- Email: [email protected]
Role of percutaneous cervical cordotomy in cancer pain management
Role of percutaneous cervical cordotomy in cancer pain management Matrix reference 3E00
Alireza Feizerfan FRCA JHL Antrobus FFPMRCA
Key points
Interventional techniques should be considered as adjuvant therapy alongside the World Health Organization analgesic ladder. Percutaneous cervical cordotomy (PCC) ablates the sensory pathways of the lateral spinothalamic tract and is a safe and effective technique for unilateral pain below the clavicle. PCC is particularly recommended for costo-pleural syndrome in malignant pleural mesothelioma. After successful PCC, down-titration of analgesia will be necessary.
Alireza Feizerfan FRCA Specialty Registrar in Anaesthesia South Warwickshire NHS Foundation Trust Lakin Road Warwick CV34 5BW UK JHL Antrobus FFPMRCA Consultant Anaesthesia and Pain Medicine South Warwickshire NHS Foundation Trust Lakin Road Warwick CV34 5BW UK Tel: þ44 1926 495321 Fax: þ44 1926 482613 E-mail: [email protected] (for correspondence)
23
Anatomy The lateral spinothalamic tract (LST) lies in the anterolateral quadrant of the spinal cord, carrying pain and temperature sensation from the contralateral side. Within the LST, the fibres are somatotopic; sacral fibres are located more
posteriorly while the cervical fibres are located anteriorly (Fig. 1). The LST is superficial, lying close to the lateral surface of the cord. The LST is related medially to the diaphragmatic reticulospinal tract; posteriorly to the corticospinal tract; and anteriorly to the ventral horn. The dentate ligament is an important anatomic landmark during the procedure. It marks the equator of the cord lying just posterior to the LST and is used to guide the placement of the needle for PCC. Lateral approach to the spinal cord is easiest at C1/2 and thermoablation at this level controls pain below C4 on the contralateral side. The extent of analgesia will depend on the position of the electrode within the LST and the size of the thermal lesion. Because PCC is selective for pain and temperature sensation, it achieves pain relief without numbness, preserving motor power and proprioception.
Technique Cordotomy is still performed as an open surgical procedure by laminectomy under general anaesthesia with a wake-up test intraoperatively, but most commonly a percutaneous approach is used.9 PCC uses an electrode-through-needle technique. Ideally, the depth of the lesion created should be between 4 and 5 mm to avoid encroachment on the respiratory fibres in the reticulospinal tract. The electrode is fitted with a clamp that is adjusted so that the tip of the electrode protrudes 4–5 mm beyond the end of the spinal needle. The electrode is insulated with a 2 mm active tip. The electrode is connected to a RF lesion generator, with a grounding connection to the patient to complete the circuit. The patient is positioned supine on an X-ray table with the head supported and restrained in a Rosomoff or Pounder headrest. I.V. access and monitoring are established and analgesia administered. Conscious sedation may be used. The skin entry point is located over the C1/2
doi:10.1093/bjaceaccp/mkt033 Advance Access publication 26 August, 2013 Continuing Education in Anaesthesia, Critical Care & Pain | Volume 14 Number 1 2014 & The Author [2013]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: [email protected]
Downloaded from http://ceaccp.oxfordjournals.org/ at Northeastern University Libraries on June 15, 2014
Up to 10% of adults with cancer fail to achieve adequate pain relief despite an optimized regime of systemic analgesia.
Pain control in cancer patients reduces suffering and improves the quality of life. The classic World Health Organization (WHO) analgesic ladder may be effective in controlling cancer pain in 80–90% of patients.1 In the UK, current application of the principles embodied in the WHO ladder follows a modified algorithm by which interventional techniques should be considered as adjuvant therapy alongside all steps of the analgesic ladder.2 Recent UK experience suggests that, despite optimization of systemic analgesia, 11% patients in a hospice setting were considered for interventional therapy.3 The scope of advanced pain management techniques in adult palliative care is contained within the Specialised Services National Definition Set and the full range of interventions has been reviewed elsewhere.4 This article describes the technique and application of percutaneous cervical cordotomy (PCC) in the management of intractable unilateral cancer pain. Experience of the neurological deficit resulting from tuberculous lesions of the spinal cord caused Spiller to conclude that pain could be relieved by cutting the pain pathway in the spinal cord, leading to the first open surgical cordotomy in 1905.5 Reports of open cordotomy via thoracic and cervical laminectomy continued until percutaneous techniques were described in the 1960s, initially using a radioactive needle and subsequently with radiofrequency (RF) thermocoagulation.6 A computed tomography (CT)guided technique has been described,7 but the vast majority of cordotomies performed in the UK are by percutaneous RF under fluoroscopic guidance.8
Role of percutaneous cervical cordotomy
Fig 2 Lateral view of the cervical spine following injection of Omnipaque 240. A, anterior surface of spinal cord; B, dentate ligament; C, contrast pooling in the subarachnoid space; D, spinal needle with tip impinging on dentate ligament.
