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Spine Interventions:
Different Goals
Similar Techniques
eEdE-228
Sepand Salehian
Victor Lopez
James Fernandez
Justin Tran
Lon Hoang
Jonathan Cross
Neuroradiology Fellows at:
T h e au th o r s h ave no f ina nc ia l d is c lo s u r es .
Lumbar Puncture
Intrathecal Sampling
Lumbar Puncture:
Patient Selection
• Indications: meningitis, cytology, pseudotumor cerebri, etc.
• Risks include bleeding, infection, pain, post-LP headache,
and rarely subdural hemorrhage.
• Anti-coagulant medication should be held
• Labs: platelets and PT/INR
• Patient must be able to lie prone without difficulty
• Patient must be able to assume a lateral decubitus position if
intrathecal pressure measurements are necessary
• Other methods are available if patient cannot rotate to a lateral
decubitus position
1
Lumbar puncture:
Procedure
• Needle Selection/Equipment
• 22g spinal needle, easier and
faster CSF collection than 25g
• Quincke (A) -- beveled tip, easy
skin penetration, easy to steer
• Whitacre (B) – non-cutting needle,
theoretical lower risk of CSF leak
• 3.5 inches (9 cm) sufficient for most
patients; 5 inches (13 cm) required
for obese patients
• Standard lumbar puncture kit
Fluoroscopic image demonstrates proper
positioning of 22g spinal needle through the right
interlaminar space
2
Lumbar Puncture:
Technique
• Technique
• Interlaminar space at L1-L2 or below, with patient prone, or slightly
oblique. Oblique positioning opens the interlaminar space.
• CSF Collection
• Typically 3-4 cc in each tube, depending on orders. Cytology requires
more fluid volume; larger volumes reduce false negatives
• Opening pressure
• Measure in left lateral decubitus if possible
• Alternatively, in the prone position, add length of needle to pressure
measurement with manometer at level of needle hub.
• Studies have demonstrated the accuracy of this technique, which merely
overestimate by ~2-3 cm H20
• In patients who cannot rotate, this metric may be used to the operator’s
advantage
• Replace the stylet prior to removal of the needle to reduce the chance
of CSF leak and to reduce risk of possible nerve root injury
• Pitfalls
• Osteoporotic bone – may require formal radiographic spot images for
needle guidance
• Excessive lumbar lordosis – needle may inadvertently contact upper or
lower lamina
• Can increase lumbar flexion by placing pillow under abdomen
• Post-Procedure
• Lie flat on back for 1 hour then discharge
3
Myelograms
Intrathecal Injections
Myelography vs MRI
Myelography: Indications
• Evaluation of local anatomic
topography which may serve to
contact, displace, or impinge the
thecal sac and/or thecal sac contents
(i.e., nerve roots, cord, etc.)
• Offers dynamic and functional
•
• Degenerative causes
• Disk disease
• Vertebral bodies—endplates
• Facets
• Ligamentum flavum
•
•
• Abnormal vessels (Spinal AVM, spinal
dural AVF)
• Arachnoid cysts
• Arachnoiditis
• Perineural cysts
•
evaluation of the CSF space as
compared to MRI
Allows for opening pressure
measurements and collection of CSF, if
indicated
Superior osseous detail as compared
to MRI
Useful in post-operative spine, where
hardware may result in artifact on MRI
MRI is superior for evaluation of
intramedullary or extramedullary
lesions
4
Myelography:
Myelography:
Patient selection and pre-procedure workup
Technique
• Pre-medication for patients with contrast
allergy
• Certain medications reduce the seizure
threshold and should be discontinued
prior to procedure: phenothiazines, MAO
inhibitors, Flexeril, Demoral,
Antidepressants, Antipsychotics,
Amphetamines
• Risks
• Approach and access is identical to
lumbar puncture
• 22g-26g needles
• Decreased chance of post-procedure
headache with smaller bore needles
• Contrast
• Nonionic contrast should be used, as ionic
contrast may result in potentially fatal
neurotoxicity
• Ascending tonic clonic seizure syndrome with
• Fever/infection
ionic contrast
• Positional headache and CSF leak requiring
autologous blood patch
• Seizure
• Headache due to irritation caused by
contrast
• 15 mL of Isovue M200 sufficient for whole
spine
•
Attachment of contrast syringe/tubing to
the needle done in “wet-to-wet” fashion
to avoid air bubbles
• Test injection of 1-2 mL contrast under
fluoroscopy to demonstrate free flow of
contrast in the subarachnoid space
•
Exclude subdural or epidural injection
5
Myelography:
Subdural injection
CSF block
CSF block indicates inability of
intrathecal contrast to migrate further
due to local extrinsic factors.
Consider a lateral decubitus position
to potentially aid further migration of
contrast.
If a subdural injection is
suspected, replace the
stylet and reposition the
needle
A) Fluoroscopic image
demonstrates a globular
collection of contrast
signifying a subdural
injection.
AV fistula
B) Abrupt tapering of
contrast column
indicates CSF block due
to extrinsic factors.
C) CT myelography demonstrates a
serpiginous filling defect in the thecal sac
consistent with a dilated venous structure
in a patient later determined to have a
dural AVF.
