Cordotomy for Intractable Cancer Pain: A Narrative Review

Background: Cordotomy is an invasive procedure for the management of intractable pain not controlled by conventional therapies, such as analgesics or nerve block. This procedure involves mechanical disruption of nociceptive pathways in the anterolateral column, specifically the spinothalamic and spinoreticular pathways to relieve pain while preserving fine touch and proprioceptive tracts. Objectives: The purpose of this review article is to refresh our knowledge of cordotomy and support its continued use in managing intractable pain due to malignant disease. Study Design: This is a review article with the goal of reviewing and summarizing the pertinent case reports, case series, retrospective studies, prospective studies, and review articles published from 2010 onward on spinal cordotomy. Setting: The University of Texas, MD Anderson Cancer Center. Methods: PubMed search of keywords “spinal cordotomy,” “percutaneous cordotomy,” or “open cordotomy” was undertaken. Search results were organized by year of publication. Results: Cordotomy can be performed via percutaneous, open, endoscopic, or transdiscal approach. Percutaneous image-guided approach is the most well-studied and reported technique compared with others, with relatively good pain improvement both in the postoperative and shortterm period. The use of open cordotomy has diminished significantly in recent years because of the advent of other less invasive approaches. Cordotomy in children, although rare, has been described in some case reports and case series with reported pain improvement postprocedure. Although complications can vary broadly, some reported side effects include ataxia and paresis due to lesion in the spinocerebellar/corticospinal tract; respiratory failure due to lesion in the reticulospinal tract; or sympathetic dysfunction, bladder dysfunctions, or Horner syndrome due to unintentional lesions in the spinothalamic tract. Limitations: Review article included literature published only in English. For the studies reviewed, the sample size was relatively small and the patient population was heterogeneous (in terms of underlying disease process, duration of symptoms, previous treatment attempted and length of follow-up). Conclusions: Cordotomy results in selective loss of pain and temperature perception on the contralateral side, up to several segments below the level of the disruption. The plethora of analgesics available and advanced technologies have reduced the demand for cordotomy in the management of intractable pain. However, some patients with pain unresponsive to medical and procedural management, particularly malignant pain, may benefit from this procedure, and it is a viable treatment option especially for patients with a limited life expectancy whose severe, unilateral pain is unresponsive to analgesic medications. Key words: Cancer pain, cordotomy complications, cordotomy indications, intractable pain, open cordotomy, percutaneous cordotomy

Magnetic Resonance-Based Radiomic Analysis of Radiofrequency Lesion Predicts Outcomes After Percutaneous Cordotomy: A Feasibility Study

BACKGROUND To date, there is limited data on evaluation of the cordotomy lesion and predicting clinical outcome. OBJECTIVE To evaluate the utility of magnetic resonance (MR)-based radiomic analysis to quantify microstructural changes created by the cordotomy lesion and predict outcome in patients undergoing percutaneous cordotomy for medically refractory cancer pain. METHODS This is a retrospective interpretation of prospectively acquired data in 10 patients (5 males, age range 43-76 yr) who underwent percutaneous computed tomography-guided high cervical cordotomy for medically refractory cancer pain between 2015 and 2016. All patients underwent magnetic resonance imaging (MRI) of the cordotomy lesion on postoperative day 1. After segmentation of T2-weighted images, 310 radiomic features were extracted. Pain outcomes were recorded on postoperative day 1 and day 7 using the visual analog scale. R software was used to build statistical models based on MRI radiomic features for prediction of pain outcomes. RESULTS A total of 20 relevant radiomic features were identified using the maximum relevance minimum redundanc method. Radiomics predicted postoperative day 1 pain scores with an accuracy of 90% (P = .046), 100% sensitivity, 75% specificity, 85.7% positive predictive value, and 100% negative predictive value. The radiomics model also predicted if the postoperative day 1 pain score was sustained on postoperative day 7 with an accuracy of 100% (P = .028), 100% sensitivity, 100% specificity, and 100% positive and negative predictive value. CONCLUSION MR-based radiomic analysis of the cordotomy lesion was predictive of pain outcomes at 1 wk after percutaneous cordotomy for intractable cancer pain.

