The present invention is related to prosthetic heart valve replacement, and more particularly to devices, systems, and methods for transcatheter delivery of collapsible prosthetic heart valves.
Prosthetic heart valves that are collapsible to a relatively small circumferential size can be delivered into a patient less invasively than valves that are not collapsible. For example, a collapsible valve may be delivered into a patient via a tube-like delivery apparatus such as a catheter, a trocar, a laparoscopic instrument, or the like. This collapsibility can avoid the need for a more invasive procedure such as full open-chest, open-heart surgery.
Collapsible prosthetic heart valves typically take the form of a valve structure mounted on a stent. There are two types of stents on which the valve structures are ordinarily mounted: a self-expanding stent and a balloon-expandable stent. To place such valves into a delivery apparatus and ultimately into a patient, the valve must first be collapsed or crimped to reduce its circumferential size.
When a collapsed prosthetic valve has reached the desired implant site in the patient (e.g., at or near the annulus of the patient's heart valve that is to be replaced by the prosthetic valve), the prosthetic valve can be deployed or released from the delivery apparatus and re-expanded to full operating size. For balloon-expandable valves, this generally involves releasing the entire valve, assuring its proper location, and then expanding a balloon positioned within the valve stent. For self-expanding valves, on the other hand, the stent automatically expands as the sheath covering the valve is withdrawn.
Despite the various improvements that have been made to the collapsible prosthetic heart valve delivery process, conventional delivery devices, systems, and methods suffer from some shortcomings. For example, in conventional delivery devices for self-expanding valves, it may be difficult to introduce the delivery device into the body. Specifically, it may be difficult to simultaneously manipulate a delivery device and an introducer sheath while keeping the introducer sheath in the correct position.
There therefore is a need for further improvements to the devices, systems, and methods for transcatheter delivery of collapsible prosthetic heart valves, and in particular, the introduction of such prosthetic heart valves into the heart. Among other advantages, the present invention may address one or more of these needs.
In some embodiments, an introducer sheath includes a tubular cannula extending between a leading end and trailing end, the cannula defining a lumen therethrough, a first balloon disposed adjacent the leading end of the cannula, the first balloon being configured and arranged to dilate from a collapsed condition to an expanded condition, and an inflation port configured to receive an inflation medium to dilate the first balloon.
In some embodiments, a method of delivering a collapsible prosthetic heart valve includes piercing an insertion location of a patient's body, partially inserting an introducer sheath into the patient's body, the insertion sheath having (i) a tubular cannula extending between a leading end and trailing end, the cannula defining a lumen therethrough, (ii) a first balloon disposed adjacent the leading end of the cannula, the first balloon being configured and arranged to dilate from a collapsed condition to an expanded condition, and (iii) an inflation port configured to receive an inflation medium to dilate the first balloon, and dilating the first balloon inside the patient's body to prevent movement of the introducer sheath in at least one direction.
Various embodiments of the present invention will now be described with reference to the appended drawings. It is to be appreciated that these drawings depict only some embodiments of the invention and are therefore not to be considered limiting of its scope.
As used herein, the terms “proximal,” “distal,” “leading” and “trailing” are to be taken as relative to a user using the disclosed delivery devices. “Proximal” or “trailing end” are to be understood as relatively close to the user and “distal” or “leading end” are to be understood as relatively farther away from the clinician. Also, as used herein, the words “substantially,” “approximately,” “generally” and “about” are intended to mean that slight variations from absolute are included within the scope of the structure or process recited.
Referring now to
Inner shaft 26 may extend from operating handle 20 to atraumatic tip 14 of the delivery device, and may include a retainer 25 affixed thereto at a spaced distance from tip 14 and adapted to hold a collapsible prosthetic valve in compartment 23. Retainer 25 may have recesses 80 therein that are adapted to hold corresponding retention members of the valve. Inner shaft 26 may be made of a flexible material such as braided polyimide or polyetheretherketone (PEEK), for example. Using a material such as PEEK may improve the resistance of inner shaft 26 to kinking while catheter assembly 16 is tracking through the vasculature of a patient.
