DEVICES FOR THE TREATMENT OF PULMONARY DISORDERS WITH IMPLANTABLE VALVES
20220211481 · 2022-07-07
Inventors
- Sean TOTTEN (Kirkland, WA, US)
- Jason Lee (Milpitas, CA, US)
- Joe M. GUERRICABEITIA (Shoreline, WA, US)
- Don TANAKA (Saratoga, CA, US)
Cpc classification
A61B17/12177
HUMAN NECESSITIES
A61F2/2476
HUMAN NECESSITIES
A61B17/12172
HUMAN NECESSITIES
A61B2017/00853
HUMAN NECESSITIES
A61F2220/0016
HUMAN NECESSITIES
A61F2/04
HUMAN NECESSITIES
International classification
A61F2/04
HUMAN NECESSITIES
A61F2/24
HUMAN NECESSITIES
Abstract
A flow control device for a lobar bronchial passageway including: a one-way valve; a braided wire structural frame, wherein the structural frame is expandable from a collapsed configuration to an expanded configuration; and a sealing membrane mounted to at least a distal portion of the structural frame, wherein the sealing membrane forms an enclosed wall defining at least a portion of an airflow passage through the flow control device, and the one-way valve is included in the airflow passage.
Claims
1. A flow control device for a lung of a living patient, the flow control device comprising a support frame, while in an expanded configuration, including: an outer cylindrical section with a distal circumferential edge, wherein the outer cylindrical section is sized and configured to contact a lobar bronchus in a lung of a patient; an inner cylindrical section with a distal circumferential edge, and an annular section spanning and connecting proximal ends of the outer and inner cylindrical sections, a sealing membrane covering and/or attached to the distal circumferential edge of the outer cylindrical section and configured to span a cross sectional area of the lobar bronchus, and a one-way valve attached to or integrated with the sealing membrane, wherein the one-way valve includes an inlet configured to be oriented towards a downstream flow region of the lobar bronchus, wherein a flow direction is of air inhaled into the lung and flowing through the lobar bronchus, and an outlet configured to be oriented towards an upstream flow region of the lobar bronchus, and wherein the one-way valve extends into the inner cylindrical section.
2. The flow control device of claim 1 wherein the sealing membrane covers at least a portion of an outer surface of the outer cylindrical section.
3. A flow control device for a bronchial passageway comprising: a proximal end, a distal end, a central axis; a structural frame, wherein the structural frame is transitionable between a compressed configuration and an unconstrained expanded configuration; a sealing membrane connected to the structural frame; and a one-way valve, wherein the structural frame comprises at least one of a wire braid, mesh or woven material arranged in a tubular shape.
4-5. (canceled)
6. The flow control device of claim 3, wherein at least one wire forming the wire braid, mesh or woven material has a diameter in a range of 0.003″ to 0.008″.
7. (canceled)
8. The flow control device of claim 3, wherein the wire structural frame comprises a braid angle in a range of 35° to 55° in the unconstrained expanded configuration.
9.-15. (canceled)
16. The flow control device of claim 3, wherein the at least one wire of the structural frame forms closed loop ends at the distal end of the flow control device.
17. The flow control device of claim 16, wherein the closed loop ends have a smaller angle than a braid angle of the at least one wire.
18. (canceled)
19. The flow control device of claim 17, wherein the closed loop ends comprise short and long closed loop ends arranged in an alternating pattern.
20.-22. (canceled)
23. The flow control device of claim 16, wherein the at least one wire comprises wires braided or woven into the wire structural frame forming closed loop ends on the distal end.
24. The flow control device of claim 16, wherein the at least one wires has terminals that are gathered to form spokes at the proximal end of the support structure.
25.-28. (canceled)
29. The flow control device of claim 3, further comprising spokes and a coupler, wherein the spokes connect the coupler to the structural frame.
30. The flow control device of claim 29, wherein the spokes extend from the coupler at an angle to a central axis of the wire support structure in a range of 0° to 40° in the expanded configuration.
31.-32. (canceled)
33. The flow control device of claim 29, wherein the spokes comprise an S-shaped curve.
34. The flow control device of claim 29, wherein the spokes are longer than the radius of the flow control device in its unconstrained expanded configuration.
35. The flow control device of claim 29, wherein the spokes are inverted into a lumen of the structural frame when in the unconstrained expanded state.
36. The flow control device of claim 29, wherein the spokes are invertible into a lumen of the structural frame when in the unconstrained expanded state.
