US 20080078412 A1
A patient's obstructive sleep apnea is treated by identifying a patient with sleep apnea attributable at least in part to movement of a base of a tongue of the patient toward a pharyngeal wall of the patient. The tongue is stiffened by an implant sized to be placed within the tongue. A distal portion of the implant is sized to extend within the tongue from a first end near a mandibular-geniohyoid interface to a second end near a base of the tongue. A proximal portion is attached to the first end and adapted to be secured to a jaw bone of the patient following a period of healing after placement of the implant in the tongue.
1. A method for treating obstructive sleep apnea comprising:
identifying a patient with sleep apnea attributable at least in part to movement of a base of a tongue of said patient toward a pharyngeal wall of said patient;
identifying a region in the tongue extending from a mandibular-geniohyoid interface to the base of the tongue;
stiffening a tissue of the tongue throughout the identified region;
wherein said stiffening includes placing an implant of fibrosis-inducing material within the tongue with the implant extending within said region with the material selected to induce formation of fibrosis along said region; and
attaching a proximal end of the implant to a jaw bone of the patient.
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11. An apparatus treating obstructive sleep apnea of a patient, said apparatus comprising:
an implant sized to be placed within a tongue of the patient;
the implant having a proximal portion and a distal portion;
the distal portion sized to be implanted in the tongue near a base of the tongue;
the distal portion selected of a material for creating a fibrotic response following implantation in the tongue;
the proximal portion attached to the first end and adapted to be secured to a jaw bone of the patient.
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The present application is a continuation-in-part of U.S. patent application Ser. No. 11/542,455, filed Oct. 3, 2006, titled “Tongue Implant for Sleep Apnea”, which application is hereby incorporated by reference in its entirety.
1. Field of the Invention
This invention pertains to a method for treating a condition of an upper airway of a patient. More particularly, this invention is directed to a method for treating obstructive sleep apnea by stiffening a tongue of a patient.
2. Description of the Prior Art
Upper airway conditions such as obstructive sleep apnea (“OSA”) and snoring have received a great deal of attention. These conditions have recognized sociological and health implications for both the patient and the patient's bed partner.
Numerous attempts have been made towards treating OSA and snoring. These include placing implants in either the tissue of the soft palate or the pharyngeal airway as disclosed in commonly assigned U.S. Pat. No. 6,250,307 to Conrad et al. dated Jun. 26, 2003, U.S. Pat. No. 6,523,542 to Metzger et al. dated Feb. 25, 2003 and U.S. Pat. No. 6,431,174 to Knudson et al. dated Aug. 13, 2002. Further, U.S. Pat. No. 6,601,584 to Knudson et al. dated Aug. 5, 2003 teaches a contracting implant for placement in the soft palate of the patient.
Another prior art technique for treating OSA or snoring is disclosed in U.S. Pat. No. 5,988,171 to Sohn et al. dated Nov. 23, 1999. In the '171 patent, a cord (e.g., a suture material) (element 32 in FIG. 6 of the '171 patent) is placed surrounding a base of the tongue and secured to the jaw by reason at an attachment member (element 20 in FIG. 6 of the '171 patent). In the method of the '171 patent, the member 32 can be shortened to draw the base of the tongue toward the jaw and thereby move the tissue of the base of the tongue away from the opposing tissue of the pharyngeal airway. However, this procedure is often uncomfortable. This procedure, referred to as tongue suspension, is also described in Miller et al., “Role of the tongue base suspension suture with The Repose System bone screw in the multilevel surgical management of obstructive sleep apnea”, Otolaryngol. Head Neck Surg., Vol. 126, pp. 392-398 (2002).
Another technique includes debulking tissue by applying radio frequency ablation to either the tongue base or of the soft palate to debulk the tissue of the tongue or palate, respectively. This technique is illustrated in U.S. Pat. No. 5,843,021 to Edwards et al. dated Dec. 1, 1998. RF tongue base reduction procedures are described in Powell et al., “Radiofrequency tongue base reduction in sleep-disordered breathing: A pilot study”, Otolaryngol. Head Neck Surg., Vol. 120, pp. 656-664 (1999) and Powell et al., “Radiofrequency Volumetric Reduction of the Tongue—A Porcine Pilot Study for the Treatment of Obstructive Sleep Apnea Syndrome”, Chest, Vol. 111, pp. 1348-1355 (1997).
A surgical hyoid expansion to treat OSA is disclosed in U.S. Pat. No. 6,161,541 to Woodson dated Dec. 19, 2000. Other tongue treatments for OSA include stimulation of the hypoglossal nerve. This procedure is described in Eisle et al., “Direct Hypoglossal Nerve Stimulation in Obstructive Sleep Apnea”, Arch. Otolaryngol. Head Neck Surg., Vol. 123, pp. 57-61 (1997).