6
Myelography:
CT evaluation
•
Roll patient 360 degrees 2-3 times before placing patient onto CT scanner to ensure
adequate distribution of contrast
• Data is acquired at 0.5-0.625 mm and multiplanar reconstructions at 2 mm axial,
sagittal, and coronal planes with both bone and soft tissue algorithms
• Post myelography care similar to lumbar puncture
•
•
•
Lie flat for 1 hour
Hydration
Rarely, contrast may irritate the meninges, but this typically resolves on its own
CT myelography
7
Fluoroscopic Guided Intrathecal Injection
Indications
• Intrathecal injection of
Risks
• IT Chemotherapy
• Risks associated with
chemotherapy
medication– bone marrow
suppression, nausea/vomiting,
pulmonary toxicity, renal
toxicity, seizures
• Some chemotherapeutic
agents, such as methotrexate,
can be toxic to the skin should
direct contact occur
• Therapeutic: leptomeningeal
involvement/meningitis
• Prophylactic:
leukemia/lymphoma with high
predilection for CNS
involvement
• Intrathecal baclofen injection as
• Baclofen
• Hypotonia, headache,
nausea/vomiting, seizures,
respiratory depression, urinary
frequency or retention
trial for baclofen pump to
alleviate spasticity
•
•
•
•
CSF leak
Bleeding
Infection
Pain
8
Fluoroscopic Guided Intrathecal Injection
Technique: IT Chemo
Technique: IT Baclofen (trial)
• Similar approach as a lumbar puncture with
• Note: Trial is done only when there is an
•
•
•
•
patient prone
Upon entering the thecal sac, tubing
attached to the chemotherapy syringe is
connected to the needle
Chemotherapeutic agent injected slowly
over 2 minutes
Small volume of air or autologous CSF is
administered to inject remaining medication
beyond the connector tubing through the
needle
Tubing/syringe combination detached, and
the inner stylet of the needle quickly
replaced before removing the needle
completely so as to avoid backflow of
chemotherapeutic agent onto the skin
understanding that patient will receive a
baclofen pump implant if baclofen trial is
successful
• Standard dose of 50 mcg/1mL administered;
and this can be titrated upward to 100
mcg/2mL if further testing is required
• Patient’s response monitored for an 8-hour
period following the procedure
•
To ensure that baclofen will ablate problematic spasticity
• Trial typically more potent than actual titrated pump
apparatus
• Ashworth scores; Spasm Frequence Scale; and Visual
Analogue Scales are measured pre-test and post-test at
½ hrs, 1, 2, 4, and 6 hours post injection
•
A positive response to an IT baclofen test is defined as 2
point drop on the Ashworth scoring system
9
Lumbar Drains
Lumbar Drains:
Introduction
• Often performed with the assistance of neurosurgery after failed
placement at bedside
• Indications:
• Iatrogenic CSF leak
• Post-operative iatrogenic injury to thecal sac resulting in CSF leak
• Treatment of shunt infections
• Improvement of spinal cord perfusion before or after thoraco-abdominal
aortic aneurysm repair
• Concern for cord ischemia
• Theoretical goal is to relieve pressure and enhance arterial perfusion to cord
• Evaluation of normal pressure hydrocephalus
• Reduction of ICP
• Equipment – Standard lumbar drain kit
• 14g Tuohy needle with a cutting bevel and curved end
• 16g kink-resistant silicone drainage catheter and hydrophilic guidewire
10
Lumbar Drains:
Technique
• Interlaminar space at L2-L3 or below, with the
patient prone or slightly oblique (depending on
location of conus medullaris)
• Image intensifier is positioned to allow for a
cranially angled entry, typically around 40-45
degrees
• If performed on a fluoroscopy table, skin entry
site will be approximately one vertebral body
below the target interlaminar space
• Cranial angulation allows for easier insertion
of the catheter and less kinking
• Once CSF is returned from Tuohy needle and
access into the subarachnoid space is
confirmed, neurosurgery proceeds with
catheter insertion; and connects to drainage
bag apparatus
• The procedure is typically a highly
collaborative endeavor with neurosurgery
Sagittal pictorial of lumbar spine demonstrating 14
gauge needle advanced into the thecal compartment
via a L2-3 interlaminar approach.
11
Lumbar Drains:
Technique
Lateral fluoroscopic view of lumbar spine
demonstrating 14-gauge needle advanced into the
thecal compartment via a L3-4 interlaminar approach.
