Expandable introducer sheath with steering mechanism

Abstract

An expandable introducer sheath is disclosed that is provided with a steering mechanism. The introducer sheath (110) is configured for providing a percutaneous access for a prosthetic delivery system into a patient's vasculature. The introducer sheath includes a sheath member (102) that defines a central lumen (209) and has a longitudinally extending radially expandable portion. The sheath member further includes a steering wire (240) that is slidably disposed within a wall portion of the sheath member and extends longitudinally along the radially expandable portion. When the steering wire is in a relaxed configuration, the steering wire allows for an increase in the width of the radially expandable portion. When the steering wire is in a taut configuration, the steering wire allows for steering or bending of a distal portion of the sheath member to align a distal port of the introducer sheath, for example, with an orifice of a branch vessel.

Description

[0001] This invention patent application is a divisional application of the invention patent application with international application number PCT / US2017 / 023665, international application date of March 22, 2017, application number 201780019747.3 that entered the Chinese national phase, and entitled "Expandable Guide Sheath with Steering Mechanism".

[0002] Cross-references to related applications

[0003] This application claims priority to U.S. Patent Application No. 62 / 315,782, filed on March 31, 2016, the entire contents of which are incorporated herein by reference. Technical Field

[0004] The present invention relates to a guide sheath for providing percutaneous access to a transcatheter valve prosthesis delivery system into a patient's vascular system, and more specifically, to a manipulable guide sheath having an expandable portion for receiving a channel through which the transcatheter valve prosthesis delivery system passes. Background Technology

[0005] Guide sheaths provide percutaneous access to a patient's vascular system and are used to allow the introduction and positioning of various minimally invasive medical devices within the patient's vascular system. Minimally invasive medical devices specifically refer to any type of catheter sized for introduction into the vascular system to include transcatheter valve prosthesis delivery systems. Conventional guide sheaths comprise an elongated tubular component that defines the lumen, hub, and hemostatic valve of the guide sheath. Minimally invasive procedures are known to begin within the vascular system by first establishing a percutaneous entry point into a suitable vessel such as the femoral, brachial, or radial artery using a transfemoral puncture. Subsequently, the elongated tubular component of the guide sheath is partially inserted into the vascular system at the percutaneous entry point, where the clinician can access the proximal port of the guide sheath hub, allowing the minimally invasive medical device to be introduced into and advanced through the lumen of the guide sheath. In many minimally invasive surgeries within the vascular system, a guidewire can be first inserted through the guide sheath and then advanced through the vascular system (or, in some applications, through another body structure) to the treatment site.

[0006] A minimally invasive method has recently been developed to facilitate catheter-based implantation of prosthetic valves into a beating heart without the need for classic sternotomy and cardiopulmonary shunt procedures. More specifically, a flexible prosthetic valve supported by a stent structure has been developed for heart valve replacement. This flexible prosthetic valve can be delivered percutaneously using a catheter-based delivery system and may be referred to herein as a transcatheter valve or transcatheter heart valve prosthesis. Transcatheter heart valve prostheses may include a self-expanding or balloon-expandable stent structure with leaflets attached to the interior of the stent structure. They are configured to be reduced in diameter by being rolled onto a balloon catheter or contained within a sheath or outer tubular component of the delivery catheter before advancing through the vascular system of a vein or artery. Once the transcatheter heart valve prosthesis is positioned at the treatment site, for example, within a dysfunctional natural valve or a previously implanted prosthetic heart valve, the frame or stent structure can expand to securely hold the prosthetic heart valve in place.

[0007] The actual shape or construction of any specific transcatheter heart valve prosthesis to be delivered during transcatheter implantation surgery depends, at least in part, on the native heart valve to be replaced or repaired—namely, the mitral, tricuspid, aortic, or pulmonary valve. Because at least the distal portion of a catheter-based delivery system holds the prosthesis in a compressible configuration within that distal portion, most transcatheter heart valve prostheses have a relatively large delivery profile. To date, catheter-based delivery systems using this larger delivery profile require a larger diameter or size guide sheath to provide adequate clearance within its lumen to allow the catheter-based delivery system to pass through the patient's vascular system. However, a larger diameter or size guide sheath may only be suitable for patients with vessel sizes sufficient to accommodate such a guide sheath. To extend the applicability of transcatheter heart valve prostheses and their delivery systems with larger delivery profiles to patients with smaller vessel sizes, expandable guide sheaths with smaller diameters or sizes are configured to locally expand within the patient's vascular system to allow passage of prostheses and delivery systems described in U.S. Patent Application Publication No. 2014 / 0121629 by Macaulay et al. and U.S. Patent Application Publication No. 2014 / 0236122 by Anderson et al., each of which is incorporated herein by reference in its entirety. The localized radial expansion and subsequent retraction of segments of the expandable guide sheath described in the Macaulay and Anderson patent applications likely cause less trauma to the patient's vessels than the continuous longitudinal and radial expansion of a fixed, larger-diameter guide sheath.

