Comparative Study of Sham Versus Mild® Procedure in Patients Diagnosed With Symptomatic Lumbar Central Canal Stenosis

This study has been completed.
Vertos Medical, Inc.
Information provided by (Responsible Party):
Eric J. Grigsby, MD, Napa Pain Institute Identifier:
First received: April 30, 2010
Last updated: June 11, 2013
Last verified: June 2013

This is a single-center, randomized, prospective, double-blind, clinical study to assess the clinical application and outcomes with mild® devices versus sham in patients with symptomatic moderate to severe central canal spinal stenosis. Sham patients were eligible to choose to cross-over and have the actual decompression procedure after week 6 exam.

Condition Intervention
Lumbar Spine Stenosis Central Canal
Device: Percutaneous Lumbar Decompression
Device: Sham lumbar decompression

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Comparative Study of Sham Versus Mild® (Minimally Invasive Lumbar Decompression) Procedure in Patients Diagnosed With Symptomatic Moderate to Severe Lumbar Central Canal Stenosis

Further study details as provided by Napa Pain Institute:

Primary Outcome Measures:
  • Visual Analog Scale (VAS) <=4 [ Time Frame: Week 6 to 12 prior to cross-over ] [ Designated as safety issue: No ]
    Using VAS, pain is measured on a 0 to 10 point scale where 0 represents no pain and 10 indicates severe pain. A post-treatment score of 4 points is the accepted threshold between a "mild" pain score of 1-3 points and a "moderate to severe" pain score of 5 to 10 points which represents debilitating pain that would qualify the patient for a different or additional treatment option. All patients in each arm who reported a pain score of 4 or less at six to twelve weeks post-treatment are reported below.

  • Visual Analog Scale (VAS) <=4 [ Time Frame: Week 6 to 12 & Year One After Sham to mild x-over ] [ Designated as safety issue: No ]
    VAS as measured on a 10-point scale. A score of 4 or less after treatment is considered favorable, as it indicates pain is less than the "moderate to severe" categories represented by scores of 5 to 10. All patients in each arm who reported a pain score of 4 or less at Week 6-12 and Year 1 are reported below.

  • Visual Analog Scale (VAS) Mean Improvement [ Time Frame: Baseline and Year 1 ] [ Designated as safety issue: No ]
    VAS ten point scale where 0 = no pain and 10 represents worst pain imaginable. Mean improvement of two or more points is considered clinically relevant. The mean improvement from Baseline to Year-1 is presented below for the two treatment groups.

Enrollment: 40
Study Start Date: April 2010
Study Completion Date: October 2011
Primary Completion Date: October 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Decompression with mild® Device Kit
Fluoroscopically guided percutaneous lumbar decompression using the Vertos mild® Device Kit for bone and tissue removal to decompress the targeted stenosed level(s).
Device: Percutaneous Lumbar Decompression
Fluoroscopic percutaneous lumbar decompression of the central spinal canal
Other Name: mild® Device Kit percutaneous decompression
Sham Comparator: Sham lumbar decompression
Sham procedure of fluoroscopically guided percutaneous placement of mild® Device Kit instrumentation with no removal of bone or tissue.
Device: Sham lumbar decompression
Sham fluoroscopic percutaneous lumbar decompression with no bone or tissue removal.


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Symptomatic and lumbar spine stenosis (LSS) primarily caused by dorsal element hypertrophy.
  • Prior failure of conservative therapy and Oswestry Disability Index (ODI) Score of >20%.
  • Radiologic evidence of LSS, ligamentum flavum hypertrophy (typically > 2.5mm)confirmed by pre op MRI and/or CT.
  • Central canal cross sectional area clearly reduced per MRI/CT report.
  • If present, anterior listhesis ≤ 5.0mm (preferred) and stable.
  • Able to walk at least 10 feet unaided before being limited by pain.
  • Available to complete 26 weeks of follow-up.
  • A signed Informed consent Form is obtained from the subject.
  • Adults at least 18 years of age.

Exclusion Criteria:

  • Prior surgery at intended treatment level.
  • History of recent spinal fractures with concurrent pain symptoms as determined by the Investigator.
  • Disabling back or leg pain from causes other than LSS (e.g. acute compression fracture, metabolic neuropathy, or vascular claudication symptoms, etc.).
  • Disk protrusion or osteophyte formation severe enough to confound study outcome.
  • Facet hypertrophy severe enough to confound study outcome.
  • Bleeding disorders and/or current use of anti-coagulants.
  • Use of acetylsalicylic acid (ASA) and/or non-steroidal anti-inflammatory (NSAID) within five days of treatment.
  • Epidural steroid administration within prior 3 weeks(of procedure or sham)
  • Inability of the subject to lie prone for any reason with anesthesia support (e.g. chronic obstructive pulmonary disease (COPD), obesity, etc.).
  • Metabolic wound healing pathologies deemed by Investigator to compromise study outcome.
  • Dementia and/or inability to give informed consent.
  • Pregnancy and/or breastfeeding.
  • On Workman's Compensation or considering litigation associated with back pain.
  Contacts and Locations
Please refer to this study by its identifier: NCT01129921

United States, California
Napa Pain Institute
Napa, California, United States, 94558
Sponsors and Collaborators
Napa Pain Institute
Vertos Medical, Inc.
Principal Investigator: Eric Grigsby, MD Napa Pain Institute
  More Information

No publications provided

Responsible Party: Eric J. Grigsby, MD, Founder / Medical Director, Napa Pain Institute Identifier: NCT01129921     History of Changes
Other Study ID Numbers: Protocol #G01
Study First Received: April 30, 2010
Results First Received: January 7, 2013
Last Updated: June 11, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by Napa Pain Institute:
Lumbar Spine Stenosis

Additional relevant MeSH terms:
Constriction, Pathologic
Pathological Conditions, Anatomical processed this record on April 16, 2014