Detailed Description
The present disclosure relates to systems, devices and methods for altering air flow to and from a region of a patient's lungs using an implantable device to reduce the volume of air trapped in a target region of the lungs and thereby enhance the elastic recoil performance of the remaining lung capacity.
The authors of the present invention herein conceived and disclosed implantable lung volume reduction devices, and medical techniques for implanting lung volume reduction devices through the trachea and bronchi using minimally invasive deployment methods, bronchoscopes, and surgical techniques. The device may be an intrabronchial valve, such as a one-way lobal valve.
The present invention may be an embodiment of providing innovative therapy to a patient suffering from pulmonary hyperinflation (e.g., emphysema, COPD, bronchitis, asthma) comprising implanting a lung volume reduction device into the respiratory tract of the patient's lung using a minimally invasive bronchoscopy technique. The implantable lung volume reduction devices disclosed herein may be generally referred to as "lung valves" and may be placed in the dry airways of the lung so that the single valve may regulate airflow to or from the entire lung and may have the benefit of a valve that was previously used for advanced intra-airway multi-valve placement trials. Benefits of a lung valve may include low cost, rapid procedure, ease of implantation, ease of removal, and more stable anchoring. However, the features of the devices disclosed herein may be innovative and may be used in the higher-level respiratory tract, and are not limited to devices that may be placed in the lobed trunk.
Anatomically, design content and challenges:
Fig. 1 is a schematic representation of certain anatomical features of the lung. Air may pass through the air tube 41, with the tube 41 bifurcated 42 into left and right main bronchi 43 and 60. The lungs are often visibly distinct, an anatomical partition known as the lobe. The right lung 55 is divided into three lobes, called the upper lobe 45, the middle lobe (not shown for simplicity) and the lower lobe 47, by the oblique slit 57 and the flat slit 58 into which the visceral pleura is folded. The left lung 56 is relatively small and is divided into an upper lobe 51 and a lower lobe 53 by an oblique slit 59. The term "proximal direction" refers to a direction along a path of the respiratory tract, toward the mouth or nose of a patient, and away from the lungs of the patient. In other words, the proximal direction is generally the same as the direction of exhalation during the patient's breathing. The term "proximal portion" or "proximal end" in reference to implantation of a device within the respiratory tract of a patient refers to the portion or end of the device that faces in the proximal direction. The term "distal direction" refers to a direction along a path of the respiratory tract, toward the patient's lungs, and away from the mouth or nose. The distal direction is generally the same as the direction of inspiration during the patient's breath. The term "distal portion" or "distal tip" as used in reference to implantation of a device within the respiratory tract of a patient refers to the portion or tip of the device that faces in the distal direction.
The lung valves 241, 300, 260, 350, 450, 480, 500 may be implanted in a secondary bronchi, also known as a lung lobal. Each lobe of a human has a lobe bronchi that delivers air, including three in the right lung and two in the left lung. The right lobar bronchi include a right superior lobar bronchi 44, a right middle lobar bronchi (not shown for simplicity), and a right inferior lobar bronchi 46. The left lobar bronchi include a left superior lobar bronchi 50 and a left inferior lobar bronchi 52. Overlapping cartilaginous plates in the lobular bronchi may provide structural support to maintain the patency of these bronchi. The average diameter of human lobar bronchi is around 8.3 mm and the average length is 19 mm (e.g., in the range of 15 to 30 mm).
The disclosed embodiments of the lung valves are designed to take into account delivery, ease of use and cost aspects.
The pulmonary valve may be delivered through a working channel of a bronchoscope. The pulmonary valve and delivery tool are sized to pass freely through the working channel of the bronchoscope. For example, one type of pulmonary valve that can be delivered through a working lumen having a diameter of 2.8 millimeters may have a maximum diameter of 2.6 millimeters (e.g., the maximum diameter may be 2.5,2.4,2.3,2.2,2.1 millimeters). In some embodiments, the lung valve may include a structural frame having a delivery state and a deployment state, wherein the delivery state has a maximum diameter in the range of 2 (0.0787) to 2.5 millimeters (0.0984 inches), preferably 2.11 millimeters (0.083 inches), and the unconstrained deployment state has a maximum diameter in the range of 10.16 (0.4) to 14 millimeters (0.551 inches), preferably 12.42 millimeters (0.489 inches), so as to be placed in a lung bronchus having an average diameter in the range of 7 to 12 millimeters. For example, the ratio of the maximum outer diameter in the unconstrained state to the maximum outer diameter in the converging delivery state may be in the range of 4:1 to 7:1, e.g., 5.45:1. Due to the relatively large diameter and short length of the lung bronchi, the aspect ratio of the lung valve in its deployed unconstrained state may be smaller than in current devices, and thus may be deployed at a more distal location. For example, a lung valve in its unconstrained state may have a length in the range of 4 to 6 millimeters and a length to diameter ratio in the range of 0.545 to 0.286. The pulmonary valves can be of a variety of sizes for use in respiratory tracts of different diameters, and typically have a structural framework with a maximum diameter in an unconstrained deployment state that is 5% to 30% (e.g., about 20%) greater than the diameter of the target respiratory tract. However, the disclosed implantable valve design features may be widely applicable in a variety of morphologic airways, including different diameters (e.g., 7 to 12 millimeters), lengths (e.g., 5 to 15 millimeters), and geometries (e.g., circular, elliptical, or irregular shapes), which may increase the rate of delivery and simplify the delivery process. The target respiratory tract may be measured using CT or other medical imaging techniques or by a bronchoscopy delivered measurement device. A membrane may be attached to the structural frame to effect a respiratory seal or an airflow control valve. The maximum diameter of the structural frame and the film attached thereto in the delivery state may be less than 2.7 mm (e.g., less than 2.6,2.5,2.4,2.3,2.2,2.1 mm), and is preferably about 2.3 mm. Other alternative embodiments of the lung valve may be of different sizes, allowing it to be delivered in bronchoscopes having different sized working channels. Or the lung valve may have a non-circular cross-section (e.g. oval, elliptical, irregular) in the unconstrained state, such a non-circular cross-section may also be more suitable for use in a bronchus having a non-circular cross-section. Or the valve itself may conform to a bronchus of non-circular cross-section or irregularly shaped airway wall surface.
