Patent Application
20080295829
The present invention relates to methods and devices for treating diseased lungs including lungs damaged by chronic obstructive pulmonary disease and emphysema.
Chronic obstructive pulmonary disease is a persistent obstruction of the airways caused by chronic bronchitis and pulmonary emphysema. In the United States alone, approximately fourteen million people suffer from some form of chronic obstructive pulmonary disease and it is in the top ten leading causes of death.
Air enters the mammalian body through the nostrils and flows into the nasal cavities. As the air passes through the nostrils and nasal cavities, it is filtered, moistened and raised or lowered to approximately body temperature. The back of the nasal cavities is continuous with the pharynx (throat region); therefore, air may reach the pharynx from the nasal cavities or from the mouth. Accordingly, if equipped, the mammal may breathe through its nose or mouth. Generally air from the mouth is not as filtered or temperature regulated as air from the nostrils. The air in the pharynx flows from an opening in the floor of the pharynx and into the larynx (voice box). The epiglottis automatically closes off the larynx during swallowing so that solids and/or liquids enter the esophagus rather than the lower air passageways or airways. From the larynx, the air passes into the trachea, which divides into two branches, referred to as the bronchi. The bronchi are connected to the lungs.
The lungs are large, paired, spongy, elastic organs, which are positioned in the thoracic cavity. The lungs are in contact with the walls of the thoracic cavity. In humans, the right lung comprises three lobes and the left lung comprises two lobes. Lungs are paired in all mammals, but the number of lobes or sections of lungs varies from mammal to mammal. Healthy lungs, as discussed below, have a tremendous surface area for gas/air exchange. Both the left and right lung is covered with a pleural membrane. Essentially, the pleural membrane around each lung forms a continuous sac that encloses the lung. A pleural membrane also forms a lining for the thoracic cavity. The space between the pleural membrane forming the lining of the thoracic cavity and the pleural membranes enclosing the lungs is referred to as the pleural cavity. The pleural cavity comprises a film of fluid that serves as a lubricant between the lungs and the chest wall.
In the lungs, the bronchi branch into a multiplicity of smaller vessels referred to as bronchioles. Typically, there are more than one million bronchioles in each lung. Each bronchiole ends in a cluster of extremely small air sacs referred to as alveoli. An extremely thin, single layer of epithelial cells lining each alveolus wall and an extremely thin, single layer of epithelial cells lining the capillary walls separate the air/gas in the alveolus from the blood. Oxygen molecules in higher concentration pass by simple diffusion through the two thin layers from the alveoli into the blood in the pulmonary capillaries. Simultaneously, carbon dioxide molecules in higher concentration pass by simple diffusion through the two thin layers from the blood in the pulmonary capillaries into the alveoli.
Breathing is a mechanical process involving inspiration and expiration. The thoracic cavity is normally a closed system and air cannot enter or leave the lungs except through the trachea. If the chest wall is somehow compromised and air/gas enters the pleural cavity, the lungs will typically collapse. When the volume of the thoracic cavity is increased by the contraction of the diaphragm, the volume of the lungs is also increased. As the volume of the lungs increase, the pressure of the air in the lungs falls slightly below the pressure of the air external to the body (ambient air pressure). Accordingly, as a result of this slight pressure differential, external or ambient air flows through the respiratory passageways described above and fills the lungs until the pressure equalizes. This process is inspiration. When the diaphragm is relaxed, the volume of the thoracic cavity decreases, which in turn decreases the volume of the lungs. As the volume of the lungs decrease, the pressure of the air in the lungs rises slightly above the pressure of the air external to the body. Accordingly, as a result of this slight pressure differential, the air in the alveoli is expelled through the respiratory passageways until the pressure equalizes. This process is expiration.
Chronic obstructive pulmonary disease is a persistent obstruction of the airways caused by chronic bronchitis and pulmonary emphysema. Chronic bronchitis and acute bronchitis share certain similar characteristics; however, they are distinct diseases. Both chronic and acute bronchitis involve inflammation and constriction of the bronchial tubes and the bronchioles; however, acute bronchitis is generally associated with a viral and/or bacterial infection and its duration is typically much shorter than chronic bronchitis.
In chronic bronchitis, the bronchial tubes secrete too much mucus as part of the body's defensive mechanisms to inhaled foreign substances. Mucus membranes comprising ciliated cells (hair like structures) line the trachea and bronchi. The ciliated cells or cilia continuously push or sweep the mucus secreted from the mucus membranes in a direction away from the lungs and into the pharynx, where it is periodically swallowed. This sweeping action of the cilia functions to keep foreign matter from reaching the lungs. Foreign matter that is not filtered by the nose and larynx, as described above, becomes trapped in the mucus and is propelled by the cilia into the pharynx. When too much mucus is secreted, the ciliated cells may become damaged, leading to a decrease in the efficiency of the cilia to sweep the bronchial tubes and trachea of the mucus containing the foreign matter. This in turn causes the bronchioles to become constricted and inflamed and the individual becomes short of breath. In addition, the individual will develop a chronic cough as a means of attempting to clear the airways of excess mucus.
Individuals who suffer from chronic bronchitis may develop pulmonary emphysema. Pulmonary emphysema may be caused by a number of factors, including chronic bronchitis, long term exposure to inhaled irritants, e.g. air pollution, which damage the cilia, enzyme deficiencies and other pathological conditions. Pulmonary emphysema is a disease in which the alveoli walls, which are normally fairly rigid structures, are destroyed. The destruction of the alveoli walls is irreversible. In pulmonary emphysema, the alveoli of the lungs lose their elasticity, and eventually the walls between adjacent alveoli are destroyed. Accordingly, as more and more alveoli walls are lost, the air exchange (oxygen and carbon dioxide) surface area of the lungs is reduced until air exchange becomes seriously impaired.
