Lumbar Sympathetic Block

Abstract

Sympathetic nerve blocks are used to help with the diagnosis and treatment of sympathetically maintained pain. The lumbar sympathetic chain typically overlies the anterolateral aspect of the first through fourth lumbar vertebrae. The axons of the lumbar sympathetic preganglionic neurons exit the spinal cord through the ventral roots of the first four lumbar spinal nerves and send fibers through the white rami communicantes to the corresponding lumbar sympathetic ganglia. Postganglionic fibers then exit the chain to join a vascular plexus or the spinal nerves via the gray rami communicantes. The largest portion of lumbar sympathetic ganglia is located in the area of the second and third lumbar vertebrae. Therefore, a single-level block along the lower third of L2 or the upper third of L3 is usually sufficient as long as there is adequate medication spread. This chapter describes an injection at the L3 level.

Keywords

block, CRPS, fluoroscopy, RSD, Sympathetic

Note: Please see pages ii , iii for a list of anatomic terms/abbreviations used throughout this book.

Sympathetic nerve blocks are used to help with the diagnosis and treatment of sympathetically maintained pain. The lumbar sympathetic chain typically overlies the anterolateral aspect of the first through fourth lumbar vertebrae. The axons of the lumbar sympathetic preganglionic neurons exit the spinal cord through the ventral roots of the first four lumbar spinal nerves and send fibers through the white rami communicantes to the corresponding lumbar sympathetic ganglia. Postganglionic fibers then exit the chain to join a vascular plexus or the spinal nerves via the gray rami communicantes. The largest portion of lumbar sympathetic ganglia is located in the area of the second and third lumbar vertebrae. Therefore, a single-level block along the lower third of L2 or the upper third of L3 is usually sufficient as long as there is adequate medication spread. This chapter describes an injection at the L3 level.

A successful response to lumbar sympathetic nerve blocks includes an increase in temperature of at least 2°C, vasodilation, and a decrease in pain on the injected side’s lower limb. The diagnostic yield is greatly improved with therapy scheduled immediately after the procedure for a functional reassessment and more aggressive treatment.

Trajectory View

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Confirm the level with the anteroposterior view.
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Tilt the fluoroscope’s image intensifier cephalad or caudad ( Fig. 16.1 ) .

Fig. 16.1

A, Fluoroscopic image of a trajectory view with the needle in position at the superior portion of the L3 vertebral body. B, Radiopaque structures, trajectory view. C, Radiolucent structures, trajectory view.
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The lumbar sympathetic chain overlies the anterolateral aspect of the first through fourth lumbar vertebrae.
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Line up the superior vertebral end plate of L3.
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Oblique the fluoroscope ipsilaterally until the tip of the transverse process is in line with the anterior aspect of the vertebral body.
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The target needle destination is at the inferior portion of the L2 vertebral body or the superior portion of the L3 vertebral body (shown).
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Aim toward the anterior aspect of the vertebral body.
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Place the needle parallel to the fluoroscopic beam.