The Learning Process of Endoscopic Spinal Surgery for Degenerative Cervical and Lumbar Disorders Using the EasyGO! System

BACKGROUND: Among spinal surgeons, the safety of endoscopic spinal techniques has been criticized as the result of a prolonged learning curve and divergent surgical technique from traditional microsurgery. In this manuscript, the authors assessed the learning curve of 4 experienced microsurgical neurosurgeons in endoscopic spinal surgery. METHODS: Retrospectively, the surgical reports, the endoscopic video recording, and the files of all patients who underwent an endoscopic procedure for the treatment of cervical and lumbar disc herniation from January 2011 to December 2017 were reviewed. The learning process was assessed via several parameters: surgical time, intraoperative complications, dural tear, nerve root injury, conversion to microsurgery, new postoperative neurologic deficits, repeated procedure, and early recurrent disc herniation. RESULTS: The learning process of for 4 surgeons was assessed on the basis of 308 procedures. The mean surgical time for the initial procedure ranges from 58 to 97 minutes and improved to 51-85 minutes for the last procedures. A shorter surgical time had no influence on the rate of intraoperative complication and repeated procedure. Increased working space had a significant influence on the surgical time. The number of procedure to reach the asymptote varied from 10 to 20 depending on the endoscopic system and the surgeon. CONCLUSIONS: The learning process in endoscopic tubular-assisted spinal surgery is variable, and the asymptote might be reached after 10-20 procedures. The amount of working space and instrument angulation affects the surgical time. The decrease of surgical time had no significant influence on the rate of intraoperative complication and repeated procedures.