Lymph node dissection along the recurrent laryngeal nerves in patients with oesophageal cancer who had undergone chemoradiotherapy: is it safe?

OBJECTIVES: Upper mediastinal lymph node dissection (LND)-especially along the recurrent laryngeal nerve (RN)-is the most challenging part of oesophageal cancer surgery. We investigated whether thoracoscopic RN LND may be safely performed in patients with oesophageal cancer who had undergone chemoradiotherapy (CRT). METHODS: Patients with oesophageal cancer who had undergone thoracoscopic RN LND (n = 103) were divided into 2 groups according to whether they had prior treatment with CRT or not [the CRT group (n = 65) vs the upfront surgery group (n = 38), respectively]. All patients were operated on by a single surgeon. Intergroup comparisons were made in terms of (i) the number of dissected nodes, (ii) rates of RN palsy and (iii) rates of perioperative complications. The learning curve for the RN LND procedure was investigated using the cumulative sum method. RESULTS: RN LND after CRT was more technically challenging when performed in the left side. Complete skeletonization of the left RN was achieved only in 66.2% of patients in the CRT group (vs 86.8% in the upfront surgery group; P= 0.022). The rate of postoperative left side RN palsy was significantly higher in the CRT group (26.6%) than in the upfront surgery group (7.9%, P= 0.022), albeit resulting in neither higher pneumonia rates nor longer hospital stays. The cumulative sum analysis revealed a steep learning curve for left RN LND in the CRT group. Unfortunately, an acceptable proficiency (left RN palsy rate: 15%) was not achievable even after treatment in 65 cases. CONCLUSIONS: Thoracoscopic RN LND is safe but poses significant challenges in CRT-treated patients.