[Analysis of long-term efficacy of CO₂ laser partial excision of vocal folds for 599 cases in the treatment of vocal cord leukoplakia]

Objective: To analyze long-term prognosis and influencing factors of recurrence in vocal fold leukoplakia treated by endoscopic cordectomy with CO₂ laser. Methods: A retrospective review was conducted on 599 patients with vocal fold leukoplakia [566 males and 33 females, aged 17-84 years (median age 55 years)], undergoing endoscopic cordectomy by CO₂ laser under general anesthesia at the Department of Otorhinolaryngology Head and Neck Surgery of Beijing Tongren Hospital, Capital Medical University, from January 2000 to December 2023. The study analyzed the clinical features, pathological grade, surgical methods, postoperative voice function, recurrence, malignant changes and analyzed the long-term efficacy and and its influencing factors. The patients were followed up for a duration of 6-249 months postoperatively, with a median follow-up time of 48 months. SPSS 20.0 software was used for statistical analysis. Results: Among the 599 patients, the histopathological grades included simple squamous cell hyperplasia in (n=264, 44.08%), mild dysplasia (n=96, 16.03%), moderate dysplasia (n=74, 12.35%), severe dysplasia(n=43, 7.81%), carcinoma in situ(n=35, 5.84%), and carcinoma in situ with microinvasion(n=87, 14.52%). The 3-year and 5-year overall recurrence rates were 12.91% and 16.00%, respectively. In patients with precancerous lesion, 3.91% of recurrences presented with an upgraded pathologic grade and 2.34% evolved into carcinoma. The risk of recurrence was higher in lesions involving the anterior commissure, larger lesions, significant reduction/absence of mucosal waves, neovascularization/suspected neovascularization, and pathology of dysplasia/carcinoma in situ/carcinoma in situ with microinvasion(F=44.76,21.54,11.55,8.78,23.20,respectively,P<0.05). Additionally, patients with recurrent disease exhibited higher reflux symptom index scores compared to those without recurrence. Exophytic lesion characteristics and the inability to cease smoking postoperatively were identified as independent risk factors for recurrence with an upgraded pathological grade, with odds ratios of 8.675 and 11.380 times greater than those with non-exophytic lesions and successful smoking cessation, respectively. At the 6-months postoperative assessment, patients who underwent subepithelial cordectomy (typeⅠ) demonstrated a statistically significant increase in fundamental frequency (t=-3.38, P<0.05), and while other voice acoustic parameters were not significantly different.Conversely, those who underwent transmuscular cordectomy (TypeⅢ) exhibited significant alterations in multiple voice acoustic parameters when compared to preoperative values (P<0.05). Furthermore, postoperative vocal fold adhesions developed in 84 patients with 13 of these individuals requiring surgical intervention for adhesion release. Conclusions: Lesions involving the anterior commissure, larger lesions, pathology of dysplasia/carcinoma in situ/carcinoma in situ with microinfiltration, significant reduction/absence of vocal fold mucosal waves, and neovascularization visible under NBI are indicative of an increased risk of recurrence, whereas exophytic lesions and the inability to cease smoking postoperatively significantly increase the risk of recurrence with elevated pathologic grade. Recovery of postoperative voice quality is procedure-dependent, underscoring the importance of surgical approach selection in the management of vocal fold leukoplakia.