Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
  • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
  • A61B18/14—Probes or electrodes therefor
  • A61B18/1477—Needle-like probes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
  • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
  • A61B18/14—Probes or electrodes therefor
  • A61B18/1485—Probes or electrodes therefor having a short rigid shaft for accessing the inner body through natural openings
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
  • A61B18/1815—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using microwaves
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/40—Applying electric fields by inductive or capacitive coupling ; Applying radio-frequency signals
  • A61N1/403—Applying electric fields by inductive or capacitive coupling ; Applying radio-frequency signals for thermotherapy, e.g. hyperthermia
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/02—Radiation therapy using microwaves
  • A61N5/04—Radiators for near-field treatment
  • A61N5/045—Radiators for near-field treatment specially adapted for treatment inside the body
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/24—Surgical instruments, devices or methods, e.g. tourniquets for use in the oral cavity, larynx, bronchial passages or nose; Tongue scrapers
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B2017/00017—Electrical control of surgical instruments
  • A61B2017/00022—Sensing or detecting at the treatment site
  • A61B2017/00026—Conductivity or impedance, e.g. of tissue
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B2018/00636—Sensing and controlling the application of energy
  • A61B2018/00666—Sensing and controlling the application of energy using a threshold value
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B2018/00636—Sensing and controlling the application of energy
  • A61B2018/00666—Sensing and controlling the application of energy using a threshold value
  • A61B2018/00678—Sensing and controlling the application of energy using a threshold value upper
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B2018/00636—Sensing and controlling the application of energy
  • A61B2018/00696—Controlled or regulated parameters
  • A61B2018/00702—Power or energy
  • A61B2018/00708—Power or energy switching the power on or off
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B2018/00636—Sensing and controlling the application of energy
  • A61B2018/00773—Sensed parameters
  • A61B2018/00875—Resistance or impedance
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M25/00—Catheters; Hollow probes
  • A61M25/0067—Catheters; Hollow probes characterised by the distal end, e.g. tips
  • A61M25/0082—Catheter tip comprising a tool
  • A61M2025/0096—Catheter tip comprising a tool being laterally outward extensions or tools, e.g. hooks or fibres
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/02—Radiation therapy using microwaves
  • A61N5/04—Radiators for near-field treatment

Definitions

• This invention relates to a method for maintaining upper airway patency in human patients, and more particularly to a method which utilizes electromagnetic energy to debulk selected sections ofthe tongue and/or lingual tonsil without damaging the hypoglossal nerve.
• Sleep-apnea syndrome is a medical condition characterized by daytime hypersomnomulence, morning arm aches, intellectual deterioration, cardiac arrhythmias, snoring and thrashing during sleep. It is caused by frequent episodes of apnea during the patient's sleep.
• the syndrome is classically subdivided into two types.
• One type termed "central sleep apnea syndrome" is characterized by repeated loss of respiratory effort.
• the second type termed obstructive sleep apnea syndrome
• obstructive sleep apnea syndrome is characterized by repeated apneic episodes during sleep resulting from obstruction ofthe patient's upper airway or that portion ofthe patient's respiratory tract which is cephalad to, and does not include, the larynx.
• Treatment thus far includes various medical, surgical and physical measures. Medical measures include the use of medications such as protriptyline, medroxyprogesterone, acetazolamide, theophylline, nicotine and other medications in addition to avoidance of central nervous system depressants such as sedatives or alcohol. The medical measures above are sometimes helpful but are rarely completely effective. Further, the medications frequently have undesirable side effects.
• Surgical interventions have included uvulopalatopharyngoplasty, tonsillectomy, surgery to correct severe retrognathia and tracheostomy.
• the jaw is dislodged and pulled forward, in order to gain access to the base ofthe tongue.
• Phrenic nerve or diaphragmatic pacing includes the use of electrical stimulation to regulate and control the patient's diaphragm which is innervated bilaterally by the phrenic nerves to assist or support ventilation. This pacing is disclosed in Direct Diaphragm Stimulation by J. Mugica et al. PACE vol.
• Laryngeal Pacemaker by F. Kaneko et al. from Trans Am Soc Artif Intern Organs 1985 senses volume displaced by the lungs and stimulates the appropriate nerve to open the patient's glottis to treat dyspnea.
• This apparatus is not effective for treatment of sleep apnea.
• the apparatus produces a signal proportional in the displaced air volume ofthe lungs and thereby the signal produced is too late to be used as an indicator for the treatment of sleep apnea. There is often no displaced air volume in sleep apnea due to obstruction.
• an object ofthe invention is to provide a method and apparatus for cosmetically remodeling a tongue.
• Another object ofthe invention is to provide a method and apparatus for cosmetically remodeling a tongue without damaging a hypoglossal nerve ofthe tongue.
• Still another object ofthe invention is to provide a method and apparatus for cosmetically remodeling a tongue with reduced swelling ofthe tongue.
• a further object ofthe invention is to provide a method and apparatus for cosmetically remodeling a tongue by applying ablative energy to a selected site in an interior ofthe tongue without damaging a hypoglossal nerve ofthe tongue.