An easy to use and convenient process is a desirable need. The lung valve may be designed to be consistently delivered to the correct location by the general physician's skill. Implantation of a lung valve can be faster than implantation of a valve in the higher respiratory tract, because implantation of only one valve is required to affect this entire lung, and the lung lobar is larger and more proximal and therefore easier to find and intervene than in the higher bronchi. In addition, evaluating the efficacy of one implanted pulmonary valve is easier and faster than evaluating multiple distally implanted valves.
One lung valve and the process of implanting it may be less expensive than implanting a plurality of advanced valves, and in particular the process of implanting only one device and implanting it may be faster.
Design considerations may also relate to particular challenges presented by placement in a lobar bronchus. For example, the length of the lobar bronchi is relatively short, the ratio of length to diameter is quite small, the cross-section of the lobar bronchi is radially asymmetric (e.g., elliptical or irregularly shaped) and the diameter of its lumen is non-uniform in the length direction (e.g., flared at the proximal end, or at the distal end, or both). Further, each of the patient's lobar bronchi has unique features, such as progressive angles and geometries.
The lung valve may comprise a structural frame that is deployable from a collapsed delivery state to a deployed configuration, a sealing element, a one-way valve, and a fixation element. These constituent elements may be mixed and collocated, and the embodiments are not limited to only the combination of the elements shown in the drawings.
Structural framework:
The pulmonary valve 241 includes a deployable structural frame 242 that may be made of a laser cut round tube, such as a biocompatible metal, such as superelastic nitinol (e.g., a tube having an outer diameter of 0.083 inches, an inner diameter of 0.072 inches, an outer diameter in the range of 0.07 to 0.085 inches, and a tube wall thickness in the range of 0.005 to 0.015 inches). A structural frame 242 may include a series of interconnected support struts that provide flexibility to the frame from a collapsed delivery state to an extended deployment state and support for the sealing membrane, valve and fixation elements. In its convergent delivery state, the diameter of such a structural frame is about the diameter of the laser cut tube used to make the structural frame. A structural framework of nitinol may be laser cut from a tube material and shaped in its unconstrained, expanded state. Another method of manufacture may include a structural framework made of shaped nitinol wires. The frame of shaped nitinol or other shape memory material is capable of undergoing elastic deformation in the direction of its unconstrained deployed state when subjected to external forces within the targeted airway, particularly those having a diameter less than the diameter of the frame after full deployment. For example, the frame in the fully deployed state may have a diameter that is 5% to 80% (e.g., about 10% belt 30%) greater than the diameter of the target airway. This elastic property also allows the device to be collapsed into a delivery configuration when loaded and contained within a delivery cannula and deployed into a deployed configuration when advanced out of the delivery cannula. The tube may contain a proximal end and a distal end, wherein said proximal end may contain a coupling element to mate with a delivery device and may have a recess such that the gripping element may transmit rotational and translational forces from the delivery tool to the structural frame. The coupling element may be considered a graspable projection arrangement that may be grasped with a bronchoscopy tool to manipulate the device during implantation, adjustment or removal of the device.
In one concept, the maximum diameter of the lung valve in an unconstrained deployment state is 12 millimeters (0.472 inches), and is suitable for placement in the respiratory tract ranging from 6 to 10 millimeters (0.236 to 0.394 inches) in diameter and can provide an effective airtight effect, while a larger sized valve, having a maximum diameter of 14 millimeters (0.551 inches), is suitable for placement in the respiratory tract ranging from 7 to 12 millimeters (0.276 to 0.472 inches) in diameter and provides an effective airtight effect. Further, after placement, the structural frame may expand and contract with movement of the bronchi (e.g., upon elastic recoil). The shape of such a structural frame, or the application of its fixation elements, may resist tilting or may function properly when placed at an angle to the bronchial central axis. In addition, the structural frame may be compressed after it is fully deployed to facilitate repositioning. For example, a delivery tool may be used to grasp or couple to the coupling element of the frame and draw it into the delivery cannula to compress the structural frame.
In the collapsed delivery state of the device, such as shown in fig. 7B, a structural frame 509, including its interconnected support strips 510, spokes 501, valve cover 505 and coupling elements 502, is flexible enough to pass through its lumen 194 as an endoscope 196 (e.g., bronchoscope) is flexed through a tortuous airway (e.g., bend radius as small as 15 mm).
Alternatively or in addition, the structural frame may be made of a bioabsorbable material, such as a laser cut high polymer (e.g., PLA, PLAGA, PDLLA) tubing.
Alternatively or in addition, the structural frame may be an expandable balloon, or made of a plastically deformable material, such as plastic, cobalt chrome, martensitic nitinol, stainless steel, silicone or polyurethane.
Optionally or alternatively, the structural framework may be impregnated with an antifungal, antibacterial, antimitotic, or anti-inflammatory agent to improve the patient's response to the implanted device.