Mucus hyper-secretion and dynamic airway compression are mechanisms of airflow limitation in chronic obstructive pulmonary disease. Mucus hyper-secretion is described above with respect to bronchitis. Dynamic airway compression results from the loss of tethering forces exerted on the airway due to the reduction in lung tissue elasticity. In other words, the breakdown of lung tissue leads to the reduced ability of the lungs to recoil and the loss of radial support of the airways. Consequently, the loss of elastic recoil of the lung tissue contributes to the inability of individuals to exhale completely. The loss of radial support of the airways also allows a collapsing phenomenon to occur during the expiratory phase of breathing. This collapsing phenomenon also intensifies the inability for individuals to exhale completely. As the inability to exhale completely increases, residual volume in the lungs also increases. This then causes the lung to establish in a hyperinflated state. The individual develops dyspnea in which the individual can only take short shallow breaths. Essentially, air is not effectively expelled and stale air accumulates in the lungs. Once the stale air accumulates in the lungs, the individual is deprived of oxygen.
Another aspect of an emphysematous lung is that the communicating flow of air between neighboring air sacs is much more prevalent as compared to healthy lungs. This phenomenon is known as collateral ventilation. However, since air cannot be expelled from the native airways due to the loss of tissue elastic recoil and radial support of the airways (dynamic collapse during exhalation), the increase in collateral ventilation does not significantly assist an individual in breathing.
There is no cure for pulmonary emphysema, only various treatments, including exercise, drug therapy, such as bronchodilating agents, lung volume reduction surgery and long term oxygen therapy. Long term oxygen therapy is widely accepted as the standard treatment for hypoxia caused by chronic obstructive pulmonary disease. Typically, oxygen therapy is prescribed using a nasal cannula. There are disadvantages associated with using the nasal cannula. Transtracheal oxygen therapy has become a viable alternative to long term oxygen therapy. Transtracheal oxygen therapy delivers oxygen directly to the lungs using a catheter that is placed through and down the trachea. Bronchodilating drugs only work on a percentage of patients with chronic obstructive pulmonary disease and generally only provide short-term relief. Oxygen therapy is impractical for the reasons described above, and lung volume reduction surgery is an extremely traumatic procedure that involves removing part of the lung. The long term benefits of lung volume reduction surgery are not fully known.
Accordingly, there exists a need for removing trapped gases from a diseased lung or lungs.
The present invention relates to a device for treating diseased lungs, and more particularly, to a bridging element for securing an implantable device that accesses the lung or lungs of a patient through the intercostal space.
The present invention overcomes the limitations in treating diseases associated with chronic obstructive pulmonary disorders, such as emphysema and chronic bronchitis, as described above. A long term oxygen therapy system may be utilized to effectively treat hypoxia caused by chronic obstructive pulmonary disease. A collateral ventilation bypass trap system may be utilized to take advantage of the above-described collateral ventilation phenomenon to increase the expiratory flow from a diseased lung or lungs, thereby treating another aspect of chronic obstructive pulmonary disease. Various methods may be utilized to determine the location or locations of the diseased tissue, for example, computerized axial tomography or CAT scans, magnetic resonance imaging or MRI, positron emission tomograph or PET, and/or standard X-ray imaging. Essentially, the most collaterally ventilated area of the lung or lungs is determined utilizing the scanning techniques described above. Once this area or areas are located, a conduit or conduits are positioned in a passage or passages that access the outer pleural layer of the diseased lung or lungs. The conduit or conduits utilize the collateral ventilation of the lung or lungs and allow the entrapped air to bypass the native airways and be expelled to a containment system outside of the body.
In order for the system to be effective, the components of the system are preferably sealed to the lung. Accordingly, methods and devices to create a chemically and/or mechanically localized pleurodesis of the present invention may be utilized to provide the seals required for effective sealing of the components of the long term oxygen therapy system and the collateral ventilation bypass trap system as well as other devices requiring pleurodesis.
In accordance with one aspect, the present invention is directed to an implantable medical device. The medical device comprising a bridging element configured for attachment between one or more adjacent ribs in a patient and one or more fittings operatively associated with the bridging element. The one or more fittings being configured to receive and secure devices connected to a lung of a patient.
According to one aspect, the present invention is directed to a bridging element for holding and securing a conduit or other medical device implanted in a patient's lung. The bridging element spans the intercostal space through which the devices described herein pass. Accordingly, the bridging element alleviates some of the potential discomfort associated with the chronic placement of a device in the intercostal space.
According to another aspect, the present invention is directed to a bridging element utilized to hold and secure a device passing between the ribs of a patient and into their lung. The bridging element includes a hole or other fitting to secure the device positioned in the lung.
The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings.
A long term oxygen therapy system and method may be utilized to deliver oxygen directly into the lung tissue in order to optimize oxygen transfer efficiency in the lungs. In other words, improved efficiency may be achieved if oxygen were to be delivered directly into the alveolar tissue in the lungs. In emphysema, alveoli walls are destroyed, thereby causing a decrease in air exchange surface area. As more alveoli walls are destroyed, collateral ventilation resistance is lowered. Accordingly, if it can be determined where collateral ventilation is occurring, then the diseased lung tissue may be isolated and the oxygen delivered to this precise location or locations. Various methods may be utilized to determine the diseased tissue locations, for example, computerized axial tomography or CAT scans, magnetic resonance imaging or MRI, positron emission tomograph or PET, and/or standard X-ray imaging. Once the diseased tissue is located, pressurized oxygen may be directly delivered to these diseased areas and more effectively and efficiently forced into the lung tissue for air exchange.
