Lumbar MicrodiscectomyMicroscopic Decompression
If a disc herniation in the low back results in significant nerve impingement, leg pain and sciatica may result. Lumbar discectomy (microdiscectomy) surgery is typically recommended for patients who have experienced leg pain for at least six weeks and have not found sufficient pain relief with conservative treatment (such as oral steroids, NSAID’s (non-steroidal anti-inflammatory drugs), and physical therapy). However, after three to six months, the results of surgery are not quite as favorable. If the pain is debilitating, it is not generally advisable to postpone surgery for a prolonged period of time (more than three to six months).
If after an appropriate course of physical therapy and rehabilitation, the patient has continued disabling pain, a lumbar discectomy may be suggested by the surgeon. In a lumbar discectomy, a small portion of the bone over the nerve root and/or disc material from under the nerve root is removed to relieve neural impingement and provide more room for the nerve to heal.
Importantly, since almost all of the joints, ligaments and muscles are left intact, the microdiscectomy procedure does not change the mechanical structure of the patient’s lower (lumbar) spine.
A lumbar discectomy is performed through a small (1 inch to 1 1/2 inch) incision in the midline of the low back.
- This procedure is performed with the patient lying face down. The back muscles are lifted off the bony arch (lamina) of the spine. Since these back muscles run vertically, they can be moved out of the way rather than cut.
- The surgeon is then able to enter the spine by removing a membrane over the nerve roots (ligamentum flavum), and uses either operating glasses (loupes) or an operating microscope to visualize the nerve root.
- Often, a small portion of the inside facet joint is removed both to facilitate access to the nerve root and to relieve pressure over the nerve.
- The nerves are gently retraced and the underlying disc removed.
- The patient is usually discharged either the same day or the next day after the procedure.
Discectomy as described above is the “gold standard” for treatment of disc herniation. This means that the standard open surgical discectomy is the treatment that has been shown to be the most effective, and the treatment to which all other treatments should be compared. The success rate of the microscopic discectomy approaches 95% in some patient series, in appropriately chosen patients.
Sometimes it is possible to relieve the pressure on a nerve with alternative procedures. These procedures include chemonucleolysis, percutaneous discectomy (with or without use of laser), or endoscopic discectomy.
Usually, a lumbar discectomy (microdiscectomy) procedure is performed on an outpatient basis with no overnight stay in the hospital or with one overnight stay in the hospital. It is usually a good idea to get out of bed and walk around immediately after recovering from anesthesia. Most patients go home within 24 hours after surgery, often later the same day. Once home, you should avoid driving, prolonged sitting, excessive lifting, and bending forward for the first four weeks.
A microdiscectomy surgery is actually more effective for treating leg pain (radiculopathy) than for lower back pain. The impingement on the nerve root (compression) can cause substantial leg pain, and while it may take weeks or months for the nerve root to fully heal and any numbness or weakness get better, patients normally feel relief from leg pain almost immediately after a microdiscectomy surgery.
The success rate for a microdiscectomy is approximately 90% to 95%, although 5% of patients may develop a recurrent disc herniation at some point in the future.
Following a microdiscectomy surgery, a program of stretching, strengthening, and aerobic conditioning is recommended to help prevent recurrence of back pain or disc herniation. Some surgeons restrict a patient from bending, lifting, or twisting for the first six weeks following surgery. However, since the patient’s back is mechanically the same, it is also reasonable to return to a normal level of functioning immediately following surgery. There have been a couple of reports in the medical literature showing that immediate mobilization (return to normal activity) does not lead to an increase in recurrent lumbar herniated disc.
Risks and potential complications associated with a lumbar discectomy (microdiscectomy) include:
- Dural tear (cerebrospinal fluid leak)
- Nerve root damage
- Recurrent disc herniation
- Bowel/bladder incontinence
These complications are quite rare. A dural tear, which occurs in 1% to 2% of these surgeries, does not change the results of surgery, but post-operatively the patient may be asked to lay recumbent for one to two days to allow the leak to seal.A recurrent disc herniation can occur in up to 5% of cases. This is where another piece of disc is pushed out from the nucleus through the opening in the annulus.