Condition category
Signs and Symptoms
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
Chronic pain is one of the most common and hard to control medical conditions. Low back pain is a major health problem throughout the world and conventional medical and surgical management is often not sufficient for the treatment of chronic pain. Spinal Cord Stimulation (SCS) has been used to treat low back pain in people with continuous or recurring pain following invasive spinal surgery. There is good evidence to recommend SCS in people with back pain without a history of spinal surgery, particularly because SCS is a less invasive and reversible therapy that may provide greater long-term benefits than more invasive surgical approaches. This study aims to further investigate the pain relief achieved when using Nevro's Senza System to treat low back pain in patients who have not undergone invasive spinal surgery.

Who can participate?
Eligible participants will have experienced chronic low back pain for at least 6 months and for whom conventional medical management, such as physical therapy or minimally invasive interventions, has not proven effective.

What does the study involve?
All participants will have a trial phase period of stimulation with the Senza System of a minimum of 7 days and a maximum of 30 days to determine if they will respond to the treatment. If the treatment is successful and satisfactory pain relief is achieved, a permanent Implantable Pulse Generator (IPG) will be implanted. Participants who receive the permanent system will be required to attend follow-ups for 12 months following implantation.

What are the possible benefits and risks of participating?
Possible benefits include pain relief and improvement in quality of life. Risks to participants are the same as for all SCS devices. These could include surgical complications, increased pain in the areas being treated, pain in other areas, uncomfortable stimulation and allergy to medical device materials. The device or its components may malfunction, requiring surgical revision of the leads or IPG.

Where is the study run from?
Guy's and St Thomas' Hospital (London, UK)

When is the study the starting and how long is it expected to run for?
The study began in April 2012 will end in March 2014.

Who is funding the study?
Nevro Corp (CA, USA)

Who is the main contact?
Dr Adnan Al-Kaisy  

Trial website

Contact information



Primary contact

Dr Adnan Al-Kaisy


Contact details

Guy's and St. Thomas' Hospital
Westminster Bridge Road
United Kingdom
+44 (0)207 188 7188

Additional identifiers

EudraCT number number

Protocol/serial number

CA2011 VB UK

Study information

Scientific title

Evaluation of the SenzaTM Spinal Cord Stimulation System for the treatment of chronic back pain in subjects without prior spinal surgery


Study hypothesis

The purpose of this study is to evaluate the Senza System for the treatment of symptoms of chronic low back pain in subjects with no history of invasive spine surgery.

Ethics approval

NRES Committee North East - Northern and Yorkshire, 12/04/2012, ref: 11/NE/0047

Study design

Single-center single-arm open-label observational study

Primary study design


Secondary study design

Non-randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Chronic low back pain in subjects who have not had spinal surgery


Spinal Cord Stimulation with Nevro's Senza System

This is a single center, open label, prospective study to evaluate the effectiveness of the Senza System in subjects with chronic low back pain who have not had invasive spinal surgery. Subjects meeting the eligibility criteria will be consented, enrolled, and will undergo a baseline evaluation. All subjects will have a Trial Phase period of stimulation of a minimum of 7 days and a maximum of 30 days to determine if they will respond to therapy.

If the subject has a 50% or greater pain reduction in back pain based on VAS at the end of Trial Phase, they are eligible for permanent implant for the device system. Treating physician will also assess adverse events, subject's tolerance of the device, functional changes, and pain medication use during the Trial Phase before the decision is made to proceed with permanent implant.

Subject will be assessed 12 months after activation of the permanent device. Pain, functional changes and medication usage will be asessed at 1, 3, 6, 9 and 12 months after permanent device activation.

Intervention type



Not Applicable

Drug names

Primary outcome measure

Comparison of percentage change from Baseline in back pain (as measured by VAS) at 1, 3, 6, 9 and 12 months.

