Surgical outcomes of different approaches to dissection of lymph nodes posterior to right recurrent laryngeal nerve: a retrospective comparative cohort study of endoscopic thyroidectomy via the areolar approach and via the axillo-breast approach

BACKGROUND: The American Thyroid Association (ATA) points out that lymph nodes posterior to right recurrent laryngeal nerve (LN-prRLN) should be routinely dissected. Due to the high risk of nerve injury, the lymph nodes in this area are difficult to dissect thoroughly. Although there are many approaches to endoscopic thyroidectomy, no study has been conducted on which one is more suitable. The purpose of this study was to evaluate the safety, thoroughness, related trauma, and feasibility of two widely used endoscopic thyroidectomy approaches, so as to provide a basis for the surgeon to select a better surgical approach. METHODS: This retrospective study included patients who underwent ETA (n=26) and ETAB (n=36). All patients had a pathological diagnosis of papillary thyroid carcinoma (PTC) and underwent endoscopic right thyroidectomy from May 2015 to February 2022 in the Affiliated Hospital of Nantong University. The basic clinical data and surgical outcomes of the two groups were compared. RESULTS: There was no statistical difference between the two groups in basic clinical data and oncological characteristics, which meant that the baseline data of the two groups of patients were comparable. Significant statistical significance was observed in the operation duration (149.38±44.15 vs. 119.22±45.48 min, P=0.011), drainage volume 24 h after operation (95.54±16.79 vs. 54.46±15.11 mL, P<0.001), visual analog score (VAS) 24 h after operation (3.69±1.44 vs. 2.25±1.32, P<0.001), hospitalization duration after the operation (3.19±0.75 vs. 2.25±0.44 days, P<0.001), number of lymph node dissections after right recurrent laryngeal nerve resection (0.96±1.08 vs. 2.06±1.77, P=0.007), and number of lymph node metastases after right recurrent laryngeal nerve resection (0.12±0.33 vs. 0.58±1.00, P=0.025). Besides, there was no significant difference in the numbers of central lymph node dissections and central lymph node metastases. CONCLUSIONS: Our study indicated that compared with ETA, ETAB may perform a more efficient dissection of the LN-prRLN based on less surgical trauma, which could provide a basis for the surgeon to select a better surgical approach.