intervertebral foramen on the opposite side to the pain and the area is cleansed and draped. Using local anaesthesia and repeated fluoroscopy, a 20-G spinal needle is advanced incrementally until dural puncture is confirmed by free flow of cerebrospinal fluid (CSF). The needle is directed to puncture the dura just anterior to the dentate ligament. With free flow of CSF confirmed, myelography is used to demonstrate the tip of the spinal needle lying anterior to the dentate ligament pointing at the LST (Fig. 2). The electrode is passed through the needle until the clamp engages in the hub. The lesion generator measures and displays impedance between the electrode and grounding plate. Penetration of
24
Table 1 Key stages in PCC † † † † † † † †
Supine position with Pounder or Rosamov head restraint X-ray fluoroscopy with lateral and odontoid peg views Dural puncture, lateral approach at C1/2 Myelogram demonstrating dentate ligament Spinal needle lying on/anterior to the dentate ligament Electrode-through-needle with cord puncture confirmed by impedance increase 2 Hz stimulation: motor twitch ipsilateral neck, no twitching in arm/leg 100 Hz stimulation: no tetanization, contralateral sensation of warmth or pain
Continuing Education in Anaesthesia, Critical Care & Pain j Volume 14 Number 1 2014
Downloaded from http://ceaccp.oxfordjournals.org/ at Northeastern University Libraries on June 15, 2014
Fig 1 Schematic representation of a cross-section of the spinal cord at C2. A, cortico-spinal tract; B, lateral spino-thalamic tract; C, diaphragmatic reticular fibres. Callout shows somatotopic arrangement of fibres within the lateral spino-thalamic tract.
the spinal cord is confirmed by an increase in impedance from low (electrode in CSF) to high (electrode in spinal cord). Once cord penetration is confirmed, motor and sensory stimulation is used to confirm positioning of the electrode tip within the spinal cord. Stimulation at 2 Hz should elicit twitching in the ipsilateral neck at 0.3– 0.5 V (C2 ventral horn stimulation), but should not lead to twitching in the arm or lower limb (corticospinal tract). When 2 Hz stimulation suggests that the electrode tip is a safe distance from motor tracts, stimulation at 100 Hz follows. If the electrode is in or close to the corticospinal tract, this will lead to tetanization of the muscles. In the absence of tetanization, the sensory response to 100 Hz stimulation is assessed. At this stage, the cooperation of the patient, who must report the sensory experience, is essential. Report of temperature or pain sensation on the side contralateral to the electrode, the painful side, indicates electrode placement in the LST. If the sensation is felt in the hand, the electrode is centrally placed in the LST. The interpretation of the responses to motor and sensory stimulation is crucial to the procedure. If there is any doubt as to the position of the electrode, an RF lesion should not be created. The electrode may be withdrawn, the spinal needle angled dorsally or ventrally, and the electrode reinserted with further stimulation testing. If a satisfactory position is not found within a limited number of cord punctures or a total operating time of 90 min, the procedure is best terminated. The main features of the ideal cordotomy are given in Table 1.10 With satisfactory stimulation responses, RF thermocoagulation can proceed. Sequential lesions at rising temperatures from 70 to 858C for 20– 45 s are created. During thermocoagulation, the patient is asked to raise and lower the leg and to squeeze with the hand on the same side as the electrode as a test of motor function. After each lesion, sensory testing to pinprick is used comparing symmetrical areas on the two sides. Success of the procedure will be apparent immediately, with reduced pain intensity and hypoalgesia to pinprick within the treated area. Opioid analgesia is reduced to 30 –50% of the pre-treatment dose with continuing availability of interval dosing. Further assessment and dose titration will need to continue over the following days. More rapid dose reduction may lead to a withdrawal syndrome; occasionally, the sudden reduction in pain leads to excessive sedation because of residual opioid effect.
