The present invention is generally directed to a device, system, and method for treating Chronic Obstructive Pulmonary Disease (COPD). The present invention is more particularly directed to providing an intra-bronchial obstruction that controls biological interaction of the device with the patient.
COPD has become a major cause of morbidity and mortality in the United States over the last three decades. COPD is characterized by the presence of airflow obstruction due to chronic bronchitis or emphysema. The airflow obstruction in COPD is due largely to structural abnormalities in the smaller airways. Important causes are inflammation, fibrosis, goblet cell metaplasia, and smooth muscle hypertrophy in terminal bronchioles.
The incidence, prevalence, and health-related costs of COPD are on the rise. Mortality due to COPD is also on the rise. In 1991, COPD was the fourth leading cause of death in the United States and had increased 33% since 1979.
COPD affects the patient's whole life, producing increasing disabilities. It has three main symptoms: cough; breathlessness; and wheeze. At first, breathlessness may be noticed when running for a bus, digging in the garden, or walking uphill. Later, it may be noticed when simply walking in the kitchen. Over time, it may occur with less and less effort until it is present all of the time.
COPD is a progressive disease and currently has no cure. Current treatments for COPD include the prevention of further respiratory damage, pharmacotherapy, and surgery. Each is discussed below.
The prevention of further respiratory damage entails the adoption of a healthy lifestyle. Smoking cessation is believed to be the single most important therapeutic intervention. However, regular exercise and weight control are also important. Patients whose symptoms restrict their daily activities or who otherwise have an impaired quality of life may require a pulmonary rehabilitation program including ventilatory muscle training and breathing retraining. Long-term oxygen therapy may also become necessary.
Pharmacotherapy may include bronchodilator therapy to open up the airways as much as possible or inhaled beta-agonists. For those patients who respond poorly to the foregoing or who have persistent symptoms, ipratropium bromide may be indicated. Further, courses of steroids, such as corticosteroids, may be required. Lastly, antibiotics may be required to prevent infections and influenza and pneumococcal vaccines may be routinely administered. Unfortunately, there is no evidence that early, regular use of pharmacotherapy will alter the progression of COPD.
About 40 years ago, it was first postulated that the tethering force that tends to keep the intrathoracic airways open was lost in emphysema and that by surgically removing the most affected parts of the lungs, the force could be partially restored. Although the surgery was deemed promising, the procedure was abandoned. The lung volume reduction surgery (LVRS) was later revived. In the early 1990's, hundreds of patients underwent the procedure. However, the number of procedures declined because Medicare stopped reimbursing for LVRS. The procedure is currently under review in controlled clinical trials. Preliminary data indicates that patients benefited from the procedure in terms of an increase in forced expiratory volume, a decrease in total lung capacity, and a significant improvement in lung function, dyspnea, and quality of life. Improvements in pulmonary function after LVRS have been attributed to at least four possible mechanisms; enhanced elastic lung recoil, correction of ventilation/perfusion mismatch, improved efficiency of respiratory musculature, and improved right ventricular filling.
Lastly, lung transplantation is also a therapeutic option. Today, COPD is the most common diagnosis for which lung transplantation is considered. Unfortunately, this consideration is given for only those with advanced COPD. Given the limited availability of donor organs, lung transplant is far from being available to all patients.
The inventions disclosed and claimed in U.S. Pat. Nos. 6,258,100 and 6,293,951, both of which are incorporated herein by reference, provide an improved therapy for treating COPD. The therapy includes non-surgical apparatus and procedures for reducing lung volume by permanently obstructing the air passageway that communicates with the portion of the lung to be collapsed. An obstruction device is placed in the air passageway that prevents inhaled air from flowing into the portion of the lung to be collapsed. This provides lung volume reduction with concomitant improved pulmonary function without the need for surgery. Various other apparatus and techniques may exist for permanently obstructing the air passageway.
Obstructing devices in an air passageway may contribute to a biological interaction with the patient, such as infection, inflammation, tissue granulation, and biological reaction. Furthermore, biological interaction may adversely affect the functionality of the obstructing device by creating unwanted buildup of biological material on the device, and compromising the ability of the obstructing device to remain in position.
