Neuroablative procedures: cordotomy and neurolytic blocks

Cordotomy lesions the spinothalamic tract opposite the pain and suits unilateral, somatic or neuropathic cancer pain below C4 in patients with limited life expectancy; neurolytic plexus blocks target visceral pain.

1. Spinothalamic fibers cross near entry. Second-order neurons cross in the anterior commissure and ascend contralaterally, so cordotomy lesions the anterolateral tract opposite the painful side ¹.
2. Percutaneous cordotomy is done at C1–C2. It is typically CT-guided, with lesion placement confirmed by impedance monitoring and electrophysiological testing ¹.
3. Select candidates carefully. Ideal candidates have unilateral pain below the C4 dermatome, life expectancy under 1–2 years and failure of conservative care; mesothelioma and Pancoast tumor are classic examples. Assessment should include biopsychosocial and spiritual factors ².
4. Somatic and neuropathic pain respond; visceral does not. Cordotomy is not recommended for visceral pain, which travels with the autonomic system; coagulopathy, local infection or tumor, and distorted anatomy are absolute contraindications ².
5. Celiac neurolysis treats upper abdominal visceral pain. Alcohol destroys visceral afferent and sympathetic fibers; unopposed parasympathetic activity commonly causes transient diarrhea, and splanchnic vasodilation orthostatic hypotension ³.
6. Know the plexus territories. The superior hypogastric plexus serves pelvic organs such as bladder, uterus and rectum; the ganglion impar serves the perineum, distal rectum, anus, distal urethra, vulva and distal vagina ³.

Bilateral high cervical cordotomy carries a much higher risk of severe complications, including respiratory dysfunction and Ondine's curse; bilateral pain and poor respiratory function count against cordotomy ¹².

• Percutaneous cordotomy gives immediate, substantial analgesia in over 90% of patients, with about 80% reporting lasting relief at last follow-up ¹.
• Mirror pain after cordotomy is reported in 9–63% of patients; Horner syndrome and orthostatic hypotension are other side effects ².
• Cordotomy respiratory depression is reported in up to 10%; urinary retention in up to 11% ².
• Fever on the first day after cordotomy is reported in 90–100% ².
• Light touch is spared after cordotomy because it travels in the dorsal columns ².
• Serious neurologic complications occur in under 1% of celiac neurolysis procedures; paraplegia may follow injury to the artery of Adamkiewicz ³.
• Central hypoventilation is more common after bilateral ablation, from damage to both reticulospinal tracts carrying medullary respiratory control ¹.
• Dehydrated alcohol is the most commonly used neurolytic agent for celiac neurolysis ³.

• Lesioning the spinothalamic tract on the same side as the pain ¹.
• Offering cordotomy for diffuse visceral pain ².
• Performing a prophylactic bilateral cordotomy to prevent mirror pain ¹².
• Expecting celiac neurolysis to cause constipation and hypertension rather than diarrhea and orthostatic hypotension ³.