Experimental Investigation And Clinic Study Of The Intraoperative Monitoring And Locating On The Recurrent Laryngeal Nerve

OBJECTIVE: 1 to identify the recurrent laryngeal nerve and to access its integrity of the nerve with NIM-Response and NIM-Pulse system intraoperationly. 2. setup the storage of normal data or determination of normal limits. 3 to explore the threshold and the best stiraulate-response threshold of the EMG intraoperationly . 4 to imitate the operative damage and to access the electrophysiologic function of the recurrent laryngeal nerve. 5. clinic observation intraoperationly for the patients.Material and method:1.Animal experiment:Instrument: NIM-Response and NIM-Pulse system made of Medtronic-MOMED, USA; stimulus mount 0.2mA, 0.4mA 3.0mA separately; Velocity Rate, 4c/s; duration, 100S; event threshold, 100 ~ 1000V; filter, 3.10mS; time scale, 50mS, vertical scale, 500VMethod:Normal data group: 40 dogs were measured under general anaesthesia. The stimulator electrode was put on the surface of the recurrent laryngeal nerve and the record electrode were located at the thyroarytenoid muscle,lateral cricoarytenoid muscle and posteriorcricoarytenoid muscle. Comparing the onset latency, peak latency, amplify, duration, probing into the threshold and the best threshold, and setup the storage of normal data or determination of normal limits.20 dogs were classified randomly into four types, ligature, jaw, 3mA electron current stimulator group (max output current), and end-to-end anastomosis of the recurrent laryngeal nerve. 2 dogs as control group. 3mA electron current stimulator group have no change after the operation. Other groups lost the transmit faction of the current. The threshold was 0.2mA and the best threshold was 0.4mA.2. Clinic study:40 patients of neck operation were inspected with NIM-Response and NIM-Pulse system made of Medtronic-MOMED, USA; stimulus mount 0.2mA, 0.4mA could conduct the typical EMG of recurrent laryngeal nerve. It is helpful to locate the RLN and the lesion position in the neck operation.Conclusion:1.The main advantage to intraoperative RLN monitoring is in help with the initial identification of the RLN and assessment of the integrity of the nerve at the end of the case. 2.The threshold was 0.2mA, and the best threshold was 0.4mA.3. 3mA stimulator is still safe and stabilization. There are no influence on the NIM.