In view of the foregoing, there is a need in the art for a new and improved device and method for obstructing an air passageway that controls the biological interaction between the device and the patient. The present invention is directed to a device, system, and method which provide such an improved apparatus and method for treating COPD and controlling biological reaction.
The present invention provides an intra-bronchial device that controls biological interaction of the device with the patient. The intra-bronchial device is adapted to be placed in an air passageway of a patient to collapse a lung portion associated with the air passageway. The device includes an obstructing member that prevents air from being inhaled into the lung portion to collapse the lung portion, and a medicant carried by the obstructing member. The medicant may overlie at least a portion of the obstructing member, or the medicant may be absorbed in at least a portion of the obstructing member. The obstructing member may further include an absorptive member, and the medicant is absorbed by the absorptive member.
The medicant may be selected from a group consisting of tissue growth inhibitors, tissue growth enhancers, anti-microbial agents, anti-inflammatory agents, and biological reaction inhibitors. The medicant may be arranged to control biological interaction over a period of time.
In accordance with a further embodiment, the present invention provides an intra-bronchial device and a medicant that controls biological interaction of the device with the patient. The intra-bronchial device is adapted to be placed in an air passageway of a patient to collapse a lung portion associated with the air passageway. It includes an obstructing member that prevents air from being inhaled into the lung portion to collapse the lung portion, and a cavity in the obstructing member carrying the medicant. The medicant may be selected from a group consisting of tissue growth inhibitors, tissue growth enhancers, anti-microbial agents, anti-inflammatory agents, and biological reaction inhibitors. The medicant may be arranged to control biological interaction over a period of time. The cavity may further include an absorptive member, and the medicant is absorbed by the absorptive member.
The invention further provides a method of reducing the size of a lung of a patient using an intra-bronchial device while controlling biological interaction of the device with the patient. The method includes the step of providing an intra-bronchial device that precludes air from being inhaled through an air passageway into a lung portion to be reduced in size when inserted into the air passageway communicating with the portion of the lung. The method also includes the step of associating a medicant that controls the biological interaction with the intra-bronchial device. The method further includes the step of inserting the intra-bronchial device in the air passageway. The step of associating the medicant with the intra-bronchial device may be performed before the step of implanting the device. The step of associating the medicant with the intra-bronchial device may include overlying at least a portion of the intra-bronchial device with the medicant. In an alternative embodiment, the step of associating the medicant with the intra-bronchial device includes impregnating at least a portion of the intra-bronchial device with the medicant. The method may also include the further steps of providing a cavity in the intra-bronchial device for receiving the medicant, and providing the cavity with the medicant.
The medicant may be selected from a group consisting of tissue growth inhibitors, tissue growth enhancers, anti-microbial agents, anti-inflammatory agents, and biological reaction inhibitors. The medicant may be arranged to control biological interaction over a period of time.
In yet another embodiment, the method further includes the steps of providing a cavity in the intra-bronchial device for receiving the medicant, and associating the medicant with the cavity. The cavity may include an absorptive member, and the step of associating medicant with the intra-bronchial device includes absorption of the medicant by the absorptive member. The step of associating the medicant with the intra-bronchial device may be performed before the step of implanting the device. The medicant may be selected from a group consisting of tissue growth inhibitors, tissue growth enhancers, anti-microbial agents, anti-inflammatory agents, and biological reaction inhibitors. The medicant can be arranged to control biological interaction over a period of time.
In yet a further embodiment, the invention provides a device for reducing the size of a lung of a patient. The device includes obstructing means for obstructing an air passageway communicating with a portion of the lung to be reduced in size, the obstructing means being dimensioned for insertion into the air passageway and for precluding air from being inhaled through the air passageway into the lung portion, and a means for controlling biological interaction of the obstructing means with the patient.
