-frequency electrode. Example 19 is the system described in Example 16, wherein the control mechanism includes a handle.

[0028] Example 20 is the system described in Example 16, wherein the control mechanism includes a slider. Example 21 is the system described in Example 20, wherein the slider forms part of a ratchet system configured to lock the inner member in a desired position within the outer cannula.

[0029] Example 22 is the system described in Example 20, wherein the slider moves along the track. Example 23 is the system described in Example 22, wherein the track has substantially the same length as the arc length of the preset curve.

[0030] Example 24 is the system described in Example 16, wherein the outer cannula is formed from one or more polymer materials and metal materials. Example 25 is the system described in Example 16, further comprising one or more markers disposed on a part of the outer cannula or the inner member.

[0031] Example 26 is the system described in Example 25, wherein the one or more markers are radiation-opaque. Example 27 is the system described in Example 16, wherein the outer cannula or the inner member includes a reinforcing material.

[0032] Example 28 is the system described in Example 16, wherein the outer cannula has a flexural rigidity in the range of 0.01 - 4.62 lbf / in 2 and a modulus of elasticity in the range of 1×10 7 to 1×10 9 Pa.

[0033] Example 29 is the system described in Example 16, wherein the inner member has a flexural rigidity in the range of 0.07 - 130.42 lbf / in 2 and a modulus of elasticity in the range of 3×10 9 to 5×10 11 Pa.

[0034] Example 30 is the system described in Example 16, wherein the inner member includes a chamfered or polished distal tip. Example 31 is the system described in Example 16, wherein the inner member includes one or more slots or grooves to increase flexibility from the proximal end to the distal end.

[0035] Example 32 is a dilator used transseptal, comprising: an outer cannula having a proximal end, a tapered distal end, a preset curve, and a proximal portion extending between the proximal end and the preset curve; an inner member configured to slide between a first position and a second position within the outer cannula, wherein the inner member has a higher rigidity than the outer cannula, and in the first position, the tapered distal end is positioned at approximately 90 degrees with respect to the proximal portion, and in the second position, the tapered distal end is positioned at more than 90 degrees with respect to the proximal portion; and a control mechanism having a first portion connected to the proximal end of the outer cannula and a second portion connected to the proximal end of the inner member, configured to move the inner member between the first position and the second position.

[0036] Example 33 is an expander as described in Example 32, wherein the preset curvature has an arc length in the range of 1 to 8 inches. Example 34 is an expander as described in Example 32, wherein the preset curvature has a radius of curvature in the range of 2 to 5 inches.

[0037] Example 35 is a method for performing a transseptal procedure, comprising the steps of: positioning an outer cannula having an inner stiffening member in the patient's right atrium; withdrawing the inner stiffening member from a portion of the outer cannula to change the shape of the outer cannula; positioning the distal end of the outer cannula against the septum of the transseptum; advancing a penetrating member through the inner stiffening member and the outer cannula; and puncturing the septum of the transseptum with the penetrating member. [Brief explanation of the drawing]

[0038] [Figure 1A] Figure 1A is a schematic diagram of a medical procedure performed inside a patient's heart using a transseptal access system according to an embodiment of this disclosure. [Figure 1B] Figure 1B is a schematic diagram of a medical procedure performed inside a patient's heart using a transseptal access system according to an embodiment of this disclosure. [Figure 1C] Figure 1C is a schematic diagram of a medical procedure performed inside a patient's heart using a transseptal access system according to an embodiment of this disclosure. [Figure 2] Figure 2 shows a system for transseptal access with an internal member retracted to the nearest position. [Figure 3] Figure 3 shows the transseptal access system of Figure 2, with the inner member advanced to its most distal position. [Figure 4A] Figure 4A shows a perspective view of the mechanism for moving the inner member forward and backward. [Figure 4B] Figure 4B shows a partial cross-sectional view of the mechanism for moving the inner member forward and backward. [Figure 5] Figure 5 shows several curves that can be achieved by moving the inner member between the nearest and farthest positions. [Figure 6A] Figure 6A shows an exemplary configuration of the inner member. [Figure 6B] Figure 6B shows an exemplary configuration of the distal tip of the inner member. [Figure 7] Figure 7 shows the system in Figure 2 in the first configuration as part of a transseptal access procedure. [Figure 8] Figure 8 shows the system of Figure 2 in a second configuration in a part of transseptal access procedures. [Figure 9] Figure 9 shows another embodiment of a transseptal access system including a pre-curved inner member and a straight outer cannula. [Figure 10] Figure 10 shows another embodiment of a transseptal access system including a pre-curved outer cannula and a pre-curved inner member.

