Obstructive Sleep Apnea, Primary Snoring
Conditions
Keywords
Obstructive sleep apnea, snoring, radiofrequency, pillar implant, snore sound analysis
Brief 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.
Interventions
DEVICEPillar implant
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.
DEVICERadiofrequency
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).
Sponsors
National Science and Technology Council, Taiwan
Chang Gung Memorial Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
20 Years to 60 Years
Healthy volunteers
No
Inclusion criteria
1. simple snoring or mild obstructive sleep apnea 2. major complaint of snoring 3. favorable anatomic structure for minimal invasive surgery.
Exclusion criteria
1. moderate or severe obstructive sleep apnea 2. pathological obesity 3. significant craniofacial anomaly 4. elderly 5. unfavorable anatomic structure for minimal invasive surgery.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in VAS Score After MIS | baseline and 3 months following surgery | The mean change in subjective snoring severity (VAS) at 3 months after MIS was the primary outcome measurement. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Percent Change in Total-SI After MIS | baseline and 3 months following surgery | Percent change (\[after value-before value\]/\[before value\]\*100) in Total-SI (event/hour) before and at 3 months after surgery was calculated. |
| Percent Change in Total-Imax After MIS | baseline and 3 months following surgery | Percent change (\[after value-before value\]/\[before value\]\*100) in Total-Imax (dB) before and at 3 months after surgery was calculated. |
| Percent Change in Total-Imean After MIS | baseline and 3 months following surgery | Percent change (\[after value-before value\]/\[before value\]\*100) in Total-Imean (dB) before and at 3 months after surgery was calculated. |
| Percent Change in Total-Fpeak After MIS | baseline and 3 months following surgery | Percent change (\[after value-before value\]/\[before value\]\*100) in Total-Fpeak (Hz) before and at 3 months after surgery was calculated. |
| Percent Change in Total-Fmean After MIS | baseline and 3 months following surgery | Percent change (\[after value-before value\]/\[before value\]\*100) in Total-Fmean (Hz) before and at 3 months after surgery was calculated. |
| Change in SOS Score After MIS | baseline and 3 months following surgery | Change in SOS score at 3 months after radiofrequency or pillar implant were calculated. |
| Percent Change in B1-Imax After MIS | baseline and 3 months following surgery | Percent change (\[after value-before value\]/\[before value\]\*100) in B1-Imax (dB) before and at 3 months after surgery was calculated. |
| Percent Change in B1-Imean After MIS | baseline and 3 months following surgery | Percent change (\[after value-before value\]/\[before value\]\*100) in B1-Imean (dB) before and at 3 months after surgery was calculated. |
| Percent Change in B1-Fpeak After MIS | baseline and 3 months following surgery | Percent change (\[after value-before value\]/\[before value\]\*100) in B1-Fpeak (Hz) before and at 3 months after surgery was calculated. |
| Percent Change in B1-Fmean After MIS | baseline and 3 months following surgery | Percent change (\[after value-before value\]/\[before value\]\*100) in B1-Fmean (Hz) before and at 3 months after surgery was calculated. |
| Percent Change in B1-SI After MIS | baseline and 3 months following surgery | Percent change (\[after value-before value\]/\[before value\]\*100) in B1-SI (event/hour) before and at 3 months after surgery was calculated. |
Countries
Taiwan
Participant flow
Recruitment details
This study was a prospective, randomized, parallel-controlled trial in a tertiary medical center (Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan). Subjects were recruitment from October 1, 2010 to March 31, 2012.
Pre-assignment details
The additional inclusion criteria were: a) length of the soft palate ≥ 2.5 cm and b) the width of the base of the uvular ≥ 1.0 cm. The exclusion criteria were: a) tonsillar hypertrophy; b) high tongue position; c) retrognathia; d) craniofacial abnormalities, e) trismus, f) allergy to anesthetic, and g) poorly controlled medical disorders.
