Harmonic Focus™ versus "knot tying" during total thyroidectomy: A randomized trial

The objective of the study is to compare the outcome of total thyroidectomy (TT) using the Harmonic FocusTM (HF) versus conventional ''knot tying'' (KT) in terms of operative time, parathyroid function and postoperative complications. This prospective study was designed with a random allocation of subjects using a drawing technique. Eighty-one consecutive patients were submitted to TT in 2010 and randomly divided into two groups: 43 patients operated using HF (HF group) and 38 patients operated using KT (KT group). Parathyroid function was evaluated by parathyroid hormone (PTH) level at 1 h postoperatively and calcium level at first post-operative day. Indications for medical therapy were PTH15 pg/ml and/or calcium8.0 mg/dl and/or clinical signs or symptoms of hypocalcemia. Main outcomes were operative time, PTH and calcium levels, need for medical therapy and post-operative complications. Mean operative time was significantly lower in HF group compared with KT group (100 ± 34 vs. 119 ± 30 min). There were no significant differences concerning transient hypoparathyroidism requiring calcium and/or vitamin D therapy: 17 patients (39.5%) in HF group versus 21 (55.3%) in KT group. Five patients (11.6%) in HF group experienced symptomatic hypocalcemia versus 6 (15.8%) in KT group, without statistically significant difference. No patients experienced recurrent nerve injury. HF is a new ergonomic, reliable device developed for thyroid surgery. According to our results, HF is a safe, time-saving alternative to ''knot tying'' thyroidectomy, with no influence on parathyroid function, medical therapy and nerve injury. © 2011 Springer-Verlag.