Application of hydrodissection to expose recurrent laryngeal nerve during thyroid surgery

Objective To investigate the application value of hydrodissection to expose the recurrent laryngeal nerve in thyroid surgery. Methods Seventy patients undergoing thyroid surgery were randomly divided into the hydrodissection group （n = 35） and control group （n = 35）. In the hydrodissection group， the recurrent laryngeal nerve was exposed by local injection of normal saline. And in the control group， the recurrent laryngeal nerve was exposed by blunt dissection. The operation time， blood loss， length of hospital stay， exposure time of recurrent laryngeal nerve， incidence rates of recurrent laryngeal nerve injury and hypocalcemia were compared between two groups. Results 46 recurrent laryngeal nerves were exposed in the hydrodissection group and 54 in the control group. Surgeons found that hydrodissection could more explicitly display the course of recurrent laryngeal nerve. One case of temporary recurrent laryngeal nerve injury occurred in the hydrodissection group and five cases in the control group， and the difference was not statistically significant （P > 0.05）. No permanent recurrent laryngeal nerve injury was observed in both groups. The exposure time of recurrent laryngeal nerve， operation time， blood loss， incidence rate of hypocalcemia and length of hospital stay did not significantly differ between two groups， and the differences were not statistically significant （all P > 0.05）. Conclusion It is convenient and simple to expose the recurrent laryngeal nerve through hydrodissection. As a safe and reliable Method to expose the recurrent laryngeal nerve， hydrodissection can accurately identify the course of the recurrent laryngeal nerve and avoid mechanical injury induced by excessive dissection of the nerve.