Alternatively, the coupling elements may be laser cut on the same tubing from which the structural frame is made, or attached (e.g., welded, stranded) to the structural frame. The delivery/removal tool may be a specially designed device to mate with the valve and apply rotational and translational forces to the valve. Or the delivery/removal tool may be a conventional tweezer catheter suitable for use in a bronchoscope working tube.
In some embodiments of a lung valve, such as shown in fig. 2, 3A, 3B, 4A, 4B, 4C, and 5A, the structural frame may include interconnected support struts to form an expandable wall contact region 248, 309, 454, where the wall contact region is connected at a proximal end to spokes 247, 307, 356 that are connected to a valve cover and coupling element 245, 304, 356.
In these embodiments, such wall contact areas may conform to lobar bronchi of oval or irregularly shaped cross-section; the device can conform to the irregular surface of the respiratory tract and can play a role in sealing on the surface with protrusions, folds, grooves or other uneven surfaces; the overall length of the device may be a length suitable for placement into the lobar bronchi; the valve can be easily expectorated from the body after it is detached from the implantation site; the device may also be suitable for implantation in the lobar bronchi of a wider range of sizes and shapes.
Wall contact area
As in the example shown in fig. 3A, an implantable valve 300 is in its unconstrained, deployed state, comprising a wall contact region 309 toward a distal portion 303 of the device 300, the device being comprised of a structural frame 302 and a sealing membrane 312 attached thereto. The wall contact area resembles a cylinder, can be pressure-fixed to the inner wall of the target airway (e.g., lobar bronchi), restricts or impedes airflow between the wall contact area and the airway wall, and can contain a one-way valve 313 within the lumen of the airway, thereby greatly restricting airflow through the airway all the way through the valve. The wall contact region 309 may create an outward contact force and friction with the airway to help resist longitudinal displacement within the airway so that it may reside at the implantation site. The wall contact region 309 may be flexible or elastic to conform to the lung cylindrical morphology (e.g., irregular shape, oval shape, tapered shape, flared shape) or non-compliant (protruding, wrinkled, wavy) airway, or may exert a greater contact force to deform the airway wall, or by a combination of the two, to form a continuous annular seal band to prevent air leakage into the target region of the lung under normal intra-pulmonary pressure differential. When the device is implanted in a section of the target airway, the structural frame can exert a contact force outwards, and the contact force can expand the airway wall by not more than 20%, so that the contact can be strong enough, an ideal airtight effect can be achieved, and meanwhile, damage to tissues can be avoided, and redundant granulation tissues can be generated. The wall contact area may include circumferentially extending support strips 308 that can press the membrane 312 against the airway wall, preventing the membrane from creating an air path that can leak air due to longitudinal folds. For example, the interconnecting support struts 308 may apply contact pressure (including zig-zag, diagonal, spiral, or diamond-shaped) circumferentially continuously to the airway wall. The interconnected support strips may cooperate with the sealing membrane to apply contact pressure and may provide a contact surface between the wall contact area and the airway wall. In some cases, the sealing membrane may form folds or folds during implantation of the valve in the respiratory tract, such as for example, as a result of irregular shapes of the respiratory tract. The circumferentially continuous arrangement of the interconnecting support strips prevents wrinkling or folding of the film, thereby assisting in the airtight effect.
Or a wall contact area 309 may be barrel-shaped (e.g., slightly wider in the middle than the proximal and distal portions) or flared (e.g., greater in the distal portion than the proximal portion) in its unconstrained state, which may aid in forming a good contact area and seal with the airway wall.
The wall contact areas 309 of the structural frame 302 may provide a support for the membrane 312, which is attached to the interconnecting support bars 308, for example, by dip coating, adhesive or other bonding methods. The structural framework may be folded into a converging delivery configuration in an orderly fashion without damaging the film.
Spoke for bicycle
As still in the example shown in fig. 3A, a wall contact area 309 may be connected by spokes 307 to a coupling element 304 located at the proximal end 305 of the device 300. As shown, in the deployed configuration, the spokes 307 may radially expand from the small diameter coupling element 304 to the large diameter wall contact region 309. In its compressed delivery configuration, the spokes 307 can conduct forces (e.g., axial push-pull forces or rotational forces) exerted on the coupling element 304, such as forces directed toward the wall contact region 309 by a delivery tool coupled to the coupling element. The spokes may conduct an elastic force radially outwardly to the wall contact area but may not exert a force sufficient to affect the air-sealing function of the wall contact area. When the device 300 is in its deployed state and the delivery cannula is advanced beyond the coupling element 304, the force exerted by the delivery cannula on the spokes 307 can cause the spokes to radially contract and can compress the wall contact region 309 so that the device can be fully received within the delivery cannula or at least can reduce the diameter of the wall contact region to some extent. This removes contact forces with the airway wall to assist in repositioning the device. Alternatively, the spoke 307 may include a proximal transition portion 314, which may be pre-formed in a concave configuration or configuration at a smaller angle to the coupling element than the other portions of the spoke, such that compression of the device may be assisted by advancing the delivery cannula, wherein a force is first applied to the transition portion to begin compressing the spoke. In some embodiments, as shown in fig. 4A, 4B, 4C, and 5A, the spokes 354, 457, 501 may be curved in an "S" shape such that the coupling elements 356, 458, 502 may longitudinally approximate the wall contact areas 358, 454, 503, thereby shortening the overall length 355, 459, 504 of the device in its deployed state.
Valve cover
As in the example shown in fig. 4C, an implantable endoscopic valve 480, such as a pulmonary valve, or may include a valve cover 479 to encase or frame a one-way valve 478, and may be made of a structural frame. The valve cover 479 may be positioned on the structural frame between the spokes 477 and the coupling element 476.