Secondary outcome measures

1. Comparison of percentage change from Baseline in leg pain (as measured by VAS) at 1, 3, 6, 9 and 12 months
2. Comparison of change from Baseline in functional changes as measured by the Oswestry Disability Index at 3, 6, 9, and 12 months
3. Comparison of change from Baseline in quality of life as measured by SF-36 at 3, 6, 9 and 12 months
4. Comparison of change from Baseline in quality of life as measured by EQ-5D at 3, 6, 9 and 12 months
5. The change in work status from Baseline to follow-ups at 3, 6, 9, and 12 months
6. Change from Baseline in sleep disturbance at 1, 3, 6, 9, and 12 months
7. Paresthesia generated by the stimulator at Post-Permanent Device Activation
8. Adverse events collected during the study at all visits
9. The percentage subjects who experience at least 50% reduction in pain due to SCS therapy (as assessed by VAS) for back pain at 3, 6 and 12 months
10. Percentage change from Baseline in back and leg pain (as assessed by Subject Diary VAS) at 1, 3, 6, 9 and 12 months
11. Change from Baseline in pain and opioid medication usage
12. To learn about the subject’s clinical trial experience through videotaping
13. To summarize the subject’s global impression of change
14. To summarize the subject’s satisfaction with the Senza System
15. To summarize subject’s willingness to recommend to another subject with same condition

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Age greater than 18 years, less than 65 years old
2. Low back pain for more than 6 months having failed conservative treatment (e.g., physical therapy, multiple facet joint injections)
3. Low back pain intensity ≥5 out of 10 cm on the Visual Analog Scale (VAS) at enrollment
4. Low back pain predominates over any radicular pain (VAS back pain 2 points or more greater than VAS leg pain)
5. Degenerative disc disease confirmed by imaging or internal disc disruption as confirmed by discography
6. On stable pain medications, as determined by the Investigator, for at least 28 days prior to enrolling in this study and not change medication dosage without consulting Investigator
7. Legally able to provide informed consent
8. Able to comply with study-related requirements, procedures and visits

Participant type


Age group




Target number of participants

20 with permanent implants

Total final enrolment


Participant exclusion criteria

1. Had previous spinal fusion surgery
2. A current diagnosis of a progressive neurological disease such as multiple sclerosis, chronic inflammatory demyelinating polyneuropathy, rapidly progressive arachnoiditis, rapidly progressive diabetic peripheral neuropathy, brain or spinal cord tumor, or severe/critical central or foraminal spinal stenosis
3. Mechanical spine instability detected by a spinal surgeon (validation by flexion/extension films of lumbar spine within the past 6 months showing 4 mm or more translational movement or excessive angular movement manifested by >5 degrees segmental angular movement) e.g. any forms of spondylolisthesis
4. A medical condition or pain in other area(s), not intended to be treated with SCS, that could interfere with study procedures, accurate pain reporting, and/or confound evaluation of study endpoints, as determined by the Investigator
5. Diabetic who is poorly controlled through diet and/or medication (determined by the Investigator)
6. Bleeding diathesis such as coagulopathy or thrombocytopenia
7. Immunocompromised and at an increased risk for infection
8. Systemic infection or local infection that would contraindicate SCS placement
9. Metastatic malignant disease or active local malignant disease
10. Pregnant (if female and sexually active, subject must be using a reliable form of birth control, be surgically sterile or be at least 2 years post-menopausal)
11. Active alcohol, marijuana, recreational or prescription drug abuse or dependence or unwilling to stop/reduce excessive inappropriate medication.
12. Evidence of an active disruptive psychological or psychiatric disorder or other known condition significant enough to impact perception of pain, compliance of intervention and/or ability to evaluate treatment outcome as determined by the Investigator
13. Life expectancy of less than 1 year
14. Concomitant participation in clinical trial (device or drug)
15. An existing drug pump, SCS system, and/or another active implantable device
16. An interventional procedure and/or surgery within the past 30 days for treatment of pain condition
17. Inability to manage the technical demands of the SCS equipment

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Guy's and St. Thomas' Hospital
United Kingdom

Sponsor information


Nevro Corp (USA)

Sponsor details

4040 Campbell Avenue
Suite 210
Menlo Park
United States of America

Sponsor type




Funder type


Funder name

Nevro Corp (USA)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2017 results in:
2018 results in: (added 02/07/2019)

Publication citations

Additional files

Editorial Notes

02/07/2019: Publication reference and total final enrolment number added. 04/10/2017: Publication reference added.