This particular patient was s/p transphenoidal surgery
and had incurred a CSF leak. Neurosurgery
requested that patient not remain in prone position for
an extended period of time in order to avoid
unnecessary CSF leakage; highlighting the
collaborative nature of the procedure
12
Epidural Injections
Epidural Injection
Introduction
Equipment
• Therapeutic procedure performed in
• Fluoroscopy exam table with rotating C-arm
fluoroscopy suite
• Most common clinical indications:
• Epidural blood patch
•
•
Post dural puncture headache
Spontaneous intracranial hypotension
• Epidural steroid injection
•
Symptomatic degenerative disease, refractory to
conservative treatment options
• Lidocaine, 25g 1.5-inch needle
• 22g Quincke spinal needle
• Lymphangiography connector tubing
• Contrast – Isovue-M200
• Sterile 5 mL syringes
• Can be performed at any level of the spine,
but most often lumbar
13
Epidural Injection - Technique
• Patient positioned prone on exam table
•
Standard prep and drape of the skin surface, site marking, and
application of local anesthesia
• Fluoroscopy views
• Initial AP view should be used to visualize
anatomy and confirm presence of normal
lumbar segmentation
• 15 degree RAO projection will best
visualize the apex of the interlaminar
space
• The opposite 20-35 degrees LAO
projection should be saved as the 2nd
detector position to best visualize the
lamina en face
RAO projection demonstrating the L2-3
interlaminar space. The apex of the
interlaminar space is well seen on this image.
The needle is positioned parallel to the x-ray
beam over this space
14
Epidural Injection - Technique
Needle placement
• Spinal needle should be parallel to
•
•
•
•
xray beam directed toward superior
interlaminar space in the first RAO
projection
Advance approximately 2 cm into the
soft tissues
In the LAO projection, needle tip can
be safely advanced until the tip is just
inferior to the lamina. Needle stylet
should be removed and small 3 mL
syringe with connector tubing should
be connected, with air gap removed
Small amount of contrast can be
injected to confirm position outside the
spinal canal
Needle should be advanced slowly
under continuous fluoroscopy with
slight forward pressure on the syringe
applied
Needle placement (cont.)
• While the needle tip is within the
ligamentum flavum, there will be
significant resistance to contrast
injection
• As needle passes into epidural space,
there will be loss of resistance and
contrast pooling around the needle tip
• Ensure that contrast remains stagnant
in the epidural space by reimaging
with fluoroscopy after a few seconds
delay
• Syringe can be detached from
connector tubing when proper needle
position is confirmed
15
1) Needle tip is placed just
underneath left L2 lamina, as
viewed en face from 25-30
degree LAO.
2) Small amount of contrast test
injection is performed outside
spinal canal. Needle is then
advanced into ligamentum flavum,
where contrast injection is not
possible.
3) There is loss of resistance as
the needle passes through
ligament.
Injected
contrast
pools at the needle tip. Recheck
after few seconds delay to
confirm epidural, rather than
intrathecal placement.
16
Epidural Blood Patch
Technique
Risks
• Procedure assistant should slowly aspirate blood
•
from sterilized peripheral IV
• Inject autologous blood to the epidural space
• The patient should be informed that a pressure
•
•
•
•
sensation in the lower back, that may radiate to the
ventral abdomen, buttocks or legs can be expected
Inject up to 5 mL of blood and reassess the patient
at each interval
Volume of injected blood should be titrated to
patient’s tolerance
Up to 30 mL can be administered in a single
treatment, though a target of 20 mL is used at our
institution for first treatment
Volume can be increased if patient requires repeat
treatment
• Needle can be removed after completion of
blood patch injection
• Routine observation for 1 hour in a monitored
recovery area
•
•
Bed rest with bed flat, or slight Trendelenberg position is
recommended during recovery period
Outpatients can be discharged home after the short recovery
time
•
General procedure risks related to needle
placement:
• Infection, including meningitis
• Hemorrhage
• Pain
• Unintended dural puncture, which will
often require needle removal and access
at a different interlaminar level
• Patient should be informed that in select
cases, they may experience worsening
of headache related to rebound
intracranial hypertension
Other symptoms post-procedure:
• Nausea
• Radicular pain/paresthesia
• Dizziness
17
Epidural Blood Patch
Sagittal pictorial demonstrates an interlaminar approach epidural blood patch. Red column of autologous blood is demonstrated lining the epidural space.
18
Epidural Steroid Injection
Technique:
Risks:
• Needle placement is identical to technique
•
applied for an epidural blood patch injection
• Prior imaging should be reviewed to target level
above that possessing the greatest
degenerative disease or neural impingement
• After the needle position is confirmed in the
epidural space, total of 2 mL betamethasone
(6mg/mL) can be administered and followed by
2 mL injection of preservative-free 0.5-1%
lidocaine
•
It is critical to avoid advancing needle into the
subarachnoid space, causing chemical
arachnoiditis due to steroid injection or spinal
anesthesia related to lidocaine
If unintended dural puncture occurs, the needle
should be removed with stylet in place and a
new site should be chosen at a different
interlaminar space on the contralateral side
19
Epidural Steroid Injection
Sagittal view pictorial demonstrates an interlaminar approach epidural steroid injection. Grey steroid injection is seen lining the
epidural space and partially covering the affected nerve.
