Epidural Lysis of Adhesions
Epidural lysis of adhesions refers to a percutaneous spinal procedure for pain relief (Racz procedure). Pain may occur due to epidural inflammation, nerve root compression, venous engorgement, and scar tissue. Under contrast-enhanced fluoroscopy, a steerable radiopaque catheter is used to deliver several drugs to the target “pain generator”; these include local anesthetics, hyaluronidase, hypertonic saline, and steroids. Contrast epidurography identifies correct placement and permits early detection of subarachnoid, subdural, or intravascular placement. Local anesthetics reduce intraoperative and postprocedural pain. An enzymatic agent (hyaluronidase) or mechanical motions (moving the catheter back and forth) are used to “loosen” peridural scar tissue. Hypertonic saline (10%) is used to reduce intraneural edema. Steroids modulate inflammation. This procedure was initially developed for patients with symptomatic epidural scarring, ie, post-laminectomy syndrome. Published studies report safe and efficacious outcomes following epidural lysis of adhesions for several spinal pain etiologies: failed back surgery syndrome, post-laminectomy syndrome, spinal stenosis, lumbar radiculopathy, and cervicalgia.
• Back/neck pain and sciatica (with or without surgery)
• Chronic low back pain
• Radiculopathy (mono- or polysegmental)
• Failed back surgery syndrome
• Lumbar spinal stenosis
• Post-laminectomy syndrome
• Spinal stenosis
• Neurogenic claudication
• Degenerative disc disease
• Herniated/prolapsed intervertebral disc
• Epidural scarring
• Sympathetically independent pain
• The epidural space is a potential space that surrounds the dural sac and is contained within the bony spinal canal.
• Ventrally, the epidural space is bounded by the vertebral body, intervertebral disc, and longitudinal ligament.
• Dorsally, the epidural space is bounded by the ligamentum flavum, lamina, and spinous processes.
• Laterally, the epidural space is bounded by the pedicles, facet joints, articular processes, and “foramina.”
• The bony spinal canal is contiguous from the foramen magnum to the sacral hiatus.
• Epidural needle access should be attempted at the sacral hiatus, interlaminar space, and only rarely, at the intervertebral foramen.
• The sacral hiatus is dorsally covered by the sacrococcygeal ligament and is laterally bounded by the sacral cornua. In thin patients, the hiatus is palpable.
• For the cervical, thoracic, and lumbar levels, a paramedian approach to the interlaminar space is advised.
• The interlaminar window may be optimally visualized when utilizing cephalocaudal angulation, during fluoroscopy.
• Optimal patient positioning helps with access.
• The lumbar lordosis should be reduced; the cervical or thoracic kyphosis should be accentuated. This “opens up” the interlaminar space and facilitates needle entry.
Patient selection and choice of this technique depend on an individualized risk/benefit analysis and a review of prior therapies. For instance, epidural lysis of adhesions may be the index procedure in a patient with failed back surgery syndrome. On the other hand, this procedure may be used late in the treatment algorithm for patients with spinal stenosis.
Contraindications (relative or absolute) and indications for procedure termination include:
• Infection, systemic or localized
• Distorted or complicated anatomy
• Progressive neurological deficit
• Allergy to procedural drugs, eg, iodinated contrast
• Open wound or skin ulceration
• Poorly controlled diabetes
• Patient refusal or lack of health care proxy
• Inability to lie prone or on the side, for the duration of the procedure
• Intraoperative recognition of subarachnoid, subdural, or vascular uptake
• Severe pain during injection
• Patients should have constant pain >6/10 and functional limitations.
• Withhold coagulopathic medications for appropriate lengths of time as per protocol.
• Diabetic patients may need blood sugar testing.
• Female patients of childbearing age should have an AM urine pregnancy test or a serum pregnancy test.
• Airway, cardiopulmonary, and neurological assessment is required as per protocol.
• Intravenous access is advised, particularly for patients receiving cervical or thoracic procedures.
• These are mandatory for patients receiving intravenous anxiolytics and analgesics.
• Cardiopulmonary safe guards, such as resuscitation equipment, should be present within the procedure suite.
• Patients should sign witnessed informed consent, which includes an evidenced based discussion about indications, efficacy, and safety.
• Preprocedure site marking/initialing with an indelible marker site and site verification is utilized in most US-based hospitals. This reduces the risk of wrong site or wrong location surgery.
Prone or lateral decubitus
• Tip: accentuate cervical/thoracic kyphosis and reduce lumbar lordosis, by using properly placed pillows.
