Implantable medical devices for tissue repositioning

A medical device for repositioning tissue within an animal has a main body with a first end portion, a second end portion, and a middle portion. The first end portion defines a series of passageways and the second end portion defines a bulbous shape, a slot, and a tab portion. Methods of treating obstructive sleep apnea are also described.

FIELD

The disclosure relates to the field of medical devices. More particularly, the disclosure relates to implantable medical devices useful for repositioning tissue within an animal, such as a human. Specific examples relate to implantable medical devices for repositioning a palatopharyngeus muscle in the treatment of obstructive sleep apnea. The invention also relates to methods of treating obstructive sleep apnea.

BACKGROUND

It is sometimes necessary or desirable to reposition a tissue or portion of a tissue within the body of an animal, such as a human, to accomplish a treatment objective. For example, in the treatment of obstructive sleep apnea, it may be desirable to adjust the position of one or more tissues or portions of tissue, such as a palatopharyngeus muscle of a patient suffering from obstructive sleep apnea.

Obstructive sleep apnea, sometimes referred to as OSA, is a clinical disorder in which a partial or complete collapse of soft tissue occurs in the airway during sleep. This leads to a blockage of the airway and impaired breathing during sleep. Left untreated, obstructive sleep apnea can lead to fatigue, reduced alertness following sleep, and a general reduction in productivity for the affected individual. More severe obstructive sleep apnea is associated with sleep deprivation, hypoxemia, increased morbidity including elevated risk for cardiovascular disease and stroke, and depression.

Several anatomic factors can contribute to the development of obstructive sleep apnea, individually or collectively, including tongue and soft palate obstruction of the airway. Enlargement and/or collapse of the palatopharyngeus muscles can also obstruct the airway and contribute to the development of obstructive sleep apnea. This muscle contracts to move the pharynx during swallowing to prevent the bolus from entering the nasopharynx. Together with the mucous membrane that covers its entire surface, the palatopharyngeus muscle forms the palatopharyngeus arch.

Treating obstructive sleep apnea that stems in whole or in part from airway obstruction by the palatopharyngeus muscle presents challenges that are different than those associated with treating obstructive sleep apnea related to tongue and/or soft palate associated airway obstruction, particularly due to the location and function of the muscle. Collapse may include the level of the palate and retropalatal airway and more inferiorly at the level of the oropharynx. Indeed, currently available treatments for obstructive sleep apnea having a palatopharyngeus muscle component, which focus on surgical alteration of the muscle, may result in difficulty in swallowing, undesirable scarring, altering the anatomy, and other drawbacks. Furthermore, these techniques frequently do not provide a desired degree of airway clearance. Considering the possibility that surgery may provide insufficient clearance and leave the patient with swallowing and/or other new challenges, currently available approaches do not provide a clear path to successful treatment for people suffering with obstructive sleep apnea.

A need exists, therefore, for new and improved approaches to the treatment of obstructive sleep apnea associated with airway obstruction caused by the palatopharyngeus muscle. A need also exists for new and improved medical devices for repositioning tissue within an animal.

BRIEF DESCRIPTION OF SELECTED EXAMPLES

Medical devices useful in the repositioning of tissue within an animal are described.

An example medical device comprises a main body having a lengthwise axis, a first terminal end, an opposing second terminal end, a first side, a second opposing side, a first surface, a second opposing surface, and a longitudinal midpoint disposed on the lengthwise axis between the first terminal end and the second terminal end and between the first side and the second side, the second terminal end defining an arc that extends from a first arc base on the first side to a second arc base on the second side, the main body having a first width at the first terminal end extending orthogonally to the longitudinal axis from the first side to the second side, and a second width extending orthogonally to the longitudinal axis from the first arc base on the first side to the second arc base on the second side; the main body defining a first end portion extending along the lengthwise axis from the first terminal end toward but not to the longitudinal midpoint, a second end portion extending along the lengthwise axis from the second terminal end toward but not to the longitudinal midpoint, and a middle portion extending along the lengthwise axis between the first end portion and second end portion and including the longitudinal midpoint; the first end portion of the main body defining a series of passageways, each passageway of the series of passageways extending through the main body from the first surface to the second surface; the second end portion and the middle portion of the main body being free of any passageways extending through the main body from the first surface to the second surface; and the second end portion of the main body defining a semi-circular slot extending through the main body from the first surface to the second surface and having a first slot edge and a second slot edge, and a tab portion extending between the second slot edge and the second terminal end of the main body.

Another example medical device comprises a main body having a lengthwise axis, a first terminal end, an opposing second terminal end, a first side, a second opposing side, a first surface, a second opposing surface, and a longitudinal midpoint disposed on the lengthwise axis between the first terminal end and the second terminal end and between the first side and the second side, the second terminal end defining an arc that extends from a first arc base on the first side to a second arc base on the second side, the main body having a first width at the first terminal end extending orthogonally to the longitudinal axis from the first side to the second side, and a second width extending orthogonally to the longitudinal axis from the first arc base on the first side to the second arc base on the second side; the main body defining a first end portion extending along the lengthwise axis from the first terminal end toward but not to the longitudinal midpoint, a second end portion extending along the lengthwise axis from the second terminal end toward but not to the longitudinal midpoint, and a middle portion extending along the lengthwise axis between the first end portion and second end portion and including the longitudinal midpoint; the first end portion of the main body defining a series of passageways, each passageway of the series of passageways extending through the main body from the first surface to the second surface; the second end portion and the middle portion of the main body being free of any passageways extending through the main body from the first surface to the second surface; and the second end portion of the main body defining a semi-ovular slot extending through the main body from the first surface to the second surface and having a first slot edge and a second slot edge, and a tab portion extending between the second slot edge and the second terminal end of the main body.

