Tricks & Pitfalls in Endoscopic Spine Surgery
Endoscope has made strides in all fields of medicine. There is no doubt
that future of surgery lies in development of minimally invasive techniques and
that spinal surgery does not escape this rule.
The philosophy/tricks of minimalism in spine surgery are based on three basic principles. One is use of tubular retractor, second is use of endoscope for better illumination/visualization with magnification at depth, and third is angulation with endoscope to visualize the hidden areas beyond the tubular retractor.
The tubular retractor helps in less traumatic retraction of the muscles, at the same time it can be moved in all directions. Recent trends and instrument modifications have resulted in use of microscope with the same tubular retractor. This accurately demonstrates that the most important factor in this surgery is the new retraction technique which is less traumatic with small size incision. Minimal access surgical techniques can be performed well with either method of visualization, ie. Microscope and endoscopic visualization. The endoscopic technique offers a unique advantage in the lateral decompression of lumbar stenosis, because the endoscope can be moved in all directions. Contralateral visualization of lateral recess and foremen are vastly superior to that which can be achieved with the microscope.During the contralateral decompression of the lateral recess cutting edge of the Kerrison punch is always away from the root and dura. Therefore contralateral decompression of lateral recess and foramen can be performed more safely and more thoroughly with endoscope than with microscope.
Pitfalls of wrong level localization of disc space can be overcome by use of a special device -localizing pin- which helps in exactly localizing the disc space. This device has no parallax in localizing in both AP & lateral plane. This helps in minimizing the incision. Mobility of the endospine and natural caudal angulation of L5/ S1 disc space helps us in operating both L4/5 & L5/S1 levels through the same incision of 2.5 CMs.
Pitfalls of dural & nerve root injury is overcome by use of cotton wool at each and every step to protect these structures in the initial steep learning stage.
For haemostasis of epidural bleeding endoscopic bipolor is of great help as it is used in routine surgery.
Pitfalls of endoscopic surgery in a patient who has underwent open laminectomy is a challenge for an endoscopic surgeon. Here one has to identify bone in the lateral recess or if it is not possible then to identify the isthumus and dissect the foramen from lateral to medial medial to the exiting root and approach the disc.
The distal end of endoscope emitts high energy radiation light at temperature exceeding upto 41 degrees centigrades within 8mm in front of the scope. Therefore donot leave the tip of endoscope in direct contact with the patient's tissue.
Pitfalls during endoscopic spine surgery can be avoided by proper pt. selection, through preoperative planning of approach. Surgeon should master the technique before using it as treatment method so as to minimize the technique related complications.
Technique should have nice equilibrium between adequate neural decompression with preservation of stability. Error on either side will add complications.
Results and complications of more than 400 cases endoscopically treated in last 6 yrs will be discussed with visuals to explain use of endoscopic technique.