Role of percutaneous cervical cordotomy
Indication
Contraindications The most common reason for withholding cordotomy is advanced disease with pain that prevents the patient lying flat and remaining still for the required 40 –90 min. Unfortunately, some patients are referred to late; PCC is not a rescue procedure for analgesic failure in the terminal stage of disease. Other contraindications include: abnormal coagulation, high risk of infection and severe respiratory dysfunction. Dyspnoea is common with advancing MPM; a patient with a forced vital capacity in 1 s .12 ml kg21 has sufficient respiratory reserve to undergo cordotomy.
Outcome The evidence base for PCC is small, entirely case series. Pounder reports a reduction in opioid requirement .50% for 83% patients.9 The Invasive Neurodestructive Procedures in Cancer Pain (INPiC) study intends to investigate a range of such procedures. The INPiC Table 2 INPiC consensus statements Consensus Conference on the Role of Spinothalamic Cordotomy in the Management of Mesothelioma Pain, Royal Society of Medicine, London, 10 October 2011 Statement
Consensus
Cordotomy has a place in the management of mesothelioma-related cancer pain The potential benefits of cordotomy far outweigh the risks of the procedure The evidence-base for the use of cordotomy in mesothelioma-related pain is robust To what extent, in your opinion, are patients with mesothelioma in the UK who would potentially benefit from the procedure referred for cordotomy? In your opinion, are patients with mesothelioma in the UK who would potentially benefit from cordotomy referred at the appropriate time? Cordotomy should only ever be considered for mesothelioma-related pain
Yes Yes Uncertainty They’re not
Complications It is difficult to quote definite figures for post PCC complication rates. Cordotomy is performed at a time when the disease trajectory is deteriorating, when new and adverse events attributable to the underlying pathology are to be expected. Case reports are biased towards adverse effects without reference to a denominator. It is important to relate reports of complications to the technique of cordotomy used; open cordotomy creates a more extensive lesion, whereas percutaneous thermocoagulation is more selective. One death was reported in a series of more than 600 cases.9 Headache, in a C2 distribution, is very common but usually transient. Serious complications related directly to the procedure are minimal in experienced hands.
Failure The procedure may be terminated without creating a thermal lesion if the LST is not identified with confidence, particularly regarding proximity to motor tracts: reported rates vary up to 33% depending on experience of the operator. Occasionally, a thermal lesion in the LST may not cover the affected area fully. Oedema around the lesion may resolve resulting in shrinkage of the hypoalgesic area in the early postoperative stage.
Neuropathic pain Neuropathic pain after cordotomy may manifest as mirror pain or dysaesthesia. The relief of pain on the diseased side may be accompanied by the onset of pain in a mirror distribution by an unknown mechanism. Some patients may experience dysaesthesia within the hypoalgesic area after treatment. Clinical experience suggests that, in the majority of cases, such pains are less severe and more easily controlled than the original symptom. The potential for the development of neuropathic pain in long-term survivors must be acknowledged and life expectancy considered carefully in patient selection.
Autonomic effects Horner’s syndrome is common, usually resolves and often passes unnoticed. Hypotension may occur, but is usually asymptomatic. Persistent postural hypotension is uncommon.
They’re not
Respiratory effects
No
Lesions with a depth of ,5 mm are thought to spare the reticulospinal tract. Price and colleagues13 showed no change in spirometry
Continuing Education in Anaesthesia, Critical Care & Pain j Volume 14 Number 1 2014
25
Downloaded from http://ceaccp.oxfordjournals.org/ at Northeastern University Libraries on June 15, 2014
PCC is indicated for unilateral cancer-related pain in patients with life expectancy estimated to be ,12 months. It is most strongly recommended for the relief of costo-pleural syndrome because of malignant pleural mesothelioma (MPM), but is applicable to other cancer-related pain that is unilateral and below the fourth cervical dermatome: lung cancer; breast cancer; brachial plexus pain attributable to Pancoast tumour; or unilateral leg pain. PCC has been used for bilateral cancer pain, but bilateral lesions carry a higher complication and mortality rate. Patients will be referred because they are experiencing, or are likely to experience inadequate pain control, dose-limiting sideeffects, or both despite an optimized regime of systemic analgesia with adjuvant treatment. In MPM, referral should be considered when the patient first commences strong opioids; once chest wall invasion occurs, MPM typically progresses rapidly and life-expectancy is limited to months.