Another example medical device comprises a main body having a lengthwise axis, a first terminal end, an opposing second terminal end, a first side, a second opposing side, a first surface, a second opposing surface, and a longitudinal midpoint disposed on the lengthwise axis between the first terminal end and the second terminal end and between the first side and the second side, the second terminal end defining an arc that extends from a first arc base on the first side to a second arc base on the second side, the main body having a first width at the first terminal end extending orthogonally to the longitudinal axis from the first side to the second side, and a second width extending orthogonally to the longitudinal axis from the first arc base on the first side to the second arc base on the second side; the main body defining a first end portion extending along the lengthwise axis from the first terminal end toward but not to the longitudinal midpoint, a second end portion extending along the lengthwise axis from the second terminal end toward but not to the longitudinal midpoint, and a middle portion extending along the lengthwise axis between the first end portion and second end portion and including the longitudinal midpoint; the first end portion of the main body defining a series of passageways, each passageway of the series of passageways extending through the main body from the first surface to the second surface; the second end portion and the middle portion of the main body being free of any passageways extending through the main body from the first surface to the second surface; and the second end portion of the main body defining a rectangular slot extending through the main body from the first surface to the second surface and having a first slot edge and a second slot edge, and a tab portion extending between the second slot edge and the second terminal end of the main body.

Another example medical device comprises a main body having a lengthwise axis, a first terminal end, an opposing second terminal end, a first side, a second opposing side, a first surface, a second opposing surface, and a longitudinal midpoint disposed on the lengthwise axis between the first terminal end and the second terminal end and between the first side and the second side, the second terminal end defining an arc that extends from a first arc base on the first side to a second arc base on the second side, the main body having a first width at the first terminal end extending orthogonally to the longitudinal axis from the first side to the second side, and a second width extending orthogonally to the longitudinal axis from the first arc base on the first side to the second arc base on the second side; the main body defining a first end portion extending along the lengthwise axis from the first terminal end toward but not to the longitudinal midpoint, a second end portion extending along the lengthwise axis from the second terminal end toward but not to the longitudinal midpoint, and a middle portion extending along the lengthwise axis between the first end portion and second end portion and including the longitudinal midpoint; the first end portion of the main body defining a series of passageways, each passageway of the series of passageways extending through the main body from the first surface to the second surface; and the second end portion of the main body defining a bulbous shape, a slot extending through the main body from the first surface to the second surface and having a first slot edge and a second slot edge, and a tab portion extending between the second slot edge and the second terminal end of the main body.

Methods for treating obstructive sleep apnea are also described.

An example method of treating obstructive sleep apnea comprises creating a mucosal incision in the arch of the posterior tonsillar pillar to expose the palatopharyngeus muscle, or removing the tonsils if desirable; isolating the palatopharyngeus muscle from the mucosa to create a clearance behind the palatopharyngeus muscle; inserting one end of a medical device according to an embodiment into the clearance; wrapping the medical device around the palatopharyngeus muscle; passing one end of the medical device through the slot of the medical device; pulling one end of the medical device to create a snug fit of the medical device around the palatopharyngeus muscle; placing the end of the medical device that was passed through the slot into the palatoglossus muscle toward the hammulus; placing a suture through a passageway through the main body of the medical device; and securing the suture to tissue to lateralize the palatopharyngeus muscle.

Another example method of treating obstructive sleep apnea comprises palpating the soft palate to ensure no evidence of a submucosal cleft is found; creating a mucosal incision in the arch of the posterior tonsillar pillar to expose the palatopharyngeus muscle, or removing the tonsils if desirable; isolating the palatopharyngeus muscle to create a clearance behind the palatopharyngeus muscle; inserting one side of a medical device according to an embodiment into to the clearance; wrapping the medical device around the palatopharyngeus muscle; passing one end of the medical device through the slot of the medical device; pulling one end of the medical device to create a snug fit of the medical device around the palatopharyngeus muscle; placing a suture through a passageway through the main body of the medical device near the narrow end of the medical device; advancing the narrow end of the medical device deep to the palatoglossus muscle toward the hammulus; retrieving a needle from the mucosa overlying the hammulus; reintroducing the needle into the mucosa and tunneling medially in the submucosa toward the mucosal incision; securing the suture to tissue to lateralize the palatopharyngeus muscle; and closing the incision with a suitable closure device, such as one or more sutures.

Additional understanding of the inventive medical devices and their use can be obtained by reviewing the detailed description of selected examples, below, with reference to the appended drawings.

DETAILED DESCRIPTION OF SELECTED EXAMPLES

The following detailed description and the appended drawings describe and illustrate various example medical devices and methods for their use. The description and illustration of these examples are provided to enable one skilled in the art to make and use the inventive medical devices and to perform the inventive methods of their use. They are not intended to limit the scope of the protection sought or provided in any manner.

As used herein, the term ‘slot’ refers to a passageway that extends through the entire thickness of a member. The term does not require any particular size, shape, or configuration of the passageway.

FIGS. 1 through 3illustrate a first example medical device100. The medical device100is a sling that is suitable for repositioning the palatopharyngeus muscle of an animal, such as a human. The medical device100has a main body110comprising a substantially flat member extending from a first terminal end112to an opposing second terminal end114and having first116and second118opposing sides. The main body110has a first120or upper surface and an opposing second122or lower surface. The main body110has a lengthwise axis124and a transverse axis126that orthogonally intersects the lengthwise axis124at a longitudinal midpoint128disposed on the lengthwise axis124. The main body has a thickness130measured from the first surface120to the opposing second surface122. A first end portion132extends along the lengthwise axis124, includes the first terminal end112, and extends toward but not to the longitudinal midpoint128. A second end portion134extends along the lengthwise axis124, includes the second terminal end114, and extends toward but not to the longitudinal midpoint128. A middle portion136extends along the lengthwise axis124, between the first end portion132and second end portion134, and includes the longitudinal midpoint128.

The main body110defines a series of passageways140. Each passageway of the series of passageways140extends through the entire thickness130of the main body110, from the first surface120to the second surface122.FIG. 3shows first140aand second140bpassageways of the series of passageways140. In the illustrated embodiment, both the first end portion132and the middle portion136includes passageways of the series of passageways140, while the second end portion134is free of passageways of the series of passageways140. In some embodiments, it may be desirable to include a middle portion that is also free of passageways of the series of passageways.

The main body110has a first width142at the first terminal end112that extends orthogonally to the longitudinal axis124from the first side116to the second side118. The second terminal end114defines an arc144that extends from a first arc base146on the first side116to a second arc base148on the second side118. The main body110has a second width150that extends orthogonally to the longitudinal axis124from the first arc base146on the first side116to the second arc base148on the second side118. The second width150is greater than the first width142such that the first116and second118sides extend away from each other with respect to the longitudinal axis124moving from the first terminal end112to the second terminal end114.