[0039] While the present invention is accommodating various modifications and alternative forms, specific embodiments are shown in the drawings as examples and are described in detail below. However, the intention is not to limit the present invention to the specific embodiments described. Rather, the present invention is intended to encompass all modifications, equivalents, and alternative forms that fall within the scope of the invention as defined by the appended claims. [Modes for carrying out the invention]

[0040] Figures 1A to 1C are schematic diagrams of a medical procedure 10 performed within a patient's heart 20 using a transseptal access system 50 according to an embodiment of the present disclosure. As is well known, the human heart 20 has four chambers: the right atrium 55, the left atrium 60, the right ventricle 65, and the left ventricle 70. The atrial septum 75 separates the right atrium 55 from the left atrium 60, and the ventricular septum 80 separates the right ventricle 65 from the left ventricle 70. As is also known, deoxygenated blood from the patient's body is returned to the right atrium 55 via the inferior vena cava (IVC) 85 or the superior vena cava (SVC) 90.

[0041] Various medical procedures have been developed to diagnose or treat physiological disorders occurring within the left atrium 60 and related structures. Exemplary such procedures include, but are not limited to, the deployment of a diagnostic or mapping catheter within the left atrium 60 for use in generating an electroanatomical map or diagnostic image of the left atrium 60. Other exemplary procedures include endocardial catheter-based ablation of target sites within cardiac chambers or adjacent vessels (e.g., pulmonary veins and their openings) to terminate cardiac arrhythmias such as atrial fibrillation and atrial flutter (e.g., radiofrequency ablation, pulsed-field ablation, cryoablation, laser ablation, radiofrequency ultrasound ablation, etc.). Further exemplary procedures may include the deployment of a left atrial appendage (LAA) closure device. Naturally, the foregoing examples of procedures within the left atrium 60 are merely illustrative and are not limiting in any way to the present disclosure.

[0042] The medical procedure 10 shown in Figures 1A–1C is an exemplary embodiment for providing access to the left atrium 60 using a transseptal access system 50 for the subsequent deployment of the aforementioned diagnostic and / or therapeutic devices within the left atrium 60. As shown in Figures 1A–1C, the target tissue site may be defined by the tissue of the atrial septum 75. In the illustrated embodiment, the target site is accessed via the IVC 85, for example, through the femoral vein, according to conventional catheter insertion techniques. In other embodiments, access to the target site of the atrial septum 75 may be achieved using an upward approach in which the transseptal access system 50 is advanced into the right atrium 55 via the SVC 90.

[0043] In the illustrated embodiment, the transseptal access system 50 includes an introducer sheath 100, a dilator 105 having a dilator body 107 and a tapered distal end 108, and a piercing device 110, also known as a penetrating device, configured to penetrate target tissue, such as the atrial septum 75. In the illustrated embodiment, the piercing device 110 is a radio frequency (RF) penetrating device having a distal end 112 terminating at a tip electrode 115. As shown, in the assembled and used configuration shown in Figures 1A–1C, the piercing device 110 may be located within the dilator 105, and the dilator 105 itself may be located within the sheath 100. In one embodiment in which the transseptal access system 50 is deployed into the right atrium 55 via the IVC 105, the user introduces a guidewire (not shown) into the femoral vein, typically the right femoral vein, and advances it toward the heart 20. The sheath 100 is then introduced into the femoral vein on the guidewire and advanced toward the heart 20. In one embodiment, the distal ends of the guidewire and sheath 100 are then positioned within the SVC 90. These steps may be performed using an imaging system (e.g., fluoroscopy or ultrasound imaging). Next, the dilator 105 is introduced into the sheath 100 and advanced into the SVC 90 on the guidewire and through the sheath 100. Alternatively, the dilator 105 may be fully inserted into the sheath 100 before entering the body, and both may be advanced simultaneously toward the heart 20. Once the guidewire, sheath 100, and dilator 105 are positioned within the superior vena cava, the guidewire is removed from the body, and the sheath 100 and dilator 105 are retracted so that their distal ends are positioned within the right atrium 55. Next, the described piercing device 110 may be introduced into the dilator 105 and advanced toward the heart 20.