pilot study examined the use of PCC specifically for the treatment of pain because of MPM.11 Results of a systematic literature review, service survey, and Delphi study were reported at a consensus conference in October 2011 (Table 2). The systematic review reports: ‘All studies demonstrated good pain relief in most patients on all pain outcome measures (global measure, pain intensity, analgesic level, total sleeping hours)’.12
Role of percutaneous cervical cordotomy
after unilateral PCC. It may be that lesions of the reticulospinal tract affect automaticity of breathing; Ondine’s curse has been reported.14
Motor effects
Conclusion PCC is a technique used to control unilateral pain in cancer patients, most importantly costo-pleural syndrome in MPM. The evidence base for the use of PCC is small, all case series, but such evidence demonstrates good pain relief in most patients. Life-threatening complications occur in ,1%, but minor side-effects are common (mirror pain, temporary weakness, and mild dysaesthesia). More robust evidence should emerge from the INPiC pilot study and the Selective Percutaneous Cordotomy Registry launched in December 2012.
Declaration of interest None declared.
References 1. Schug SA, Zech D, Dorr U. Cancer pain management according to the WHO analgesic guidelines. Pain Symptom Manage 1990; 5: 27–32
26
3. Linklater GT, Leng MEF, Tiernan EJJ et al. Pain management services in palliative care: a national survey. Palliat Med 2002; 16: 435–9 4. DeCourcy JG. Interventional techniques for cancer pain management. Clin Oncol 2011; 23: 407– 17 5. Spiller WG. The occasional clinical resemblance between caries of the vertebrae and lumbothoracic syringomyelia and the location within the spinal cord of the fibres for the sensations of pain and temperature. Univ Penn Med Bull 1905; 18: 147– 54 6. Rosomoff HL, Carroll F, Brown J, Sheptak P. Percutaneous radiofrequency cervical cordotomy: technique. J Neurosurg 1965; 23: 639– 44 7. Kanpolat Y, Akyar S, Caglar S, Unlu A, Bilgic S. CT-guided percutaneous selective cordotomy. Acta Neurochir 1993; 123: 92– 6 8. Jackson MB, Pounder D, Price C, Matthews AW, Neville E. Percutaneous cervical cordotomy for the control of pain in patients with pleural mesothelioma. Thorax 1999; 54: 238– 41 9. Williams M, Pounder D. Cordotomy. In: Hester J, Sykes N, Peat S, eds. Interventional Pain Control in Cancer Pain Management. Oxford: Oxford University Press, 2012. 10. Tasker RR, North R. Cordotomy and myelotomy. In: North RB, Levy RM, eds. Neurosurgical Management of Pain. New York: Springer, 1997 11. Makin MK, Poolman M, Leach A, Sharma M, Hugel H, Ellershaw J. The INPiC Pilot Project (Invasive Destructive Procedures in Cancer Pain): what is the role of cordotomy in mesothelioma related pain? Palliat Med 2012; 26: 545 12. Poolman M, France B, Lewis R, Hanan B, Sharma M. The use of cordotomy in mesothelioma-related pain: a systematic literature review. Palliat Med 2012; 26: 459 –60 13. Price C, Pounder D, Jackson M, Rogers P, Neville E. Respiratory function after unilateral percutaneous cervical cordotomy. J Pain Symptom Manage 2003; 25: 459– 63 14. Tranmer BI, Tucker WS, Bilbao JM. Sleep apnea following percutaneous cervical cordotomy. Can J Neurol Sci 1987; 14: 262– 7
Please see multiple choice questions 17– 20.
Continuing Education in Anaesthesia, Critical Care & Pain j Volume 14 Number 1 2014
Downloaded from http://ceaccp.oxfordjournals.org/ at Northeastern University Libraries on June 15, 2014
Ipsilateral weakness may result from oedema around the thermal lesion encroaching the corticospinal tract, resolving over hours or days. Despite finding transient weakness in 69% patients, Lahuerta reported weakness persisting at 1 month in 2%. Pounder reported lower limb weakness in 4 of 52 patients, none severe enough to prevent mobilization.9 Concern regarding damage to the corticospinal tract is reflected more in the failure rate through abstaining from a lesion than in motor weakness.