• Still a further object ofthe invention is to provide a method and apparatus for cosmetically remodeling a tongue by applying an ablative agent to a selected site in an interior ofthe tongue without damaging a hypoglossal nerve ofthe tongue.
• Another object ofthe invention is to provide a method and apparatus for cosmetically remodeling the tongue while cooling a surface ofthe tongue.
• a cooling element includes a cooling medium inlet conduit and a cooling medium exit conduit, both extending through an interior ofthe catheter forming at least a partial cooled catheter tissue interface surface.
• the electrode electromagnetic energy delivery surface is thermally isolated from the cooling element.
• An electrode advancement and retraction device is at least partially positioned in the interior ofthe catheter.
• a cable is coupled to the electrode.
• a method for cosmetically remodeling a body structure provides an ablation apparatus.
• the ablation apparatus includes a catheter with a catheter tissue interface surface, an electrode at least partially positioned in an interior ofthe catheter and advanceable and retractable to and from the catheter into an interior of a body structure, and a means for cooling the catheter tissue interface surface.
• the electrode is advanced from the interior ofthe catheter through a body structure external surface into the interior ofthe body structure. Sufficient electromagnetic energy is delivered from the electrode into the interior ofthe body structure to ablate a portion ofthe interior ofthe body structure.
• the catheter tissue interface surface is cooled sufficiently to reduce a swelling ofthe body structure external surface.
• the electrode is retracted from the interior of the body structure.
• the catheter tissue interface surface can be cooled to a temperature of 10 to 30 degrees C.
• the electrode may be hollow and coupled to an infusion medium source.
• An insulation sleeve can be positioned in a surrounding relationship to at least a portion of an exterior surface ofthe electrode.
• One or more electrodes may be introduced through the catheter.
• one or more sensors can be positioned at various locations ofthe ablation apparatus including at a distal end ofthe electrode, at an exterior surface ofthe electrode, at a distal end ofthe insulation sleeve or at the catheter tissue interface surface.
• a variety of different electromagnetic energy sources can be coupled to the electrode including but not limited to RF and microwave sources.
• the body structure is the tongue.
• the electrode is introduced through the tongue's ventral surface, dorsal surface or the dorsum surface. Sufficient cooling is provided to reduce a swelling of the exterior surface of a tongue following delivery of electromagnetic energy to an interior of the tongue by at least fifty percent.
• BRTEF DESCRTPTTON OF THE FTGTJRES Figure 1 is a cross-sectional view of an ablation apparatus used with the methods of the present invention.
• Figure 2 is cross-sectional view illustrating the catheter and connector of the ablation apparatus shown in Figure 1.
• Figure 3 is a perspective view ofthe connector illustrated in Figure 1.
• Figure 4 is a perspective view of a needle electrode associated with the ablation apparatus illustrated in Figure 1.
• Figure 5 is a perspective view of a flexible needle electrode utilized with the methods ofthe present invention.
• Figure 6 illustrates the creation of ablation zones with the ablation apparatus shown in Figure 1.
• Figure 7 is a cross-sectional view ofthe tongue with the mouth closed.
• Figure 8 is a cross-sectional view ofthe tongue with the mouth open.
• Figure 9 is a perspective view ofthe tongue.
• Figure 10 is a perspective view ofthe dorsum ofthe tongue.
• Figure 11 is a cross-sectional view ofthe tongue.
• Figure 12 is a cross-sectional view ofthe tongue illustrating the location ofthe hypoglossal nerves and the creation of an ablation zone.
• Figure 13 is a cross-sectional view ofthe tongue illustrating a plurality of ablation zones.
• Figure 14 is a perspective view ofthe ventral surface ofthe tongue.
• Figure 15 is a cross-sectional view ofthe tongue.
• Figure 16 is a block diagram illustrating an analog amplifier, analog multiplexer and microprocessor used with the feedback control system.
• Figure 17 is a block diagram of a temperature/impedance feedback system that can be used to control cooling medium flow rate through the catheter of Figure 1.
• Figure 18 is a block diagram of a temperature/impedance feedback system that can be used to control cooling medium flow rate through the catheter of Figure 1.
• Figure 19 is a three dimensional graph illustrating the percent shrinkage of the tongue following RF ablation.
• Figure 20 is a graph illustrating two-dimensional shrinkage of bovine tongue tissue with RF ablation.
• Figure 21 is a graph illustrating three-dimensional shrinkage of bovine tongue tissue due to RF ablation.
• Figure 22 is a graph illustrating percent volume change in a tongue following RF ablation.
• a method for cosmetically remodeling and debulking the tongue, uvula, soft palate, lingual tonsil and/or adenoids provides an ablation apparatus including a source of electromagnetic energy and one or more electromagnetic energy delivery electrodes coupled to the electromagnetic energy source. At least one electrode is advanced into an interior ofthe tongue. Sufficient electromagnetic energy is delivered from the electrode to debulk a section ofthe tongue without damaging the hypoglossal nerve. The electrode is then removed from the interior of the tongue.
