Phonatory results after laser surgery for glottic carcinoma

Abstract

OBJECTIVE: To identify the influence of type and extent of surgery on postoperative voice parameters after endoscopic laser resection for glottic carcinoma. SETTING AND DESIGN: A multidisciplinary university-based head and neck cancer center. Objective and subjective measures of voice were correlated with type and extent of surgery following a standardized classification in a prospective study including 80 patients. SUBJECTS AND METHOD: The postoperative mechanism of phonation was assessed by videostroboscopy 6 months after surgery at the earliest. A phonetogram was produced, and its area was calculated (relative phonetogram [RP]) in relation to a gender-different normal phonetogram. Two speech therapists (ST) and a trained otolaryngologist (TO) rated each voice independently for communication ability in a grade from 1 (poor) to 5 (near normal). RESULTS: After simple cordectomy the means were as follows: RP = 24.8%, TO = 3.26, and ST = 3.33. When the anterior commissure was completely preserved, mean results were better (RP = 34%, TO = 3.92, ST = 3.83). Results were worse after extended cordectomy (RP = 14.7%, TO = 2.82, ST = 3.00) and transglottic resection (RP = 13.7%, TO = 2.30, ST = 2.86) but were similar within these two groups. The parameters RP, TO, and ST do not differ significantly between the group who had speech therapy after surgery ( n = 33) and the group who did not ( n = 47). Voice production at glottic level yields better results for every parameter than supraglottic substitute phonation. The amount of tissue removed was less significant. CONCLUSION: Postoperative phonatory results correlate with the postoperative mechanism of phonation. There is no linear correlation with the amount of tissue removed. Comparison of similar types of resection preservation of the anterior commissure plays a key role. From the data in this study, there is no evidence for a significant benefit from speech therapy. The parameter RP is an effective and relatively simple parameter to complete auditory voice assessment.