Patent Application
20190321050
The field of the invention is lung reduction devices used to treat chronic obstructive pulmonary disease (COPD). In particular, the invention relates to lung reduction devices configured to be delivered through the airway to the lung with minimally invasive techniques.
COPD is a lung disease that makes it hard to breathe. COPD can cause coughing that produces large amounts of phlegm or mucus, wheezing, shortness of breath, chest tightness, and other symptoms. Cigarette smoking is the leading cause of COPD, but long-term exposure to other lung irritants, such as air pollution, chemical fumes, or dust, may contribute to COPD. COPD is a progressive disease which gets worse over time, such as over the course of several years.
To understand COPD, it helps to understand how the lungs work. Air drawn in through the nose or mouth when drawing breath goes down the windpipe into tubes in the lungs called bronchi or airways. Within the lungs, the bronchi branch out into thousands of smaller, thinner tubes called bronchioles. These tubes end in bunches of tiny round air sacs called alveoli. Small blood vessels called capillaries run through the walls of the air sacs. When air reaches the air sacs, oxygen passes through the air sac walls into the blood in the capillaries. At the same time, carbon dioxide (a waste gas) moves from the capillaries into the air sacs. This process is called gas exchange. Typically, the airways and air sacs are elastic and may stretch to accommodate air intake. When a breath is drawn in, each air sac fills up with air like a small balloon. When a breath is expelled, the air sacs deflate and the air goes out. The expansion and contraction of the air sac are critical to the gas exchange. Air sacs that are free to expand exchange more gas than air sacs that are constricted or prevented from fully expanding.
In those with COPD, less air flows in and out of the airways because of one or more of the following: the airways and air sacs lose their elastic quality; the walls between many of the air sacs are destroyed; the walls of the airways become thick and inflamed, and the airways make more mucus than usual, which can result in mucus buildup and airway blockage.
In typical cases of COPD, the disease does not equally affect all air sacs or alveoli in a lung. A lung may have regions in which the air sacs are damaged and unsuited for gas exchange. In severe cases, these regions may be large, such as 20 to 30 percent or more of the lung volume. Thus, large regions of the lung may be damaged and unable to effectively perform the gas exchange. Alternatively, the damaged regions may be small islands of air sacs disbursed throughout the lung.
The effects of COPD are typically most debilitating when a patient exercises or engages in other physical excretion that would cause a healthy patient to breath heavily. A patient with COPD may not be able to breathe heavily because the diseased portions of the lung trap air that then results in the inability to exhale, or breathe out. This, in turn, prevents the subsequent expansion of healthy lung portions to their optimal size. During exercise or other physical exertion, the lung(s) of a patient affected by COPD may operate in dynamic hyperinflation of the lung(s), which impairs respiratory mechanics, and increases the work of breathing Hyperinflation of the lung may also hinder cardiac filling, lead to dyspnea and reduce exercise performance of the patient. The detrimental effects of COPD often lead to a cascade of symptoms that eventually impairs quality of life and increases the risk of death of the patient
In the United States, the term COPD includes two main conditions, which are emphysema and chronic bronchitis. In emphysema, the walls between many of the air sacs are damaged. As a result, the small airways and air sacs lose their structural integrity and the ability to maintain their optimal shape. This damage also can destroy the walls of the air sacs, leading to fewer, but larger air sacs instead of the many small structures found in healthy lung tissue. When this destruction occurs, the amount of gas exchanged by the alveoli of the lungs may be significantly reduced. Within the lung, focal or “diseased” regions of emphysema, characterized by a lack of discernible alveolar walls, are referred to as pulmonary bullae. Within diseased lung, these inelastic pockets (>1 cm in diameter) of dead space do not contribute to gas exchange and are often considered to be primary candidate areas for therapy.
In chronic bronchitis, the lining of the airways becomes inflamed, generally as a result of ongoing irritation. This inflammation results in thickening of the airway lining and the production of a thick mucus, which may coat and eventually congest the airways of the lung. It is common to find patients with COPD having symptoms of both emphysema and chronic bronchitis.
COPD is a major cause of disability and is the third leading cause of death in the United States. Millions of people are diagnosed with COPD. Many more may have the disease and may be unaware of the progression of the disease, as COPD develops slowly, such as over the course of many years. Symptoms often worsen over time and can limit the ability to do routine activities. Severe COPD may prevent a patient from doing even basic activities like walking, climbing stairs, or taking care of oneself Currently, there is no cure to COPD, and while research is ongoing, current medical techniques offer no solution for reversing the damage to the airways and lungs associated with the disease.
Fortunately, there are treatments and lifestyle changes can help reduce the symptoms of COPD, allow patients to stay more active, and slow the progress of the disease. Reducing the increase of risk of COPD from smoking is considered to be the most effective lifestyle change. As a more drastic approach, one treatment that temporarily addresses the symptoms of COPD is Lung Volume Reduction Surgery (LVRS), which surgically removes poorly functioning portions a lung (typically up to twenty to thirty-five percent). By removing relatively diseased portions of a lung, LVRS reduces the overall size of the lung and opens the volume within the chest for the remaining lung to expand and contract. The remaining lung is elastic and able to expand into the newly opened volume of the chest. LVRS improves the capacity of the lung to breath by allowing the remaining portion of lung to expand and contract to a greater extent than before LVRS. Thus the remaining lung has an enhanced capacity to take in air and exchange gases. The obvious drawback is that LVRS is highly invasive and requires open-lung surgery, rendering it only a last-resort option for many patients.
