Comparative Effects of Snoring Sound between Two Minimally Invasive Surgeries in the Treatment of Snoring: A Randomized Controlled Trial

<div><p>Background</p><p>Minimally invasive surgeries of the soft palate have emerged as a less-invasive treatment for habitual snoring. To date, there is only limited information available comparing the effects of snoring sound between different minimally invasive surgeries in the treatment of habitual snoring.</p><p>Objective</p><p>To compare the efficacy of palatal implant and radiofrequency surgery, in the reduction of snoring through subjective evaluation of snoring and objective snoring sound analysis.</p><p>Patients and Method</p><p>Thirty patients with habitual snoring due to palatal obstruction (apnea-hypopnea index ≤15, body max index ≤30) were prospectively enrolled and randomized to undergo a single session of palatal implant or temperature-controlled radiofrequency surgery of the soft palate under local anesthesia. Snoring was primarily evaluated by the patient with a 10 cm visual analogue scale (VAS) at baseline and at a 3-month follow-up visit and the change in VAS was the primary outcome. Moreover, life qualities, measured by snore outcomes survey, and full-night snoring sounds, analyzed by a sound analytic program (Snore Map), were also investigated at the same time.</p><p>Results</p><p>Twenty-eight patients completed the study; 14 received palatal implant surgery and 14 underwent radiofrequency surgery. The VAS and snore outcomes survey scores were significantly improved in both groups. However, the good response (postoperative VAS ≤3 or postoperative VAS ≤5 plus snore outcomes survey score ≥60) rate of the palatal implant group was significantly higher than that of the radiofrequency group (79% <i>vs</i>. 29%, P = 0.021). The maximal loudness of low-frequency (40–300 Hz) snores was reduced significantly in the palatal implant group. In addition, the snoring index was significantly reduced in the radiofrequency group.</p><p>Conclusions</p><p>Both palatal implants and a single-stage radiofrequency surgery improve subjective snoring outcomes, but palatal implants have a greater effect on most measures of subjective and objective snoring. Multi-stage radiofrequency surgery was not tested.</p><p>Trial Registration</p><p>ClinicalTrials.gov <a href="http://clinicaltrials.gov/show/NCT01955083" target="_blank">NCT01955083</a></p></div

Objective snoring sound parameters at baseline for the entire study cohort (<i>n</i> = 30).

<p>Values were given as mean (standard error). AHI: apnea-hypopnea index. BMI: body mass index. CI: conference interval; PSG-SI: polysomnography-defined snoring index. SOS: snoring outcomes survey. VAS: visual analogue scale.</p><p>*Statistical analyses were implemented with the Mann-Whitney <i>U</i> test.</p

Radiofrequency surgery.

<p>(A) Preoperative frontal view illustrating the 3 operative sites of the soft palate (1.0 cm below the hard palate-soft palate junction; 1.0 cm between the midline and para-midline sites). (B) Postoperative frontal view demonstrating the stiffened zone (grey zone) by the RF energy (1.0 cm×2.6 cm).</p

Results of objective snoring sound parameters before and after treatment in the two groups.

<p>CI: conference interval. Fmean: mean sound frequency. Fpeak: peak sound frequency. Imax: maximal sound intensity. Imean: mean sound intensity.</p

Comparison of the postoperative changes in subjective questionnaire scores between the palatal implant and radiofrequency surgery groups.

<p>CI: conference interval. SOS: snore outcomes survey. VAS: visual analogue scale.</p

Patient characteristics for the entire study cohort (<i>n</i> = 30).

<p>Values were given as mean (standard error). AHI: apnea-hypopnea index. BMI: body mass index. CI: conference interval; PSG-SI: polysomnography-defined snoring index. SOS: snoring outcomes survey. VAS: visual analogue scale.</p><p>*Statistical analyses were implemented with the Mann-Whitney <i>U</i> test.</p

Palatal implant surgery.

<p>(A) Preoperative frontal view demonstrating the 3 operative sites of the soft palate (0.5 cm below the hard palate-soft palate junction; 0.2 cm between the midline and para-midline sites). (B) Postoperative frontal view showing the stiffened zone (grey zone) by the implant (1.8 cm×0.94 cm).</p

Schematic diagram (CONSORT 2010 flowchart diagram) summarizing the study design.

<p>AHI: apnea-hypopnea index. PI: palatal implant; RF, radiofrequency. SOS: snoring outcomes survey. VAS: visual analogue scale.</p

Favorable anatomy for the MIS of the soft palate in anti-snoring treatment.

<p>(A) Frontal view showing the longitudinal length from the uvular base to the hard palate-soft palate junction ≥ 2.5 cm and the lateral width of the uvular base ≥ 1.0 cm. (B) Lateral view illustrating the anterior-posterior width of the uvular base ≥ 1.0 cm.</p