title: Recurrent thoracolumbar intervertebral disc extrusion after hemilaminectomy and concomitant prophylactic fenestration in 662 chondrodystrophic dogs.
abstract: OBJECTIVE
  To determine the prevalence and location of recurrent thoracolumbar intervertebral disc extrusion (T-L IVDE) after hemilaminectomy with prophylactic fenestration (PF) and to document PF-related complications.
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  Chondrodystrophic dogs (n = 793).
  
  
  METHODS
  In 662 successfully recovered dogs (>1 year follow-up), the prevalence of dogs with recurrent T-L IVDE that required a 2nd surgery and dogs with clinical signs that improved without surgery was evaluated. Prevalence of second disc extrusions (SDEs) within T11-L4 intervertebral discs was compared between PF discs and non-PF discs.
  
  
  RESULTS
  T-L SDEs were intraoperatively confirmed in 15 dogs (2.3%), 2-61 months after initial surgery and 66 dogs (10.0%) had signs of T-L IVDE recurrence that improved without surgery (mean follow-up, 44.7 months). No dog had further extrusion at the initial T-L site. SDE occurred at a PF disc (n = 1), adjacent to PF discs (8), or at distant discs (6). Prevalence of SDE in non-PF discs was 26.2 times higher than PF discs (95% CI: 3.4, 203.4; P < .001). Major PF-related complications included iatrogenic introduction of the disc material into the spinal canal (n = 1), and vertebral subluxation/instability (3) at 1-88 months postoperatively.
  
  
  CONCLUSIONS
  SDE is more likely to occur at non-PF discs than PF discs when PF is performed at spaces predisposed to disc extrusion. PF is a safe and effective treatment to prevent SDE in chondrodystrophic dogs.
authors.affiliation: Aikawa Veterinary Medical Center, Tokyo, Japan. taikawa@wb3.so-net.ne.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Aikawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujita
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Shibata
authors.forename: Taishi
authors.initials: T
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000473:pathology / Q000601:surgery*; D004285:Dogs; D005260:Female; D007405:Intervertebral Disc Displacement / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D007796:Laminectomy / Q000009:adverse effects / Q000662:veterinary*; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D008297:Male; D010009:Osteochondrodysplasias / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D012008:Recurrence; D012189:Retrospective Studies