[0008] An expandable guide sheath must be able to travel through the vascular system, and for certain procedures, clinicians may need to precisely manipulate or deflect the guide sheath so that its distal port or opening can be aligned with the orifice of a branch or lateral vessel. A pull cord is known to be attached to the distal portion of certain catheters and controlled by a proximal handle component. Using this mechanism, when the cord is pulled, the catheter deflects in the direction of the cord. However, the known pull cord mechanism is insufficient and inadequate for precise and controllable deflection of the expandable guide sheath because the radially expandable portion of the longitudinal extension of such a guide sheath lacks sufficient stiffness or column strength to respond reliably and / or uniformly.

[0009] In view of the above, there is a need for an expandable guide sheath with a steering mechanism that provides precise, safe and predictable deflection of the guide sheath as it travels through the anatomy of the vascular system. Summary of the Invention

[0010] This document provides an expandable guide sheath that offers a steering mechanism to allow precise positioning of the distal port of the guide sheath. The guide sheath is configured to provide a percutaneous access to a patient's vascular system for a prosthesis delivery system. The guide sheath includes a sheath component defining a central cavity and having a longitudinally extending radially expandable portion. The sheath component also includes a steering wire slidably disposed within the wall of the sheath component, the steering wire including a first segment and a second segment extending longitudinally along the radially expandable portion. When the steering wire is in a relaxed configuration, it allows for an increase in the width of the radially expandable portion. When the steering wire is in a taut configuration, it allows for manipulation or bending of the distal portion of the sheath component to align the distal port of the guide sheath, for example, with the orifice of a branch vessel.

[0011] In one embodiment, the steering wire in the taut configuration also prevents the radially expandable portion from expanding. In one embodiment, the steering wire includes a lateral segment that extends slidably within the sheath member across the distal end of the radially expandable portion. In one embodiment, a first segment of the steering wire extends parallel to a first side of the radially expandable portion, and a second segment of the steering wire extends parallel to an opposite second side of the radially expandable portion. Attached Figure Description

[0012] The foregoing and other features and advantages of the present invention will become apparent from the following description of embodiments of the invention illustrated in the accompanying drawings. The drawings, which are incorporated herein and form a part of this specification, further serve to illustrate the principles of the invention and to enable those skilled in the art to make and use the invention. These drawings are not drawn to scale.

[0013] Figure 1 A side view of a guide device according to an embodiment of the present invention is depicted.

[0014] Figure 2 A side view of a guide sheath according to an embodiment of the present invention is depicted.

[0015] Figure 2A and Figure 2AA It is along Figure 2 The AA line is cut off Figure 2 A cross-sectional view of the sheath component of the guide sheath, wherein, Figure 2A The sheath component is shown in its unexpanded state, while Figure 2AA The sheath component is shown in its extended state.

[0016] Figure 2 B is an embodiment of the present invention. Figure 2 The diagram shows a perspective view of region B of the guide sheath, in which only the filament structure of the sheath components is exposed for illustrative purposes.

[0017] Figure 2BB According to another embodiment of the present invention Figure 2 The diagram shows a perspective view of region B of the guide sheath, in which only the filament structure of the sheath components is exposed for illustrative purposes.

[0018] Figure 2C A cross-sectional view of a handle component according to an embodiment of the present invention is depicted.

[0019] Figure 2D Depicting Figure 2 A partial cross-sectional view of region D of the guide sheath shown.

[0020] Figure 3 An exemplary distal portion of a valve prosthesis delivery system used with a guide sheath according to this document is depicted.

[0021] Figure 4 Depicting Figure 3 The distal portion of the valve prosthesis delivery system, which is positioned in Figure 2 Within section B of the guide sheath.

