Background: The recurrent laryngeal nerve (RLN) lymph nodes are among the most frequently involved lymph nodes in esophageal cancer. Surgical removal of these lymph nodes is considered beneficial for postoperative prognosis, especially in patients with squamous cell carcinoma. Unfortunately, the precise surgical anatomy of the upper mediastinum is not well understood and no distinct high-resolution images are currently available.
Methods: In this article, we provide a simple intuitive concept of upper mediastinal surgical anatomy that could facilitate rational anatomical lymphadenectomy of the RLN lymph nodes. The essential concept of this mesenteric excision is to mobilize mesoesophagus including RLN in an en bloc fashion and to save RLN laterally by incising visceral sheath. This is applicable identically to both right and left upper mediastinum.
Results: Between January 2009 and December 2017, thoracoscopic esophagectomy with upper mediastinal lymphadenectomy for primary esophageal cancer was performed in 189 patients. Median thoracoscopic procedure time was 297 (range 205-568) min and median intraoperative blood loss was 70 ml (range unmeasurable up to 2545 ml). Median number of harvested upper mediastinal lymph nodes was 12. Postoperative complication of Clavien-Dindo classification grade III or higher events was observed in 14% of patients. RLN palsy of grade II or higher occurred in 20 patients (11%).
Conclusion: The mesoesophagus in the upper mediastinum is an anatomical unit surrounded by fibrous connective tissue containing the esophagus, trachea, tracheoesophageal vessels, lymphatic tissue, and RLNs. Thus, mesenteric excision of esophagus is defined to resect this area by sparing trachea and RLNs for rational anatomical lymphadenectomy. We believe that this concept makes upper mediastinal lymphadenectomy safer and more appropriate.
Keywords: Esophageal cancer; Mesenteric excision; Mesoesophagus; Recurrent laryngeal nerve; Squamous cell carcinoma; Visceral sheath.