Although LVRS has benefits, as compared to other optimized medical therapy, the risks and mortality/morbidity rates of LVRS require serious consideration before surgery. Up to twenty eight percent (28%) of patients have been reported to need in-hospital stay for rehabilitation facilities for one (1) month or more after surgery. Main factors of LVRS-related morbidity include adverse effects of general anesthesia during surgery, mechanical ventilation during surgery and the fragile clinical status of patients with advanced emphysema. That said, conceptually, the removal (resulting in the overall reduction) of emphysematous lung tissue in LVRS increases the available volume in the chest cavity, within which the remaining portion of the lung may expand. The greater expansion of the remaining lung tissue stretches the tissue to a greater extent than the tissue expanded before LVRS. By effectively restoring the elastic recoil of the lung tissue in some parts of the lung, airway traction is at least temporarily improved and the symptoms of airway closure within the lung may be delayed significantly.
To achieve the benefits of LVRS with a lower morbidity rate and length of recovery/hospital stays, the minimally invasive techniques and devices have been developed, with varying degrees of success. These techniques may include inserting, deploying and activating lung reducing devices with a lung via the trachea of the patient. These techniques do not require an open, surgical approach, and are envisioned to require minimal general anesthesia (or only a reduced period of general anesthesia or conscious sedation). Recovery time and hospital stays that result from these minimally-invasive devices, applications or techniques would also be dramatically reduced as compared to LVRS.
Examples of less invasive devices and techniques for lung volume reduction are shown in U.S. Pat. Nos. 6,599,311, 7,128,747 and 8,157,837, and in Kontogianni, “BRONCHOSCOPIC NITINOL COIL LUNG REDUCTION DEVICEATION: A NEW LUNG VOLUME REDUCTION STRATEGY IN COPD”. Respiratory, EMJ European Medical Journal, p. 72-78 (October 2013). The lung reduction coils are deployed to fasten primarily to poorly performing regions of the lung. As the devices expand, bend, retract or otherwise change shape, they seize the attached portion of the lung and physically compact lung tissue. This action collapses the lung tissue affixed to the device, as well as additional tissue along the path of the device, surrounding the thereby reduce the overall size (and volume) of the lung similar to LVRS.
While the above-mentioned devices and methods and traditional LVRS demonstrate that there is a basic correlation between a reduction in unhealthy lung volume and improvements in patients suffering from emphysema, the current limitations of these approaches suggests that vast improvements are yet to be made in order to fulfill a need in the current state of the art.
Minimally invasive surgical techniques for lung reduction and lung reducing devices have been shown, at times, to be effective in human patients. The devices have yet to enter into widespread use. While the lack of use is at least partially due to the lack of government approval in the United States, it is posited that existing lung reducing devices and the techniques to implant the device do not represent optimal solutions for lung reduction. The inventors have identified a need for lung reducing devices that are safe, easy to deploy, reliable and capable of cumulatively collapsing large portions of a lung, for example at least fifteen to twenty percent (>15-20%) of the overall volume of the lung.
The inventors have 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 and surgical techniques. The lung reducing devices may be used to reduce the volume of one or more lung, thereby increasing the elastic recoil of the remaining lung volume.
These devices may also delay closure of the small airways in the lung during a breath and lower the Residual Volume (RV) in the lung. A reduction in RV results in less air trapped in the lung at the end of each breath and suppresses hyperinflation of the lung. These improvements to lung dynamics may contribute to a reduced strain in breathing and a reduced sense of dyspnea.
RV is an accepted index of disease severity and the benefit of a lung reduction therapy is generally accepted to be proportional to the reduction in RV. Reduced thoracic gas compression and improved expiratory flow may translate to an improvement in chest wall and diaphragm configuration and mechanics, reduced dynamic hyperinflation and strain of breathing, and better cardiac performance.
A novel treatment is disclosed herein for patients suffering from COPD comprising the application of a minimally invasive bronchoscopic technique to implant a lung reduction device into a lung airway of a patient. The implantable lung reduction device, which may be generally referred to as a “clip” roughly comprises two or more distal arms that are envisioned to span adjacent airways. The arms of the device are connected or joined at a device body immediately upstream of the bifurcation (also referred to as a “fork”) in the airway, with the device body defined beginning from the upstream (proximal) end of the device through to the distal-most intersection of the arms or the device saddle. The tissue separating the two adjacent airways immediately downstream of the airway junction may be referred to as the airway septum. The device may bias the tissue of the septum together to affect the airway passages and the overall lung volume downstream of the bifurcation. The biasing of the tissue compressed and collapses, at least partially, the lung tissue in the vicinity of the adjacent airways and the bifurcation. The overall lung volume is reduced due to the local tissue collapse. Implanting several devices (i.e. 10, 15, 20 or more), implanting devices within a single lobe, or staging delivery of lung reduction devices provides a cumulative reduction that may amount to 10%, 20% or more of the volume of the lung.
