title: Laparoscopic approaches to the lumbar vertebrae. An anatomic study using a porcine model.
abstract: METHODS
  This study described and compared retroperitoneal and transperitoneal laparoscopic approaches to the lumbar vertebrae in pigs. Technical and perioperative complications were evaluated for each approach.
  
  
  OBJECTIVE
  The objective of this study was to develop a laparoscopic approach to the lumbar vertebrae that is associated with minimal technical and perioperative complications.
  
  
  BACKGROUND
  Laparoscopic techniques have been used extensively in many surgical fields. Recently, thoracoscopy has been used to perform a number of thoracic spinal procedures, including thoracic discectomy, and anterior osteotomy, release, and fusion. To date, there have been no published reports describing laparoscopic approaches to the lumbar vertebrae.
  
  
  METHODS
  With all pigs positioned in left lateral recumbency, retroperitoneal and transperitoneal laparoscopic approaches to the lumbar vertebrae were performed in three pigs. Placement of the insufflation needles and trocar ports were determined for each approach. Dissection of the lumbar vertebrae were performed, and the technical and perioperative complications recorded. Radio-opaque markers were placed to identify the dissected lumbar intervertebral disc spaces, and intraoperative fluoroscopy was used to confirm marker placement. Gross anatomic dissections were performed after the pigs were killed.
  
  
  RESULTS
  Loss of pneumoretroperitoneum resulted in surgical termination in two of three pigs undergoing retroperitoneal laparoscopic approach to the lumbar vertebrae. In the remaining pig, difficulty was encountered in mobilization of the psoas major muscle from the lumbar vertebrae, and significant bleeding occurred. The transperitoneal approach to the lumbar vertebrae resulted in rapid mobilization of the psoas musculature and exposure of the lumbar vertebral bodies and discs of L1-L6/L7. Intraoperative complications included minimal bleeding and difficulty encountered in mobilization of the renal vascular pedicle.
  
  
  CONCLUSIONS
  The retroperitoneal approach was difficult because of the degree of muscle dissection required for exposure of the lumbar vertebrae. Complications associated with the retroperitoneal approach included loss of pneumoretroperitoneum because of entry into the peritoneal cavity, hemorrhage, and limited exposure of the lumbar vertebrae. The transperitoneal approach was easier technically, allowing identification and access to lumbar vertebral bodies and intervertebral discs from L1-L6/L7. Operative complications associated with the transperitoneal laparoscopic approach were minimal.
authors.affiliation: Department of Surgery, Royal University Hospital, Saskatoon, Saskatchewan, Canada.
authors.forename: S R
authors.initials: SR
authors.lastname: Southerland
authors.forename: A M
authors.initials: AM
authors.lastname: Remedios
authors.forename: J G
authors.initials: JG
authors.lastname: McKerrell
authors.forename: D
authors.initials: D
authors.lastname: Litwin
mesh_terms: D000818:Animals; D005260:Female; D007403:Intervertebral Disc / Q000601:surgery; D007431:Intraoperative Complications; D010535:Laparoscopy / Q000379:methods*; D008159:Lumbar Vertebrae / Q000033:anatomy & histology* / Q000601:surgery*; D016658:Psoas Muscles / Q000601:surgery; D013552:Swine / Q000033:anatomy & histology*