The second end portion134of the main body110defines a slot160. The slot160is a passageway that extends through the entire thickness130of the main body110, from the first surface120to the second surface122. In the illustrated embodiment, the slot160has a semi-circular shape and is sized to allow the first terminal end112and the first end portion132to be slidably passed through the slot160when the first terminal end112is passed back toward the second terminal end114. The slot can have any suitable shape and a skilled artisan will be able to select an appropriate shape for a medical device according to a particular embodiment based on various considerations, including any desired ease with which the first terminal end of the medical device can be passed through the slot. The slot should be sized, however, such that the first terminal end and at least a portion of the first end portion of the medical device can be passed through the slot.

In the illustrated embodiment, the slot160is a semi-circular portion of a circle having a radius162that is less than the first width142. Thus, the slot160has a maximum dimension measured along or parallel to the longitudinal axis124that is less than the first width142. While other relative sizings of the maximum longitudinal dimension of the slot and the width of the main body at the first terminal end can be used in medical devices according to particular embodiments, this relative sizing in the illustrated embodiment is considered advantageous at least because it sets the slot160as a physical barrier to insertion of the first terminal end112into the slot in a twisted manner, which can ensure that the first terminal end112is inserted such that no twisting of the main body occurs when disposing the medical device around a tissue during use. Also in the illustrated embodiment, the slot160has a slot width164that extends orthogonally to the longitudinal axis124from the first slot side166to a second slot side168. The slot160has a first slot edge170that is linear or substantially linear and a second slot edge172that defines an arc174. The first slot edge170extends orthogonally to the longitudinal axis124and is disposed closer to the first terminal end112than the second slot edge172, while the second slot edge172is disposed closer to the second terminal end114than the first slot edge170.

The second end portion134defines a tab portion180extending between the second slot edge172and the second terminal end114. In the illustrated embodiment, the tab portion180extends along the longitudinal axis124from the second slot edge172to the first116and second118sides and the second terminal end114. As such, the tab portion180has a generally arcuate shape with flat portions provided by the sides116,118. The tab portion180has an axial length182extending along the longitudinal axis124that is greater than the radius162of the slot180.

In the illustrated embodiment, the first120and second122surfaces of the main body110are substantially flat. It is noted, though, that it may be advantages to include one or more bumps, projections or other surface modifications on one or both of the surfaces120,122. Inclusion of such modifications may improve the handling of the medical device100during use.

FIGS. 4 and 5illustrate the first example medical device100disposed around a palatopharyngeus muscle200. The first terminal end112has been doubled back onto the medical device100and passed through the slot160such that the medical device100encircles the palatopharyngeus muscle200. To achieve this positioning, the first terminal end112has been passed through the slot160and behind the tab portion180. The medical device100has been cinched around the palatopharyngeus muscle200by pulling the first distal end112to snug the medical device100against the palatopharyngeus muscle200. Also, the palatopharyngeus muscle has been moved from an original position202, shown in phantom, in the direction indicated by arrow204, to a new position206by pulling the first end portion132of the medical device100generally in the direction indicated by arrow204. To maintain the new position206of the palatopharyngeus muscle200, a suture220has been passed through a passageway140cof the series of passageways140, through a portion of an adjacent tissue250, and knotted or otherwise fixed to secure the first end portion132against the adjacent tissue250.

As best illustrated inFIG. 5, the cinching of the medical device100around the palatopharyngeus muscle200may create a void270bounded by the first120or upper surface of the medical device100and the outer surface208of the palatopharyngeus muscle200. It is noted that the muscle may flatten or otherwise morph to fill or substantially fill the space created by the cinching of the medical device100around the palatopharyngeus muscle200.

FIGS. 6 and 7illustrate a second example medical device300. The medical device300is similar to the medical device100described above, except as detailed below. Thus, the medical device300has a main body310comprising a substantially flat member extending from a first terminal end312to an opposing second terminal end314and having first316and second318opposing sides. The main body310has a first320or upper surface and an opposing second322or lower surface. The main body310has a lengthwise axis324and a transverse axis326that orthogonally intersects the lengthwise axis324at a longitudinal midpoint328disposed on the lengthwise axis324. The main body has a thickness330measured from the first surface320to the opposing second surface322. A first end portion332extends along the lengthwise axis324, includes the first terminal end312, and extends toward but not to the longitudinal midpoint328. A second end portion334extends along the lengthwise axis324, includes the second terminal end314, and extends toward but not to the longitudinal midpoint328. A middle portion336extends along the lengthwise axis324, between the first end portion332and second end portion334, and includes the longitudinal midpoint328. The main body310defines a series of passageways340. Each passageway of the series of passageways340extends through the entire thickness330of the main body310, from the first surface320to the second surface322. The main body310has a first width342at the first terminal end312that extends orthogonally to the longitudinal axis324from the first side316to the second side318. The second terminal end314defines an arc344that extends from a first arc base346on the first side316to a second arc base348on the second side318. The main body310has a second width350that extends orthogonally to the longitudinal axis324from the first arc base346on the first side316to the second arc base348on the second side318. The second width350is greater than the first width342such that the first316and second318sides extend away from each other with respect to the longitudinal axis324moving from the first terminal end312to the second terminal end314.

The second end portion334of the main body310defines a slot360. The slot360is a passageway that extends through the entire thickness330of the main body310, from the first surface320to the second surface322.

The second end portion334defines a tab portion380extending between the second slot edge372and the second terminal end314. The tab portion380has an axial length382extending along the longitudinal axis324that is greater than the radius362of the slot380.

In this embodiment, tab portion380defines a tab passageway390that extends through the entire thickness330of main body310from the first surface320to the second surface322. If included in a medical device according to a particular embodiment, a tab passageway can be included at any suitable location on the tab of the medical device. In the illustrated embodiment, tab passageway390is disposed on the longitudinal axis324of the medical device300, with the center of the tab passageway390equidistant from the second slot edge372and the second terminal end314. This positioning is considered advantageous at least because it maximizes the amount of material of the main body310between the tab passageway390, the second terminal end314, and the second slot edge372. This is expected to provide beneficial engagement between a suture, the tab portion380and the first portion332of the medical device in use, as described in more detail below.

