Discussion:
Involvement of airway has been reported in 6% - 21% of patients undergoing thyroid surgery [10-12]. Among patients with invasive DTC, 37% demonstrate tracheal invasion. Intraluminal tracheal involvement is less frequent, occurring in 0.5% - 1.5% [13-14]. While recurrent laryngeal nerve damage does not independently influence survival, esophageal and tracheal invasion has been shown to impact survival [15]. The complete resection of the trachea to remove neoplasm that does not invade the mucosa is controversial [16-17]. Partial tracheal involvement without mucosal invasion can be treated by partial resection and has a favorable outcome.However, a larger area of mucosal invasion may limit the feasibility of partial tracheal resection because it may lead to kinking or stenosis after repair. Hence full circumference resection and end to end anastomosis is preferred to shaving trachea. Although extensive involvement of the trachea like 6 or more tracheal ring and simultaneous invasion of the esophagus remains contradiction for the procedure. One of the major advantages of tracheal resection is the immediate and effective relief of intratracheal bleeding and the symptoms of obstruction. Hence in our opinion, trachea should be resected and anastomosed whenever needed for better short- and long-term outcome.
Conclusion: Thyroid cancer invading trachea is a rare entity in differentiated thyroid cancer. But in case of recurrent disease partial/ focal infiltration can be expected. Unfortunately, in this case, the thyroid cartilage infiltration was ≥3 cm invading the 3rd tracheal ring. Small resection of trachea is easy to perform but for of 3-4 cm defect only. Tracheal mobilization and hyoid are the method to bring together the cut ends to be anastomosed. This requires high degree of skill and utmost precaution of tracheal vascularity with intervention for further speech.
Conflict of Interest: The authors have stated explicitly that there are no conflicts of interest in connection with this paper.