RIWOspine 360° full-endoscopic Spine Surgery
Endoscopic imaging has also been playing an important role in spine surgery for many years, because high-resolution intraoperative imaging facilitates minimalized access ports to the operating site. This therefore provides a tool designed to implement concepts for minimally invasive surgery.
Alongside the ventral endoscopic approaches to the spinal column, which are mainly used thorascopically for fractures and tumors, endoscopy is also being increasingly used for dorsal and lateral approaches in degenerative diseases.
Moreover, since the endoscope is used very differently in these techniques, further differentiation was required in order to compare the various techniques effectively. Techniques that place the endoscope for visualization in the operation tube are designated as endoscopically assisted procedures (e.g. also MED for micro-endoscopic discectomy).
Furthermore, full-endoscopic procedures have been developed and standardized in particular over the past 20 years by Richard Wolf GmbH.
Indications for the use of the endoscopic spine surgery
Disk herniations are the main indication for the use of the Endoscopic spine surgery
The concept was developed for all disk herniations that cannot be treated using conservative therapies. The following objectives should always be a top priority:
- Direct decompression of neural structures: “target approached” access to reach and remove the disk herniation directly.
- Least invasive access trauma: choosing the approach with minimally traumatization of surrounding soft tissue and bone structures which don´t belong to the pathology.
- Reducing the risk of recurrences: partial and selective diskectomy to reduce the risk of recurrences.
Standardized surgical approaches have been developed in order to meet the requirement for minimal invasiveness.
Transforaminal approach is used for pathologies starting at L4/5 and higher segments.
In order to meet the concept’s demand for direct decompression and least invasive access trauma, different access directions are selected for the transforaminal approach:
Lateral transforaminal approach
- Access direction approx. 20° to horizontal
- For intraspinal (mediolateral) and intraforaminal (lateral) localized pathologies
- Access to the ventral epidural space and the dorsal intervertebral disk
Posterolateral transforaminal approach
- Access direction approx. 45° to horizontal
- For intradiscally localized pathologies
- Access to the central disk
In narrow intervertebral foramina, parts of the ascending facet and pedicle can be removed with manual and motorized burrs to achieve free access.
Extraforaminal approach is selected for extraforaminal disc herniations and foraminal stenosis for all segments of the lumbar and thoracic spine.
Prefered lateral to posterolateral access direction with 20° to 30° to horizontal. In order to prevent injuries to the exciting nerve root, the puncture cannula is anchored in the caudal pedicle. From there, the VERTEBRIS diskoscope with working sleeve and instruments is moved cranially under full-endoscopic view to identify and remove the herniated disc.
Preferred indications for interlaminar access are intraspinal localized pathologies in L5/S1, where the use of burrs for lateral extension of the interlaminar window is not required.
However, this is necessary if the interlaminar full endoscopic approach is used in higher segments of the spine or if spinal stenoses have to be surgically expanded for decompression. The interlaminar access direction is posterior.
Spinal canal stenosis
Neural structures of the spine can become compressed by the bony and ligamentous tissues of the spinal canal. Categorization by means of localization is effective in lateral (foramen, lateral recess) and central stenosis of the spine.
Stenosis of the foramen leads to compression of the exiting nerve root and manifests as primarily radicular symptoms. The cause of foraminal stenosis is degenerative bony structures at the facet joints and pedicles.
- The preferred method to address foraminal stenosis is to perform resection of the foraminal bone using a full-endoscopic transforaminal or extraforaminal approach. The Tip-Control Articulating Burr is used through the VERTEBRIS lumbar endoscopic system to remove the impinging bone under direct endoscopic visualization. Nearby neural structures are visually identified and protected with the working sleeve.
- Alternatively, it is possible to use trephines or hand burrs percutaneously to widen the foramen. The instruments are positioned and used under fluoroscopic visualization.
Lateral recess stenosis
Lateral recess stenosis causes compression of the traversing nerve root and lateral portions of the spinal cord. This is a result of constriction of the bony structures in the lateral recess of the spinal canal.
Stenosis in the lateral recess is best addressed by careful resection of bone through a full-endoscopic interlaminar approach. A variety of burrs are available to remove the impinging bone through the VERTEBRIS lumbar endoscopic system under direct endoscopic visualization.
