LAPAROSCOPIC APPROACHES TO THE LUMBAR VERTEBRAE - AN ANATOMIC STUDY USING A PORCINE MODEL

Study Design. This study described and compared retroperitoneal and tr ansperitoneal laparoscopic approaches to the lumbar vertebrae in pigs, Technical and perioperative complications were evaluated for each app roach. Objectives. The objective of this study was to develop a laparo scopic approach to the lumbar vertebrae that is associated with minima l technical and perioperative complications. Summary of Background Dat a. Laparoscopic techniques have been used extensively in many surgical fields. Recently thoracoscopy has been used to perform a number of th oracic 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. Me thods. With all pigs positioned in left lateral recumbency, retroperit oneal and transperitoneal laparoscopic approaches to the lumbar verteb rae were performed in three pigs. Placement of the insufflation needle s and trocar ports were determined for each approach. Dissection of th e 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 fl uoroscopy was used to confirm marker placement. Gross anatomic dissect ions were performed after the pigs were killed. Results. Loss of pneum oretroperitoneum resulted in surgical termination in two of three pigs undergoing retroperitoneal laparoscopic approach to the lumbar verteb rae. In the remaining pig, difficulty was encountered in mobilization of the psoas major muscle from the lumbar vertebrae, and significant b leeding 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 c omplications included minimal bleeding-and difficulty encountered in m obilization of the renal vascular pedicle.Conclusions. The retroperito neal approach was difficult because of the degree of muscle dissection required for exposure of the lumbar vertebrae. Complications associat ed with the retroperitoneal approach included loss of pneumoretroperit oneum because of entry into the peritoneal cavity, hemorrhage, and lim ited exposure of the lumbar vertebrae, The transperitoneal approach wa s easier technically, allowing identification and access to lumbar ver tebral bodies end intervertebral discs from L1-L6/L7. Operative compli cations associated with the transperitoneal laparoscopic approach were minimal.