BackgroundLigaSure® Small Jaw (LSJ) has been recently introduced as an energy-based vessel sealing device, which has provided better intraoperative and postoperative outcomes in thyroidectomies, compared to conventional technique. In the current study, we aimed to examine the efficiency of hand-sewn and LSJ thyroidectomy, based on operation time and perioperative complications.MethodsAll patients with the diagnosis of multinodular goiter, thyroid cancers, retrosternal goiter and other indications for thyroid surgeries, enrolled. Of 550 patients, 261 patients randomly assigned to the conventional group (A) and 274 patients to LigaSure Small Jaw group (B). Study groups compared concerning operative time, recurrent laryngeal nerve (RLN) injury, hypocalcemia, and postoperative complications.ResultsThere was no significant difference regarding demographic data between groups A and B. During total thyroidectomy, intraoperative blood loss was 64.42 ± 20.72 ml and 49.64 ± 17.92 ml in groups A and B, respectively (P 0.043). Operative time was significantly lower in LSJ group compared to the conventional group in total and subtotal thyroidectomy (P 0.002; P 0.001). Three patients who underwent conventional total thyroidectomy had RLN palsy. However, there was no significant difference between techniques regarding RLN injury (P 0.134).Postoperative total and ionized serum calcium levels decreased compared to preoperative levels in both conventional and LSJ technique; however, changes in total and ionized serum calcium were more severe in patients with conventional thyroidectomy (total calcium, P < 0.0001) (ionized calcium, P 0.005).ConclusionThe LigaSure Small Jaw device decreases operative time and intraoperative bleeding compared to conventional technique. Besides, changes in total and ionized calcium levels in patients with LSJ thyroidectomy are subtle compared to HS technique.Trial registrationRegistered in Iranian Registry of Clinical Trials (www.irct.com), trial registration: IRCT2014010516077N1, Registered: 23 May 2014).