Predictors of the difficulty of transcervical subcarinal lymph node dissection for esophageal cancer

BACKGROUND: Transmediastinal radical esophagectomy (TME) is a new minimally invasive approach without thoracotomy. However, the transcervical dissection of subcarinal lymph nodes (SCLN) is challenging. The shape or narrowness of the mediastinal space, particularly around the aortic arch to the tracheal bifurcation, may increase the difficulty of this procedure. The present study aimed to clarify predictors of the difficulty of transcervical SCLN dissection. METHODS: Patients who underwent TME between 2016 and 2019 were included (n = 126). Four indicators, the cervical angle, carina distance, aorta distance, and sternum distance, were defined as indicators of mediastinal narrowness by 3D-CT. The relationships between the difficulty of transcervical SCLN dissection and clinicopathological features, including the above indicators, were investigated. RESULTS: In a univariate analysis, the cervical angle (p = 0.023), aorta distance (p = 0.002), and middle thoracic tumor (p = 0.040) correlated with difficulty. The median cervical angle and aorta distance were 15° and 33 mm in difficult cases and 19° and 43 mm in easy cases, respectively. In a multivariate analysis, the short aorta distance (odds ratio: 7.96, p = 0.002) and middle thoracic tumor (odds ratio: 3.35, p = 0.042) were independent predictive factors. CONCLUSIONS: The cervical angle, aorta distance, and middle thoracic tumor may predict the difficulty of transcervical SCLN dissection. In difficult cases, a transhiatal approach should be combined for complete SCLN dissection.