The lung reduction device configured for delivery may be a clip, fork, clamp, clasp, pin device or other device. In some embodiment, it is envisioned that the device may be dimensioned to pass within a channel along the interior of a delivery device. The working channel of a scope dimensioned and configured for passage through or directly within the trachea 10 may be used within such a delivery system. The device is further configured to, when deployed, collapse two or more downstream branches of the lung airway by biasing the branches towards one another. One challenge that faces the use of implantable lung reduction devices is the positioning and delivery of the device. It is envisioned that procedures involving lung reduction device delivery to a lung directly through the trachea or with a modified bronchoscope would be minimally invasive, reliably safe and would have the potential to become the preferred procedure to treat COPD. At least one such delivery system for a lung volume reduction device is described herein. The delivery system safely delivers the lung reduction device to the diseased portion(s) of the lung.
In at least one aspect, a bronchoscope delivery system may be inserted through the trachea to insert the lung reduction device(s) into the lung airway. The lung reduction device may be deployed using a standard, adapted or modified bronchoscope. A bronchoscope is a device used to pass through the trachea and inspect the lung parenchyma or pleural space. Bronchoscope procedures are common, minimally invasive and safe. In some instances, it may be further advantageous to perform bronchoscopic delivery, as some practitioners prefer one or more systems of feedback to assist in the delivery process. The bronchoscope may be a carrier for a sterile and disposable delivery system for the lung reduction device. The delivery system may further comprise a catheter, a guide wire, and a mechanism for delivery and deployment and possibly retrieval of the lung reduction device(s).
In at least one further aspect, the delivery system may include a guide wire, a catheter and a delivery tool at a distal end of the catheter. The guide wire serves as a specialized guide for the catheter, which is used by the surgeon to identify and select a pathway through the lung airway and bifurcations in the lung airways to treat. The movement of the guide wire through the airways may be viewed on display screens connect to X-ray fluoroscopy device or computed tomography scanners (CT scanners) imaging the chest of the patient. The guide wires also support the catheter, as the catheter is maneuvered through lung airways to the selected bifurcation. The guide wire may also be used to help determine the appropriate length of the lung reduction device.
In at least one aspect, a catheter functions as a conduit to deliver the lung reduction device from outside the patient to the targeted treatment area. The catheter can also be used to re-position or remove the lung reduction device. The lung reduction device may be removed by reversing the methods of the deployment procedure Alternatively, in at least one aspect, the lung reduction device may be retracted into a tubular sheath that would be extended from the catheter, and the catheter/sheath combination may then be safely retracted from the airway possibly through the working channel of the bronchoscope.
Using a wide range of medical imaging techniques suitable for the chest cavity and lung, a physician may select an airway bifurcation, as a target to approximately seat the device body of lung reduction device. The distal end of the delivery system may be loaded to contain the lung reduction device and is subsequently extended towards the selected airway bifurcation in the downstream direction. The lung reduction device may have a device body connected to at least two arms that extend distally away from said device body. The device may have a reduced profile for delivery, wherein in the reduced profile the device is capable of being advanced downstream or distally into a small airway of the lung. The device may also be configured to assume an expanded profile once deployed within the airways of the lung, wherein the expanded profile the device secures to lung tissue.
Sufficiently reducing lung volume in at least one or more lobes in the lung is critical to the operation of the device. The dimension and configuration of the device must be advantageous for both delivery and use in collapsing unhealthy lung tissue. Generally, the device body comprises a stem, which may be configured to face upstream and interact, as necessary, with the delivery tool of the delivery system (e.g. a grasper, or pusher or other device that may be extended from a bronchoscope). Opposite the stem, the device body comprises a vertex that may be configured to face in the downstream direction. The profile of the device is generally affected by the shape and angle at the vertex of the body. At the vertex of the body, the device body splits into its respective distally-extended arms. The device may further comprise a saddle at or near the vertex of the device body. In some instances, the saddle may also be located at the vertex, but in more complex configurations the saddle and vertex may be separate from the other. The saddle be suitable and specifically configured for extended contact with the septum, the tissue immediately downstream of the airway bifurcation. In more complex devices, the saddle is found immediately downstream of the distal-most intersection of the arms. Alternatively, when the device or devices are placed, the saddle is located immediately upstream of a respective septum.
The tissue of the septum at or near the bifurcation may serve as both a target for device delivery and/or a physical stoppage and fixation point for the lung reduction device, as access to the area can be visually confirmed and where the tissue therein is relatively devoid of blood vessels. These tissue characteristics may help to reduce injury, inflammation, bleeding and other risks associated with implantation, which are increased, as result of the bias imparted by the arms of the device. The device may be seated on the saddle of the device, within the lung airway immediately upstream or adjacent to the tissue of the septum. With the device body and saddle seated over the septum 28 and with the arms positioned within the branches, the lung reduction device may elastically bias the airways in the direction of the other arm, narrowing the lung tissue held between the airways containing the arms. In alternate embodiments, further manipulation of the device may be needed to create the appropriate biasing force needed to close the arms and compact their respective airways.
A novel method is disclosed for minimally or non-invasively reducing the volume of one or more hyperinflated lungs, and improving the pulmonary function of a patient with chronic obstructive pulmonary disease, including through reducing the volume of one or more hyperinflated lungs, removing trapped or residual air from the lung and increasing the metabolic efficiency of the thoracic diaphragm. Diseased lung tissue is frequently made of the inelastic pockets that both contain significant portions of trapped air and lack the ability to contribute to gas exchange and may be identified using various medical imaging techniques to direct therapy to candidate lung areas for therapy.
