These techniques, which have been
used for over forty years in the treatment of obliterating chronic arteriopathy
of the lower limbs for the lumbar level, have been in the news again since
the appearance of tomodensitometry which allows for a greater safety during
therapeutic treatment in particular in the cases which interest us.
After evaluation of the spread of 3 cm3 of iodine tracer product of diluted with xylocaïne (scan control), 3 to 5 ml of ethanol to 96 % can then be injected. The accidental puncture of the vertebral body, the disc or a vascular structure are avoided by a progression controlled by scan.
The lumbar sympathetic chain presents an anterolateral situation of the vertebral body inside the psoas muscle and behind the aorta and vena cava. The lumbar sympathetic chain located in the fatty retroperitoneal space, can't be seen, its position is easily locatable : in front of the anterolateralcurve of the rachis, in front of the inner surface of the psoas, in inside the urethra, and, behind the lower vena cava on the right and the aorta on the left.This space is narrowed at L2 level, and more extended at L4 level.
The sympathetic chain is reached,
initially on L2 level, through a posterolateral approach, the metal reference
mark selected as a cutaneous entrance point must allow the needle
to avoid the transverse apophysis, the vertebral body, the kidney, the
urethra, the digestive structures. Tomodensitometry makes it possible
to evaluate the obliqueness of the needle compared to the cutaneous layer,
and the depth of the injection.
The possible complications of neurolysis of the lumbar sympathetic chain are the intravascular injection of the ethanol, injection into an intervertebral disc, or the vertebral channel in contact with the ureters or one of the neighbouring organs.
The other major complication is the
genito-femoral neuralgia caused by the spread of the ethanol in contact
with the nerve along the psoas sheath.
The neurolytic block of the sympathetic
lumbar chain is indicated for pains of the tenesmus type pains, those related
to cancer of the internal pelvic organs or the metastatic ganglionic infiltrations
of the retroperitonal lumbar region. .
The nociceptive tracts coming from
the cervical collar and the uterus follow the sympathetic nerve lumbar
chain. Thus in the case of refractory pains originating in the uterus a
bilateral sympatholysis can be indicated.