Participants by arm
| Arm | Count |
|---|---|
| Radiofrequency Arm 2- Radiofrequency (control group):
15 subjects undergo radiofrequency of the soft palate for the treatment of snoring. | 15 |
| Pillar Implant Arm 1- Pillar implant (Study group):
15 subjects undergo pillar implant surgery of the soft palate for the treatment of snoring. | 15 |
| Total | 30 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Lost to Follow-up | 1 | 1 |
Baseline characteristics
| Characteristic | Radiofrequency | Pillar Implant | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 15 Participants | 15 Participants | 30 Participants |
| Age, Continuous | 35.1 years STANDARD_DEVIATION 7.3 | 38.3 years STANDARD_DEVIATION 9.7 | 36.7 years STANDARD_DEVIATION 8.6 |
| B1-Fmean | 101.9 Hz STANDARD_DEVIATION 28.4 | 98.0 Hz STANDARD_DEVIATION 24.1 | 100.0 Hz STANDARD_DEVIATION 26 |
| B1-Fpeak | 220.7 Hz STANDARD_DEVIATION 54.8 | 217.3 Hz STANDARD_DEVIATION 39.2 | 219.0 Hz STANDARD_DEVIATION 46.9 |
| B1-Imax | 53.9 dB STANDARD_DEVIATION 7.8 | 63.8 dB STANDARD_DEVIATION 9.9 | 58.9 dB STANDARD_DEVIATION 10.1 |
| B1-Imean | 44.8 dB STANDARD_DEVIATION 7.5 | 47.2 dB STANDARD_DEVIATION 4.2 | 46.0 dB STANDARD_DEVIATION 6.1 |
| B1-SI | 113.3 event/hour STANDARD_DEVIATION 148.9 | 113.4 event/hour STANDARD_DEVIATION 93.5 | 113.3 event/hour STANDARD_DEVIATION 122.2 |
| Region of Enrollment Taiwan | 15 participants | 15 participants | 30 participants |
| Sex: Female, Male Female | 3 Participants | 0 Participants | 3 Participants |
| Sex: Female, Male Male | 12 Participants | 15 Participants | 27 Participants |
| SOS | 40.5 units on a scale STANDARD_DEVIATION 9.4 | 40.4 units on a scale STANDARD_DEVIATION 8.8 | 40.5 units on a scale STANDARD_DEVIATION 8.9 |
| Total-Fmean | 102.3 Hz STANDARD_DEVIATION 30.4 | 10.4 Hz STANDARD_DEVIATION 22.7 | 101.9 Hz STANDARD_DEVIATION 26.4 |
| Total-Fpeak | 617.3 Hz STANDARD_DEVIATION 603.8 | 543.3 Hz STANDARD_DEVIATION 593.1 | 580.3 Hz STANDARD_DEVIATION 589.3 |
| Total-Imax | 57.7 dB STANDARD_DEVIATION 8.2 | 70.9 dB STANDARD_DEVIATION 13.1 | 64.3 dB STANDARD_DEVIATION 12.7 |
| Total-Imean | 47.4 dB STANDARD_DEVIATION 7.6 | 50.8 dB STANDARD_DEVIATION 5 | 49.1 dB STANDARD_DEVIATION 6.6 |
| Total-SI | 116.4 event/hour STANDARD_DEVIATION 148.6 | 116.3 event/hour STANDARD_DEVIATION 94.2 | 116.3 event/hour STANDARD_DEVIATION 122.2 |
| VAS | 6.8 units on a scale STANDARD_DEVIATION 2 | 7.9 units on a scale STANDARD_DEVIATION 1.7 | 7.3 units on a scale STANDARD_DEVIATION 1.9 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 15 | 0 / 15 |
| serious Total, serious adverse events | 0 / 15 | 0 / 15 |
Outcome results
Primary
Change in VAS Score After MIS
The mean change in subjective snoring severity (VAS) at 3 months after MIS was the primary outcome measurement.