[0022] Figure 5 A side view of the guide device 100 after being turned to a deflection state according to an embodiment of the present invention is depicted, wherein, Figure 3 The distal portion of the valve prosthesis delivery system extends distally from the guide device 100. Detailed Implementation

[0023] Specific embodiments of the invention will now be described with reference to the accompanying drawings, wherein the same reference numerals denote the same or functionally similar elements. The terms “distal” and “proximal” as used in the following description refer to the position or orientation relative to the clinician performing the treatment. “Distal” or “along the distal” means a position away from the clinician or along a direction away from the clinician. “Proximal” or “along the proximal” means a position close to the clinician or along a direction close to the clinician. The following detailed description is exemplary in nature only and is not intended to limit the invention or its application and uses. While the description of the invention is based on the background of heart valve treatment, the invention can also be used in endoscopic procedures, coronary procedures, or peripheral vascular procedures where deemed useful. Furthermore, it is not intended to be limited by any express or implied theory given in the foregoing technical field, background art, summary of the invention, or the following detailed description.

[0024] Figure 1 A guide device 100 according to an embodiment of the present invention is shown. The guide device 100 includes a guide sheath 110 and an expander 120. The guide sheath 110 has a sheath member 102 and a handle member 104 attached to a proximal end 106 of the sheath member 102. (See reference...) Figure 2 and Figure 2A The sheath component 102 is a tubular structure defining a central or internal cavity 209 extending from its proximal end 106 to its distal end 108, wherein the distal end 108 defines a distal port or opening 115 of the guide sheath 110. The handle component 104 includes a hemostatic valve (not shown), a proximal port 101, and a side port 103. By way of example, and not limitation, in Figure 1 The image shows a flushing tube 105 with a Luer connector 107, which is connected to a side port 103 of a handle assembly 104. A dilator 120 is configured to slide through a guide sheath 110, and more specifically, to be slidably disposed within a central cavity 209 of the sheath assembly 102, such that a distal portion 122 of the dilator 120 extends distally from a distal port 115 of the guide sheath 110.

[0025] To guide one or more minimally invasive medical devices to a treatment site within a patient, such as a valve prosthesis delivery system to a patient's dysfunctional heart valve, the clinician must first establish percutaneous access to the patient's vascular system. In a method of providing percutaneous access to a patient's vascular system according to the invention, given by way of example and not limitation, a puncture needle (not shown) may be inserted through the skin into a blood vessel, such as one of the femoral, brachial, or radial arteries. The puncture needle may then be slightly withdrawn until a trickle of blood appears, after which a guidewire (not shown) may be inserted through the puncture needle and advanced into the blood vessel. With the guidewire in place, a guide device 100 may be advanced over the puncture needle such that a dilator 120 widens the entry point into the blood vessel, and the sheath portion 102 of the guide sheath 110 obtains access to the blood vessel. The dilator 120 is then removed, leaving the sheath portion 102 of the guide sheath 110 in the blood vessel to keep the access open and to protect the blood vessel from trauma during the subsequent introduction of one or more minimally invasive medical devices for their passage.

[0026] This article refers to Figure 2 , Figure 2A , Figure 2AA , Figure 2 B. Figure 2BB , Figure 2C , Figure 2D , Figure 4 and Figure 5 The guide sheath 110 according to an embodiment of the present invention will be described in more detail below. Figure 2 This is a side view of the guide sheath 110 with the expander 120 removed. Figure 2A and Figure 2AA Each is along Figure 2 The cross-sectional view of the sheath component 102 of the guide sheath 110, taken by line AA, shows that... Figure 2A The sheath component 102 is shown in its unexpanded state, while Figure 2AA The sheath component 102 is shown in its extended state. Figure 2 B is Figure 2 The diagram shows a perspective view of section B of the guide sheath 102, wherein only the wire structure 212 according to an embodiment of the present invention is exposed for illustrative purposes. Figure 2BB This is according to another embodiment of the present invention. Figure 2 The diagram shows a perspective view of region B of the guide sheath, in which only the wire structure 212B of the sheath component is exposed for illustrative purposes.