Commonly assigned U.S. patent applications Publication Nos. US 2005/0092332 A1 and US 2005/0092334 A1 (both published May 5, 2005) describe tongue-based treatments to treat obstructive sleep apnea. U.S. patent application Ser. Nos. 11/107,160 and 11/107,161 (both filed Apr. 15, 2005 and assigned to the assignee of the present invention) describe various implants for a tongue to treat obstructive sleep apnea.
European Patent EP 1,039,859 B1 granted Dec. 3, 2003 describes a brace placed in the tongue. German Patent No. 19 920 114 describes struts in pharyngeal wall. U.S. patent applications Publication Nos. US 2005/0126563 A1 published Jun. 16, 2005 and US 2005/0199248 A1 published Sep. 15, 2005 describe stents in an airway. U.S. patent applications Publication Nos. US 2004/0139975 published Jul. 22, 2004 and US 2004/0149290 published Aug. 5, 2005 (both assigned to Apneon Inc.) describe struts or magnets in the tongue.
According to a preferred embodiment, obstructive sleep apnea of a patient is treated by identifying a patient with sleep apnea attributable at least in part to movement of a base of a tongue of said patient toward a pharyngeal wall of said patient. The method includes identifying a region in the tongue extending from a mandibular-geniohyoid interface to the base of the tongue and stiffening a tissue of the tongue throughout the identified region. The region is stiffened by an implant sized to be placed within a tongue of the patient. A distal portion of the implant is sized to extend within the tongue from a first end near a mandibular-geniohyoid interface to a second end near a base of the tongue. The proximal portion is attached to the first end and adapted to be secured to a jaw bone of the patient following a period of healing after placement of the implant in the tongue. In a most preferred embodiment, at least a portion of the proximal portion is formed of an elastomeric material for the implant to stretch and contract in response to movement of the tongue during speech and swallowing.
With reference now to the various drawing figures in which identical elements are numbered identically throughout, a description of the preferred embodiment of the present invention will now be provided.
1. Disclosure of Parent Application
A hyoid bone HB resides near the bottom of the tongue near an epiglottis E. A mandible or jaw bone JB is at the front of the tongue T. The geniohyoid muscle GH extends between the jaw bone JB and the hyoid bone HB at the bottom of the tongue T.
The lines A of
When reclining during sleep, the tongue base TB may, in response to gravity or airflow, drop down in closer approximation to the pharyngeal wall PW. During sleep, the muscles of the tongue T (principally the genioglossus muscle GG) can stretch permitting the tongue T to fall back toward the pharyngeal wall PW.
The present invention is directed towards method and apparatus for stiffening the muscles of the tongue T in a manner to preclude the tongue T from falling toward the pharyngeal wall PW while avoiding interference with normal functions of the tongue T during speech and eating.
The implant 10 is sized to be received within the tongue T with the proximal end 12 positioned in a region of the tongue T adjacent the interface of the jaw JB and geniohyoid muscle GH. The height of the proximal end 12 (illustrated as HP in
The material of the implant 10 is selected to produce a fibrotic response from the tissue of the tongue T following implantation of the implant 10 within the tongue T. The specific materials and construction may be varied to alter the degree of fibrotic response resulting from such implantation. By way of non-limiting example, the material of the implant 10 may be a knit or woven polyester or polypropylene material known to result in a fibrosis formation following implantation.
In use, the blades 28, 30 are collapsed so that they are in parallel alignment as shown in
When the tool 20 is in the position of
Following formation of the pocket, an insertion tool 40 is provided as illustrated in
With the blades 44, 46 in parallel alignment as shown in
As mentioned, it is desired that the proximal end 12 of the implant 10 be as positioned as close as possible to the jaw bone JB in the region of the geniohyoid muscle GH. If necessary, the surgeon can form additional incisions through the tongue T to pull the proximal end 12 into the geniohyoid muscle GH in close proximity to the jaw bone JB.
Following implantation, a fibrotic capsule FC forms around the material of the implant 10. The capsule FC is illustrated in
At the juncture of the geniohyoid muscle GH and the jaw bone JB (referred to herein as the “mandibular-geniohyoid interface”, muscle fibers of the tongue are tendon-like. By “tendon-like”, it is meant the muscle fibers are less susceptible to stretching than the remainder of the length of the fibers. Since the fibrotic capsule FC and the proximal end 12 of the implant 10 originate in this region, a substantially non-stretchable region is formed in the tongue T by reason of the fibrotic capsule FC and the implant 10.