Time frame: baseline and 3 months following surgery
Population: Twenty-eight patients completed the protocol; two study cases were not available for follow-up. Fourteen patients underwent radiofrequency surgery and 14 patients received pillar implant surgery. Accordingly, we analyzed the participants who completed the study protocol.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Change in VAS Score After MIS | -1.4 units on a scale | 95% Confidence Interval 7.2 |
| Change in VAS Score at 3 Months After Pillar Implant | Change in VAS Score After MIS | -3.3 units on a scale | 95% Confidence Interval 9 |
Comparison: We hypothesized that pillar implant provide a better efficacy in the treatment of snoring than radiofrequency surgery. The sample size was estimated using the primary outcome effects (VAS) in two previously published studies (Friedman 2008; Fang 2004). Using a two-tailed Wilcoxon signed-rank test (normal parent distribution; effect size, 1.0; type I error, 0.05; power, 80%), we got a sample size of 11. For considering a 20% drop-out rate, we needed at least 14 participants.p-value: <0.0595% CI: [-14.4, 48.4]Wilcoxon (Mann-Whitney)
Secondary
Change in SOS Score After MIS
Change in SOS score at 3 months after radiofrequency or pillar implant were calculated.
Time frame: baseline and 3 months following surgery
Population: Twenty-eight participants completed the follow-up protocol and two participants dropped out after surgery.
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Change in SOS Score After MIS | 13.0 units on a scale |
| Change in VAS Score at 3 Months After Pillar Implant | Change in SOS Score After MIS | 22.8 units on a scale |
p-value: <0.05Wilcoxon (Mann-Whitney)
Secondary
Percent Change in B1-Fmean After MIS
Percent change (\[after value-before value\]/\[before value\]\*100) in B1-Fmean (Hz) before and at 3 months after surgery was calculated.
Time frame: baseline and 3 months following surgery
Population: A total of 28 participants completed the follow-up protocol and two participants dropped out after surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Percent Change in B1-Fmean After MIS | -24.8 percentage of B1-Fmean | Standard Error 8.7 |
| Change in VAS Score at 3 Months After Pillar Implant | Percent Change in B1-Fmean After MIS | -1.6 percentage of B1-Fmean | Standard Error 8.4 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Secondary
Percent Change in B1-Fpeak After MIS
Percent change (\[after value-before value\]/\[before value\]\*100) in B1-Fpeak (Hz) before and at 3 months after surgery was calculated.
Time frame: baseline and 3 months following surgery
Population: A total of 28 participants completed the follow-up protocol and two participants dropped out after surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Percent Change in B1-Fpeak After MIS | -33.5 percentage of B1-Fpeak | Standard Error 11.4 |
| Change in VAS Score at 3 Months After Pillar Implant | Percent Change in B1-Fpeak After MIS | -10.9 percentage of B1-Fpeak | Standard Error 7.9 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Secondary
Percent Change in B1-Imax After MIS
Percent change (\[after value-before value\]/\[before value\]\*100) in B1-Imax (dB) before and at 3 months after surgery was calculated.
Time frame: baseline and 3 months following surgery
Population: A total of 28 participants completed the follow-up protocol and two participants dropped out after surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Percent Change in B1-Imax After MIS | 5.6 percentage of B1-Imax | Standard Error 3.1 |
| Change in VAS Score at 3 Months After Pillar Implant | Percent Change in B1-Imax After MIS | -9.4 percentage of B1-Imax | Standard Error 5.6 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Secondary
Percent Change in B1-Imean After MIS
Percent change (\[after value-before value\]/\[before value\]\*100) in B1-Imean (dB) before and at 3 months after surgery was calculated.
Time frame: baseline and 3 months following surgery
Population: A total of 28 participants completed the follow-up protocol and two participants dropped out after surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Percent Change in B1-Imean After MIS | 14.7 percentage of B1-Imean | Standard Error 5.5 |
| Change in VAS Score at 3 Months After Pillar Implant | Percent Change in B1-Imean After MIS | -4.6 percentage of B1-Imean | Standard Error 5.3 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Secondary
Percent Change in B1-SI After MIS
Percent change (\[after value-before value\]/\[before value\]\*100) in B1-SI (event/hour) before and at 3 months after surgery was calculated.
Time frame: baseline and 3 months following surgery
Population: A total of 28 participants completed the follow-up protocol and two participants dropped out after surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Percent Change in B1-SI After MIS | -51.8 percentage of B1-SI | Standard Error 22.5 |
| Change in VAS Score at 3 Months After Pillar Implant | Percent Change in B1-SI After MIS | -1.7 percentage of B1-SI | Standard Error 29.5 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Secondary
Percent Change in Total-Fmean After MIS
Percent change (\[after value-before value\]/\[before value\]\*100) in Total-Fmean (Hz) before and at 3 months after surgery was calculated.
