Failed Back Surgery Syndrome
Conditions
Brief summary
The purpose of this study is to compare the effectiveness of peripheral nerve stimulation utilizing a subcutaneous lead implant technique (SQS) plus optimized medical management (OMM) versus OMM alone in patients suffering from back pain due to Failed Back Surgery Syndrome (FBSS).
Interventions
DEVICEsubcutaneous nerve stimulation
subcutaneous nerve stimulation plus optimized medical management
Optimized medical management
Sponsors
MedtronicNeuro
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. Provides written Patient Informed Consent/Patient Information Sheet prior to study-related activities being conducted 2. ≥ 18 years of age at time of informed consent 3. Willing and available to attend visits as scheduled and to comply with the study protocol 4. Willing and able to undergo assessments as part of the evaluation for eligibility and endpoints 5. Willing and able to use the external neurostimulator, recharging equipment (if applicable), and patient programmer per the schedule required by the protocol 6. Diagnosed with FBSS (i.e.): * Has had persistent pain for 6 months following most recent anatomically correct, successful surgery AND * There are no further therapeutic surgical options available as assessed by appropriate investigation 7. Back pain is considered intractable and has been adequately treated (failed an appropriate trial of at least 3 different classes of back pain treatments (pharmaceutical and/or non-pharmaceutical)) 8. Is an appropriate implant candidate for the SQS system
Exclusion criteria
1. Has been or is currently being treated with spinal cord stimulation, subcutaneous nerve stimulation, peripheral nerve stimulation or an implantable intrathecal drug delivery system 2. Evidence of an active disruptive psychiatric disorder that is significant enough to impact the perception of pain, compliance to intervention and/or ability to evaluate treatment outcome, as determined by the investigator 3. Has a pain condition unrelated to FBSS that is severe enough to overshadow the FBSS pain in the opinion of the investigator 4. Spinal instability or anatomic compression that requires further surgery 5. Spinal fusion at more than 3 vertebral levels 6. Currently enrolled in or plans to enroll in any concurrent drug and/or device study that may confound the results of this study 7. Allergic or has shown hypersensitivity to any materials of the device system which come in contact with the body 8. History of coagulation disorder or lupus erythematosus 9. Involved in current litigation regarding back pain
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Effectiveness of Treatment on Reduction of Back Pain Intensity | 9 months | Percentage of participants who responded to the treatment, where response was defined as ≥ 50% reduction in back pain intensity as measured by Visual Analog Scale from baseline to the 9-month follow-up visit. Pain intensity was measured by a 100 mm Visual Analog Scale, with 0 representing no pain and 100 representing the worst pain imaginable. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Average Change in Back Pain Intensity | 6 and 9 months | Average change in back pain intensity from baseline to the 6 and 9-month follow-up visits. Pain intensity was measured by a 100 mm Visual Analog Scale, with 0 representing no pain and 100 representing the worst pain imaginable. A reduction in average pain score is indicated by a negative number. |
| Back Pain Responder Rate (≥50%) at 6 Months | 6 months | Percentage of participants who responded to the treatment, where response was defined as ≥ 50% reduction in back pain intensity as measured by Visual Analog Scale from baseline to the 6-month follow-up visit. Pain intensity was measured by a 100 mm Visual Analog Scale, with 0 representing no pain and 100 representing the worst pain imaginable. |
| Back Pain Responder Rate (≥30%) at 9 Months | 9 months | Percentage of participants who responded to the treatment, where response was defined as ≥ 30% reduction in back pain intensity as measured by Visual Analog Scale from baseline to the 9-month follow-up visit. Pain intensity was measured by a 100 mm Visual Analog Scale, with 0 representing no pain and 100 representing the worst pain imaginable. |
Countries
Australia, Austria, Belgium, France, Germany, Israel, Netherlands, Spain, Switzerland, United Kingdom
Participant flow
Recruitment details
The first subject enrolled in the study on January 11, 2013. The last subject was enrolled on January 15, 2016 and all subject visits were stopped as of the study termination date of February 12, 2016.