In another embodiment as shown in fig. 5A, 5B and 5C, a device 500 can include a valve cover 505 that can radially deform from a collapsed delivery state to an expanded state. As shown in fig. 5A, 5B and 5C, the expandable valve cover 505 is in an expanded state. Fig. 7A illustrates the device of fig. 5A attached to a delivery rod 540, wherein the coupling element 502 of the device can be coupled to the coupling element 542 of the delivery rod. A delivery cannula 541 can compress the expandable coupling element 502 into its collapsed delivery state, wherein the expandable valve housing has a diameter 544 of a certain size after compression. Fig. 7D illustrates the device 500 and delivery sheath after detachment from the delivery rod, wherein the expandable coupling element 502 and valve cover 505 may be elastically deformed into their unconstrained, deployed state with a diameter 543 (e.g., a diameter ranging from 3 to 4 millimeters) that is greater than a diameter 544 (e.g., a diameter ranging from 2 to 2.8 millimeters as shown in fig. 7A) in the collapsed state.
Coupling element
The pulmonary valve may further include a coupling element at the proximal end of the device that is coupleable with and disengageable from a coupling element on a delivery rod according to operator manipulation. The coupling element may be part of a structural frame and may be made of a laser cut tube. For example, the coupling element of the lung valve may be in a coupled state with the coupling element of the delivery rod when contained in the delivery cannula and be disengaged when the delivery cannula is withdrawn. The operator can control an operational action (e.g., twist, trigger, slide, key in), such as from a handle connected to the delivery cannula and delivery rod, and can control the relative position of the delivery rod and cannula, thereby controlling the disengagement of the coupling element. While the radial cinch maintains the longitudinal arrangement of the coupling elements in the delivery sleeve (as shown in fig. 6C), the coupling elements of the device may remain attached to the coupling elements of the delivery rod or may be coupled to each other with the coupling elements of the delivery rod in a cinched delivery state (e.g., fig. 6A) while the expandable coupling elements of the lung valve are maintained. In the connected state, the coupling element can conduct an operational action from the delivery rod to the implantable valve, including a conductive action of longitudinal distal direction, longitudinal proximal direction, and rotation about the longitudinal axis.
In some embodiments incorporating a valve cover, the coupling element may be connected to the valve cover. For example, as shown in fig. 4C, the coupling element 476 is located directly at the proximal end of the valve cover 479. The coupling element in this embodiment has a recess 475 cut from the tube structure. The proximal neck 474 of the groove is narrower than its distal flared structure 473 (as shown in fig. 4D). The overconnection 472 from the neck 474 to the distal flared structure 473 may be angled, for example, to assist in the disconnection and reconnection of the coupling element 476. The length 471 of the coupling member 476 may be in the range of about 0.11 to 0.12 inches (2.8 to 3 millimeters). The distal end of the coupling element may be a tubular portion that is uncut along its circumference and is connected to spokes 477 of the structural frame. The tubular portion may act as a valve cover 477.
In another example, as shown in fig. 5A, 7A-7D, the coupling element 502 is directly adjacent to an expandable valve cover 505. The coupling element 502 contains a number (e.g., 2 to 10, 8) of coupling ends 506 that are adapted to be placed into the negative space of the delivery rod coupling element 542 and held in a coupled position by the convergence sleeve 541. The terminal end of the coupling end 506 may be rounded to help avoid injury to the respiratory tract. Each coupling end 506 may include a neck section 507 at a distal end of its head end 508, wherein the neck section is narrower than the head end and both are sized to fit within the negative spaces of the neck section 545 and the head end 546 of the delivery rod coupling element 542 (as shown in fig. 7D). This maintains the coupling elements 542 and 502 in a locked state, and the coupling element combination can be conductively displaced from the delivery rod toward the valve when collapsed in the delivery sheath, or can be decoupled when the delivery sheath is withdrawn.
Cover/seal
The disclosed lung valves may further comprise at least one membrane (470 in fig. 4C) coupled to the structural frame for creating an air seal in the lung bronchi such that air may only or at least mostly circulate from the openings of the membrane and may direct air through the one-way valve 478. The material of the sealing membrane may further prevent ingrowth of tissue so that the valve may be safely removed after a period of implantation. The material may be a material that prevents adhesion to itself, thereby assisting in deforming the valve from the collapsed delivery configuration to the deployed deployment configuration.
Such a membrane associated with the structural frame may be made of a thin, flexible, durable, foldable, or elastomeric material, such as urethane, polyurethane, ePTFE, silicone, parylene, or a blend of materials. The film may be formed by insert molding, dip coating or spray molding, or other methods of manufacturing medical balloons or films. It may be attached to the frame, for example by coating the frame, laminating, dip coating, spray coating, hot melt, adhesive or sewing on the outside of the frame. As shown in the example of fig. 4C, the membrane 470 may cover the wall contact region 469 of the structural frame 468 and at least a portion of the lumen region 466, such that air cannot circulate within the bronchial lumen, allowing air to circulate only from the one-way valve 478, and may prevent air leakage between the wall contact region and the airway wall at its perimeter. As shown in fig. 4C, a lumen coverage area 466 may be proximal to the wall contact area 469, and the membrane 468 may optionally be contiguous with spokes 477. Alternatively, as shown in fig. 4A, a lumen coverage area 359 may be at the distal end 353 of the wall-contacting area 358. This configuration may also allow the device to seal against airflow in the event of placement in an irregularly shaped bronchus, or misalignment with the bronchus axis.
