New Ultrasonic Dissector Versus Conventional Hemostasis in Thyroid Surgery: A Randomized Prospective Study

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.