20
Transforaminal Epidural Steroid Injection
• Introduction
• Alternative approach for therapeutic steroid
injection can be used for selective treatment of a
specific symptomatic nerve root
• Prior MRI or CT should be reviewed to confirm
impingement of the target nerve root
• Fluoroscopy views:
• Initial AP view to survey anatomy and confirm
trajectory
• C-arm should be rotated to an oblique projection
where the “scotty dog” appearance of posterior
elements is well visualized
• The site of skin entry should be marked just
inferior to the pedicle above targeted neural
foramen
• Needle should be parallel to x-ray beam on the
oblique projection; then C-arm can be rotated to
direct AP for further needle advancement until
needle tip is just below pedicle
• Small injection of contrast should confirm that the
needle tip is not within a vascular structure or
thecal sac
• Ideally, the small amount of injected contrast
should be visualized flowing underneath the
pedicle and into the epidural space
Proper projection for localization of the left
L5-S1 neural foramen, with RAO and slight
cranial angulation of the xray beam. Needle
placement should be targeted immediately
inferior to the ipsilateral L5 pedicle.
21
Transforaminal Injection
Transforaminal Epidural Steroid Injection
• Alternatively, if performing a
selective nerve root block, the
needle can be positioned distal to
the dorsal nerve root ganglion
(slightly more lateral) in the neural
foramen, with contrast seen only
surrounding a single nerve root
sleeve
AP projection demonstrates needle tip positioned
inferior to the pedicle, with injected contrast flowing
medial to the pedicle into the epidural space of the
spinal canal
22
Disc Interrogation:
Disc Aspiration/Biopsy
Provocative Discography
Posterolateral approach (lumbar)
Anterolateral approach (cervical)
Disc Aspiration
Introduction
Equipment
Recovery and Risks
•
•
• Lay flat for 1 hour and no heavy lifting
At our institution, the most common indication
for a disc aspiration is suspicion of infection
(discitis/osteomyelitis).
•
•
Isolates/cultures requested for targeted antibiotic therapy
Infective discitis has an incidence of 0.4-2.4
per 100,000 each year in the western world
with a bimodal age distribution (childhood and
6th decade). The lumbar spine is most
commonly affected (up to 60%), followed
by thoracic and cervical spine.
Biplane Fluoroscopy
system or CT
• Local Anesthetic
• Sterilizing solution
• Needle kit
or strenuous activity for 24 hours
• Risks:
• Risks associated with the procedure are
similar to any biopsy including, damage
to any of the surrounding structures
including the spinal cord, and lack of a
final diagnosis requiring a repeat
aspiration
• Fever, severe pain, neuropathic pain,
and bleeding
23
Disc Aspiration (Lumbar) – Posterolateral Technique
Technique
•
Prep and drape in usual sterile fashion
•
Image intensifier is positioned such that the
endplates are in profile and the superior
articular process projects over the midportion of the intervertebral disc. The
anterior margin of the superior articular
process serves as a landmark for Chiba
needle entry
•
18-22g Chiba needle is advanced via the
far lateral approach to the outer annulus of
the disc. The inner stylet is removed and
aspiration is performed from this location. If
there is no fluid return, the stylet can be
replaced and further advanced (with
confirmation of position on AP imaging)
and aspiration reattempted.
•
The stylet is replaced and the introducer
needle is then removed.
Example: L3-4 discitis
T1 weighted fat saturated contrast
enhanced sagittal image demonstrating
post contrast enhancement and irregularity
of the L3-4 disc space and adjacent
endplates
The II is positioned so that the facet bisects
the intervertebral disc space. The needle is
advanced parallel to the x-ray beam, anterior
to the facet.
AP view should be obtained to confirm
needle position. Needle is then carefully
advanced to the desired location within the
disc.
24
CT guided C-spine disc/body aspiration:
Case example of a cervical CT guided aspiration via an anterolateral approach
33 year old IV drug user presents with fever and neck pain
T2 weighted sagittal image:
There is focal kyphosis of the C-spine at C5-6,
with associated anterior loss of height of the C5
and C6 vertebral bodies. There is
accompanying significant edema at C5 and C6,
and high signal intensity in the disc.
T1 sagittal image:
There is hypointensity in the C5 and
C6 vertebral bodies
T1 post-contrast sagittal image:
There is enhancement throughout C5,
C6, C5-6 disc, and along the prevertebral
soft tissues
24
Percutaneous anterolateral cervical spine approach
• Peri-operative
• Consent and labs obtained
• General anesthesia
• CT guided anterolateral cervical technique
• Via manual compression, the carotid artery and internal
jugular vein are displaced inferiorly relative to the operator
(posteriorly relative to patient). This creates a soft tissue
plane devoid of any critical structures and provides
maximal displacement of such structures to avoid
untoward complications. The rebounding pulse of the
carotid artery is felt on the palmar aspect of the operator’s
digits, indicating that the vessel will not be in the trajectory
of biopsy needle
• 22g spinal needle is positioned on the skin surface just 1-2
mm above the dorsal aspect of the operator’s digits.
• 22g needle is advanced beyond the medial boundary of
the carotid space (per a distance determined to be safe by
pre-operative imaging), beyond the circum-periphery of the
vascular structures
• Sequential CT images are obtained as needle is advanced
to ensure safe guidance to target site. Hypopharynx
(airway) and laryngeal structures are avoided
• Sample aspirations are obtained
• Similar approach may be used for cervical
CT guided aspiration at C5-6 level:
Sequential CT images demonstrate progressive
advancement of spinal needle until target is reached at the
C5-6 disc space
vertebroplasty targeting the mid-body.
