Many published, comparative and observational, studies have variably reported some significant advantages in terms of operative time [16, 23–25], complications rate [26, 27], and reductions in incision size [25, 27–29] with the use of HS (ultracision or focus) respect to the conventional techniques, as clamp-and-tie in thyroid surgery [30].

In our previous study, in 2008, besides confirming that HS utilization during total thyroidectomy allows for a significant reduction in operative time (about 30 %) when compared with the conventional CT technique, we extensively analyzed the influence of this element on costs; the authors assert that, since time spent in the operating room is expensive [31], this would counterbalance the cost of the HS hand piece and eventually result in a overall cost saving. The significantly higher cost of disposable materials in the HS group was counterbalanced by significant higher costs of drugs, personnel and operative room charges in the CT group related to the longer operative time, and operative room utilization time. Nonetheless, the shorter operative time implies the possibility to treat more patients in the same operative sessions. One could anticipate that with the utilization of the HS, surgeons could perform one conventional total thryoidectomy more every three or four procedures. This could mean at least one operation more for each operative session. Ultimately, this could result in a better utilization of health resources and, above all, in a potential significant reduction of the waiting list, which, at least in our health system, has a crucial role. Another potential additional advantage of the use of HS and consequent avoidance of manual tying could be the possible reduction of human resources in the operating room. In other words, surgeons could theoretically accomplish thyroidectomy without any assistant [30].

In 2010, Miccoli et al. conducted a randomized controlled trial about the utilization of Harmonic FOCUS compared to standard CT technique in thyroid surgery. They found a significant reduction of operative time in the FOCUS group (33.4 vs. 47.2 min). They assert that the significant reduction rate of operative time occurred because the FOCUS shears allow not only coagulation and cutting the vessels but also the dissection of planes without requiring any further tools; furthermore, the very low occurrence of failures in the hemostatic division of vessels (both veins and arterials) avoids the use of manual ligatures or clips, which is time consuming. One of the most important advantages of this instrument is the very rare occurrence of delayed bleeding [32]. In this study, a significant difference in the drainage output between the two groups in favor of the FOCUS group was observed. Postoperative pain was significantly lower after 12 h and also after 24 h. The explanation for such a significant difference might be found in the shorter operative time, the reduction of neck hyperextension due to the easier access to the upper pedicle [32], and consequent reduced stretching of the wound. Others also note that edema of the tissues is reduced because of the much lower temperature reached by the Harmonic shear [22, 33].

In 2008, Cirocchi et al. conducted a systematic review and meta-analysis to compare the surgical effectiveness of HS vs. CT in total thyroidectomy in patients with thyroid benign and/or malignant pathologies. They observed that the main significant advantages of HS are shorter operative duration, lower intraoperative blood loss, and lower overall drainage volume.

In this analysis, the reduction of operative time has the advantage to reduce significantly the costs of utilization of operating room. The cut and coagulation functions permit also to reduce lymphorrea depending on ligations and sections and the authors deduce that this leads to the opportunity of anticipated discharge and subsequent reduction of costs of permanence in the hospital.

The incidence of postoperative complications is similar in two groups (transient laryngeal nerve palsy, permanent laryngeal nerve palsy, transient hypocalcemia, permanent hypocalcemia) [34].

A meta-analysis conducted in 2010 by Ecker et al. confirmed the impact of the HS on operating time, with a reduction of nearly 25 % when compared with all other hemostatic methods. With regard to postoperative pain, the data show that patients in the harmonic scalpel group had a significantly less painful postoperative course when compared with patients with suture/clip ligation plus electrocoagulation [35].

Also Melck et al., in a meta-analysis realized in 2010, showed that the utilization of the HS for total and subtotal thyroidectomy significantly reduced operative time compared to CT by greater than 23 min. Furthermore, there was a 31 % decreased risk of transient postoperative hypocalcemia with HS utilization and there was also no statistically significant difference in the risk of transient postoperative nerve damage between the two groups. Authors speculate that use of the HS may facilitate dissection of the parathyroid glands in a plane farther away from the parathyroid gland capsule, thus reducing the chance of damaging their blood supply, directly or indirectly, with either mechanical forces or electrical currents [36].