37.-42. (canceled)
43. The flow control device of claim 3, wherein the sealing membrane is configured to direct a majority of bronchial passageway airflow through the one-way valve.
44. (canceled)
45. The flow control device of claim 3, wherein the sealing membrane comprises an airway wall contact region, and a luminal covering region.
46.-48. (canceled)
49. The flow control device of claim 3, wherein the sealing membrane occludes a part of an opening of the structural frame while the one-way valve is closed.
50.-52. (canceled)
53. The flow control device of claim 49, wherein a portion of the sealing membrane that occludes the opening has an area larger than the cross section of the opening.
54. (canceled)
55. The flow control device of claim 3, wherein the sealing membrane comprises a hydrophilic micropatterned surface.
56. The flow control device of claim 55, wherein the hydrophilic micropatterned surface is on an external surface of the sealing membrane where the sealing membrane is connected to a contact area of the support structure configured to contact the bronchial passageway.
57. (canceled)
58. The flow control device of claim 55, wherein the micropatterned surface is on at least one of an internal surface of the sealing membrane or the one-way valve.
59. The flow control device of claim 55, wherein the hydrophilic micropatterned surface comprises nanostructures molded on to the sealing membrane.
60.-66. (canceled)
67. The flow control device of claim 3, wherein the one-way valve and the sealing membrane are a single-piece component.
68. The flow control device of claim 3, wherein the one-way valve is a duckbill or Heimlich valve arranged on to allow air to flow predominantly from the distal end to proximal end.
69. The flow control device of claim 3, wherein the one-way valve is connected to a luminal covering region of the sealing membrane.
70. The flow control device of claim 3, wherein the one-way valve comprises a distal flared end having a diameter in a range of 1 mm to 4 mm.
71. The flow control device of claim 3, wherein the one-way valve comprises a length in a range of 3 mm to 8 mm.
72. The flow control device of claim 3, wherein the one-way valve comprises lips that are normally open when there is no pressure differential across the on-way valve.
73.-133. (canceled)
134. An assembly of an air flow control device and an insertion tool for a bronchial passageway comprising: an air flow control device, wherein each of the air flow control devices includes: a one-way valve; a structural frame, wherein the structural frame is expandable from a collapsed configuration to an expanded configuration; a sealing membrane mounted to at least a distal portion of the structural frame, wherein the sealing membrane forms an enclosed wall defining at least a portion of an airflow passage through the flow control device, and the one-way valve is included in the airflow passage, and a first coupler at a proximal end of the airflow control device; a delivery sheath configured to be positioned in a bronchial passageway, wherein the delivery sheath includes a distal end, wherein the air flow control device, while in the collapsed configuration, is within the delivery sheath; a delivery shaft within the delivery sheath and extends through the delivery sheath towards the distal end; and a second coupler at the distal end of the delivery shaft, wherein the second coupler is configured to securely engage the first coupler, wherein the delivery shaft is configured to advance through the delivery sheath to push the air flow control device from the distal end of the delivery sheath and into the bronchial passageway, wherein the air flow control device is configured to expand from the collapsed configuration into the expanded configuration after the air flow control device is pushed out of the delivery sheath, and wherein the air flow control device is configured to automatically release from the second coupler when an actuator on a handle of the assembly is actuated.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0195] The disclosure herein is related to systems, devices, and methods for modifying air flow to and from a targeted portion of a patient's lung, which may be substantially diseased, with an implantable device in order to reduce the volume of trapped air in the targeted portion of lung, thereby increasing the elastic recoil of the remaining lung volume.
[0196] The authors conceived of and disclose herein, implantable lung volume reducing devices and medical techniques for implanting lung volume reduction devices through the trachea and bronchi, using minimally invasive deployment, bronchoscopic and surgical techniques. The device may be embodied as an endobronchial valve, such as a one-way lobar valve.
[0197] Also disclosed is a novel treatment for patients suffering from hyper-inflated lung (e.g., emphysema, COPD, bronchitis, asthma) comprising the application of a minimally invasive bronchoscopy technique to implant a lung volume reduction device into a lung airway of a patient. The implantable lung volume reduction devices, which may be generally referred to as “lobar valves” disclosed herein are intended to be placed in an airway trunk of a lobe such that a single valve regulates air flow to or from the complete lobe, which may have benefits over previously attempted valves that were intended for multiple valve placement in higher generation airways. Benefits of a lobar valve may include lower cost, faster procedure, easier implantation, easier removal, and stronger retention. However, some features of devices disclosed herein may be novel and useful for use in higher generation airways and are not limited to devices configured for placement in a trunk of a lobe.