Percutaneous Cordotomy for Cancer-Associated Pain

Percutaneous cordotomy is well-established as a safe and effective treatment of cancer-associated pain. It remains a first-line treatment in countries where more expensive treatments such as implantable neurostimulators and pumps are not routinely available. We present a case report of a patient with metastatic adenocarcinoma of the esophagus and refractory right upper extremity pain, who was successfully treated via percutaneous CT-guided cordotomy. The procedure was completed in an outpatient setting; the patient was discharged after several hours, with immediate pain relief. He continued to benefit from the procedure for several months until he succumbed to his disease. The technique, decision making, complication profile, as well as the existing experience are presented and discussed in detail.

Pain Neurosurgery

Part of the Neurosurgery by Example series, this volume on pain neurosurgery presents exemplary cases in which renowned authors guide readers through the assessment and planning, decision making, surgical procedure, after care, and complication management of common and uncommon disorders. The cases explore the spectrum of clinical diversity and complexity within pain neurosurgery, including trigeminal neuralgia, postherpetic neuralgia, occipital neuralgia, percutaneous cordotomy for cancer-associated pain, chronic lumbar radiculopathy, and more. Each chapter also contains ‘pivot points’ that illuminate changes required to manage patients in alternate or atypical situations, and pearls for accurate diagnosis, successful treatment, and effective complication management. Containing a focused review of medical evidence and expected outcomes, Pain Neurosurgery is appropriate for neurosurgeons who wish to learn more about a subspecialty, and those preparing for the American Board of Neurological Surgery oral examination.

Microendoscopy-guided percutaneous cordotomy for intractable pain: case series of 24 patients

OBJECT The aim of this study was to show that microendoscopic guidance using a double-channel technique could be safely applied during percutaneous cordotomy and provides clear real-time visualization of the spinal cord and surrounding structures during the entire procedure. METHODS Twenty-four adult patients with intractable cancer pain were treated by microendoscopic-guided percutaneous radiofrequency (RF) cordotomy using the double-channel technique under local anesthesia. A percutaneous lateral puncture was performed initially under fluoroscopy guidance to localize the target. When the subarachnoid space was reached by the guiding cannula, the endoscope was inserted for visualization of the spinal cord and surrounding structures. After target visualization, a second needle was inserted to guide the RF electrode. Cordotomy was performed by a standard RF method. RESULTS The microendoscopic double-channel approach provided real-time visualization of the target in 91% of the cases. The other 9% of procedures were performed by the single-channel technique. Significant analgesia was achieved in over 90% of the cases. Two patients had transient ataxia that lasted for a few weeks until total recovery. CONCLUSIONS The use of percutaneous microendoscopic cordotomy with the double-channel technique is useful for specific manipulations of the spinal cord. It provides real-time visualization of the RF probe, thereby adding a degree of safety to the procedure.

Usefulness of Cordotomy in Patients With Cancer Who Experience Bilateral Pain

BACKGROUND: Although mirror pain occurs after cordotomy in patients experiencing unilateral pain via a referred pain mechanism, no studies have examined whether this pain mechanism operates in patients who have bilateral pain. OBJECTIVE: To assess the usefulness of cordotomy for bilateral pain from the viewpoint of increased pain or new pain caused by a referred pain mechanism. METHODS: Twenty-six patients who underwent percutaneous cordotomy through C1-C2 for severe bilateral cancer pain in the lumbosacral nerve region were enrolled. Pain was dominant on 1 side in 23 patients, and pain was equally severe on both sides in 3 patients. Unilateral cordotomy was performed for the dominant side of pain, and bilateral cordotomy was performed for 13 patients in whom pain on the nondominant side developed or remained severe after cordotomy. RESULTS: After unilateral cordotomy, 19 patients (73.1%) exhibited increased pain, which for 14 patients was as severe as the original dominant pain. After bilateral cordotomy, 7 patients (53.4%) exhibited new pain, which was located cephalad to the region rendered analgesic by cordotomy and was better controlled than the original pain. No pathological organic causes of new pain were found in any patient, and evidence of a referred pain mechanism was found in 3 patients after bilateral cordotomy. CONCLUSION: These results show that a referred pain mechanism causes increased or new pain after cordotomy in patients with bilateral pain. Nevertheless, cordotomy can still be indicated for patients with bilateral pain because postoperative pain is better controlled than the original pain.