Distal sheath 24 surrounds inner shaft 26 and is slidable relative to the inner shaft such that it can selectively cover or uncover compartment 23. Distal sheath 24 is affixed at its proximal end to an outer shaft 22, the proximal end of which is connected to operating handle 20 in a manner to be described. Distal end 27 of distal sheath 24 abuts atraumatic tip 14 when the distal sheath is fully covering compartment 23, and is spaced apart from the atraumatic tip when compartment 23 is at least partially uncovered.
Operating handle 20 is adapted to control deployment of a prosthetic valve located in compartment 23 by permitting a user to selectively slide outer shaft 22 proximally or distally relative to inner shaft 26, thereby respectively uncovering or covering the compartment with distal sheath 24. Outer shaft 22 may be made of a flexible material such as nylon 11 or nylon 12, and it may have a round braid construction (i.e., round cross-section fibers braided together) or flat braid construction (i.e., rectangular cross-section fibers braided together), for example.
The proximal end of inner shaft 26 may be connected in a substantially fixed relationship to an outer housing 30 of operating handle 20, and the proximal end of the outer shaft 22 may be affixed to a carriage assembly 40 that is slidable along a longitudinal axis of the handle housing, such that a user can selectively slide the outer shaft relative to the inner shaft by sliding the carriage assembly relative to the housing. Operating handle 20 may further include a hemostasis valve 28 having an internal gasket adapted to create a seal between inner shaft 26 and the proximal end of outer shaft 22.
As shown, handle housing 30 includes a top portion 30a and a bottom portion 30b. Top and bottom portions 30a and 30b may be individual pieces joined to one another as shown in
Handle housing 30 further defines a pocket 37 that extends through top portion 30a and bottom portion 30b for receiving a deployment actuator 21. Pocket 37 is sized and shaped to receive deployment actuator 21 with minimal clearance, such that the location of deployment actuator remains substantially fixed relative to housing 30 as it is rotated. Deployment actuator 21 may be internally coupled to body portion 41 via a threaded shaft or other suitable connection such that rotation of the deployment actuator in one direction (either clockwise or counterclockwise) pulls the body portion 41 of carriage assembly 40 proximally through elongated space 34.
To use operating handle 20 to deploy a prosthetic valve that has been loaded into compartment 23 and covered by distal sheath 24, the user may rotate deployment actuator 21, causing carriage assembly 40 to slide proximally within elongated space 34 in housing 30. Because distal sheath 24 is affixed to outer shaft 22, which in turn is affixed to carriage assembly 40, and because inner shaft 26 is fixed to housing 30, sliding the carriage assembly proximally relative to the housing will retract the distal sheath proximally from compartment 23, thereby exposing and initiating deployment of the valve located therein.
Delivery device 10 may be used to implant a medical device such as a collapsible stent-supported prosthetic heart valve 100 having a stent 102 and a valve assembly 104 (
The expandable stent 102 of prosthetic heart valve 100 may be formed from biocompatible materials that are capable of self-expansion, such as, for example, shape memory alloys, such as the nickel-titanium alloy known as “nitinol,” or other suitable metals or polymers. Stent 102 extends in a length direction L1 from proximal or annulus end 110 to distal or aortic end 112, and includes annulus section 120 adjacent proximal end 110, transition section 121, and aortic section 122 adjacent distal end 112. Annulus section 120 has a relatively small cross-section in the expanded condition, while aortic section 122 has a relatively large cross-section in the expanded condition. Preferably, annulus section 120 is in the form of a cylinder having a substantially constant diameter along its length. Transition section 121 may taper outwardly from annulus section 120 to aortic section 122. Each of the sections of stent 102 includes a plurality of struts 130 forming cells 132 connected to one another in one or more annular rows around the stent. For example, as shown in
Stent 102 may include one or more retaining elements 134 at distal end 112 thereof, retaining elements 134 being sized and shaped to cooperate with female retaining structures (not shown) provided on a deployment device. The engagement of retaining elements 134 with the female retaining structures on the deployment device helps maintain prosthetic heart valve 100 in assembled relationship with the deployment device, minimizes longitudinal movement of the prosthetic heart valve relative to the deployment device during unsheathing or resheathing procedures, and helps prevent rotation of the prosthetic heart valve relative to the deployment device as the deployment device is advanced to the target location and the heart valve deployed.