Based on patient need, practitioner preference, or other factors, the lung reduction device, delivery device and methods may be selected from one or more of the alternative lung reduction devices and methods of use described herein. For example, a surgeon may be presented with lung reduction devices of various sizes, e.g., length of the legs, and biasing force (force applied by the clip to close the legs of the clip). The surgeon implants each of the selected devices during the course of a lung reduction surgery.
A novel method is disclosed to reduce the size of a lung comprising: inserting a bronchoscope into the patient airway, advancing the bronchoscope distally into the patient lung, identifying disease/targeted tissue or the airways leading to the targeted area of lung parenchyma, and navigating the bronchoscope to the selected airway. Once placed, the catheter and guide wire may be sequentially placed into the working channel of the bronchoscope, advancing the guide wire out of the working channel and into the targeted airway, holding the guide wire fixed relative to the bronchoscope and advancing the catheter distally as far as possible but generally not past the tip of the guide wire, possibly removing the guide wire from the catheter while maintaining the catheter position, abutting the proximal end (e.g. stem) of the lung reduction device with the delivery mechanism (e.g. a delivery tool, grasper or gripper), inserting the lung reduction device in the delivery configuration into the catheter and by advancing the delivery tool and the lung reduction device, positioning the lung reduction device into the target airway and deploying the lung reduction device, and further verifying the position of the lung reduction device prior to releasing the lung reduction device. A delivery tool may be coupled to, contact, or abut the proximal end (e.g. the stem) of the lung reduction device to deliver it through the catheter providing control of delivery and deployment of the lung reduction device. The guide wire and the catheter may continue to be used to deploy additional lung reduction devices.
In some embodiments, interaction with the bronchoscope wall, an optional delivery sheath, other feature of the delivery device, or environmental features (e.g. tissue or airway walls) may spread the arms of the device during delivery. In one embodiment, the walls of the septum force open the arms of the device, allowing the arms to advance downstream into lung airways. The tissue between the airways is compressed by the arms of the device. Alternatively, the delivery sheath may be retracted to allow the arms to separate controllably to allow for positioning over the septum 28. With the arms separated, the device is advanced downstream into the lung airway to further position arms within the branches of the bifurcated airway(s). The device may employ additional features to increase the bias of the arms following the positioning of the device. The catheter, delivery features and/or other devices used to position the lung reduction device are completely removed after fully positioning the lung reduction device.
In some embodiments, as each generation (branch) of airways generally decrease in diameter at it extends distally into the lung, the method may further comprise selecting bronchoscope and catheter with diameters sufficiently narrow to navigate the patient airway up to, but not beyond the septum of the target area. By advancing the delivery devices to the airway just upstream of the target area and septum, the device may be delivered using the septum as a both visual guide and physical barrier, drastically increasing the potential speed of device placement, while also mitigating many of the risks of device implantation.
Several lung reduction devices may be implanted throughout the patient lung or lungs, targeting one or more pairs of airways at each point. The combined effect of the lung reduction devices is to collapse a large portion (e.g., ten (10%) to thirty (30%) percent of the lung). In some instances, the lung reduction device may be manipulated by a handle, which is grasped and released by a surgical insertion tool, such as a tool introduced through the distal end of a bronchoscope or catheter. The lung reduction devices may be supplied in different sizes, each of which may have a different length of the arms or compression strength. The different sizes may be selected to accommodate anatomical variations of airways, or to restrict entry to specific generations of airway. The lung reduction device may be designed to be biocompatible, atraumatic and configured to remain implanted in the small airways of the lung for extended periods of time.
The intended physiological benefit of the lung reduction devices is similar to the desired effect resulting from LVRS, which is to reduce the volume of a lung by collapsing regions of the lung tissue (parenchyma) that are diseased and are not effectively exchanging gases between air and blood. Lung reduction is achieved by the lung reduction devices bringing the branches of the airway closer together and compressing the diseased lung parenchyma between the airway branches. The lung reduction devices may also apply tension to relatively healthy, and well-functioning lung tissue near the collapsed airways. This increase in tension may help to increase the elastic recoil of the remaining lung tissue. Also, collapsing diseased lung tissue redirects air in the lung to healthier portions of the lung.
As a result of volume reduction in the lung, small airway closure may be delayed during expiration, may occur at lower RV, and may result in less air trapping. A reduction in RV subsequently results in less hyperinflation. This cascade may contribute to increasing the efficiency of breathing and reduced common symptoms of lung hyperinflation, specifically the sensation of shortness of breath (dyspnea). This therapy may target specific and local diseased regions of the lung, which in some cases may be identified by imaging, but may also be considered for use in treating the symptoms of a homogeneous emphysema, wherein most of the lung is affected. It is expected that one or more than one lung reduction devices may be necessary to achieve adequate therapeutic effects and that such devices can be added and removed, as needed.
In accordance with these and the further aspects of the present invention, a method and device is described for reducing the volume of a lung. The present invention provides advantages of a minimally invasive procedure for alleviating at least some of the symptoms associated with COPD and emphysema without the risk and complications associated with conventional LVRS surgery.