Pre-assignment details
Patients were considered enrolled in the study upon signing an Informed Consent Form. Enrolled subjects then completed additional assessments and were provided a diary to record ther back and leg pain intensity. Upon completion of the at-home diary, eligibility was reassessed based on pain scores. Eligible subjects were then randomized.
Participants by arm
| Arm | Count |
|---|---|
| SQS+OMM Subcutaneous nerve stimulation (SQS) plus optimized medical management (OMM) | 56 |
| OMM Alone Optimized Medical Management alone (OMM) | 60 |
| Total | 116 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Adverse Event | 2 | 0 |
| Overall Study | Early study termination | 10 | 14 |
| Overall Study | Lost to Follow-up | 1 | 0 |
| Overall Study | Protocol Violation | 2 | 3 |
| Overall Study | Withdrawal by Subject | 3 | 7 |
Baseline characteristics
| Characteristic | OMM Alone | Total | SQS+OMM |
|---|---|---|---|
| Age, Continuous | 52.2 years STANDARD_DEVIATION 11.4 | 51.6 years STANDARD_DEVIATION 11.1 | 50.9 years STANDARD_DEVIATION 10.9 |
| Pain intensity at baseline Back pain | 70.1 units on a scale STANDARD_DEVIATION 14 | 69.5 units on a scale STANDARD_DEVIATION 13.7 | 68.8 units on a scale STANDARD_DEVIATION 13.4 |
| Pain intensity at baseline Leg pain | 6.8 units on a scale STANDARD_DEVIATION 11.5 | 7.8 units on a scale STANDARD_DEVIATION 11.2 | 8.9 units on a scale STANDARD_DEVIATION 10.8 |
| Sex: Female, Male Female | 34 Participants | 66 Participants | 32 Participants |
| Sex: Female, Male Male | 26 Participants | 50 Participants | 24 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 18 / 55 | 17 / 60 |
| serious Total, serious adverse events | 19 / 55 | 9 / 60 |
Outcome results
Primary
Effectiveness of Treatment on Reduction of Back Pain Intensity
Percentage of participants who responded to the treatment, where response was defined as ≥ 50% reduction in back pain intensity as measured by Visual Analog Scale from baseline to the 9-month follow-up visit. Pain intensity was measured by a 100 mm Visual Analog Scale, with 0 representing no pain and 100 representing the worst pain imaginable.
Time frame: 9 months
Population: The Intent-to-Treat patient set (ITT) consists of all subjects as they were randomized into the study.~The As Treated consists of all patients of the ITT patient set, but excludes those with major protocol deviations; they are analysed according to last treatment received before the actual assessment, without replacement of missing data.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| SQS+OMM | Effectiveness of Treatment on Reduction of Back Pain Intensity | Intent to treat | 33.9 Percentage of responders |
| SQS+OMM | Effectiveness of Treatment on Reduction of Back Pain Intensity | As treated | 56.7 Percentage of responders |
| OMM Alone | Effectiveness of Treatment on Reduction of Back Pain Intensity | Intent to treat | 1.7 Percentage of responders |
| OMM Alone | Effectiveness of Treatment on Reduction of Back Pain Intensity | As treated | 2.9 Percentage of responders |
Comparison: Subjects with missing information were considered in the test and computation of the proportion for ITT.p-value: <0.0001Fisher Exact
Secondary
Average Change in Back Pain Intensity
Average change in back pain intensity from baseline to the 6 and 9-month follow-up visits. Pain intensity was measured by a 100 mm Visual Analog Scale, with 0 representing no pain and 100 representing the worst pain imaginable. A reduction in average pain score is indicated by a negative number.