Once the location or locations of the diseased tissue are located, anastomotic openings are made in the thoracic cavity and lung or lungs and one or more oxygen carrying conduits are positioned and sealed therein. The one or more oxygen carrying conduits are connected to an oxygen source which supplies oxygen under elevated pressure directly to the diseased portion or portions of the lung or lungs. The pressurized oxygen essentially displaces the accumulated air and is thus more easily absorbed by the alveoli tissue. In addition, the long term oxygen therapy system may be configured in such a way as to provide collateral ventilation bypass in addition to direct oxygen therapy. In this configuration, an additional conduit may be connected between the main conduit and the individual's trachea with the appropriate valve arrangement. In this configuration, stale air may be removed through the trachea when the individual exhales since the trachea is directly linked with the diseased site or sites in the lung via the conduits. The long term oxygen therapy system improves oxygen transfer efficiency in the lungs thereby reducing oxygen supply requirements, which in turn reduces the patient's medical costs. The system also allows for improved self-image, improved mobility, and greater exercise capability and is easily maintained.
The exemplary system 100 described above may be modified in a number of ways, including the use of an in-line filter. In this exemplary embodiment, both oxygen and air may flow through the system. In other words, during inhalation, oxygen is delivered to the lungs through the oxygen carrying conduit 104 and during exhalation, air from the lungs flow through the oxygen carrying conduit 104. The in-line filter would trap mucus and other contaminants, thereby preventing a blockage in the oxygen source 102. In this exemplary embodiment, no valve 106 would be utilized. The flow of oxygen into the lungs and the flow of air from the lungs is based on pressure differentials.
In order for the exemplary long term oxygen therapy system 100 to function, an air-tight seal is preferably maintained where the oxygen carrying conduit 104 passes through the thoracic cavity and lung. This seal is maintained in order to sustain the inflation/functionality of the lungs. If the seal is breached, air can enter the cavity and cause the lungs to collapse as described above.
A method to create this seal comprises forming adhesions between the visceral pleura of the lung and the inner wall of the thoracic cavity. This may be achieved using either chemical methods, including irritants such as Doxycycline and/or Bleomycin, surgical methods, including pleurectomy or horoscope talc pleurodesis, or radiotherapy methods, including radioactive gold or external radiation. All of these methods are known in the relevant art for creating pleurodesis. With a seal created at the site for the ventilation bypass, an intervention may be safely performed without the danger of creating a pneumothorax of the lung.
Similarly to ostomy pouches or bags, the oxygen carrying conduit 104 may be sealed to the skin at the site of the ventilation bypass. In one exemplary embodiment, illustrated in
The above-described long term oxygen therapy system may be utilized to effectively treat hypoxia caused by chronic obstructive pulmonary disease; however, other means may be desirable to treat other aspects of the disease. A collateral ventilation bypass trap system utilizes the above-described collateral ventilation phenomenon to increase the expiratory flow from a diseased lung or lungs, thereby treating another aspect of chronic obstructive pulmonary disease. Essentially, the most collaterally ventilated area of the lung or lungs is determined utilizing the scanning techniques described above. Once this area or areas are located, a conduit or conduits are positioned in a passage or passages that access the outer pleural layer of the diseased lung or lungs. The conduit or conduits utilize the collateral ventilation of the lung or lungs and allows the entrapped air to bypass the native airways and be expelled to a containment system outside of the body.
If an individual has difficulty exhaling and requires additional oxygen, collateral ventilation bypass may be combined with direct oxygen therapy.
In this exemplary embodiment, as shown in
The trap 702 may comprise any suitable device for collecting discharge from the individual's lung or lungs 708. Essentially, the trap 702 is simply a containment vessel for temporarily storing discharge from the lungs, for example, mucous and other fluids that may accumulate in the lungs. The trap 702 may comprise any suitable shape and may be formed from any suitable metallic or non-metallic materials. Preferably, the trap 702 should be formed from a lightweight, non-corrosive material. In addition, the trap 702 should be designed in such a manner as to allow for effective and efficient cleaning. In one exemplary embodiment, the trap 702 may comprise disposable liners that may be removed when the trap 702 is full. The trap 702 may be formed from a transparent material or comprise an indicator window so that it may be easily determined when the trap 702 should be emptied or cleaned. A lightweight trap 702 increases the patient's mobility.
The filter/one-way valve 706 may be attached to the trap 702 by any suitable means, including threaded fittings or compression type fittings commonly utilized in compressor connections. The filter/one-way valve 706 serves a number of functions. The filter/one-way valve 706 allows the air from the individual's lung or lungs 708 to exit the trap 702 while maintaining the fluid discharge and solid particulate matter in the trap 702. This filter/one-way valve 706 would essentially maintain the pressure in the trap 702 below that of the pressure inside the individual's lung or lungs 708 so that the flow of air from the lungs 708 to the trap 702 is maintained in this one direction. The filter portion of the filter/one-way valve 706 may be designed to capture particulate matter of a particular size which is suspended in the air, but allows the clean air to pass therethrough and be vented to the ambient environment. The filter portion may also be designed in such a manner as to reduce the moisture content of the exhaled air.