[0044] Next, the user can position the distal end of the dilator 105 relative to the atrial septum 75, which may be done under imaging guidance. The puncture device 110 is then positioned so that the electrode 115 is aligned with the distal end of the dilator 105 or slightly protruding from it. The dilator 105 and puncture device 110 are dragged along the atrial septum 75 and can be positioned, for example, relative to the fossa ovalis of the atrial septum 75 under imaging guidance. Various additional steps may be performed, such as measuring one or more characteristics of the target site, e.g., electrographic or ECG (electrocardiogram) tracing and / or pressure measurement, or delivering material to the target site, e.g., delivering a contrast agent. Such steps may facilitate the positioning of the tip electrode 115 at the desired target site. In addition, tactile feedback provided by the medical puncture device 110 may be used to facilitate the positioning of the tip electrode 115 at the desired target site.

[0045] With the tip electrode 115 and expander 105 positioned at the target site, energy is delivered from an energy source (e.g., an RF generator) to the tip electrode 115 and the target site through the RF perforation device 20. In some embodiments, the energy is delivered with at least about 5W of power and at least about 75V (peak-to-peak) of voltage, which functions to vaporize cells near the tip electrode 115, thereby creating a void or perforation through the tissue at the target site. The user then applies force to the perforation device 110 to advance the tip electrode 115 at least partially through the perforation. In these embodiments, energy delivery is stopped when the tip electrode 115 has passed through the target tissue, i.e., when it has reached the left atrium 60. In some embodiments, the energy delivery step takes place over a period of about 1 second to about 5 seconds.

[0046] With the tip electrode 115 of the perforation device 110 crossing the atrial septum 75, the dilator 105 can be advanced forward, and the tapered distal tip 107 acts to gradually enlarge the perforation, allowing the distal end of the sheath 100 to advance into the left atrium 60.

[0047] In some embodiments, the distal end 112 of the puncture device 110 may be pre-formed to take on a non-traumatic shape, such as a J-shape, a pigtail shape (as shown in Figures 1B-1C), or other shape selected to orient the tip electrode 115 away from the endocardial surface of the left atrium 60. Examples of such RF puncture devices can be found, for example, in U.S. Patent Applications 16 / 445,790 and 16 / 346,404, assigned to Baylis Medical Company, Inc. The aforementioned pre-formed shapes may serve to the advantage of minimizing the risk of unintended contact between the tip electrode 115 and tissue within the left atrium 60, and may also act to anchor the distal end 112 within the left atrium 60 during subsequent treatment steps. For example, in embodiments, the puncture device 110 may be structurally configured to function as a delivery rail for the deployment of a relatively large bore therapeutic delivery sheath and associated dilator. In such embodiments, the dilator 105 and sheath 100 are withdrawn following the deployment of the distal end 112 of the perforation device into the left atrium 60. The pre-formed anchoring function of the distal end 112 prevents unintended retraction of the distal end 112 and the corresponding loss of access to the perforation site in the atrial septum 75 during such withdrawal.

[0048] This disclosure describes novel devices and methods for providing transseptal access to the left atrium 60. In some embodiments, the transseptal access system 50 may be configured to achieve a number of different curvatures. This is useful for introducing and positioning the system 50 at a desired location within the heart 20. For example, the different curvatures allow for the desired positioning of the dilator 105 and perforation device 110 along a portion of the atrial septum 75.

[0049] Those skilled in the art will understand that the piercing device 110 may take forms other than an RF piercing device. For example, embodiments of the present disclosure can easily accommodate mechanical piercing devices such as mechanical needles.

