The thyroid is one of the largest endocrine glands in humans. Blood flow through the gland is approximately 8 ml/100 g/s and it may double in hyperthyroid states (16-17 ml/100 g tissue/s). Thus, the thyroid is the best blood-supplied organ in our body. The development of operative techniques in endocrine surgery, and especially in thyroid surgery, was for many years limited by the need to achieve appropriate hemostasis. Intraoperative and postoperative bleeding frequently led to serious consequences, from immediate reoperation to severe damage of vitally important structures, such as laryngeal nerves and parathyroids. Such complications were predominantly the consequence of inappropriate identification of thyroid-surrounding tissues and lack of care to perform atraumatic tissue dissection. Traditional thyroidectomy based on blood vessel ligation using ligatures or vascular clips became a time-consuming procedure, associated with a risk of postoperative bleeding. Unfortunately, the technique also restricted the development of minimally invasive operations, where pain reduction and good cosmetic effects were achieved. Procedures performed in a small surgical field were limited by technical capabilities. The introduction of bipolar pincers allowed for safe coagulation of small blood vessels; nevertheless, surgery continued to pose a grave risk of lateral thermal damage of the nerves and parathyroids while dissecting the thyroid.
At the end of the 20th
century, a new device was introduced to operating theatres, namely the ultrasonic scalpel, which ideally reconciled the need of appropriate hemostasis with atraumatic tissue dissection. The effect exerted by the shears on the tissue can be basically divided into three periods, depending on three different physico-chemical phenomena, namely coaptation, cavitation and coagulation, occurring with the temperature curve increasing in time. This allowed for sealing blood vessels with a diameter as small as 5 mm without a need for additional protection by ligation, thus significantly shortening operative time and decreasing the use of material (sutures, clips). The first complete report based on randomized studies on the use of the ultrasonic shears in thyroid surgery was prepared by Voutilainen et al
., based on a small group of patients. Of 36 individuals, the authors selected 19 and subjected them to procedures performed using the harmonic scalpel, noting a mean decrease of operative time by 35 min. The results were concordant with other publications presenting randomized studies of surgical patients [5
]. A decreased operative time both for unilateral lobectomies and for minimally invasive video-assisted total thyroidectomies (MIVAT) was also observed by the team headed by Professor P. Miccoli. Initially, the too small group of patients in whom the ultrasonic shears were employed (only 26 of 116 individuals included in the study) did not allow for a firm opinion on the advantages and disadvantages of the new instrument [2
]. Nevertheless, the subsequent reports published by Professor Miccoli's team (833 patients) unambiguously confirmed a significant decrease in operative time to the mean value of 36 min for lobectomies and 46 min for thyroidectomies, combined at the same time with a low rate of permanent complications: unilateral palsy of the recurrent laryngeal nerve in 7 patients (0.8%) and fixed hypoparathyroidism in 2 individuals (0.3%) [3
The use of the ultrasonic scalpel significantly decreased blood loss. Numerous randomized trials that focused both on open technique and on video-assisted procedures performed in simple and hyperthyroid goiter (Graves disease) reported a decrease of intraoperative blood loss with a simultaneous reduction of postoperative drainage [4
The problem of permanent paralysis of vocal cords and hypoparathyroidism occurring in procedures performed using the ultrasonic scalpel was reflected in numerous publications. The reports of Marcesi et al
. and Voutilainen et al
. and the commentary written by Professor Dionigi [10
] presented the dangers and consequences resulting from using the instrument, whose thermal effect on the laryngeal nerves and parathyroid glands had not been fully elucidated. The papers emphasized an increased incidence of such complications, which resulted from the lateral thermal effect of the scalpel tip on vitally important structures. The above-mentioned concerns were not supported by numerous randomized studies [16
], the authors of which stressed that although the new instrument was very useful in tissue preparation and dissection with simultaneous coagulation, the surgeon was not released from the obligation to correctly and safely identify the surrounding tissues; nor was he allowed to carelessly use the new shears in the close vicinity of the nerves and parathyroid glands. Incidentally, the above words of caution should not refer only to the harmonic scalpel, but also to traditional methods of vessel coagulation [23
The new tip of the ultrasonic shears – HARMONIC FOCUS – introduced in 2008 is a new generation instrument; its curved tip allows for simultaneous dissection, coagulation and division of tissue structures, at the same time making it possible to safely seal blood vessels of a diameter as small as 5 mm. The surgical experience acquired to date in using the ultrasonic scalpel (HS CS-14C and HS ACE-14S tips) [9
] and the proven benefits, presented in the literature, resulting from using the instrument prompted the present authors to introduce the new generation ultrasonic scalpel while performing open thyroidectomies. The above quoted data derived from the literature on the currently used harmonic scalpel tips were fully confirmed in the results of the study of a randomized group of patients. The skills and experience acquired to date by the surgical team in using the ultrasonic shears have markedly facilitated the use of the Harmonic Focus tip in nodular goiter surgery.
It should be emphasized that in the two investigated groups of patients, both the operative time and blood loss were statistically lower in the Harmonic Focus group. Both the thyroid volume and the character of nodular lesions in the thyroid parenchyma of the 2 patient groups were comparable. A decreased operative time was observed in the HF-G group, the drop amounting to approximately 30% as compared to the CL-G group. At the same time, intraoperative blood loss decreased by approximately 47%. No statistical differences were noted in the number and quality of postoperative complications. Postoperative drainage was not employed routinely in all the patients; only a single patient demonstrated subcutaneous edema combined with exudate, which was drained postoperatively. No statistical inter-group differences in duration of hospitalization were noted. While analyzing economic benefits in particular groups, the authors observed a decrease in the total cost of the procedure of total thyroidectomy in patients with nodular goiter operated on using the ultrasonic scalpel. The mean total cost of the procedure (expressed in EUR and adjusted for Polish conditions) was lower by approximately 50-60 EUR in patients operated on using the ultrasonic shears. In the opinion of the present authors, both the reduction of operative time and lower (however slightly) costs of the procedure combined with a better use of the operating theater would significantly contribute to shortening the surgery waiting list, at the same time reducing the costs of operation. Very similar conclusions were presented in other publications on the subject. The reports of Ortega et al
., Barczyński et al
., and Lombardi et al
] that focused on randomized groups of patients treated surgically for thyroid diseases not only demonstrated the above difference in operational time, but also a real decrease of the total costs of hospitalization.
In summary, the harmonic scalpel has become an instrument that can be used in all soft tissue procedures. It has allowed for simultaneous hemostasis, tissue preparation and a low-temperature effect on adjacent structures. More than 10 years of experience in employing the scalpel have provided us with strong arguments for advocating its wide use. Its effectiveness has been unambiguously proven in thyroid surgery, both in minimally invasive (video-assisted) and in open thyroidectomies.