The air carrying conduit 704 connects the trap 702 to the lung or lungs 708 of the patient through the filter/one-way valve 706. The air carrying conduit 704 may comprise any suitable biocompatible tubing having a resistance to the gases contained in air. The air carrying conduit 704 comprises tubing having an inside diameter in the range from about 1/16 inch to about ½ inch, and more preferably from about ⅛ inch to about ¼ inch. The filter/one-way valve 706 may comprise any suitable valve which allows air to flow from the lung or lungs 708 through the air carrying conduit 704, but not from the trap 702 back to the lungs 708. For example, a simple check valve may be utilized. The air carrying conduit 704 may be connected to the filter/one-way valve 706 by any suitable means. Preferably, a quick release mechanism is utilized so that the trap may be easily removed for maintenance.
As illustrated in
The air carrying conduit 704 is preferably able to withstand and resist collapsing once in place. Since air will travel through the conduit 704, if the conduit is crushed and unable to recover, the effectiveness of the system is diminished. Accordingly, a crush recoverable material may be incorporated into the air carrying conduit 704 in order to make it crush recoverable. Any number of suitable materials may be utilized. For example, Nitinol incorporated into the conduit 704 will give the conduit collapse resistance and collapse recovery properties.
Expandable features at the end of the conduit 704 may be used to aid in maintaining contact and sealing the conduit 704 to the lung pleura. Nitinol incorporated into the conduit 704 will provide the ability to deliver the conduit 704 in a compressed state and then deployed in an expanded state to secure it in place. Shoulders at the end of the conduit may also provide a mechanical stop for insertion and an area for an adhesive/sealant to join as described in detail subsequently.
In order for the exemplary collateral ventilation bypass trap system 700 to function, an air-tight seal is preferably maintained where the air carrying conduit 704 passes through the thoracic cavity and lungs 708. A sealed joint 705 is provided at the end of conduit 704. This seal is maintained in order to sustain the inflation/functionality of the lungs. If the seal is breached, air can enter the cavity and cause the lungs to collapse. One exemplary method for creating the seal comprises forming adhesions between the visceral pleura of the lung and the inner wall of the thoracic cavity. This may be achieved using either chemical methods, including irritants such as Doxycycline and/or Bleomycin, surgical methods, including pleurectomy or thorascopic talc pleurodesis, or radiotherapy methods, including radioactive gold or external radiation. All of these methods are known in the relevant art for creating pleurodesis. In another alternate exemplary embodiment, a sealed joint between the air carrying conduit 704 and the outer pleural layer includes using various glues to help with the adhesion/sealing of the air carrying conduit 704. Currently, Focal Inc. markets a sealant available under the trade name FOCAL/SEAL-L which is indicated for use on a lung for sealing purposes. Focal/Seal-L is activated by light in order to cure the sealant. Another seal available under the trade name THOREX, which is manufactured by Surgical Sealants Inc., is currently conducting a clinical trial for lung sealing indications. Thorex is a two-part sealant that has a set curing time after the two parts are mixed.
The creation of the opening in the chest cavity may be accomplished in a number of ways. For example, the procedure may be accomplished using an open chest procedure, sternotomy or thoracotomy. Alternately, the procedure may be accomplished using a laparoscopic technique, which is less invasive. Regardless of the procedure utilized, the seal should be established while the lung is at least partially inflated in order to maintain a solid adhesive surface. The opening may then be made after the joint has been adequately created between the conduit component and the lung pleural surface. The opening should be adequate in cross-sectional area in order to provide sufficient decompression of the hyperinflated lung. This opening, as stated above, may be created using a number of different techniques such as cutting, piercing, dilating, blunt dissection, radio frequency energy, ultrasonic energy, microwave energy, or cryoblative energy.
The air carrying conduit 704 may be sealed to the skin at the site by any of the means and methods described above with respect to the oxygen carrying conduit 704 and illustrated in
In operation, when an individual exhales, the pressure in the lungs is greater than the pressure in the trap 702. Accordingly, the air in the highly collateralized areas of the lung will travel through the air carrying conduit 704 to the trap 702. This operation will allow the individual to more easily and completely exhale.
In the above-described exemplary apparatus and procedure for increasing expiratory flow from a diseased lung using the phenomenon of collateral ventilation, there will be an optimal location to penetrate the outer pleura of the lung to access the most collaterally ventilated area or areas of the lung. As described above, there are a variety of techniques to locate the most collaterally ventilated area or areas of the lungs. Since a device or component of the apparatus functions to allow the air entrapped in the lung to bypass the native airways and be expelled outside of the body, it is particularly advantageous to provide an air-tight seal of the parietal (thoracic wall) and visceral (lung) pleurae. If a proper air-tight seal is not created between the device, parietal and visceral pleurae, then a pneumothorax (collapsed lung) may occur. Essentially, in any circumstance where the lung is punctured and a device inserted, an air-tight seal should preferably be maintained.
One way to achieve an air-tight seal is through pleurodesis, i.e. an obliteration of the pleural space. There are a number of pleurodesis methods, including chemical, surgical and radiological. In chemical pleurodesis, an agent such as tetracycline, doxycycline, bleomycin or nitrogen mustard may be utilized. In surgical pleurodesis, a pleurectomy or a thorascopic talc procedure may be performed. In radiological procedures, radioactive gold or external radiation may be utilized. In the present invention, chemical pleurodesis is utilized. Exemplary methods for creating the seal comprises forming adhesions between the visceral pleura of the lung and the inner wall of the thoracic cavity using chemical methods, including irritants such as Doxycycline and/or Bleomycin, surgical methods, including pleurectomy or thorascopic talc pleurodesis. In another alternate exemplary embodiment, a sealed joint between the air carrying conduit 704 and the outer pleural layer includes using various glues to help with the adhesion/sealing of the air carrying conduit 704. Currently, Focal Inc. markets a sealant available under the trade name FOCAL/SEAL-L which is indicated for use on a lung for sealing purposes. Focal/Seal-L is activated by light in order to cure the sealant. Another seal available under the trade name THOREX, which is manufactured by Surgical Sealants Inc., is currently conducting a clinical trial for lung sealing indications. Thorex is a two-part sealant that has a set curing time after the two parts are mixed.