[0050] Figure 2 shows an embodiment of a transseptal access system 200 including a steerable expander 205, an inner member 220, and a handle. The expander 205 has a distal section 212 including a tapered distal end 212 and a proximal section 212 including a proximal end. The handle 230 is located at the proximal end of the expander 205. The handle 230 includes a slider 232 used to advance or retract the inner member 220 within the expander 205.

[0051] The dilator 205 is a hollow cannula configured to have a pre-formed or pre-set curve 207 when no force is applied. The pre-formed curve 207 may include a radius of curvature r in the range of 2 to 5 inches (50.8 to 127 mm) and an arc length 209 in the range of 1 to 8 inches (25.4 to 203.2 mm). In one embodiment, the pre-formed curve 207 positions the distal portion 212 of the dilator 205 at approximately 90 degrees from the proximal portion 214 of the dilator 205. The dilator 205 has a bending stiffness lower than the bending stiffness of the inner member 220 so that the shape of the dilator 205 changes as the inner member 220 is advanced within the dilator 205. The inner member 220 may be a hypotube or other hollow cannula having a lumen. The dilator 205 is rated at 0.01 to 4.62 lbf / in 2 Bending stiffness in the range of 1 × 10 7 ~1 × 10 9 The elastic modulus may be in the range of Pa. The inner member 220 has an elastic modulus of 0.07 to 130.42 lbf / in. 2 The rigidity within the range of 3×10 9 ~5×10 11 It may have an elastic modulus in the range of Pa.

[0052] The dilator 205 includes a tapered distal section 208 and a distal opening 210 through which a guide device, puncture device, or puncture device may extend. One or more markers 211 may be positioned on the dilator 205 to allow identification of the system 200 during a procedure using an imaging modality. For example, one or more markers 211 may be used to identify the tip or tapered section 208 of the dilator. In one embodiment, one or more markers 211 may include barium sulfate integral with the polymer forming the dilator wall.

[0053] System 200 is packaged as a kit and can be used immediately after being taken out of the package. Alternatively, the kit may include multiple expanders 205 having different pre-formed parts 207, and multiple internal members having varying degrees of rigidity.

[0054] Figure 3 shows the inner member 220 advanced to its furthest position within the expander 205. To position the inner member 220 at its furthest position, the slider 232 is advanced along the track 238 of the handle 230 to its furthest position. As shown in the figure, the pre-formed curve 207 is modified as a result of the more rigid inner member 220. While Figure 3 shows one configuration, it should be understood that the inner member 220 can be configured to be more rigid so that the pre-formed curve 207 takes on a completely linear position, or the inner member 220 can be configured to be less rigid so that the pre-formed curve 207 remains more curved.

[0055] Figure 4A illustrates a handle 230 for advancing and retracting the inner member 220. The handle 230 may include a substantially rectangular housing having a proximal end 237 and a distal end 231. The distal end 231 includes a connector 236 configured to be detachably attached to the proximal end 214 of the expander 205. In some embodiments, the handle 230 and the expander may be permanently connected.

[0056] The inner member 220 is configured to move within the expander 205 by the action of a slider 232. The slider 232 moves along a channel or track 238 formed in the handle 230. The length of the channel 238 is at least the same as the arc length 209 of the pre-formed curve 207. In some embodiments, the length of the channel 238 is substantially the same as the arc length 209 of the pre-formed curve 207.

[0057] The slider 232 includes a surface configured to contact a portion of the user's finger or thumb. In some embodiments, the slider 232 may include a textured or knurled surface 235 to increase friction between the slider 232 and the finger or thumb. The slider 232 includes a rectangular shape having a recess 241 into which a finger or thumb can be inserted. In other embodiments, the slider 232 may have a circular, elliptical, triangular, square, or other shape as desired.

