spinal cord stimulator (medtronic mdt)
For pain in the lower extremities and lower back, the
stimulator electrode implant (medtronic - mdt) is placed between T9 and L1, over the lower end of
the spinal cord. Placement of the spinal cord stimulator implant is usually done with a local anesthetic,
and intravenous sedation.
The patient is brought to the operating room, and
rolls over onto his/her abdomen. The patient is kept in as comfortable
a position as possible. The anesthesiologist gives intravenous
sedation, and the surgeon injects a good amount of "numbing" local
anesthetic medicine, under the skin, and deeper as the surgery progresses.
Bone is removed (lamina) at the appropriate level, to
facilitate placement of the spinal cord stimulator implant paddle
electrodes (medtronic - mdt) behind the dura (covering of
the spinal cord). The spinal cord stimulator implant electrodes are
now connected to a pulse generator (medtronic - mdt), and with the patient awake, stimulation
is begun. Now the patient can determine whether a certain pattern of
firing of the implant electrodes successfully relieves his/her
pain. The patient will often describe a good feeling. Because of
the design of the medtronic implant electrodes (medtronic - mdt), there are actually four contact
points on each side, and this provides the ability to cover varying amounts
of spinal cord within the area of stimulation. Seen in the x ray
(taken from a C arm fluoroscopy unit in the operating room), the two columns
of four implant electrodes are seen overlying the L1 vertebral body (note: the
lowest level in the thoracic spine (T12) has ribs coming off of it).
One can determine, through the stimulator box, which electrode will be
positive (+) and which will be negative (-). In addition, the
amplitude and frequency of the pulses to the spinal cord stimulator implant
(medtronic - mdt) can be set.
The leads are brought out through an incision several
inches away from the open surgical site. The patient goes home with
the stimulator attached through a wire fed through the skin. He will
determine over the next several days, whether or not the device provides
If the patient feel the relief of pain is good, he
will come into the hospital several days later, and the battery pulse
generator (medtronic - mdt) will be permanently implanted within a pocket under the skin,
usually below the rib cage. This procedure is done with the patient on
his/her side, and a general anesthetic is used. The patient does not
need to be awake because the position of the stimulating electrodes will not
Seen below are the electrodes and battery pulse
generators (medtronic - mdt) (on left), and the electrodes, battery pulse
generators and connecting cable (on the right).