Exemplary devices and methods for delivering a chemical(s) or agent(s) in a localized manner for ensuring a proper air-tight seal of the above-described apparatus is described below. The chemical(s), agent(s) and/or compound(s) are used to create a pleurodesis between the parietal and visceral pleura so that a component of the apparatus may penetrate through the particular area and not result in a pneumothorax. There are a number of chemical(s), agent(s) and/or compound(s) that may be utilized to create a pleurodesis in the pleural space. The chemical(s), agent(s) and/or compound(s) include talc, tetracycline, doxycycline, bleomycin and minocycline.
In one exemplary embodiment, a modified drug delivery catheter may be utilized to deliver chemical(s), agent(s) and/or compound(s) to a localized area for creating a pleurodesis in that area. In this exemplary embodiment, the pleurodesis is formed and then the conduit 704, as illustrated in
As illustrated in
The distal end or tip 802 of the catheter 800 should preferably maintain its desired size, shape and/or configuration once deployed in the pleural space. This may be accomplished in a number of ways. For example, the material forming the distal end 802 of the catheter 800 may be selected such that it has a certain degree of flexibility for insertion of the catheter 800 and a certain degree of shape memory such that it resumes its original or programmed shape once deployed. Any number of biocompatible polymers with these properties may be utilized. In an alternate embodiment, another material may be utilized. For example, a metallic material having shape memory characteristics may be integrated into the distal end 802 of the catheter 800. This metallic material may include Nitinol or stainless steel. In addition, the metallic material may be radiopaque or comprise radiopaque markers. By having a radiopaque material or radiopaque markers, the catheter 800 may be viewed under x-ray fluoroscopy and aid in determining when the catheter 800 is at the location of the highest collateral ventilation.
In another alternate exemplary embodiment, a local drug delivery device may be utilized to deliver the pleurodesis chemical(s), agent(s) and/or compound(s). In this exemplary embodiment, the pleurodesis is formed and then the conduit 704, as illustrated in
Any of the above-described chemical(s), agent(s) and/or compound(s) may be affixed to the medical device. The chemical(s), agent(s) and/or compound(s) may be affixed to the medical device in any suitable manner. For example, the chemical(s), agent(s) and/or compound(s) may be coated on the device utilizing any number of well known techniques including, spin coating, spraying or dipping, they may be incorporated into a polymeric matrix that is affixed to the surface of the medical device, they may be impregnated into the outer surface of the medical device, they may be incorporated into holes or chambers in the medical device, they may be coated onto the surface of the medical device and then coated with a polymeric layer that acts as a diffusion barrier for controlled release of the chemical(s), agent(s) and/or compound(s), they may be incorporated directly into the material forming the medical device, or any combination of the above-described techniques. In another alternate embodiment, the medical device may be formed from a biodegradable material which elutes the chemical(s), agent(s) and/or compound(s) as the device degrades.
The implantable medical device may comprise any suitable size, shape and/or configuration, and may be formed using any suitable biocompatible material.
As described in the previous exemplary embodiment, the disk 900 may comprise a radiopaque marker or be formed from a radiopaque material. The radiopaque marker or material allows the disk 900 to be seen under fluoroscopy and then positioned accurately.
In yet another alternate exemplary embodiment, the fluid characteristics of the chemical(s), agent(s) and/or compound(s) may be altered. For example, the chemical(s), agent(s) and/or compound(s) may be made more viscous. With a more viscous chemical agent and/or compound, there would be less chance of the chemical, agent and/or compound moving from the desired location in the pleural space. The chemical(s), agent(s) and/or compound(s) may also comprise radiopaque constituents. Making the chemical(s), agent(s) and/or compounds radiopaque would allow the confirmation of the location of the chemical(s), agent(s) and/or compound(s) with regard to the optimal location of collateral ventilation. The chemical(s), agent(s) and/or compound(s) as modified above may be utilized in conjunction with standard chemical pleurodesis devices and processes or in conjunction with the exemplary embodiments set forth above.
In an alternate exemplary embodiment, an implantable structure in combination with a chemical agent and/or a therapeutic agent may be utilized to create a localized area where the visceral and parietal pleura of the lung are fused together. In this exemplary embodiment, a localized pleurodesis may be created utilizing either or both a mechanical component and a chemical component. The purpose of the chemical component is to provide an acute adhesion between the parietal and visceral pleura, while the mechanical component is utilized to provide a chronic adhesion. In other words, the acute adhesion provided by the chemical adhesive would provide enough stability at the implant location on the lung to allow for the mechanical component to create a chronic adhesion. The combination of a chemical adhesive with a tissue growth promoting material in a specific area of the lung would promote a well-controlled localized pleurodesis reaction.
Radiological markers may be incorporated into the device 1000 thereby increasing its radiopacity under fluoroscopy. Essentially, this would ensure that in follow-up examinations, the exact location of where the localized pleurodesis has grown would be easy to find. These markers may be incorporated into the device 1000 in any number of suitable ways. For example, as shown in
The delivery of the device 1000 may be approached utilizing any number of acceptable procedures. In one exemplary embodiment, a thoracotomy procedure to open the thoracic cavity may be performed, and the device 1000 placed directly in the location. In another exemplary embodiment, a minimally invasive approach using a cannula or such like device may be utilized to percutaneously access the thoracic cavity. The device 1000 could then be entirely delivered via a delivery system through the cannula or sheath.
