The Effect of Epiduroscopy and Ozone Therapy in Patients With Failed Back Surgery Syndrome
Condition: Low Back Pain; Failed Back Surgery Syndrome
MeSH terms: Syndrome; Back Pain; Low Back Pain; Failed Back Surgery Syndrome
Study type: Interventional
Phase: Phase 2

Summary: 
      The aim of this study is to assess the efficacy and safety of ozone therapy (vs. placebo)
      applied into the epidural space through epiduroscopy in Patients with Failed Back Surgery
      Syndrome. It´s a Prospective, double blind, randomized study. The investigators will study 30
      patients of both sexes between 18 and 70 years with chronic back pain after lumbar spine
      surgery for more than six months. The patients will receive the ozone gas or placebo (oxygen)
      in the lumbar epidural space, using a spinal endoscope inserted through the sacral hiatus by
      local anesthesia or sedation. The patients will be evaluated before the procedure, with 30
      days, with 3, 6 and 12 months after intervention. This will be run by a researcher who will
      have no knowledge of the gas (oxygen or ozone) to be injected into the lumbar epidural space
      with the aid of an epiduroscopic. Will be applied before and after the procedure, pain scales
      (VAS, McGill, Neuropathic Pain 4, Neuropathic Pain Symptom Inventory), quality of life scale
      (WHOQOL), functional scales of pain disability (Roland Morris and Oswestry Disabilities
      Scales). Only one researcher will keep the data confidential until the end of the study.
    

Detailed description: 
      Although surgical discectomy for disc herniation produces better short-term pain relief than
      conservative therapy, there is no convincing evidence for the long-term (10 years) advantage
      of surgery. Between 40% and 80% of patients undergoing back surgery continue to experience
      persistent pain, a condition called Failed Back Surgery Syndrome (FBSS). The symptoms of FBSS
      are of persistent or recurring low back pain and / or leg pain after one or more spinal
      operations. The precise cause of the pain can be difficult to determine due to the complex
      interaction of biological and psychosocial factors. Possible organic causes of FBSS include
      epidural fibrosis, arachnoiditis, mechanical factors, pressure induced changes in the nerve
      root, structural changes in the vertebral column, and lumbar degenerative disease. With a
      second surgical intervention for fibrosis, there is a 65-70% failure rate, with 15-20% of the
      patients reporting worsening of symptoms. Thus, repeated surgery tends to yield poorer
      results.

      The ozone therapy has emerged as an option or additional treatment for these patients, mostly
      in Europe. Despite of its wide use to treat a variety of conditions, ozone therapy is still
      unknown to most physicians. Ozone (O3) is an allotropic form of oxygen, primarily known for
      its ecological properties, industrial applications, but also by its therapeutic effects. Some
      questions persist concerning its potential toxicity as an oxidant agent versus the reported
      clinical efficacy. Several mechanisms of action have been proposed to explain the efficacy of
      the ozone therapy: analgesic, anti-inflammatory and oxidant action on proteoglycan (e.g. in
      the nucleus pulpous). Ozone is administered in the form of an oxygen-ozone gas mixture at
      nontoxic concentrations varying from 1 to 40 µg of ozone per milliliter of oxygen by various
      percutaneous methods for treatment of low back pain. However, still no well-designed studies
      that allow conclusions about the safety and efficacy of ozone in the treatment of low back
      pain.

      Spinal endoscopy, or "epiduroscopy", is the examination of the epidural space by a minimally
      invasive technique that allows the diagnosis and treatment of chronic back pain and
      radiculopathy. The therapeutic potential of epiduroscopy and adhesiolysis, a minimally
      invasive but potentially useful treatment modality in the management of refractory
      radiculopathy, emerged during the 1990s.

      Epiduroscopy is carried out under local anesthesia with the patient awake, thus avoiding
      potential unrecognized pressure effects in the epidural canal. Light intravenous sedation and
      analgesia may be required to ensure full patient cooperation while maintaining verbal
      contact. The patient is positioned prone with a pillow under his/her hips. The procedure is
      carried out under aseptic conditions with antibiotic prophylaxis and requires the use of an
      imagine intensifier. Sacrococcygeal ligament puncture is made with a 17g Tuohy needle and
      followed by a caudal epidurogram to confirm needle placement. A Seldinger technique is then
      used to place an introducer sheath in the sacral epidural canal. A 0.9mm fiber optic scope is
      placed with its tip and the end of a steerable video guided catheter.

      The Video Guided Catheter and endoscope are then advanced via the introducer into epidural
      space. Slow irrigation with saline allows visualization of epidural space by gentle
      distension. Adhesiolysis can be carried out under direct vision by blunt dissection of the
      adhesions using the tip of the video guided catheter. Blunt dissection coupled with
      hydrostatic distension of the epidural space thus creates a pocket through which injected
      drug can access symptomatic nerve roots.

      Several drugs have been used within the epidural space through the spinal endoscopy including
      steroid, local anesthetic, hyaluronidase, saline solution, clonidine and ozone most recently.
      Blind epidural injections of these therapeutic substances can, in some patients; fail to flow
      towards a symptomatic root due to obstruction by epidural fibrosis. Such patients may,
      therefore, benefit more from epidural injection if flow of inject towards the symptomatic
      root is facilitated following endoscopic division of epidural adhesions.

      Thus, the investigators find this model of pain would be appropriate to evaluate the effects
      of ozone in treatment for the lumbar pain by comparison with a placebo, using the
      epiduroscopy to apply it.
    

Intervention name(s): Epiduroscopy with oxygen therapy; Epiduroscopy with ozone therapy
Intervention type(s): Procedure; Procedure
Intervention description(s): Patients in this group will receive 30 mL of oxygen by epiduroscopy.; Patients in this group will receive 30 mL of ozone at a concentration of 30 mcg / ml by epiduroscopy.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: low back pain; failed back surgery syndrome (FBSS); epidural fibrosis; ozone therapy; oxygen therapy; epiduroscopy; spinal endoscopy