H Leu. Endoscopic lumbar surgery: a personal experience since 1986. The Internet Journal of Minimally Invasive Spinal Technology. 2008 Volume 3 Number 4.
Based on Japanese uniportal percutaneous technique of closed percutaneous nucleotomy introduced in 1979, in 1982 intradiscal biportal endoscopy was introduced in Zurich for visually controlled intervertebral tissue elaboration. Beside decompressive indications, in 1987/88, in combination with percutaneous external pedicular fixation, endoscopy controlled interbody fusion was introduced.After a decade in clinical experience with this biportal application, the idea arose to combine simultaneous endoscopic control with direct extradiscal tissue elaboration across a uniportal approach in the later eighties.Experiments with modified urologic workings-scopes designed for cystoscopic applications demonstrated in 1990, that endoscopic applications are possible also in non-preformed anatomical spaces when some hyperpressive irrigation was used for local traumatic tissue spacing. So we introduced endoscopic coaxial foraminoscopy clinically for the first time in February 1991 for the treatment of a foraminal sequestrated herniation. A first publication on the early series was published in 1996. Since then the technology with improved endoscopic tools and irrigation systems as well as high-frequency cogulation under irrigation became almost standardized for this specific range of indication. The posterolateral approach from 9-12 cm from the midline follows the same criteria as for intradiscal applications, but the working cannula is directed to the foraminal sequestrum, which is extracted under endoscopic control then with a special working scope. After a steep learning curve today the optimal indications and contraindications are clearly defined. Our first clinical series of 200 standardized cases brought successful primary results in 164 cases, including the learning curve. Here the results trend to "black or white": or the sequester is removed or not. Relatively freshly sequestrated fragments without local scar-adhesions are easier to remove. Anatomical limits can occur in L5/S1 when high iliac crests can impair flat approach to medioforaminally located sequestra. For pre-op evaluation a 3d-CT offering clear bony analysis of accessible trajectories can trace the access precisely. Detailed knowledge of foraminal anatomy is mandatory. Hospital stay could be reduced to 2 to 3 days, out patient care is possible nowadays as well. Other pioneering authors as Ruetten in Germany broungt up the interlaminar endoscopic lumbar decompression, what definitely extende the range of this minimal endoscopic approach also to more medilateral forms of lumbar disc herniation. So the available complementary endoscopic techniques today challenge in well trained hands more and more the conventional golden standards as microdiscectomy.