Other advantages of this invention are made apparent in the following descriptions taken in conjunction with the provided drawings wherein are set forth, by way of illustration and example, certain exemplary embodiments of the present invention wherein:
Air inhaled from the environment initially enters through the mouth or nose, passes the larynx, and is carried down through the trachea 10 (or the wind pipe) into the lungs 30. The conducting airways of the lungs begin at the tracheal bifurcation 22. The lung airways 24, which are long tubular structures that conduct air through the respiratory tract, include the first generation (or primary) bronchi 12, commonly known as the right or left bronchus, that lead air into each of the lungs where they subdivide into secondary bronchi 14. Each second generation (or secondary) bronchus 14 then leads into a single lobe where it subdivides further into tertiary bronchi 16. These tertiary bronchi lead into each of the pyramid-shaped bronchopulmonary segments (not shown), which are separated from one another by connective tissue septa. Each of these bronchopulmonary segments supplied by bronchi 12, 14, 16 is served by a corresponding artery and vein. Blood supply to these segments is clinically important as pulmonary disease is often confined to one or a few unhealthy segments, which can be treated (e.g. surgically removed, compressed, or otherwise reduced in volume) with minimal effect on the overall function of the remaining healthy segments.
Within the bronchopulmonary segments, branches 25 of the airway 24 divide from the tertiary bronchi in several generations of numerous smaller bronchioles 18. Weibel (1963) observed twenty three (23) successive branches 25 of conducting airways 24 ranging from the trachea 10 through to the terminal bronchioles in the normal human respiratory system. The branches 25 of the conducting airways 24 lead into the respiratory zone of the lungs, which are comprised of respiratory bronchioles, alveolar ducts and alveoli 20. The alveolar ducts lead into a terminal branch or into alveolar sacs, clusters of individual microscopic structures known as alveoli 20 (see details of
As a person breathes in air from the environment, the alveoli 20 stretch, drawing oxygen in and transporting it into the blood. Simultaneously, carbon dioxide is removed from the blood. During the process of exhalation, the alveoli contract, forcing carbon dioxide out of the body. To optimally perform their function, alveoli 20 must maintain their expandable surface area, structural integrity and overall elasticity. Emphysema is a condition that involves damage to the walls of the alveoli of the lung. In emphysematous lungs, the alveoli and lung tissue are gradually destroyed. As the disease progresses, the walls separating the alveoli are reduced, resulting in a loss of surface area and elasticity diminishing the ability of the lung parenchyma to properly support airways 24. Bronchioles eventually collapse and cause an obstruction to exhalation, which traps air inside the alveoli.
While different muscles groups contribute to inhaling and exhaling, the largest and most efficient muscle that plays a role in breathing is the thoracic diaphragm, known simply as the diaphragm. The diaphragm is a large muscle that lies under the lungs 30 and separates them from the organs of the abdominal cavity below, such as the stomach, intestines, liver, etc. As the dome-shaped diaphragm 40 contracts, it moves down (descends) like a piston in a cylinder, it flattens, the ribs flare outward, the lungs expand and air is drawn in through the airways 24. This process is called inhalation or inspiration. As the diaphragm relaxes, the lung 30 contract to their original position expelling air from the system urged by elastic recoil of the lung tissue. This is called exhalation or expiration. The lungs, like balloons, require energy to expand but no energy, other than the stored energy of elastic recoil, is normally needed to let air out. Additional muscles that are used in breathing are located between the ribs (e.g. intercostal muscles) and among certain muscles extending from the neck to the upper ribs. The diaphragm, muscles between the ribs and one of the muscles in the neck called the scalene muscle are involved in almost every breath.
To help monitor the health and function of the lungs, as well as the progression of deterioration or disease states, the evaluation of lung volumes provides a tool for understanding the changes that may occur in lung mechanics The breathing cycle is initiated by expansion of the chest. Contraction of the diaphragm causes it to flatten and move downward. If chest muscles are used, the ribs expand outward. The resulting increase in chest volume creates a negative pressure that draws air in through the nose and mouth. Normal exhalation is passive, resulting in recoil of the chest wall, diaphragm, and lung tissue.
Table of
The terminal bronchioles are only a single generation removed from respirator bronchioles, which lead directly to the alveolar duct and alveoli 20. The generations of interest for delivery and use of the device may be the intermediate generations. For example, according to these observation, up to eight lung reduction devices can be inserted into the distinct branches of 4th generation airway as it splits into the 5th generation. The use of these device in a single unhealthy lobe of the lung would decrease the volume of that lobe, allowing the remaining healthy portions of the lung to function more efficiently.
A lung reduction device to be implanted into the divisions of the lung may be dimensioned to access at least the 5th, 6th or 7th generation of the lung. The distal ends of the devices may be tapered, in some embodiments, to accommodate natural narrowing of the airways towards distal end. These distal ends, in the form of arms extending away from a device body, can be narrow in diameter near the device body (e.g. narrower than the diameter of the preceding generation, less than 2 mm, or less than 1 mm) and vary in length from approximately 10-3 mm long.
The devices and methods of providing a minimally invasive lung volume reduction system allows for a treatment option that is available to patients suffering from late-stage pulmonary disease and emphysema. A lung volume reduction system may comprise a lung reduction device designed to be delivered to a lung airway 24 of a patient in a delivery configuration and deployed to compress unhealthy lung tissue 50, thereby improving the function of the remaining healthy tissue.
