Cordotomy is the name of a surgical procedure aimed at destroying the pain-conducting tracts of the spinal cord. First performed in 1912 by neurosurgeons William Spiller and Edward Martin, they found the cordotomy to be effective at decreasing temperature and pain sensations in patients which suffer from painful conditions. It was originally widely used for chronic pain, but now it has been adapted for use in cancer patients only. The open procedure is rarely performed due to the high risk and complication rates observed previously.
The open method underwent further adaptation to a percutaneous cervical cordotomy in 1963. In the 1990s, with improvements in pain management, the cordotomy again fell out of favor. However, it is still a palliative option for therapy-resistant pain. Given the population which receives this procedure, there is severely limited availability of studies testing its long-term effects. There is a case study of a patient with seminoma who underwent a right-sided percutaneous cervical cordotomy and chemotherapy. The physicians found the patient, five years later, to have continued sensory impact with minimal impact on motor and autonomic function.
Today with the percutaneous cervical cordotomy, the nociceptive pathways in the lateral spinothalamic tract anterolateral column are destroyed in the cervical spinal cord at the level of C1-C2.
The original approach focused on pain relief for patients with unilateral malignancies, lower extremity pathologies, failed back syndrome, chronic nociceptive painful conditions, and cancer patients. On the other hand, bilateral cordotomies for visceral or bilateral pain is also an option. In the more recent percutaneous approach, destruction of the lateral spinothalamic at the level of C1-C2 results in a contralateral disruption of painful sensations beyond C4. Today, this latter approach is most commonly used in patients with limited life expectancy and suffering from opioid-resistant cancer pain. Irrespective of the procedure or technique, one uniform indication for this intervention is having severely intractable pain which has not responded to conventional therapies. Cancer-related pain is an indication, but not a requirement as it can be done in populations suffering other irreversible painful conditions. Pain severity level is essential when considering appropriate indications. The patient's pain must have advanced to level 3 of the World Health Organization pain ladder before considering this invasive procedure.
The cordotomy has been documented as particularly impactful for pain secondary to mesothelioma, Pancoast syndrome, and lung cancer.
Percutaneous cordotomy is contraindicated in patients with a coagulation disorder, severely reduced ventilator function, and if a patient is unable to cooperate. Several alternative procedures were developed in the 20th century. The commissural myelotomy was developed for bilateral pain arising from pelvic or abdominal neoplastic disease. Likewise, the punctate or limited midline myelotomy also aimed at pelvic and abdominal visceral pain. Therefore, if patients have pain solely localized to these regions, the cordotomy can be avoided and these newer procedures adopted. With the introduction of intrathecal pumps and spinal cord stimulators, it is prudent to steer many patients away from cordotomies.
Most cordotomies utilize the percutaneous approach at the level of C1-C2. The surgeon often uses fluoroscopic or CT guidance. Patients are usually awake for the procedure which is performed under local anesthesia. A laminectomy is required to execute an open cordotomy. It comes with a lengthier recovery and a higher risk of side effects. However, when percutaneous cordotomy is unfeasible, especially in children, the open procedure is preferred.
Only experience serious post-procedure side effects. They include dysesthesia, urinary retention, ataxia, paresis, sympathetic dysfunction (hypotension, Horner’s syndrome and bladder dysfunction), sexual sensitivity impaired or lost, and a form of sleep apnea (acquired central hypoventilation syndrome). The bulk of these complications result from the accidental division of the unintended reticulospinal tracts. Another serious complication is spontaneous new pain. New pain may be old (previously extant) pain which was previously unrecognized and now unmasked by removing prior distractions. Likewise, new pain can be viewed as an unpreventable complication from the interruption of nociceptive pathways.
Overall, the risk of severe complications with unilateral cordotomy is low. Procedure-related mortality is reported in the range of 1%-6% which is mainly due to respiratory dysfunction. With more accurate ablation techniques, no respiratory dysfunction is rare.
Percutaneous cervical cordotomy is recommended for patients with a life expectancy of fewer than six months and who also meet the pain severity indications. It is a palliative procedure. Successful, immediate pain relief results in approximately three-quarters of patients. However, the rate of pain relief declines to less than 50% after two years. As was noted earlier, new pain syndromes can also arise, unfortunately, and patients must be aware and be willing to accept that risk. As a depiction of efficacy and clinical significance and side effects, there is a study which showed diminished touch perception on the left side of the body which points to likely an anterior spinothalamic tract lesion. The nearby anterior spinocerebellar (mediating proprioception), reticulospinal (mediating autonomic outflow) and cerebrospinal (mediating voluntary movement) tracts were deemed unaffected given no signs of ataxia, autonomic issues, or motor dysfunction.
The cordotomy is a palliative procedure. It is often performed on patients with a life expectancy under six months and comes with significant risks and with possible significant benefits. Obtaining a thorough history is essential, and questioning by the clinician should show empathy to the patient and their condition, whether it be a malignancy or other pathology. This decision is not to be made alone or lightly by the patient, family, or a clinician. Patients must not feel rushed when having their options for intractable pain laid out before them. Furthermore, this is a surgical procedure, so interdisciplinary approaches to conversations must take place. Dialogue should take place between the palliative physician, the surgeon, the oncologist, and the primary physician. Each specialty should be involved with helping the patient make an informed decision which the patient feels is best for their own goals of care. As always, especially in palliative care patients with often many co-morbidities, the patient's medical history and background should be clearly defined to members of the patient's healthcare team. Any deviation from thoroughness can create significant challenges and risks for the patients, their family, and their clinicians. Medical errors are to be actively avoided. If any particular clinician feels that significant palliative procedures, such as the cordotomy, are not the best choice for the patient, they should tactfully bring up their concern to the other clinicians involved in that patient's care. This approach ensures that they have a full and clear understanding of the procedure, risks, and benefits prior to approaching the patient with their professional opinion.