FIGS. 8 and 9illustrate the second example medical device300disposed around a palatopharyngeus muscle400. The first terminal end312has been doubled back onto the medical device300and passed through the slot360such that the medical device300encircles the palatopharyngeus muscle400. To achieve this positioning, the first terminal end312has been passed through the slot360and behind the tab portion380. The medical device300has been cinched around the palatopharyngeus muscle400by pulling the first distal end312to snug the medical device300against the palatopharyngeus muscle400. Also, once, the palatopharyngeus muscle400has been moved from an original position402, shown in phantom, in the direction indicated by arrow404, to a new position406by pulling the first end portion332of the medical device300generally in the direction indicated by arrow404. To maintain the new position406of the palatopharyngeus muscle400, a suture420has been passed through a passageway340cof the series of passageways340, through a portion of an adjacent tissue450, and knotted or otherwise fixed to secure the first end portion332against the adjacent tissue450.

A second suture460has been passed through the tab passageway390and a passageway of the series of passageways340on the main body310. As best illustrated inFIG. 9, this second suture460has been knotted or otherwise fixed to secure the second surface322in the tab portion380against the second surface322in the first end portion332of the main body310. Also as best illustrated inFIG. 9, this securement provided by the second suture460allows the medical device300to be maintained in a position in which the void470bounded by the first320or upper surface of the medical device300and the outer surface408of the palatopharyngeus muscle400is smaller than the void270achieved with the first example medical device100, as best illustrated inFIG. 5. This ability to secure the medical device300in a position having a relatively small void470is considered advantageous at least because it provides more contact surface area between the medical device300and the palatopharyngeus muscle300. Furthermore, the inclusion of the tab passageway390is considered particularly advantageous for medical devices formed entirely or partially of remodelable materials at least because it enables contact between adjacent surfaces of the medical device300, as best illustrated inFIG. 9, which is expected to aid remodeling efforts.

FIG. 10illustrates a third example medical device500. The medical device500is similar to the medical device100described above, except as detailed below. Thus, the medical device500has a main body510comprising a substantially flat member extending from a first terminal end512to an opposing second terminal end514and having first516and second518opposing sides. The main body510has a first520or upper surface and an opposing second or lower surface (not visible inFIG. 10). The main body510has a lengthwise axis524and a transverse axis526that orthogonally intersects the lengthwise axis524at a longitudinal midpoint528disposed on the lengthwise axis524. The main body510has a thickness measured from the first surface520to the opposing second surface. A first end portion532extends along the lengthwise axis524, includes the first terminal end512, and extends toward but not to the longitudinal midpoint528. A second end portion534extends along the lengthwise axis524, includes the second terminal end514, and extends toward but not to the longitudinal midpoint528. A middle portion536extends along the lengthwise axis524, between the first end portion532and second end portion534, and includes the longitudinal midpoint528. The main body510defines a series of passageways540. Each passageway of the series of passageways540extends through the entire thickness530of the main body510, from the first surface520to the second surface. The main body510has a first width542at the first terminal end512that extends orthogonally to the longitudinal axis524from the first side516to the second side518. The second terminal end514defines an arc544that extends from a first arc base546on the first side516to a second arc base548on the second side518. The main body510has a second width550that extends orthogonally to the longitudinal axis524from the first arc base546on the first side516to the second arc base548on the second side518. The second width550is greater than the first width542such that the first516and second518sides extend away from each other with respect to the longitudinal axis524moving from the first terminal end512to the second terminal end514.

The second end portion534of the main body510defines a slot560. The slot560is a passageway that extends through the entire thickness of the main body510, from the first surface520to the second surface. In the illustrated embodiment, the slot560is a semi-ovular, i.e., half oval, portion of an oval having a minor radius562that is less than the first width542. Thus, the slot560has a maximum dimension measured along or parallel to the longitudinal axis524that is less than the first width542. The slot560has a slot width564that extends orthogonally to the longitudinal axis524from the first slot side566to a second slot side568. The slot560has a first slot edge570that is linear or substantially linear and a second slot edge572that defines an arc574. The first slot edge570extends orthogonally to the longitudinal axis524and is disposed closer to the first terminal end512than the second slot edge572, while the second slot edge572is disposed closer to the second terminal end514than the first slot edge570.

The second end portion534defines a tab portion580extending between the second slot edge572and the second terminal end514. In this embodiment, the tab portion580has an axial length582extending along the longitudinal axis524that is less than the radius562of the slot560.

Each passageway of the series of passageways540extends through the entire thickness of the main body510, from the first surface520to the second surface. In this embodiment, the series of passageways540includes first540a, second540b, third540c, and fourth540dpassageways. Each of the first540a, second540b, third540c, and fourth540dpassageways is disposed on the first end portion532, while the middle portion536is free of passageways, and the second end portion534is free of passageways except for the slot560. This structural configuration is considered particularly advantageous for medical devices, such as the illustrated example medical device500, in which the tab portion580has an axial length582that is less than the radius of the slot562that extends along the longitudinal axis524of the medical device500.

FIG. 11illustrates the third example medical device500disposed around a palatopharyngeus muscle600within an oral cavity690of a patient. The first terminal end512has been doubled back onto the medical device500and passed through the slot560such that the medical device500encircles the palatopharyngeus muscle600. To achieve this positioning, the first terminal end512has been passed through the slot560and behind the tab portion580. The medical device500has been cinched around the palatopharyngeus muscle600by pulling the first distal end512to snug the medical device500against the palatopharyngeus muscle600. The palatopharyngeus muscle600has been moved from an original position to the desired new position illustrated in the Figure by pulling the first end portion532of the medical device500. To maintain the new position of the palatopharyngeus muscle600, a suture620has been passed through a passageway540aof the series of passageways540, through a portion of an adjacent tissue650, and knotted or otherwise fixed to secure the first end portion532against the adjacent tissue650. The first end portion532has been disposed within a tunnel670created in adjacent tissue650prior to placement of the suture620and, therefore, prior to fixation of the first end portion532of the medical device500to the adjacent tissue650. The tunnel670can be a natural opening, cavity, passageway or other void in a tissue, or, as in the procedure illustrated in the Figure, can be an artificial tunnel created for the purpose of receiving the first end portion532of the medical device, such as a tunnel created by basic blunt dissection techniques.