The stem 124 of the lung reduction device supports an optionally rounded proximal end, which is abutted or gripped by a delivery tool 108. The delivery tool 108, e.g., rod, graspers or gripper, may affect the device body at the proximal end, at the rounded end of the stem 124, of the lung reduction device 120. The contact with the proximal end of the device at least facilitates advancement of the lung reduction device into the catheter and into the airway 24. In its simplest form, the delivery tool 108 may be a rod or shaft extending through the catheter 106 and may be attached to a distal end of a bronchoscope or extend through a channel inside the bronchoscope within a catheter to a proximal end of the scope outside of the patient accessible to the operator. The delivery tool 108 on the distal end of the delivery device may close to clamp onto the rounded proximal end of the lung reduction device and open to release the stem 124.
It is envisioned in at least one embodiment that a collar, slideably received and surrounding both arms of the device, may be advantageous in both the delivery and use of the device. The collar 116 (not shown in
Alternatively, the release or delivery of the device may be actuated by sliding an optionally delivery sheath distally from the delivery tool 108 and onto the saddle of the lung reduction device. The sleeve may hold the delivery tool 108 closed and the delivery tool 108 may be biased opened such that the delivery tool 108 opens when the sleeve is off the delivery tool 108. If a sheath is used, it may be positioned along the lung reduction device 120 and envelope the lung reduction device 120 from the proximal to the distal end. The sheath may also envelope the delivery tool 108 while the lung reduction device is being positioned adjacent the saddle and the arms 122 are closed to collapse the diseased tissue 50 adjacent the septum 28 and between branches of the airway 24.
Once the lung reduction device is positioned with the arms in the branches and the saddle adjacent the selected septum 28, the sleeve is retracted away from the septum 28 past the rounded end of the stem 124 (and allows the delivery tool 108 to be opened and release the stem) and over a proximal end portion of the arms 122 to force the arms to close and thereby collapse the branches. Resulting from the retraction of the sleeve and the release of the delivery tool 108, the lung reduction device is fully implanted and released from contact with the delivery tool and the device has collapsed two or more branches to reduce the volume of the tissue 50 located substantially between these branches.
The arms 122 of the lung reduction device that extend distally may be elastic and biased to alter the shape, orientation and forces exerted by the device (i.e through the device arms) during device delivery or once the device is deployed.
Maintaining a device in a compressed position may also provide advantages. As the device is reoriented or manipulated to have reduced dimensioned, device delivery may be facilitated by this compact configuration. Once deployed, compressing the device by altering the device configuration or by attaching additional locking mechanisms may increase the biasing force through the arms of the device. In an alternative or in combination, the at least one part of the device delivery process may be favorable under a neutral or expanded position. Contrary to the compressed position, a neutral or expanded position would allow the arms of the device to gather and surround the maximum volume of septum tissue with very little resistance. It is envisioned that a device could utilize all three relative positions to maximize the benefits of each described herein.
In at least one envisioned embodiment, each device has two or more arms. The arms 122 may be made of stainless steel, titanium, nitinol, plastic, ceramic or other implantable and lung compatible material. The material forming the arms and nub may be the same as the material forming the stem. Further, the arms, nubs and stem may be a single piece forming the lung reduction device 120. The arms 122 may be symmetrical along the length of the lung reduction device. The arms in each device may closed together to impart a uniform compression on the branches or the arms 122 may be asymmetrical to conform to the branches and facilitate compact collapsing in the delivery configuration.
In at least one envisioned embodiment, a device comprises a device body with a vertex and a saddle, a first arm connected to the device body, and extending distally away from the device body, and a second arm connected to the device body and extending distally away from the device body, wherein the first and second arms are connected to the device body at the device body vertex, and wherein the device body saddle is immediately distal to the distal-most intersection of the first and second arms.
In at least one envisioned embodiment, the device comprises and implantable medical material for placement in a patient lung along a first and second airways of an airway fork. Specifically, the device comprising a first elongated arm dimensioned to reside along a length of the first airway, a second elongated arm dimensioned to reside along a length of the second airways, and a device body with a proximal and distal end configured to remain at the airway fork, the device body further comprising a proximal vertex connecting the first and second arms. In at least one further envisioned embodiment, at least one arm of the device further comprises a locking mechanism or ridge, said ridge configured to remain proximal to the airway fork. In a further embodiment, the device it is further envisioned that the rotation of the vertex reconfigured the device with said ridge contact the opposite arm, applying a bias along the arms to the lengths of airway sufficient to reduce the volume of the lung associated with the airways.
In some embodiments, each arm 122 may have a diameter 0.5 to 3.0 mm and length of 5 to 50 mm The diameter of the arms may taper in a distal direction of the arms, where the proximal end of the arm 122 is at the saddle 126. The length of the arms 122 may be selected based on the dimensions of the septum 28 and branches into which the lung reduction device is to be implanted. There may be lung reduction devices having arms of different lengths to be placed in a specific pair of branches 25 of lung tissue.
At the time of a lung reduction treatment, the physician may have a set of lung reduction devices of different sizes, diameters and other configurations. The physician may select a lung reduction device based on knowledge of the size of the branches into which the devices are to be implanted and information gained from the images of the branches. Imaging by CT or MRI obtained in advance of the procedure can be used to facilitate the election.
Each lung reduction device may be supplied enveloped in an optional sheath that may be selected by the physician and loaded into a proximal end of the catheter 106. The delivery tool (e.g. rod, grasper or gripper) may abut or grip the proximal end of the stem of the selected lung reduction device by sliding the sheath over the delivery tool 108 of the delivery device. If a sheath is not used, the device can alternatively be loaded directed into the proximal end of the catheter 106 to enter through the working channel 110 or directly in the airway 24.
