Cordotomy

Procedure of choice for unilateral pain below the C5 dermatomal level (≈ nipple; occasionally pain as high up as the mandible may be treated), in a terminally ill patient.

If there is any contralateral pain, it will tend to be magnified following the procedure and often leads to dissatisfaction with cordotomy.

Better for aching pain,
Poor for central pain, dysesthesias, causalgia (deafferentation pain) midline visceral pain.
May be performed as an open procedure, but is more easily performed percutaneously at the C1–2 interspace (which limits the procedure to the cervical region).
If there is any bladder dysfunction, it will usually be worse following cordotomy.
Bilateral cervical cordotomies carries a risk of the loss of automaticity of breathing4 (one form of sleep apnea, so-called Ondine’s curse5).
Therefore, if bilateral cordotomies are desired, the second should be staged after normal respiratory function and CO2 responsiveness are verified following the first procedure, or the second stage may be done as an open procedure in the thoracic region.
Review the cross sectional spinal cord anatomy for relationships of the critical tracts (spinothalamic and corticospinal) to the dentate ligament, the anterior spinal artery, respiratory (▶Fig. 1.15), and bladder areas (▶Fig. 3.2).

Spirometric measurement of minute volume (MV) before and after breathing a mixture of 5% CO2 and 95% O2 for 5minutes.

If the MV decreases, these patients are at increased risk of having sleep apnea (usually transient),
No increased risk if MV increases or stays the same.
Also, patients with <50% of predicted values on PFTs are not candidates.
In patients with pulmonary cancer contralateral to the planned side of cordotomy, check that the contralateral diaphragm is functioning with fluoroscopy;

Otherwise, if the ipsilateral diaphragm is lost due to cordotomy, the patient may be hypopneic.