The approach is more lateral than the standard interlaminar approach. First, with the ligamentum flavum still intact, the descending articular process is resected with the burr from the caudal tip up to the level of the tip of the ascending articular process. Next the ligamentum flavum is opened using suitable punches and the neural structures are localized before the lateral decompression of the facet is finished using diamond burrs or laterally hooded carbide burrs.
Central stenosis may cause compression of lateral and central parts of the spinal cord as well as of traversing nerve roots depending on their location and characteristics. Correspondingly the patient’s symptoms may be central or radicular in nature.
Central stenosis can be addressed by resection of the impinging bone and hypertrophied ligamentum flavum using an ipsilateral full-endoscopic interlaminar approach with additional extension of the procedure to the contralateral side.
The VERTEBRIS stenosis system was developed especially to perform bilateral bony decompression of the lumbar spine with the same effectiveness as conventional MIS and open procedures.
The procedure is started in the same manner as the recess stenosis case mentioned above. Additionally, the bone resection is extended towards the cranial and caudal lamina. Afterwards, the resection of the ligamentum flavum is carried towards the contralateral side with Kerrison punches. The decompression of the contralateral recess is performed with an “undercutting technique“ using special burrs (i.e., diamond and eccentric laterally protected burrs) to protect the neural structures.
Compared to conventional surgery, the full-endoscopic decompression can be done more selectively by sparing surrounding bone and tissue structures that do not affect the compression.
Facet and sacroiliac joint syndrome
The facet-joint syndrome is one of the degenerative diseases of the spinal column. Generally, a loss
of fluid in the nucleus pulposus leads to decreased resilience and elasticity in the intervertebral disks. This wear of the discs can lead to segmental instability and result in additional stress on the facet joints.
The increased stresses exerted on the synovial joint membrane frequently generate mechanical inflammatory reactions. Ultimately, this leads to so-called spondylarthrosis, i.e. changes to the synovial joint membrane and the joint capsule, is similar to arthrosis of other joints.
Spondylarthrosis can either present as an independent medical condition, which is referred to as a facet joint syndrome, or as a cause of other medical conditions (e.g. narrowing of the spinal canal or spinal canal stenosis).
The small vertebral joints (facet joints) are surrounded by a dense network of nerve fibers. These become irritated by the inflammatory processes which occur during the course of arthrosis. However, direct mechanical irritation is also possible as a result of instability. The main symptoms are therefore back pain or neck pain without significant radiation and without neurological deficits. The pain is conducted along the medial branches of the dorsal ramus of the spinal nerve.
Pain is normally a warning signal. However, if the pain becomes chronic, it loses this warning function. Interrupting the further transmission of pain therefore makes sense. The objective of interventional pain therapy is therefore to shut down this nerve and the branches of the nerve in order to prevent the perception of pain. Facet infiltration or facet denervation are the treatment measures available as treatment options.
In addition to the small vertebral joints, the sacroiliac joint (SI-J) is also a generator of back pain. The mechanisms are similar here. Sacroiliac joint syndrome frequently occurs after stabilization of the spinal column because this results in an additional burden on the sacroiliac joint. This in turn leads to mechanical and inflammatory irritations of the nerves at this joint. The pain here is also conducted along the dorsal ramus. This can then be thermally excluded at the sacral exit.
Diskogenic pain syndrome
Diskogenic pain syndrome is one of the degenerative diseases of the spine. The cause of diskogenic pain syndrome is degenerative wear of the vertebral disk, starting with a loss of fluid in the inner core of the vertebral disk (nucleus polposus). Since the vertebral disks then lose resilience and elasticity, this can lead to segmental instability. Sensitization of the region can result in a reduction of the stimulus threshold and lead to chronic diskogenic pain.
Furthermore, protrusions of the vertebral disk can press on the spinal and extraspinal nerve structures and generate radicular pain as a result.
Interventional Percutaneous 4 MHz Radiofrequency Nucloplasty
The PERCULINE nucleo system has been developed for nucleoplasty of the vertebral disk with 4 MHz technology.
The Radioblator RF4 radiofrequency generator with a working frequency of 4 MHz is the centerpiece of this effective tissue-preserving coagulation System. In combination with the actively articulating TipControl RF Electrode the controlled positioning of the radiofrequency application in the tissue is guaranteed.
Focused energy input with less heat penetration to the surrounding tissue, tissue cooling by continuous flow function and reusable access instruments makes the PERCULINE nucleo system efficient