Current pleurodesis procedures look to create adhesion between the entire lung and the thoracic wall, effectively sealing off any thoracic cavity spaces. The device of the present invention allows for a small controlled local pleurodesis to form, thereby reducing potentially painful side effects and minimize pleural adhesions for subsequent thoracic interventions. Additionally, due to the dynamic nature between the lung and thoracic wall, it may be difficult to create a chronic local pleurodesis without the help of a clinical adhesive to provide acute stability to the location of intent.
For any of the above-described devices that require access to a patient's lung or lungs via surgically attaching a conduit to the lung or lungs and not through a native airway, the visceral pleura must be properly attached to the conduit in order to properly seal around the conduit. A technique that may be utilized is to gather and attach the visceral pleura around the conduit using a purse-string suture or similar technique. This technique, however, requires the handling of the pleura in order to provide a counterforce on the pleura as the conduit is being positioned in the lung. In addition, what makes this technique more difficult is as soon as an access is made through the pleura for the conduit, the lung will immediately leak air and collapse to a smaller size. Therefore, providing a counterforce to insert a conduit or other device described herein through the access in the lung becomes even more vital.
The visceral pleura of the lung are thin and somewhat fragile. Manipulation of the pleura using surgical instruments such as forceps or hemostats may create a break in the pleura. It is often difficult to seal the leak that will follow and the leak will typically result in a pneumothorax or a collapsed lung. In an emphysematous lung where the patient is already compromised with the inability to breath, a pneumothorax may potentially lead to serious complications, including death.
Although there are devices that resect lung tissue and help seal it thereafter, there are currently no devices that enter the lung through the visceral pleura. Lung resection and buttressing devices do not need to rely on stabilization and counterforce. Accordingly, the present invention is directed to a device that would provide the ability to insert a conduit or other device in the lung with a significantly decreased chance of injuring the lung if conventional surgical tools are utilized. Essentially, if a device could stabilize the visceral pleura and provide the counterforce without damaging the pleura, the procedure of inserting the device in the lung could become easier, faster and less conducive to injuring the pleura.
In accordance with one exemplary embodiment, a vacuum assist device 1102 may be utilized to hold the pleura while a conduit or other device is being positioned in the lung. Referring to
As illustrated in
Once the vacuum assist device 1102 is inserted and placed into contact with the visceral pleura 1101, the vacuum is started and draws and holds the visceral pleura 1101 in place while the conduit 1204 or other device is inserted through the envelope 1106. The vacuum assist device 1102 maintains the counter-pressure for insertion and sealing without damaging the lung tissue. When the seal is created, the vacuum is cut off and the device 1102 is removed.
The vacuum pressure or negative pressure may be created in a variety of ways. For example, surgical sites are typically equipped with vacuum devices that may be regulated to draw a negative pressure in the desired range. A simple pressure regulator or vacuum regulator may be connected between two vacuum sources and the device 1102 by any suitable means. In alternate exemplary embodiments, the device 1102 may comprise a vacuum pump and regulator. The vacuum pump may use hospital power or be a self-contained battery power unit.
As described above, once a device such as a conduit 1204 is inserted into the lung, the device must be sealed to the lung tissue. Also as described above is the purse-string suture that may be utilized to gather and attach the visceral pleura 1101 around the conduit 1204 or other device to create the seal. While this technique and other similar techniques may be utilized to create a seal, when the suture is pushed through the visceral pleura 1101 and around the conduit 1204, it will inevitably leave small holes or tears through the pleura which may eventually lead to leaks. Accordingly, it would be advantageous to seal the visceral pleura 1101 around the conduit 1204 without having to make any holes or tears through or in the visceral pleura 1101. If the visceral pleura 1101 were to be gathered around the conduit or other device, it would provide the accessibility to use a ring-type device to secure the gathered pleura around the conduit or other medical device.
Referring to
In an alternate exemplary embodiment, one or more agents may be affixed to the ring 1300. The one or more agents may be directly affixed to the surface of the ring 1300, incorporated into a polymeric vehicle and then affixed to the surface of the ring 1300, incorporated into channels or holes in the ring 1300 or incorporated into the bulk material forming the ring 1300. The one or more agents may include chemicals to promote the pleurodesis reaction between the parietal pleura (inner thoracic wall) and the visceral pleura (lung). The pleurodesis is a key component to the chronic success of the procedure. The pleurodesis reaction will allow for the anastomosis to chronically exist without the danger of pneumothorax.
In accordance with another exemplary embodiment, a pulmonary visceral pleura anastomosis reinforcement device may be utilized to create a strong and air tight seal around a conduit of other device positioned in the lung through a non-native airway. As described above, when a suture is passed through the visceral pleura and around the conduit, it will inevitably leave small holes or tears through the pleura which may lead to leaks. However, the advantage of the purse-string suture is the ability for the conduit or other device to be removed from the anastomosis even after the suture has been secured. The pulmonary visceral pleura anastomosis reinforcement device may be positioned around the conduit or other device prior to making the purse-string suture thereby reducing the likelihood of a suture hole or tear leading to leaks and potentially a pneumothorax.
Referring to
The pulmonary visceral pleura anastomosis reinforcement device 1400 may be a removable device or a permanent implant. The reinforcement device 1400 may be sutured in place, stapled into place, affixed in place with a tissue adhesive or any other suitable means. In addition, the reinforcement device may be combined with a tissue growth factor to promote endothelialization.