• a method for treating airway obstructions is achieved by debulking the tongue without damaging the hypoglossal nerve.
• the electrode can be introduced into the tongue from the tongue's tip, ventral surface, dorsum, underneath the tongue, along the tongue's midline, or in certain instances through the chin area.
• the tongue is ablated (debulked) without damaging the hypoglossal nerves, resulting in a remodeling ofthe tongue and a cosmetic change. This is achieved by positioning the electrodes far enough away from the hypoglossal nerves so that during the delivery of electromagnetic energy to the tongue, the hypoglossal nerves are not damaged.
• Another method for treating airway obstructions is achieved by debulking the lingual tonsil without damaging the hypoglossal nerve. These methods are used to treat sleep apnea.
• Ablation apparatus 10 for cosmetically remodeling and debulking the tongue, lingual tonsils, uvula, soft palate and/or adenoids is illustrated.
• Ablation apparatus 10 can be positioned so that one or more energy delivery devices or electrodes 12 are introduced into an interior of the tongue through the tongue.
• Ablation apparatus 10 may include atraumatic intubation with or without visualization, provide for the delivery of oxygen or anesthetics, and can be capable of suctioning blood or other secretions. It will be appreciated that ablation apparatus 10 is used to treat a variety of different obstructions in the body where passage of gas is restricted.
• One embodiment is the treatment of sleep apnea using electrodes 12 to ablate (cell necrosis) selected portions ofthe tongue, lingual tonsils and/or adenoids by the use of resistive heating, RF, microwave, ultrasound and liquid thermal jet.
• the preferred energy source is an RF source.
• ablation apparatus 10 can be used to ablate targeted masses including but not limited to the tongue, tonsils, turbinates, soft palate tissues, hard tissue and mucosal tissue.
• ablation apparatus 10 is used to debulk the tongue in order to increase the cross-sectional area ofthe air passageway.
• a disinfectant medium introduction member introduces a disinfectant medium in the oral cavity in order to reduce infection of the ablated body member.
• a presurgical evaluation may be performed including a physical examination, fiberoptic pharyngoscopy, cephalometric analysis and polygraphic monitoring.
• the physical examination emphasizes the evaluation ofthe head and neck. It also includes a close examination ofthe nasal cavity to identify obstructing deformities ofthe septum and turbinate; oropharyngeal obstruction from a long, redundant soft palate or hypertrophic tonsils; and hypopharyngeal obstruction from a prominent base ofthe tongue.
• Debulking apparatus 10 includes a catheter 14, an optional handle 16 and one or more electrodes 12 extending from different ports 18 formed along a longitudinal surface of catheter 14, or from a distal end of electrode 12.
• Catheter 14 can be a handpiece.
• An advancement device 20 may be provided.
• Advancement device 20 can include guide tracks or tubes 23 positioned in the interior of catheter 14. Electrodes 12 may be positioned in guide tracks 23 and advanced from guide tracks into the interior ofthe tongue.
• Ablation or debulking apparatus 10 includes a catheter 14, an optional handle 16 and one or more ablation source delivery device 12 extending from different ports 18 formed along a longitudinal surface of catheter 14, or from a distal portion of ablation source delivery device 12
• Catheter 14 can be a handpiece.
• Ablation source delivery device advancement device 20, also known as advancement device 20 may be provided.
• Ablation source delivery device advancement device 20 can include guide tracks or tubes 23 positioned in the interior of catheter 14.
• Ablation source delivery device 12 may be positioned in guide tracks 23 and advanced from the guide tracks into the interior ofthe tongue. Cabling is coupled to ablation source delivery device 12. Ablation source delivery device 12 may be least partially positioned in an interior of catheter 14. In one embodiment, ablation source delivery device 12 is advanced and retracted through a port 18 formed in an exterior surface of catheter 14. Ablation source delivery device advancement and retraction device 20 advances ablation source delivery device 12 out of catheter 14, into an interior of a body structure and can also provide a retraction of ablation source delivery device 12 from the interior ofthe body structure. Although the body structure can be any number of different structures, the body structure will hereafter be referred to as the tongue. Ablation source delivery device 12 pierce an exterior surface of the tongue and are directed to an interior region ofthe tongue.
• Ablation source delivery device 12 can be a hollow structure that is, (i) adapted to deliver different chemicals to a selected tongue interior ablation site (for chemical ablation) (ii) deliver alcohol or other liquids or semi-liquids to achieve ablation as well as a variety of different infusion mediums, including but not limited to saline, chemotherapy and the like. Different modalities can be combined to achieved a desired ablation including but not limited to RF and chemotherapy, chemical and chemotherapy.
• Ablation source delivery device 12 may have a limited travel distance in the tongue.
• an insulation sleeve that is in a surrounding relationship to an exterior of an electrode.
• Other devices can include a structure located on ablation source delivery device 12 which limits their advancement, or a structure coupled to a catheter which limits the advancement of ablation source delivery devices 12, such as a stop and the like.
