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1.
Percutaneous Discectomy Devices
2. Conclusion
Back
pain related to a herniated intervertebral disc is one of the most
common causes of chronic disability. Although many cases of acute
low back pain will resolve with conservative therapy, a surgical
decompression is often considered when the pain is unresolved after
conservative therapy. Historically, open surgery has been used to
treat radicular pain, by either discectomy; e.g. removing part of
the abnormal intervertebral disc or by decompressive laminectomy;
e.g. resecting portions of the lamina to relieve the pressure on
the spinal canal and nerve roots. Surgical success rates have been
in excess of 90%. Decompressive surgical techniques have advanced
to the point where procedures utilizing laser or radiofrequency
energy are performed through smaller incisions or via endoscopy.
Percutaneous
disc decompression has been used in the treatment of herniated discs
for over 40 years and in over 500,000 patients. A variety of techniques
have been used to decompress discs, including chemical, mechanical
and thermal/heat (radiofrequency and laser) methods. Early procedures
showed conclusively that percutaneous disc decompression effectively
relieves pain for appropriate patients. Intradiscal electrothermal
anuloplasty (IDET) is another minimally invasive approach to low
back pain in which a heated element is used to treat pain thought
to arise from the surrounding annulus. This procedure has met with
limited clinical success.
The
Stryker Dekompressor (Stryker) and Nucleoplasty (Arthrocare) are
examples of FDA approved percutaneous discectomy devices. Percutaneous
disc decompression has been shown to treat symptomatic patients
with contained herniated discs. The ideal patient would meet the
following common criteria for any of the techniques considered.
Inclusion
criteria include: radicular symptoms; e.g. leg pain greater than
back pain, CT or MRI evidence of contained posterior-lateral disc
protrusion and failed epidural/selective nerve root block (included
to ensure that patients are given the opportunity to respond to
conservative care), failed conservative therapy for 3 months and
discography positive for concordant pain.
Exclusion
criteria include: disc height of less than 50%, evidence of severe
disc degeneration, spinal fracture, spinal tumor or spinal stenosis.
Contraindications
include: traumatic spinal fracture, infection, tumor, pregnancy
and severe co-existing medical disease(s).
The
procedure is not indicated for the treatment of pain originating
from structures other than herniated discs. Patients with a free
disc fragment, severe bony stenosis, severely degenerative discs
or with severe and rapidly progressing neurological deficits are
excluded.
Potential complications include: infection, bleeding, nerve damage,
worsening of pain, paralysis, idiosyncratic reaction, anaphylaxis
and death.
The
procedure is performed under local anesthesia or conscious sedation
to allow patient monitoring for signs of segmental spinal nerve
irritation. No general anesthetic is required. Once the needle is
inserted into the disc, the procedure itself takes only a few minutes.
The entire procedure lasts less than one hour and the patient is
able to leave shortly afterwards. There is typically little pain
after the procedure and it is easily managed with analgesics. Patients
are advised to avoid lifting and strenuous exercise and may go back
to sedentary work after one week. Patients with more physically
demanding occupations may need to wait longer to recommence their
daily activities. Additional physical therapy may prove beneficial
in the recovery period.
Percutaneous
discectomy may result in a decrease in anesthesia time, procedure
time and recovery time, a lower complication and morbidity rate
and a significant reduction in post-operative spinal instability.
Percutaneous discectomy has demonstrated the potential to produce
equivalent, or even better, outcomes than conventional surgery in
a procedure that is permanent, simpler, quicker, less traumatic
with less perineural scarring and post-operative fibrosis and has
faster recovery times. Clinical results are very promising and patients
can generally expect rapid and sustained pain reduction.
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Percutaneous
Discectomy Devices
DISC
Nucleoplasty (Arthrocare) - www.nucleoplasty.com
DISC
Nucleoplasty uses a unique plasma technology, called coblation,
to remove tissue from the center of the nucleus pulposus. During
the procedure, the DISC Nucleoplasty probe is introduced through
a needle and placed into the center of the disc where a series of
channels are created to remove tissue from the nucleus.
Access
to the disc is made through a 17 gauge (cervical or thoracic) or
19 gauge (lumbar) cannula with an obturator stylet using an anterior-lateral
approach in the cervical spine or a posterior-lateral approach in
the thoracolumbar spine. While monitoring the patient, the probe
is advanced into the disc. As it is advanced, the coblation plasma
mode is activated and tissue along the path of the device is removed
via molecular dissociation. Tissue is turned into gas, which exits
the disc via the introducer cannula. After the first channel is
created, the probe is rotated clockwise, and re-advanced creating
another channel. Approximately six channels are made in total, depending
on the desired amount of tissue reduction.
Since
its first application in July 2000, the Nucleoplasty procedure has
been used to treat over 35,000 patients worldwide. Initial outcome
studies show high success rates. Average pain reduction is significant,
55-60%. Patient satisfaction is high, about 90%, largely due to
the relative ease of the procedure, the lack of a painful rehabilitation
period and the fact that the procedure does not preclude any subsequent
procedure such as open surgery. Although long-term data is not yet
available, the early studies show pain relief is sustained up to
two years post-procedure.
The
Dekompressor Percutaneous Lumbar Discectomy Probe (Stryker) www.dekompressor.com
The
Dekompressor utilizes a self contained motorized drill for removal
of nucleus pulposus through a small channel under fluoroscopic guidance.
Superficial, deep and intradiscal anesthesia is provided with local
anesthetics. The cannula is advanced into the disc space via a posterior-lateral
approach into the intervertebral disc space. As the device is activated,
the drill bit disrupts nuclear tissue and mechanically draws material
to a collection chamber at the base of the motor assembly. Patients
rarely experience any discomfort during the procedure. The Dekompressor
is capable of aspirating disc material from the intervertebral disc
space of the lumbar, thoracic and cervical spine.
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Conclusion
In
conclusion, newer techniques in interventional pain offer the potential
to significantly reduce the morbidity and mortality of major neurosurgical
procedures of the spine.
Percutaneous
discectomy, a new minimally invasive technique, may prove useful
in relieving the pressure on spinal nerve roots by small herniated
intervertebral discs. The procedure has demonstrated the potential
to produce equivalent, or better, outcomes than conventional spinal
decompressive surgery. It is a procedure that is simpler, quicker,
less traumatic with less perineural scarring and post-operative
fibrosis and has faster recovery times than the open surgical equivalent.
Clinical results are very promising, but long term outcomes are
pending.
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