The pulmonary visceral pleura anastomosis reinforcement device 1400 may be fabricated from any number of biocompatible materials, including metals, metal alloys and polymers. The material may be biodegradable, for example, polyglycolic acid or non-biodegradable, for example Teflon®. In addition, the material may comprise animal tissue. Currently, materials exist that prevent leaks from occurring where tissue is resected from the lungs. A number of various materials, including Teflon® are currently being utilized. However, in the present invention, the material is formed into a structure for the acute reinforcement around a bypass anastomosis to prevent any leakage.
One or more agents may be affixed to the reinforcement device 1400. The one or more agents may be directly affixed to the surface of the reinforcement device 1400, incorporated into a polymeric vehicle and then affixed to the surface of the reinforcement device 1400, incorporated into channels or holes in the reinforcement device 1400. The one or more agents may include chemicals to promote the pleurodesis reaction between the parietal pleura (inner thoracic wall) and the visceral pleura (lung). The pleurodesis is a key component to the chromic success of the procedure. The pleurodesis reaction will allow for the anastomosis to chronically exist without the danger of pneumothorax.
The above-described devices are utilized to treat the symptoms of chronic obstructive pulmonary disease by applying the theory of collateral ventilation. The devices would provide trapped air in the lung to escape through an alternate pathway through the pleura of the lung. In order for these devices to be effective, the conduits should preferably remain patent throughout the lifetime of the implant. Because the body reacts to implants by building tissue barriers around the device, the patency of the implant may come into question. Accordingly, the present invention relates to a device that allows all previously described devices to remain patent once implanted into the lung parenchyma. Tissue growth at the tip of the conduit or other device is hindered or inhibited mechanically or chemically. By doing this, one could ensure that the lumen of the implant remains patent thereby allowing air from the lung to move freely through the device.
Exemplary mechanical embodiments of the present invention may include features attached to or part of the implanted device or independent devices used as accompaniments to the implant, for example, introduced periodically utilizing interventional techniques. For example, as illustrated in
In an exemplary stand-alone embodiment, as illustrated in
In an alternate exemplary embodiment a modified balloon catheter 1702, as illustrated in
Each of these independent devices may be used periodically on a consistent basis for as long as the implant remains in the body.
Tissue growth hindrance or inhibition may also be achieved through the application of certain drugs. For example, as illustrated in
In yet another alternate exemplary embodiment, a drug or agent may be injected locally through the lumen of the device as illustrated in
While exemplary embodiments of the invention have been described with respect to the treatment of tissue in-growth and related complications, it is important to note that the local delivery of drug/drug combinations may be utilized to treat a wide variety of conditions utilizing any number of medical devices, or to enhance the function and/or life of the device. For example, intraocular lenses, placed to restore vision after cataract surgery is often compromised by the formation of a secondary cataract. The latter is often a result of cellular overgrowth on the lens surface and can be potentially minimized by combining a drug or drugs with the device. Other medical devices which often fail due to tissue in-growth or accumulation of proteinaceous material in, on and around the device, such as shunts for hydrocephalus, dialysis grafts, colostomy bag attachment devices, ear drainage tubes, leads for pace makers and implantable defibrillators can also benefit from the device-drug combination approach. Devices which serve to improve the structure and function of tissue or organ may also show benefits when combined with the appropriate agent or agents. For example, improved osteo-integration of orthopedic devices to enhance stabilization of the implanted device could potentially be achieved by combining it with agents such as bone-morphogenic protein. Similarly other surgical devices, sutures, staples, anastomosis devices, vertebral disks, bone pins, suture anchors, hemostatic barriers, clamps, screws, plates, clips, vascular implants, tissue adhesives and sealants, tissue scaffolds, various types of dressings, bone substitutes, intraluminal devices, and vascular supports could also provide enhanced patient benefit using this drug-device combination approach. Perivascular wraps may be particularly advantageous, alone or in combination with other medical devices. The perivascular wraps may supply additional drugs to a treatment site. Essentially, any type of medical device may be coated in some fashion with a drug or drug combination which enhances treatment over use of the singular use of the device or pharmaceutical agent.