2. Eisenberg E, Marinangeli F, Birkhahn J, Paladini A, Varrassi G. Time to modify the WHO analgesic ladder? Pain Clin Updat 2005; 13: 1– 4
Alireza Feizerfan FRCA JHL Antrobus FFPMRCA
Key points
Interventional techniques should be considered as adjuvant therapy alongside the World Health Organization analgesic ladder. Percutaneous cervical cordotomy (PCC) ablates the sensory pathways of the lateral spinothalamic tract and is a safe and effective technique for unilateral pain below the clavicle. PCC is particularly recommended for costo-pleural syndrome in malignant pleural mesothelioma. After successful PCC, down-titration of analgesia will be necessary.
Alireza Feizerfan FRCA Specialty Registrar in Anaesthesia South Warwickshire NHS Foundation Trust Lakin Road Warwick CV34 5BW UK JHL Antrobus FFPMRCA Consultant Anaesthesia and Pain Medicine South Warwickshire NHS Foundation Trust Lakin Road Warwick CV34 5BW UK Tel: þ44 1926 495321 Fax: þ44 1926 482613 E-mail: [email protected] (for correspondence)
23
Anatomy The lateral spinothalamic tract (LST) lies in the anterolateral quadrant of the spinal cord, carrying pain and temperature sensation from the contralateral side. Within the LST, the fibres are somatotopic; sacral fibres are located more
posteriorly while the cervical fibres are located anteriorly (Fig. 1). The LST is superficial, lying close to the lateral surface of the cord. The LST is related medially to the diaphragmatic reticulospinal tract; posteriorly to the corticospinal tract; and anteriorly to the ventral horn. The dentate ligament is an important anatomic landmark during the procedure. It marks the equator of the cord lying just posterior to the LST and is used to guide the placement of the needle for PCC. Lateral approach to the spinal cord is easiest at C1/2 and thermoablation at this level controls pain below C4 on the contralateral side. The extent of analgesia will depend on the position of the electrode within the LST and the size of the thermal lesion. Because PCC is selective for pain and temperature sensation, it achieves pain relief without numbness, preserving motor power and proprioception.
Technique Cordotomy is still performed as an open surgical procedure by laminectomy under general anaesthesia with a wake-up test intraoperatively, but most commonly a percutaneous approach is used.9 PCC uses an electrode-through-needle technique. Ideally, the depth of the lesion created should be between 4 and 5 mm to avoid encroachment on the respiratory fibres in the reticulospinal tract. The electrode is fitted with a clamp that is adjusted so that the tip of the electrode protrudes 4–5 mm beyond the end of the spinal needle. The electrode is insulated with a 2 mm active tip. The electrode is connected to a RF lesion generator, with a grounding connection to the patient to complete the circuit. The patient is positioned supine on an X-ray table with the head supported and restrained in a Rosomoff or Pounder headrest. I.V. access and monitoring are established and analgesia administered. Conscious sedation may be used. The skin entry point is located over the C1/2
doi:10.1093/bjaceaccp/mkt033 Advance Access publication 26 August, 2013 Continuing Education in Anaesthesia, Critical Care & Pain | Volume 14 Number 1 2014 & The Author [2013]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: [email protected]
Downloaded from http://ceaccp.oxfordjournals.org/ at Northeastern University Libraries on June 15, 2014
Up to 10% of adults with cancer fail to achieve adequate pain relief despite an optimized regime of systemic analgesia.
Pain control in cancer patients reduces suffering and improves the quality of life. The classic World Health Organization (WHO) analgesic ladder may be effective in controlling cancer pain in 80–90% of patients.1 In the UK, current application of the principles embodied in the WHO ladder follows a modified algorithm by which interventional techniques should be considered as adjuvant therapy alongside all steps of the analgesic ladder.2 Recent UK experience suggests that, despite optimization of systemic analgesia, 11% patients in a hospice setting were considered for interventional therapy.3 The scope of advanced pain management techniques in adult palliative care is contained within the Specialised Services National Definition Set and the full range of interventions has been reviewed elsewhere.4 This article describes the technique and application of percutaneous cervical cordotomy (PCC) in the management of intractable unilateral cancer pain. Experience of the neurological deficit resulting from tuberculous lesions of the spinal cord caused Spiller to conclude that pain could be relieved by cutting the pain pathway in the spinal cord, leading to the first open surgical cordotomy in 1905.5 Reports of open cordotomy via thoracic and cervical laminectomy continued until percutaneous techniques were described in the 1960s, initially using a radioactive needle and subsequently with radiofrequency (RF) thermocoagulation.6 A computed tomography (CT)guided technique has been described,7 but the vast majority of cordotomies performed in the UK are by percutaneous RF under fluoroscopic guidance.8
Role of percutaneous cervical cordotomy
Fig 2 Lateral view of the cervical spine following injection of Omnipaque 240. A, anterior surface of spinal cord; B, dentate ligament; C, contrast pooling in the subarachnoid space; D, spinal needle with tip impinging on dentate ligament.