25
Percutaneous anterolateral cervical spine approach
Graphical pictorial depicts the anterolateral approach to the cervical disc
aspiration.
CT guided aspiration at C5-6 level:
Sequential CT images demonstrate progressive
advancement of spinal needle until target is reached at the
C5-6 disc space
26
Provocative discography - Introduction
• Used as an adjunct to identify cause of back pain due to an
unsuspected annular fissure
• Useful in cases of clinical discordance between chronic pain and
lack of imaging findings. Enables identification of the true
symptomatic level in the setting of multiple disc herniations
• Indications from North American Spine Society
• ALL must be present
• If surgical management is a viable option
• Pain is not responsive to conservative treatment measures
• Pain persists for an extended period of time
• No evidence of contraindications such as severe spinal stenosis resulting in intraspinal
obstruction, infection or predominantly psychogenic pain
• At least ONE of the following is present
• A high index of suspicion for discogenic pain where the pain is severe enough to consider
surgical intervention
• Failed back surgery
27
Provocative discography - Procedure
• Prep and drape in usual sterile
fashion
• Image intensifier is positioned such
that the endplates are in profile and
the superior articular process
projects over the mid-portion of the
intervertebral disc
• The anterior margin of the superior
articular process serves as a
landmark for 22g Chiba needle
entry
• Typically three levels are studied; at
least one “normal” level serves as
an internal control
• Place all needles prior to contrast
injection and confirm correct needle
tip position with AP and lateral views
L5-S1 right oblique approach. Note the triangular window for entry
formed by the superior articular process medially, iliac crest laterally,
and L5 inferior endplate superiorly
28
Provocative discography - Procedure
•
•
•
•
•
•
Patient is blinded to level of injection
Controlled hand injection of 1-2 mL of
Omnipaque 240
Nurse observes the patient response with direct
questioning
Identify extension of contrast beyond the
confines of the nucleus pulposus
Injection may elicit pain, characterized as
concordant or discordant to baseline pain profile
Post-discography CT
Normal L4-L5 nucleogram. The patient did not experience pain at any point during injection
L5-S1 nucleogram showing diffuse broadening of contrast consistent with diffuse internal fissuring.
29
Provocative discography - CT
Axial and sagittal CT lumbar discogram
(axial slice at the L2-3 level):
At L2-3: Anterior radial fissure with
associated extravasation anteriorly, with a
circumannular fissure.
At L3-4: (Anterior fissure not well seen)
At L4-5: Diffuse internal fissuring
Axial and sagittal CT lumbar discogram
(axial slice at the L4-5 level):
At L3-4: Normal appearing nucleogram.
At L4-5: Normal appearing nucleogram
At L5-S1: Diffuse internal fissuring and diffuse
internal derangement
Of note: In this case, there was sacralization
of the L5 vertebral body. As this represents a
non-mobile segment, it was unnecessary to
include L5-S1 as part of provocative
discographic study.
30
Disc Sampling
Disc sampling (aspiration or provocative discography): pictorial demonstrates the similar
posterolateral technique employed by both procedures.
31
Vertebral Body Biopsy
Radiofrequency Ablation
Vertebral Augmentation
The Vertebral Body Biopsy
Introduction
Equipment
•
•
Image guided spinal bone biopsies are
conducted for histopathological diagnosis of
indeterminate sclerotic/lytic lesions, often
found incidentally on MR/CT imaging
• Spinal biopsies are either performed on a
biplane fluoroscopy system in an
interventional suite or on a CT scanner (CT
guidance is usually preferred for cervical,
upper thoracic, and sacral lesions as
overlying soft tissues may result in difficulty
localizing the lesion using fluoroscopy in
these regions)
•
•
•
•
Biplane fluoroscopy/CT
Sterilizing solution
Local Anesthetic
Mallet
Osteo-Site Murphy Coaxial Bone
Biopsy Needle Set (11G coaxial with
an inner 14G biopsy needle or
13G/16G set, 10 or 15cm length)
Recovery
•
2 hour observation
• Patient lay flat for 1 hour
• No heavy lifting or strenuous
activity for 24 hours
Risks
•
•
•
•
•
Infection
Pain
Bleeding (i.e. epidural hematoma)
Damage to any of the surrounding
structures including the spinal cord
Lack of a final diagnosis requiring a
repeat biopsy
32
The Vertebral Body Biopsy:
Technique
•
•
•
Skin overlying the desired vertebra is prepped and draped
in usual sterile fashion with the patient prone on the
fluoroscopy table.
Skin entry site overlying the desired pedicle is marked once
the image intensifier is in position (pedicle is viewed
parallel to the x-ray beam).
Local lidocaine anesthetic is administered to the
subcutaneous tissues and periosteum overlying the pedicle
and a small skin incision is made.