Valve assembly 104 of prosthetic heart valve 100 preferably is positioned in annulus section 120 of stent 102 and secured to the stent. Valve assembly 104 includes cuff 136 and a plurality of leaflets 138 which collectively function as a one-way valve by coapting with one another. As a prosthetic aortic valve, valve 100 has three leaflets 138.
Although cuff 136 is shown in
Leaflets 138 may be attached along their belly portions to cells 132 of stent 102, with the commissure between adjacent leaflets 138 attached to a commissure feature 140. As can be seen in
Prosthetic heart valve 100 may be used to replace a native aortic valve, a surgical heart valve or a heart valve that has undergone a surgical procedure. Prosthetic heart valve 100 may be delivered to the desired site (e.g., near the native aortic annulus) using any suitable delivery device. During delivery, prosthetic heart valve 100 is disposed inside the delivery device in the collapsed condition. The delivery device may be introduced into a patient using a transfemoral, transapical, transseptal or any other percutaneous approach. Once the delivery device has reached the target site, the user may deploy prosthetic heart valve 100. Upon deployment, prosthetic heart valve 100 expands so that annulus section 120 is in secure engagement within the native aortic annulus. When prosthetic heart valve 100 is properly positioned inside the heart, it works as a one-way valve, allowing blood to flow from the left ventricle of the heart to the aorta, and preventing blood from flowing in the opposite direction.
As briefly discussed, several approaches are possible to introduce the delivery device into the patient. With a transfemoral approach, the delivery device is introduced into the transfemoral artery of the patient. With transaortic and transapical approaches, shorter paths are taken to the aortic valve through the patient's chest. In such cases, an introducer sheath may be useful to advance the delivery device to the target location.
Introducer sheath 300 further includes balloon 330 disposed adjacent leading end 304 and fixed at a predetermined distance x1 from leading end 304 along cannula 310. In at least some examples distance x1 is between approximately 1.0 mm and approximately 30.0 mm. Introducer sheath 300 further includes inflation port 332 disposed on hub 305 and inflation tube 334 extending between inflation port 332 and balloon 330. Inflation tube 334 may be in communication with the interior of balloon 330 and configured to deliver an inflation media to the interior of balloon 330 to expand the balloon from a collapsed condition to an expanded condition. In at least some examples, the inflation media includes a liquid, such as a saline solution, contrast media, or a bioabsorbable gas such as nitrogen. As shown in
As seen in
With introducer sheath 300 at the desired depth and position, inflation media may be introduced through the inflation port (not shown) through inflation tube 334 to dilate balloon 330. After balloon 330 expands, upper surface s1 of balloon 330 contacts a portion of the patient's heart tissue t1 adjacent puncture location P1 so that cannula 310 can no longer freely travel through puncture location P1 due to the increased diameter of balloon 330. Thus, though cannula 310 is pulled back toward the clinician, it does not travel any further once balloon 330 abuts puncture location P1, preventing the accidental removal of introducer sheath 300 during the procedure. Delivery device (not shown) may then be advanced through lumen 312 of introducer sheath 300 and the procedure may continue with introducer sheath 300 safely secured at the proper position. Upon completion of the procedure, balloon 330 may be deflated by removing the inflation medium (e.g., nitrogen), thereby reducing the diameter of the balloon 330 such that the balloon is capable of fitting through puncture location P1. Introducer sheath 300 may then be withdrawn.
In transapical applications, an incision is made in the heart at puncture location P2 adjacent left ventricle 590 to create an opening across heart wall 592. A dilator (not shown) having an increasing diameter may be used to widen the incision at puncture location P2. Guidewire 450 may be advanced from puncture location P2 toward native valve annulus 400. Introducer sheath 500 may then be advanced over guidewire 450 from puncture location P1 toward native valve annulus 400. Markings 514 may aid the clinician in determining the depth of cannula 510 with respect to native valve annulus 400.
With introducer sheath 500 at the desired depth and position, inflation media may be introduced through the inflation port (not shown) through the inflation tube (also not shown) to dilate balloon 530. After balloon 530 expands, cannula 510 can no longer freely travel through puncture location P2 due to the increased diameter of balloon 530. Thus, though cannula 510 is pulled back toward the clinician, it does not travel any further once balloon 530 abuts puncture location P2, preventing the accidental removal of introducer sheath 500 during the procedure. The procedure may then continue as desired. Upon completion of the procedure, balloon 530 may be deflated by removing the inflation medium (e.g., nitrogen), thereby reducing the diameter of the balloon 530 such that the balloon is capable of fitting through puncture location P2. Introducer sheath 500 may then be withdrawn.
