What is Selective Dorsal Rhizotomy
What is Selective Dorsal Rhizotomy (SDR)?
SDR was first performed in the early 1900's, when complete
division of all the nerve roots to the lower limbs was performed.
Although this did lead to improvement in spasticity, it also caused
severe muscle weakness, as well as loss of skin sensation and
joint-position sense. The current technique, in which only those
nerve rootlets that contribute most to the spasticity are divided,
was introduced in 1978.
The current technique involves surgery in the lower back. The
procedure is performed under general anaesthesia and takes
around 4 to 5 hours. The technique we use is the same as
that developed in St Louis in the USA, which concentrates on the
lower part of the spinal cord - increasing its effectiveness and
reducing risk.
A skin incision is made in the upper lumbar spine. The spinal
canal is opened at only one level. An ultrasound probe is used to
identify the lower end of the spinal cord. The tough tissue
covering the spinal cord is opened and the lower end of the cord,
with the sensory roots attached, is identified. Each of the sensory
nerve roots is then subdivided into four or five rootlets. The
rootlets that contribute most to the spasticity are identified by
sequential stimulation and are subsequently divided.
Between 66% and 75% of these nerve roots are divided during
the procedure. The procedure is performed under the operating
microscope. At the end of the procedure, the cover of the spinal
cord is closed again, the back muscles are re-approximated and the
skin is closed with absorbable sutures.
(This information can also be found within the paediatric neurosurgery
webpages.) (Please note some photos taken prior to
facemask policies being in place in hosptials.)