Optimal extent of lateral neck dissection for well-differentiated thyroid carcinoma with metastatic lateral neck lymph nodes: A systematic review and meta-analysis

The purpose of this systematic review and meta-analysis was to determine the optimal extent of lateral neck dissection in patients with well-differentiated thyroid carcinoma with clinically confirmed lateral neck lymph node metastases. All studies reporting the distribution of metastatic lymph nodes in level IIb or level V, complication rate, recurrence rate, or clinical outcomes according to the extent of lateral neck dissection were collected from MEDLINE and Embase databases. Two reviewers independently retrieved articles, extracted data, and assessed the quality of the studies. A total of 40 criteria-meeting studies were included in the systematic review and meta-analysis, representing a total of 6 027 patients. The distribution of metastatic lymph nodes was 13.7% (95% confidence interval [CI]: 8.2-21.9%) in level IIb and 22.1% (95% CI: 18.6-26.1%) in level V. Shoulder syndrome complication showed a tendency to increase when comprehensive neck dissection was performed. The recurrence rate was 11.2% (95% CI: 8.4-14.9%) in the comprehensive neck dissection group and 11.0% (95% CI: 4.2-26.1%) in the selective neck dissection group. Clinical outcomes showed no difference between groups. In conclusion, selective neck dissection may be considered in patients with well-differentiated thyroid carcinoma with lateral neck lymph node metastases without any other risk factors.