title: Effects of ozone applied by spinal endoscopy in patients with chronic pain related to failed back surgery syndrome: a pilot study.
abstract: BACKGROUND
  In the last two decades, ozone has emerged as a treatment for low back pain, applied by means of minimally invasive techniques.
  
  
  OBJECTIVE
  The aim of this study is to assess the effect and safety of ozone therapy applied in the epidural space for chronic pain related to failed back surgery syndrome.
  
  
  METHODS
  The investigators studied 13 sequential patients of both sexes, between 18 and 70 years old, with persistent chronic pain (more than six months) in the lumbar region and in the lower limbs related to failed back surgery syndrome (FBSS). Pain was classified as neuropathic and non-neuropathic regarding the topography (lumbar and lower limb), based on the DN4 (Douleur Neuropathique 4) questionnaire. The patients received the ozone gas in the lumbar epidural space via spinal-sacral endoscopy. Clinical evaluation was performed before, immediately after (24 hours), and 1, 3, and 6 months after intervention with visual analog scale and Oswestry Disability Index (ODI).
  
  
  RESULTS
  Overall, the patients had 43.7% reduction of lumbar pain, 60.9% reduction in leg pain in six months followed by 44.0% of improvement in ODI. The reduction of pain and in the disability index was markedly greater in patients with non-neuropathic predominant pain, 95.2%, 80.6%, and 75.3% improvement in lumbar, leg pain, and ODI respectively, while neuropathic predominant pain patients experienced only 12.5%, 42.4%, and 20.9% improvement, also respectively. No neurological or infectious complications were observed acutely or during the follow-up. The present data suggests that epidural ozone might be a therapeutic option for persistent low back pain, especially in non-neuropathic predominant pain patients, but double-blind controlled studies are still required to prove its efficacy.
authors.affiliation: Pain Center and Division of Functional Neurosurgery, Department of Neurology, School of Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Francisco Nêuton de Oliveira
authors.initials: FN
authors.lastname: Magalhães
authors.forename: Sandra Correia
authors.initials: SC
authors.lastname: Soares
authors.forename: Jaqueline Melo
authors.initials: JM
authors.lastname: Torres
authors.forename: Arthur
authors.initials: A
authors.lastname: Ungaretti
authors.forename: Mariana Fillipi
authors.initials: MF
authors.lastname: Cacciacarro
authors.forename: Manoel Jacobsen
authors.initials: MJ
authors.lastname: Teixeira
authors.forename: Erich Talamoni
authors.initials: ET
authors.lastname: Fonoff
keywords: epiduroscopy; failed back surgery syndrome; minimally invasive surgery; neuropathic pain; ozone; pain; spinal endoscopy