• Biplane fluoroscopy
• Superior and inferior endplates are lined up on AP
and lateral view perfectly
• Bilateral pedicles and ribs are aligned and
perfectly superimposed on lateral view, with
minimal redundant shadows
• Pedicles are well visualized
• If pedicles are not adequately visualized: consider
aborting procedure; consider CT guidance
measures; consider parapedicular approach
• Using a transpedicular approach, a 11-13 gauge
Osteo-site vertebral biopsy introducer needle is
situated upon the pedicle
•
•
•
•
•
•
Obtain purchase in pedicle (tactile texture differences between
osteoporotic vs. neoplastic vs. osteosclerotic bone)
Adjust hand to tripod position for superior control and maneuverability
Needle trajectory should be parallel to x-ray beam (such that needle
appears as a dot)
The introducer needle is carefully advanced through the pedicle by
continuous manual pressure or with a mallet
The needle tip is positioned proximal to the lesion under fluoroscopic
guidance.
Using co-axial technique: the inner stylet is removed and biopsy needle
is advanced
• This is done with a twisting motion under pressure, or small mallet
may be used to gently tap if the lesion is sclerotic.
•
The biopsy needle is then removed with application of gentle
aspiration. The specimen is placed on a slide and given to onsite cytopathology for immediate review.
• The inner stylet is then replaced and the introducer needle is
removed under fluoroscopic guidance with direct manual
compression applied.
• Once hemostasis is achieved and there are no immediate
complications, the patient can be transferred to the PACU by
anesthesia.
33
L1 Vertebral Body Biopsy: Example Case of L1 lesion
T1 weighted fat saturated
contrast enhanced sagittal and
axial images demonstrate an
enhancing lesion in the L1
vertebral body.
Pedicle is oriented in a trajectory
parallel to the x-ray beam; as is
the biopsy needle. The pedicles
above and below the target
vertebral body can be used as
landmarks to orient the operator.
The medial margin of the pedicle
must be respected.
Confirm needle placement on both AP and lateral projections immediately before and during
the biopsies
34
Image-guided Radiofrequency Ablation of Spinal Tumors
Technique, Indications, Risks:
• Employs radiofrequency as a source of thermal energy
• High frequency alternating current is passed through needle, which causes
local frictional heating and tissue necrosis
• Ellipsoid ablation volume at marker = 30 x 20 mm @ 50 C
• Typically done after vertebral body biopsy in patients with osseous
metastatic disease confirmed by on-site cytopathology.
• The setup, approach, and preparation are identical to vertebral
body biopsy.
•
•
The identical outer cannula used for the biopsy/vertebroplasty is used first
to advance the RF probe directly into the lesion
Ablation occurs under real time imaging guidance to ensure steadfast
location of RF ablation needle tip/marker
•
•
Equipment:
• MetaSTAR Generator
• SpineSTAR ablation instrument
• AE cable
• Hand Switch cable
Risk of thermal ablation of neural tissue needs to be minimized
If pathologic fracturing is present, then vertebral augmentation follows RF
ablation
•
Necrotic tissue may theoretically improve cement distribution
• Indications include:
• Radio/chemotherapy-resistant tumors
• Patients who have received maximum doses of radiation
• Persistent pain
•
•
Palliative endeavor
Patients at risk of myelosuppression
• Risks
• Heating of tissue to 45 C is cytotoxic to spinal cord and peripheral nerves
•
•
•
Care should be taken in vertebral lesions when tumor invades posterior cortex,
as there is a higher risk of thermal damage to nerves and cord
High risk lesion is defined as a tumor within 1 cm of a neural structure
Radicular pain
35
Vertebral Augmentation
Osteoporosis
• World Health Organization (WHO) defines osteoporosis as a bone mineral density at the
hip or lumbar spine of greater 2.5 standard deviations below the young normal adult
reference population
• Aging population is increasing in size
• 55% of Americans over the Age of 50 suffer from osteopenia or osteoporosis
• Women make up 80% of the population affected with osteoporosis
• Expected to affect 14 million people by 2020
• Economic burden: costs the United States 20.3 billion dollars; actual cost likely higher as
it is difficult to account for the indirect costs of disability, time off work, pain, diminished
mobility, insomnia, and depression
• Hallmark of osteoporosis is lack of ultrastructural integrity within bone architecture
• Compromised bone strength
• Low bone mass
• Disruption of bone architecture
• Fractures of fragility or insufficiency fractures
• May result from standing height
• Common sites include the vertebra, hip, and wrist
• Vertebral compression fractures quite simply interferes with the activities of daily living
36
Vertebral Augmentation:
Osteoporotic compression fractures
• Substantial acute and chronic pain—substantial
morbidity
• Severe thoracic kyphosis due to a compression fracture can
cause up to a 10% diminished pulmonary forced vital capacity
• Increased kyphosis of abdominal cavity can also result in
reduced satiety
• 5-year survival of a patient who sustains a compression
fracture is lower than a similar patient with a hip fracture
• Mainstay of conservative management: oral narcotic
analgesia, NSAIDS, bed rest, orthosis, physical
therapy/exercise, and medical treatment of osteoporosis
• Spinal orthoses reduce pain by reducing motion, decreasing
postural flexion, and providing axial support
• Exercise promotes muscle growth which in turn provides
columnar support to the spine
• Basics of imaging diagnosis
• Lateral and AP of the spine to detect degree of height loss
• MRI can differentiate between acute, subacute, or healed
osteoporotic compression fractures (edema on T2 weighted
imaging)
• CT would allow for evaluation of the integrity of the posterior wall
of the vertebral body
CT L Spine sagittal view: There is a L2
compression fracture deformity with mild loss of
height. There is no associated retropulsion.