FIG. 12illustrates a fourth example medical device700. The medical device700is similar to the medical device100described above, except as detailed below. Thus, the medical device700has a main body710comprising a substantially flat member extending from a first terminal end712to an opposing second terminal end714and having first716and second718opposing sides. The main body710has a first720or upper surface and an opposing second or lower surface (not visible inFIG. 12). The main body710has a lengthwise axis724and a transverse axis726that orthogonally intersects the lengthwise axis724at a longitudinal midpoint728disposed on the lengthwise axis724. The main body710has a thickness measured from the first surface720to the opposing second surface. A first end portion732extends along the lengthwise axis724, includes the first terminal end712, and extends toward but not to the longitudinal midpoint728. A second end portion734extends along the lengthwise axis724, includes the second terminal end714, and extends toward but not to the longitudinal midpoint728. A middle portion736extends along the lengthwise axis724, between the first end portion732and second end portion734, and includes the longitudinal midpoint728. The main body710defines a series of passageways740. Each passageway of the series of passageways740extends through the entire thickness of the main body710, from the first surface720to the second surface. In this embodiment, the series of passageways740includes first740a, second740b, third740c, and fourth740dpassageways.

The main body710has a first width742at the first terminal end712that extends orthogonally to the longitudinal axis724from the first side716to the second side718. The second terminal end714defines an arc744that extends from a first arc base746on the first side716to a second arc base748on the second side718. The main body710has a second width750that extends orthogonally to the longitudinal axis724from the first arc base746on the first side716to the second arc base748on the second side718. The second width750is greater than the first width742such that the first716and second718sides extend away from each other with respect to the longitudinal axis724moving from the first terminal end712to the second terminal end714.

The second end portion734of the main body710defines a slot760. The slot760is a passageway that extends through the entire thickness of the main body710, from the first surface720to the second surface. In the illustrated embodiment, the slot760is a rectangular opening having a minor width762that is less than the first width742. Thus, the slot760has a maximum dimension measured along or parallel to the longitudinal axis724that is less than the first width742. The slot760has a slot width764that extends orthogonally to the longitudinal axis724from the first slot side766to a second slot side768. The slot760has first770and second772slot edges, each of which is linear or substantially linear. The first slot edge770extends orthogonally to the longitudinal axis724and is disposed closer to the first terminal end712than the second slot edge772, while the second slot edge772is disposed closer to the second terminal end714than the first slot edge770.

The second end portion734defines a tab portion780extending between the second slot edge772and the second terminal end714. In this embodiment, the tab portion780has an axial length782extending along the longitudinal axis724that is greater than the minor width762of the rectangular slot780. In embodiments in which the slot is rectangular, such as the example medical device700illustrated inFIG. 12, it is considered advantageous to include a tab portion780having an axial length782that is between about two and about three times the minor width762of the slot760. In the illustrated embodiment, the tab portion780has an axial length782that is about 2.5 times the minor width762of the slot760. This structural arrangement is considered particularly advantageous at least because it provides a balance between a desired ability to position the first terminal end712through the slot760and to minimize the profile of the medical device700following implantation.

FIG. 13illustrates a fifth example medical device800. The medical device800is similar to the medical device800described above, except as detailed below. Thus, the medical device800has a main body810comprising a substantially flat member extending from a first terminal end812to an opposing second terminal end814and having first816and second818opposing sides. The main body810has a first820or upper surface and an opposing second or lower surface (not visible inFIG. 12). The main body810has a lengthwise axis824and a transverse axis826that orthogonally intersects the lengthwise axis824at a longitudinal midpoint828disposed on the lengthwise axis824. The main body810has a thickness measured from the first surface820to the opposing second surface. A first end portion832extends along the lengthwise axis824, includes the first terminal end812, and extends toward but not to the longitudinal midpoint828. A second end portion834extends along the lengthwise axis824, includes the second terminal end814, and extends toward but not to the longitudinal midpoint828. A middle portion836extends along the lengthwise axis824, between the first end portion832and second end portion834, and includes the longitudinal midpoint828. The main body810defines a series of passageways840. Each passageway of the series of passageways840extends through the entire thickness of the main body810, from the first surface820to the second surface. In this embodiment, the series of passageways840includes first840a, second840b, third840c, and fourth840dpassageways.

The main body810has a first width842at the first terminal end812that extends orthogonally to the longitudinal axis824from the first side816to the second side818. The second terminal end814defines an arc844that extends from a first arc base846on the first side816to a second arc base848on the second side818. The main body810has a second width850that extends orthogonally to the longitudinal axis824from the arc844on the first side816to the arc844on the second side818. The second width850is greater than the first width842such that the first816and second818sides extend away from each other with respect to the longitudinal axis824moving from the first terminal end812to the second terminal end814.

The second end portion834of the main body810defines a slot860. The slot860is a passageway that extends through the entire thickness of the main body810, from the first surface820to the second surface. In the illustrated embodiment, the slot860is a rectangular opening having a minor width862that is less than the first width842. Thus, the slot860has a maximum dimension measured along or parallel to the longitudinal axis824that is less than the first width842. The slot860has a slot width864that extends orthogonally to the longitudinal axis824from the first slot side866to a second slot side868. The slot860has first870and second872slot edges, each of which is linear or substantially linear. The first slot edge870extends orthogonally to the longitudinal axis824and is disposed closer to the first terminal end812than the second slot edge872, while the second slot edge872is disposed closer to the second terminal end814than the first slot edge870.

The second end portion834defines a tab portion880extending between the second slot edge872and the second terminal end814. In this embodiment, the tab portion880has an axial length882extending along the longitudinal axis824that is greater than the minor width862of the rectangular slot880. In the illustrated embodiment, the tab portion880has an axial length882that is about three times the minor width862of the slot860.

In this embodiment, The second end portion834is bulbous-shaped such that the outer edge881is not a natural extension of the linear path of either side816,818of the medical device800. To achieve this structure, each of the first arc base846and second arc base848are disposed axially between the first slot edge870and the first terminal end812. Furthermore, a first arc extension847extends from the first arc base846to the linear path of the first side816and a second arc extension849extends from the second arc base848to the linear path of the second side818. This bulbous-shaped structural arrangement, is considered particularly advantageous at least because it provides an enhanced ability to snug the second end portion834against the palatopharyngeus muscle during implantation without adding significantly to the overall profile of the medical device800.

