Total endoscopic thyroidectomy versus conventional open thyroidectomy in thyroid cancer: a systematic review and meta-analysis

Background: Despite the considerable experience gained thus far using endoscopic technologies, the role of total endoscopic thyroidectomy (ET) for papillary thyroid cancer (PTC) remains controversial. We conducted a systematic review and meta-analysis to investigate the safety and effectiveness of total ET compared with conventional open thyroidectomy (OT) in PTC. Methods: A systematic search was conducted using the PubMed, Embase and Cochrane Library electronic databases up to March 2018. The quality of included studies was evaluated using the Newcastle-Ottawa Scale. Review Manager software version 5.3 was used for the meta-analysis. Results: Twelve studies including 2,672 patients were ultimately included in the systematic review and meta-analysis. ET was associated with longer operative time (P < 0.00001), drainage time (P < 0.00001) and hospital stay (P=0.03), higher transient recurrent laryngeal nerve (RLN) palsy rate (P=0.004) and a greater amount of drainage fluid (P < 0.0001) compared with OT. Furthermore, no significant differences were detected between ET and OT in terms of retrieved lymph nodes (P=0.17), blood loss (P=0.22), transient hypocalcemia (P=0.84), permanent hypocalcemia (P=0.58), permanent RLN palsy (P=0.14), hematoma or bleeding (P=0.15) and seroma (P=0.54). In addition, the rates of tumor recurrence were comparable (P=0.18), whereas the proportions of stimulated thyroglobulin levels <1 ng/mL measured after completion of thyroidectomy and radioactive iodine therapy were less (P=0.02) in the ET than in the OT group. Conclusion: ET is not superior to OT in terms of operation and drainage time, amount of drainage fluid, hospital stay or transient RLN palsy, but is comparable to OT in terms of retrieved lymph nodes and permanent complications. Despite the similar tumor recurrence rates between the two approaches, the level of surgical completeness in ET may not be as good as that for OT.