The preliminary application of free-run electromyography in percutaneous endoscopic interlaminar discectomy

English Keywords:Free-run electromyography  Percutaneous endoscopic interlaminar discectomy(PEID)  General anesthesia  Intraoperative monitoring

English Abstract:

  【Abstract】 Objectives: To investigate the application feasibility and outcomes of free-run electromyography(Free-EMG) in percutaneous endoscopic interlaminar discectomy(PEID) under general anesthesia. Methods: From March 2016 to June 2017, total 86 patients with lumbar disc herniation received PEID under general anesthesia were retrospectively analyzed, including 62 males and 24 females with an average of 41.2±8.1 years old(23 to 64 years). Free-EMG was used for continuous nerve root function monitoring in all cases, and the waveform, peak and number of motor units were observed. Any type of myoelectric response indicated that the nerve root was provoked, and the continuous explosive electromyographic response indicated that the nerve root was subjected to continuous tension or compression. If there was a significant abnormality of myoelectric response at the end of operation, it was predicted to be nerve root injury, which would be compared with the postoperative symptoms. Results: Free-EMG monitoring showed an electromyographic response at intraoperative touch, push and pull on the nerve root, with a recordpositive rate of 100%. The postoperative symptoms of 79 patients were significantly released, 6 cases had symptoms of lower limb scorching pain, and the lower limb muscle strength was decreased and numbness was increased in 1 case. There was an obvious intraoperative myoelectric response in 1 case and it was normal at the end of operation. The false negative rate was 1.16%. In 2 cases with postoperative symptoms released, there were obvious intraoperative myoelectric responses at the end of operation. The false positive rate was 2.32%. Conclusions: The Free-EMG monitoring can accurately indicate the nerve root disturbance in the operation of PEID under general anesthesia, thus reducing the probability of nerve injury.