Postoperative Peripheral Nerve Stimulation for Management of Post-amputation Pain

Study Overview
=================
Brief Summary
-----------------
Limb loss is frequently associated with postamputation pain that can be challenging to treat and often involves opioids. Advances in the field of neuromodulation has led to development of an intentionally reversible percutaneous peripheral nerve stimulation (PNS) system that has had promising results when treating chronic postamputation pain. PNS may offer sustained pain relief even after the treatment period has ended. Currently, there is no convincing evidence regarding the role of PNS in the acute postoperative period, which may be a critical time to control pain as those with higher pain appear to be at higher risk for developing persistent post-procedural pain. The investigators of this study aim to evaluate the feasibility and effects of PNS in the acute postoperative period and determine the feasibility of completing a randomized controlled treatment outcome study.

Detailed Description
-----------------
16 patients with new nontraumatic transfemoral or transtibial amputation will be enrolled in the study Having met inclusion criteria, the patients will be randomized to experimental or control groups Patients in the experimental group undergo placement of PNS leads within 7 days of amputation surgery Patients in both groups will be treated with standard pharmacologic and nonpharmacologic pain therapies and evaluated weekly for 8 weeks, then at 3, 6, and 12 months postamputation

Official Title
-----------------
Effects of Postoperative Percutaneous Peripheral Nerve Stimulation on Acute and Chronic Amputation Pain

Conditions
-----------------
Phantom Limb Pain, Postoperative Pain, Neuroma, Acute Pain, Chronic Pain, Residual Limbs, Amputation

Intervention / Treatment
-----------------
* Device: Peripheral nerve stimulation
* Other: Standard Medical Therapy


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Nontraumatic transfemoral (above-the-knee) or transtibial (below-the-knee) amputation Presence of postamputation pain rated at least 4 or more Exclusion Criteria: Beck Depression Inventory score greater than 20 Systemic infection Immunocompromised or taking immunosuppressive medications Implanted electronic device Pregnancy Previous allergy to skin contact materials and/or anesthetic agent Altered mental status Inability to provide informed consent

