Posterolateral lumbar discectomy is a visualized method for minimal access to the disc and epidural space that avoids surgical morbidity to the dorsal muscle column. This endoscopic approach also allows for the visualization of foraminal and intradiscal pathology that is not appreciated by the traditional approach. The correlation of these ﬁndings with pain generation may open the door to a better understanding of the degenerative process causing lumbar disc herniations; our concept of surgical intervention that encourages patient selection for earlier intervention may evolve as well.
We sought to construct a general methodology for objectively quantifying the learning curve associated with any surgical technique and to determine the number of cases needed to achieve a success rate of 90% for the technique of transforaminal endoscopic lumbar discectomy. To our knowledge, no other studies have observed the learning curve of endoscopic lumbar discectomy by transforaminal approach.
Endoscopic spine surgery has evolved gradually through improvements in endoscope design, instrumentation, and surgical techniques. The ability to visualize and treat painful pathology endoscopically through the foramen has opened the door for the diagnosis and treatment of degenerative conditions of the lumbar spine (from T10 to S1). Other endoscopic techniques for treating a painful disc have been focused on a posterior approach and has been compared with micro–lumbar discectomy.
These procedures have not been more effective than open microdiscectomy but are less invasive, have less surgical morbidity, and allow for more rapid surgical recovery. Spinal decompression and fusion was the fallback procedure when nonsurgical treatment or discectomy failed to relieve sciatica and back pain. Foraminal endoscopic surgery, however, provides a truly minimally invasive alternative approach to the pathoanatomy of the lumbar spine because it preserves the multifidus muscle, maintains motion, and eliminates or, at worst, delays the need for fusion.
Throughout much of the late twentieth century numerous surgical specialists have pursued less invasive techniques for the treatment of surgical problems. The specialties of interventional radiology, laproscopic general surgery, arthroscopic orthopaedic surgery and minimally invasive vascular surgery have seen such rapid growth that there are now fellowships in each field. The patient benefits from these less invasive techniques have been well documented throughout the literature and the gold standard for numerous procedures has changed significantly within the last twenty years.
The technique and equipment for performing posterolateral percutaneous endoscopic lumbar discectomy has evolved dramatically in the past five years. The current level of proficiency brings endoscopic capabilities close to the capabilites of conventional transcanal open operations. The foraminal approach can be used not only for herniated discs, but also for degenerative conditions of the lumbar spine.
The advantage of the foraminal endoscopic technique is the ability to reach, visualize, and treat certain intradiscal and foraminal pathologic lesions without destabilizing the posterior muscle column and facets. Intradiscal visualization is enhanced by chromo-discography combining non-ionic radiographic agents (isovue-300) with indigocarmine dye. This blue dye differentially stains degenerated nucleus.
The learning curve is steep, but once mastered, the surgeon is able to reach any pathologic lesion in the foramen, including noncontained disc herniations, foraminal stenosis, facet cysts, and annular tears.
The intervertebral disc, an important supporting structure of the spinal column, is implicated as a major source of low back pain and sciatica. The pathogenesis of disc degeneration and herniation is complex and multifactorial, but clearly outlined and documented by Wolfgang Rauschning’s work illustrating the patho-anatomy of degenerative disc disease and degenerative conditions of the lumbar spine.
Most disc herniations are not the result of an acute event, but an accumulation of several insults to the spine that lead to degeneration, annular tears, and eventual disc herniation. There are several theories of disc degeneration including mechanical, chemical, age-related, autoimmune and genetic. Within the mechanical theory, the following types of abnormal loads have been proven experimentally to cause disc injury: torsion, compression, repetitive compressive loading in flexion, hyper flexion, and vibration.
Chapter “Arthroscopic Decompression”
Foraminal Endoscopic Surgery of the Lumbar Spine
Endoscopic disc surgery is evolving rapidly due to improvements in surgical technique, endoscope design, and instrumentation. These third generation systems with excellent optics give the endoscopic spine surgeon the ability to probe spinal anatomy in a conscious patient and evaluate the pathologic process causing the patient’s pain. Now that spinal endoscopy can be performed, conditions previously not even considered for surgery may be evaluated and managed.
Patients previously not candidates for traditional surgery may find relief with endoscopic spine surgery directed toward the pain generator. Our understanding of discogenic back is enhanced by diagnostic and surgical endoscopy of the lumbar spine, as endoscopic visualization of pathologic lesions not previously seen with traditional techniques are increasing our understanding of the pain generators in the lumbar spine.
Endoscopic disc surgery is evolving rapidly because of improvements in surgical technique, endoscope design, and instrumentation. These third-generation systems with excellent optics give the endoscopic spine surgeon the ability to probe spinal anatomy in a conscious patient and evaluate the pathologic process causing the patient’s pain. Now that spinal endoscopy can be performed, conditions previously not even considered for surgery may be evaluated and managed.
Patients who previously were not candidates for traditional surgery may find relief with endoscopic spine surgery directed toward the pain generator. Our understanding of discogenic back pain is enhanced by diagnostic and surgical endoscopy of the lumbar spine, as endoscopic visualization of pathologic lesions not previously seen with traditional techniques is increasing our understanding of the pain generators in the lumbar spine.
More than Twelve years have passed (1991) since I learned and adopted Arthroscopic Microdiscectomy from pioneer endoscopic spine surgeon Parviz Kambin, who, along with Sadahisa Hijikata, first established the technique for percutaneous nucleotomy in the early 1970’s. A cadaver dissection of the traditional posterior anatomy of the lumbar spine compared with the foraminal anatomy clearly illustrates the feasibility and advantages of the foraminal approach to the lumbar disc.