Window resection of the trachea and secondary reconstruction for invasion by differentiated thyroid carcinoma

In cases of differentiated thyroid carcinoma, the presence or absence of invasion into the circumferential organs is an important prognostic factor. Surgical procedures include circular resection of the trachea with end-to-end anastomosis and window resection with secondary closure. We have used window resection with secondary closure since 1993, and herein retrospectively analyze the treatment outcomes for this surgical procedure in order to determine the indications for procedure selection.

Subjects comprised 41 cases of invasion by differentiated thyroid carcinoma into the trachea, for which surgery was performed at the Department of Head and Neck Surgery of the National Cancer Center Hospital East from 1993 to 2007. The mean age was 65.7±7.9 years, and the median length of the observation period was 43 months. There were 17 cases (41.4%) cases of secondary relapse.

The 5-year and 10-year overall survival rates for this surgical procedure were 78.9% and 74.5%, respectively, while the 5-year and 10-year local control rates were 92.4% and 73.4%, respectively. The pathological resection stump was positive in 27 cases (65.8%), but no significant differences in treatment outcome were observed between the stump-positive group and the stump-negative group. There were 26 cases in which closure of the tracheal fistula was performed by the time of observation. When the tracheal defect had a diameter equivalent to 7 rings of the trachea or less and a circumference half that of the tracheal cartilage or smaller, including partial cricoid cartilage, it was possible to perform closure with only a local flap. For larger defects, reconstruction was performed using hard tissues or materials, such as hydroxyapatite, titanium mesh, and costal cartilage. There were 2 cases that required re-window because of dyspnea after closure.

The treatment outcomes for this surgical procedure for invasive cases of differentiated thyroid carcinoma into the trachea resulted in a low rate of local recurrence and similar survival rates as described in other reports. Even for cases of resection exceeding half the circumference of the trachea, closure of the tracheal fistula can be performed using hard tissues or materials; however, in such cases, we believe that closure should be attempted progressively in a two-stage reconstruction.