Time frame: baseline and 3 months following surgery
Population: A total of 28 participants completed the follow-up protocol and two participants dropped out after surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Percent Change in Total-Fmean After MIS | -10.9 percentage of Total-Fmean | Standard Error 11.6 |
| Change in VAS Score at 3 Months After Pillar Implant | Percent Change in Total-Fmean After MIS | -0.9 percentage of Total-Fmean | Standard Error 8.7 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Secondary
Percent Change in Total-Fpeak After MIS
Percent change (\[after value-before value\]/\[before value\]\*100) in Total-Fpeak (Hz) before and at 3 months after surgery was calculated.
Time frame: baseline and 3 months following surgery
Population: A total of 28 participants completed the follow-up protocol and two participants dropped out after surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Percent Change in Total-Fpeak After MIS | -12.1 percentage of Total-Fpeak | Standard Error 26.2 |
| Change in VAS Score at 3 Months After Pillar Implant | Percent Change in Total-Fpeak After MIS | -6 percentage of Total-Fpeak | Standard Error 24.2 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Secondary
Percent Change in Total-Imax After MIS
Percent change (\[after value-before value\]/\[before value\]\*100) in Total-Imax (dB) before and at 3 months after surgery was calculated.
Time frame: baseline and 3 months following surgery
Population: A total of 28 participants completed the follow-up protocol and two participants dropped out after surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Percent Change in Total-Imax After MIS | 11.3 percentage of Total-Imax | Standard Error 3.8 |
| Change in VAS Score at 3 Months After Pillar Implant | Percent Change in Total-Imax After MIS | -6.8 percentage of Total-Imax | Standard Error 5.9 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Secondary
Percent Change in Total-Imean After MIS
Percent change (\[after value-before value\]/\[before value\]\*100) in Total-Imean (dB) before and at 3 months after surgery was calculated.
Time frame: baseline and 3 months following surgery
Population: A total of 28 participants completed the follow-up protocol and two participants dropped out after surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Percent Change in Total-Imean After MIS | 18.2 percentage of Total-Imean | Standard Error 6.1 |
| Change in VAS Score at 3 Months After Pillar Implant | Percent Change in Total-Imean After MIS | -0.4 percentage of Total-Imean | Standard Error 5.6 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Secondary
Percent Change in Total-SI After MIS
Percent change (\[after value-before value\]/\[before value\]\*100) in Total-SI (event/hour) before and at 3 months after surgery was calculated.
Time frame: baseline and 3 months following surgery
Population: A total of 28 participants completed the follow-up protocol and two participants dropped out after surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Percent Change in Total-SI After MIS | -48.9 percentage of Total-SI | Standard Error 22.1 |
| Change in VAS Score at 3 Months After Pillar Implant | Percent Change in Total-SI After MIS | -5.9 percentage of Total-SI | Standard Error 25.6 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Post Hoc
Percentage of Good Response After MIS
Postoperative 'VAS \<=3' was traditionally defined as 'major response'. For a comprehensive profile of the outcomes, we further created another definition of 'fine response': 'postoperative VAS \<=5 plus SOS \>=60' post hoc in the present study. Accordingly, patients with a postoperative VAS \<=3 or postoperative VAS \<=5 plus SOS \>=60' group was considered to have a 'good response'. Therefore, we calculated the 'good response' rate in the radiofrequency and pillar implant groups.
Time frame: baseline and 3 months following surgery
Population: A total of 28 participants completed the follow-up protocol and two participants dropped out after surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Change in VAS Score at 3 Months After Radiofrequency | Percentage of Good Response After MIS | 29 percentage of Good Response | Standard Error 12.5 |
| Change in VAS Score at 3 Months After Pillar Implant | Percentage of Good Response After MIS | 71 percentage of Good Response | Standard Error 12.5 |
p-value: <0.05Fisher Exact