[0027] Reference Figure 2A , Figure 2A and Figure 2B. The sheath component 102 includes a filament structure 212, an inner liner 214, and an outer cover 216, all interconnected to form the tubular wall of the sheath component. The inner liner 214 forms a circumferentially continuous inner layer 102a of the sheath component 102, while the outer cover 216 and the filament structure 212 can be considered to together form a circumferentially discontinuous outer layer 102b of the sheath component 102, wherein the filament structure 212 provides kink resistance and reinforcement to the sheath component 102. In an embodiment of the invention, the inner layer 102a of the sheath component 102 (formed by the inner liner 214) defines a longitudinally extending radially expandable portion 218 between a first longitudinally extending edge 211 and a second longitudinally extending edge 213 of the outer layer 102b of the sheath component 102 (formed by the outer cover 216 and the filament structure 212). In embodiments of the invention, the sheath component can be described as having a radially expandable portion extending longitudinally, such as an expandable portion 218 disposed between reinforcing portions, the expandable portion 218 being such as the remainder of the sheath component 102 formed by an outer cover 216 and an outer layer 102b of the filament structure 212 that is at least circumferentially discontinuous.

[0028] In embodiments of the present invention, the liner may be made of tetrafluoroethylene (TFE). It is formed of polytetrafluoroethylene (PTFE), polyethylene, polyethylene terephthalate (PET), or polyester. In one embodiment of the invention, the liner may have a low coefficient of friction on its inner surface to facilitate the advancement of one or more minimally invasive medical devices through the guide sheath according to an embodiment of the invention. In an embodiment of the invention, the outer sheath may be made of polyurethane (e.g., Elasthane TM , or The outer casing is formed and may include 20% barium sulfate added as a radiopaque agent. In other embodiments, the outer casing may be made of, for example, It is formed from a polyamide-polyether block copolymer such as nylon 12 or polyethylene. In other embodiments, the outer sheath may be loaded with tungsten or basic bismuth carbonate to increase radiation impermeability, thereby making the guide sheath according to embodiments of the invention radiation-detectable (radio-impermeable).

[0029] In embodiments of the invention, the wire structure may be formed of a shape memory material such as a nickel-titanium alloy (NiTiNO), wherein the diameter of the wire ranges, for example, from about 0.005 inches to about 0.02 inches. In other embodiments, the wire structure may be formed of an elastic material, such as a nickel-cobalt-chromium-molybdenum alloy (MP35N), stainless steel, high-spring tempered steel, or any other metal or composite with elastic properties, to allow the guide sheath according to embodiments of the invention to radially expand and retract.

[0030] In one embodiment of the invention, the filament structure 212 of the outer layer 102b of the sheath component 102 is formed of a shape memory or elastic material to actively retract or return the radially expandable portion 218 of the sheath component 102 to its initial unexpanded state (e.g., after the valve prosthesis delivery system passes through the radially expandable portion 218). Figure 2A (As shown in the cross-section). To illustrate this function, Figure 3 An exemplary distal portion of a valve prosthesis delivery system 350 is depicted, including a distal segment or encapsulation portion 352 within which a transcatheter heart valve prosthesis (not shown) can be held in a compressed delivery configuration. Figure 4 A distal segment 352 is depicted advancing distally within segment B of the guide sheath 110. Because the delivery profile of the compressed heart valve prosthesis is relatively large, the delivery profile (or outer diameter) of the distal segment 352 of the valve prosthesis delivery system 350 is wider or larger than the delivery profile (or outer diameter) of the remaining proximal segment 354 of the valve prosthesis delivery system 350. According to an embodiment of the invention, the guide sheath 110 is configured to expand radially as the distal segment 352 of the valve prosthesis delivery system 350 advances distally or is pushed through the guide sheath 110, wherein... Figure 4 The dashed arrow in the figure is used to indicate the distal movement DM of the valve prosthesis delivery system 350 relative to the guide sheath 110.

[0031] More specifically, refer to Figure 2A , Figure 2AA , Figure 3 and Figure 4 The radially expandable portion 218 of the sheath component 102 of the guide sheath 110 is configured to partially and temporarily extend or stretch from width W1 to width W2 to change or expand a region or segment 402B of the sheath component 102, within which the distal segment 352 of the valve prosthesis delivery system 350 is positioned as the valve prosthesis delivery system 350 advances distally relative to the guide sheath 110. When the radially expandable portion 218 of the sheath component 102 is width W1, the central cavity 209 of the sheath component 102 has a reduced first inner diameter D1 in all unexpanded regions or segments 402A, 402C (see...). Figure 2A and Figure 4 When the radially expandable portion 218 of the sheath component 102 is transformed into width W2 due to the distal section 352 being disposed therein, the central cavity 209 of the sheath component 102 has an extended second inner diameter D2 in the extended region or section 402B (see...). Figure 2AA and Figure 4It should be clear from this description that the extended region or segment 402B changes its longitudinal position along the sheath member 102 to correspond to the distal segment 352 continuously advancing distally through (and relative to) the guide sheath 110, such that Figure 4 The sections 402A, 402B, and 402C shown are intended to be positioned in an illustrative rather than restrictive manner.