intervertebral foramen on the opposite side to the pain and the area is cleansed and draped. Using local anaesthesia and repeated fluoroscopy, a 20-G spinal needle is advanced incrementally until dural puncture is confirmed by free flow of cerebrospinal fluid (CSF). The needle is directed to puncture the dura just anterior to the dentate ligament. With free flow of CSF confirmed, myelography is used to demonstrate the tip of the spinal needle lying anterior to the dentate ligament pointing at the LST (Fig. 2). The electrode is passed through the needle until the clamp engages in the hub. The lesion generator measures and displays impedance between the electrode and grounding plate. Penetration of
24
Table 1 Key stages in PCC † † † † † † † †
Supine position with Pounder or Rosamov head restraint X-ray fluoroscopy with lateral and odontoid peg views Dural puncture, lateral approach at C1/2 Myelogram demonstrating dentate ligament Spinal needle lying on/anterior to the dentate ligament Electrode-through-needle with cord puncture confirmed by impedance increase 2 Hz stimulation: motor twitch ipsilateral neck, no twitching in arm/leg 100 Hz stimulation: no tetanization, contralateral sensation of warmth or pain
Continuing Education in Anaesthesia, Critical Care & Pain j Volume 14 Number 1 2014
Downloaded from http://ceaccp.oxfordjournals.org/ at Northeastern University Libraries on June 15, 2014
Fig 1 Schematic representation of a cross-section of the spinal cord at C2. A, cortico-spinal tract; B, lateral spino-thalamic tract; C, diaphragmatic reticular fibres. Callout shows somatotopic arrangement of fibres within the lateral spino-thalamic tract.
the spinal cord is confirmed by an increase in impedance from low (electrode in CSF) to high (electrode in spinal cord). Once cord penetration is confirmed, motor and sensory stimulation is used to confirm positioning of the electrode tip within the spinal cord. Stimulation at 2 Hz should elicit twitching in the ipsilateral neck at 0.3– 0.5 V (C2 ventral horn stimulation), but should not lead to twitching in the arm or lower limb (corticospinal tract). When 2 Hz stimulation suggests that the electrode tip is a safe distance from motor tracts, stimulation at 100 Hz follows. If the electrode is in or close to the corticospinal tract, this will lead to tetanization of the muscles. In the absence of tetanization, the sensory response to 100 Hz stimulation is assessed. At this stage, the cooperation of the patient, who must report the sensory experience, is essential. Report of temperature or pain sensation on the side contralateral to the electrode, the painful side, indicates electrode placement in the LST. If the sensation is felt in the hand, the electrode is centrally placed in the LST. The interpretation of the responses to motor and sensory stimulation is crucial to the procedure. If there is any doubt as to the position of the electrode, an RF lesion should not be created. The electrode may be withdrawn, the spinal needle angled dorsally or ventrally, and the electrode reinserted with further stimulation testing. If a satisfactory position is not found within a limited number of cord punctures or a total operating time of 90 min, the procedure is best terminated. The main features of the ideal cordotomy are given in Table 1.10 With satisfactory stimulation responses, RF thermocoagulation can proceed. Sequential lesions at rising temperatures from 70 to 858C for 20– 45 s are created. During thermocoagulation, the patient is asked to raise and lower the leg and to squeeze with the hand on the same side as the electrode as a test of motor function. After each lesion, sensory testing to pinprick is used comparing symmetrical areas on the two sides. Success of the procedure will be apparent immediately, with reduced pain intensity and hypoalgesia to pinprick within the treated area. Opioid analgesia is reduced to 30 –50% of the pre-treatment dose with continuing availability of interval dosing. Further assessment and dose titration will need to continue over the following days. More rapid dose reduction may lead to a withdrawal syndrome; occasionally, the sudden reduction in pain leads to excessive sedation because of residual opioid effect.
