| Purpose:Through the analysis of the monitoring data of the recurrent laryngeal nerve,explore the parameters of the EMG signal that can describe the nerve function in addition to the amplitude and the incubation.Explore the prognosis of the nerve function recovery by different injury factors.Find the coping methods after the intraoperative nerve injury.Distinguish the pros and cons of different predicting abnormal vocal cord movement methods.Calculate the relative and accurate predictive value of EMG signal to predict abnormal vocal cord movement.Method:First,an animal model of porcine recurrent laryngeal nerve injury was established.By simulating the nerve injury,the amplitude recovery within 10 minutes after the nerve injury was observed,and the EMG signal parameters that could describe the nerve function were found.After that,clinical trials were conducted.A total of 931 patients with complete EMG signals and meeting the criteria for inclusion and exclusion were included as the research objects.Perform fiber laryngoscopy and preoperative medical history evaluation for all preoperative patients.During the operation,strictly implement the six-step method of nerve monitoring for operation and data recording.If the EMG signal of the recurrent laryngeal nerve in the patient drops below 50% of the initial value of the recurrent laryngeal nerve in the patient,it is judged that the recurrent laryngeal nerve injury may occur.When the injury occurred,if the amplitude decreased to 10-50% of the initial value,it would be included in the incomplete LOS group.And if the amplitude decrease to 0-10% of the initial value or the amplitude value is less than 100μV,it would be included in the complete LOS group.For patients with possible recurrent laryngeal nerve injury,the operation should be stopped immediately when the signal drops to 50%,and the injury factor should be removed and then wait for 10 minutes.The EMG signal of the recurrent laryngeal nerve under the injury point is detected and recorded every 2minutes.The EMG signals involved in the experiment were recorded with the handwritten nerve monitoring scale and the screenshot function of the nerve monitoring equipment.All patients need to undergo laryngoscopy and record the results after surgery.Photoshop software was used to process the EMG signal screenshots,and the area under the curve,duration and other information were obtained by surveying and mapping pixels.Statistical analysis was performed using SPSS(IBM,Armonk,New York,USA).Use nonparametric tests to compare continuous variables between groups.Mann-Whitney U test and Chi-square test were used to compare differences between patients.The receiver operating curve(ROC)is used to study the critical value of the amplitude change of nerve monitoring to predict the functional outcome after thyroidectomy.Result:1.Porcine animal model recurrent laryngeal nerve injury experiment: For the incomplete LOS group,the amplitude and area under the curve increased with the waiting time,and the parameter values gradually increased.Suggests that for the incomplete LOS group,after the nerve injury factors are eliminated and stop the operation,nerve function may have recovery potential.At the same time,the recovery of the area under the curve is similar to the amplitude,suggesting its feasibility as an indicator of neurological function.However,the incubation period and duration of the incomplete LOS group did not recover significantly with the recovery of neurological function,suggesting that it may have poor ability as an indicator of neurological function.For the complete LOS group,the EMG signal is difficult to recover,suggesting that once LOS occurs,it is difficult to observe the obvious recovery of EMG signal during the operation.2.The effect of different injury mechanisms on postoperative vocal cord movement: For the incomplete LOS group,more than half of the traction injuries can be obviously observed in the amplitude recovery during the operation,suggesting a better neurological prognosis.For the complete LOS group,only 1 case of traction injury was observed to restore the amplitude of the EMG signal to more than 50% of the initial value.The three injury factors that often lead to incomplete LOS(traction,compression,unexplained cause)are generally better in vocal cord movement,while the injury factors that lead to complete LOS group(tumor invasion,mechanical device injury,thermal injury)are all suggested poor postoperative vocal cord movement.3.The effect of waiting for 10 minutes during the operation on the EMG signal recovery of the recurrent laryngeal nerve: For the EMG signal of the incomplete LOS group and the complete LOS group,the paired rank sum test of the relevant samples was carried out respectively,indicating that in the 10 min recovery process,there are statistically significant differences in amplitude and area under the curve between groups(p<0.05).But there is no statistically significant difference between the duration groups(p>0.05).Suggest that waiting for 10 minutes during the operation is helpful for the recovery of neurological function.4.Experiment on the predictive effect of decrease of EMG signal on postoperative abnormal vocal cord movement: For all patients,the cut-off value was calculated by Youden index.It can be seen that when the percentage of amplitude decrease exceeds 44.64% as the cut-off value,the Youden index for diagnosing abnormal postoperative vocal cord movement is the largest,and the sensitivity and specificity are 65.5% and 93.7%,respectively.Youden index is 0.592.A 44.64%decrease in EMG signal can be used as a relative predictive value for predicting abnormal vocal cord movement after surgery.For patients with an amplitude decrease of more than 50%,when the 10 min amplitude decrease percentage exceeds 73.87%as the cutoff value,the Youden index for diagnosing abnormal postoperative vocal cord movement is the largest,and its sensitivity and specificity are 88.2% and 60.0%respectively,and the Youden index is 0.482.The decrease of EMG signal amplitude by more than 73.87% can be used as an accurate predictive value for predicting abnormal vocal cord movement after surgery.Conclusion:1.After the recurrent laryngeal nerve is injured,it is an effective means of coping with the injury of the recurrent laryngeal nerve to eliminate the injury factors and wait for 10 minutes.2.A 50% reduction in the amplitude of the EMG signal of the recurrent laryngeal nerve can be used as a warning line for damage to the recurrent laryngeal nerve.3.After 10 minutes of recurrent laryngeal nerve injury,the decrease in amplitude relative to the initial value is the most suitable predictive method for intraoperative judgment of postoperative vocal cord movement.The area under the curve is similar to the amplitude in predicting the integrity of neural function,and is also an effective parameter of EMG signal... |
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