title: Histological changes and temperature distribution studies of a novel bipolar radiofrequency heating system in degenerated and nondegenerated human cadaver lumbar discs.
abstract: OBJECTIVE
  The purpose of this experimentation was to investigate the safety of a novel cooled bipolar radiofrequency system by examining histology and monitoring temperature distribution in the disc, epidural space, and adjacent to the nerve roots. In our study we used two human cadaver lumbar spines, one moderately to severely degenerated and the other mildly degenerated.
  
  
  METHODS
  Radiofrequency ablation of the disc posterior annulus is a theoretically plausible technique to ablate the nociceptors and to modify collagen of the annulus fibrosus. A novel cooled bipolar radiofrequency system is used to perform a procedure called intervertebral disc biacuplasty to heat the posterior annulus for the treatment of discogenic pain. Four lumbar intervertebral discs were treated in each spine sample using the bipolar system while two lumbar discs of each spine were used as controls.
  
  
  RESULTS
  Temperatures developed in the posterior annulus of the disc were on average 52.35 +/- 5.07 degrees C, while in the intervertebral foramen and in the spinal canal were 38.84 +/- 1.7 degrees C and 38.29 +/- 2.04 degrees C, respectively. There was no histological evidence of damage to any other structures including vertebral end plates, epidural space, or nerve roots. Additionally, there were no histological changes in the posterior annulus that were consistent with heat-induced changes to collagen structure.
  
  
  CONCLUSIONS
  Temperatures reached in the posterior annulus during transdiscal biacuplasty were greater than required (45 degrees C) for neuroablation. Temperatures reached at the neural foramina and epidural were low enough to avoid neural damage.
authors.affiliation: Department of Pain Management, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA. Kapural@ccf.org
authors.forename: Leonardo
authors.initials: L
authors.lastname: Kapural
authors.forename: Nagy
authors.initials: N
authors.lastname: Mekhail
authors.forename: David
authors.initials: D
authors.lastname: Hicks
authors.forename: Miranda
authors.initials: M
authors.lastname: Kapural
authors.forename: Steven
authors.initials: S
authors.lastname: Sloan
authors.forename: Nadeem
authors.initials: N
authors.lastname: Moghal
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Ross
authors.forename: Dejan
authors.initials: D
authors.lastname: Petrinec
mesh_terms: D001831:Body Temperature / Q000502:physiology*; D002102:Cadaver; D002358:Cartilage, Articular / Q000473:pathology; D003627:Data Interpretation, Statistical; D004567:Electrodes, Implanted; D006358:Hot Temperature / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007403:Intervertebral Disc / Q000473:pathology*; D007405:Intervertebral Disc Displacement / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D013130:Spinal Stenosis / Q000473:pathology