IMPACT OF THE HARMONIC SCALPEL HEMOSTASIS IN TOTAL THYROIDECTOMY IN COMPARISON WITH CONVENTIONAL HEMOSTATIC TECHNIQUE

Traditional haemostatic technique in thyroidectomy may cause some damages to surrounding tissues and it is time consuming. It is believed that these damages and the time can be reduced using ultrasonic dissector devices like Harmonic Scalpel. In this study, we investigate the benefits of harmonic Scalpel haemostasis (HS) versus conventional haemostatic techniques (CT) in total thyroidectomy. Analysis of patient’s data was done for cases with total thyroidectomies performed between 2011and 2015 by the same surgeons using either the conventional technique (Clamp and Tie technique) or the harmonic scalpel for haemostasis. Gender, age, preoperative clinical information, histopathology results,and procedure type were analyzed. and according to the type of haemostatic techniques the collected patient’s data was divided in to two groups; conventional group (CT group) in which the haemostasis was done with Clamp and Tie technique and harmonic scalpel group (HS group) in which the haemostasis was done with Harmonic Scalpel (Sonicbeat Olympus). The outcome and the complications of the both procedures were analyzed statistically and compared. The use of harmonic scalpel in total thyroidectomy significantly decreases mean operative time by (-37.635 min) 60.49±7.78 SD for HS group vs 98.13±14.165 SD for CT group with very significant P-value (0.0000). Statistical significant difference in the mean volume of postoperative drainage in (ml) through redivac drain observed between the two groups; 63.02±19.91SD for HS group and 72.50±22.79 SD for CT group with significant P-value (0.0000). There were no significant difference in the other parameters of the outcome and complications after total thyroidectomy in both groups. It is concluded from this study that main impact of harmonic scalpel in total thyroidectomy is the significant reduction in operative time and its use is safe and not associated with increase in the rate of the complications. Introduction hyroidectomy is one of the frequent operation done over the world. In 952 AD, the first goiter excision had been done by Islam’s medieval surgeon from Andalusia, Abu al-Qasim alzahrawee as mentioned in his book ‘’ Al-Tasrif ’’. A thousand years later, Theodor Kocher ‘‘Father of Thyroid Surgery’’ describes a safe procedure for thyroidectomy and from that time till now this procedure still valid and considered as a gold standard procedure for thyroidectomy. In recent years and despite the revolution in modern surgical procedures toward minimal invasiveness, the original conventional (Theodor Kocher) thyroidectomy remain the only widely accepted procedure and the only accepted changes on this procedure is the method of haemostasis. The methods of haemostasis and ligation of blood vessels during conventional thyroidectomy involves using either frequent clamp and tie with sutures, metal clips or electrocautary, these conventional methods are time consuming and may be associated with complications; frequent clamp and tie may injure the nearby vital T


