Ultrasound Guidance for Full Endoscopic Spinal Surgery: A Technical Note

The use of intraoperative ultrasound (IOU) has proven to be useful in spinal surgery. In this study, we present the techniques of applying IOU in cervical, thoracic, and lumbar full-endoscopic spine surgery (FESS). For applying IOU in cervical FESS, first, we localize the surgical level by identifying the unique shape of C6 and C7 under ultrasound and then identify the cervical level subsequently. For the anterior approach, the endoscope passes through the cervical fascia between the carotid sheath and trachea/esophagus, which can be identified under ultrasound, and for the posterior approach, the endoscope docks on the facet joint under ultrasound. For applying IOU in thoracic FESS, we localize the surgical level by counting the ribs. The endoscope is advanced to the neural foramen under ultrasound without entering the pleural cavity. For applying IOU in lumbar FESS, we identify the surgical level by counting the interlaminar window from the sacrum. The endoscopic sheath is advanced to the neural foramen under ultrasound without entering the peritoneal cavity. The use of IOU in FESS has the potential to reduce radiation exposure, reach a higher successful puncture rate, and decrease the operation time. Furthermore, IOU prevents radiolucent organs from damage during FESS. We present the techniques of applying IOU in cervical, thoracic, and lumbar endoscopic spine surgery and hope that this will be helpful for physicians to master the IOU techniques.