[0058] As shown in Figure 4B, the slider 232 includes a portion 233 that extends into the handle 230 and is connected to an inner member 220. The inner member 220 may be permanently fixed to the portion 233 or may be detachably connected to it. In some embodiments, the portion 233 includes a series of ridges or teeth 239 configured to interact with a plurality of cavities 243 along a portion of the track 238 in the handle 230 in order to enable stepwise positioning of the slider 232. The slider 232 may be configured to selectively interact with the cavities 243 to set the slider 232 in a desired position along the track 238. This allows the inner member 220 to move to a desired position in the expander 205 and ultimately achieve the desired shape of the expander 205 by enabling the slider 232 to be unlocked and locked in a desired portion along the track 238.

[0059] As shown in Figure 4B, the slider 232 can be pushed down as indicated by arrow 252 and moved along the track as indicated by arrow 25 to retract or advance the inner member 220. Releasing the slider 232 allows the ridge or tooth 239 to seat in the cavity 243 and thus locks the slider 232 in place. Locking the inner member 220 against the expander 205 allows greater pressure to be applied to the expander 205 when traversing the septum 75 using the expander 205, without the inner member 220 sliding or displacing within the expander 205.

[0060] In some embodiments, a series of ridges or teeth 239 interacting with the cavity 243 provide tactile feedback to the user of the system 200. In some embodiments, the ridges or teeth 239 may be somewhat flexible, allowing the slider 232 to move along the track 238 without needing to be pressed down, but rigid enough to keep the slider 232 in place when the ridges or teeth 239 are within the cavity 243. Although not shown, the ridges or teeth 239 and the cavity may include at least one angled or inclined surface to facilitate relative translation with respect to each other.

[0061] As shown in Figure 4A, a series of surface markers 233 may be positioned on the handle 230 adjacent to the slider 232. The surface markers 233 may be configured to provide the user with an indication of the shape of the expander 205 as a result of the position of the slider 232 and, consequently, the inner member 220.

[0062] The proximal portion 237 of the handle 230 includes a connector 234 configured to allow selective connection to a desired medical device. In some embodiments, the connector 234 may include a Luer connector. The connector 234 may allow a fluid, such as a contrast agent, to be introduced into the expander 205. The connector 234 may also allow a guide member or a perforating or penetrating device, such as a high-frequency penetrating device, to be introduced into the expander 105. The inner member 220 has a lumen to allow the guide member or penetrating device to slide through the inner member 220 to the distal opening 210 of the expander 205.

[0063] The puncture or penetration device 110 may include a high-frequency electrode 115 at its distal tip. The penetration device may be connected to a high-frequency generator, which may be connected sequentially to one or more grounding pads, so that high-frequency energy can be delivered from the high-frequency generator to the high-frequency electrode 115. The penetration device 110 may include a core or wire connecting the generator to the electrode 115. When the electrode 115 is in contact with the septum 75, high-frequency energy may be supplied to the electrode 115 to initiate puncture of the septum 115 as described above. In other embodiments, the penetration device 110 may include a sharp tip and be advanced through the septum by force alone.

[0064] Figure 5 shows several shapes that can be created in the system 200 by moving the inner member 220 between the nearest and farthest positions within the expander 205. When the slider 232 of the handle is positioned in the nearest position, the inner member is fully extended from the preformed portion 207 of the expander 205. This allows the expander 205 to achieve the preformed curvature indicated by reference numeral 500 in Figure 5. When the slider 232 is in the nearest position, the distal tapered portion 208 of the expander may be positioned at approximately 90 degrees from the proximal portion 214 of the expander 205. In some embodiments, the distal tapered portion 208 of the expander may be positioned at more than 90 degrees from the proximal portion 214 or less than 90 degrees from the proximal portion 214.

[0065] When the handle slider 232 is positioned at its most distal location, the inner member 220 achieves its most distal position within the expander 205. In this configuration, the stiffness of the inner member 220 reduces the curvature 207 of the expander 205, resulting in the expander 205 achieving its most linear configuration, as illustrated in 508. It is understood that the shape of the curvature can be adjusted based on the stiffness of the inner member 220. For example, in some embodiments, when the slider 232 is positioned at its most distal location, a relatively stiff inner member 220 can completely overcome the force imparted by the pre-formed curvature 207, causing the expander 205 to be substantially linear. In contrast, a relatively flexible inner member 220 results in an expander 205 with a more pronounced curvature when the slider 232 is at its most distal location.

