Radiofrequency Thoracic Sympathectomy for Chronic Postmastectomy Pain; Randomized Placebo Controlled Study

Study Overview
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Brief Summary
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Postmastectomy pain syndrome (PMPS) is a neuropathic pain that can follow surgical treatment for breast cancer, The antineuropathic medications (antidepressants and anticonvulsants) are disappointing and have low success rate. Continues Radiofrequency lesioning has been reported as treatment for several chronic pain conditions.The concept that the clinical effect of RF was caused by formation of heat had not been challenged. Thermocoagulation of nerve fibers would interfere with the conduction of nociceptive stimuli and pain would be relived. Thoracic sympathectomy has been done for many painful conditions that includes complex regional pain syndrome .It offers the benefit over stellate ganglion block as it blocks the Kuntz fibers that connect to the brachial plexus roots without passing through stellate ganglion.

Detailed Description
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Postmastectomy pain syndrome (PMPS) is a neuropathic pain that can follow surgical treatment for breast cancer including radical mastectomy, modified radical mastectomy,and segmental mastectomy (lumpectomy) . The pain is distributed in the anterior chest, axilla, and medial and posterior parts of the arm . This pain can be sufficiently severe enough to interfere with sleep and performance of daily activities. Patients may develop an immobilized arm, which can lead to severe lymph edema, frozen shoulder syndrome, and complex regional pain syndrome. PMPS can result from surgical damage to the intercostobrachial nerve( the lateral cutaneous branch of the second intercostal nerve) that is often resected at mastectomy . The etiology of persistent pain after mastectomy is unclear, although it is likely multifactorial and may be partially neuropathic in nature . Previous reports of PMPS have suggested a limited number of potential risk factors, which are inconsistent among studies . While surgical factors, including more extensive surgery (mastectomy), axillary lymphnode dissection, and reconstruction have been postulated as important risk factors for chronic pain, many studies do not support this association. Adjuvant treatment, such as radiation, chemotherapy, and hormonal therapy, has also been occasionally associated with persistent pain . Among demographic factors, younger age correlates with increased incidence of persistent pain in some studies but not others . The antineuropathic medications (antidepressants and anticonvulsants) are disappointing and have low success rate, also have multiple drawbacks , specifically excessive sedation that affects daily life activities of those patients . Radiofrequency has been used for interruption of the sympathetic chain to treat intractable pain in the sacral pelvic region or for management of visceral pain and on complex regional pain syndrome. Radiofrequency has the advantage over surgical resection , in that it is more selective and may cause fewer complications. Thoracic sympathectomy has been done for many painful conditions that includes complex regional pain syndrome , neuropathic pain of upper limb and it has been done for vasospastic diseases such as Raynaud's phenomenon it offers the benefit over stellate ganglion block as it blocks the Kuntz fibers that connect to the brachial plexus roots without passing through stellate ganglion .

Official Title
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Radiofrequency Thoracic Sympathectomy for Chronic Postmastectomy Pain; Randomized Placebo Controlled Study

Conditions
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Post-Mastectomy Chronic Pain Syndrome

Intervention / Treatment
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* Procedure: radiofrequency thoracic sympathectomy
* Drug: pregabalin ,tramadol,and tricyclic antidepressants


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with chronic post-mastectomy pain for at least 6 month post-operative Patients with VAS ≥ 5 Patients on pregabalin dose ≥ 150 mg daily Patients treated with more than one line of anti-neuropathic drugs [e.g. pregabalin+(tricyclic antidepressants or selective serotonin reuptake inhibitors ) or pregabalin+ tramadole] Lymphedema of the upper limb Exclusion Criteria: Patient refusal Coagulopathy Chest and back deformity hindering procedure impossible Infection at the introduction site of the needle
Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: interventional group<br>patients will receive Radiofrequency thoracic sympathectomy then will receive pregabalin ,tramadol,and tricyclic antidepressants | Procedure: radiofrequency thoracic sympathectomy<br>* Under fluoroscopic guidance thoracic sympathectomy will be done as follow antroposterior view of upper thoracic vertebrae ,cephalo-caudal adjustment of C - arm until aliment of endplates of T2 and T3 oblique view 20 degree under tunnel view RF 10cm 20G 1mm active tip needle is introduced intimately related to vertebral margin the depth of the needle will be determined under lateral fluoroscopic view the needle is advanced step by step hugging the lateral vertebra l margin until the tip of the needle situated at the middle of the vertebral body . RF lesion 2min 80c will be done and needle is rotated 90 degree on both sides and another two lesions will be done at the end of the procedure 2ml of lidocaine and 20mg of triamcinolone will be injected at each level Post procedure analgesic protocol consisted of either increase or decrease, according to intensity of pain by 50 mg pregabalin and 50 mg tramadole and 25 mg tryptazole, individualized for each patient.<br>Drug: pregabalin ,tramadol,and tricyclic antidepressants<br>* patient will receive anti neuropathic medications<br>|
| Active Comparator: control group<br>patients will receive pregabalin ,tramadol,and tricyclic antidepressants | Drug: pregabalin ,tramadol,and tricyclic antidepressants<br>* patient will receive anti neuropathic medications<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The intensity of pain | The intensity of pain measured by visual analogue score | up to 3 months after the procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The changes in analgesics consumption | The changes in analgesics consumption | 1 month, 2 month and 3 month post-procedure | 
| The changes in mid-arm circumference | The changes in mid-arm circumference | 1 month post- procedure | 
| The changes in post-menopausal hot flashes if it was a pre-procedure complaint | The changes in post-menopausal hot flashes if it was a pre-procedure complaint | 3 month post- procedure |