There are several different approaches that a surgeon will use to correct
spinal deformity such as scoliosis and kyphosis, including the traditional
posterior approach, an anterior approach, or both. The anterior approach
to scoliosis means that the surgeon will approach the spinal column
from the front of the spine rather than through the back.
Technically speaking,
the actual surgical incision and approach to the spine is through the
side of the chest or abdomen (stomach area) rather than down
the front of your body, as many patients would envision it. The anterior
approach allows surgeons to remove discs from the front of the spine,
place corrective spinal instrumentation and perform a spinal fusion.
The
choice of an open anterior approach to the spine is based on a number
of different factors including the type of scoliosis, location of the
curvature of spine, ease of approach to the area of the curve, and the
preference of the surgeon. There are certain types of scoliosis curves,
such as those involving the thoracolumbar spine, that are especially
amenable to the anterior approach. The surgeon may be able to fuse a
shorter segment of the spine using the anterior approach, preserving
more motion in the spinal column.
Anterior instrumentation
techniques can produce very powerful correction of spinal deformities.
However, this approach is more difficult than the standard posterior
approach.
The first thing
that happens after you enter the operating room is that your anesthesiologist
will help you to fall asleep. Once you are completely asleep, the anesthesiologist
will place a breathing tube to assist with your breathing during surgery,
establish a variety of catheters in your veins, and often an arterial
catheter in your wrist, all of which allow for monitoring of heart function,
blood pressure, fluid status, and the depth of anesthesia during your
operation. This allows the anesthesiologist to be sure that you remain
completely asleep during the operation. Once this is completed, the
patient is rolled onto their side, with the operative side facing up,
into what is termed the "lateral decubitus position."
The incision is made on the patient's side. Depending on the part of
the spine that requires correction, this may be over the chest wall
or lower down along the abdomen. The surgeon deflates the lung and removes
a rib in order to reach the spine. Most patients find it interesting
that the rib will grow back over time, especially if you are young.
For lower incisions, the surgeon may need to detach the diaphragm to
gain access to the spine, especially for thoracolumbar curves and those
in the lumbar spine.
Once the surface of the spinal column is exposed, the surgeon will often
remove the disc material from between the vertebra involved in the curve.
This will increase the flexibility of the curve and provide a large
surface area for spinal fusion. Disc removal is an important adjunct
to the anterior correction of scoliosis.
Placing instrumentation in the front of the spine completes correction
of the spinal deformity. This usually consists of placing a vertebral
body screw at each vertebral level involved in the curve. These screws
are then attached to a single or double rod at each level. A combination
of compression along the rod, and rotation of the rod will produce correction
of the spinal deformity.
After the final adjustment and tightening of the instrumentation, a
fusion is performed. The bony surface between the vertebral bodies is
roughened and bone graft is packed into the space between the vertebral
bodies. There are a variety of different sources for bone graft including
the removed rib, the crest of the pelvis, allograft bone, and other
bone substitutes.
The incision is closed and dressed. If the surgeon has been in the chest
cavity, then it will be necessary to place a chest tube through the
side of the chest to help keep you lung expanded after the surgery.