The sealing membrane may be placed over the cavity formed by the structural frame and attached to the inside surface of the structural frame as shown in fig. 5A. Or the sealing film may be attached to the outside of the structural frame. Alternatively, the sealing membrane may comprise an inner membrane attached to the inner surface of the structural frame and an outer membrane attached to the outer surface of the structural frame, wherein the inner and outer membranes may be attached to each other between support bars or spokes so as to seal a portion of the structural frame.
The airflow 181 shown in fig. 7D may flow from the lobes of the lung at the distal end of the device 500, through a valve 511, and out of the lung. The sealing membrane 512 in combination with the one-way valve 511 prevents reverse air flow into the lobes. Alternatively, the membrane may form a one-way valve, or the valve may be another separate structure attached to a structural frame or sealing membrane.
The sealing membrane portion 512 supported by the interconnecting support strips 510 on the wall contact area 503 may be flexible and may contain slack portions that promote the airtight effect by bulging outward and applying contact pressure to the airway wall as the differential pressure of air flowing through the device or device increases.
The sealing membrane and structural frame, by virtue of being the wall contact area, form a continuous contact surface along the circumference of the target airway wall.
In another embodiment of the seal, the seal may include a passageway that is specifically adapted to allow air to pass through the seal from either direction during the initial stage of implantation of the device and to close gradually to block air flow through channels other than through the valve. For example, the passageway may be located adjacent to the sealing structure surface of the airway wall and may be blocked by naturally occurring secretions within the airway over time (e.g. after a few weeks). The gradual or delayed sealing action delays the evacuation of entrapped air and the subsequent reduction of lung lobe volume so that the lobe switching action in the lungs being treated may be performed more gradually, which may reduce the incidence of adverse effects such as pneumothorax or healthy lung tissue damage.
Or the film may slow release certain chemicals over time. For example, the film may deliver a bactericidal, antibacterial or other agent to reduce the risk of infection, pneumonia, rejection or other side effects. For example, the film may be impregnated with an antifungal, antibacterial, antimitotic, or anti-inflammatory agent to improve the patient's response to the implanted device.
Valve
The device may be used to provide a seal to block airflow, or at least may be effective to block air from passing through the target airway via other channels than through the one-way valve. The sealing action may be achieved by connecting a membrane to the structural frame, and the sealing membrane may also form the one-way valve. Or the valve may be another structure that is attached to the sealing membrane or structural frame. Generally, the valve allows air to circulate in at least one direction, primarily from the diseased lobes rather than into them. In other words, as shown in fig. 7D, a lung valve 500 may restrict the airflow 181 from the distal end to the proximal end of the lung valve.
Alternatively, the valve material may be impregnated with an antifungal, antibacterial, antimitotic, or anti-inflammatory agent to improve the patient's response to the implanted device.
For example, shown in fig. 4D, which is a cross-sectional view of the device of fig. 4A, a one-way valve 478 may be made of a flexible, non-adhesive elastomeric material such as urethane, polyurethane, ePTFE, silicone, parylene, or a blend of materials. The one-way valve 478 may be a duckbill valve comprising a funnel-like structure transitioning from a distal flared end to a proximal sealed end. The distal flared end may be of a tubular configuration having an outer diameter that is connected to the lumen coverage area 466 of the sealing membrane 470 and is adapted for placement within the valve cover 479 in certain embodiments. The distal flared end may have a diameter in the range of 1 to 4 millimeters (e.g., 3 to 4 millimeters). The duckbill valve 478 includes a pair of oppositely disposed and sloped wall structures with distal ends that contact each other at a proximal sealed end to form a lip. The lip structure is joined on both sides and can be flattened. The wall structures are movable relative to each other to form an opening through which fluid flows when the lip structures are separated. When the wall structures encounter a fluid flowing in the direction indicated by arrow 181 under a cracking pressure, the wall structures separate from each other, forming an opening for the flow of fluid, as shown in fig. 7D. The lip structure may remain closed when a counter-flowing fluid is encountered and may prevent fluid flow through the duckbill valve. Or another one-way valve common in the medical device arts may be used. Or the lip structure may normally open at least slightly without a pressure differential across the valve, which may reduce or eliminate cracking pressure and reduce opening reaction time.
Fixing mechanism
The lung valve may have a fixation mechanism such as a spike, a radial squeeze structure or a radial intervention structure. The fixation mechanism may hold the device in a target position in the patient's respiratory tract. The device may be removed by applying a force to the coupling element, thereby overcoming the inherent force of the securing mechanism. Or the anchoring mechanism may be disengaged from the respiratory tract by compressing the pulmonary valve.
Fig. 2 shows a structural frame 242 comprising support bars 249 interconnected in a zig-zag fashion about wall contact areas 248. At the distal end 243 of the device, such interconnected support strips may terminate at a junction 250 which may act to exert an outward contact force against the targeted airway wall, as well as a force vector in the distal direction 243. For example, the terminal connection portion 250 may be flared. Or the end of the connection terminal 250 may be a rounded end 251 so as to increase the surface area and reduce the chance of puncturing or injuring the airway wall. The terminal connection portion 250 and/or the rounded end 251 may be secured by applying friction and outward radial forces.
The lung valve 241 includes a coupling element 245, which may be a cylindrical structure 244, including an open site for mating with a mating coupling element on a delivery rod. The cylindrical structure includes an annular ring 246 that connects the coupling element 245 with the spoke 247 and can provide structural support for the spoke.
