Discussion

Xu et al8 mentioned that stenosis of the glottis could influence both phonation and respiration. Matrka9 recommended surgery of the anterior glottic webs for air restriction or symptomatic dysphonia. The chief complaint of our patient was hoarseness, and Hirano et al10 reported that the vocal process divides the glottis into two parts. The area of the anterior glottis is from the anterior commissure to the vocal process. The area of the posterior glottis is from the vocal process to the posterior wall of the larynx. The function and histology of the anterior glottis are phonation and stratified squamous epithelium. The function and histology of the posterior glottis are to maintain the airway and pseudostratified epithelium as one type of respiratory epithelium. Therefore, the pathophysiological differences depend on the location of the glottic adhesions. Our case was anterior glottis web and the chief complaint was hoarseness. The main symptom of the posterior glottis web would be a respiratory problem.

Sato et al11 described that anterior glottic webs are two types. One type is a laryngeal diaphragm which shows a web-like formation with adhesions including the anterior commissure. The other type is a bridge-like adhesion in the anterior glottis. Our case would correspond to the former laryngeal diaphragm type. The tissues of the glottic web showed inflammation with granulation and fibrotic scars, regardless of the causes.7 Our histopathological findings revealed the anterior glottic web with squamous cell carcinoma and granulation formations in the background. The mechanism would be considered continuous inflammation of the vocal cord cancer resulting in the formation of granulation and scarring. Cases with readhesion of the anterior glottis after operation have been reported. Hirayama et al5 performed laryngomicrosurgery in 6 cases with anterior glottic web and 4 cases experienced readhesion of the anterior glottic postoperatively. In order to prevent readhesion after cutting the anterior glottic web, Figi7 and Adachi12 suggested skin graft and fibrin coating for the wound after cutting the web. Umeno et al13 Chen14 Paniello15 and Edwards16 tried using a silicone tube and stent or keel placement. Xu et al8 described mucosal suturing of the vocal fold with placement of a stent. However, most reports including those above that were concerned with protective methods for postoperative readhesion in the anterior glottis web did not discuss the success or recurrence after a long-term follow-up. Veen17 reviewed mitomycin C in the aerodigestive tract in human studies and the follow-up period in 27 of 32 references was within 2 years or not reported. Our case was cancers of bilateral vocal cords with an anterior glottic web. Postoperative radiation therapy was administered without protective methods to prevent postoperative readhesion. After radiation therapy, we did not add it, because such methods would prevent us from determining whether there was a recurrence of anterior glottic web and glottic cancers.

Some hospitals18 19 have reported the results of CO₂ laser cordectomy for gottic cancer. However, CO₂ laser therapy for wide lesions with bilateral vocal cords including web would worsen the dysphonia and increase the possibility of readhesion of the postoperative wounds. Therefore, we did not select CO₂ laser. Our patient underwent laryngomicrosurgery to remove laryngeal cancer tumours, and to cut-off and remove the anterior glottic web.

This simple resection and the postoperative radiotherapy showed no recurrence of the glottic carcinomas and no readhesion of anterior glottis. The reason would be considered the complete disappearance of residual cancer in the bilateral vocal cords and web by radiotherapy and re-epithelialisation of the wounds. Histopathological examination revealed the diagnosis as laryngeal carcinoma T1bN0M0. For early stage laryngeal carcinoma, radiotherapy is recommended.20–23 Moreover, since the histopathological findings in our case showed surrounding infiltration of the cancer, we considered the possibility of residual laryngeal cancer. Therefore, we administered radiation therapy (66 Gy) postoperatively. In Japan, Harada et al20 retrospectively studied the 5-year local control rates of radiotherapy for early glottic cancer (T1-T2N0) and revealed 92% in T1a, 83% in T1b (as in our case) and 86% in T2. In other countries, Zouhair et al22 described that the 5-year overall, cancer-specific and disease-free survival after radiation therapy alone in the early-stage were 80%, 94% and 70%, respectively. Jones et al23 discussed that radiotherapy and surgery for early laryngeal cancer (T1-T2 N0) were matched. The methods of the surgery included horizontal or vertical partial laryngectomy and cordectomy. The 5-year tumour-specific survival after radiotherapy and surgery were 87% and 77%. He concluded that both radiotherapy and surgery were equally effective for early laryngeal cancer. Speech and voice of the patients treated by radiotherapy were significantly better than those treated by surgery. At present, our patient has no recurrence of glottic carcinomas and no readhesion in the web region one and a half years since the end of radiotherapy. His hoarseness has completely improved. We need to continue follow-up for at least 5 years to determine whether readhesion anterior glottic web or glottic cancer has recurred.