In the absence of an implant 10, substantially the entire length of muscle fibers from the jaw bone JB to the tongue base TB can stretch during sleep resulting in the tongue base TB falling against the soft palate SP or pharyngeal wall PW during sleep.
With the implant 10 extending from the jaw bone JB to the tongue base TB, the muscle fibers in contact with the implant 10 and resulting fibrotic capsule FC are much less susceptible to stretching.
Use of two implants 10, 10′ (
This volume V is illustrated in
The base of the conical volume is at the tongue base TB near the surface of the tongue and covering the portion of the tongue base TB opposing the pharyngeal wall PW between the epiglottis E and the training end TE of the soft palate SP. The volume V extends between the lateral extremities of the tongue base TB. Treatment of the entire volume can be accomplished by multiple implants 10 placed as described above. Alternatively, the volume V can be injected with any fibrosis-inducing agent (e.g., microbeads) throughout the volume V.
Ideally, the implant 10 will contract and expand with the muscle as it heals. Otherwise, a capsule surrounding the implant 10 will form as muscle slides over the implant 10. This property is enabled by a combination of factors: the restoring force of the implant 10, the friction against the tissue and attachments if any at either end. The mesh material of the implant 10 aids in achieving these objectives. The goal is to have an appropriate amount of spring tension/expansion and wall friction/in-growth such that the implant 10 contracts and expands with tissue. It is desirable to avoid an implant so stiff as to overly contract the muscle. This may cause the distal end of the implant to slide more proximal. As the scar forms and contracts, the implant contracts more permanently with the scar. This suggests the restoring force decreases over time. Biodegradable fibers suitable for this purpose or biodegradable coatings on the fibers themselves (which adhere the fibers together) may be used. The elastic properties of the implant should are approximately between 5 kPa to 50 kPa. The frictional force should be approximately 2N to 4N. The patient's physiology and the size of the implant affect the range for these values.
The implant 10″ may be placed with a proximal end 12″ at the mandibular-geniohyoid interface and with a distal end 14″ at the tongue base TB.
The insertion tool for the tube shaped implants 10″ may be much like the insertion tool described in U.S. patent application Publication No. 2005/0154412 A1 (incorporated herein by reference) which describes a tool for placing a solid braided implant such as that marketed by assignee of the present application (Restore Medical Inc., St. Paul, Minn., USA) under the trademark “Pillar”. The tool may be modified to replace the needle of the tool with a rod received within the implant 10″ through the proximal end 12″. The rod may extend to the distal tip 14″ of the implant 10″. Retracting the rod leaves the implant 10″ in desired position in the tongue T.
In the foregoing example, no stiffening treatment is made in the tongue T in the upper region of the tongue T. Generally defined herein as the region of the tongue T above and forward of a line from the jaw bone JB to the trailing end of the hard palate HP, this region of the tongue T is active in speech and swallowing. Since no treatment is made in this region, these functions are not impaired.
2. Additional Disclosure of the Present Application
The proximal portion 120 is an elastomeric material such as silicone or the like. The silicone is molded over a first end 111 of the distal portion 110 to define an over-molded portion 170 (
The silicone proximal portion 120 includes a most proximal reinforced region 130. Region 130 may have reinforcing fibers such as polyester to reinforce the strength of the silicone in the region 130. The region 130 includes a plurality of holes 140 spaced along the length of the region 130 for receiving an attachment screw 150 (shown only in
In use of the implant 100, the incision formation tool 40 forms an incision within the tongue T as previously described. With the blades 44, 46 in the closed position, the blades are inserted through the slit 115 into the interior of the distal portion 110 as illustrated in
After a period of time (for example, about 4 weeks), a healing process occurs and fibrosis results attaching the tissue of the tongue T to the mesh material of the distal portion 110. Following such healing, an incision (not shown) may be made into the tongue T from beneath the chin of the patient. The physician grabs the proximal portion 120 and retracts it relative to the base of the tongue TB. This causes a retraction of the tongue base TB from the pharyngeal wall.
With the tongue base TB so retracted, the proximal portion 120 is attached to the jaw bone JB by passing screw 150 through a select one of the holes 140 and into the jaw bone JB. The incision can then be closed with the apparatus 100 remaining in the position shown in
During normal tongue functions such as speech and swallowing, the tongue T may be urged to move away from the jaw bone JB. This movement is facilitated by the elastic material of the proximal portion 120 so as not to interfere with normal speech and swallowing functions of the tongue.
It has been shown how the present invention has been obtained in a preferred embodiment. Modifications and equivalents of the disclosed concepts are intended to be included within the scope of the claims which are appended hereto.