[0198] Anatomy and Design Inputs and Challenges:
[0199]
[0200] Lobar valves may be implanted in a secondary bronchus, also known as a lobar bronchus. Humans have one lobar bronchus providing air passage to each lobe of the lung, including three in the right lung and two in the left lung. The right-side lobar bronchi include the right upper lobar bronchus 44, right middle lobar bronchus (not shown for simplicity), and right lower lobar bronchus 46. The left side lobar bronchi include the left upper lobar bronchus 50 and left lower lobar bronchus 52. Overlapping cartilage plates of the lobar bronchi provide structural strength to maintain patency of these bronchi. Humans may typically have lobar bronchi having an average circumference in a range of 19 mm to 56 mm. The average length is about 19 mm (e.g., in a range of about 3 to 41 mm).
[0201] Lobar valves disclosed herein are transitionable from a contracted delivery state to an expanded deployed state. In the contracted delivery state the lobar valve is compressed and constrained in a delivery sheath that can be advanced through a bronchoscope working channel. When advanced out of the delivery sheath the lobar valve transitions to its expanded state, for example via elastic properties of a structural frame. The circumference of the lobar valve in its expanded state may be larger than the circumference of the targeted airway where it is implanted, so that a radial force is applied by the lobar valve to the airway wall.
[0202]
[0203] A lobar valve may assume its contracted delivery state when delivered through a working channel of a bronchoscope, optionally contained in a delivery sheath and manipulated with a delivery tool. The lobar valve and optional delivery sheath and delivery tool may be sized to pass freely through a working channel of a bronchoscope. For example, a lobar valve adapted to be delivered with a delivery tool through a working channel with a 2.8 mm lumen may have a maximum diameter of 2.6 mm (e.g., a maximum diameter of 2.5, 2.4, 2.3, 2.2. 2.1 mm). In some embodiments lobar valves may comprise a structural frame having a delivery state and deployed state, wherein the delivery state has a maximum diameter in a range of 2 (0.0787″) to 2.5 mm (0.0984″), preferably 2.11 mm (0.083″).
[0204] Ease of use and procedural expediency is a desired requirement. The lobar valve may be designed to be consistently delivered to a correct location with average physician skill. Compared to valves that are implanted at higher generation airways implanting a lobar valve may be a faster procedure because only one valve needs to be implanted to affect an entire lobe, the lobar bronchi are larger, more proximal and hence easier to access and find than distal higher generation bronchi. Also, assessing the function of a single implanted lobar valve is faster and easier compared to assessing multiple distally implanted valves.
[0205] A lobar valve and procedure for implanting one may cost less compared to implanting multiple higher generation valves in particular since there is only one device to implant and the procedure is faster.
Design considerations may also consider particular challenges for placement in a lobar bronchus. For example, the length of a lobar bronchi is relatively short, the length to diameter ratio is considerably smaller, the cross section of a lobar bronchus is radially asymmetrical (e.g., ovular or irregular), and the diameter of the lumen is inconsistent along the length of the lobar bronchus (e.g., flared at the proximal, distal or both ends). Potentially, a single lobar valve placed in a lobar bronchus may experience a greater air pressure difference between its proximal and distal sides compared to a plurality of valves positioned in several higher generation bronchi of a lobe. Furthermore, each particular lobar bronchus in a patient has unique characteristics such as the angle of approach and geometry.
[0206] Structural Frames:
[0207] The structural frame provides a framework to hold the membrane and valve in a desired orientation and position in a target bronchus. The structural frame applies an outward radial force to press the membrane against the airway wall and hold the one-way valve in the airway so air is directed through the one-way valve.
