Minimally invasive surgical approach to the Thessys foraminoscopic spine In order to precisely determine the location and nature of the herniated or prolapsed nucleus pulposus, as well as the condition of the foraminal osteophytes, a thorough clinical and neuro-orthopedic examination is performed prior to surgery. Imaging, especially CT and MRI, are important to precisely determine the size, location, and nature of the nucleus pulposus. The final diagnosis is confirmed by discography. Appropriate patient positioning and precise design of the disc approach from the skin to the herniated disc are essential to obtain a good surgical outcome. The lateral or prone position can be chosen depending on the location and nature of the herniated or prolapsed nucleus pulposus. THESSYS combines approaches and techniques to do all disc nucleus pulposus removal, fibrous annuloplasty, and resection of osteophytes from the cervical spine to lumbar 5 sacral 1. Any isolated disc fragment or herniation can be removed immediately with this system. The special way to reach the herniated disc using this approach is through the foraminal safety triangle, which is usually very narrow in the case of disc prolapse. The affected nerve root emanates from the cephalad side and is usually surrounded by fibrous tissue and/or a bony conus. In order not to irritate any nerve close to the foramen and to ensure safe access to the spinal canal, the caudal part of the foramen (safety zone) has a specially designed drill 1 mm by 1 mm enlargement. Using a stepped guide wire and a 3-segment puncture cannula under radiographic control, the intervertebral foramen is inserted from the THESSYS manual instrumentation disc containing a variety of guide rods, catheters, working canal lumen and the previously mentioned coronal do-drillers. The intervertebral foramen is gradually widened by drilling through the bony material. This process allows for safe access to the spinal cavity. Using a spinal needle, the precise location of the annulus fibrosus tear, disc material prolapse and/or isolation can be confirmed. Through this access and a specially developed spinal foraminoscope, specially developed forceps, graspers and perforators are used to remove the prolapsed material causing severe radiological symptoms. THESSYS can be used for any herniated disc in a minimally invasive procedure. All isolated disc material and prolapses of the lumbar spine (including the 5th lumbar and 1st sacral intervertebral spaces) can be removed using the entire system under local anesthesia through the lateral intervertebral foramen. The use of the whole system is indicated for any nerve root symptoms or chronic pain caused by herniated discs or larger herniations for which conservative treatment does not yield adequate improvement. Cauda equina syndrome represents an indication for immediate surgery. For any surgery of herniated discs, the THESSYS procedure also requires thorough preoperative magnetic resonance, computed tomography and routine radiographic imaging. Published international literature has reported success rates of more than 90% at 1 and 2 years postoperative follow-up with the THESSYS approach, with early recurrence rates of less than 5%. In patients with recurrence, the success rate exceeds 84%. In cases of recurrent disc herniation, the success rate exceeded 85%.