Effects of surgery on the phonation threshold pressure in patients with vocal fold polyps.

Background/purpose: There are few objective measurements to assess the results of surgery for vocal fold polyps. This study investigated the effects of surgery on the phonation threshold pressure (PTP) in patients with vocal fold polyps.

Methods: Prospectively, 32 consecutive patients with vocal fold polyps were enrolled. PTP was measured 1 day before and 6 weeks after laryngomicrosurgery, by means of an airflow interruption method. An accelerometer was used to detect the vocal fold vibration instead of using an acoustic signal.

Results: In all 32 patients, the average preoperative PTP was 0.51 +/- 0.23 kPa, and 6 weeks after surgery, it was 0.28 +/- 0.17 kPa; this difference was statistically significant (p < 0.001). Individually, PTP decreased in 31 patients after surgery. PTP increased after surgery in only one patient, from 0.74 to 0.75 kPa. Subjectively, all patients could phonate with less effort after surgery. Use of an accelerometer to sense vocal fold vibration was feasible and made it easier to identify the time point of cessation of vocal fold vibration, which is important for PTP measurement.

Conclusion: Laryngomicrosurgery can lower PTP in patients with vocal fold polyps and improve the ease of phonation. PTP is one of the objective measurements for assessing the effects of surgery in patients with vocal fold polyps. Use of an accelerometer to detect vocal fold vibration improved the measurement of PTP.