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Lumbar laminectomy (open decompression) is a surgical procedure that is
performed to alleviate pain caused by neural impingement (pressure on the
nerves). The surgery removes a small portion of the bone over the nerve
root and/or disc material from under the nerve root to give the nerve root
more space and an opportunity to heal.
A laminectomy is effective for decreasing pain and improving function
for patients with lumbar spinal stenosis. Spinal stenosis is
a condition that usually occurs in elderly patients, and is caused by
degenerative changes that result in enlargement of the facet joints. The
enlarged joints then place pressure on the nerves, and this pressure may be
effectively relieved with a lumbar laminectomy.
Laminectomy surgical procedure
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A two-inch to five-inch long incision is
made in the midline of the back
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The left and right back muscles (erector
spinae) are dissected off the lamina on both sides and at multiple levels,
allowing the surgeon access to the nerves
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The facet joints, which are directly over
the nerve roots, may then be trimmed to give the nerve roots more room
Following the operation patients are in the hospital for one to three
days. The patient's ability to return to normal activity is largely
dependent on his or her pre-operative condition and age. Patients are
encouraged to walk directly following the procedure. It is recommended that
patients avoid excessive bending, lifting or twisting for six weeks in
order to avoid pulling on the suture line before it heals.
Laminectomy success rate
Laminectomy surgery has a favorable success rate. Following surgery
approximately 70% to 80% of patients have significant improvement in their
ability to perform normal daily activities and a noticeably reduced level
of pain and discomfort.
Results from this surgery are much better for relief of leg pain caused
by spinal stenosis than for relief of lower back pain. Lumbar spinal
stenosis is often created by the facet joints becoming arthritic,
and much of the back pain is from the arthritis. Although removing the
lamina and part of the facet joint can create more room for the nerve roots
it does not eliminate the arthritis. Unfortunately, the symptoms may recur
after several years as the degenerative process that originally produced
the spinal stenosis continues.
In certain instances the success rate of a decompression for spinal stenosis
can be enhanced by also fusing a joint. Fusing the joint prevents the
spinal stenosis from recurring and can help eliminate pain from an unstable
segment. Fusion surgery is especially useful if there is a degenerative
spondylolisthesis associated with the stenosis. Generally speaking, if
there is multi-level stenosis from a congenitally shallow canal a fusion is
not necessary; however, if the stenosis is at one level from an unstable
joint (e.g. degenerative spondylolisthesis), then a decompression surgery
with a fusion is a more reliable procedure.
Laminectomy risks and complications
The potential risks and complications with a laminectomy procedure
include:
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Nerve root damage (1 in 1,000) or
bowel/bladder incontinence (1 in 10,000). Paralysis would be extremely
unusual since the spinal cord stops at about the T12 or L1 level, and
surgery is usually done well below this level.
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1 to 3% of the time a cerebrospinal fluid
leak may be encountered if the dural sac is breached. This does not change
the outcome of the surgery, and generally a patient just needs to lie down
for about 24 hours to allow the leak to seal.
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Infections happen in about 1% of any
elective cases, and although this is a major nuisance and often requires further
surgery to clean it up along with IV antibiotics, it generally can be
managed and cured effectively.
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Bleeding is an uncommon complication as
there are no major blood vessels in the area.
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In approximately 5 to 10% of cases,
postoperative instability of the operated level can be encountered. This
complication can be minimized by avoiding the pars interarticularis during
surgery, as this is an important structure for stability at a level.
Weakening or cutting this bony structure can lead to an isthmic spondylolisthesis
after surgery. Also, the natural history of a degenerative facet joint may
lead it to continue to degenerate on its own and result in a degenerative
spondylolisthesis. Either of these conditions can be treated by fusing the
affected joint at a later date.
General anesthetic complications such as myocardial infarction (heart
attack), blood clots, stroke, pneumonia or pulmonary embolism can happen
with any surgery. Although in the general population these complications
are rare, laminectomy surgery for spinal stenosis is generally done for
elderly patients and therefore the risk of a general anesthetic
complication is somewhat higher.
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