FIG. 14illustrates the fifth example medical device800disposed behind a palatopharyngeus muscle900within an oral cavity990of a patient during an implantation procedure. A user has used forceps992to maintain a clearance994behind the palatopharyngeus muscle900while the first terminal end812of the medical device800has been passed through the clearance994. This represents an interim step in an implantation procedure.

Medical devices according to the invention are advantageously made from a pliable material, or a material that can be rendered pliable, to facilitate manipulation during implantation. A medical device according to a particular embodiment can be formed from any suitable material or materials, and using any suitable equipment and process or processes, and a skilled artisan will be able to select appropriate material(s), equipment, and process(es) for a medical device according to a particular embodiment based on various considerations, including the extent of any manipulation expected to be necessary or desirable during an implantation procedure.

A medical device according to the invention can be formed from a unitary section of material or as multiple sections of material secured to each other to form the medical device. For example, the inventors have determined that a medical device formed as a multilaminate construct, as described below, is considered advantageous.

Both synthetic and natural materials are considered suitable materials for forming medical devices according to embodiments of the invention. Examples of suitable synthetic materials include polymeric materials, such as polyethylene, polypropylene and other flexible polymeric materials. Examples of suitable natural materials include tissue and tissue-derived materials. The inventors have determined that medical devices formed of bioremodelable materials are particularly well-suited for medical devices according to embodiments of the invention at least because of the ability of such materials to remodel and become incorporated into adjacent tissues over time. These materials can provide a scaffold onto which cellular in-growth can occur, eventually allowing the material to remodel into a structure of host cells, which aids in the effectiveness of the medical device as a long-term support of the tissue being secured.

Particular advantage can be provided by medical devices that incorporate a remodelable collagenous material. Such remodelable collagenous materials, whether reconstituted or naturally-derived, can be provided, for example, by collagenous materials isolated from a warm-blooded vertebrate, especially a mammal. Such isolated collagenous material can be processed so as to have remodelable, angiogenic properties and promote cellular invasion and ingrowth. Remodelable materials may be used in this context to stimulate ingrowth of adjacent tissues into an implanted construct such that the remodelable material gradually breaks down and becomes replaced by new patient tissue so as to generate a new, remodeled tissue structure. Such materials are considered suitable for use in the main body, projections, and plug portions of medical devices. Suitable remodelable materials can be provided by collagenous extracellular matrix (ECM) materials possessing biotropic properties. For example, suitable collagenous materials include ECM materials such as those comprising submucosa, renal capsule membrane, dermal collagen, dura mater, pericardium, fascia lata, serosa, peritoneum or basement membrane layers, including liver basement membrane. Suitable submucosa materials for these purposes include, for instance, intestinal submucosa including small intestinal submucosa, stomach submucosa, urinary bladder submucosa, and uterine submucosa. Collagenous matrices comprising submucosa (potentially along with other associated tissues) useful in the present invention can be obtained by harvesting such tissue sources and delaminating the submucosa-containing matrix from smooth muscle layers, mucosal layers, and/or other layers occurring in the tissue source. For additional information as to some of the materials useful in the medical devices, and their isolation and treatment, reference can be made, for example, to U.S. Pat. Nos. 4,902,508, 5,554,389, 5,993,844, 6,206,931, and 6,099,567.

Remodelable ECM tissue materials harvested as intact sheets from a mammalian source and processed to remove cellular debris advantageously retain at least a portion of and potentially all of the native collagen microarchitecture of the source extracellular matrix. This matrix of collagen fibers provides a scaffold to facilitate and support tissue ingrowth, particularly in bioactive ECM implant materials, such as porcine small intestinal submucosa or SIS (Biodesign™, Cook Medical, Bloomington Ind.), that are processed to retain an effective level of growth factors and other bioactive constituents from the source tissue. In this regard, when a medical device incorporates this sort of material, cells will invade the remodelable material upon implantation eventually leading to the generation of a newly-remodeled, functional tissue structure.

Submucosa-containing or other ECM tissue used in medical devices according to embodiments of the invention is preferably highly purified, for example, as described in U.S. Pat. No. 6,206,931 to Cook et al. Thus, preferred ECM material will exhibit an endotoxin level of less than about 12 endotoxin units (EU) per gram, more preferably less than about 5 EU per gram, and most preferably less than about 1 EU per gram. As additional preferences, the submucosa or other ECM material may have a bioburden of less than about 1 colony forming units (CFU) per gram, more preferably less than about 0.5 CFU per gram. Fungus levels are desirably similarly low, for example less than about 1 CFU per gram, more preferably less than about 0.5 CFU per gram. Nucleic acid levels are preferably less than about 5 μg/mg, more preferably less than about 2 μg/mg, and virus levels are preferably less than about 50 plaque forming units (PFU) per gram, more preferably less than about 5 PFU per gram. These and additional properties of submucosa or other ECM tissue taught in U.S. Pat. No. 6,206,931 may be characteristic of any ECM tissue used in the inventive medical devices.

A typical layer thickness for an as-isolated submucosa or other ECM tissue layer used in the invention ranges from about 50 to about 250 microns when fully hydrated, more typically from about 50 to about 200 microns when fully hydrated, although isolated layers having other thicknesses may also be obtained and used. These layer thicknesses may vary with the type and age of the animal used as the tissue source. As well, these layer thicknesses may vary with the source of the tissue obtained from the animal source. In a dry state, a typical layer thickness for an as-isolated submucosa or other ECM tissue layer used in the invention ranges from about 10 to about 160 microns when fully dry, more typically from about 15 to about 130 microns when fully dry.

A medical device according to an embodiment of the invention can include one or more bioactive agents, such as in a coating or as an integrated component. Suitable bioactive agents may include one or more bioactive agents native to the source of an ECM tissue material used in the medical device. For example, a submucosa or other remodelable ECM tissue material may retain one or more growth factors such as but not limited to basic fibroblast growth factor (FGF-2), transforming growth factor beta (TGF-beta), epidermal growth factor (EGF), cartilage derived growth factor (CDGF), and/or platelet derived growth factor (PDGF). As well, submucosa or other ECM materials when used in the invention may retain other native bioactive agents such as but not limited to proteins, glycoproteins, proteoglycans, and glycosaminoglycans. For example, ECM materials may include heparin, heparin sulfate, hyaluronic acid, fibronectin, cytokines, and the like. Thus, generally speaking, a submucosa or other ECM material may retain one or more bioactive components that induce, directly or indirectly, a cellular response such as a change in cell morphology, proliferation, growth, protein or gene expression.

