Principles of Intradural Spine Surgery

Imaging

Magnetic resonance imaging (MRI) with or without contrast
- Establishes rostrocaudal extent of lesion and relationship to cord
- Helps with axial plane location
- Presence of cystic caps may suggest ependymoma
- May show additional lesions (e.g., tumor or syrinx) elsewhere
Computed tomography: can show spinal dysraphism
- May show calcification of pathology
- Can give idea of bone quality
- Helpful if instrumentation may be needed
Myelography
- Gives basic localization of pathology
- With delayed views can give idea of CSF flow, syrinx uptake
- Helpful if patient cannot have MRI (e.g., pacemaker)
- Does not show intramedullary details
- May have risk if complete block; consider C1-2 puncture

Equipment

Typical

Consider having available

Ultrasonic aspirator with small tip (for debulking larger lesions)

Intraoperative ultrasound (may be helpful for localization)

Lumbar drain kit (for cases with higher risk of dural leak)

Dural patch material (e.g., AlloDerm [LifeCell Corporation, Branchburg, NJ], suturable DuraGen)

Dural sealant (e.g., Tisseel, DuraSeal)
Monitoring generally used
- Somatosensory evoked potentials
- Motor evoked potentials
- Sphincter electromyography may be helpful for some lesions (e.g., conus, sacral)
Preoperative marking:
- Consider using to aid intraoperative localization for areas that are harder to image intraoperatively (e.g., mid-thoracic)

Anesthesia

Positioning/Approach

Intradural Procedure

Closure

Watertight dural closure (with dural patch where needed)
Test dural closure with intraoperative Valsalva challenge
The author generally minimizes use of subfascial surgical drains as they potentially could promote CSF leak but recognizes that there is disagreement on this topic
Consider a layer of muscle sutures to reduce dead-space
Meticulous fascial closure (e.g., 0 Vicryl)
Running locked skin suture (e.g., 3–0 nylon)
Consider intraoperative spinal drain with high dural leak risk

Rapid steroid taper if neurologically unchanged
Perioperative antibiotics
Bed rest for 48 hour (e.g., head of bed 0 to 15 degrees for 24 hours, 0 to 30 degrees for 24 hours, then mobilize; perhaps can accelerate for cervical levels)