[0208] The structural frame 101 may be made by braiding wires into at least a generally cylindrical shape. The generally cylindrical shape of the structural frame can constitute an airway wall contact region 110 that is intended to expand to contact the airway wall and to flexibly conform to the surface of the airway wall. The wires may be elastically or superelastically flexible with shape memory ability, for example the wires may be made from Nitinol that is superelastic above a temperature of body temperature (about 37° C.) or lower. As the braided wire structural frame transitions from the compressed delivery state to deployed state the device diameter (excluding optional radially extending barbs) increases from a first device diameter 111′ (
[0209] The wires used to form the structural frame braid may be for example superelastic Nitinol wires having wire diameter in a range of 0.003″ to 0.008″ (preferably in a range of 0.005″ to 0.006″). The structural frame 101 may have a braid angle 117 in a range of 35° to 55° in its unconstrained expanded configuration (see
[0210] In some embodiments the wires are braided with a closed loop 113 at the distal end 115 of the device as shown in
[0211] Optionally, in the unconstrained state the closed loop ends 113 may be bent inward toward the central axis to relieve forces and friction applied by the ends to the airway wall to reduce the risk of irritating the tissue which may cause granulation tissue or injury.
[0212] To accommodate lobar bronchi having an average circumference in a range of 22 mm to 44 mm multiple lobar valves may be provided. For example, a large size lobar valve may have a frame with an airway contact section having a diameter in a range of about 15 to 17 mm, preferably about 16 mm (a circumference of 50.24 mm), which may be intended to be placed in lobar bronchi having a circumference in a range of 31 mm to 44 m; and a smaller sized lobar valve may have a frame with an airway contact section having a diameter in a range of about 11 mm to 13 mm, preferably about 12 mm (a circumference of 37.7 mm), which may be intended to be placed in lobar bronchi having a circumference in a range of 22 mm to 33 mm. Note that the lobar valves may generally have a maximum unconstrained circumference that is larger than the circumference of the intended lobar bronchus (e.g., about 20 to 2.5 mm larger) so that when constrained by the lobar bronchus the airway contact section of the frame firmly contacts the airway wall and applies an outward radial force against the airway wall via the elastic properties of the structural frame and optionally other features described herein that contribute to radial contact force. The target airway may be measured using CT or other medical imaging or with a sizing device delivered through a bronchoscope.
[0213] The ratio of the maximum outer diameter of the airway contact section in an unconstrained expanded configuration to the maximum diameter of the constrained delivery configuration may be in a range of 3.8:1 to 7.8:1. Due to the relatively larger diameter and short length of lobar bronchi compared to higher generation airways, lobar valves may have a smaller length to diameter ratio in an expanded unconstrained state than current devices intended for more distal positioning. For example, a lobar valve may have a length in a range of 4 mm to 6 mm in its unconstrained state and a length to diameter ratio in a range of 0.545 to 0.286 (e.g., in a range of 0.5 to 0.25).
[0214] The structural frame along with the connected sealing membrane(s) in the delivery state may have a maximum diameter less than 2.7 mm (e.g., less than 2.6, 2.5, 2.4, 2.3, 2.2, 2.1 mm), preferably a maximum diameter of about 2.3 mm. Alternative embodiments of lobar valves may have different dimensions to allow them to be delivered through bronchoscope working channels having different diameters. Optionally, lobar valves in an unconstrained state may have a noncircular cross-section (e.g., ovoid, oval, irregular), which may have an improved fit in a bronchus having a noncircular cross-section. Alternatively, a lobar valve may be adapted to conform to a noncircular airway cross-section or irregular airway wall surface.
[0215] In situ, the structural frame may expand and contract with movement of the bronchus (e.g., during elastic recoil). The shape of the structural frame or use of its retention element may be resistant to tilting or may function properly when positioned in a range of angles with respect to the axis of the bronchus. Also, the structural frame may be compressed after it has been fully deployed allowing for repositioning. For example, a structural frame may be compressed by grasping or coupling a delivery tool to the frame's coupler and at least partially withdrawing it into a delivery sheath.
[0216] In its contracted delivery state, for example as shown in
[0217] Optionally or alternatively, a structural frame may be made from a bioresorbable material such as a polymer matrix (e.g., PLA, PLAGA, PDLLA).
[0218] Optionally or alternatively, a structural frame may be balloon expandable or made from a plastically deformable material such as plastic, cobalt chrome alloy, martensitic Nitinol, stainless steel, silicone or urethane.
[0219] Optionally or alternatively, a structural frame may be impregnated with an agent such as an antifungal, antibacterial, antimitotic, or anti-inflammatory agent that may improve patient response to implanting the device.
[0220] In these embodiments, the wall contact region 110 may be adapted to comply to lobar bronchi that have oval or irregular lumen cross sections; the device may comply to irregular airway surfaces creating a seal on surfaces having bumps, ridges, grooves or other non-smooth surface; the device may have an overall length that is suited for fitting in lobar bronchi.