Submucosa-containing or other ECM materials used in a medical device according to an embodiment can be derived from any suitable organ or other tissue source, usually sources containing connective tissues. The ECM materials processed for use in the inventive medical devices will typically include abundant collagen, most commonly being constituted at least about 80% by weight collagen on a dry weight basis. Such naturally-derived ECM materials will for the most part include collagen fibers that are non-randomly oriented, for instance occurring as generally uniaxial or multi-axial but regularly oriented fibers. When processed to retain native bioactive factors, the ECM material can retain these factors interspersed as solids between, upon and/or within the collagen fibers. Particularly desirable naturally-derived ECM materials for use in the invention will include significant amounts of such interspersed, non-collagenous solids that are readily ascertainable under light microscopic examination with appropriate staining. Such non-collagenous solids can constitute a significant percentage of the dry weight of the ECM material in certain inventive embodiments, for example at least about 1%, at least about 3%, and at least about 5% by weight in various embodiments of the invention.

When used in medical devices according to embodiments of the invention, submucosa-containing or other ECM material may also exhibit an angiogenic character and thus be effective to induce angiogenesis in a host engrafted with the material. In this regard, angiogenesis is the process through which the body makes new blood vessels to generate increased blood supply to tissues. Thus, angiogenic materials, when contacted with host tissues, promote or encourage the formation of new blood vessels into the materials. Methods for measuring in vivo angiogenesis in response to biomaterial implantation have recently been developed. For example, one such method uses a subcutaneous implant model to determine the angiogenic character of a material. See, C. Heeschen et al., Nature Medicine (2001), No. 7, 833-839. When combined with a fluorescence microangiography technique, this model can provide both quantitative and qualitative measures of angiogenesis into biomaterials. C. Johnson et al., Circulation Research 94 (2004), No. 2, 262-268.

Further, in addition or as an alternative to the inclusion of such native bioactive components, non-native bioactive components such as those synthetically produced by recombinant technology or other methods (e.g., genetic material such as DNA), may be incorporated into an ECM material used in a medical device according to an embodiment of the invention. These non-native bioactive components may be naturally-derived or recombinantly produced proteins that correspond to those natively occurring in an ECM tissue, but perhaps of a different species. These non-native bioactive components may also be drug substances. Illustrative drug substances that may be added to materials include, for example, anti-clotting agents, e.g. heparin, antibiotics, anti-inflammatory agents, thrombus-promoting substances such as blood clotting factors, e.g., thrombin, fibrinogen, and the like, and anti-proliferative agents, e.g. taxol derivatives such as paclitaxel. Such non-native bioactive components can be incorporated into and/or onto ECM material in any suitable manner, for example, by surface treatment (e.g., spraying) and/or impregnation (e.g., soaking), to name a few. Also, these substances may be applied to the ECM material in a premanufacturing step, immediately prior to the procedure (e.g., by soaking the material in a solution containing a suitable antibiotic such as cefazolin), or during or after engraftment of the material in the patient.

Medical devices according to embodiments of the invention can incorporate xenograft material (i.e., cross-species material, such as tissue material from a non-human donor to a human recipient), allograft material (i.e., interspecies material, with tissue material from a donor of the same species as the recipient), and/or autograft material (i.e., where the donor and the recipient are the same individual). Further, any exogenous bioactive substances incorporated into an ECM material may be from the same species of animal from which the ECM material was derived (e.g. autologous or allogeneic relative to the ECM material) or may be from a different species from the ECM material source (xenogeneic relative to the ECM material). In certain embodiments, ECM material will be xenogeneic relative to the patient receiving the graft, and any added exogenous material(s) will be from the same species (e.g. autologous or allogeneic) as the patient receiving the graft. Illustratively, human patients may be treated with xenogeneic ECM materials (e.g. porcine-, bovine- or ovine-derived) that have been modified with exogenous human material(s) as described herein, those exogenous materials being naturally derived and/or recombinantly produced.

The inventors have determined that SIS is particularly well-suited for use in medical devices according to the embodiments of the invention at least because of its well-characterized nature and ready availability. Furthermore, the inventors have determined that vacuum-pressed SIS provides a particularly advantageous material from which to form medical devices according to embodiments of the invention. Lyophilized SIS can also be used, and may be advantageous for medical devices for which a relatively quicker remodeling time is desired. Radiopaque SIS can also be used, and may be advantageous for medical devices for which enhanced visualization characteristics are desired.

The inventors have determined that a medical devices formed of multiple layers laminated together provides a particularly advantageous structure. Thus, the main body can comprise a multilaminate construct. In these embodiments, any suitable number of layers can be used, and a skilled artisan will be able to select an appropriate number of layers for a particular medical device based on various considerations, including the intended use of the medical device and nature of the tissue intended to be supported by the medical device. The inventors have determined that a medical device formed of between 4 and 15 layers of an ECM material, such as SIS, provides a particularly advantageous structure for medical devices according to embodiments of the invention. A medical device formed of between 8 and 12 layers of an ECM material, such as SIS, is also considered particularly advantageous. A medical device formed of 12 layers of an ECM material, such as SIS, is also considered particularly advantageous. A medical device formed of up to 60 layers of an ECM material, such as SIS, is also considered particularly advantageous. In these embodiments, the layers can be assembled together in any suitable manner and using any suitable technique or process. For multilaminate SIS constructs, the inventors have determined that vacuum-pressing of multiple layers of SIS provides a suitable laminate structure for use as a medical device as described herein. The layers in the multilaminate construct can be vacuum-pressed prior to assembly into the multilaminate construct. Alternatively, the multilaminate construct can be vacuum-pressed after assembly of the layers. In these embodiments, the layers are advantageously non-vacuum pressed prior to assembly into the multilaminate construct. Also alternatively, the layers can be vacuum-pressed prior to assembly and the assembly can be vacuum-pressed after assembly. The inventors have determined that a medical device formed of about 12 layers of SIS, vacuum-pressed only after layer assembly, provides a medical device having desirable durability, profile, handling, and performance characteristics. The inventors have determined that use of vacuum-pressed layers of SIS can also provide desirable characteristics. When using vacuum-pressed layers of an ECM material, such as SIS, any suitable number of vacuum-pressed layers can be used. The inventors have determined that a medical device formed of between 4 and 60 vacuum-pressed layers provides a particularly advantageous structure for medical devices according to embodiments of the invention. A medical device formed of between 10 and 50 vacuum-pressed layers is also considered particularly advantageous. A medical device formed of between 10 and 30 vacuum-pressed layers is also considered particularly advantageous. A medical device formed of between 10 and 20 vacuum-pressed layers is also considered particularly advantageous.