Figures 3A to 5C illustrate other embodiments of the lung valves 300, 260, 300, 350, 450. These lung valves contain radially outward spikes 301, 261, 351, 451, 452, 467, 513, 514. As in the example of fig. 4C, the lung valve 480 comprises a structural frame 468 that includes radially-deployed prongs 467 that can be deployed therewith when the structural frame is deployed. Such a spur 467 is part of the structural frame, laser cut from the tubular structure, and pre-shaped to an expanded state. In one embodiment, the spike includes a non-sharp (e.g., square cut, rounded) tip and acts as a fixation mechanism by wedging into a groove or uneven surface in the airway wall, such as a groove formed by cricoid or cartilaginous plates, or simply concentrates frictional forces on the airway wall. In addition to radial expansion, the spurs may be biased toward the proximal end (as shown in fig. 4A and 4C) or the distal end (as shown in fig. 3A and 3B), or the device may contain spurs toward both the proximal and distal ends (as shown in fig. 4B and 5A) to provide a force vector against the airway wall to further prevent longitudinal displacement within the airway. Fig. 4B shows a lung valve embodiment comprising radially expanding barbs 451, the barbs 452 that cross toward the distal and proximal portions being integrated on a structural frame 453.
The lances 451, 452 may be positioned at a wall contact area 454 of a lung valve 450, may be at the proximal portion, the distal portion, or somewhere in between, but may preferably be at the distal portion, as the distal portion will first contact the airway wall when deployed from the delivery state.
In the collapsed delivery state, the prongs 451,452 may be retracted and flush with the spokes 457 and the interconnecting support strips 460 so that the device may be advanced within the delivery cannula.
The spurs 451,452 may protrude from the wall contact region 454 by a distance in the range of 0.25 to 1 millimeter.
Regardless of the fixation mechanism embodiments, the pulmonary valve 450 may be implanted and a test pulling force may be applied to the device to ensure that the device is secured in its place prior to removal of the delivery tool and bronchoscope. When the delivery tool is coupled to the grasping mechanism of the implanted pulmonary valve, the pulling force may be generated by applying a slight pulling force to the delivery tool. A force gauge may be used to indicate the force applied to the lung valve. If the valve falls below a predetermined force, the fixation mechanism of the stent is not suitable for the current implantation situation, requiring another size device, or requiring repositioning of the device.
Examples example
Fig. 3A shows an example of a lung valve comprising a structural frame 302, the wall contact area 309 of which comprises interconnected struts 308 forming a diamond pattern. The structural frame 302 includes a coupling element 304 at its proximal portion 305 that is connected to a proximal ring structure 306. Support spokes 307 are connected to the ring structure 306 and extend radially outwardly therefrom. In the wall contact area 309 with the airway wall, each support spoke diverges 308, gathering at the distal end at the junction 310 and connecting with the adjacent branches at the grating junction 311. The structure is interconnected in a diamond-shaped mesh 312 at connection points 311 and connected to the support spokes 307 at the proximal end and the connection points 310 at the distal end are free ends. The structural frame 302 includes a spike 301 angled radially outwardly and distally to be deployed when the frame is deployed. A sealing membrane 316 is attached to the wall contact region 309 around the structural frame and extends inwardly to block the lumen coverage region 315 at the distal end of the device and is attached thereto to a valve 313 contained in the wall contact region 309. This design may provide support for the sealing membrane 316 and may provide a seal between the device and the airway wall, while also allowing the sealing membrane between the interconnecting support strips to bulge outwardly during inspiration (e.g., when the pressure of the gas at the proximal end 305 of the device is higher than at the distal end 303), providing additional sealing. The diamond-shaped mesh 312 and mesh attachment points 311 also enhance the sealing effect between the device and the airway by preventing folds from occurring in the membrane.
Fig. 3B shows a lung valve 260 similar to the device 300 shown in fig. 3A, but with the sealing membrane at the distal end 263 of the lung valve 260 covering both the proximal coverage area 275 covered by the membrane with spokes 267 and the distal cylindrical structural area 269 covered by the membrane with support strips 268. The sealing membrane may form an air barrier in that it includes both a proximal coverage area 275 that effectively blocks the airway and a distal cylindrical structural area 269 that forms a deployable wall-contacting area 269 that creates a seal with the airway wall. The membrane 276 may continue to form a one-way valve 273, which may be located within and supported by a valve cover 266. The cylindrical valve cover 266 may also form a coupling element 264.
In the lung valve 260, the one-way valve 273 and the membrane 276 may be a complete element, such as a plastic layered structure.
In the lung valve 260, the spokes 267 can include spikes 261 that extend outwardly from the spokes and the expandable wall contact area 269. The structural frame is a net structure formed by proximal support bar 268 and distal support bar 262 at joint 271. The support bar 262 may be rounded or curved at its distal end 270 and may support the distal circumferential edge of the sealing membrane.
Fig. 4A shows another lung valve 350 comprising a structural frame 352 open at a distal end 353. The lung valve 350 is similar to the lung valve 300 shown in fig. 3A, but in the deployed state the frame 352 comprises spokes 354 which radially spread out to form an "S" shaped curve as shown, such that the coupling element 356 is closer to the centre of the device than the device shown in fig. 3A, thereby reducing the overall length 355 of the device. The reduced overall length allows the device to be more suitable for use with shorter lobar bronchi and to be easily expectorated when the device is detached. Such curved support bar spokes 354 may provide more force to the airway wall than the device shown in figure 3A. Or the structural frame may contain the spurs 351 formed by the support spokes 354 (e.g., laser cut). As shown, the spurs 351 are angled outwardly and proximally. Alternatively, as shown in fig. 4B, the prongs 452 and 451 extend radially outward from the wall contact area 454 and alternate in a different direction. The spike 451 is oriented toward the distal end 455 and the spike 452 is oriented toward the proximal end 456. The alternating spurs may allow the device 450 to be secured in a segment of the lobar bronchi and may prevent inward and outward displacement in the respiratory tract, and may further maintain a certain orientation.