[0221] The wall contact area 110 may have flexibility and elasticity to conform to non-cylindrical (e.g., irregular, oval, tapered, flared) or non-smooth (e.g., bumpy, ridged, contoured) airways or alternatively apply a greater contact force that causes the airway wall to deform or a combination of both in order to provide a continuous circumferential sealing band to prevent air leakage in to a targeted portion of the lung under pressure differentials normally experienced in the lung. When implanted in a target airway, a structural frame may be adapted to impart an outward contact force that may expand the airway wall no more than 20% which is expected to provide strong contact and a good air seal while avoiding trauma to the tissue that otherwise could cause excess formation of granulation tissue.
[0222] Optionally, a wall contact area 110 in its unconstrained state may be barrel shaped (e.g., have a wider middle than proximal and distal ends) or be flared (e.g., have a larger diameter distally than proximally), which may facilitate creating a good contact region and seal with the airway wall.
[0223] The wall contact region 110 of the structural frame 101 provides a scaffold for the membrane 102, which is affixed to the frame, for example by dip coating, adhesive, solvent bonding or other form of bonding. The structural frame may be collapsible to its contracted delivery state in an orderly fashion that does not damage the membrane.
[0224] Spokes
[0225] Optionally, a lobar valve may have radial spokes 116 that connect to the airway contact region 110 of the structural frame and extend inward toward the axis 118 where they may be connected to a hub or a coupler 109. In its compressed delivery state (
[0226] Coupler
[0227] The proximal end of the structural frame may comprise a coupler that mates with a delivery device that allows the coupler to transmit rotational and translational force from the delivery tool to the structural frame. The coupler may be used as a graspable protrusion to grasp with a bronchoscopic tool to manipulate the device during implantation, repositioning, or removal.
[0228] For example, a lobar valve 100 may optionally have a coupler 109, positioned at the proximal end 114 of the device, that functions to mate with a coupler of a delivery shaft 108 and release from the coupler of the delivery shaft upon actuation by a user. For example, the coupler may have a geometry (e.g., male or female threading) that mates with a coupler of the delivery shaft 108. An actuator (e.g., rotary dial, trigger, slider, button) controllable by a user for example on a handle connected to the delivery sheath and delivery shaft may control the delivery shaft and sheath to control release of the couplers (e.g., retract the sheath 105 and rotate the delivery shaft 108 to unscrew the mating coupler). When attached the coupler transmits motion of the delivery shaft to the implantable valve 100 including longitudinal translation distally, proximally and rotation around longitudinal axis 118.
[0229] In embodiments having spokes 116 a coupler 109 may also function to contain the terminals of the spokes.
[0230] Optionally, a coupler may be laser cut from a Nitinol hypotube, which may also form spokes and radially protruding retention barbs.
[0231] Covering/Seal
[0232] Lobar valves disclosed herein may further have at least one membrane (102 in
[0233] The membrane connected to the structural frame may be made from a thin, flexible, durable, foldable, optionally elastic material such as urethane, polyurethane, ePTFE, silicone, Parylene, Elast-eon™ or a blend of multiple materials. The membrane may be made by insert molding, dip coating or spray coating a mold or other manufacturing methods know in the art of medical balloon or membrane manufacture. It may be bonded to the frame for example by coating the frame, laminating over the frame, dip coating, spray coating, heat staking, bonding with adhesive, solvent bonding, or sewing. Referring to
[0234] The sealing membrane may be positioned and bonded outside the structural frame. Alternatively, a sealing membrane may have an inner membrane layer bonded to the inner surface of the structural frame as well as an outer membrane layer bonded to an outer surface of the structural frame wherein the inner and outer layers may be bonded to one another between braid wires or spokes 116 thus encapsulating at least a portion of the structural frame.
[0235] Airflow 120 as shown in
[0236] Portions of the sealing membrane 102 framed by wires of the structural frame in the airway contact region 110 may be flexible and have slack that functions to facilitate air sealing by billowing out and applying contact pressure with the airway wall over a surface area defined by the sealing membrane portions when air is passing through the device or a pressure difference is higher within the device.
[0237] The sealing membrane 102 and structural frame 101, in particular the wall contact region 110, form a contact surface area that is continuous around a circumference of a targeted airway.