[0032] By way of example and not limitation, a heart valve prosthesis delivery system suitable for use with a guide sheath according to embodiments of the present invention is described in more detail in the following patent documents: U.S. Patent Application Publication No. 2014 / 0364939, Deshmukh et al.; U.S. Patent No. 8,562,673, Yeung et al.; U.S. Patent No. 8,579,963, Tabor et al.; U.S. Patent No. 8,974,524, Yeung et al.; U.S. Patent No. 8,998,980, Shipley et al.; and U.S. Patent No. 9,149,358, Tabor et al., each of which is incorporated herein by reference in its entirety.

[0033] Reference Figure 2A and Figure 2 B, the longitudinal axis L of the wire structure 212 wound around the sheath component 102 AThe wire structure 212 is bent or folded into a C-shape, wherein the first set of bent portions 221 and the second set of bent portions 223 of the wire structure 212 are aligned with the corresponding first longitudinal extension edges 211 and second longitudinal extension edges 213 of the outer layer 102b of the sheath component 102. In one embodiment of the invention, illustratively and not restrictively, each of the bent portions 221, 223 has a corresponding eyelet 225, 227 formed or fixed to that bent portion, so the wire structure 212 can also be considered to define or include the first set of eyelets 225 and the second set of eyelets 227 aligned with the corresponding first longitudinal extension edges 211 and second longitudinal extension edges 213 of the outer layer 102b. In other embodiments, without departing from the scope of the invention, each of the other or third bent portions 221, 223 may have a corresponding eyelet 225, 227 formed on that bent portion. In other embodiments, without departing from the scope of the invention, only one or more continuous or discontinuous bends 221, 223 provided along the farthest portion of the sheath member 102 may have corresponding eyelets 225, 227 formed on the bends. When the inner layer 102a and the outer layer 102b are joined together during the formation of the sheath member 102, at least a first set of eyelets 225 and a second set of eyelets 227 of the filament structure 212 are disposed within corresponding longitudinally extending channels or recesses 228a, 228b, wherein the longitudinally extending channels or recesses 228a, 228b are formed within the outer layer 102b. The longitudinally extending channels 228a, 228b extend substantially parallel to the corresponding first longitudinally extending edge 211 and second longitudinally extending edge 213 of the outer layer 102b, and extend substantially parallel to the corresponding first longitudinally extending side 231 and second longitudinally extending side 233 of the radially expandable portion 218. The first side 231 and the second side 233 will also be described herein as opposite sides 231, 233 of the radially expandable portion 218.

[0034] In reference Figure 2A and Figure 2BB In another embodiment, the first bent portion 221B and the second set of bent portions 223B of the filament structure 212B, which are aligned with the corresponding first longitudinal extending edge 211 and second longitudinal extending edge 213 of the outer layer 102b of the sheath member 102, do not include eyelets. In this embodiment, when the inner layer 102a and the outer layer 102b are joined together during the formation of the sheath member 102, at least the first set of bent portions 221B and the second set of bent portions 223B of the filament structure 212B are disposed within corresponding longitudinal extending channels 228a, 228b, wherein the longitudinal extending channels 228a, 228b are formed within the outer layer 102b.

[0035] Referring to one or more of the foregoing figures, a steering mechanism for precise, safe, and predictable deflection of the sheath component 102 providing the guide sheath 110 will now be described. The steering mechanism includes a steering cable 240 operatively coupled to a rotatable knob 242 of a handle component 104. Generally, the steering cable 240 extends from the handle component 104 to the distal end 108 of the sheath component 102 and is slidably disposed within longitudinally extending channels 228a, 228b formed within the outer layer 102b of the sheath component 102. The steering cable 240 can be described as having a first segment 240a slidably disposed within the longitudinally extending channel 228a of the outer layer 102b, and extending longitudinally substantially parallel to the first side 231 of the expandable portion 218 between the distal end 108 of the sheath member 102 and the handle member 104. Similarly, the steering cable 240 can be described as having a second segment 240b slidably disposed within the longitudinally extending channel 228a of the outer layer 102b, and extending longitudinally substantially parallel to the second side 233 of the expandable portion 218 between the distal end 108 of the sheath member 102 and the handle member 104. In an embodiment of the invention, the steering wire 240 may further include a lateral segment 240c defined or extending between the distal end of the first segment 240a and the distal end of the second segment 240b, wherein at least a portion of the lateral segment 240c is slidably disposed on the proximal side of the expandable portion 218 of the sheath member 102, at the distal end 119 of the expandable portion 218. As used herein, "slidably" in the context of the first segment 240a and the second segment 240b of the steering wire 240 means along the longitudinal axis L of the guide sheath 110. A The longitudinal direction moves back and forth, while the "sliding" of the lateral section 240c of the steering wire 240 used in this article refers to its ability to move forward and backward relative to the longitudinal axis L of the guide sheath 110. A It moves back and forth roughly in a horizontal direction.