Role of percutaneous cervical cordotomy
Indication
Contraindications The most common reason for withholding cordotomy is advanced disease with pain that prevents the patient lying flat and remaining still for the required 40 –90 min. Unfortunately, some patients are referred to late; PCC is not a rescue procedure for analgesic failure in the terminal stage of disease. Other contraindications include: abnormal coagulation, high risk of infection and severe respiratory dysfunction. Dyspnoea is common with advancing MPM; a patient with a forced vital capacity in 1 s .12 ml kg21 has sufficient respiratory reserve to undergo cordotomy.
Outcome The evidence base for PCC is small, entirely case series. Pounder reports a reduction in opioid requirement .50% for 83% patients.9 The Invasive Neurodestructive Procedures in Cancer Pain (INPiC) study intends to investigate a range of such procedures. The INPiC Table 2 INPiC consensus statements Consensus Conference on the Role of Spinothalamic Cordotomy in the Management of Mesothelioma Pain, Royal Society of Medicine, London, 10 October 2011 Statement
Consensus
Cordotomy has a place in the management of mesothelioma-related cancer pain The potential benefits of cordotomy far outweigh the risks of the procedure The evidence-base for the use of cordotomy in mesothelioma-related pain is robust To what extent, in your opinion, are patients with mesothelioma in the UK who would potentially benefit from the procedure referred for cordotomy? In your opinion, are patients with mesothelioma in the UK who would potentially benefit from cordotomy referred at the appropriate time? Cordotomy should only ever be considered for mesothelioma-related pain
Yes Yes Uncertainty They’re not
Complications It is difficult to quote definite figures for post PCC complication rates. Cordotomy is performed at a time when the disease trajectory is deteriorating, when new and adverse events attributable to the underlying pathology are to be expected. Case reports are biased towards adverse effects without reference to a denominator. It is important to relate reports of complications to the technique of cordotomy used; open cordotomy creates a more extensive lesion, whereas percutaneous thermocoagulation is more selective. One death was reported in a series of more than 600 cases.9 Headache, in a C2 distribution, is very common but usually transient. Serious complications related directly to the procedure are minimal in experienced hands.
Failure The procedure may be terminated without creating a thermal lesion if the LST is not identified with confidence, particularly regarding proximity to motor tracts: reported rates vary up to 33% depending on experience of the operator. Occasionally, a thermal lesion in the LST may not cover the affected area fully. Oedema around the lesion may resolve resulting in shrinkage of the hypoalgesic area in the early postoperative stage.
Neuropathic pain Neuropathic pain after cordotomy may manifest as mirror pain or dysaesthesia. The relief of pain on the diseased side may be accompanied by the onset of pain in a mirror distribution by an unknown mechanism. Some patients may experience dysaesthesia within the hypoalgesic area after treatment. Clinical experience suggests that, in the majority of cases, such pains are less severe and more easily controlled than the original symptom. The potential for the development of neuropathic pain in long-term survivors must be acknowledged and life expectancy considered carefully in patient selection.
Autonomic effects Horner’s syndrome is common, usually resolves and often passes unnoticed. Hypotension may occur, but is usually asymptomatic. Persistent postural hypotension is uncommon.
They’re not
Respiratory effects
No
Lesions with a depth of ,5 mm are thought to spare the reticulospinal tract. Price and colleagues13 showed no change in spirometry
Continuing Education in Anaesthesia, Critical Care & Pain j Volume 14 Number 1 2014
25
Downloaded from http://ceaccp.oxfordjournals.org/ at Northeastern University Libraries on June 15, 2014
PCC is indicated for unilateral cancer-related pain in patients with life expectancy estimated to be ,12 months. It is most strongly recommended for the relief of costo-pleural syndrome because of malignant pleural mesothelioma (MPM), but is applicable to other cancer-related pain that is unilateral and below the fourth cervical dermatome: lung cancer; breast cancer; brachial plexus pain attributable to Pancoast tumour; or unilateral leg pain. PCC has been used for bilateral cancer pain, but bilateral lesions carry a higher complication and mortality rate. Patients will be referred because they are experiencing, or are likely to experience inadequate pain control, dose-limiting sideeffects, or both despite an optimized regime of systemic analgesia with adjuvant treatment. In MPM, referral should be considered when the patient first commences strong opioids; once chest wall invasion occurs, MPM typically progresses rapidly and life-expectancy is limited to months.