[0066] Figure 5 shows various shapes of the expander 502, 504, 506 when the handle slider is positioned between the farthest and nearest positions. Although only a limited number of shapes are shown, it is understood that the expander 205 can achieve a number of curvatures based on how far the inner member 220 is retracted from the expander 205.

[0067] In some embodiments, the expander 205 and / or inner member 220 may be formed from a polymer material, a metallic material, or a combination thereof. In embodiments, the inner member 220 may be formed from a material having superelastic properties and / or shape memory properties. One exemplary suitable metallic material is nickel-titanium (NiTi) alloy. The body of the expander 205 and / or inner member 220 may include regions having different stiffnesses or may be formed from different materials. For example, the proximal portion may be formed from a first, more rigid material, while the distal portion may be formed from a second, more flexible material.

[0068] In some embodiments, the inner member 220 may also include one or more markers along a portion thereof to identify the position or location of the inner member while using imaging. In some embodiments, the expander 205 and / or the inner member 220 may include a stiffening member such as a braid or coil. In some embodiments, only a portion of the expander 205 and / or the inner member 220, for example only the proximal portion, may include a stiffening member.

[0069] Figure 6A shows an exemplary configuration of an inner member 220 according to one embodiment of the present disclosure. The body of the inner member 220 has a number of notches 602, 604, 606 machined into the wall, for example by laser cutting. The shape and positioning of the notches allow for a transition of flexibility from the proximal to the distal 218 of the inner member. The notches may include a fracture helical configuration, as shown in 602, or may be positioned substantially perpendicular to the longitudinal axis, as shown in 604 and 606. In some embodiments, there may be a single notch winding around the axis such that the loop spacing is wider at the proximal end and even wider at the distal end. The spacing and size of the notches may be varied to achieve different flexibility along the inner member 220.

[0070] In some embodiments, the distal tip 218 of the inner member 220 may be sliced ​​or otherwise shaped so that the distal portion includes a chamfered portion 260 as shown in Figure 6B. This allows the tip of the inner member 220 to move more easily along the inner surface of the expander 205 within a pre-formed area. In other embodiments, the distal end of the inner member may be rounded and polished smooth to prevent any portion of the inner member from penetrating or gouging the wall of the expander 205.

[0071] In some embodiments, the inner member 220 may be formed from a shape memory material such as a shape memory polymer or shape memory metal. In this configuration, the inner member 220 may have a first shape at a first temperature and a second shape at a second temperature. More shapes of the expander 205 can be achieved by giving the inner member 220 its own curvature. Shape transitions can be initiated within the inner member 220 by inserting a heated solution into the expander 205 or by heating a portion of the inner member 220 using electricity.

[0072] Figure 7 shows the system 200 in a first configuration as part of a transseptal access procedure. As shown in Figure 7, the system is introduced into the patient's heart 20 through the inferior vena cava (IVC) 85. During insertion, the slider 232 of the handle 230 can be positioned at or near its distal position to substantially straighten the pre-formed curve 237 of the dilator 205 by advancing the medial member 220. Once the distal portion of the dilator 205 is positioned medially into the right atrium 55, the user may change the shape of the dilator 205, as shown in Figure 8, to position the tip of the dilator 205 in a desired position along the septum 75.

[0073] Figure 8 shows system 200 in a second configuration in part of a transseptal access procedure. During this part of the procedure, the user pulls out the inner member 220 from the dilator 205, allowing the pre-formed portion 207 of the dilator 205 to achieve its original shape. In this configuration, the distal end of the dilator 205 is positioned relative to the septum 75, and the penetrating device 110 can be inserted through the connector 234 of the handle 230 and guided to the distal tip of the dilator 205 to penetrate the septum 75.

[0074] Figures 7 and 8 show the inner members 220 at their nearest and most distal positions, respectively, but it is understood that the inner members 220 may be positioned at various locations within the dilator 205 for different parts of the procedure. By providing a dilator 205 capable of achieving a number of curvatures, users can adapt the system 200 for use in patients with varying heart sizes.