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may best be understood by making reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like referenced numerals identify identical elements, and wherein:
The respiratory system 20 includes the trachea 28, the left mainstem bronchus 30, the right mainstem bronchus 32, the bronchial branches 34, 36, 38, 40, and 42 and sub-branches 44, 46, 48, and 50. The respiratory system 20 further includes left lung lobes 52 and 54 and right lung lobes 56, 58, and 60. Each bronchial branch and sub-branch communicates with a respective different portion of a lung lobe, either the entire lung lobe or a portion thereof. As used herein, the term “air passageway” is meant to denote either bronchi or bronchioles, and typically means a bronchial branch or sub-branch which communicates with a corresponding individual lung lobe or lung lobe tissue portion to provide inhaled air thereto or conduct exhaled air therefrom.
Characteristic of a healthy respiratory system is the arched or inwardly arcuate diaphragm 26. As the individual inhales, the diaphragm 26 straightens to increase the volume of the thorax 22. This causes a negative pressure within the thorax. The negative pressure within the thorax in turn causes the lung lobes to fill with air. When the individual exhales, the diaphragm returns to its original arched condition to decrease the volume of the thorax. The decreased volume of the thorax causes a positive pressure within the thorax that in turn causes exhalation of the lung lobes.
It has been found that the apex portions 62 and 66 of the upper lung lobes 52 and 56, respectively, are most affected by COPD. Hence, bronchial sub-branch obstructing devices are generally employed for treating the apex 66 of the right, upper lung lobe 56. However, as will be appreciated by those skilled in the art, the present invention may be applied to any lung portion without departing from the present invention. As will be further appreciated by those skilled the in art, the present invention may be used with any type of obstructing member to permit mucociliary transport. The inventions disclosed and claimed in U.S. Pat. Nos. 6,258,100 and 6,293,951, both of which are incorporated herein by reference, provide an improved therapy for treating COPD by obstructing an air passageway using an intra-bronchial device, such as a valve or plug. The present invention may be used with the apparatus, system, and methods of these patents as will be briefly described in conjunction with the disclosure of the preferred embodiments of the present invention.
The insertion of an obstructing member treats COPD by deriving the benefits of lung volume reduction surgery without the need of performing the surgery. The treatment contemplates permanent partial or complete collapse of a lung portion to reduce lung mass. This leaves extra volume within the thorax for the diaphragm to assume its arched state for acting upon the remaining healthier lung tissue. As previously mentioned, this should result in improved pulmonary function due to enhanced elastic recoil, correction of ventilation/perfusion mismatch, improved efficiency of respiratory musculature, and improved right ventricle filling.
More specifically, the obstructing member 90 has an outer dimension 91, and when expanded, enables contact with the air passageway inner dimension 51. This seals the air passageway upon placement of the obstructing member 90 in the air passageway 50 for maintaining the lung portion 66 in the collapsed state. A function of the intra-bronchial device disclosed and claimed in the specification, including the detailed description and the claims, is described in terms of collapsing a lung portion associated with an air passageway. In some lungs, a portion of a lung may receive air from collateral air passageways. Obstructing one of the collateral air passageways may reduce the volume of the lung portion associated with the air passageway, but not completely collapse the lung portion as that term may be generally understood. As used herein, the meaning of “collapse” includes a complete collapse, a partial collapse, and a reduction in volume of a lung portion.
Alternatively, the lung portion 66 may be collapsed using vacuum prior to placement of obstructing member 90, or it may be collapsed by sealing the air passageway 50 with obstructing member 90. Over time, the air within the lung portion 66 will be absorbed by the body and result in the collapse of lung portion 66. Alternatively, obstructing member 90 may include a one-way valve allowing air to escape from lung portion 66. Lung portion 66 will then collapse, and the valve will prevent air from being inhaled.
Inserting obstructing member 90 into air passageway 50 may result in biological interaction with the patient that adversely affects the patient or the performance of obstructing member 90. Possible interactions include tissue granulation, infection, inflammation, and fibrotic response. For example, the presence of obstructing member 90 in the air passageway 50 may invoke the body's healing process. The healing process may involve tissue granulation and connective tissue projections that could interfere with the intra-bronchial device. The tissue granulation may begin on insertion of obstructing member 90, or sometime later. By way of another example, the presence of obstructing member 90 may result in a potential for infection or inflammation, which could occur on insertion of obstructing member 90 or sometime later. In a further example, the presence of obstructing member 90 in the air passageway 50 may invoke the patient's fibrotic response, which could interfere with obstructing member 90.
