Tracheal window resection and reconstruction via sternocleidomastoid flap for invasive thyroid carcinoma

Abstract

 

OBJECTIVES

The aim of this study was to present surgical techniques and evaluate outcomes of a sternocleidomastoid muscle (SCM) myoperiosteal flap used for the reconstruction of tracheal or laryngotracheal defects after the radical resection of invasive thyroid carcinoma.

METHODS

A retrospective study was performed for patients at Peking Union Medical College Hospital from January 2008 to December 2018 of papillary thyroid carcinoma with tracheal or laryngotracheal invasion. Patients were enrolled only when they received window resection and reconstruction via an SCM myoperiosteal flap. The primary outcome was a stable airway, and the secondary outcome was survival.

RESULTS

A total of 15 invasive thyroid carcinoma patients were enrolled in this study. Laryngotracheal and tracheal reconstruction were performed in 11 and 4 patients respectively, with a median vertical defect of 3.5 cm (3.0, 4.5). A stable airway was achieved in 14 patients postoperatively. One patient experienced tracheal stenosis and received a second operation of tracheal sleeve resection and end-to-end anastomosis 105 days after the first operation. Tracheostomy was conducted in 5 out of 15 patients in whom the vertical defects were larger than 4 cm, and the tubes were extubated after a median time of 56 days (32, 84). The median observation time was 55 months (48, 86), and all 15 patients achieved a stable airway and showed no evidence of local recurrence at the end of follow-up.

CONCLUSIONS

For thyroid carcinoma with tracheal or laryngotracheal invasions, window resection with the SCM myoperiosteal flap reconstruction presented positive results in terms of a stable airway as well as oncological outcomes. The SCM myoperiosteal flap can be an appropriate reconstruction strategy, especially when the defects reach the thyroid cartilage.

Tracheal or laryngotracheal invasion, which is found in approximately 6% of primary thyroid carcinomas and 10% of recurrent thyroid carcinomas, is associated with life-threatening complications such as dyspnoea, asphyxia, dysphagia and bleeding [1].

INTRODUCTION

Tracheal or laryngotracheal invasion, which is found in approximately 6% of primary thyroid carcinomas and 10% of recurrent thyroid carcinomas, is associated with life-threatening complications such as dyspnoea, asphyxia, dysphagia and bleeding [1]. In addition, asphyxia has been shown to be the most common cause of disease-related death [2].

Radical resection is crucial for initial management of patients with differentiated thyroid carcinoma and provides the longest survival and the best palliation [3]. Tracheal or laryngotracheal resection followed by proper reconstruction methods are needed in cases with intraluminal airway invasion. Window resection is preferred when tumours are limited to the tracheal cartilage. In these cases, local muscle or perichondral flaps have been proved viable for the reconstructive strategy [4]. However, when the defects include cricoid cartilage, especially when the upper boundary reaches the thyroid cartilage, reconstruction of a laryngotracheal defect is usually a challenge.

This study describes surgical techniques using the sternocleidomastoid muscle (SCM) myoperiosteal flap for the reconstruction of tracheal or laryngotracheal defects and evaluates the surgical and oncological outcomes in 15 invasive papillary thyroid carcinoma patients.

PATIENTS AND METHODS

Study participants

This study included patients with papillary thyroid carcinoma involving tracheal or laryngotracheal invasions who underwent window resection and reconstruction using the SCM myoperiosteal flap at Peking Union Medical College Hospital between January 2008 and December 2018. The window resection was limited to a region involving up to half of the cartilaginous circumference. Patients were excluded if they had any of the following: histopathological diagnosis other than papillary thyroid carcinoma, surgery without reconstruction (e.g. shave excision), reconstruction with other methods (e.g. end-to-end anastomosis after tracheal sleeve resection) or were lost to follow-up. The study was conducted in accordance with the Declaration of Helsinki. A signed consent form for this study was obtained from each participant, and the study protocol was approved by the Peking Union Medical College Hospital Ethics Committee at 4 January 2021 (Protocol No. XH202100081).

Clinical parameters

Participant data including sex, age, treatment, and prognosis were extracted from medical records. The TNM classification followed the American Joint Committee on Cancer's Cancer Staging Manual 8th edition and recurrent disease was marked as rTNM [5]. Laryngotracheal or tracheal invasions were staged according to the classification by Shin et al. [6]. The operative parameters included defect site and size. Extubation time was recorded if a tracheotomy was performed. The postoperative parameters consisted of complications related to surgery, airway status and disease status at the end of the observation time.