[0238] In an alternative embodiment of a sealing membrane the membrane may have channels or openings that intentionally allow air to pass the seal in either direction initially after the device is implanted and gradually close to block air passage except for through a valve. For example, the channels may be positioned on the seal surface next to the airway wall and over time (e.g., a few weeks) become plugged with mucus that naturally exists in the airway. Gradual or delayed sealing could delay the evacuation of trapped air and subsequent lobar volume reduction so that shifting of the lobes of the treated lung occurs more gradually, which may be less likely to have adverse events such as pneumothorax or injury to healthy lung tissue.
[0239] Optionally, a membrane may deliver a chemical agent released slowly over time. For example, the membrane may deliver an antiseptic, antimicrobial or other agent, which may reduce the risk of infection, pneumonia, rejection or other complication. For example, a membrane may be impregnated with an agent such as an antifungal, antibacterial, antimitotic, or anti-inflammatory agent that may improve patient response to implanting the device.
[0240] Optionally, a membrane 102 may have a micropatterned surface that provides a non-stick or hydrophobic feature on the interior side (i.e., facing inward toward the axis 118) of the airway contact region 110, on the luminal covering section 119, on the valve, or a combination. The non-stick micropatterned surface may have a lubricious texture pattern which may reduce friction and repel or allow fluids such as mucous to slide off the membrane. The hydrophobic feature of the micropatterned surface may be created by nanostructures molded on to the polymeric membrane 102.
[0241] Optionally, a hydrophobic coating may be added to the interior side of the airway contact region 110, on the luminal covering section 119, on the valve, or a combination.
[0242] Optionally, a membrane 102 may have a micropatterned surface that provides increased hydrophilic character, friction or surface tension on the exterior side of the airway contact region 110.
[0243] One-Way Valve
[0244] The lobar valve 100 is adapted to provide a seal that does not allow air to flow, or at least substantially increases resistance to airflow through the targeted airway except for through the one-way valve 103. The sealing function is achieved by the membrane 102 connected to the structural frame and the sealing membrane 102 may also form the one-way valve 103. Alternatively, a one-way valve may be a separate structure bonded to the sealing membrane or structural frame. Generally, the one-way valve is adapted to allow air to flow at least predominantly in one direction, from the affected lobe and not into it.
[0245] Optionally, a valve material may be impregnated with an agent such as an antifungal, antibacterial, antimitotic, or anti-inflammatory agent that may improve patient response to implanting the device.
[0246] As an example, a one-way valve 103 may be made from a flexible, non-stick material such as an elastomeric material, urethane, polyurethane, ePTFE, silicone, Parylene or a blend of multiple materials. The one-way valve 103 may be a duckbill or Heimlich valve having a somewhat funnel shape that transitions from a distal flared end to a proximal closing end. The distal flared end may be tubular having an outer diameter that connects with the luminal covering region 119 of the sealing membrane 102. The distal flared end may have a diameter 121 in a range of 1 mm to 4 mm (e.g., 2 mm to 3 mm). The length 122 of the one-way valve 103 may be in a range of 3 to 8 mm (e.g., 5 mm). The Heimlich valve 103 includes a pair of opposed, inclined walls having ends that meet at lips at the proximal end. The lips meet at two opposed corners and may be pinched flat. The walls can move with respect to one another so as to separate at the lips and form an opening through which fluid can travel. When exposed to fluid flow in a direction represented by the arrow 120 in
[0247] Optionally, a one-way valve 103 may be adapted to provide a desired exiting air flow resistance. It may be desired to release air from the target lobe slowly to reduce a risk of pneumothorax that can be caused by rapid deflation of the lobe. Exiting air flow resistance may be inversely proportional to the valve's lumen diameter proportional to its length and may be a function of material stiffness.
[0248] Any of the lobar valve embodiments disclosed herein may optionally have a temporary reverse flow component that initially and temporary allows some air to flow from the proximal end 114 to the distal end. This feature may function to slow down the volume reduction of the targeted lobe to reduce a risk of pneumothorax associated with rapid deflation. For example, the feature may be a biodegradable or dissolvable component that hold the one-way valve 103 partially open or provide a gap between the airway contact region of a device 100 and the targeted airway wall. The component may shrink or dissolve over an initial duration of time (e.g., in a range of 3 days to 3 weeks).