[0036] Figure 2D The sheath component 102 is depicted Figure 2 A partial cross-sectional view of region D, wherein the farthest portion of channel 228b is opened for illustrative purposes. In an embodiment according to the invention, as... Figure 2DAs shown, the second segment 240b of the steering wire 240 can slidably extend or pass through one or more second sets of eyelets 227 (or one or more second sets of bends 223) located within the channel 228b, specifically along the farthest portion of the sheath member 102. Similarly, although not shown in detail, the first segment 240a of the steering wire 240 can slidably extend or pass through one or more first sets of eyelets 225 (or one or more first sets of bends 221) located within the channel 228b, specifically along the farthest portion of the sheath member 102. According to an embodiment of the invention, at least the farthest portions of the first segment 240a and the second segment 240b of the steering wire 240 include one or more stops, bumps, or protrusions 246 disposed distal to the corresponding eyelets 225, 227 (or bends 221, 223). Figure 2D As shown, for the farthest portion of the second section 240b, the size of the stop 246 is set to be larger than the opening of the corresponding holes 225, 227 (or the bent portions 221, 223).

[0037] The spatial relationship between the stop 246 and the eyelets 225, 227 (or the bends 221 / 223) is configured to allow limited distal movement of the first segment 240a and the second segment 240b of the steering thread 240 relative to the eyelets 225, 227 (or the bends 221, 223) in the distal direction, thereby allowing the expandable portion 218 to expand. (Refer to...) Figure 2D More specifically, each stop 246a, 246b is disposed between corresponding proximal and distal orifices 227, and each stop 246a, 246b can advance a distal distance MD by sliding movement of the second segment 240b of the steering wire 240 before the second segment 240b of the steering wire 240 moves further distally by contacting the stop 246a, 246b with its corresponding distal orifice 227.

[0038] Additionally, during tracking of the sheath component within a vascular system, when the stop 246 engages with the corresponding proximal eyelets 225, 227 (or bends 221 / 223) of the stop 246 due to the first segment 240a and the second segment 240b of the steering cord 240 being pulled or tensioned proximally, the interaction between the stop and the distal end of the eyelet / bend is used to return or maintain the expandable portion 218 in an unexpanded state. As the first segment 240a and the second segment 240b of the steering cord 240 continue to be tensioned proximally, the distal portion 502 of the sheath assembly 102 can be bent or deflected by a corresponding bending force. Figure 5The deflection or bending state shown is wherein the bending force is applied by the stop 246 to the distal side or distal end of the corresponding hole or bending portion of the stop 246.

[0039] In embodiments of the invention, the first segment 240a, the second segment 240b, and the lateral segment 240c of the steering wire 240 may be formed from a single wire. In other embodiments of the invention, the first segment 240a, the second segment 240b, and / or the lateral segment 240c of the steering wire 240 may be formed from one or more wires connected together. In still other embodiments, the first segment 240a and the second segment 240b of the steering wire 240 may be separate and independent wires, and a lateral segment may not be provided between them. The steering wire according to embodiments of the invention may be formed from one or more wires of suitable stainless steel, nitinol, UHMWPE (ultra-high molecular weight polyethylene), and nylon.

[0040] Figure 2C A cross-sectional view of the handle component 104 is depicted, showing the proximal ends 244a, 244b of the steering wire 240, which are fixed inside the handle component 104 at positions 224a, 224b, such that the nearest side portions 246a, 246b of the first segment 240a and the second segment 240b of the steering wire 240 are disposed within the interior of the handle component 104. Furthermore, the nearest side portions 246a, 246b of the first segment 240a and the second segment 240b are operably connected to a rotatable knob 242, such that when the rotatable knob 242 is rotated or turned in a first direction, the nearest side portions 246a, 246b wind or rotate around a feature of the knob, thereby suspending the steering wire 240. When the steering cord 240 is in a taut configuration, the first section 240a and the second section 240b are tensioned in the proximal direction, and when sufficient tension or force is applied to the sheath assembly 102 via the interaction between the stop 246 of the steering cord 240 and the eyelets / bends of the cord structure 212, the distal portion 502 of the sheath assembly 102 will deflect or bend.

