Evaluation of subcarinal lymph node dissection and metastasis in transmediastinal radical esophagectomy

Relevance of Subcarinal Lymph Node Dissection for Gastroesophageal Junction Adenocarcinoma

INTRODUCTION

Reported rates of subcarinal lymph node (LN) metastases for esophageal carcinoma vary from 20% to 25% and the relevance of subcarinal lymph node dissection (LND) for gastroesophageal junction (GEJ) adenocarcinoma is poorly defined. This study aimed to evaluate rates of subcarinal LN metastasis in GEJ carcinoma and determine their prognostic significance.

METHODS

Patients with GEJ adenocarcinoma undergoing robotic minimally invasive esophagectomy from 2019 to 2021 were retrospectively assessed within a prospectively maintained database. Baseline characteristics and outcomes were examined with attention to subcarinal LND and LN metastases.

RESULTS

Among 53 consecutive patients, the median age was 62, 83.0% were male, and all had Siewert type I/II tumors (49.1% and 50.9%, respectively). Most patients (79.2%) received neoadjuvant therapy. Three patients had subcarinal LN metastases (5.7%) and all had Siewert type I tumors. Two had clinical evidence of LN metastases preoperatively and all three additionally had non-subcarinal nodal disease. A greater proportion of patients with subcarinal LN disease had more advanced (T3) tumors compared to patients without subcarinal metastases (100.0% versus 26.0%; P = 0.025). No patient with subcarinal nodal metastases remained disease free at 3 y after surgery.

CONCLUSIONS

In this consecutive series of patients with GEJ adenocarcinoma undergoing minimally invasive esophagectomy, subcarinal LN metastases were found only in patients with type I tumors and were noted in just 5.7% of patients, which is lower than historical controls. Subcarinal nodal disease was associated with more advanced primary tumors. Further study is warranted to determine the relevance of routine subcarinal LND, especially for type 2 tumors.

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.

Value of subcarinal lymph node dissection in esophageal cancer surgery: A case-control study

We investigated the value of subcarinal lymph node dissection in esophageal cancer surgery. Altogether, 240 patients with esophageal cancer admitted to our department between June 2012 and January 2016 were prospectively assigned to an experimental group (subcarinal lymph node dissection group, n = 120 cases) and a control group (uncleaned group, n = 120 cases). The number of subcarinal lymph nodes and the rate of subcarinal lymph node metastasis were determined, and the factors influencing subcarinal lymph node metastasis were analyzed using logistic regression in the experimental group. The operation time, postoperative complications, intraoperative blood loss, postoperative hospital stay, total postoperative hospital cost, and 5-year survival rate were compared between the 2 groups. In the experimental group, an average of 6.03 subcarinal lymph nodes were dissected, and the lymph node metastasis rate was 18.33%. The subcarinal lymph node metastasis rate in the experimental group was related to the size of the subcarinal lymph nodes, depth of tumor invasion, and tumor location. The 5-year survival rate was higher in the experimental group than in the control group (44.2% vs 30.0%, χ2 = 6.407, P = .04). The subcarinal lymph node metastasis rate in patients with esophageal cancer is high. Patients with mid-thoracic esophageal cancers that infiltrate beyond the esophageal muscle layer with subcarinal lymph node size > 1.0 cm should undergo lymph node resection, despite increased operation time, incidence of postoperative pulmonary infection, hospitalization time, and total postoperative cost; lymph node resection may improve the 5-year survival rate.