In another example, shown in
It will be understood that various modification may be made to the disclosed embodiments without departing from the spirit of the disclosure. For example, introducer sheath may be used to introduce a delivery device into the heart for prosthetic heart valve replacement, or may be used to introduce devices for valve repair at any of the heart valve (e.g., aortic valve, mitral valve, pulmonary valve, tricuspid valve). Additionally, introducer sheath may be used to deliver instruments to repair other structures in the heart, such as the chordae tendineae, papillary muscles and the like. Introducer sheath may also be used to deliver embolism prevention devices and stents, grafts and other cardiovascular devices. Introducer sheath may also be used to introduce any other medical instruments or device into a patient's body in applications other than cardiovascular applications and may be useful in any bodily location where temporarily affixing a sheath a certain distance from body tissue is useful.
In some embodiments, an introducer sheath includes a tubular cannula extending between a leading end and trailing end, the cannula defining a lumen therethrough, a first balloon disposed adjacent the leading end of the cannula, the first balloon being configured and arranged to dilate from a collapsed condition to an expanded condition, and an inflation port configured to receive an inflation medium to dilate the first balloon.
In some examples, the sheath may include a plurality of spaced markings disposed on the abluminal surface of the cannula; and/or the first balloon may be configured to circumferentially dilate from a first diameter in the collapsed condition to a second diameter in the expanded condition; and/or the first diameter may be less than 0.039 inches greater than a diameter of the cannula; and/or the second diameter may be between approximately 0.273 inches and approximately 0.280 inches; and/or the first balloon may be disposed a distance of between approximately 1 mm (0.039 inches) and approximately 30 mm (1.181 inches) from the leading end of the cannula; and/or the sheath may further include a hollow hub coupled to the cannula, and wherein the inflation port is defined in the hub; and/or the sheath may further include an inflation tube extending between the port and the first balloon, the inflation tube being in communication with the inflation port and an interior of the first balloon; and/or the sheath may further include a hemostasis seal disposed within the hub and configured to prevent fluid flow therethrough; and/or the inflation medium may be saline; and/or the inflation medium may be nitrogen; and/or the hub may further define a flush port for receiving a solution to remove air and lubricate the lumen; and/or the solution may include saline; and/or the sheath may further include a second balloon disposed on the cannula and spaced from the first balloon by a predetermined distance, the second balloon being configured and arranged to dilate from a collapsed condition to an expanded condition having a third diameter; and/or the third diameter of the second balloon may be substantially equal to the second diameter of the first balloon; and/or the predetermined distance between the first balloon and the second balloon may be substantially equal to at least one of a thickness of an ascending aorta and a thickness of a left ventricle.
In some embodiments, a method of delivering a collapsible prosthetic heart valve includes piercing an insertion location of a patient's body, partially inserting an introducer sheath into the patient's body, the insertion sheath having (i) a tubular cannula extending between a leading end and trailing end, the cannula defining a lumen therethrough, (ii) a first balloon disposed adjacent the leading end of the cannula, the first balloon being configured and arranged to dilate from a collapsed condition to an expanded condition, and (iii) an inflation port configured to receive an inflation medium to dilate the first balloon, and dilating the first balloon inside the patient's body to prevent movement of the introducer sheath in at least one direction.
In some examples, the insertion location may be the ascending aorta; and/or the insertion location may be the left ventricle; and/or the method may further include deflating the first balloon prior to removing the introducer sheath from the patient's body.
It will be appreciated that the various dependent claims and the features set forth therein can be combined in different ways than presented in the initial claims. It will also be appreciated that the features described in connection with individual embodiments may be shared with others of the described embodiments.
The present application claims the benefit of the filing date of U.S. Provisional Patent Application No. 62/117,630 filed Feb. 18, 2015, the disclosure of which is hereby incorporated herein by reference.
Number | Date | Country | |
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62117630 | Feb 2015 | US |