Neurostimulation for Pain: Neurosurgical Considerations
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Transcript of Neurostimulation for Pain: Neurosurgical Considerations
Northwestern University Department of NeurosurgeryNorthwestern University Department of Neurosurgery
Neurostimulation for Pain: Neurostimulation for Pain:
Neurosurgical ConsiderationsNeurosurgical Considerations
Joshua M. Rosenow, MD, FACSJoshua M. Rosenow, MD, FACSDirector, Functional Neurosurgery
Associate Professor, Department of Neurosurgery
Northwestern Memorial Hospital
Northwestern University Department of NeurosurgeryNorthwestern University Department of Neurosurgery
SCS: Patient SelectionSCS: Patient Selection
Pain syndrome amenable to stimulation Radicular preferable to axial Neuropathic preferable to nociceptive
Failed reasonable medical management Several pharmacologic classes Dose titration until adverse side effects or lack of response noted
Surgical disease ruled out Reoperation vs. stim? Not surgical candidate?
Pain psychological evaluation
*North, et al. Stereotact Funct Neurosurg 1994;62:267-272.
Northwestern University Department of NeurosurgeryNorthwestern University Department of Neurosurgery
Patient FactorsPatient Factors
Set appropriate expectations!!!! Takes time, but will be worth the investment
Prepare patients for the procedureInvolve them in the process
i.e. IPG placement
Northwestern University Department of NeurosurgeryNorthwestern University Department of Neurosurgery
Surgical ContraindicationsSurgical Contraindications
Thecal sac compression/significant spinal stenosis
Significant spinal deformity
Severe emaciation
Significantly low WBC, plt
Coagulopathy
Ongoing infection
Inability to assess patient response to trial
Psychological contraindications
Patient compliance issues
Medication abuse issues
Unsuccessful trial
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General PrinciplesGeneral Principles
Adequate length of trial
Choose appropriate hardware
Simulate everyday life during trial, within limits
Confirm location and ensure stability of electrode
Prevent infection
Prepare for permanent implant
Permanent system should be stable, flexible and convenient
Prepare for revisions
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MAC vs. GETAMAC vs. GETA
Airway/body habitus
Comorbidities
Procedure to be performed/region of operation
Anticipated intraoperative difficulties
Need for intraoperative verification of coverage
Patient preference
Patient ability/willingness to cooperate
If GETA - consider neuromonitoring for protection and confirmation
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Why use paddles?
Previous difficulties with perc leads
Preference of implanter
?lower current requirement
?less interference by epidural fat
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Paddle Trials
Lumbar fusion or laminectomy precluding
percutaneous insertion
Inability to access the epidural space
percutaneously
Bony anatomy
Obesity
Prior procedure in the region of the implant
Tumor resection, etc.
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Paddle LeadsPaddle Leads
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Laminotomy Lead Placement
Plan incision centered 1 disc space below desired entry point Incision centered on T10-11 will lead to entry at T9-10
and paddle will cover T8-9 bodies
Rongeur both upper and lower spinous processes to
flatten angle
Small central lamintomy through ligamentum flavum
Carefully dissect epidural space and insert electrode
Avoid pressure on spinal cord
Securely anchor to deep tissues
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Paddle issuesPaddle issues
Where does the paddle go?
Assessing canal adequacy for paddle
Clearing the epidural space
The paddle won’t go straight
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Guess the level!Guess the level!
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Communication is keyCommunication is key
T9T9
T10T10
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Preop imaging is essentialPreop imaging is essential
You would never do any other spine case without adequate preop imaging – DON’T START NOW
Preop imaging makes sure something asymptomatic doesn’t become symptomatic
Aids in counseling patient preop if procedure needs to be altered to deal with anatomic issue
Northwestern University Department of NeurosurgeryNorthwestern University Department of Neurosurgery
Preop imaging is essentialPreop imaging is essential
Where is the cord???
The cord may not respect the spinal column midline
Paddle may look great on fluoro and not provide adequate coverage
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Paddle issues in the ORPaddle issues in the OR
Dissecting epidural space Careful You’re a surgeon – use surgical tools
No – paddle lead, passing deviceYes – dural separator, narrow tip malleable brain ribbon
Anywhere but straight Straight paddle in curved space Epidural adhesion Unilateral extension vs. “reach around” laminotomy
Northwestern University Department of NeurosurgeryNorthwestern University Department of Neurosurgery
Epidural fibrosisEpidural fibrosis
Careful dissection
Use appropriate instruments
Don’t over-reach
Decompress if you need to do so
Suture paddle to dura if possible
Fibrin glue
Postop abdominal pain
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Complication avoidanceComplication avoidance
Don’t be overzealous
Don’t push a bad situation If it won’t go, it won’t go…
Caution when dissecting laterally – epidural veins
Poor coverage despite radiographic adequacy check trial fluoros make sure c-arm aligned in both planes
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Don’t be THAT surgeonDon’t be THAT surgeon
Paddle placed under GETA
Awoke with right thoracic radicular pain
Never had good coverage with stim
Surgeon told him to “wait a year and see if the coverage and pain improve”
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Don’t make more cases!Don’t make more cases!
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To Extend or Not to Extend
PRO Adds slack to system May make revision less invasive May be needed to adapt electrodes to IPG Needed for “permanent trial”
CON Another electrical connection Another wire that may break Connector adds bulk and may not be suitable for some locations Direct connection to IPG may reduce slack in system and add tension to
electrode
In either case, there should be a relaxing loop of electrode in the electrode incision site
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IPG Considerations
Location location location Patient comfort Cosmesis Ease of remote interface Ease of recharger interface (if rechargeable) Ease of implant Ease of revision
Rechargeable vs. Primary cell
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Possible IPG Locations
Buttock Cervical or lumbar SCS ONS Peripheral LE stimulation
Axillary ONS Cervical SCS
Abdomen DBS/MCS ONS SCS
Infraclavicular Trigeminal ONS DBS/MCS Cervical SCS UE peripheral stimulation
SQ lower extremity
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ConclusionsConclusions
Rational treatment plan improves outcomes
Good patient selection important
Technique is key, as always
Goal: not “do implants” but TREAT PAIN
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E-mail: E-mail: [email protected]@nmff.org
Thank you for coming!Thank you for coming!
Phone: Phone: 312-695-0495312-695-0495
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