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group 1<br>Standard medical therapy and 30 to 60 days of peripheral nerve stimulation starting within 7 days after surgery | Device: Peripheral nerve stimulation<br>* Up to 60 days of peripheral nerve stimulation<br>Other: Standard Medical Therapy<br>* Medications, physical therapy, or other pain treatments<br>|
| Active Comparator: Group 2<br>Standard medical therapy only | Other: Standard Medical Therapy<br>* Medications, physical therapy, or other pain treatments<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Average Phantom Limb Pain (PLP) Score | Using the Brief Pain Inventory-Short Form (BPI-SF) questionnaire, subjects were asked to rate their PLP over the past 24 hours on a scale of 0=no pain to 10=worst pain they have ever experienced. A lower score is better. Data from Weeks 1-4 and Weeks 5-8 were averaged to obtain a numerical score for these time points. | Baseline, Weeks 1-4, Weeks 5-8, and Month 3. | 
| Average Residual Limb Pain (RLP) Score | Using the Brief Pain Inventory-Short Form (BPI-SF) questionnaire, subjects were asked to rate their RLP over the past 24 hours on a scale of 0=no pain to 10=worst pain they have ever experienced. A lower score is better. Data from Weeks 1-4 and Weeks 5-8 were averaged to obtain a numerical score for these time points. | Baseline, Weeks 1-4, Weeks 5-8, and Month 3 | 
| Worst Phantom Limb Pain (PLP) Score | Using the Brief Pain Inventory-Short Form (BPI-SF) questionnaire, subjects were asked to rate their PLP over the past 24 hours on a scale of 0=no pain to 10=worst pain they have ever experienced. A lower score is better. Data from Weeks 1-4 and Weeks 5-8 were averaged to obtain a numerical score for these time points. | Baseline, Weeks 1-4, 5-8, and Month 3 | 
| Worst Residual Limb Pain (RLP) Score | Using the Brief Pain Inventory-Short Form (BPI-SF) questionnaire, subjects were asked to rate their RLP over the past 24 hours on a scale of 0=no pain to 10=worst pain they have ever experienced. A lower score is better. Data from Weeks 1-4 and Weeks 5-8 were averaged to obtain a numerical score for these time points. | Baseline, Weeks 1-4, Weeks 5-8, and Month 3 | 
| Best Phantom Limb Pain (PLP) Score | Using the Brief Pain Inventory-Short Form (BPI-SF) questionnaire, subjects were asked to rate their PLP over the past 24 hours on a scale of 0=no pain to 10=worst pain they have ever experienced. A lower score is better. Data from Weeks 1-4 and Weeks 5-8 were averaged to obtain a numerical score for these time points. | Baseline, Weeks 1-4, Weeks 5-8, and Month 3 | 
| Best Residual Limb Pain (RLP) Score | Using the Brief Pain Inventory-Short Form (BPI-SF) questionnaire, subjects were asked to rate their RLP over the past 24 hours on a scale of 0=no pain to 10=worst pain they have ever experienced. A lower score is better. Data from Weeks 1-4 and Weeks 5-8 were averaged to obtain a numerical score for these time points. | Baseline, Weeks 1-4, Weeks 5-8, and Month 3 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number Taking Opioids | The number of subjects prescribed any opioid medication and any dose. Data from Weeks 1-4 and Weeks 5-8 were averaged to obtain a numerical score for these time points. | Preop, Hospital Discharge, Weeks 1-4, Weeks 5-8, Week 12 | 
| Average Oral Morphine Equivalents (OME) | Opioid consumption (daily OME) over time was collected for all subjects. | Preoperative, Hospital discharge, Weeks 1-4, Weeks 5-8, and Week 12 | 
| Functional Independence Measure (FIM) Scores | FIM mobility subscores were recorded by a physical therapist to measure the ability to walk, use a wheelchair, transfer to tub/shower, transfer to toilet, and mobility in bed, chair, and wheelchair. Scores range from 1 = subject requires total assistance for the task to 7 = complete independence. A higher score is better. | Preoperative, Week 4, and Week 8 | 
| Pain Interference | Using the Brief Pain Inventory-Short Form (BPI-SF) questionnaire, subjects were asked to rate how much pain has interfered with daily activities over the past 24 hours on a scale of 0 = no interference to 10 = completely interferes with activities. A lower score is better. | Baseline, Weeks 4, 8, and 12 | 
| Patient Global Impression of Change (PGIC) | Self-report measure PGIC reflects a patient's belief about the efficacy of treatment. PGIC is a 7 point scale depicting a patient's rating of overall improvement. Patients rate their change as 1 = very much improved, 2 = much improved, 3 = minimally improved, 4 = no change, 5 = minimally worse, 6 = much worse, or 7 = very much worse. A lower score is better. | Weeks 4, 8, and 12 | 
| Pain Catastrophizing Scale (PCS) | Pain catastrophizing is the tendency to magnify the threat value of a pain stimulus and to feel helpless in the presence of pain. This is further characterized by the inability to prevent or inhibit pain-related thoughts surrounding a painful event. Pain catastrophizing affects how individuals experience pain. The PCS is a 13-item inventory of statements in which the subject is asked to rate the degree to which they agree, on a scale of 0 = not at all to 4 = all the time. The responses for each item are added for a total PCS score (range 0-52). A lower score is better. | Baseline, Weeks 4, 8, and 12 | 
| Pain Disability Index (PDI) | The PDI is designed to measure the degree to which aspects of life are disrupted by chronic pain. The impact of pain on various aspects of life (e.g. family/home responsibilities, recreation, social activity, occupation, sexual behavior, self-care, and life-support activities) are recorded on a 10-point scale from 0 = no disability to 10 = worst disability. The sum of scores is recorded for a total PDI score (range 0-70). A lower score is better. | Weeks 4, Week 8, and Week 12 | 
| 30-day Readmission Rate | Percent of Group that was readmitted to the hospital within 30 days following hospital discharge. | 30 days from hospital discharge | 
| Hospital Length of Stay (LOS) | Hospital LOS was calculated from day of surgery to day of discharge from inpatient hospital ward to rehabilitation facility. | Number of days from surgery to discharge | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Neurostimulation, Peripheral nerve stimulation