[0249] Retention Mechanism
[0250] A lobar valve may have a retention mechanism such as radial contact force, radially extending barbs, a micropatterned surface on the membrane, placement distal to cartilaginous rings, radial interference, or a combination of these. The retention mechanism functions to keep the device situated and oriented in the targeted position of the patient's airway. The device may be removed by applying force (e.g., pulling, torqueing) to the coupling element or structural frame to overcome the retention force. Alternatively, the retention mechanism may be released from the airway by collapsing the lobar valve.
[0251] Radial contact force applied by the airway contact region 110 to the airway wall can help to retain the device 100 in the desired implant location in a lobar bronchus by contributing to friction. Furthermore, radial contact force may distend the airway wall creating a niche for the device to sit in. Radial contact force may be created by the elastic properties of the structural frame 101 returning to its shape set configuration, which may be larger (e.g., 5 to 20% larger) than the airway. Additional radial contact force may be created by optional spokes 116.
[0252]
[0253] A micropatterned surface on the polymeric membrane 102 at least in the airway contact region 110 may help to retain the device in place by resisting sliding on wet surfaces such as airway walls but not on dry surfaces such as through a delivery sheath. For example, a micropattern may be molded to the membrane using techniques known in the art (e.g., U.S. Pat. No. 8,720,047 assigned to Hoowaki, LLC). The micropatterned surface may increase water tension when contacting a wet surface which can greatly increase retention ability. The micropattern may have a plurality of pillars having height and width dimensions less than 1000 nanometers.
[0254] Placement of the device just distal to a cartilage ring in an airway may contribute to retention of the device. Cartilage rings exist in lobar bronchi in particular at the proximal end of lobar bronchi and may protrude from the airway surface where cartilage rings are absent. Since the structural frame is shape set to a larger size than the airway it elastically expands against the airway wall. To overcome the cartilage ring, the structural frame would have to reduce in size which goes against its elastically expanding nature.
[0255] As shown in
[0256] Alternatively, barbs 104 may be made from a laser cut hypotube. For example, a coupler, spokes and barbs may be made from a laser cut hypotube, wherein the spokes are connected to a braided structural frame forming an airway contact region.
[0257] Regardless of the retention mechanism embodied, a lobar valve 100 may be implanted and before removing the delivery tool and bronchoscope, a pull force test may be applied to the device to ensure it has been sufficiently anchored in place. With the delivery tool connected to a grasping mechanism of an implanted lobar valve, the pull force may be conducted by applying a gentle pull force on the delivery tool. A force gauge may indicate the amount of force applied to the lobar valve. If the valve becomes dislodged below a predetermined force, the retention mechanism of the stent may not suit the current implantation, a different sized device may be required, or the device may need to be repositioned.
Example Embodiment 1 Braided Frame with Spokes
[0258] A first embodiment of a lobar valve as shown in
[0259] The wires of the braided structural frame 101 have closed loop ends 113 on the distal side 115 and on the proximal side 114 the wires are gathered and shape set to form the spokes 116. The terminals of the wires are held (e.g., crimped, welded) in the coupler 109.
[0260] Barbs 104 radially protrude from the proximal end of the airway contact region 110.
[0261] Relative to the airway contact region 110, the spokes 116 may be angled proximally 114 as shown in
[0262] Optionally spokes 116 may be “S” shaped spokes 155 as shown in
[0263] Alternatively, as shown in
[0264] Alternatively, spokes and optionally a coupler or radial barbs may be made from a laser cut hypotube (e.g., Nitinol).
[0265] The optional barbs 104 may be formed from a variety of options disclosed herein such as separate wires from the braided structural frame connected to the spokes or airway contact region, wires forming the braided structural frame cut and shape set to protrude forming the barbs, or portions of the braided structural frame shape set to protrude outward.
Example Embodiment 2 Braided Frame with Tapered Proximal End
[0266] An alternative embodiment 180 of a lobar valve is shown in
Example Embodiment 3 Braided Frame Open on Both Ends
[0267] Another alternative embodiment of a lobar valve 205 is shown in
[0268] Optionally, as shown in
Example Embodiment 4 Braided Frame Closed on Both Ends
[0269] Another alternative embodiment of a lobar valve shown in
[0270] A sealing membrane 241 may be connected to the braided structural frame at least partially over the airway contact region 232 and a portion of the proximal luminal covering region 234 leaving an uncovered part 242 of the luminal covering region 234. A separate membrane flap 243 connected to the coupler 109 or structural frame temporarily covers the gap 242 and overlaps a portion of the membrane 241 when air pressure is higher on the proximal end 114 than the distal end 115. The flap 243 opens when pressure is higher on the distal end 115 than the proximal end 114. Thus, the flap 243 and membrane 241 act as a one-way valve.