pilot study examined the use of PCC specifically for the treatment of pain because of MPM.11 Results of a systematic literature review, service survey, and Delphi study were reported at a consensus conference in October 2011 (Table 2). The systematic review reports: ‘All studies demonstrated good pain relief in most patients on all pain outcome measures (global measure, pain intensity, analgesic level, total sleeping hours)’.12
Role of percutaneous cervical cordotomy
after unilateral PCC. It may be that lesions of the reticulospinal tract affect automaticity of breathing; Ondine’s curse has been reported.14
Motor effects
Conclusion PCC is a technique used to control unilateral pain in cancer patients, most importantly costo-pleural syndrome in MPM. The evidence base for the use of PCC is small, all case series, but such evidence demonstrates good pain relief in most patients. Life-threatening complications occur in ,1%, but minor side-effects are common (mirror pain, temporary weakness, and mild dysaesthesia). More robust evidence should emerge from the INPiC pilot study and the Selective Percutaneous Cordotomy Registry launched in December 2012.
Declaration of interest None declared.
References 1. Schug SA, Zech D, Dorr U. Cancer pain management according to the WHO analgesic guidelines. Pain Symptom Manage 1990; 5: 27–32
26
3. Linklater GT, Leng MEF, Tiernan EJJ et al. Pain management services in palliative care: a national survey. Palliat Med 2002; 16: 435–9 4. DeCourcy JG. Interventional techniques for cancer pain management. Clin Oncol 2011; 23: 407– 17 5. Spiller WG. The occasional clinical resemblance between caries of the vertebrae and lumbothoracic syringomyelia and the location within the spinal cord of the fibres for the sensations of pain and temperature. Univ Penn Med Bull 1905; 18: 147– 54 6. Rosomoff HL, Carroll F, Brown J, Sheptak P. Percutaneous radiofrequency cervical cordotomy: technique. J Neurosurg 1965; 23: 639– 44 7. Kanpolat Y, Akyar S, Caglar S, Unlu A, Bilgic S. CT-guided percutaneous selective cordotomy. Acta Neurochir 1993; 123: 92– 6 8. Jackson MB, Pounder D, Price C, Matthews AW, Neville E. Percutaneous cervical cordotomy for the control of pain in patients with pleural mesothelioma. Thorax 1999; 54: 238– 41 9. Williams M, Pounder D. Cordotomy. In: Hester J, Sykes N, Peat S, eds. Interventional Pain Control in Cancer Pain Management. Oxford: Oxford University Press, 2012. 10. Tasker RR, North R. Cordotomy and myelotomy. In: North RB, Levy RM, eds. Neurosurgical Management of Pain. New York: Springer, 1997 11. Makin MK, Poolman M, Leach A, Sharma M, Hugel H, Ellershaw J. The INPiC Pilot Project (Invasive Destructive Procedures in Cancer Pain): what is the role of cordotomy in mesothelioma related pain? Palliat Med 2012; 26: 545 12. Poolman M, France B, Lewis R, Hanan B, Sharma M. The use of cordotomy in mesothelioma-related pain: a systematic literature review. Palliat Med 2012; 26: 459 –60 13. Price C, Pounder D, Jackson M, Rogers P, Neville E. Respiratory function after unilateral percutaneous cervical cordotomy. J Pain Symptom Manage 2003; 25: 459– 63 14. Tranmer BI, Tucker WS, Bilbao JM. Sleep apnea following percutaneous cervical cordotomy. Can J Neurol Sci 1987; 14: 262– 7
Please see multiple choice questions 17– 20.
Continuing Education in Anaesthesia, Critical Care & Pain j Volume 14 Number 1 2014
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Ipsilateral weakness may result from oedema around the thermal lesion encroaching the corticospinal tract, resolving over hours or days. Despite finding transient weakness in 69% patients, Lahuerta reported weakness persisting at 1 month in 2%. Pounder reported lower limb weakness in 4 of 52 patients, none severe enough to prevent mobilization.9 Concern regarding damage to the corticospinal tract is reflected more in the failure rate through abstaining from a lesion than in motor weakness.
2. Eisenberg E, Marinangeli F, Birkhahn J, Paladini A, Varrassi G. Time to modify the WHO analgesic ladder? Pain Clin Updat 2005; 13: 1– 4