Time frame: 6 and 9 months
Population: The Intent-to-Treat patient set (ITT) consists of all subjects as they were randomized into the study.~The As Treated consists of all patients of the ITT patient set, but excludes those with major protocol deviations; they are analysed according to last treatment received before the actual assessment, without replacement of missing data.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| SQS+OMM | Average Change in Back Pain Intensity | Intent to treat: Abs change in back pain at 6 mo | -33.7 units on a scale | Standard Deviation 26.4 |
| SQS+OMM | Average Change in Back Pain Intensity | Intent to treat: Abs change in back pain at 9 mo | -33.3 units on a scale | Standard Deviation 24.5 |
| SQS+OMM | Average Change in Back Pain Intensity | As treated: Absolute change in back pain at 6 mo | -35.0 units on a scale | Standard Deviation 25.5 |
| SQS+OMM | Average Change in Back Pain Intensity | As treated:Absolute change in back pain at 9 mo | -35.9 units on a scale | Standard Deviation 25.3 |
| OMM Alone | Average Change in Back Pain Intensity | As treated:Absolute change in back pain at 9 mo | -4.1 units on a scale | Standard Deviation 14.8 |
| OMM Alone | Average Change in Back Pain Intensity | Intent to treat: Abs change in back pain at 6 mo | -0.6 units on a scale | Standard Deviation 14.3 |
| OMM Alone | Average Change in Back Pain Intensity | As treated: Absolute change in back pain at 6 mo | -2.9 units on a scale | Standard Deviation 12.5 |
| OMM Alone | Average Change in Back Pain Intensity | Intent to treat: Abs change in back pain at 9 mo | -2.7 units on a scale | Standard Deviation 16 |
p-value: <0.0001Regression, Linear
Secondary
Back Pain Responder Rate (≥30%) at 9 Months
Percentage of participants who responded to the treatment, where response was defined as ≥ 30% reduction in back pain intensity as measured by Visual Analog Scale from baseline to the 9-month follow-up visit. Pain intensity was measured by a 100 mm Visual Analog Scale, with 0 representing no pain and 100 representing the worst pain imaginable.
Time frame: 9 months
Population: The Intent-to-Treat patient set (ITT) consists of all subjects as they were randomized into the study.~The As Treated consists of all patients of the ITT patient set, but excludes those with major protocol deviations; they are analysed according to last treatment received before the actual assessment, without replacement of missing data
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| SQS+OMM | Back Pain Responder Rate (≥30%) at 9 Months | Intent to treat | 44.6 Percentage of responders |
| SQS+OMM | Back Pain Responder Rate (≥30%) at 9 Months | As treated | 70.0 Percentage of responders |
| OMM Alone | Back Pain Responder Rate (≥30%) at 9 Months | Intent to treat | 5.0 Percentage of responders |
| OMM Alone | Back Pain Responder Rate (≥30%) at 9 Months | As treated | 11.4 Percentage of responders |
Comparison: Subjects with missing information were considered in the test and computation for ITT.p-value: <0.0001Fisher Exact
Secondary
Back Pain Responder Rate (≥50%) at 6 Months
Percentage of participants who responded to the treatment, where response was defined as ≥ 50% reduction in back pain intensity as measured by Visual Analog Scale from baseline to the 6-month follow-up visit. Pain intensity was measured by a 100 mm Visual Analog Scale, with 0 representing no pain and 100 representing the worst pain imaginable.
Time frame: 6 months
Population: The Intent-to-Treat patient set (ITT) consists of all subjects as they were randomized into the study.~The As Treated consists of all patients of the ITT patient set, but excludes those with major protocol deviations; they are analysed according to last treatment received before the actual assessment, without replacement of missing data.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| SQS+OMM | Back Pain Responder Rate (≥50%) at 6 Months | Intent to treat | 26.8 Percentage of responders |
| SQS+OMM | Back Pain Responder Rate (≥50%) at 6 Months | As treated | 40.0 Percentage of responders |
| OMM Alone | Back Pain Responder Rate (≥50%) at 6 Months | Intent to treat | 1.7 Percentage of responders |
| OMM Alone | Back Pain Responder Rate (≥50%) at 6 Months | As treated | 2.9 Percentage of responders |
Comparison: Subjects with missing information were considered in the test and computation for ITT.p-value: 0.0002Fisher Exact