A hybrid structure in which a mesh is embedded inside an SIS or other composition or between layers of SIS or of other material is also considered suitable. For example, a polymeric mesh, such as a mesh formed of polypropylene, can be disposed between layers of SIS during formation of a medical device according to an embodiment. In these embodiments, the polymeric mesh will remain in the body following completion of remodeling by the SIS, which may enhance the overall anchoring of the supported tissue over time. A bioabsorbable mesh, such as a mesh formed of polyglycolic acid or other bioabsorbable material, can also be included in the medical device in this manner and may be advantageous where supplemental support is desired that lasts beyond the remodeling time for the SIS, but that does not have the permanency associated with a polypropylene or other polymeric mesh. Examples of suitable structural arrangements of polymer and remodelable layers can be found in United States Patent Application Publication No. 2011/0166673 to Patel et al., for QUILTED IMPLANTABLE GRAFT, the entire contents of which are hereby incorporated into this disclosure.

Medical devices according to an embodiment, or portions thereof, can also be coated with particular materials to provide a desired property or properties. For example, the inventors have determined that coating a medical device with poly(lactic-co-glycolic acid) (PLGA) provides a desirable stiffening effect to the implant while also providing an agent that promotes an inflammatory response in tissue within which the medical device has been placed. In medical devices that comprise a multilaminate construct, as describe above, a coating can be applied between layers during fabrication. For example, PLGA can be applied to or embedded within one, two, a plurality of, or all of the layers when making a medical device that comprise a multilaminate construct.

FIG. 15is a flowchart illustration of an example method2000of treating obstructive sleep apnea. An initial step2010comprises creating a mucosal incision in the arch of the posterior tonsillar pillar to expose the palatopharyngeus muscle. Another step2012comprises isolating the palatopharyngeus muscle to create a clearance behind the palatopharyngeus muscle. It is considered advantageous to create a clearance of between about 0.50 cm and about 1 cm behind the palatopharyngeus muscle. Creation of a clearance of about 0.75 cm behind the palatopharyngeus muscle is considered particularly advantageous for this step. Another step2014comprises inserting one end of a medical device according to an embodiment into the clearance created in step2012. Another step2016comprises wrapping the medical device around the palatopharyngeus muscle. Another step2018comprises passing one end of the medical device through the slot of the medical device. Another step2020comprises pulling one end of the medical device to create a snug fit of the medical device around the palatopharyngeus muscle. Another step2022comprises placing the end of the medical device that was passed through the slot in step2018into the palatoglossus muscle toward the hammulus. Another step2024comprises passing an anchor member, such as a suture, through a passageway through the main body of the medical device. Another step2026comprises securing the anchor member to tissue to lateralize the palatopharyngeus muscle.

FIG. 16is a flowchart illustration of an example method3000of treating obstructive sleep apnea. An initial step3010comprises palpating the soft palate to ensure no evidence of a submucosal cleft is found. Another step3012comprises creating a mucosal incision in the arch of the posterior tonsillar pillar to expose the palatopharyngeus muscle. Another step3014comprises isolating the palatopharyngeus muscle to create a clearance behind the palatopharyngeus muscle. Another step3016comprises inserting one end of a medical device according to an embodiment into to the clearance that was created in step3014. Another step3018comprises wrapping the medical device around the palatopharyngeus muscle. Another step3020comprises passing one end of the medical device through the slot of the medical device. Another step3022comprises pulling one end of the medical device to create a snug fit of the medical device around the palatopharyngeus muscle. Another step3024comprises passing an anchor member, such as a suture, through a passageway through the main body of the medical device near the narrow end of the medical device. Another step3026comprises advancing the narrow end of the medical device deep to the palatoglossus muscle toward the hammulus. Another step3028comprises retrieving a needle from the mucosa overlying the hammulus. Another step3030comprises reintroducing the needle into the mucosa and tunneling medially in the submucosa toward the mucosal incision. Another step3032comprises securing the anchor member to tissue to lateralize the palatopharyngeus muscle. Another step3034comprises closing the incision with a suitable closure device, such as one or more sutures. The method3000can include repetition of all steps on an opposite side of the oral cavity of a patient to implant a second medical device if desired. Additionally, an optional step of injecting long acting anesthetic into the soft tissue as required can be included. In one alternative method, an additional step comprises creating a second mucosal incision to better visualize the anchor site. In this method, the step3032of securing the anchor member can be performed such that the anchor is secured at that second mucosal incision. To complete this method, the step3034of closing the incision comprises closing both incisions with a suitable closure device, such as sutures.

Each ofFIGS. 17 through 20illustrates a medical device4000according to an embodiment within an oral cavity4090of a patient during a stage of an implantation procedure conducted according to a method of treating obstructive sleep apnea in accordance with an embodiment. For example, inFIG. 17, one end4010of the medical device4000has been inserted into a clearance4994created behind the palatopharyngeus muscle4900. InFIG. 18, the medical device4000has been wrapped around the palatopharyngeus muscle4900and one end4010of the medical device4000has been passed through the slot4012of the medical device4000. InFIG. 19, the end4010of the medical device4000that was passed through the slot4012has been placed into the palatoglossus muscle toward the hammulus.FIG. 20illustrates the oral cavity4090after completion of the procedure in which the medical device4000and a second medical device5000were implanted.

Those with ordinary skill in the art will appreciate that various modifications and alternatives for the described and illustrated embodiments can be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are intended to be illustrative only and not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof.