Voice Comparison between Strap Muscle Retraction and Cutting Technique in Thyroidectomy / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: A voice analysis was carried out before and after thyroid surgeries without laryngeal nerve injury, between strap muscle retraction and cutting group in thyroid surgery. The study was done by means of questionaires, acoustics and aerodynamic analysis. MATERIALS AND METHODS: A total of fourty-two patients of whom thirty-eight are females and four are males were analyzed; hemithyroidectomy (19 cases) and total thyroidectomy (23 cases). Twenty-seven patients had undergone thyroidectomy via retraction of strap muscle and 15 patients had undergone thyroidectomy via cutting of strap muscle. For evaluation of voice, questionaires for changes of voice, acoustics (fundamental frequency, jitter, shimmer, noise to harmonic ratio, voice intensity, vocal range), and aerodynamic (maximal phonation time, mean flow rate and subglottal pressure) analyses were done. RESULTS: The subjective voice symptoms after thyroidectomy were disturbances of high pitch, loud voice and singing voice, and easy fatigue at phonation. These voice symptoms were related to the extent of surgery. Vocal range was the only diminished parameter in acoustic and aerodynamic analyses after thyroidectomy. There were significant differences in jitter on acoustic and aerodynamic analyses between the strap muscle retraction group and the cutting group. CONCLUSION:Voice alteration after thyroidectomy without laryngeal nerve injury may be associated with the disturbance of the extralaryngeal skeleton- laryngotracheal fixation with impairment of vertical movement or by temporal malfunction of the strap muscles. These voice problems were related to the extent of surgery and cutting of strap muscles.

Vocal Dynamic Studies before and after Laryngeal Microsurgery / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Perceptual acoustic measures are most often used to judge the outcomes and the objective analysis of phonosurgical results before and after the microlaryngeal surgery. However, they have rarely been reported in this country. The purpose of this study is to analyze aerodynamic and acoustic results before and after microlaryngeal surgery and to analyze the differences of the prognosis of various benign vocal cord lesions. MATERIALS AND METHODS: At Inha University Hospital, from June 1996 to August 1998, 245 microlaryngeal surgeries were done. Malignant lesions were excluded. And 118 (54 females and 64 males) out of 245 patients were followed up after the surgery: the acoustic and the aerodynamic studies before and 8 weeks after microlaryngeal surgery for benign lesions: vocal polyp, vocal nodule, Reinke's edema, intracordal cyst and hyperkeratosis. Seven measurements were performed: fundamental frequency, jitter, shimmer, noise to harmonic ratio as the acoustic analysis, maximal phonation time, mean flow rate and subglottal pressure as the aerodynamic analyses. RESULTS: Postoperative acoustic and aerodynamic data of vocal polyp, vocal nodule, Reinke's edema and intracordal cyst were improved, but those of hyperkeratosis were not improved. CONCLUSION: By comparing the acoustic and aerodynamic data before and after the microlaryngeal surgery, postoperative vocal function was defined more accurately and objectively. Jitter, shimmer, and MFR might be meaningful parameters accessing the quantitative changes in vocal quality before and after the microlaryngeal surgery.