[0041] In this embodiment of the invention, the desired deflection Θ can be used as a guideline. D The amount of rotation of knob 242 along a first direction is selected, determined by radiographic imaging or other suitable imaging within the vascular system at the distal end 108 of sheath component 102. In this embodiment of the invention, the deflection Θ... D Is Figure 1 The longitudinal axis L of the sheath component 102 in its straightened, undeflected state is shown. A and Figure 5The central axis C of the deflection distal portion 502 of the sheath component 102 shown A The values ​​are measured between [specific measurements]. By way of example, and not limitation, a quarter turn of knob 242 may correspond to approximately 15° deflection, a half turn of knob 242 may correspond to approximately 30° deflection, and / or a three-quarter turn of knob 242 may correspond to approximately 45° deflection. In one embodiment, the rotatable knob 242 may be provided with markings to indicate when the knob is rotated in a first direction to a position corresponding to a deflection angle of the sheath member 102. For example, by way of example, and not limitation, a set of markings may be provided, wherein each marking corresponds to a corresponding angle of deflection of the sheath member 102 to 10°, 15°, 20°, 25°, etc. In one embodiment, the rotatable knob 242 may also have a locked or feed position in which the steering thread 240 is sufficiently taut to prevent the radially expandable portion 218 of the sheath member 102 from expanding and / or to help the radially expandable portion 218 return to an unexpanded state. In one embodiment, the sheath component 102 can be fixed in a deflected state when in the locked position. In another embodiment, when the rotatable knob 242 is rotated or turned in a second direction (opposite to the first direction), the nearest portions 246a, 246b unwind around the feature portion of the knob, so that the steering wire 240 is converted to a relaxed or loosened configuration. In one embodiment, the total length of the steering wire 240 is such that, in the relaxed configuration of the steering wire 240, the width of the radially expandable portion 218 of the sheath component 102 is sufficiently increased or widened to allow the passage of the aforementioned valve prosthesis delivery system 350.

[0042] To guide one or more minimally invasive medical devices to a treatment site within a patient, such as a valve prosthesis delivery system to a patient's dysfunctional heart valve, the clinician must first establish percutaneous access to the patient's vascular system. In a method of providing percutaneous access to a patient's vascular system according to the invention, given by way of example and not limitation, a puncture needle (not shown) may be inserted through the skin into a blood vessel, such as one of the femoral, brachial, or radial arteries. The puncture needle may then be slightly withdrawn until a trickle of blood appears, after which a guidewire (not shown) may be inserted through the puncture needle and advanced into the blood vessel. With the guidewire in place, a guide device 100 may be advanced over the puncture needle such that a dilator 120 widens the entry point into the blood vessel, thereby allowing the sheath portion 102 of the guide sheath 110 to enter the blood vessel. Subsequently, the dilator 120 is removed, leaving the sheath portion 102 of the guide sheath 110 in the blood vessel to keep the access open and to protect the blood vessel from trauma when subsequently introducing one or more minimally invasive medical devices through which they pass.

[0043] To align the distal port 115 of the guide sheath 110 with the orifice of a branch or lateral blood vessel, the rotatable knob 242 can be rotated to fully tension the steering wire 240, thereby bending the distal portion 502 of the sheath component 102 (as described above) to align the distal port 115 with the orifice.

[0044] Although various embodiments have been described above, it should be understood that they are given by way of illustration and example only, and not by way of limitation. Those skilled in the art will appreciate that various changes in form and detail may be made without departing from the spirit and scope of the invention. Therefore, the breadth and scope of the invention should not be limited by any of the exemplary embodiments described above, but should be defined only by the appended claims and their equivalents. It should also be understood that each feature of each embodiment discussed herein and each feature of each reference cited herein can be used in combination with features of any other embodiments. All patents and publications discussed herein are incorporated herein by reference in their entirety.