Surgical techniques

The size of the window resection was evaluated following fibrolaryngoscope and imaging findings preoperatively and was determined by a visible tumour invasion intraoperatively. Parts of the cricoid cartilage and thyroid cartilage were resected along with the tracheal wall in some cases. Intraoperative frozen section analyses were used to secure peripheral surgical margins free of cancer before reconstruction. Reconstruction was carried out by preparing a vascularized myoperiosteal flap from the clavicle. The initial incision was made at the antero-inferior (about 4 o'clock position). After cutting through the periosteum to bone, the flap was elevated towards the postero-inferior (about the 7 o'clock position). Lateral cuts were made as the flap was elevated. The size of the myoperiosteal flap was should be kept larger than the defect. The SCM muscle was carefully dissected to permit just enough mobility for the flap to reach the defect without tension. With minimal dissection, the blood supply to the SCM muscle (transverse cervical, superior thyroid and occipital vessels) could be preserved to maintain vascularization. Tracheostomy was performed in a separate neck incision for some large defect reconstructions. Fibrolaryngoscopes were taken for the assessment of lumen stability and anastomosis condition immediately after the operation.

Patient follow-up

Airway status, local or distant recurrence and death due to disease or other reasons were recorded as study end points. The patients underwent follow-up until an outcome of interest had occurred. Due to the small sample size, only descriptive statistics are presented.

RESULTS

Patient characteristics and clinical parameters are summarized in Table 1. A total of 15 patients were enrolled in this study including 9 with primary thyroid carcinomas and 6 with recurrent disease. The median age of this cohort was 54 years (46, 64). Most patients had a Shin stage III or IV tumour except one with stage II. Histopathological examination showed classical papillary thyroid carcinoma in 13 patients and 2 with a follicular variant of papillary thyroid carcinoma. Laryngotracheal and tracheal resection with 0.5–1 cm margin were performed in 11 and 4 patients, respectively, with a median vertical defect of 3.5 cm (3.0, 4.5).

Table 1:

Clinical features of fifteen enrolled cases

Pat. no.	Gender (F/M)	Age (years)	TNM or rTNM stage	Shin stage	Type of TC	Site of defect	Defect (cm)	Tracheotomy (exbutation time)	Airway status	Survival outcomes	Follow-up (months)
1	M	46	T4aN1aM0	II	CPTC	Tracheal	2.0	No	Normal	Alive, NED	39
2	M	39	T4aN1bM0	III	CPTC	Laryngotracheal	3.0	No	Normal	Alive, NED	54
3	M	28	T4aN0M0	III	CPTC	Tracheal	2.5	No	Normal	Alive, NED	86
4	F	51	T4aN1bM0	IV	FVPTC	Tracheal	3.5	No	Normal	Alive, NED	152
5	M	76	T4aN1aM0	IV	CPTC	Laryngotracheal	3.5	No	Normal	Alive, NED	31
6	F	55	T4aN1bM0	III	CPTC	Laryngotracheal	3.0	No	Normal	Alive, NED	102
7	F	61	T4aN1bM0	III	CPTC	Laryngotracheal	2.6	No	Normal	Alive, NED	48
8	F	64	T4aN1bM0	III	CPTC	Laryngotracheal	3.2	No	Normal	Alive, NED	50
9	M	67	T4aN1bM0	III	CPTC	Tracheal	3.6	No	Normal	Death with cardiovascular disease	93
10	M	42	rT4aN1aM0	IV	CPTC	Laryngotracheal	6.0	Yes (56 days)	Normal	Alive, pulmonary metastasis	56
11	F	48	rT4aN0M0	IV	CPTC	Laryngotracheal	4.5	Yes (21 days)	Normal	Alive, NED	26
12	F	59	rT4aN1bM0	III	CPTC	Laryngotracheal	4.2	Yes (63 days)	Normal	Alive, NED	55
13	M	68	rT4aN1bM0	IV	CPTC	Laryngotracheal	3.6	No	Normal	Alive, pulmonary metastasis	66
14	F	46	rT4aN1aM0	IV	FVPTC	Laryngotracheal	6.0	Yes (105 daysb)	Stenosis, normal after the second operation	Alive, NED	48
15a	M	54	rT4aN1bM0	IV	CPTC	Laryngotracheal	4.5	Yes (42 days)	Normal	Alive, NED	76

^aTypical case.

