What is rhizotomy, its indications, procedural techniques, and postoperative care?

Rhizotomy Overview

Rhizotomy is a neuroablative procedure that selectively destroys nerve roots to reduce pain or spasticity, with distinct applications in cancer pain management and pediatric spasticity, utilizing either percutaneous radiofrequency/chemical techniques or open surgical approaches.

What is Rhizotomy?

Rhizotomy involves the surgical or percutaneous ablation of nerve roots (dorsal sensory roots or their branches) to interrupt pain transmission or reduce spasticity. The procedure can target:

• Spinal nerve roots (for body pain or spasticity)
• Cranial nerve roots (for craniofacial pain)
• Medial branches of dorsal rami (for facet joint pain)

The technique varies from minimally invasive percutaneous radiofrequency ablation to open surgical sectioning of nerve rootlets.

Primary Indications

Cancer Pain (Level III Evidence)

For unilateral somatic nociceptive/neuropathic body cancer pain, rhizotomy in both percutaneous radiofrequency/chemical and open surgical forms may be used, though sensory deficits are expected and motor or autonomic deficits may occur depending on nerves ablated 1.

For craniofacial cancer pain, cranial nerve rhizotomy represents one option alongside trigeminal tractotomy and nucleus caudalis DREZ 1.

Pediatric Spasticity

Selective dorsal rhizotomy (SDR) is the gold standard neurosurgical treatment for reducing lower-extremity spasticity in children with cerebral palsy 2. Universal suitable candidates include:

• Bilateral spastic cerebral palsy
• Gross Motor Function Classification System (GMFCS) levels II or III
• Ages 5-7 years (optimal window)
• Adequate strength and motor control
• Access to intensive postoperative rehabilitation 2

Chronic Spine Pain - STRONG RECOMMENDATION AGAINST

For non-cancer chronic axial spine pain, facet joint radiofrequency ablation (rhizotomy) should NOT be offered outside clinical trials 3. The 2025 BMJ guideline provides strong recommendations against these procedures due to lack of meaningful benefit on quality of life, despite contradictory recommendations from some pain societies.

Procedural Techniques

Selective Dorsal Rhizotomy (SDR) for Spasticity

Two main surgical approaches exist:

Single-level technique (preferred at high-volume centers):

• Single laminectomy at conus level (typically L1-L2)
• Advantages: decreased operating time, less postoperative pain, minimal risk of spinal instability
• Visualizes all dorsal roots through one exposure 4

Multilevel technique (Peacock/Park methods):

• L1-S1 laminectomy or laminoplasty
• Direct visualization of roots at each foraminal exit 4

Intraoperative monitoring is mandatory:

• Electrophysiological monitoring guides rootlet selection
• Abnormal discharge patterns identify pathological rootlets
• Typically 25-50% of rootlets are sectioned based on electrophysiology 5

Percutaneous Rhizotomy for Cancer Pain

• Radiofrequency (RF) or chemical ablation
• Fluoroscopic or CT guidance
• Targets specific nerve roots causing pain 1

Endoscopic Rhizotomy for Facet Pain

Despite the strong recommendation against use in non-cancer chronic pain 3, endoscopic rhizotomy (ER) shows longer duration of relief than radiofrequency ablation when used, particularly in lumbar spine (though this should only occur in research settings per current guidelines) 6.

Postoperative Care

Pain Management After SDR

Multimodal analgesia with epidural catheter is superior to patient-controlled analgesia (PCA):

• Intraoperative epidural catheter placement with continuous opioid infusion
• Avoids ICU admission (100% of PCA patients required ICU vs. 0% with protocol) 7
• Reduces side effects: pruritis treatment needed in 15% vs. 57% with PCA 7
• Duration: typically 24 hours to 7 days depending on center protocol 8
• Pain scores average 1.5 on postoperative day 0, decreasing to 0.5 by day 3 7

Monitor for:

• Oxygen desaturations (occur in 41% but rarely require intervention) 7
• CSF leak (rare, approximately 1 in 1500 cases) 4
• Nausea/vomiting (treat prophylactically)

Rehabilitation After SDR

Intensive rehabilitation is mandatory and begins immediately:

• Acute phase: Intensive daily physical therapy starting postoperative day 1
• Duration: Varies by center from weeks to months of intensive therapy 2
• Long-term: Less intensive ongoing program for 6-12 months
• Critical point: Lack of access to intensive postoperative rehabilitation is an absolute contraindication to SDR 2

Follow-up

• Pain assessment using validated scales (70% of centers use formal pain scales) 8
• Functional outcome measures at 3,6,9, and 12 months 6
• Monitor for progressive spinal instability (rare with single-level technique) 4

Critical Caveats

For cancer pain: Sensory deficits are inevitable; motor and autonomic deficits may occur. Serious adverse events are relatively uncommon but include infection, paralysis (rare), and death (very rare with epidural approaches) 1, 3.

For SDR: Patient selection is paramount. Children outside GMFCS II-III, those with inadequate strength/motor control, or without access to intensive rehabilitation are poor candidates 2.

Avoid the trap: Do not offer facet joint rhizotomy/radiofrequency ablation for chronic non-cancer spine pain based on older pain society guidelines—the highest quality 2025 evidence strongly recommends against this practice 3.