Claims

1. A guide sheath for providing a percutaneous access to a patient's vascular system via a prosthesis delivery system, the sheath comprising: Sheath component, the sheath component having a central cavity defined by its wall structure, the wall structure being composed of A circumferentially continuous inner layer, the circumferentially continuous inner layer having a radially expandable portion, and A circumferentially discontinuous outermost layer, connected to the circumferentially continuous inner layer, the circumferentially discontinuous outermost layer including a first longitudinally extending edge and a second longitudinally extending edge, the radially expandable portion of the circumferentially continuous inner layer being defined between the first longitudinally extending edge and the second longitudinally extending edge. What is formed; as well as A C-shaped filament structure, embedded in the outermost circumferentially discontinuous layer of the wall structure, provides kink resistance and reinforcement to the sheath component. In each of the unexpanded and expanded states of the sheath component, the radially expandable portion of the circumferentially continuous inner layer is disposed inside the first longitudinally extending edge and the second longitudinally extending edge of the circumferentially discontinuous outermost layer, and In both the unexpanded and expanded states of the sheath component, the first longitudinal extending edge and the second longitudinal extending edge of the outermost layer, which are circumferentially discontinuous, do not overlap.

2. The guide sheath as described in claim 1, wherein, When the sheath component is in an unexpanded state, a first distance is defined between the first longitudinally extending edge and the second longitudinally extending edge of the outermost layer of the circumferential discontinuity of the wall structure, and When the sheath component is in the extended state, a second distance is defined between the first longitudinally extending edge and the second longitudinally extending edge of the outermost layer of the circumferential discontinuity of the wall structure.

3. The guide sheath as described in claim 1, wherein, When the sheath component is in its unexpanded state, the radially expandable portion of the circumferentially continuous inner layer of the wall structure has a first width, and When the sheath component is in an extended state, the radially expandable portion of the circumferentially continuous inner layer of the wall structure has a second width greater than the first width.

4. The guide sheath as described in claim 3, wherein, When the radially expandable portion of the circumferentially continuous inner layer of the wall structure has the first width, the central cavity of the sheath component has a first diameter. Wherein, when the radially expandable portion of the circumferentially continuous inner layer of the wall structure has the second width, the central cavity of the sheath component has the second diameter, and Wherein, when at least the distal portion of the prosthesis delivery system passes through the central cavity, the central cavity of the sheath component expands from the first diameter to the second diameter.

5. The guide sheath as described in claim 1, wherein, The C-shaped filament structure is formed of shape memory or elastic material to allow the sheath component to return from the expanded state to the unexpanded state.

6. A guide sheath for providing a percutaneous access to a patient's vascular system via a prosthesis delivery system, comprising: A sheath component, the sheath component defining a central cavity and having a wall structure, the wall structure being composed of... The liner has a radially expandable portion, which has a first width when the sheath component is in an unexpanded state, and a second width greater than the first width when the sheath component is in an expanded state. An outer cover, connected to the inner liner, the outer cover including a first longitudinally extending edge and a second longitudinally extending edge, the radially expandable portion of the inner liner extending between the first longitudinally extending edge and the second longitudinally extending edge. What is formed; as well as A C-shaped filament structure, embedded within the outer casing of the wall structure, provides kink resistance and reinforcement to the sheath component. In each of the unexpanded and expanded states of the sheath component, the radially expandable portion of the liner is disposed inside the first longitudinally extending edge and the second longitudinally extending edge of the outer casing, and In both the unextended and extended states of the sheath component, the first and second longitudinally extending edges of the outer cover do not overlap.

7. The guide sheath as described in claim 6, wherein, When the radially expandable portion of the liner of the wall structure has the first width, the central cavity of the sheath component has a first diameter. Wherein, when the radially expandable portion of the liner of the wall structure has the second width, the central cavity of the sheath component has the second diameter, and Wherein, when at least the distal portion of the prosthesis delivery system passes through the central cavity, the central cavity of the sheath component expands from the first diameter to the second diameter.

8. The guide sheath as described in claim 6, wherein, When the sheath component is in an unexpanded state, a first distance is defined between the first longitudinally extending edge and the second longitudinally extending edge of the outer cover of the wall structure, and Wherein, when the sheath component is in the extended state, a second distance is defined between the first longitudinally extending edge and the second longitudinally extending edge of the outer cover of the wall structure.

9. The guide sheath as claimed in claim 6, wherein, The C-shaped filament structure is formed of shape memory or elastic material to allow the sheath component to return from the expanded state to the unexpanded state.

10. The guide sheath as claimed in claim 6, wherein, The liner forms a circumferentially continuous inner layer, and the outer cover forms a circumferentially discontinuous outermost layer.

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