^bThe patient received tracheal sleeve resection and end-to-end anastomosis 105 days after tracheostomy.

CPTC: classical papillary thyroid carcinoma; F: female; FVPTC: follicular variant of papillary thyroid carcinoma; M: male; NED: no evidence of disease; Pat.: patient; TC: thyroid carcinoma.

Tracheostomy was performed in 5 of the 15 patients in whom the defects were larger than 4 cm in vertical length. The tubes were removed after a mean of 56 days (32, 84). One patient failed to extubate due to lumen stenosis after the reconstruction of a 6-cm laryngotracheal defect. A second laryngotracheal sleeve resection with end-to-end anastomosis was performed in this patient. The patient was alive without tracheal stenting or recurrence at the end of the follow-up period, 48 months after surgery. No anastomotic dehiscence or iatrogenic injury of recurrent laryngeal nerve paralysis occurred in any of the patients.

Follow-up was completed in all 15 patients with a median observation time of 55 months (48, 86). A total of 14 patients were alive at the end of their follow-up, of whom 12 were disease free and 2 had a pulmonary metastasis but without any local recurrence. One patient died of cardiovascular disease but showed no evidence of local or systemic recurrence at the end of follow-up.

Typical case presentation

A 54-year-old male patient previously had received radical thyroid resection and I¹³¹ therapy. Computed tomography 2 years after the prior surgery showed a 2.6 cm × 1.9 cm  × 3.2 cm neoplasm without obvious enhancement on the right thyroid bed with invasions of the 1st to 2nd tracheal rings and cricoid cartilage (Fig. 1). The fibrolaryngoscope showed limited movement of the right vocal cord and an invasive tumour in the right subglottic and tracheal region (Fig. 2). The T stage was classified as rT4a. Then, a bilateral type III modified radical neck dissection (II–VI regions) was performed. After completing the neck dissection, the tumour was resected en bloc along with full-thickness window resection of the invaded right recurrent laryngeal nerve, inferior segment of the right thyroid alar cartilage, partial cricoid cartilage and 1st to 3rd tracheal cartilages involving approximately 50% of the cartilaginous circumference. An SCM myoperiosteal flap was then utilized to conduct reconstruction of a 4.5 cm × 3.5 cm laryngotracheal defect (Fig. 3). Intraoperative fibrolaryngoscope showed the reconstructed laryngotracheal wall was stable (Fig. 4A). No anastomotic leakage, lumen stenosis or other severe complications occurred postoperatively. Ossification of the flap re-established the skeletal support of the tracheal wall 9 months later (Fig. 4B). No local or systemic recurrence was found at the follow-up 76 months after surgery.

Figure 1:

Computed tomography showed a neoplasm with invasions of trachea and cricoid cartilage. (A and B) Red thin arrows represent invasion of cricoid cartilage. (C and D) Red thick arrows represent invasion of the 1st to 2nd tracheal rings.

Figure 2:

A preoperative fibrolaryngoscopic evaluation showed that the tumour invaded the subglottic region and trachea.

Figure 3:

The SCM myoperiosteal flap was prepared for reconstructing the laryngotracheal defect. The black thick arrow represents the sternocleidomastoid muscle myoperiosteal flap; the black thin arrow represents the residual thyroid cartilage; the white thick arrow represents the residual cricoid cartilage; and the white thin arrow represents the residual 1st–3th tracheal cartilages.

Figure 4:

Airway status under the fibrolaryngoscope. (A) An intraoperative fibrolaryngoscope showed no leakage or stenosis of the reconstructed laryngotracheal wall. The white arrow represents the sternocleidomastoid muscle myoperiosteal flap used for the reconstruction of the laryngotracheal wall. (B) Fibrolaryngoscope 9 months after surgery. The black arrow represents the ossification of the flap which re-established the skeletal support of the laryngotracheal wall.