• Anterior-posterior (AP) image of the spine (cervical, thoracic, and lumbar), sacrum, or coccyx
• Cephalocaudal angulation
“Opens up” interlaminar window
Best view to identify sacral hiatus
INTRAOPERATIVE TECHNICAL STEPS
• Intravenous sedation: fentanyl, meperidine, midazolam
Patient should be able to communicate
Real time sensory and motor monitoring
• Prone position
Pillow under abdomen to flatten back
Pillow under the chest to accentuate cervical kyphosis
• Noninvasive monitoring: pulse oximetry, electrocardiography sensors, blood pressure
• Sterile prep and drape; extended drape over feet
Legs abducted and toes pointing inward (pigeon toes) for caudal approach
Arms to the side or swimmer’s position for cervical approach (optimize lateral view)
Palpate and identify sacral hiatus or spinous process (especially for cervical access)
Confirm with fluoroscopy
• Sacral hiatus access
Local anesthetic skin wheal (1%-2% lidocaine)
1 to 2 cm below sacral hiatus
18-gauge venipuncture needle to puncture skin
Advance under lateral fluoroscopy
• Interspinous access (cervical-thoracic-lumbar)
Palpate and identify C7, T1, T2 spinous processes
Local anesthetic skin wheal 3 to 4 cm below level
Tip: use intermittent lateral (depth), posteroanterior (direction), and lateral (depth) views
Tip: advance epidural access needle to base of spinous process (spinolaminar line)
Tip: shallow angle of entry, 30 degrees
• Rotate C-arm to posteroanterior view
Tip: at sacral hiatus, do not advance needle past S3-4 foramen
• Remove stylet and replace with pulsator syringe
Loss of resistance
Tip: flat or shallow needle entry into epidural space is optimal
• Confirm negative aspiration of blood, cerebrospinal fluid
• Real-time fluoroscopic contrast instillation (iohexol, iopamidol)
Nonionic, iodinated dye
Limited literature on gadolinium or gadopentetate in iodine allergies
• 1 mL to evaluate for vascular uptake, subarachnoid (myelographic), or subdural spread
Subarachnoid—enter at different level or abandon procedure
subdural injection—consider repositioning
Muscular spread (short segmental muscles)—contrast dorsal to spinous process—advance further
Dorsal coccygeal spread—reposition needle to enter sacral hiatus
• 5 to 9 mL to identify epidurogram—“Christmas tree” pattern
Tip: this step may be optional
Lysis of adhesions was developed in a period predating MRIs, hence the need for identifying epidural filling defects
Tip: in my practice, I inject 1 to 2 mL to confirm epidural placement at this stage
• Radiopaque catheter introduction (Tunl-XL or Brevi-XL catheter)
Directional steering can be carried out by rotating needle or “aiming” needle
Catheter will then pass in the direction of the needle
Alternatively, the catheter may be bent 15 degrees about 2 cm proximal to the tip
Tip: an early trajectory is the best approach, since distal manipulation is harder
Tip: at cervical, thoracic, or lumbar levels, the catheter can be passed ipsilaterally or contralaterally to the target site
Tip: the catheter may have to be pulled back into the needle
Tip: needle orientation should be the same when pulling back the catheter, as when pushing it out (to reduce risk of shearing)
• Steered under fluoroscopy to ventrolateral epidural space
Catheter resistance may be encountered due to adhesions, disc bulging, stenosis, epidural fat, hardware
Mechanical catheter manipulation may be necessary to place catheter effectively
• Contrast (water soluble, nonionic) is instilled via the catheter to confirm epidurogram or “neurogram”
Injection resistance may be present due to the high viscosity of contrast
Tip: verify that the catheter is not kinked
Contact with nerve may elicit dysesthesias along arm, chest well, or leg
Check for absence of vascular, subarachnoid, and subdural spread
• Epidural filling defect may or may not be present
• Medication delivery
Local anesthetic (5-10 mL)
Bupivacaine or levobupivacaine 0.25%
Betamethasone (6 mg)
Dexamethasone (4 mg)
Triamcinolone (40 mg)
Methylprednisolone (40 mg)
Hyaluronidase 900 to 1500 units (dose depends on spinal level)
Cervical (900 units)
Thoracic (1200 units)
Lumbosacral (1500 units)
Slow delivery or slow infusion
3 mL increments over 10 to 15 minutes (no neurological changes prior to instillation)
If spasms are present, consider reinstillation of lidocaine 1%
• Remove needles
• Dressing applied
• Neurologic examination should not change
• Pain may be exacerbated
• Monitoring of potential complications
• Temperature, heart rate, respiratory rate, blood pressure, neurologic examination, orientation status, pain relief, self-ambulation, and voiding should be noted prior to discharge. Sedation may require monitoring for 1 hour. Patients are not allowed to drive for up to 24 hours
CLINICAL PEARLS AND PITFALLS
• Liberal use of lateral and posteroanterior views are needed
• Use a 2-handed technique for obtaining loss of resistance
One hand on the pulsator syringe
The other hand is on the patient’s skin and slowly advancing the needle (if the patient suddenly moves backward, the second hand can stabilize the needle)
• Proper patient positioning is imperative, particularly in obese and osteoporotic patients
Use pillows to facilitate access
Several large clinical trials have attested to the safety and efficacy of epidural lysis of adhesions.