the purpose of accessing the lateral recess in cases of foraminal stenosis and lateral
recess stenosis. Stenosis or narrowing of the point where the nerve leaves the spine can
occur due to ligaments, bone, disc, blood vessels, scar tissue, or combinations of all
which ultimately have the effect of squeezing the nerve root causing irritation. Using
traditional needle block approaches, the patients may fail to receive relief because the
medication cannot get into the spine when the stenosis is moderate to severe. Most of
the medication flows out away from the spine and away from the problem area which is
causing the pain. Because it is dangerous to place a sharp needle into the area where the
nerve exits for fear of pithing the nerve and causing more damage, use of a blunt needle
with a curved tip is employed. The blunt needle tracks along the nerve root to reach the
lateral recess without injuring the nerve via sharp tip penetration of the nerve. The blunt
needle often permits advancing the tip all the way into the spinal canal with the ability to
direct the needle to the front, back, side, or middle of the spinal canal. This directionality
while using a stiff needle permits breaking through scar tissue and other obstructing
structures while advancing the tip directly to the area of the pathology. Once the
pathology is reached, neurography (injection of contrast material directly onto the nerve
root) is performed yielding more information about the tightness of the stenosis area at
the medial part of the foramen (lateral recess). Because the medication is delivered
through the side of the special needle instead of the end, there is no danger of injecting
the medication directly into the nerve, causing more damage to the nerve.
EXPERIENCE WITH LATERAL RECESS BLOCKS:
Having performed more than 1500 of these blocks as of late 2004, I am impressed by the
safety of the block and the long lasting nature of the blocks. Steroids are delivered
directly onto the area of pathology.
COMPLICATIONS OF THE BLOCK:
5 dural punctures into the spinal fluid have occurred during the past 4 years, none of
which required a blood patch and none of which caused any nerve injury, meningitis, or
other potential spinal problems. There have been no infections. There is a finite
incidence of lacerating blood vessels in the foramen, but this uncommon. The laceration
is detected prior to injection of steroid by performing a neurogram which can reveal
vascular uptake in the case of an aberrantly placed needle. Potential complications
(which I have not witnessed) include protracted bleeding, nerve injury, infection, spinal
cord injury, development of a hematoma of the muscle, meningitis, etc. There are
occasional patients who do not derive relief from the procedure and require a different
pain approach.
SUCCESS RATE:
Somewhat better than the traditional transforaminal steroid injections.
ALTERNATIVES: Transforaminal epidural steroid injection, caudal ESI, interlaminar ESI.
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