Sternomastoid intermuscular approach has better postoperative cosmesis and less neck discomfort than linea alba cervicalis approach in hemithyroidectomy: a randomized clinical trial

BACKGROUND: Surgery is still the most important treatment method for thyroid cancer. The classic linea alba cervicalis approach caused obvious neck scarring. This study explored an alternative open operative approach with concealed incision for hemithyroidectomy, and demonstrated whether it was non-inferior to traditional approach in postoperative complications and operation efficiency. METHODS: Patients (n=220) from November 2019 to November 2020 willing to undergo hemithyroidectomy because of differentiated thyroid cancer were randomly divided into the sternocleidomastoid intermuscular approach (SMIA) group (n=110), and the linea alba cervicalis approach (LACA) group (n=110). The incidence of postoperative complications within 3 months and operation efficiency indicator R0 resection rate were recorded as primary endpoint, while scar apperance was assessed as secondary endpoint. The data were statistically analyzed. RESULTS: The baseline data of these two groups were comparable, with no significant difference (P>0.05). As primary endpoint, R0 resection rate was 100% in both groups. In the 1-month follow-up period, the SMIA group had a lower score for neck discomfort compared with that of the LACA group (1.01±0.1648 vs. 0.5657±0.0976, P=0.0217). The SMIA group’s scar had better results from the observer scar assessment compared to that of the LACA group as secondary endpoint. Within the 3-month follow-up, the total complications were calculated, and it was demonstrated that SMIA was non-inferior to traditional LACA operation (P of non-inferiority=0.0048). CONCLUSIONS: Compared with LACA group, surgery through the SMIA is safe, effective, and has non-inferior postoperative complications. SMIA can be considered an alternative approach to classic LACA in hemithyroidectomy.