• One suitable fluid is an electrolytic solution.
• a cooled electrolytic solution can be used to deliver the thermal energy to the tissue.
• the electrolytic solution may be cooled in the range of about 30 to 55 degrees C.
• Catheter 14 includes a catheter tissue interface surface 22, a cooling medium inlet conduit 24 and a cooling medium exit conduit 26 extending through an interior of catheter 14.
• Ports 18 are formed in the exterior of catheter 14, and are preferably formed on catheter tissue interface surface 22. Ports 18 are isolated from a cooling medium flowing in inlet and outlet conduits 24 and 26. Cooling medium inlet and exit conduits 24 and 26 are configured to provide a cooled section of catheter tissue interface surface 22 of at least 1 to 2 cm 2 . More preferably, the cooled section of catheter tissue interface surface 22 is at least equal to the cross-sectional diameter ofthe underlying zone of ablation.
• the cooled section of catheter tissue interface surface 22 is at least equal to the cross-sectional diameter ofthe underlying zone of ablation. In another embodiment, the cooled section of catheter tissue interface surface 22 only provides cooling to an area associated with each deployed ablation source delivery device.
• the size ofthe cooled section of catheter tissue interface surface 22 varies for each patient.
• the size is sufficient enough to minimize swelling ofthe tongue following the delivery of electromagnetic energy.
• the reduction of swelling can be 50% or greater, 75% or greater , and 90% and greater.
• the amount of cooling provided is sufficient to enable the patient to return home shortly after the debulking procedure is performed, and not run the risk of choking on the tongue. It has been found that by providing a sufficient level of cooling over a relatively large area, the amount of ablation in an interior region ofthe tongue is enhanced. By providing a sufficiently large enough cooled section of catheter tissue interface surface 22, an adenomas response is minimized.
• Handle 16 is preferably made of an insulating material. Electrodes 12 are made of a conductive material such as stainless steel. Additionally, electrodes 12 can be made of a shaped memory metal, such as nickel titanium, commercially available from Raychem Corporation, Menlo Park, California. In one embodiment, only a distal end of electrode 12 is made ofthe shaped memory metal in order to effect a desired deflection. When introduced into the oral cavity, catheter 14 can be advanced until a patient's gag response is initiated.
• Catheter 14 is then retracted back to prevent patient's gagging.
• the distal end of electrode 12 can be semi-curved.
• the distal end can have a geometry to conform to an exterior ofthe tongue.
• catheter 14 is a handpiece. In this embodiment, a separate handle 16 is not necessary.
• Debulking apparatus 10 is used to treat an interior region ofthe tongue.
• Catheter 14 has a distal end that is sized to be positioned within an oral cavity.
• Ablation source delivery device 12 is at least partially positioned within an interior of catheter 14.
• Ablation source delivery device 12 includes ablation delivery surface 30.
• Ablation source delivery device 20 is coupled to ablation source delivery device 12 and calibrated to advance ablation source delivery device 12 from catheter 14, including but not limited to a distal position of catheter 14, into the interior ofthe tongue when catheter 14 is positioned adjacent to a surface ofthe tongue.
• Ablation source delivery device 12 is advanced an advancement distance 33 from catheter 14 of sufficient length to treat the interior region ofthe tongue with ablation energy and/or an ablation effect without damaging the hypoglossal nerve or the surface ofthe tongue.
• Catheter 14 can be malleable in order to conform to the surface ofthe tongue when a selected ablation target site is selected.
• An encapsulated soft metal such as copper, or an annealed metal/plastic material can be used to form malleable catheter 14. All or a portion of catheter 14 may be malleable or made of a shaped memory metal.
• a distal end 14' of catheter 14 it is desirable for a distal end 14' of catheter 14 to be deflectable. This can be achieved mechanically or with the use of memory metals.
• a steering wire, or other mechanical structure can be attached to either the exterior or interior of distal end 14'.
• a deflection knob located on handle 16 is activated by the physician causing a steering wire to tighten. This imparts a retraction of distal end 14', resulting in its deflection. It will be appreciated that other mechanical devices can be used in place ofthe steering wire. The deflection may be desirable for tissue sites with difficult access.
• Controlled volumetric reduction ofthe tongue, under feedback control is used to achieve an effective opening in the airway passage.
• a variety of different pain killing medicaments including but not limited to Xylocaine, may be used.
• a digital ultrasonic measurement system can be used. The ultrasound measurement quantifies biological shape changes, provides ultrasonic transmission and reception, uses piezoelectric transducers (crystals) and provides time of flight data.
• a disinfectant medium introduction member 21 may also be introduced into the oral cavity.
• the disinfectant medium can be introduced prior to ablation, during ablation and/or after the ablation. It can be delivered continuously.
• the level of disinfection ofthe oral cavity is selectable as the volume ofthe oral cavity that is disinfected. The degree of disinfection varies. Disinfection is provided to reduce infection ofthe ablated body structure.
