Northwestern University Department of Neurosurgery
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Transcript Northwestern University Department of Neurosurgery
Neurostimulation for Pain:
Neurosurgical Considerations
Joshua M. Rosenow, MD, FACS
Director, Functional Neurosurgery
Associate Professor, Department of Neurosurgery
Northwestern Memorial Hospital
Northwestern University Department of Neurosurgery
SCS: 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 Neurosurgery
Patient Factors
Set appropriate expectations!!!!
Takes time, but will be worth the investment
Prepare patients for the procedure
Involve them in the process
i.e. IPG placement
Northwestern University Department of Neurosurgery
Surgical 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
Northwestern University Department of Neurosurgery
General 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. 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
Northwestern University Department of Neurosurgery
Why use paddles?
Previous difficulties with perc leads
Preference of implanter
?lower current requirement
?less interference by epidural fat
Northwestern University Department of Neurosurgery
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.
Northwestern University Department of Neurosurgery
Paddle Leads
Northwestern University Department of Neurosurgery
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
Northwestern University Department of Neurosurgery
Paddle issues
Where does the paddle go?
Assessing canal adequacy for paddle
Clearing the epidural space
The paddle won’t go straight
Northwestern University Department of Neurosurgery
Guess the level!
Northwestern University Department of Neurosurgery
Communication is key
T9
T10
Northwestern University Department of Neurosurgery
Preop 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 Neurosurgery
Preop 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
Northwestern University Department of Neurosurgery
Paddle issues in the OR
Dissecting epidural space
Careful
You’re a surgeon – use surgical tools
No – paddle lead, passing device
Yes – 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 Neurosurgery
Epidural 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
Northwestern University Department of Neurosurgery
Complication 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
Northwestern University Department of Neurosurgery
Don’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”
Northwestern University Department of Neurosurgery
Don’t make more cases!
Northwestern University Department of Neurosurgery
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
Northwestern University Department of Neurosurgery
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
Infraclavicular
Cervical or lumbar SCS
ONS
Peripheral LE stimulation
Axillary
ONS
Cervical SCS
Trigeminal
ONS
DBS/MCS
Cervical SCS
UE peripheral stimulation
SQ lower extremity
Abdomen
DBS/MCS
ONS
SCS
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Conclusions
Rational treatment plan improves outcomes
Good patient selection important
Technique is key, as always
Goal: not “do implants” but TREAT PAIN
Northwestern University Department of Neurosurgery
Thank you for coming!
E-mail: [email protected]
Phone: 312-695-0495
Northwestern University Department of Neurosurgery
Northwestern University Department of Neurosurgery