DISCUSSION

Thyroid carcinoma with tracheal or laryngotracheal invasions indicate more aggressive tumour behaviour, which was shown to have a significant influence on survival [7]. Radical resection is currently the prime objective for the treatment of the locally invasive thyroid carcinoma and provides the longest survival [8]. However, tracheal or laryngotracheal defect reconstruction after complete resection remains a challenge.

The surgical alternatives for these invasive thyroid carcinomas include tracheal shave resection, window resection and sleeve resection with end-to-end anastomosis [4]. Window resection is more applicable to localized disease of the tracheal cartilaginous circumference and is relatively simple and less traumatic than other surgical approaches. Following resection, reconstruction with a local SCM-based myoperiosteal flap provided stiffness and vascularity to the lumen wall and thus prevented airway collapse [9]. In addition, when invasions reach the thyroid cartilage, window resection followed by SCM-based myoperiosteal flap reconstruction was superior to other reconstructive methods. The pliable nature of the periosteal flap permits it to conform to the irregular edges of the defect to facilitate airtight closure [10, 11].

Airway stability was the focus of tracheal or laryngotracheal reconstruction. Prior studies have reported that window resection could be considered only for tumours involving up to about one-third of the tracheal circumference to avoid an unstable lumen [12, 13]. A study that included 12 cases showed a median resected vertical length of the trachea of 3.3 cm with the longest resection of 5 cm [13]. In our study, circumference resection was strictly limited to the anterior and laterally localized regions including less than half of the cartilaginous part, and the median vertical length of the defect was 3.5 cm with the longest resection of 6 cm. Within this range of resection, most patients enrolled in this study achieved positive results in a stable airway and oncological outcomes.

Some studies have suggested the T-tube for temporary stenting of the trachea during healing to achieve a stable airway [13–15]. However, an average of 68.1 days (range 7–313) or even longer was required for extubation, which was inconvenient to the patient [14]. For patients enrolled in this study, the laryngoscope was used to assess lumen stability and anastomosis condition immediately after surgery. All 15 patients showed a stable lumen without anastomotic dehiscence. There were 10 cases with a defect shorter than 4 cm in vertical length. Among them, tracheostomy or insertion of a T-tube was not performed, and all patients achieved a stable airway during the follow-up. To prevent potential dyspnoea caused by airway stenosis, tracheostomy instead of a T-tube was performed in 5 patients in whom the defect was >4 cm in vertical length. The tracheostomy tube was extubated successfully in 4 of them with a median time of 56 days (range 21–105). This was shorter than the reported extubation time of the T-tube. These findings indicated that airway stenting might not be required for some cases using this reconstructive method. Further studies with larger samples are needed to verify this result.

Limitations

Advantageous as window resection followed by reconstruction with an SCM myoperiosteal flap is, limitations still exist. It may not be applicable for disease located in the membranous part of the trachea [11, 12]. In addition, potential lumen stenosis after a large defect reconstruction added risks of dyspnoea and asphyxia [16]. The case of tracheal collapse and stenosis in our study was a female patient. The diameter of her trachea was small, and the horizontal defect reached one-half of the cartilaginous circumference. Moreover, scar diathesis was present during her process of anastomotic healing. All these factors could be adverse features for reconstructive lumen stability and should be considered fully in the surgical plans.

CONCLUSION

The SCM myoperiosteal flap provides a tracheal and laryngotracheal reconstruction strategy with feasible, pliant, airtight composite autologous graft and guarantee of blood supply. It may serve as an appropriate approach for some specific defects left by window resection, especially when the upper boundary of defects reached the thyroid cartilage.

Funding

This work was supported by the National Natural Science Foundation of China (grant number 81273173).

Conflict of interest: none declared.

Author contributions

Xin Xia: Conceptualization; Data curation; Formal analysis; Methodology; Writingvoriginal draft. Yonghua Cai: Data curation; Methodology; Writing—original draft. Xiaoli Zhu: Data curation; Methodology. Yingying Zhu: Data curation; Methodology. Le Shen: Data curation; Methodology. Yalin Zhou: Methodology. Wenwen Diao: Data curation; Methodology. Xingming Chen: Conceptualization; Data curation; Formal analysis; Writing—review & editing.

Reviewer information

Interactive CardioVascular and Thoracic Surgery thanks Shunsuke Endo, Mohamed Rahouma and Alper Toker for their contribution to the peer review process of this article.

ABBREVIATION

SCM

Sternocleidomastoid muscle