• Disinfectant medium introduction member 21 can be introduced before, after or during the introduction of ablation apparatus 10 into the oral cavity. Additionally, disinfectant medium introduction member 21 can be removed at the same time or at a different time that ablation apparatus 10 is removed from the oral cavity.
• Disinfectant medium introduction member 21 can be included in ablation apparatus 10, in an interior of catheter 14 or at an exterior of catheter 14, and may be an introducer with a lumen configured to introduce a disinfectant agent from a disinfectant agent source 23 into all or a selected portion ofthe oral cavity. Disinfectant medium introduction member 21 can be capable of movement within the oral cavity in order to provide for disinfection of all or only a portion ofthe oral cavity.
• the oral cavity is that body internal environment where infectious germs may be introduced into the ablated tongue, soft tissue structure, and the like.
• Disinfectant medium introduction member 21 may be slideably positioned in catheter 14 or at its exterior.
• disinfectant medium introduction member 21 can be an optical fiber coupled to a light energy source, including but not limited to a UV source 25.
• the optical fiber can also be slideably be positioned in the oral cavity.
• the optical fiber is configured to provide for the selective disinfection of all or only a portion ofthe oral cavity and can have a variety of different distal ends to achieve this purpose.
• Suitable disinfectant agents include but are not limited to Peridex, an oral rinse containing 0.12% chlorhexidine glucinate (1, l'-hexanethylenebis[5-(p- chlorophenyl) biganide ⁇ di-D-gluconate in a base containing water, 11.6% alcohol, glycerin, PEG 40 sorbitan arisoterate, flavor, dosium saccharin, and FD&C Blue No. 1.
• Electrodes 12 are at least partially positioned in an interior of catheter 14. Each electrode 12 is advanced and retracted through a port 18 formed in an exterior surface of catheter 14. Advancement and retraction device advances electrodes 12 out of catheter 14, into an interior of a body structure and retracted back into catheter 14. Electrodes 12 pierce an exterior surface of the tongue and are directed to an interior region ofthe tongue. Sufficient electromagnetic energy is delivered by electrodes 12 to the interior ofthe tongue to cause the tongue to become sufficiently ablated and debulked. Electrodes 12 can be hollow to receive a variety of different infusion mediums, including but not limited to saline.
• Electrodes 12 may be limited in the distance that they can be advanced into the tongue. This is achieved with an insulation sleeve, a structure located on electrodes 12 which limits their advancement, or a structure coupled to catheter which limits the advancement of electrodes 12, such as a stop and the like.
• the disinfectant medium can be introduced prior to ablation, during ablation and/or after the ablation. It can be delivered continuously.
• the level of disinfection ofthe oral cavity is selectable as is the volume ofthe oral cavity that is disinfected. The degree of disinfection varies. Disinfection is provided to reduce infection ofthe ablated body structure.
• An ablation delivery surface, such as an electromagnetic energy delivery surface 30 of electrode 12 can be adjusted by inclusion of an adjustable or non- adjustable insulation sleeve 32 ( Figures 3, 4, and 5).
• Insulation sleeve 32 can be advanced and retracted along the exterior surface of electrode 12 in order to increase or decrease the length ofthe electromagnetic energy delivery surface 30.
• Insulation sleeve 32 can be made of a variety of materials including but not limited to nylon, polyimides, other thermoplastics and the like.
• the size of electromagnetic energy delivery surface 30 can be varied by other methods including but not limited to creating a segmented electrode with a plurality of electrodes that are capable of being multiplexed and individually activated, and the like.
• ablation source delivery device 12 has an advancement length 33 that extends from an exterior surface of catheter 14 and is directed into the interior ofthe tongue. Advancement length 33 is sufficient to position ablation delivery surface 30 at a selected tissue site in the interior ofthe tongue.
• Ablation delivery surface 30 is of sufficient length so that the ablation effect is delivered to the selected tissue site, create a desired level of ablation at the selected tissue site without causing damage to the hypoglossal nerve.
• Ablation delivery surface 30 is not always at the distal end of ablation source delivery device 12. Insulation 32 can also be positioned at the distal end of ablation source delivery device 12. In this embodiment, ablation delivery surface 30 does not extend to the distal end of ablation source delivery device 12. However, ablation delivery surface 30 still delivers a sufficient ablation effect to create a desired level of cell necrosis in the interior ofthe tongue at the selected tissue site without damaging the hypoglossal nerve and/or damage to the surface ofthe tongue.
• ablation source delivery device 12 can be insulated. This also provides for an ablation source delivery device 12 which can be positioned throughout the tongue, including adjacent to a hypoglossal nerve. Where ablation source delivery device 12 is adjacent to the hypoglossal nerve, ablation source delivery device 12 is insulated.
• advancement length 33 is 1.2 to 1.5 cm, and the length of ablation delivery surface 30 is 5 to 10 mm, more preferably about 8 mm.
• advancement length 33 is insufficient to reach the hypoglossal nerve when introduced through any ofthe tongue surfaces, particularly the dorsum ofthe tongue.
