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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