Microsurgical Discectomy
by W. Bradford DeLong, MD, FACS
Introduction
Your Spinal Column
Your spinal column is made up of a number of separate vertebrae and it supports your body. It also
provides a protective channel for the spinal cord and the nerves which move your muscles and carry
sensation back to your brain from the outside world.
This protective channel is called the spinal canal. There is an opening on each side of the spine at each
spinal level. A spinal nerve runs through each of these openings and carries nerve impulses to muscles or
carries information to the brain from the sensory organs in the skin, muscles, ligaments, and internal
organs. Normally, there is plenty of room for the nerves and spinal cord in the spinal canal, and plenty of
room for the nerves to run through the openings in the side of the spinal column.
Herniated disc
An intervertebral disc sits between every two bones of the spinal column, and cushions the movement of the
spine. It is made of tough fibrous material, sort of like the tissue on the breast bone of a chicken. The disc
can break down, so that pieces of the fibrous tissue push backward into the spinal canal. If this happens,
sometimes they push against the nerves. In the neck, the piece of disc can also push against the spinal
cord.Pressure on the nerves can cause weakness, numbness, or pain in the arms or legs. Pressure against
the spinal cord can cause weakness, numbness, and problems with coordination in the arms or legs.
Sometimes calcium deposits can build up inside the spinal canal or nerve channels and narrow the canal or
channels. These deposits are called "spurs" or "osteophytes." This narrowed condition is called "spinal
stenosis," and it can cause symptoms very similar to the symptoms of a herniated disc.
Sometimes a combination of disc herniation and spinal stenosis develops and both problems create the
symptoms. For additional information concerning herniated discs and spinal stenosis, please see the other
Web Pages in this section: "Cervical Spinal Surgery" and "Spinal Stenosis."
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Symptoms of a Herniated Disc or Spinal Stenosis.
A herniated disc can cause pain in several ways. The most usual way is irritation of a nerve root by pressure
from the piece of the disc pushing against it. If the herniated disc is in the low back, the pain often seems to
be traveling down the leg, because that is where the irritated nerve is going.
In these cases, the person feels the pain in the area where the nerve ends up, not in the area where its
actually being irritated. This is called "sciatica," because the sciatic nerve is the big nerve that goes down
the back of the leg. When a disc breaks down, abnormal chemical products are created inside the disc.The
nerve can also be irritated and inflamed by these chemical products. That is why cortisone medication
placed around the irritated nerve can sometimes help the pain. Cortisone decreases inflammation. The pain
can occur from painful muscle spasm as the body tries to limit the motion of the spine. It can occur from
painful inflammation in the ligaments around the involved part of the spine. In the neck,bone spurs or
herniated discs can cause pressure on the spinal cord, with or without pain. This may result in progressive
problems with walking and a lack of coordination in the arms and legs.
Conservative Care Before Surgery
Most people who have symptoms from a herniated disc get better without surgery, provided they are
involved in a good program of conservative care. Effective conservative care can include physical therapy
with training in exercise and pelvic stabilization, along with certain forms of traction. It can include
chiropractic care with manual therapy and a good home exercise program.
Conservative care can include, in some cases, injections of medication to soothe the inflamed nerve roots. A
cortisone-type of medication can be placed directly inside the spinal canal or nerve channel. This is called an
"epidural injection" or "selective nerve root block" and soothes the nerves by relieving inflammation.
Injections to lessen chronic inflammation may also help if the pain is coming from painful ligaments around
the facet joints or the sacroiliac joints. It's usually a good idea to try a conservative program for a few
weeks before considering surgery. However, if the pain is severe or if the disc herniation is causing
weakness, you may want to have surgery sooner rather than later, especially if the conservative program
isn't giving you satisfactory relief of the symptoms.
