Analysis of various defects and reconstructive methods after invasive thyroid carcinoma resection.

[OBJECTIVE] The thyroid gland adjoins the trachea, pharynx, esophagus, carotid artery and cervical skin. Most thyroid carcinomas have been treated at lower stages; however, in some cases the carcinomas have invaded the surrounding organs. After resecting invasive thyroid carcinomas, the defects vary depending on the invasion area and organs affected; subsequent reconstructive methods vary depending on the size of defect and its components. This study analysed the pattern of defects and the reconstructive methods used following invasive thyroid carcinoma resection.

[METHODS] From April 2011 to March 2021, 665 patients in Saitama Cancer Center (Saitama, Japan) were diagnosed with thyroid carcinoma and subsequently underwent thyroidectomies. In the 25 patients (3.8%), the thyroid carcinoma invaded surrounding organs and any reconstructive surgery-including end-to-end tracheal anastomosis and simple pharynx closure-was performed after thyroid carcinoma resection. The patients' records were retrospectively reviewed, and the defects and subsequent reconstructive methods were analysed.

[RESULTS] When our new classification system was applied to the defects, the number of cases for each type was totaled: Tr0: 1; Tr1a: 3; Tr2b: 5; Tr3a: 1; La-Tr3b+PE2: 7; La-Tr3b+PE2+S2: 1; PE1: 1; PE1+S1: 2; S1: 2; S2: 2. For Tr0, a tracheal fenestration was performed after the tumor resection and the fenestration was closed with a hinge flap. For Tr1a defect, a tracheal fenestration was performed with cervical skin after the tumor resection and the tracheal fenestration was closed with a deltopectoral flap or pectralis major musculocutaneous flap. In one recent patient, the tracheal fenestration was reconstructed using free forearm flap and cervical skin, and the fenestration was closed with a hinge flap. For Tr2b defect, free forearm flap and costal cartilage graft reconstruction was performed after the tumor resection and the fenestration was closed with a hinge flap. For Tr3a defect, end-to-end anastomosis was performed in one patient. For La-Tr3b+PE2 defect, total pharyngolaryngectomy with free jejunal flap reconstruction was performed. For PE1 defect, a simple closure was performed in one patient and a PMMC muscle flap was used for covering the suture line in two patients. For S1 and S2 defect, PMMC flap or DP flap was used.

[CONCLUSION] Our analysis of defects and reconstructive methods defines the complex defect patterns occurring after invasive thyroid carcinoma resection, describes the patterns of subsequent reconstructive methods.