To reduce tissue damage and inflammation, the distal end of the lung reduction device 120 may be constructed and configured to be atraumatic, specifically at the distal nubs 128 of the device. The nubs 128 of the arms 122 of the lung reduction device 120 may be circular, rounded, spherical, hemispherical or otherwise dimensioned to reduce irritation after prolonged contact and bias again airway 24 walls. In some instances, it may be preferred that beyond the arm 122 and nubs 128, additional or all parts of the lung reduction device 120 are configured to be atraumatic. In the alternative, all or portions of the arms 122 or saddle 126 of the lung reduction device 120 may be configured to achieve and maintain contact with the airway 24 between the arms 122. In another alternative, the nubs 128 of the device may be configured to achieve and maintain the inward tension between the arms 122 of the device 120. In another alternative, the lung reduction device 120 may also be configured to be placed to advantage the user or practitioner in a manner that allows for subsequent removable through reverse and/or similar methods used for delivering and deploying the lung reduction device.
The lung reduction device shown in
The deployment of the lung reduction device 120 follows the steps shown in
In some aspects, the delivery tool 108 (e.g. rod, pusher, grasper or gripper) may be configured to affect the tension between the arms 122 of the lung reduction device 120. Specifically, the delivery tool 108 may actuate a mechanism of the stem 124 or lung reduction device 120 to render the arms 122 inactive, or in a state of reduced tension. In such embodiments, the release of the stem 124 or lung reduction device 120 from the delivery tool 108 would actuate the arms 122 of the lung reduction device 120. In at least one aspect of the device of
Once positioned, the arms 122 are able to exert the compressing force to reduce the volume of the diseased lung tissue 50 between the aims 122 of the lung reduction device 120. In further embodiments where a delivery tool 108 is more complex, such as a grasper or forceps that are used to deploy the device 120, it is envisioned that a rotation, ratchet action or other tool manipulation from the proximal end may be performed to release the stem 124. Once no longer attached or in contact with the delivery tool 108, the device may return to its natural deployed configuration.
The opening at the distal end of the catheter is positioned facing a bifurcation of the airway bifurcation 26 providing positioning of the lung reduction device 120 at the airway bifurcation. One or two diverging guide wires can be retained in the bifurcating airways to assist visualization on the fluoroscopic X-ray imaging device such as a C-Arm fluoroscope. In
The distal and proximal portions of the lung reduction device 120 are configured to remain in contact with the tissue of the airway 24 and therefore should be constructed to be atraumatic. Lung reduction device deployment is completed and the delivery tool 108 is removed from contact with the proximal stem 124 (proximal end) of the lung reduction device 120 (
In a further aspect, the deployment and implantation of a lung reduction device 220 may follow the steps shown in
In a further aspect, a lung reduction device 320, as illustrated by
The deployment of the lung reduction device 320 with a locking tab 318 of
Finally,
As discussed, minimally invasive techniques are one envisioned method of device delivery and may include the use of a bronchoscope to help position and deploy the clip. A bronchoscope 104 is inserted through the mouth, trachea 10 and into the lung airways. A physician maneuvers a distal end of the bronchoscope and may be assisted by viewing an image of the lung airways 24 at the distal end captured with a miniature visual recorder that is held within the bronchoscope. Computed tomography (CT) and fluoroscopy imaging may also be used for imaging and navigation. An airway bifurcation 26 and septum 28 formed between two diverging lung airway may be identified and confirmed as a target for positioning the lung reduction device.
After identification of the selected airway bifurcation 26, the bronchoscope is navigated through branches of the lung airways 24 leading to the bifurcation 26. In addition to any visual recorder or camera which displays an image of the airway directly in front of the distal end of the scope, the tip may also deflect to assist the user in navigating the airways. The images can be used to maneuver the distal end through the trachea and larger sized braches 25 of the lung airways 24. As a result of large size relative to the catheter, the bronchoscope may not always extend to the desired smaller generations of airways with the target location and tissue 50.
To traverse the smaller braches, a catheter, guide wire, or combined system (not shown) is extended from the distal end of the bronchoscope 104 and maneuvered through the increasing smaller branches until the distal end of the delivery device extends to the selected bifurcation. A guide wire 102 may then be passed into a branch adjacent the selected bifurcation. The guide wire 102 can be used to navigate into distal airways 24 (too small for bronchoscope) under fluoroscopic guidance. When used, a catheter 106 travels along the path of guide wire 102 to maneuver the distal end of the catheter to the vicinity of the selected bifurcation. The guide wire 102 may extend through the distal tip portion of the catheter and be housed entirely within the length of the catheter. The guide wire 102 may be retracted after the distal end of the catheter is positioned near the selected bifurcation, or it may serve further use in positioning the device.
It is envisioned in some embodiments that no guide wire 102 is needed to position and deploy the device. In other embodiments, a single or dual-wire system may be used. Guide wire systems may have additional advantages in delivery, which are also described herein Similarly, when advantageous, a sheath or catheter may be used to deliver the device. As shown in
As the lung reduction device 120 is deployed (
While the measure of success of the lung reduction device described herein is determined most reliably on a case-by-case basis, benchmarks (measured or self-report data) such as lung volume, exercise tolerance and metabolic efficiency can be used to gauge the success across a wider patient population. For instance, in at least one instance, the invention may compose novel method of treating emphysema of the lung by reducing the RV of the air trapped in the lung by deploying a lung reduction device at the bifurcation of an airway 24 where the lung reduction device 120 is equipped with at least two arms that are inserted into the branching (i.e. bifurcating or trifurcating) airways and after deployment the lung reduction device exerts compressing force that compresses diseased lung tissue 50 and reduces volume of the lung at least partially restoring the elastic recoil. A measure of RV reduction may be one index to indicate the successful deployment of the device.
