Epidural Lysis of Adhesions

CHAPTER 40 Epidural Lysis of Adhesions

Rinoo V. Shah

INTRODUCTION

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.

INDICATIONS

• 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

RELEVANT ANATOMY

• 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.

PREOPERATIVE CONSIDERATIONS

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

• Coagulopathy

• 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

• Hypotension

PREOPERATIVE PREPARATION

• 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.

PATIENT POSITIONING

Prone or lateral decubitus

• Tip: accentuate cervical/thoracic kyphosis and reduce lumbar lordosis, by using properly placed pillows.

FLUOROSCOPIC VIEWS

• Anterior-posterior (AP) image of the spine (cervical, thoracic, and lumbar), sacrum, or coccyx

Localize level

Identify midline

• Cephalocaudal angulation

“Opens up” interlaminar window

• Lateral

Guides depth

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)

• Fluoroscopy

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

Introducer needle (angiocatheter, RX Coude needle)

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)

Lidocaine 1%

Ropivacaine 0.25%

Bupivacaine or levobupivacaine 0.25%

Steroids

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)

10% preservative free hypertonic saline (3-10 mL may be used)

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

• Bandage

POSTPROCEDURE CONSIDERATIONS

• 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)