Minimally Invasive Surgery
Laser Disc Decompression, Percutaneous Discectomy, or Arthroscopic Discectomy are called "closed"
operations, because the surgeon does not have to make a full incision to get at the disc. The middle part of
the herniated disc is removed with the instruments or with the Laser. Sometimes this type of surgery works
if the disc herniation is creating general pressure on the nerves and hasn't actually broken through the back
of the disc. These procedures are like arthroscopic surgery of the knee. When performing an Arthroscopic
Discectomy, the surgeon looks directly into the disc with an arthroscope. During Laser Disc Decompression
or Percutaneous Discectomy, the surgeon sees into the disc by means of fluoroscopy rather than by direct
vision through an arthroscope. However, with the Minimally Invasive Procedures the surgeon can't be sure
that he or she has been able to remove pieces of the disc which have become stuck in the spinal canal. To
do this reliably, the surgeon needs to be able to see directly into the spinal canal.
Microsurgical Discectomy
Microsurgical Discectomy, on the other hand, is an "open" operation, because the surgeon actually has to
make a small incision to get at the herniated disc. The "open" operations are generally more reliable than
the percutaneous "closed" ones, because the surgeon can see the disc fragments directly. The surgeon
moves the muscles of the back, and takes off a little bit of bone so that he or she can see into the spinal
canal
The involved nerve root is gently moved over to see the piece of disc that is pushing into the spinal canal.
The pieces of disc sticking up in the spinal canal are removed. Then loose degenerated disc material inside
the disc space is removed to lessen the chance that more of it could work its way out into the spinal canal
later. If the patient also has narrowing of the nerve channel from spinal stenosis, the part of the bone which
is pinching the nerve is removed to open up the nerve channel. This can be done very accurately by using
an operating microscope or magnifying loupes.
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The Operating Microscope
The modern operating microscope is usually mounted on a flexible stand, which lets the surgeon move it
around easily during the operation.
The lenses of the microscope are arranged so that the surgeon can see with both eyes and excellent lighting
deep into narrow openings. Without the microscope, it is harder for the surgeon to see into small incisions
because the eyes are normally too far apart to see with both of them at once into narrow openings. The
optical system of the microscope "squeezes" the surgeon's vision together, so that he or she can use both
eyes at once for good depth perception.
There are several reasons to use magnifying techniques for the disc operation. In the first place, the
operating microscope or magnifying loupes allow us to do a thorough excision of the herniated and
degenerated portions of the disc through a smaller incision. The disc herniation can be removed without
disturbing the muscles and ligaments very much.
This means that the individual is more comfortable after the surgery and that healing is faster. It also
means that the person feels better about the surgery afterward because the scar is smaller. He or she feels
less invaded.
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Operating microscope, balanced on an easily moveable stand. The optical system allows the surgeon to look
into a deep narrow opening with both eyes at once (stereoscopic viewing). The scope shines a very bright
light into the incision. The microscope is covered with a sterile plastic drape during surgery.
Bottom of the microscope optical system, showing the bottom lenses, which have the effect of "squeezing"
the surgeon's vision closer together so that he or she can see into a deep surgical incision with both eyes at
once.
Surgeon's viewing lenses (#1). Assistant's viewing lenses (#2). Observer's viewing lenses (#3). Surgeon's
hand control (#4) to move the scope and focus or zoom the optics. Stereoscopic objective lenses (#5).
A Brief Hospitalization
If you are having a Microsurgical Discectomy, you will come to the hospital or surgicenter the morning of the
surgery. You can expect to go home later that day, after the surgery. The nurses will get you out of bed and
help you walk around, to be sure you feel well enough to go home.
The Postoperative Program
The day after the surgery, you will start a simple exercise program. Approximately one week after the
surgery you will startworking again with your physical therapist for training in further exercises, general
conditioning, and low back stabilization. You can start back under the care of your chiropractor in a week or
so, too, though you shouldn't have low back adjustments for at least six months after the surgery. Your
general conditioning program should start within a week after the procedure. You should begin by briskly
walking 20 to 30 minutes per day. You should progress to a swimming program and/or easy cycling. You
should wait 2 to 3 months before engaging in more vigorous sports activities such as tennis, running, or
skiing. If things go as they usually do, you'll be able to go back to work 4 to 6 weeks after the surgery,
provided you do not have a job which requires significant lifting or other heavy physical work. If you have
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that sort of job, then you may have to wait 3 or 4 months before you go back to work.
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