[0271] Alternatively, the membrane 241 may partially cover the distal luminal covering region 238 and a one-way valve may be formed with a flap at the distal end also adapted to preferentially allow air flow from the distal to proximal ends (not shown).
[0272] Optionally, the membrane 241 at least on the exterior portion of the airway contact region 232 may have a molded micropattern 244 to increase retention in the airway.
[0273] Optionally, radially protruding barbs 245 may be connected to the braided structural frame 241. The barbs 245 may be one or more of the various embodiments of radially protruding barbs disclosed herein.
[0274] The braided structural frame forming both proximal 234 and distal 238 luminal covering regions may have increased strength or radial contact force with the airway wall in situ.
Example Embodiment 5 Braided Frame Forming an Inner and Outer Tube
[0275] Another alternative embodiment of a lobar valve 260 is shown in
[0276] A sealing membrane 268 may be connected to the braided structural frame 261 on at least a portion of the airway contact region 267, where the membrane may optionally have a micropatterned surface on the exterior of the membrane to enhance retention in an airway. The membrane may also cover the luminal covering region 264 and form a one-way valve 269 (e.g., Heimlich or duckbill valve) in a lumen defined by the inner tube 266.
[0277] The embodiment shown in
[0278] Delivery Tool
[0279] As shown in
[0280] An alternative embodiment of a delivery shaft, may have a central lumen, which may be used for delivery over a guidewire or to pass over or deliver other instruments such as an endoscope. Optionally a delivery shaft may have a mandrel extending distally, which may be used to hold a valve to the delivery shaft, to add coupling force, to target a coupler of a lobar valve when retrieving it or to adjust its position.
[0281] Optionally, the delivery tool may have a delivery sheath 282 used in conjunction with the delivery shaft 280. The sheath may constrain the valve in a delivery state during delivery through a working channel as shown in
[0282] Optionally, the delivery tool may have a handle 283 at a proximal region that has an actuator (e.g., thumb lever) that controls a sliding translational movement of the shaft 280 with respect to the sheath 282 facilitating one-handed control for advancing a valve out of a sheath or retracting it into the sheath. For example, a sheath 282 may be connected to the handle body and a shaft 280 may be slidably engaged in the sheath and connected to a gear that is movable (e.g., rotation or translation) within the handle and moved by a mating gear connected to an actuator such as a thumb lever, slider, or rotary dial. The handle may have one or more actuators that move the delivery shaft and control the position of the lobar valve from a fully contained position as shown in
[0283] Kit
[0284] Optionally a lobar valve may be provided preloaded in a delivery sheath, optionally disposable, in its constrained delivery state and coupled with a delivery shaft as shown in
[0285] Delivery
[0286] A method of use may involve the following delivery steps:
[0287] From a CT scan, measurements are taken to confirm intended valve placement location, target airway diameter and length;
[0288] An appropriately sized lobar valve is chosen to match the measured airway size.
[0289] The lobar valve is visually inspected prior to loading into a delivery sheath;
[0290] A bronchoscope is advanced through the patient's endotracheal tube to the targeted lobar airway;
[0291] The lobar valve in the delivery sheath is advanced distally through a working channel of the bronchoscope;
[0292] The distal end of the delivery system is advanced distally out of the working channel to a desired valve position in the target airway;
[0293] While holding the bronchoscope in position relative to the airway the delivery sheath is retracted proximally relative to the shaft and lobar valve to deploy the lobar valve to its expanded but coupled position;
[0294] The position, fit, alignment, and seal may be visually inspected through the lens of the bronchoscope. The delivery system may be pulled gently to confirm mechanical anchoring or engagement of the valve against the airway wall;
[0295] If position, fit, alignment, seal and anchoring are not satisfactory optionally push or pull the delivery system to adjust;
[0296] If position, fit, alignment, seal and anchoring are still not satisfactory retract the lobar valve at least partially back into the delivery sheath;
[0297] The delivery sheath and lobar valve may be repositioned and redeployed;
[0298] If the position, fit, alignment, seal and anchoring are satisfactory the lobar valve may be disengaged from the coupler of the delivery system;
[0299] The delivery system may be removed from the patient;
[0300] The lobar valve may be visually inspected through the lens of the bronchoscope;
[0301] The bronchoscope may be removed from the patient.
[0302] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.