title: Radiofrequency volumetric reduction of the tongue. A porcine pilot study for the treatment of obstructive sleep apnea syndrome.
abstract: OBJECTIVE
  To investigate, in an animal model, the feasibility of radiofrequency (RF) volumetric tongue reduction for the future purpose of determining its clinical applications in obstructive sleep apnea syndrome (OSAS).
  
  
  METHODS
  The study was performed in three stages, one in vitro bovine stage and two in vivo porcine stages. The last stage was a prospective investigation with histologic and volumetric analyses to establish outcomes.
  
  
  METHODS
  Laboratory and operating room of veterinary research center.
  
  
  METHODS
  A homogeneous population of porcine animal models, including seven in stage 2 and 12 in stage 3.
  
  
  METHODS
  RF energy was delivered by a custom-fabricated needle electrode and RF generator to the tongue tissue of both the in vitro and in vivo models.
  
  
  RESULTS
  Microultransonic crystals were used to measure three-dimensional changes (volumetric reduction). Lesion size correlated well with increasing RF energy delivery (Sperman correlation coefficient of 0.986; p = 0.0003). Histologic assessments done serially over time (1 h through 3 weeks) showed a well-circumscribed lesion with a normal healing progression and no peripheral damage to nerves. Volumetric analysis documented a very mild initial edematous response that promptly tapered at 24 h. At 10 days after RF, a 26.3% volume reduction was documented at the treatment site (circumscribed by the microultrasonic crystals).
  
  
  CONCLUSIONS
  RF, in a porcine animal model, can safely reduce tongue volume in a precise and controlled manner. Further studies will validate the use of RF in the treatment of OSAS.
authors.affiliation: Stanford University Sleep Disorders and Research Center, Calif., USA.
authors.forename: N B
authors.initials: NB
authors.lastname: Powell
authors.forename: R W
authors.initials: RW
authors.lastname: Riley
authors.forename: R J
authors.initials: RJ
authors.lastname: Troell
authors.forename: M B
authors.initials: MB
authors.lastname: Blumen
authors.forename: C
authors.initials: C
authors.lastname: Guilleminault
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D002417:Cattle; D004195:Disease Models, Animal; D004487:Edema / Q000209:etiology / Q000473:pathology; D011211:Electric Power Supplies; D004566:Electrodes; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D005927:Glossectomy / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D008297:Male; D009339:Needles; D010865:Pilot Projects; D011446:Prospective Studies; D015203:Reproducibility of Results; D012891:Sleep Apnea Syndromes / Q000601:surgery*; D013552:Swine; D014059:Tongue / Q000000981:diagnostic imaging / Q000294:innervation / Q000473:pathology / Q000601:surgery*; D014060:Tongue Diseases / Q000209:etiology / Q000473:pathology; D016896:Treatment Outcome; D014463:Ultrasonography; D014945:Wound Healing