Posterior wall is intact.
37
Treatment for compression fractures:
Vertebroplasty, Kyphoplasty, Vertebral Augmentation
Vertebroplasty
Kyphoplasty
Vertebral Augmentation
Once the needle is advanced
to the middle of the vertebral
body, PMMA is directly
injected. No other maneuver
is entertained.
Theoretical intent is height
restoration of vertebral body
height by directing a balloon
into the mid-body to restore
height in a craniocaudad
dimension; then injecting
PMMA.
Vertebral augmentation
implies the creation of cavity
prior to the delivery of
PMMA. Certain kits provide
a needle osteotome to create
an excavation in the mid
vertebral body, after which
PMMA is injected.
38
PMMA:
Postulated Biomechanisms of Action
• Vertebroplasty, kyphoplasty, and vertebral augmentation all have a similar underlying basis,
approach, and goal; with slightly different technical aspects pertaining to the delivery of the
PMMA cement
• Vertebral augmentation implies the creation of a cavity by way of an osteotome device, and then depositing
cement
• Kyphoplasty implies the attempt at height restoration by using a balloon to expand the fracture site, and then
depositing cement
• Vertebroplasty implies reaching the target fracture line, then depositing the cement
• PMMA cement confers stability to the vertebral body fracture line, thereby reducing friction
and internal dynamic instability which creates the sensation of pain
• Initially, polymethylmethacrylate (PMMA) was implemented to treat aggressive variants of
vertebral hemangiomas
• Thereafter, its use evolved as a means to treat painful metastatic lesions to the spine
• Explanations and potential biomechanisms of action
• Thermal necrosis; chemotoxicity upon intraosseous pain receptors
• Cement monomer itself may be a neurotoxic compound disabling pain receptors locally
• Polymerization reaction of PMMA is exothermic reaching temperatures of up to 122 C
• Clinically efficacious in reducing pain
• Controversy surrounds whether or not height restoration in kyphoplasty occurs
39
Indications/Patient selection
• Characterization of pain
• Pain is at the level of the fracture; and is exacerbated with bending, prolonged standing or
sitting, and improves with rest
• Focal tenderness over the site of the fractured vertebrae on physical examination
• Timing of intervention is poorly defined: treatment may be pursued in as early as
2-6 days; others wait until patient has failed 2-6 weeks of conservative therapy on
oral/opiate analgesia, and supportive orthosis
• Advocates of early treatment argue that kyphotic deformity results in maldistribution of load on
the spine increasing the risk of future fractures
• Acute or subacute fracture on MRI
• Patient mobility is a very important issue
• If patient is mobile, patients who still have pain after 4-6 weeks are considered candidates
• If patient is non-mobile, patients with pain are offered an earlier percutaneous vertebral
augmentation
• Intervention more like to improve symptomology with the following fractures as
they are less likely to improve with conservative treatment:
•
•
•
•
Thoracolumbar junction (T11-L2)
Osteoporotic burst fractures
Wedge anterior compression fracture > 30 degrees angulation
Continued collapse on follow up imaging
40
Contraindications
• Absolute contraindication
• Active local infection: osteomyelitis, discitis, epidural abscess, fever,
sepsis
• Bleeding diathesis
• Relative contraindications
• Cortical disruption makes cement containment difficult
• Only after careful pre-operative consideration may patient undergo
percutaneous vertebral augmentation
• Posterior wall destruction and/or tumor extension into spinal canal
• Increased risk of neural compression with injection of cement
• Vertebra plana—renders procedures more technically difficult
• Radiculopathy obscures the true nature and origin of the back pain
• Retropulsion; or other sinister epidural pathology that may cause canal
obliteration
• Osteoblastic lesion
• Lack of immediate decompressive surgery capability
41
Vertebral Augmentation: Peri-procedural
Proper pre-procedure imaging:
• CT, MR
• Confirm the spinal level with
patient and room staff
• Prophylactic antibiotics
• IV Ancef
• Tobramycin (powder formintermixed with cement)
• Anesthesia
• Local anesthesia
• Local is injected in the
skin, subcutaneous
tissues, and periosteum
of the vertebra
• Conscious sedation/Moderate
sedation
• General anesthesia
• In cases involving CT guided
needle localization, general
anesthesia will provide
optimum situational control
• Also ideal for multilevel
vertebroplasty
Equipment:
•
Biplane fluoroscopy/CT
•
Mallet
•
StabiliT Kit
•
Hydraulic Master Syringe
Assembly
•
Activation element
•
DFINE introducer
•
Locking delivery canula
•
VertecoR Straightline
Osteotome/midline osteotome
•
StabiliT ER2 bone cement and
saturate mixing system
Risks:
• Transverse process fractures
• Hemorrhage with cortical breeches
• Epidural hematoma
• Infectious osteomyelitis
• Sterility within operating field must
be maintained
• Cement leak
• Can occur in the epidural veins
• Leading to pulmonary
embolism
• Epidural space
• Overflow of PMMA into epidural
space can cause spinal cord
compression
• Neural foramina
• Pain
• Due to injecting at high pressure
• Osseous ischemia
• Inflammatory reaction to PMMA
cement
42
Anatomy
Inferior vena cava
Aorta
Lumbar vein
Basivertebral vein
3D conception of
vertebral anatomy is
important in order to
discriminate local
topography with
internal landmarks.
