Over the years, interest in Minimal Access Spinal Technologies has increased dramatically.
The potential benefits of small incisions, limited tissue disruption and
visualization have been the incentive to pursue these technologies. 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 herniated nucleus pulposus.
This can be accomplished by applying open surgical
techniques through a tubular retractor under microsurgery visualization. A laminotomy, medial facetectomy, foraminotomy, nerve root retraction
and discectomy can be performed microscopically. In so doing, the METRx®
System combines the reliability of conventional open surgery with the advantages
of a minimally invasive technique.
The quest for enhanced clinical results through the utilization of innovative
new technologies will continue to alter the way in which we deliver patient
care. With proper patient selection, the technique for the METRx® System
allows for adequate nerve root decompression and provides the benefits
of minimally invasive techniques.
Features and Benefits
With the METRx® System, spine surgeons are able to remove herniated
or "slipped" discs in the lumbar spine with a minimally invasive technique.
Over the last 10 years, many of the surgical sub-specialties in Orthopedics
and Neurosurgery have used fiberoptic video cameras and tools
to assist them in performing surgery with much smaller incisions and less damage
to the surrounding tissue. Most people are familiar
with this type of technology in the form of "arthroscopic" surgery,
which allows orthopedic surgeons to look inside joints like the knee and operate
through very small incisions.
What type of Spine Surgery is the METRx® System Used For?
The METRx® System was designed in order to provide spine surgeons with
a way of removing herniated intervertebral discs in the lumbar spine that are
putting pressure on the spinal nerve roots and causing pain. Herniated discs
occur because the discs that act as shock absorbers between the bones of the
spinal column become stiff and less flexible as we grow older. Discs that lose
their flexibility can rupture and cause neck pain and back pain. A part of the
inside of the disc can herniate or leak out through a tear in the ligaments
that surround the disc, pressing on the spinal cord or on the nerves that travel
out to the arms and legs.
A herniated disc can be responsible for a pain that is felt in the neck or
back, but the pressure that the herniated disc puts on the spinal cord or the
nerve roots can cause pain in the arms or legs and sometimes can even cause
problems with the way the spinal cord normally functions. If a herniated disc
is pinching a nerve in the neck, most people will have persistent neck pain,
often with numbness in the arms and hands. If a herniated disc is pinching a
nerve in the lower back, then most people will have persistent low back and
buttock pain, with numbness and tingling in the legs and feet.
When the symptoms of a herniated disc do not respond to physical therapy, medications,
or improve with time, then surgery can be an option. This type of spine surgery
is called a "discectomy" and it is used to remove the part of the
herniated disc that is pinching or putting pressure on the nerve roots in order
to relieve the pain and numbness. With traditional disc surgery, spine surgeons
make an incision in the center of the back or neck at the same level as the
herniated disc and then strip the muscles of the back away from the bones of
the spinal column in order to be able to see the area where the disc has herniated.
Once the herniated disc has been removed, the muscles are put back in place
and the surgeon closes the incision.
How is surgery with the METRx® System Different?
With the METRx® System, surgeons can perform this type of discectomy
surgery with a type of muscle splitting technique that minimizes the
amount of muscle damage that is necessary in order to be able to see where the
herniated disc is located and remove the herniated fragments while protecting
the nerve roots and spinal cord.
How does the METRx® System Work?
The main advantage of the METRx® system in comparison to a tradition discectomy
is a smaller incision and less damage to the muscles of the spinal column. This
advantage is achieved by allowing the surgeon to expose the area where the herniated
disc is located without making a large incision. A discectomy that is done with
the METRx® system begins with the surgeon precisely localizing the level
of the herniated disc with a very small needle that is inserted through the
muscles of the back down to the area where the disc fragments are located. The
correct position of this needle is confirmed with a special type of X-ray machine
that is used in an operating room called a flouroscope. After the correct position
of the needle has been confirmed with fluoroscopic guidance, a series of soft-tissue
dilators are used to create a small tunnel that measures 16mm in diameter (less
than ¾ of an inch) through the muscles of the back so that a hollow tube
can be inserted down to the level of the spinal column. This tube, which is
called a tubular retractor, contains a very special video camera with a magnifying
lens and a fiberoptic light source that illuminates the tissues and relays the
images to a separate video screen so that the surgeon can operate.
Once the tubular retractor is in the correct place and the surgeon is able
to visualize the area where the herniated disc is located, he or she is able
to remove the fragments of the disc with instruments that fit down the
inside of the tubular retractor. When the operation is over, the tubular retractor
is removed, and the incision, which is less than an inch in length, is closed
and the wound is allowed to heal.
It is important that you discuss the potential risks, complications, and benefits of METRx® System with your doctor prior to receiving treatment, and that you rely on your physician's judgment. Only your doctor can determine whether you are a suitable candidate for this treatment.