[0075] Figure 9 shows an exploded view of another embodiment of the trans-septal access system 900. Similar to the system described above, system 900 includes an expander 905 having a substantially linear configuration and an inner member 920 that includes a pre-formed curve 928 or a region that transitions to a curve via a shape-changing material. Similar to the system described above, the overall shape of system 900 is changed by moving the inner member 920 forward and backward within the expander 905.

[0076] The distal end 924 of the inner member 920 terminates with a rounded or polished distal tip 922 having an opening for receiving a guide member or through member. The proximal end 926 of the inner member 920 is detachably connected to the distal end 948 of the plunger 946 of the handle 942. The distal end 940 of the handle is configured to detachably connect to the proximal end 914 of the expander 905. The plunger 946 includes a hub 944, which can be grasped by a user to move the plunger 946 in and out of the handle 942, and thus to extend the inner member 920 into the expander 905 and to retract the inner member 920 from the expander 905.

[0077] Figure 10 shows another embodiment of the trans-septal access system 1000. In this embodiment, both the expander 1005 and the inner member 1020 include pre-formed curved regions 1007 and 1028, respectively. Since both the expander 1005 and the inner member 1020 include pre-formed curves, more complex shapes can be formed by moving the inner member 1020 within the expander 1005.

[0078] Similar to system 900, the distal end of the inner member 1020 terminates with a rounded or polished distal tip 1022 having an opening for receiving a guide member or through member. The proximal end 1026 of the inner member 1020 is detachably connected to the distal end 1048 of a plunger 1046 configured to move inside the handle 1042. The distal end 1040 of the handle is configured to detachably connect to the proximal end 1014 of the expander 1005. The plunger 1046 includes a hub 1044, which can be grasped by a user to move the plunger 1046 in and out of the handle 1042, and thus to extend the inner member 1020 into the expander 1005 and to retract the inner member 1020 from the expander 1005.

[0079] Various modifications and additions can be made to the exemplary embodiments described without departing from the scope of the present invention. For example, while the embodiments described above refer to specific features, the scope of the invention also includes embodiments having different combinations of features, and embodiments that do not include all of the described features. Accordingly, the scope of the invention is intended to encompass all such alternative forms, modifications, and variations included in the claims, along with all their equivalents.

Claims

1. A system used for transseptal crossing, An external cannula having a proximal end, a tapered distal end, a predetermined curve, and a proximal portion extending between the proximal end and the predetermined curve, wherein the predetermined curve is configured to position the tapered distal end at approximately 90 degrees relative to the proximal portion; An inner member configured to slide between a first position and a second position within the outer cannula, wherein the inner member has a higher rigidity than the outer cannula, and in the first position, the tapered distal end is positioned at approximately 90 degrees with respect to the proximal portion, and in the second position, the tapered distal end is positioned at more than 90 degrees with respect to the proximal portion. A system equipped with these features.

2. The control mechanism further comprises a first portion connected to the proximal end of the outer cannula and a second portion connected to the proximal end of the inner member, The system according to claim 1, wherein the control mechanism is configured to move the inner member between the first position and the second position.

3. The system according to claim 1 or 2, further comprising a through member.

4. The system according to claim 3, wherein the through member includes a distal high-frequency electrode.

5. The system according to any one of claims 2 to 4, wherein the control mechanism includes a handle.

6. The system according to any one of claims 2 to 5, wherein the control mechanism includes a slider.

7. The system according to claim 6, wherein the slider forms part of a ratchet system configured to lock the inner member to a desired position within the outer cannula.

8. The system according to claim 6 or 7, wherein the slider moves along the track.

9. The system according to claim 8, wherein the track has substantially the same length as the predetermined curved arc length.

10. The system according to any one of claims 1 to 9, wherein the outer cannula is formed from one or more polymer and metallic materials.

11. The system according to any one of claims 1 to 10, further comprising one or more markers disposed on part of the outer cannula or the inner member.

12. The system according to claim 11, wherein one or more markers are radiopaque.

13. The system according to any one of claims 1 to 12, wherein the outer cannula or the inner member includes a reinforcing material.