Note:
1) Medial border of
the pedicle
2) Epidural space
3) Vascular structures
Anterior internal epidural
venous plexus
Transverse
process
Pedicle
Cord
Spinous process
43
Common Approaches
Transpedicular
Parapedicular
• Most common approach
• Pedicle serves as a clear anatomic
landmark
• Respect the medial boundary to avoid
transgressing the epidural space
•Allows operator to pass along lateral to the
pedicle, rather than through it
•Indications: pedicle is too thin; not visualized; or
destroyed by tumor burden rendering it
inaccessible
•Risks: greater risk of paraspinous hematoma;
decreased ability to control post-procedural
bleeding by local tamponade
44
Anatomy and Guidance
Axial and sagittal pictorials of a lumbar vertebral body demonstrating needle position at varying angulations, which
affects height and laterality of distal tip.
The pictorials demonstrate the import of needle positioning and obeying structural landmarks: medial margin of
the pedicle, anterior margin of vertebral body, and endplates.
Red zones: 1) Beyond the anterior margin of the vertebral body rests the aorta/IVC; 2) Medial to the pedicle is the
epidural space/thecal sac; 3) inferior to the pedicle is the neural foramen
45
Vertebral Augmentation Technique
•
•
•
•
Biplane fluoroscopy
• Superior and inferior endplates are lined up on AP and lateral view
perfectly
• Bilateral pedicles and ribs are aligned and perfectly superimposed
on lateral view, with minimal redundant shadows
• Pedicles are adequately visualized
• If pedicles are not adequately visualized, consider aborting
procedure; consider CT guidance measures; consider
parapedicular approach
Local anesthetic/skin incision
Guide 11-13 gauge needle (trocar+canula) into the pedicle or target site
• Transpedicular: Obtain purchase in pedicle (tactile texture
differences between osteoporotic vs. neoplastic vs.
osteosclerotic bone)
• Adjust hand to tripod position for superior control and
maneuverability
• Needle trajectory should be parallel to x-ray beam (such that
needle appears as a dot)
• Use mallet to guide needle through bone
• Advance needle tip to the anterior border of the middle portion
of the vertebral body proper on lateral view
• Remove trocar and co-axially advance the osteotome needle
• Rotate osteotome to cross the midline and create a cavity
into which cement will be posited
Inject PMMA
• Under realtime fluoroscopic guidance, visualize delivery of
PMMA in two planes
• Different admixtures have different hardening times and
operator should be aware of time limitations to administer
cement
• Important to have the PMMA enter through the fracture line
•
•
•
Ending the procedure
• Reinsert the trochar
• Rotate canula several times
• Slowly remove needle
Apply manual pressure to incision site
Post-operative care and monitoring
• Recovery and monitoring for 2-3 hours
• Supine position
• PMMA cement usually hardens to 90% in 1 hour
• Evaluate for neurological and hemodynamic changes
• IF there are any undesirable clinical changes obtain CT or
MRI
• NSAIDS and oral narcotic analgesia initially only if necessary
• Monitor pain level
46
Vertebral Augmentation Technique
C
E
A
B
G
D
F
L3 compression fracture:
A) Pictorial demonstrates importance of establishing an obliquity parallel to the pedicle such that it can be viewed “en face”. B) Utilizing tripod
technique with hand, the 13g introducer needle is positioned over the pedicle; adjusted parallel to the x-ray beam; and advanced with a mallet,
intermittently repositioning as it is directed through the pedicle. C,D) Note the perfect alignment of the superior endplates on both the lateral and the
AP projection; and note the near perfect anatomic alignment of bilateral pedicles on the lateral. Once the 13g needle is positioned through the midbody, the osteotome is inserted co-axially through the canula; rotated ideally to create a cavity which extends through the midline of the vertebral body.
E,F) If a larger cavity is desired, the osteotome can be maneuvered in different ways to excavate other parts of the vertebral body. G) Finally, once a
cavity is established, the osteotome is removed, and the engineered cavity may be filled with PMMA, here seen on the AP view. Ideally, the
introduction of cement is viewed in real-time under fluoroscopic guidance in both AP and lateral projections.
47
Vertebral Augmentation Technique
C
B
E
A
D
L1 compression fracture:
A) STIR sagittal MRI demonstrates acute compression fracture of the L1 vertebral body with edema and retropulsion. B) The endplates, the pedicles,
and the ribs are perfectly aligned by rotating the C-Arm. Fluoroscopic image demonstrates the L1 compression fracture. C, D) After having placed the
13g needle through the pedicle and into the body, the osteotome is positioned and is rotated to cross the midline. E) The lateral view demonstrates
PMMA within the L1 vertebral body. The posterior border of the body is well respected; the anterior margin demonstrates no evidence of leakage.
48
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Acknowledgments:
UTSW Medical Illustrator Department