baholzer - Endoscopic Spine

22 © baholzer Endoskopie-Systeme GmbH & Co.KG SPINE Introduction to lumbar transforaminal endoscopic disc surgery 2. INTRAOPERATIVE SETUP AND PATIENT POSITIONING 2.1 POSITIONING a.) Prone position with lordosis reduction is recommended to increase the neuroforaminal volume during surgery. b.) Alternatively, the patient can be placed in the lateral decubitus position (side of the herniation facing up). 2.2 ENTRY MARK At the surgical level, the median and lateral interpedicular line should be drawn on the skin (IMG 4, 5). The fa- cet joint can be marked out in between these two lines under fluoroscopic control. The surgical level should be marked on both AP and lateral X-Ray views (IMG 6, 7). The iliac crest especially for accessing the level L5/ S1 should be marked out as well. Typically, the intersection of planning lines on the AP and lateral views often coincides with the optimum entry point. Adjustments for proximal or caudally migrated disc fragments may be taken into consideration when choosing the final entry point. 3. PLACEMENT OF GUIDE WIRE AND WORKING SHEATH Once the desired entry point has been chosen and a small stab skin incision has been made, a long spinal needle is placed in the distal portion of the neurofora- men under fluoroscopic control as near to the disc herniation or stenotic lesion as possible. Alternatively, the guide-wire can be placed intraosseously at the transi- tion of pedicle/superior articular process (SAP). This can be helpful in performing a foraminoplasty to gain access to a far-migrated disc herniation. Access to the foramen will be achieved by sequential dilation of the lateral spinal musculature over the guide wire (IMG 8). IMG 4 IMG 8 Seq. dilation IMG 5 IMG 6 IMG 7