Background: The ultrasonic dissector (UD) is an instrument that uses vibration to coagulate and cut tissue simultaneously. The main advantage of a UD instrument compared with a standard electrosurgical device is represented by minimal lateral thermic tissue damage allowing a wide application in thyroid surgery. A new UD (NUD), with a tip smaller than 5 mm, might enable a more precise dissection near vital structures such as parathyroid glands and recurrent laryngeal nerve. To evaluate the NUD during thyroid surgery, a prospective randomized study was performed using the new device versus traditional procedures.
Subjects and methods: Two hundred sixty-one patients underwent various thyroid surgical procedures; they were randomly assigned (130 in the NUD group and 131 in the conventional hemostasis [CH] group). The two surgical groups were compared in age, sex, diagnosis, thyroid size, operative time, drainage volume during the first 24-48 hours after surgery, and complications (hypoparathyroidism, damage of the recurrent laryngeal nerve, and postoperative pain).
Results: The two groups were similar regarding age, sex, numbers of lobectomies and total thyroidectomies, and numbers of focal and diffuse pathologies. Mean ± standard deviation operative time was shorter in the NUD group compared with the CH group for both lobectomy (70 ± 21 minutes versus 99 ± 27 minutes; P<.01) and total thyroidectomy (91 ± 37 minutes versus 121 ± 42 minutes; P=.01) procedures. No difference was found regarding the amount of drainage volume for different procedures (P=not significant). Postoperative transient (P=.01) and definitive (P=.01) hypoparathyroidism occurred more frequently in the CH group than in the NUD group. There was a significant difference regarding the transient damage of the recurrent laryngeal nerve: 7 patients (5.3%) in the NUD group and 13 patients (9.8%) in the CH group (P=.01). There was no difference regarding definitive damage to the recurrent laryngeal nerve and pain.
Conclusion: This NUD may reduce the rate of complications (transient and definitive hypocalcemia, transient damage of the recurrent laryngeal nerve) and operative time.