In addition to various medical devices, the coatings on these devices may be used to deliver therapeutic and pharmaceutical agents including: anti-proliferative/anti-mitotic agents including natural products such as vinca alkaloids (i.e. vinblastine, vincristine, and vinorelbine), paclitaxel, epidipodophyllotoxins (i.e. etoposide, teniposide), antibiotics (dactinomycin (actinomycin D) daunorubicin, doxorubicin and idarubicin), anthracyclines, mitoxantrone, bleomycins, plicamycin (mithramycin) and mitomycin, enzymes (L-asparaginase which systemically metabolizes L-asparagine and deprives cells which do not have the capacity to synthesize their own asparagine); antiplatelet agents such as G(GP) llb/llla inhibitors and vitronectin receptor antagonists; anti-proliferative/antimitotic alkylating agents such as nitrogen mustards (mechlorethamine, cyclophosphamide and analogs, melphalan, chlorambucil), ethylenimines and methylmelamines (hexamethylmelamine and thiotepa), alkyl sulfonates-busulfan, nirtosoureas (carmustine (BCNU) and analogs, streptozocin), trazenes-dacarbazinine (DTIC); anti-proliferative/antimitotic antimetabolites such as folic acid analogs (methotrexate), pyrimidine analogs (fluorouracil, floxuridine, and cytarabine), purine analogs and related inhibitors (mercaptopurine, thioguanine, pentostatin and 2-chlorodeoxyadenosine {cladribine}); platinum coordination complexes (cisplatin, carboplatin), procarbazine, hydroxyurea, mitotane, aminoglutethimide; hormones (i.e. estrogen); anti-coagulants (heparin, synthetic heparin salts and other inhibitors of thrombin); fibrinolytic agents (such as tissue plasminogen activator, streptokinase and urokinase), aspirin, dipyridamole, ticlopidine, clopidogrel, abciximab; antimigratory; antisecretory (breveldin); anti-inflammatory: such as adrenocortical steroids (cortisol, cortisone, fludrocortisone, prednisone, prednisolone, 6α-methylprednisolone, triamcinolone, betamethasone, and dexamethasone), non-steroidal agents (salicylic acid derivatives i.e. aspirin; para-aminophenol derivatives i.e. acetaminophen; indole and indene acetic acids (indomethacin, sulindac, and etodalac), heteroaryl acetic acids (tolmetin, diclofenac, and ketorolac), arylpropionic acids (ibuprofen and derivatives), anthranilic acids (mefenamic acid, and meclofenamic acid), enolic acids (piroxicam, tenoxicam, phenylbutazone, and oxyphenthatrazone), nabumetone, gold compounds (auranofin, aurothioglucose, gold sodium thiomalate); immunosuppressives: (cyclosporine, tacrolimus (FK-506), sirolimus (rapamycin), azathioprine, mycophenolate mofetil); angiogenic agents: vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF); angiotensin receptor blockers; nitric oxide donors; antisense oligionucleotides and combinations thereof; cell cycle inhibitors, mTOR inhibitors, and growth factor receptor signal transduction kinase inhibitors; retenoids; cyclin/CDK inhibitors; HMG co-enzyme reductase inhibitors (statins); and protease inhibitors.
In accordance with yet another alternate exemplary embodiment, variable parietal/visceral pleural couplings may be utilized for the placement of conduits or other implantable devices into the lung through non-native airways without the need for the creation of a pleurodesis or localized pleurodesis. In addition, the variable parietal/visceral pleural coupling would allow independent motion of the visceral and parietal pleura without compromising pressures in the thoracic cavity.
Developing a localized fibrotic adhesion between the lung and the inner thoracic wall may be difficult due to the dynamic movement between the two surfaces. Additionally, a small localized area may create a stress concentration area that would lead to a tear in the lung pleura that may potentially cause a pneumothorax. Finally, the adhesion of the surface of the lung may prevent the lung from being fully emptied during exhalation. The present invention overcomes these potential difficulties.
Referring now to
In the long term oxygen therapy systems illustrated in
In one exemplary embodiment, rather than positioning a conduit between the ribs, a hole may be drilled through the rib closest in proximity to the treatment site.
In another exemplary embodiment, a bridge with an opening may be affixed to two ribs. Referring to
A bridging element configured for attachment between one or more adjacent ribs in a patient may have one or more fittings operatively associated with the bridging element. The one or more fittings may be configured to receive and secure devices connected to a lung of a patient. The bridging element includes a hole or other fitting to secure the device positioned in the lung.
A bridging element may be configured for holding and securing a conduit or other medical device implanted in a patient's lung. The bridging element may be utilized to hold and secure a device passing between the ribs of a patient and into their lung. The bridging element spans the intercostal space through which the devices described herein pass. Accordingly, the bridging element alleviates some of the potential discomfort associated with the chronic placement of a device in the intercostal space.
The bridge element 2502 is preferably constructed so as to minimize movement around the conduit 2402 and to secure the conduit 2402 into position without unduly restricting movement of the ribs. It is important that the ribs and rib cage remain flexible for ease of breathing. The bridge element 2502 may also be formed from a flexible material or be constructed to allow for partial movement.
Micro-motion is important so as not to create localized loads on the ribs that are too high or too low because stress has a definite physiological effect on bone. In other words, bones are dynamic elements and they respond to loading or stress. In order to maintain healthy bone, the stress on that bone has to be maintained within a lower and upper limit. If the stress on a bone is too low, osteopenia results. If the stress on a bone is too high, osteopenia results. Accordingly, any design would preferably account for loading conditions and maintain the stress on the ribs within the healthy window or range.
The bridge element 2502 may be affixed to the ribs 2504 utilizing any number of suitable devices. For example, the bridge element 2502 may be glued or cemented to the ribs 2504 utilizing any suitable biocompatible adhesive. Alternately, the bridge element 2502 may be pinned or attached to the ribs 2504 utilizing surgical screws. The bridge element 2502 may be permanently affixed to or temporarily affixed to the ribs. The bridge element 2502 may be clamped between the ribs 2504 or may comprise the clamp itself.
In yet another alternate exemplary embodiment, the ribs 2504 may be joined utilizing a biological material. For example, a bone cement may be utilized to fill the space between adjacent ribs. The bone cement may be utilized with other materials to insure that the ribs are not loaded so that osteopenia occurs. Bone cements and artificial tissues are known in the art.
The bridge element may be clamped between the ribs or may comprise the clamp itself. For example, as illustrated in
Although shown and described in what is believed to be the most practical and preferred embodiments, it is apparent that departures from specific designs and methods described and shown will suggest themselves to those skilled in the art and may be used without departing from the spirit and scope of the invention. The present invention is not restricted to the particular constructions described and illustrated, but should be constructed to cohere with all modifications that may fall within the scope of the appended claims.
| Number | Date | Country | |
|---|---|---|---|
| 60940702 | May 2007 | US |
