Treatment Options for Ruptured (Herniated) Discs in the Low Back

Non-Surgical Treatment
The mainstay of therapy for herniated lumbar disc is conservative treatment, i.e., non-surgical. This is because in the majority of patients the symptoms resolve or subside to a level allowing normal activity within 4-6 weeks. There are numerous non-operative treatment modalities. Most encompass a combination of bed rest, physical therapy, chiropractic care, and medication. Analgesics or muscle relaxants can sometimes help relieve pain. The most commonly prescribed drug therapy involves NSAIDS (non-steroidal anti-inflammatory drugs). These reduce inflammation that may be the causative factor underlying nerve root pain. Proper exercise can also help prevent back problems and is included in many treatment regimes. A physical therapist or chiropractor can work to create an individualized exercise plan to best suit each patient. The vast majority of patients are treated with nonoperative techniques. Surgery should only be considered when aggressive nonoperative treatment has failed.

Spine Surgery
When non-operative treatment fails to relieve symptoms, surgery may be indicated. Careful evaluation is done before any surgery. The type and timing of any operation depends on many factors: Type and location of herniation, severity of the disorder, amount of nerve compression, previous operations, etc. Most spine surgeons use the most advanced technology and the least invasive approach when applicable. Conventional discectomy surgery for the removal of a herniated lumbar disc is one of the most commonly performed procedures in the United States. An incision is made vertically along the midline of the back, usually about 2 inches long. Paraspinous muscle is stripped off the spinous process and the lamina. A small window is created in the lamina overlying the disc herniation. The nerve root is identified and gently retracted to expose the offending disc herniation. The disc material is then removed and wound is closed in a way that restores the normal anatomic layers.

Post-operative recovery is relatively fast. Relief from nerve root compression is often immediate, but back pain associated with the surgical approach can be intense. Patients are up walking the same night or the next morning after the surgery, and usually discharged home in 2 to 3 days. The vast majority of patients experience significant pain relief. Recovery of motor and sensory function may be variable.

Evolution of Posterior Minimally Invasive Spine Surgery Technical and research developments have provided new treatment modalities for the patient with spinal disc disease since the disease's description by Mixter and Barr in 1934.

Percutaneous Treatment Options
Percutaneous techniques (performed through the skin) derive their origins and continued success from these medical advances and patients' desire for a less invasive yet effective therapy for this common ailment. Advances in percutaneous techniques and endoscopy have allowed for a rapid expansion of interest and work in the field of minimally invasive discectomy that complements the current popularity of outpatient surgery. Percutaneous techniques include chemonucleolysis, manual and automated discectomy, and endoscopic-assisted discectomy. These approaches, although diverse in their methodology, share some common, desirable qualities; for example they: i. may be performed under local anesthesia; ii. afford a minimal amount of soft-tissue dissection; and iii. do not preclude the use of open surgery in the future.

Chemonucleolysis
Intravenous pain injections in rabbits was found to result in floppy ears from a transient loss of cartilage. This discovery was cleverly applied to disc disease, and found to dissolve the nucleus pulposus in humans. The initial experience was presented in 1964. Its use has been the subject of much controversy in subsequent years.

Percutaneous Nucleotomy
The first report of percutaneous discectomy was in 1975, using a dorsolateral approach to the disc. Although the dorsolateral approach was the most widely used, a more lateral, retroperitoneal approach (behind the membrane lining of the abdominal or pelvic cavities) was proposed. This was not widely accepted due to the risk of damage to retroperitoneal structures.

The next significant improvement in the technique came in the 1980s with the use of an automated discector, giving rise to the automated percutaneous lumbar discectomy. The automated discector is a suction shaver that can perform controlled removal of disc material. The laser has been applied with some success using a similar approach. Although most of the experience has been in the lumbar spine, a series of cervical cases has been reported, but is not the focus of this chapter. Controversy and criticism surround the many reports concerning percutaneous nucleotomies. These techniques may all be considered indirect techniques because they remove the central disc but do not directly address the offending pathology causing nerve root compression.

Central disc removal reduces the pressure within the disc space, an effect casually known as "popping the balloon". Furthermore, it creates a defect in the annulus fibrosus through which disc material may herniate in the future. This herniation is directed away from the nerve root. Also, with an indirect approach to the pathology, scar formation around the nerve roots may be minimized. The crux of the medical debate is regarding these techniques' efficacy. Several studies have shown that percutaneous nucleotomy, whether automated or manual, does not have the same success rate as open lumbar discectomy.

Endoscopic Discectomy
The marriage of the endoscope with the percutaneous technique was logical progression. Percutaneous evaluation of the spinal canal and endoscopic visualization of disc pathology were described in 1938. Endoscopy was used to improve the blind technique of percutaneous nucleotomy by allowing the surgeon to confirm instrument placement and to observe disc removal from within the disc space. The next limitation to overcome in the case of a percutaneous procedure was the inability to directly remove the herniated disc from beneath the nerve root in the spinal canal. Intradiscal approaches could only indirectly remove herniated disc material by pulling it down into the disc space. Endoscopic approaches with a working channel were developed to directly visualize and address the disc at the nerve root level.

Direct Endoscopic Approaches
The desire to expand the utility of endoscopic techniques led to the development of direct endoscopic approaches. With these techniques, compressed nerve roots could be directly decompressed. The endoscopic transforaminal approach (also termed the foraminoscopic approach) was the first percutaneous approach directly visualize the pathology during nerve root compression. The epidural space and the nerve root can be seen through the neural foramen. A percutaneous approach with a small fiberoptic scope and 6-mm working channel is performed. The nerve root is identified and disc material that is compressing the root is removed through the working channel. The technique seems particularly well suited for the treatment of far lateral discs herniation, although this represents less than 10% of symptomatic disc ruptures. Limitations include the small size of the scope and working channel, which can preclude the removal of large herniated disc fragments. Also, the neuroforamen itself can be quite small, limiting access to the compressed nerve root.

The MED System
The endoscopic revolution has impacted virtually every surgical field. The benefits of small incisions, limited tissue disruption, enhanced visualization and illumination, shorter hospital stays, and faster recovery times have been fruits of these changes. In the case of lumbar discectomy, the primary objective is to decompress the affected nerve root. The compressed nerve must be left fully decompressed and freely mobile. This may require extensive bony decompression, nerve root manipulation, and/or removal of the herniated nucleus pulposus. Prior minimally invasive techniques for lumbar discectomy, despite their popularity, have not been able to reproducibly achieve this goal.

The objective of the MED System is the same as conventional open surgery - to decompress the nerve root. This is accomplished by applying open surgical techniques through a tubular retractor under endoscopic visualization. For the first time, a laminotomy, medial facetectomy, foraminotomy, nerve root retraction, and discectomy can be performed endoscopically. In so doing, the MED System combines the reliability of conventional open surgery with the advantages of a minimally invasive technique.