In another embodiment, the invention may comprise the novel method of improving exercise tolerance in the patients with emphysema by reducing RV of air trapped in the lung that consists of identifying patients with high RV, such as more than 50% to 250% above predicted value, lung reduction device in the bifurcation 26 of the airway 24 of the patient where the elastic lung reduction device at least partially resides in two bifurcating airways and exerts compressing force on diseased tissue 50 between the branching (e.g. bifurcating) airways 24 thus reducing the lung volume.
In some embodiments, the thoracic cavity, including the lungs and diaphragm, can be imaged to evaluate and/or verify the desired lung characteristics, which may also comprise a shape, curvature, position and orientation of the diaphragm, and localized density or a density distribution map (visualize diseased portions of the lung). The thoracic cavity may be imaged using fluoroscopy, X-rays, CT scanners, PET scanners, and MRI scanners or other imaging devices and modalities. Pretreatment image data may be processed to provide a comparison to those measurements taken during and after the procedure. Patients with radiologic evidence of lung hyperinflation with flat diaphragms on chest X-Rays and areas of severe emphysema intermingled with better preserved lung tissue (heterogeneous emphysema) on CT scans are candidates for lung volume reduction 182. Patients not deemed a candidate may be offered alternative therapeutic interventions 184.
Upon identifying a candidate for lung volume reduction through patient selection 180, a targeted portion of the lung is treated by identifying the airway 186 in close proximity to the targeted portion of the lung. The lung reduction device is deployed 188 compressing one or more portions of disease tissue 50 to provide the desired therapeutic effect. Evaluation of the lung function after the targeted portion of the lung has been compressed is performed to determine the efficacy of the treatment throughout the procedure. A determination of therapy success 189 is made based on the total lung volume reduction and a decrease in symptoms, which may be self-reported in some instances. Additional implants may be delivered and deployed 190 as described above until desired lung function or therapy success 189 is achieved. Upon achievement of the desired lung function, the therapy is concluded 194. The procedure may be aborted 192 or the lung reduction devices may be removed if the therapy is determined to be unsuccessful.
As illustrated by
In certain aspects, the dimensions of the device, including the device body 421 and arms may vary, as needed, to conform to variations in airway dimensions. The dimensions defined by illustration in
The relatively ease of transition between the stages shown in
Another challenge that faces device delivery are the current dimensions needed to accommodate minimally invasive devices and techniques. Generally, a bronchoscope 104 equipped with visualization (e.g. camera 105) and a large working channel 2-3 mm in diameter cannot proceed distally or downstream beyond the 4th generation of airways. A bronchoscope 104 without a large working channel 110 can pass several generations deeper into the lung, but does not have the capabilities of larger scopes Similarly, catheters, sleeves and guide wires can each penetrate deeper into the lung, but face various limitations in each case. In some aspects, it is envisioned that the delivery of the clip may be performed with or without the use of one or more guide wires. However, when used, guide wires or guide wires used as a part of larger delivery system, may be able to overcome the size limitation faced with bronchoscope delivery, and may simultaneously produce several unexpected advantageous.
In at least one embodiment, a single guide wire 102, like the one shown in
In an envisioned embodiment, a lung reduction device (i.e. clip) may be configured, as illustrated in
A grooved, over-wire delivery system may also assist in providing rapid sequential delivery of clips to target areas. For example, a clip device may be configured with elements (e.g. groove, notch or specific shapes, etc.) to help guide clip during the delivery of a first clip while simultaneously positing a second clip to take the position of the first clip upon delivery without need to withdraw and reposition the guidewire.
In
In
While the benefits of single guide wire assisted delivery have been described, it is envisioned in at least one alternative embodiment that dual guide wires may be used to position and deploy a specifically configured airway clip. Such a clip, as shown in
In some instances, it may be advantageous to further reduce the dimensional requirements needed to deliver one or more clips to a target location. By reducing or eliminating the working channel 110, the diameter of a bronchoscope 104 may be greatly reduced while maintaining visualization and navigation ability. Thus, the smaller bronchoscope 104 can advance deeper into the lung.
It is further envisioned that the device body 621 of the device 620 could be configured to allow the clip device to be grasped by a delivery tool 108 to assist in device positioning, deployment or removal. In is envisioned that with a reduced or entirely absent a working channel, the device delivery could be performed by loading the clip or clips to the exterior of the scope, as shown in
In yet another aspect, as seen proximal to the distal region of the device body 621 shown in
In at least one aspect, it is envisioned that a delivery sheath may be used in combination with an over-scope delivery to house the clip until it has been correctly positioned. In another aspect, a catheter 106 may be advanced alongside a bronchoscope 104 to provide a second working channel for purposes including wire or device delivery.
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. Each embodiments described and illustrated in the figures may be shown with repeat-reference numerals, with the understanding that each embodiment can be viewed independent from each other. 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 that 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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201610962125.1 | Nov 2016 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2017/042048 | 7/14/2017 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62362330 | Jul 2016 | US |