14. The aforementioned external cannula has a flow rate of 0.01 to 4362 lbf / in. ２ The inner member has a bending rigidity in the range of 0.07 to 130.42 lbf / in. ２ The system according to any one of claims 1 to 13, having bending rigidity in the range of [value].

15. The system according to any one of claims 1 to 14, wherein the inner member includes a chamfered or polished distal tip.

16. A system used for transseptal crossing, An external cannula having a proximal end, a tapered distal end, a predetermined curve, and a proximal portion extending between the proximal end and the predetermined curve, wherein the predetermined curve is configured to position the tapered distal end at approximately 90 degrees relative to the proximal portion; An inner member configured to slide between a first position and a second position within the outer cannula, wherein the inner member has a higher rigidity than the outer cannula, and in the first position, the tapered distal end is positioned at approximately 90 degrees with respect to the proximal portion, and in the second position, the tapered distal end is positioned at more than 90 degrees with respect to the proximal portion. A control mechanism having a first portion connected to the proximal end of the outer cannula and a second portion connected to the proximal end of the inner member, wherein the control mechanism is configured to move the inner member between the first position and the second position. A system equipped with these features.

17. The system according to claim 16, further comprising a through member.

18. The system according to claim 17, wherein the through member includes a distal high-frequency electrode.

19. The system according to claim 16, wherein the control mechanism includes a handle.

20. The system according to claim 16, wherein the control mechanism includes a slider.

21. The system according to claim 20, wherein the slider forms part of a ratchet system configured to lock the inner member in a desired position within the outer cannula.

22. The system according to claim 20, wherein the slider moves along the track.

23. The system according to claim 22, wherein the track has substantially the same length as the predetermined curved arc length.

24. The system according to claim 16, wherein the outer cannula is formed from one or more polymer materials and metal materials.

25. The system according to claim 16, further comprising one or more markers disposed on part of the outer cannula or the inner member.

26. The system according to claim 25, wherein one or more markers are radiopaque.

27. The system according to claim 16, wherein the outer cannula or the inner member includes a reinforcing material.

28. The aforementioned external cannula has a flow rate of 0.01 to 4.62 lbf / in. ２ Bending stiffness in the range of 1 × 10 ７ ~1 x 10 ９ The system according to claim 16, having an elastic modulus in the range of Pa.

29. The inner member has a density of 0.07 to 130.42 lbf / in. ２ Bending stiffness in the range of 3 × 10 ９ ~5 x 10 １１ The system according to claim 16, having an elastic modulus in the range of Pa.

30. The system according to claim 16, wherein the inner member includes a chamfered or polished distal tip.

31. The system according to claim 16, wherein the inner member includes one or more slots or grooves to increase flexibility from the proximal end to the distal end.

32. A dilator used for transseptal transverse, An outer cannula having a proximal end, a tapered distal end, a predetermined curve, and a proximal portion extending between the proximal end and the predetermined curve, An inner member configured to slide between a first position and a second position within the outer cannula, wherein the inner member has a higher rigidity than the outer cannula, and in the first position, the tapered distal end is positioned at approximately 90 degrees with respect to the proximal portion, and in the second position, the tapered distal end is positioned at more than 90 degrees with respect to the proximal portion. A control mechanism having a first portion connected to the proximal end of the outer cannula and a second portion connected to the proximal end of the inner member, wherein the control mechanism is configured to move the inner member between the first position and the second position. An expander equipped with the following features.

33. The expander according to claim 32, wherein the preset curvature has an arc length in the range of 1 to 8 inches.

34. The expander according to claim 32, wherein the preset curvature has a radius of curvature in the range of 2 to 5 inches.

35. A method for performing transseptal procedures, A step of positioning an outer cannula having an inner stiffening member within the patient's right atrium, A step of changing the shape of the outer cannula by pulling out the inner stiffening member from a part of the outer cannula, The steps include positioning the distal end of the lateral cannula against the septum of the transseptum, A step of advancing the through member through the inner stiffening member and the outer cannula, The process of puncturing the partition wall of the trans-septum with the aforementioned penetrating member, Methods that include...

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