Introduction
hyroidectomy is one of the frequent operation done over the world.In 952 AD, the first goiter excision had been done by Islam's medieval surgeon from Andalusia, Abu al-Qasim alzahrawee as mentioned in his book '' Al-Tasrif ''.A thousand years later, Theodor Kocher ''Father of Thyroid Surgery'' describes a safe procedure for thyroidectomy and from that time till now this procedure still valid and considered as a gold standard procedure for thyroidectomy 1 .In recent years and despite the revolution in modern surgical procedures toward minimal invasiveness, the original conventional (Theodor Kocher) thyroidectomy remain the only widely accepted procedure and the only accepted changes on this procedure is the method of haemostasis [2][3][4] .The methods of haemostasis and ligation of blood vessels during conventional thyroidectomy involves using either frequent clamp and tie with sutures, metal clips or electrocautary, these conventional methods are time consuming and may be associated with complications; frequent clamp and tie may injure the nearby vital T structures and knot tie may slip leading to life threatening bleeding, metal clips also may dislodge leading to bleeding or erod into adjacent vital structures, sutures and clips are foreign materials may increase the incidence of wound infection, on other hand the use of conventional electrocautary for haemostasis might cause inadvertent injury to vital nearby structures by lateral thermal spread 5 .Recently; ultrasonic energy devices like, harmonic scalpel was developed in early 1990s, this innovative device use ultrasonic energy to create mechanical vibration at a frequency of 55.5 kHz between the two jaws of the device, this friction mechanism produce low heat energy (between 50°C and 100°C) transmitted to the tissue result in denaturation of protein and formation of coagulum with sealing and cutting out of vessel up to 5 mm at the same time with minimal lateral thermal spread 6 .Although the initial use of the harmonic scalpel was in laparoscopic surgery, Published studies suggest that the function of harmonic scalpel in thyroid surgery is safe and effective in decreasing operative time [7][8] 1. Significant statistical difference in the mean volume of postoperative drainage in (ml) through redivac drain also observe between the two groups; 63.02±19.91SDfor HS group and 72.50 ± 22.79 SD for CT group with P-value of (0.0000)* ie (harmonic scalpel reduce volume of drainage by -9.48 ml) as shown in figure 2. There were no significant difference in the mean duration of hospital stay or the mean duration of drain removal.The frequency of complications of the procedures in both groups were shown in table III; two patients in each group developed mild postoperative seroma (1.9% for HS group vs 2.08% for CT group with no significant statistical difference P value=1.000),all cases in both groups were treated conservatively and resolved in few days.Ten patients (9.61 %) for HS group vs 9 patients (9.37 %) for CT group (with no significant statistical difference P value=1.000)developed symptoms of temporary hypocalcaemia and confirm by serum Calcium < 2.1 mmol/ml, were treated with oral calcium and vit.D3 and resolved within few weeks.One patient in each group was developed temporary RLN palsy (0.96% for HS group vs 1.04% for CT group with no significant statistical difference P value =1.000) were confirmed by ENT examination and treated conservatively and recover within few weeks.In both groups; there were no intraoperative or postoperative mortality, no patients need blood transfusion or reoperation for postoperative bleeding, no patients complain of permanent hypocalcaemia or permanent recurrent laryngeal nerve palsy.

Discussion
Our results reported significant reduction in the mean duration of surgery by proximately 37.635 minutes with the use of harmonic scalpel compared to the conventional technique, these results was similar to the international results that show significant reduction in the mean duration of thyroidectomy procedure with the use of harmonic scalpel.Regarding the mean duration of hospital stay and mean duration of drain removal, our study reported no significant difference between the use of harmonic scalpel and the use of the conventional technique, again these results goes with the results of the published studies [8][9][10][11] .With respect to the postoperative drainage volume, published studies reported significant reduction in the mean of the postoperative drainage volume with use of harmonic scalpels 12 , our results also report a small reduction in the mean volume of the postoperative drainage in the HS group in comparison with the CT group but this reduction has no clinical significant impact in the outcome in term of duration of hospital stay and duration of drain removal.The most important complications of total thyroidectomy are the recurrent nerve palsy, hypocalcemia and postoperative haematoma with variable rate depend mainly on the surgeon experience [13][14][15] .In our study, we found no permanent recurrent laryngeal nerve palsy, however, there were few cases in both groups develop transient recurrent nerve palsy with no significant statistical difference and both of these results are similar to published results 16,17 .Permanent hypocalcemia was not reported in our study, and the reported difference rate of the transient hypocalcemia between the two groups was not statisticaly significant and this results was similar to the published results [18][19][20][21][22] .
According to the published literatures, the rate of postoperative haematoma and seroma was (0% and 2.5%) [23][24][25] , our results also reported same findings with no significant statistical difference between two groups; 2 patients (1.9% for HS group) and 2 patients (2.08% for CT group), the haematoma and seroma were absorbed spontaneously within few days without reoperation.Harmonic scalpel has been approved by published studies to have better haemostatic effect in comparison to coventional technique 26,27 , our results does not report any cases of intraoperative or postoperative bleeding who need blood transfusion or reoperation in both groups.
No mortality was reported in our study while published data reported negligible mortality due to thyroidectomy 28 .

Conclusion
The main significant impact of this ultrasonic energy device in total thyroidectomy is the significant reduction in operative time in comparison to conventional haemostatic technique and it's use is safe and not associated with increase in rate of complications.

24 .Figure 1 :
Figure 1: Mean duration of surgery in both groups:

Figure 1 :
Figure1: The mean operative time (min) for HS group was 60.49±7.78SD while for CT group was 98.13±14.165SD with significant statistical difference P-value (0.0000)* ie (the operative time for HS was shorter than that for CT by 37.635 minutes