The sealing membrane on the lung valve 350 may comprise a length of cylindrical structure 361 attached to the inner surface of the support band and a one-way valve 360. The sealing membrane may thus form a barrier extending radially inward from the support band 352 to the one-way valve.
Fig. 4C shows another lung valve 480 similar to the device shown in fig. 4A, but with valve 478 therein at the proximal end and supported in a valve cover 479. The membrane 470 is connected to support struts interconnecting at wall contact areas 469 and spokes 477 at lumen coverage area 466 and forms the one-way valve 478. Fig. 4D is a longitudinal cross-sectional view of the device shown in fig. 4C.
Fig. 5A shows another embodiment 500 of a lung valve, wherein the valve cover 505 is expandable. The valve cover is formed on interconnected support struts that are deformable from a collapsed delivery state to a deployed deployment state upon release from the delivery sheath. The one-way valve 511 supported by the valve cover may be made of a flexible film (e.g., an elastic material) that is adapted to the delivery configuration of the valve cover after compression (e.g., folding) and expands as the valve cover expands. The coupling element 502 may also be extended. As shown, the spoke 501 is "S" shaped, but may be a straight spoke 307 as shown in fig. 3A. The spikes 513,514 are shown in alternating orientations and are distributed in the middle of the wall contact area 503, but may be other types of spikes as disclosed herein.
Delivery tool
As shown in fig. 6A and 6B, a delivery tool 195 for delivering a pulmonary valve (e.g., 480) through a bronchoscope 196 may comprise a delivery rod 197 that may be a flexible, extendable, tubular, or rod-like structure and that includes a pre-shaped coupling element 199 at its distal end for inter-coupling with a coupling element (e.g., 476) of the valve and that includes a delivery cannula 211 and handle 198 at its proximal end. For example, the coupling element 199 can be a cut, groove, or a negative space that can mate with the positive space on the valve coupling element 476. For example, to interact with coupling element 476 comprising a scored neck structure 474, scored flared structure 473, and transitional sloping structure 472, the coupling element 199 may comprise a flared structure 200, neck structure 201, and transitional sloping structure 202 between the neck structure 201 and flared structure 200. A delivery rod may be flexible and may be passed longitudinally through a curved bronchoscope within a curved airway without being stretched, compressed, or wrinkled so that it may transmit motion from a proximal end (e.g., a handle) to coupling element 199 and to a pulmonary valve. A delivery rod may be made of a polymer and may contain an embedded laser cut tube or a compact coil.
In another embodiment, as shown in fig. 6D, a delivery rod 205 may comprise a central lumen 203 that may be used for delivery through a guidewire 204 or for delivery through or other devices, such as an endoscope. Alternatively, as shown in fig. 6E, a delivery rod 208 may include a distally extending hub 209 that may be used to hold a valve (e.g., 87) in the delivery rod 208, to increase coupling force, to orient the coupling element 264 of the valve when it is retrieved, or to adjust its position.
Or the delivery tool may comprise a delivery cannula 211 that incorporates the several delivery rods 197, 205, and 208. As shown in fig. 6B, the sleeve may control the mating coupling element 476 and coupling element 199 received within the sleeve in a locked state. Such a mating element combination may be released upon retrieval of the cannula, or forward delivery of the mating coupling element 476 and coupling element 199 out of the cannula. Such angled transition structures 202 and 472 may assist in the release or reattachment of the mating element combination. The sleeve may be used to constrain the valve in a delivery state, as shown in fig. 6B, when the valve is being delivered in the working channel. The distal portion of the delivery cannula (e.g., about 10 cm from the distal tip) may be relatively more flexible, allowing it to bend or shuttle in a bronchoscope where distal bending may travel in the tortuous respiratory tract. The delivery cannula does not deform in compression or tension over the entire length. The delivery sleeve is circumferentially non-deformable at least at its distal end so that it may contain a lung valve and be compressed into a collapsed delivery state. A laser cut steel tube may be embedded in a polymeric material, such as Pebax nylon elastomer material, at its distal end portion to provide hoop stress and resistance to circumferential deformation. The delivery cannula may be made of a polymeric material, such as Pebax nylon elastomer material or polyimide, woven or wound with a metallic coil to resist compression, tension or wrinkling. The outer diameter of the delivery cannula 211 may be sized to slide in shuttle within the working channel 194 of the bronchoscope (e.g., a cannula having an outer diameter in the range of 2 to 2.7 millimeters may fit 2.8 millimeters). The inner diameter of the sleeve may be in the range of 1.5 to 2.5 mm.
Or a delivery tool may comprise a pincer-type tool 214 that can be slid through the lumen 217 of the delivery cannula 216 and which can grasp tissue, such as a respiratory tract protuberance 62, through the opening of a one-way valve on a pulmonary valve, as shown in fig. 6F. The pincer-type tool may contain a pincer structure 215 at its distal end, which may be controlled by a trigger mechanism (not shown) on the handle at the proximal end of the pincer-type tool. During implantation, the pincer structure 215 may be advanced through the lumen 217 of the delivery sheath and the valve, for example, in a contracted delivery state with the valve within the delivery sheath 218, and the pincer structure may be triggered to grasp tissue, for example, the respiratory tract carina proximal to the distal end of the lobar bronchi. A flexible rod 220 coupled to the tweezer structure 215 may be used as a rail to assist in delivering a valve. Fig. 6F omits the membrane and valve for the purpose of illustrating such a structural frame, but it should be understood that the lung valve would include a sealing membrane and valve as illustrated in other embodiments. The delivery rod 216 may be advanced relative to the delivery sheath 218 to push the valve out of the sheath to assume a deployed configuration. This action may be accomplished by withdrawing the cannula with respect to the pincer-type tool and lung tissue, or advancing the delivery rod while maintaining the relative position of the cannula and the pincer structure, or a combination of these. Or the delivery rod may be interlocked with the pincer-type tool at the proximal end of the delivery tool, for example by a collet or set screw, to ensure the translational position of the valve relative to the pincer-type tool and thus the pulmonary bronchi when the pincer structure grasps pulmonary tissue. Thereafter, the cannula may be withdrawn (as shown in fig. 6A) either through a trigger mechanism 212 on the delivery tool.
