THE THORACIC AND LUMBAR SYMPATHOLYSIS

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.
 

TECHNIQUE

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.
Levels L1-L2 and L3-L4 are punctured. The spread is as always evaluated with  3 cm3 of xylocaïne diluted with  iodine tracer product. This must remain in the retroperitoneum and not spread to the psoas sheath for example.
Then 5 to 10 ethanol cm3 are injected on each level. Only one side can be treated and it is necessary to wait 6 to 8 weeks before treating the other side in order to reduce the risk of orthostatic hypotension. Retroperitoneal  ethanolization  is usually painless, a feeling of immediate heat, in the treated lower limb, can be felt by the patient.
The intervention lasts approximately 30 to 40 minutes.
 

COMPLICATIONS

The possible complications of the neurolysis of the thoracic sympathetic chain are the pneumothorax and haemorrhaging caused by the puncture of an intercostal artery, a wound of the nerve at the lateral foramen if the bevel of the needle is placed higher than recommended, an intravascular injection of ethanol or xylocaïne or a spreading of the ethanol in subarachnoidian space.

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.
All these complications were due to neurolysis under scopic control and are avoided today by a rigorous SCAN control,  before, during and after neurolysis.
 

INDICATIONS

The neurolytic block of the sympathetic nerve chain from T2 to T8 is indicated among patients affected by a tumoral development  reaching the upper 2/3  of the posterior mediastinum (ex : oesophageal cancer, pulmonary cancer with spreading to the mediastinum) and presenting pains which are not relieved by antalgic treatment.
 

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.
 

CONCLUSION

The simplicity of this method practised without premedication, in outpatients, makes it possible to avoid general anaesthesia, the traumatism of surgery and the complications of lying in bed during hospitalization.
Lastly, the financial saving made in comparison to surgical sympathectomy is significant.