Sacral Nerve Root Block

KEY FACTS

Terminology

• Selective corticosteroid and long-acting anesthetic injection of sacral nerve root at level of neural foramen

Preprocedure

• Malignant or benign neoplasm

• Imaging

  • Evaluate relevant anatomic landmarks

  • Search for other causes of patient pain

Procedure

• Anchor 22-gauge spinal needle in subcutaneous tissue and confirm trajectory with fluoroscopy

  • Right side: Target foramen at 1-2 o'clock

  • Left side: Target foramen at 10-11 o'clock

• Pain score

  • Note patient pain before, during, and after injection

  • Whether pain was reproduced during procedure

• Alternatives

  • Caudal epidural steroid injection

  • Lumbar nerve root block

  • Sacroiliac injection

Outcomes

• Expected

  • Reproduction of pain during injection

  • Significant relief of pain following injection

• Problems

  • Extraforaminal injection failure of pain control/false-negative study

  • Diagnostic failure: Wrong level or selected root not sole pain generator

  • Nerve root injury, bleeding, infection

  • Vasovagal reaction

TERMINOLOGY