In another delivery tool embodiment, the coupling element 542 of the delivery tool, as shown in fig. 7A, may be mated with the coupling element of the expandable lung valve (e.g., 502 on device 500).
Or the delivery tool may include a handle 198 in the proximal region having a detent (e.g., thumb push) that controls the sliding translational movement of the rod 197 relative to the sleeve 211 to facilitate one-handed operation when delivering or retrieving the valve from the sleeve. For example, a sleeve 211 may be coupled to the handle body and a rod 197 may be slidably engaged in the sleeve and coupled to a movable (e.g., rotational or translational) transmission in the handle and may be moved by a mating transmission coupled to a brake, such as a thumb push, slider or turn knob. The handle may contain one or more triggers, may move the delivery rod, and may control the position of the lung valve from a fully contained position as shown in fig. 7B, to a partially deployed position when the coupling elements are connected as shown in fig. 7C, to a fully deployed and detached position as shown in fig. 7D. For example, a delivery tool 195 and lung valve 500 may be placed within the sterile package in a first position (state 1) with the delivery rod 540, the coupling element 542,502 remaining interlocked, and the device 500 deployed as a portion, as shown in fig. 7A. The first trigger may be used to deliver and retrieve the device, partially deploying it out. By this step, the position and fitness within the target airway is assessed as it is being viewed through the lens 193 of the bronchoscope 196. The first trigger may be such that control is stopped at the state 1 position before the device is completely disengaged. A second trigger, such as a trigger, may be used to fully retract the delivery cannula or unlock the first trigger from state 1 for further delivery and disengage the device 500 (fig. 7D). The first trigger and the second trigger may be ergonomically arranged on the handle 198 for single hand operation, e.g., the first trigger may be located in the thumb-operated region and the second trigger may be located in the index finger-operated region of the same hand. Or the delivery cannula and delivery rod may be coupled to a rotary trigger on the handle that is rotated while maintaining the handle in a comfortable position with the operator's hand.
Suit
Or the valve may be preloaded in its collapsed delivery state in a (or disposable) delivery sheath and coupled to the delivery rod shown in fig. 6B. Or a lung valve may be coupled to the delivery rod within the delivery cannula, but the remainder of the lung valve is in an unconstrained state outside the delivery cannula, as shown in fig. 7A. The assembled structure may be stored in a sterile package with instructions for use. The lung valve in its partially deployed state may assist in monitoring and avoid deformation of the material due to prolonged constraints.
Delivery of
A method may include the following delivery steps:
Determining the position of the implanted valve according to CT scanning measurement, and the size and length of a target respiratory tract;
macroscopic examination of a lung valve coupled in a delivery system (as in fig. 7A);
Delivering a bronchoscope to the target lobar bronchi through the patient's endotracheal tube;
retracting the pulmonary valve into the delivery cannula and delivering the preloaded pulmonary valve delivery system forward through the working channel of the bronchoscope;
Pushing the distal end of the delivery system out of the distal end of the working channel to the desired valve location of the target respiratory tract (fig. 7B);
While maintaining the relative position of the bronchoscope and the respiratory tract, withdrawing the delivery cannula from the proximal end relative to the pulmonary valve, leaving the valve in a deployed but still coupled state (state 1, fig. 7C);
the position, and the appropriateness, alignment orientation and sealing effect are monitored by the lens of the bronchoscope. Confirming the mechanical fixing and matching effect of the valve and the respiratory tract wall through a light-pull delivery system;
Indicating that the lung valve has blocked the airway by confirming cessation of respiratory motion within the airway;
if the position, and the moderate degree, the arrangement orientation, the sealing effect and the fixing effect are not ideal, the delivery system can be pushed and pulled to adjust;
If the position, and the proper, alignment orientation, sealing effect, and securing effect remain undesirable, the lung valve may be retracted within the delivery sheath;
repositioning the delivery sleeve and the pulmonary valve;
If the desired results of position, and proper, alignment orientation, sealing effect, and securing effect are achieved, retracting the delivery sleeve to the position of State 2, thereby completely paying out the pulmonary valve and disengaging the coupling element of the valve from the coupling element of the delivery system;
removing the delivery system;
detecting the pulmonary valve through a lens of the bronchoscope;
The bronchoscope is removed.
Although at least one exemplary embodiment of the invention has been disclosed herein, it should be understood that any modifications, substitutions and alternatives to those of skill in the art will be apparent and can be made without departing from the scope of the invention. This disclosure is intended to cover any adaptations or variations of the exemplary embodiments. In addition, in the present invention, the term "comprising" does not exclude other elements or steps, the term "a/one" does not exclude a plurality, and the term "or" means either or both. Furthermore, unless the invention or context indicates otherwise, features or steps of the invention that have been described may also be combined with other features or steps and used in any order. The entire disclosure of a patent or application claiming priority hereto is incorporated herein by reference.