• Advancement device 20 is configured to advance at least a portion of each ablation source delivery device 12 to a placement position in the interior of the tongue. Advancement device 20 can also be configured to retract each ablation source delivery device 12. At the placement position, ablation delivery surface delivers sufficient ablation energy and/or effect to reduce a volume ofthe selected site without damaging a hypoglossal nerve and/or a surface ofthe tongue.
• ablation source delivery device advancement and retraction device 20, with or without guide tracks 23, directs the delivery of ablation source delivery device 12 from catheter 14 into the interior ofthe tongue at an angle of 60 to 90 degrees relative to a longitudinal axis of catheter
• ablation source delivery device 12 has a geometric shape, including but not limited to a curved configuration that includes one or more insulated surfaces, either partially insulated on one side, at a proximal end, at a distal end, and the like, that is configured to reduce the volume ofthe selected tissue site without damaging a hypoglossal nerve.
• ablation source delivery device 12 is introduced through any tongue surface and is configured so that a section of ablation source delivery device 12 which may be positioned close to the hypoglossal nerve is provided with insulation 32. As previously noted, insulation 32 can be positioned at difTerent sites of ablation source delivery device 12.
• Handle 16 can comprise a connector 34 coupled to retraction and advancement device 20.
• Connector 34 provides a coupling of electrodes 12 to power, feedback control, temperature and/or imaging systems.
• An RF/temperature control block 36 can be included.
• Electrodes 12 can be spring loaded. When retraction and advancement device 20 is moved back, springs cause selected electrodes 12 to advance out of catheter 14.
• One or more cables 38 couple electrodes 12 to an electromagnetic energy source 40.
• a variety of energy sources 40 can be used with the present invention to transfer electromagnetic energy to the interior of a body structure, including but not limited to RF, microwave, ultrasound, coherent light and thermal transfer.
• energy source 40 is a RF generator. When a RF energy source is used, the physician can activate RF energy source 40 by the use of a foot switch (not shown) coupled to RF energy source 40.
• One or more sensors 42 may be positioned on an interior or exterior surface of electrode 12, insulation sleeve 32, or be independently inserted into the interior ofthe body structure. Sensors 42 permit accurate measurement of temperature at a tissue site in order to determine, (i) the extent of ablation, (ii) the amount of ablation, (iii) whether or not further ablation is needed, and (iv) the boundary or periphery ofthe ablated geometry. Further, sensors 42 prevent non-targeted tissue from being destroyed or ablated.
• Sensors 42 are of conventional design, including but not limited to thermistors, thermocouples, resistive wires, and the like. Suitable sensors 42 include a T type thermocouple with copper constantene, J type, E type, K type, fiber optics, resistive wires, thermocouple IR detectors, and the like. It will be appreciated that sensors 42 need not be thermal sensors.
• Sensors 42 measure temperature and/or impedance to permit ablation monitoring. This reduces damage to tissue surrounding the targeted ablation mass. By monitoring the temperature at various points within the interior ofthe body structure the periphery of ablation can be ascertained and it is possible to determine when the ablation is completed. If at any time sensor 42 determines that a desired ablation temperature is exceeded, then an appropriate feedback signal is received at energy source 40 and the amount of energy delivered is regulated.
• Ablation or debulking apparatus 10 can include visualization capability including but not limited to a viewing scope, an expanded eyepiece, fiber optics, video imaging, and the like.
• ultrasound imaging can be used to position the electrodes 12 and/or determine the amount of ablation.
• One or more ultrasound transducers 44 can be positioned in or on electrode 12, catheter 14, or on a separate device.
• An imaging probe may also be used internally or externally to the selected tissue site.
• a suitable imaging probe is Model 21362, manufactured and sold by Hewlett Packard Company.
• Each ultrasound transducer 44 is coupled to an ultrasound source (not shown).
• catheter 14 is shown as being introduced into the oral cavity and multiple RF electrodes 12 are advanced into the interior ofthe tongue creating different ablation zones 46.
• ablation apparatus 10 can be operated in either bipolar or monopolar modes. In Figure 6, electrodes 12 are operated in the bipolar mode, creating sufficient ablation zones
• ablation apparatus 10 can also be operated in the monopolar mode.
• a groundpad can be positioned in a convenient place such as under the chin.
• a single electrode 12 is positioned in the tongue to create a first ablation zone 46. Electrode 12 can then be retracted from the interior ofthe tongue, catheter 14 moved, and electrode 12 is then advanced from catheter 14 into another interior section ofthe tongue. A second ablation zone 46 is created.
• Electrodes 12 can be introduced into the tongue and operated in the bipolar mode. Electrodes 12 are then repositioned in the interior ofthe tongue any number of times to create a plurality of connecting or non-connecting ablation zones 46.
