Algos Techniques
Transcaudal Lateral Recess Block
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The transcaudal lateral recess block was devised to produce a rapid reproducible
injection at the level of the L4-5 or L5-S1 disc or exiting nerves at that level in the case
where traditional approaches have failed. It should be noted this approach is a
non-standard approach and has not been published, therefore I am not advocating its
widespread use. It is used in selective situations which require unorthodox
approaches to the anterior epidural space or lateral epidural space in order to access
the disc or the exiting nerve in the lateral recess. Foraminal stenosis or prominent
transverse foraminal ligaments can produce situations in which contrast egresses from
the traditional infrapedicular approach without any epidural ingress. When repeated
attempts at re-angulation of the needle tip fail to demonstrate a neurogram ingressing
into the epidural space to the level of the target disc as in the first figure, alternative
measures for steroid delivery must be explored. Because the targeted disc herniation
is usually paramedian and compresses the nerve at the level of the herniation, typically
the transforaminal approach used is infrapedicular as shown in the second figure. This
technique relies on diffusion of the steroid along the path of the nerve root to the level
of the disc herniation. Disc compression of the nerve produces numbness but pain is
likely produced by the presence of cytokines and tumor necrosis factor alpha exuding
from the disc onto the nerve root. It is possible these substances cause DRG edema
and the pain is due to DRG edema rather than disc induced inflammation of the nerve
root at the discal level (since the nerve is enveloped in a dural sleeve at the level of a
disc herniation and thereby may be more protected at the disc level). Nevertheless,
the current logic is to use the diffusion along the nerve root to deliver the epidural
steroid to the target disc.
PATIENT SELECTION: Lumbar radicular pain with dermatomal correspondence of
the L4, L5, or S1 nerve root compression. Prior spine surgery within one vertebral
body of the target may render the epidural space full of scar tissue that can cause a
much greater likelihood of a dural tear.
NEEDLE: Blunt needles such as the 20 ga Epimed (shown at left) 203mm length are
preferred (with the introducer 16 ga Angiocath). The extraordinary length of this
needle permits access to the L3-4 level in most patients.
SEDATION: Optional, however most patients prefer it given the advancement of the
needle in the spinal canal can cause occasional twinges of pain.
DESCRIPTION Lateral Recess Block: The needle has two curves placed into the
needle: a tip 20 degree curve and a shaft 20 degree curve. The long shaft curve
serves to permit direction of the needle into the anterior epidural space and lateral
while the short curve permits fine tip placement. The patient is in the prone position
and the skin over the caudal canal and sacrococcygeal ligament is prepped in the
usual fashion. Local anesthesia is injected subcutaneously and on the mid coccyx
angling towards the SC ligament. A 16ga angiocath is introduced direcly in the midline
over the mid coccyx and advanced through the SC ligament and into the caudal canal,
but not further than S3. The needle is removed and replaced with a 20ga 203 mm
blunt needle which is advanced through the angiocath and along the anterior portion of
the caudal canal. During the advancement, keep the needle tip anterior and
simultaneously lateral once the S3 neuroforaminal level is reached. Continue
advancing the needle until it meets the inferior disc. Rotate the needle tip lateral.
Advance the needle to the pedicle at an inferio-medial point on the pedicle itself.
Following a negative aspirate for blood or CSF, perform a live injection neurogram and
if digital subtraction is available, employ it. Alternatively, the disc itself may be
targetedd. Steroid may then be injected into the lateral recess. Alternatively, if the
L5S1 disc is the target, retain the anterior rotation of the tip until that level of the disc
is reached and perform an epidurogram in the lateral epidural space prior to
installation of steroids.
NOTE: NEVER TURN THE NEEDLE TIP MEDIALLY OR EVEN PARTIALLY
MEDIALLY AS TEARING THE DURA DURING ADVANCEMENT IS POSSIBLE>
injection at the level of the L4-5 or L5-S1 disc or exiting nerves at that level in the case
where traditional approaches have failed. It should be noted this approach is a
non-standard approach and has not been published, therefore I am not advocating its
widespread use. It is used in selective situations which require unorthodox
approaches to the anterior epidural space or lateral epidural space in order to access
the disc or the exiting nerve in the lateral recess. Foraminal stenosis or prominent
transverse foraminal ligaments can produce situations in which contrast egresses from
the traditional infrapedicular approach without any epidural ingress. When repeated
attempts at re-angulation of the needle tip fail to demonstrate a neurogram ingressing
into the epidural space to the level of the target disc as in the first figure, alternative
measures for steroid delivery must be explored. Because the targeted disc herniation
is usually paramedian and compresses the nerve at the level of the herniation, typically
the transforaminal approach used is infrapedicular as shown in the second figure. This
technique relies on diffusion of the steroid along the path of the nerve root to the level
of the disc herniation. Disc compression of the nerve produces numbness but pain is
likely produced by the presence of cytokines and tumor necrosis factor alpha exuding
from the disc onto the nerve root. It is possible these substances cause DRG edema
and the pain is due to DRG edema rather than disc induced inflammation of the nerve
root at the discal level (since the nerve is enveloped in a dural sleeve at the level of a
disc herniation and thereby may be more protected at the disc level). Nevertheless,
the current logic is to use the diffusion along the nerve root to deliver the epidural
steroid to the target disc.
PATIENT SELECTION: Lumbar radicular pain with dermatomal correspondence of
the L4, L5, or S1 nerve root compression. Prior spine surgery within one vertebral
body of the target may render the epidural space full of scar tissue that can cause a
much greater likelihood of a dural tear.
NEEDLE: Blunt needles such as the 20 ga Epimed (shown at left) 203mm length are
preferred (with the introducer 16 ga Angiocath). The extraordinary length of this
needle permits access to the L3-4 level in most patients.
SEDATION: Optional, however most patients prefer it given the advancement of the
needle in the spinal canal can cause occasional twinges of pain.
DESCRIPTION Lateral Recess Block: The needle has two curves placed into the
needle: a tip 20 degree curve and a shaft 20 degree curve. The long shaft curve
serves to permit direction of the needle into the anterior epidural space and lateral
while the short curve permits fine tip placement. The patient is in the prone position
and the skin over the caudal canal and sacrococcygeal ligament is prepped in the
usual fashion. Local anesthesia is injected subcutaneously and on the mid coccyx
angling towards the SC ligament. A 16ga angiocath is introduced direcly in the midline
over the mid coccyx and advanced through the SC ligament and into the caudal canal,
but not further than S3. The needle is removed and replaced with a 20ga 203 mm
blunt needle which is advanced through the angiocath and along the anterior portion of
the caudal canal. During the advancement, keep the needle tip anterior and
simultaneously lateral once the S3 neuroforaminal level is reached. Continue
advancing the needle until it meets the inferior disc. Rotate the needle tip lateral.
Advance the needle to the pedicle at an inferio-medial point on the pedicle itself.
Following a negative aspirate for blood or CSF, perform a live injection neurogram and
if digital subtraction is available, employ it. Alternatively, the disc itself may be
targetedd. Steroid may then be injected into the lateral recess. Alternatively, if the
L5S1 disc is the target, retain the anterior rotation of the tip until that level of the disc
is reached and perform an epidurogram in the lateral epidural space prior to
installation of steroids.
NOTE: NEVER TURN THE NEEDLE TIP MEDIALLY OR EVEN PARTIALLY
MEDIALLY AS TEARING THE DURA DURING ADVANCEMENT IS POSSIBLE>
