Lumbar Sympathetic Block
Lumbar sympathetic block may be indicated for painful conditions involving the pelvis or the lower extremities, and possibly for some patients with peripheral vascular disease.
The lumbar sympathetic chain contains three to five ganglia and is a continuation of the thoracic chain. It also supplies sympathetic fibers to the pelvic plexus and ganglia. The lumbar sympathetic chain ganglia are in a more anteromedial position to the vertebral bodies than the thoracic ganglia, and are anterior to the psoas muscle and fascia. The lumbar chain is usually posterior to the vena cava on the right but is just lateral to the aorta on the left.
A single-needle technique at the L3 level on either side is most commonly employed with the patient either prone or in a lateral position ( Figure 47–22). The needle is inserted at the upper edge of the spi-nous process and is directed above or just lateral to the transverse process of the vertebrae (depending on the distance from the midline). Fluoroscopic guidance with injection of radiopaque contrast prior to local anesthetic injection is often used.
Complications include intravascular injection into the vena cava, aorta, or lumbar vessels and somatic nerve block of the lumbar plexus. In particular, the genitofemoral nerve may be blocked.