• the genioglossus muscle, or body ofthe tongue is denoted as 48; the geniohyoid muscle is 50; the mylohyoid muscle is 52; the hyoid bone is 54; the tip ofthe tongue is 56; the ventral surface ofthe tongue is denoted as 58; the dorsum ofthe tongue is denoted as 60; the inferior dorsal ofthe tongue is denoted as 62; the reflex ofthe vallecula is 64; the lingual follicles are denoted as 66; the uvula is 68; the adenoid area is 70; the lateral border ofthe tongue is 72; the circumvallate papilla is 74, the palatine tonsil is 76; the pharynx is 78; the redundant pharyngeal tissue is 80; the foramen cecum
• Dorsum 60 is divided into an anterior 2/3 and inferior dorsal 62.
• the delineation is determined by circumvallate papilla 74 and foramen cecum 82.
• Inferior dorsal 62 is the dorsal surface inferior to circumvallate papilla 74 and superior reflex ofthe vallecula 64.
• Reflex ofthe vallecula 64 is the deepest portion ofthe surface ofthe tongue contiguous with the epiglottis.
• Lingual follicles 66 comprise the lingual tonsil.
• Catheter 14 can be introduced through the nose or through the oral cavity. Electrodes 12 can be inserted into an interior ofthe tongue through dorsum surface 60, inferior dorsal surface 62, ventral surface 58, tip 56 or geniohyoid muscle 50. Additionally, electrodes may be introduced into an interior of lingual follicles 66 and into adenoid area 70. Once electrodes 12 are positioned, insulation sleeve 32 may be adjusted to provided a desired electromagnetic energy delivery surface 30 for each electrode 12.
• Ablation zones 46 are created without damaging hypoglossal nerves 84. This creates a larger air way passage and provides a treatment for sleep apnea.
• the positioning of electrodes 12, as well as the creation of ablation zones 46 is such that hypoglossal nerves 84 are not ablated or damaged. The ability to swallow and speak is not impaired.
• RF electrode 12 are placed on the dorsum surface ofthe tongue.
• the first electrode is positioned 0.5 cm proximal to the circumvallate pappilla.
• the other electrodes are spaced 1.6 cm apart and are 1 cm off a central axis ofthe tongue.
• 465 MHz RF was applied.
• the temperature at the distal end of electrode 12 was about 100 degrees C.
• the temperature at the distal end ofthe insulation sleeve 32 was about 60 degrees C. In another embodiment, the temperature at the distal end of insulation sleeve 32 was 43 degrees C and above.
• RF energy can be applied as short duration pulses with low frequency RF. Precise targeting of a desired ablation site is achieved.
• One or more electrodes 12 may be used to create volumetric three-dimensional ablation.
• a variety of ablation geometries are possible, including but not limited to rectilinear, polyhedral, redetermined shapes, symmetrical and non-symmetrical.
• an open or closed loop feedback system couples sensors 42 to energy source 40.
• the temperature of the tissue, or of electrode 12 is monitored, and the output power of energy source 40 adjusted accordingly. Additionally, the level of disinfection in the oral cavity can be monitored.
• the physician can, if desired, override the closed or open loop system.
• a microprocessor can be included and incorporated in the closed or open loop system to switch power on and off, as well as modulate the power.
• the closed loop system utilizes a microprocessor 88 to serve as a controller, watch the temperature, adjust the RF power, look at the result, refeed the result, and then modulate the power.
• a tissue adjacent to RF electrodes 12 can be maintained at a desired temperature for a selected period of time without impeding out.
• Each RF electrode 12 is connected to resources which generate an independent output for each RF electrode 12.
• An output maintains a selected energy at RF electrodes 12 for a selected length of time.
• Signals representative of power and impedance values are received by a controller 98.
• a control signal is generated by controller 98 that is proportional to the difference between an actual measured value, and a desired value.
• the control signal is used by power circuits 100 to adjust the power output in an appropriate amount in order to maintain the desired power delivered at respective RF electrodes 12.
• temperatures detected at sensors 42 provide feedback for maintaining a selected power.
• the actual temperatures are measured at temperature measurement device 102, and the temperatures are displayed at user interface and display 96.
• a control signal is generated by controller 98 that is proportional to the difference between an actual measured temperature, and a desired temperature.
• the control signal is used by power circuits 100 to adjust the power output in an appropriate amount in order to maintain the desired temperature delivered at the respective sensor.
• a multiplexer can be included to measure current, voltage and temperature, at the numerous sensors 42, and energy can be delivered to RF electrodes 12 in monopolar or bipolar fashion.
• Controller 98 can be a digital or analog controller, or a computer with software.
• controller 98 is a computer it can include a CPU coupled through a system bus.
• On this system can be a keyboard, a disk drive, or other non-volatile memory systems, a display, and other peripherals, as are known in the art.
• Also coupled to the bus is a program memory and a data memory.
• User interface and display 96 includes operator controls and a display.
• Controller 98 can be coupled to imaging systems, including but not limited to ultrasound, CT scanners, X-ray, MRI, mammographic X-ray and the like.
• the output of current sensor 90 and voltage sensor 92 is used by controller 98 to maintain a selected power level at RF electrodes 12.
• the amount of RF energy delivered controls the amount of power.