In accordance with the broader aspects of the present invention, a medicant is associated with an obstructing member of an intra-bronchial device for release to control biological interaction of the intra-bronchial device with the patient. The medicant may be associated with the obstructing member in many different ways. It may be carried on proximal, distal, or both proximal and distal portions of the device as may be required by the biological reaction to be controlled and the limitations of a selected medicant.
Alternative embodiments of the invention may include associating medicant 105 by impregnation, co-mixing, or absorption into obstructing member 90 in any manner known to those skilled in the art, and as required by biological reaction to be controlled and the limitations of the selected medicant 105. For example, an anti-microbial medicant 105 may be absorbed into at least a portion of obstructing member 90.
Still further, the medicant may be carried on an element of an intra-bronchial device, which in turn is carried by obstructing member. Such elements may include structural members, or anchors for example.
The medicant 105 carried by, or associated with, the obstructing member 90 may be selected from any class suitable for controlling biological interaction of the intra-bronchial device with the patient. These classes include tissue growth inhibitors, such as paclitaxel sold under the trademark Taxol™ of the Bristol-Meyers Co., that may stop cells from dividing and growing on obstructing member 90 so that they eventually die; tissue growth enhancers such as tissue growth factors; anti-microbial agents to prevent or resist seeding of bacteria on obstructing member 90, such as an anti-microbial compound that permits a continuous, controlled release of ionic silver over an extended time period sold as AgION™ of Agion Technologies, L.L.C.; and biological reaction inhibitors, such as parylene, a common generic name for a unique series of polymers based on paraxylene that enhance biotolerence of medical devices used within the body, such as obstructing member 90. Further, the medicant 105 may be selected or arranged to control biological interaction over a period of time. The medicant may be associated with obstructing member 90 either before it is inserted into air passageway 50 or after, or renewed after insertion.
The embodiments of the invention illustrated in
In addition to generalized control of biological interaction, localized control of biological interaction may be provided by associating medicant 105 with a selected portion of an obstructive member, such as the one-way valve obstructing member 120. For example, fibrotic tissue might tend to grow across slit 122 and prevent the one-way valve structure from functioning. Medicant 105 may be selected to suppress such a fibrotic response, and associated with one-way valve obstructing member 120 in any manner previously described. As illustrated in
Another aspect of the invention provides for targeted expression of biological response by a selected medicant. For example, a particular medicant may be selected to promote tissue granulation. Such tissue granulation may be desired to assist in device anchoring. The medicant 105 would be associated with the device at a site, such as the outer surface of the sidewall 136, where tissue granulation would assist in the anchoring of the obstructing member 120 to an air passageway.
The effectiveness of intra-bronchial device 200 may depend in part on the anchor 220 being retained in the air passageway and the growth of the epithelial membrane 97 on the interior portion of the anchor 220. A medicant 105 selected to promote tissue granulation may be associated with the anchor 220 to assist in anchoring intra-bronchial device 200. Further, a medicant 105 selected to promote growth of epithelial membrane 97 on the interior may also be associated with the anchor 220 to assist with re-epithelialization.
The piercing by projections 312, 314, 316, and 318 into the air passageway wall 100 may result in adverse effects on the patient or the performance of the intra-bronchial device 300, such as infection, inflammation, or rejection. A medicant 105 (illustrated schematically) may be selected and associated with intra-bronchial device at projections 312, 314, 316, and 318, or elsewhere, to control any adverse biological interaction, or to encourage a biological reaction to retain projections 312, 314, 316, and 318 in place.
As can thus be seen from the foregoing, the present invention provides a device, system, and method for controlling biological interaction of an intra-bronchial obstruction device with the patient. Biological interaction is controlled by providing a medicant associated with the intra-bronchial obstruction device, present at either the time of placement or associated after placement.
While particular embodiments of the present invention have been shown and described, modifications may be made, and it is therefore intended in the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention.
The present application is a continuation of U.S. application Ser. No. 10/081,712, filed Feb. 21, 2002, the entire contents of which is incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
Parent | 10081712 | Feb 2002 | US |
Child | 11417553 | May 2006 | US |