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Troubleshooting Intrathecal
Therapy Systems
Michael Saulino, MD PhD
MossRehab
Assistant Professor
Thomas Jefferson University
Adjuvant Assistant Professor
Temple University
Intrathecal Delivery Issues
• Pump
–
–
–
–
Battery failure
Empty reservoir
Programming errors
Roller stall
• Catheter
– Kinks, holes, blockages
Programming Issues
• Check for alarms
• Check electronic logs
• Verify drug concentration, daily/ hourly
dosing, alarm volume/date
– Check for dose per day or dose per hour
• Bridge bolus during concentration change
– Compensates for the residual solution in the
pump and catheter
Pump Motor Stall
• Most commonly caused by gear shaft wear
• Incidence between 0.5% and 2.2 % at 7 years
post implant
• More common with older pumps
• Undetectable with pump interrogation with
older pumps
– Need to investigate radiographically
• With new pumps, there is an electronic log of
any motor stall
X-ray SynchroMed EL AP View
Potential Catheter Disruptions
Copyright Ellen Barker Michael Saulino
7
Catheter Micro-fractures
Investigation Techniques
for Catheter Problems
Plain radiography
Catheter dye study
CT myelogram
Nuclear medicine cisternogram
Magnetic resonance imaging
Plain radiography
• AP/lateral thoracic and lumbar spine,
flat plate of abdomen and spot film over
pump site
• Always check your own films
• Advantages: can be done remotely
without technical expertise
• Disadvantages: will probably only pick
up gross breaks and tears, projection
difficulties
Catheter dye study
• Access catheter access port, aspirate
catheter contents/CSF, discard fluid,
inject myelogram dye with real-time
fluoroscopy, reprogram pump to refill
catheter
• DO NOT INJECT DYE IF YOU
CANNOT ASPIRATE CATHETER
CONTENTS
Catheter dye study
• Advantages:
– ? improved sensitivity compared to plain
films
• Disadvantages:
– technical expertise
– can’t inject if you cannot aspirate
– will probably miss small tears
CT myelogram
after side port injection
• Remove 2-3 mls of fluid
• Inject 2-3 mls of isotonic contrast
• Patient is then immediately spiral scanned
from 2 vertebral segments above the tip
of the catheter, down through the pump in
the abdomen.
Ct myelogram dye study
• Advantages:
– Improved sensitivity compared to plain
films and fluoroscopy
• Disadvantages:
– Technical expertise
– Coordination with radiology
– Poor soft tissue differentiation
Normal study
Contrast loculated in the spinal canal
Contrast ventral to CSF suggesting
subdural migration
Contrast extravasating into the subcutaneous
tissues suggesting catheter breakage
Contrast
filing
of an
intrathecal
granuloma
Nuclear medicine cisternogram
• Obtain flow rate and catheter volume
• Inject 0.5 mCi of In-111 DTPA into pump
reservoir
• Collect serial images (typically 24, 48 and 72
hrs)
Nuclear medicine cisternogram
Advantages
• Can perform study if you cannot aspirate from
side port
• Observe the native flow rate
Disadvantages
• Coordination with nuclear medicine
• Several days to obtain result
• Poor anatomic localization
Normal
nuclear
medicine
study
Catheter occlusion
with
focal collection
Pump
to
catheter
occlusion
MRI
Advantages
• Can perform study if you cannot aspirate from side
port
• Anatomic detail
Disadvantages
• Poor visualization of catheter
Meningeal Origin
Dura
Catheter
Arachnoid Layer
Thank
you