Analysis of Snore Sound Following Minimal Invasive Surgery in Sleep-disordered Breathing Patients
Condition: Primary Snoring; Obstructive Sleep Apnea
MeSH terms: Sleep Apnea Syndromes; Sleep Apnea, Obstructive; Snoring
Study type: Interventional

Summary: 
      1. Background：The methods of anti-snore (treatment of snoring ) can be divided into
           conservative, invasive and minimal invasive treatment. IN brief, minimal invasive
           surgery involving radiofrequency and pillar implant demonstrates significantly
           improvement of snoring without major complication. Previous studies usually evaluated
           snoring through subjective measures such as visual analog scale visual analog scale.
           Rare reports analyzed snore sound instrumentally and no report demonstrates the
           correlation between subjective perception and objective assessment of snoring before and
           after surgical intervention.

        2. Purposes：

             1. Development of snore sound spectrum.

             2. Exploration of the correlation between subjective perception and objective
                assessment of snoring.

             3. Comparison of changes in snoring before and after minimal invasive surgery and
                between two kinds of MIS to have a understanding of surgical impact in subjective
                and objective measurement.

        3. Method：We plan to enroll 30 subjects diagnosed by polysomnography as simple snoring or
           mild OSA with major complaint of snoring and favorable anatomic structure for minimal
           invasive surgery. All eligible subjects will be instructed the purpose, process and all
           related rights of this study and sign inform consent in outpatient clinic. Subjects
           start to complete Snore Outcome Survey (SOS, a validated questionnaire) and visual
           analog sure of snoring (VAS). Objective overnight snore sound recoding is arranged in
           sleep center. Subjects then receive minimal invasive surgery：radiofrequency or pillar
           implant of the soft palate by randomization. Both radiofrequency and pillar implant are
           common techniques in treating snoring and performed under local anesthesia as an
           outpatient procedure on sitting position. All subjects received repeated snore sound
           recording and completion of SOS and VAS three months after MIS.

        4. Outcomes

             1. Development of snore sound spectrum in sleep-disorder breathing patients.

             2. Correlation of parameters between snore sound recording (loudness, frequency,
                count, regularity, etc ) and clinical parameters.

             3. Correlation between objective (snore sound analysis) and subjective (SOS,VAS)
                assessment of snoring.

             4. Comparison of changes in snoring (particular in objective assessment) after
                radiofrequency or pillar implant.

             5. Comparison of changes in snoring between radiofrequency and pillar implant.
    

Detailed description: 
      Recent publications have demonstrated reductions in snoring with several minimal invasive
      surgery (MIS) methods of the soft palate including radiofrequency (RF) surgery and pillar
      implant (PI). Despite modest effects in the treatment of obstructive sleep apnea, patients
      often wish to receive MIS for habitual snoring. However, the efficacy in reducing snoring has
      mainly been determined by self-reported questionnaires in the past. Further, the definition
      of surgical success in snoring treatment has not been universally defined. To date, changes
      in snoring sound characteristics following MIS have not been demonstrated.

      Many cohort studies and a few randomized controlled trials or clinical controlled trials have
      compared MIS with a placebo, different energy generators, different material rigidity, or
      different operative techniques. RF of the soft palate produces volumetric tissue reduction
      and selective scar tissue5 to reduce obstruction and induce stiffness. However, the RF energy
      delivered to the soft palate can be inadequate and may result in residual or recurrent
      snoring. PI can decrease palatal flutter by increasing the rigidity of the soft palate
      through implant identity and tissue fibrosis. In addition, PI can be chronically retained in
      the muscle layer of the soft palate thereby producing a long-term anti-snoring effect.
      Nevertheless, whether PI provides a better efficacy in the treatment of snoring than RF
      surgery is still unknown.

      The primary aim of the current study was to compare the anti-snoring effect between PI and RF
      by subjective assessments in a randomized controlled parallel trial. The secondary aim was to
      explore and compare the acoustic changes in snoring sounds after PI and RF.
    

Intervention name(s): Pillar implant; Radiofrequency
Intervention type(s): Device; Device
Intervention description(s): Subjects receive pillar implant of the soft palate under local anesthesia as an outpatient procedure on sitting position. Using the delivery tool of the pillar implant system, the mucosa of the soft palate close to the hard palate-soft palate junction (approximate 0.5 cm) was punctured in the midline. The needle was inserted to the uvular muscle and moved parallel to the curve of the soft palate towards the tip of the uvula. After reaching the insertion point, the implant was delivered steadily after which the needle was withdrawn. This process was repeated for the second and third implants in the bilateral para-midline with a 0.2 cm horizontal distance from the first implant.; Subjects receive radiofrequency under local anesthesia as an outpatient procedure on sitting position. radiofrequency energy was delivered via a generator (Somnus® Model S2, Gyrus-ACMI Corporation, Maple Grove, MN, USA) with the power set to 10 watts and the maximal target temperature to 85°C. The needle electrode was inserted through the mucosa into the muscle layer at the entry points (approximately 1 cm below the hard palate-soft palate junction). The electrode was kept in place until 600 J had been delivered at the midline and 300 J at both para-midline sites (approximately 1 cm horizontal distance).
Other intervention name(s): Pillar implant (Medtronic Inc., USA); Somnus® Model S2 (Gyrus-ACMI Corporation, USA)
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Obstructive sleep apnea; snoring; radiofrequency; pillar implant; snore sound analysis