• a profile of power delivered can be incorporated in controller 98, and a preset amount of energy to be delivered can also be profiled.
• Other sensors similar to sensors 90 and 92 can be used by controller 98 for other ablation source delivery devices 12 to maintain a controllable amount of an ablation energy and/or ablative agent.
• Circuitry, software and feedback to controller 98 result in process control, and the maintenance ofthe selected power that is independent of changes in voltage or current, and are used to change, (i) the selected power, (ii) the duty cycle (on-off and wattage), (iii) bipolar or monopolar energy delivery, and (iv) infusion medium delivery, including flow rate and pressure.
• process variables are controlled and varied, while maintaining the desired delivery of power independent of changes in voltage or current, based on temperatures monitored at sensors 42.
• Current sensor 90 and voltage sensor 92 are connected to the input of an analog amplifier 104.
• Analog amplifier 104 can be a conventional differential amplifier circuit for use with sensors 42.
• the output of analog amplifier 104 is sequentially connected by an analog multiplexer 106 to the input of A D converter 108.
• the output of analog amplifier 104 is a voltage which represents the respective sensed temperatures. Digitized amplifier output voltages are supplied by A/D converter 108 to microprocessor 88. Microprocessor 88 may be a type 68HCII available from Motorola. However, it will be appreciated that any suitable microprocessor or general purpose digital or analog computer can be used to calculate impedance or temperature.
• Microprocessor 88 sequentially receives and stores digital representations of impedance and temperature. Each digital value received by microprocessor 88 conesponds to different temperatures and impedances.
• Calculated power and impedance values can be indicated on user interface and display 96.
• calculated impedance and power values can be compared by microprocessor 88 with power and impedance limits. When the values exceed predetermined power or impedance values, a warning can be given on user interface and display 96, and additionally, the delivery of RF energy can be reduced, modified or interrupted.
• a control signal from microprocessor 88 can modify the power level supplied by energy source 40.
• FIG. 18 illustrates a block diagram of a temperature/impedance feedback system that can be used to control cooling medium flow rate through catheter 14.
• Electromagnetic energy is delivered to electrode 12 by energy source 44, and applied to tissue.
• a monitor 110 ascertains tissue impedance, based on the energy delivered to tissue, and compares the measured impedance value to a set value. If the measured impedance exceeds the set value a disabling signal 112 is transmitted to energy source 40, ceasing further delivery of energy to electrode 12. If measured impedance is within acceptable limits, energy continues to be applied to the tissue.
• tissue sensor 42 measures the temperature of tissue and/or electrode 12.
• a comparator 114 receives a signal representative ofthe measured temperature and compares this value to a pre-set signal representative ofthe desired temperature. Comparator 114 sends a signal to a flow regulator 116 representing a need for a higher cooling medium flow rate, if the tissue temperature is too high, or to maintain the flow rate if the temperature has not exceeded the desired temperature.
• EXAMPLE 1 Ablation apparatus 10 was used to determine two-dimensional shrinkage of a bovine. RF volumetric reduction was achieved using a single needle electrode. Four miniature ultrasonic crystals were positioned to form a square.
• Ablation apparatus 10 was used to determine three-dimensional shrinkage of a bovine tongue. RF volumetric reduction was achieved with a single needle electrode with eight miniature ultrasonic crystals, creating a cube. Application of 16 watts initially produced a 17% volumetric reduction ofthe tongue, 25 watts applied initially produced a 25% volumetric reduction, and 25 watts after hours produced an additional 4% reduction, for a total volumetric reduction of 29%.
• EXAMPLE 3 A 35% volumetric reduction was achieved in porcine in vivo, with three dimensional gross at 20 watts initial application.
• FIG 19 ablation volume dimensions were measured with a multidimensional digital sonomicrometry. An average decrease in the Z direction was 20%, and volume shrinkage was 26%. Three-dimensional shrinkage of tongue tissue due to in vivo RF ablation with the needle, ablation with 20 Watts) is presented in Figure 20. Control volume before ablation is compared with a post-ablation volume. Figure 20 illustrates two-dimensional shrinkage of a bovine tongue tissue due to RF ablation with a needle electrode. The before and after ablation results are illustrated.
• Figure 21 illustrates in graph form ablation at 16 Watts resulted in a 17% volume shrinkage ofthe tissue in post-ablation verses control. Ablation at 25 watts resulted in a 25% volume shrinkage after ablation. An additional 4% area shrinkage was obtained after in long-term post ablation (4 hours) verses post- ablation.
• Figure 22 illustrates a percent volume change after RF ablation. 16 Watts, ablation at 16 Watts for 20 minutes; 25 Watts, ablation at 25 Watts for 20 minutes; 25 Watts (4 hours), and long tern post ablation (4 hours after 25 Watts ablation).

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• 1996
  • 1996-08-16 JP JP9509552A patent/JPH11511054A/ja active Pending
  • 1996-08-16 WO PCT/US1996/013419 patent/WO1997006741A2/en not_active Application Discontinuation
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