Thoracic; Sympathetic Ganglion, Injury Clinical Trial
Official title:
Incidence of Inadvertent Intercostal or Epidural Spread During Thoracic Sympathetic Ganglion Block
This study wants to identify the incidence of inadvertend intercostal or epidural spread of thoracic sympathetic block
Clinically, sympathetic blocks (SB) have been used widely to relieve the symptoms of SMP or
to differentiate between SMP and sympathetically independent pain. In order to an SB has a
diagnostic value, it requires the successful disturbance of the sympathetic activity for a
proper duration of time.
For the diagnosis of SMP using an SB, it is essential achieving complete interruption of the
sympathetic activity while preserving the sensory and motor function. The sympathetic trunk
at lumbar region runs on the anterolateral surface of the vertebral column from L1 to L4
levels, and deep to the medial aspect of the psoas major muscle. Therefore, the investigators
can hardly find epidural contrast spread during lumbar SB due to an anterior location of
lumbar sympathetic ganglion to the lateral vertebral body. However, frequent psoas muscle
injection can be encountered due to a close proximity of lumbar sympathetic ganglion.
In contrast to lumbar sympathetic ganglion, the thoracic sympathetic ganglion is not
separated from somatic nerves by muscles and connective tissue. Moreover, the upper thoracic
ganglion runs on the posterior surface of vertebral column with close proximity to adjacent
epidural region.
This difference of thoracic sympathetic ganglion leads to a frequent epidural and intercostal
spread if the investigators perform thoracic SB. Such spread to epidural and intercostal
space lowers the diagnostic value of thoracic SB. In addition, serious adverse outcome can be
encountered if neurolytic agent is injected into epidural or intercostal space for the
purpose of thoracic sympathectomy. Considering the diagnostic value and safety of thoracic
SB, evaluation of actual incidence of occurrence of intercostal and epidural spread is
important.
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