Focused Ultrasound Treatment of Stump Neuromas for the Relief of Chronic Post-Amputation Neuropathic Pain

AIM: To provide initial information on the efficacy (pain reduction) and safety of focused ultrasound surgery for the ablation of stump neuromas in amputees with chronic neuropathic pain. PARTICIPANTS: The study will include 10 amputees (men/women age \>18 years old) with chronic (\>3 months) phantom/residual limb pain (NPS ≥ 4). DESIGN: Patients potentially qualifying for the study will be offered an Informed Consent to sign prior to further evaluation. Those who accept will sign the informed consent, complete study questionnaires and be evaluated in terms of inclusion/exclusion criteria. Specifically, a complete medical history will be obtained to determine the patient's general health status, current symptoms, frequency and dosage of their current analgesic intake etc. Baseline pain scores will be established. If not performed within six months prior to the evaluation, a contrast MRI of the stump will be performed. Patients not meeting the study criteria will be exited from the study as screen failures and not be included in analyses. All qualifying patients will complete a baseline MRI exam on treatment day. Any patient not meeting study criteria at Imaging will be exited as screen failures. After completion of the MRI exam, qualifying patients will proceed to the ExAblate treatment. These patients will then be followed for 6-months post-ExAblate treatment; the patients will complete study follow-up questionnaires at 1, 3 days, 1 and 2 weeks, and 1, 3 and 6 months after treatments. Follow-up visits will take place 1 week and 1, 3 and 6 months after treatment to assess their pain status, their quality of life and safety. Data regarding dosage and frequency of analgesic intake for the management of post amputation NP will be collected. Relevant cost data will be collected in order to enable an assessment of the total cost of the procedure.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

1. Men and women amputees, aged 18 and older
2. Patients who are able and willing to give consent and able to attend all study visits
3. Patients who are suffering from post-amputation phantom/residual limb pain for at least 3 months
4. Patient with average pain intensity on a 0-10 numerical pain scale (NPS) ≥ 4 during a 3 days period prior to enrollment irrespective of medication use
5. Patient whose targeted (treated) lesion is deeper than 10-mm from the skin
6. Targeted (treated) neuroma is clearly visible by non-contrast MRI, and ExAblate MRgFUS device accessible

Exclusion Criteria:

1. Patients with any acute or unstable medical condition (e.g., infection, cardiac condition, uncontrolled diabetes mellitus, uncontrolled hypertension) that is expected to hinder them from completing this study
2. Patients with standard contraindications for MR imaging such as non-MRI compatible implanted metallic devices including cardiac pacemakers, size limitations (weight \>250 pounds (113kg), etc.
3. Known intolerance or allergies to the MRI contrast agent (e.g. Gadolinium or Magnevist) including advanced kidney disease
4. Individuals who are not able or willing to tolerate the required prolonged stationary position during treatment (approximately 3 hrs.)
5. Are participating or have participated in another clinical trial in the last 30 days
6. Patients with persistent undistinguishable pain (pain source unidentifiable)
7. Patients whose neuroma is \< 10-mm from the skin, blood vessels or bone
8. Patients with more than three neuromas in the affected limb
9. Targeted (treated) neuroma is NOT visible by non-contrast MRI
10. Targeted neuroma is not accessible to ExAblate due to scar tissue or any other reason