title: Safety and effectiveness of a polyvinyl alcohol barrier in reducing risks of vascular tissue damage during anterior spinal revision surgery.
abstract: METHODS
  This study was conducted as a controlled, prospective investigation to show the safety and efficacy of a polyvinyl alcohol (PVA) device in a sheep model.
  
  
  OBJECTIVE
  To evaluate the ability of a permanent PVA hydrogel barrier to reduce the risk of potential vessel damage during anterior vertebral revision surgery, to provide a nonadhesive barrier at the surgical site, and to create a surgical revision plane of dissection.
  
  
  BACKGROUND
  The development of scar tissue and adhesions presents a significant postoperative problem in spine surgery, where adhesion involvement of overlying structures can cause pain, neurovascular complications, and present a difficult surgical environment during revisions.
  
  
  METHODS
  The devices were implanted onto the ventral surface of exposed lumbar intervertebral discs using an anterolateral approach. One disc separated from the study site was also exposed to serve as a control. Three sheep each were then evaluated with an explant procedure at 30 and 90 days. Extensive sampling was undertaken to evaluate gross anatomic, micropathologic, and biochemical environments and properties of the device.
  
  
  RESULTS
  The structural properties and appearance of the device remained intact at both 30 and 90 days. The material remained flexible, hydrophilic, and soft, without visible resorption or decomposition. The material was well tolerated by the animal, with minimal histologic signs of inflammation or rejection. Tissue planes were easily able to be localized by the surgeon attempting to locate the prior surgical site at the time of resection.
  
  
  CONCLUSIONS
  The PVA vessel shield effectively protected the structures overlying the sheep spine during revision, providing a clear dissection plane for resection at repeat surgery. The overlying structures separated from the previous surgical site with no adhesion, and allowed safe separation of adjacent tissues without the use of sharp dissection.
authors.affiliation: Resurgens Spine Center, Resurgens Orthopaedics, Saint Joseph's Translational Research Institute, Atlanta, GA, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Jeffords
authors.forename: Jinsheng
authors.initials: J
authors.lastname: Li
authors.forename: Deepal
authors.initials: D
authors.lastname: Panchal
authors.forename: Guilhem
authors.initials: G
authors.lastname: Denoziere
authors.forename: Donald
authors.initials: D
authors.lastname: Fetterolf
mesh_terms: D000818:Animals; D001158:Arteries / Q000293:injuries*; D017586:Diskectomy / Q000009:adverse effects*; D008159:Lumbar Vertebrae / Q000601:surgery*; D011142:Polyvinyl Alcohol / Q000627:therapeutic use*; D011183:Postoperative Complications / Q000517:prevention & control*; D012086:Reoperation / Q000009:adverse effects; D018570:Risk Assessment; D012756:Sheep; D016896:Treatment Outcome
chemical_list: D011142:Polyvinyl Alcohol