Cryoablation for Phantom Limb Pain

Study Overview
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Brief Summary
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The purpose of this study is to determine if treatment with percutaneous cryoablation yields significant differences in the evaluative criteria of Phantom Limb Syndrome (PLS).

Detailed Description
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This study aims to treat Phantom Limb Syndrome (PLS) with cryoablation of the remaining nerve stumps. The rationale is that because the pain in PLS follows the known distribution of nerves, and because the amputated nerves are known to undergo changes after the surgery that may lead to excessive firing, that interruption of the nerve impulses will reduce patient pain.

Official Title
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Percutaneous Image Guided Cryoablation for the Treatment of Refractory Phantom Limb Pain

Conditions
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Phantom Limb Syndrome

Intervention / Treatment
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* Procedure: Cryoablation
* Device: 17g Galil Medical Ice Sphere cryoablation needle


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects are status post (s/p) amputation of an upper or lower limb. That is, the amputation is not congenital. Refractory pain symptoms, following tissue healing(postoperatively, or post injury) are related to amputation as determined by referring physician and investigator, to include: stump pain, phantom pain, unpleasant phantom sensations, and/or undesirable and/or life-limiting kinesthetic sensations. The character, frequency, location, description, and exacerbation or relieving elements will be recorded. Patients will be questioned as to the location of their sensation, be it pain, movement, burning, tingling, or other. The location of their pain will be correlated with the corresponding proximal nerve stump. Positive anesthetic/steroid block, as performed under CT guidance in an analogous fashion to the cryoablation procedure. Absence of infection Absence of coagulopathy Ability and willingness of patient to provide written informed consent Exclusion Criteria: Active infection Underlying congenital segmentation or other spinal anomalies that result in differential nerve root pressures Significant spinal stenosis interpreted as severe on any cross sectional imaging study Pregnant or planning to become pregnant Immunosuppression History or laboratory results indicative of any significant cardiac, endocrine, hematologic, hepatic, immunologic, infectious, metabolic, urologic, pulmonary, gastrointestinal, dermatologic, psychiatric, renal, neoplastic, or other disorder that in the opinion of the Principal Investigator would preclude the safe performance of cryoablation. Uncorrectable coagulopathies Concurrent participation in another investigational trial involving systemic administration of agents or within the previous 30 days. Have undergone a previous surgical intervention - post amputation - that may have altered the target nerve.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

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: Supportive Care
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cryoablation<br>Amputee subjects experiencing phantom limb syndrome (PLS) will receive cryoablation | Procedure: Cryoablation<br>* Subjects who respond to lidocaine nerve block will undergo CT guided cryoablation of the affected nerve stump with a 17g Galil Medical Ice Sphere cryoablation needle.<br>* Other names: Cryosurgery;Device: 17g Galil Medical Ice Sphere cryoablation needle<br>* Under CT guidance, the corresponding nerve will be targeted with a 17g probe. Two freeze-thaw cycles will be undertaken. The probe will be removed and a final scan obtained.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Feasibility of cryoablation, defined by number of participants, in which cryoablation was performed successfully | Feasibility, defined by number of participants, in which cryoablation was performed successfully | Post-Cryoablation | 
| Safety of cryoablation procedure, measured by the number of subjects that had cryoablation procedure events (CPEs). | Safety is measured by the number of subjects that had cryoablation procedure events (CPEs). CPEs are device- or procedure-related serious adverse events (SAE) or adverse events (AE) categorized as clinical signs or symptoms of infection (fever), hemorrhage (pain, imaging changes), nerve pain worsening, or toxicity of any kind (confusion, seizure). | 56 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in pain scores on visual analogue scale (VAS ) | Change in pain score will be calculated by subtracting the day 56 pain score from the baseline pain score.The pain scores are on a continuous visual analogue scale of 0 to 100 mm. 0 mm = no pain and 100 mm = worst possible pain. The VAS is scored simply by measuring the distance, in mm, from the patient's mark to one of the ends of the line. | Baseline, day 56 | 
| Change in quality of life, measured using Roland-Morris Disability Questionnaire (RDQ) | Quality of life will be measured using Roland-Morris Disability Questionnaire (RDQ); it is a validated measure of physical disability due to low back pain.The best score is 0 (no disability) and worst is 24 (maximum disability). | Baseline, day 56 |