Endoscopic posterior decompression of lumbar canal stenosis

Abstract

Lumbar canal stenosis (LCS) is quite common. Surgery is indicated when patient fails to improve after conservative treatment. Endoscopic technique can be used in LCS and lateral recess stenosis. It can be performed in degenerative canal stenosis or with disc bulges. Bilateral severe bony canal stenosis and unstable spine are the contraindications. This procedure should be avoided in patients with a history of trauma. Detailed history and thorough physical examination should be performed to find out exact level of pathology responsible for symptoms. Patient’s symptoms must correlate with radiological findings. Magnetic resonance imaging is the investigation of choice because of its superior visualization of soft-tissue. Computed tomography scan does give a more accurate and detailed picture of the bony anatomy. Although the operative time and the complication rate could be more in the initial learning curve, the results of endoscopic decompression are comparable with conventional open procedures with the additional benefit of decreased complications and lower morbidity, when sufficient experience is gained. Complications in endoscopic surgery for LCS could be dural tears, hematomas and root and facet injury. This procedure is also associated with limitations such as steep learning curve and the contra lateral decompression may not be as good as ipsilateral side. Some of the limitations of this technique can be overcome by attending live operative workshop, practice on models and hands on cadaveric dissection. Conversion to an open procedure may be required when there is disorientation, management of dural tear and for control of bleeding.

Microendoscopic bilateral Decompression via Unilateral Approach in Single and Multiple Level Lumbar Canal Stenosis: A Series of 583 Cases

“…33 Various imaging modalities are utilized to diagnose and characterize LCS including static and dynamic radiography, CT, CT myelography, and the gold standard MRI. 9,57 In the present study, we adopted imaging with CT to confirm central LCS diagnosis via measurement of cross-sectional diameter of the dural sac at the disc level.…”

Practical aspects in neuroendoscopic techniques and complication avoidance: a systematic review.

“…It is better to keep the tubular retractor or endoscopic sheath as vertical as possible, as angulation of this sheath invites surrounding structures to enter inside the tube, which may stain the lens tip or may interfere with proper visualization (30,36). It is therefore advisable to use two incisions to address two levels of spinal pathology rather than too much angulation using a single incision.…”

“…Dural tear is not uncommon when there is severe canal stenosis in spine surgery. This is more common when dealing with opposite side compression in spinal surgery (32,36). There is also a predisposition when the dura is adherent to the cranial bone.…”

Endoscopic decompression of cervical spondylotic myelopathy using posterior approach

“…Dural tear may occur when dura matter is caught in the Kerrison punch. Keeping ligamentum flavum until all the bony work is over, [9] using eggshell drilling of bone and removal of thinned out lamina by micro instruments can prevent dural tear. Dural tear due to Kerrison punch can be prevented by partially retracting the Kerrison punch after disconnecting piece of bone to be removed from rest of the lamina and then holding the proximal part of the tissue before it is removed.…”

“…Dural tear due to Kerrison punch can be prevented by partially retracting the Kerrison punch after disconnecting piece of bone to be removed from rest of the lamina and then holding the proximal part of the tissue before it is removed. [9] Diamond burr or ultrasonic bone dissector (remove bone without injuring soft tissue) can be used to decompress under surface of opposite side lamina without injuring dura matter. Small dural tear may need simple placement of Abgel or fat over defect while larger defect may require fascia lata or dural substitute along with tissue glue.…”