A Less-Invasive Retroperitoneal Lumbar Approach: Animal Feasibility Study and Primary Clinical Study.

STUDY DESIGN: Surgical approach development in an animal model, and a prospective study comparing clinical outcomes between novel and conventional approaches in thoracolumbar burst fracture fixation.

OBJECTIVE: To investigate the feasibility of a less-invasive retroperitoneal approach to the lumbar spine in a sheep model and to compare the clinical outcomes of anterior reconstruction in the treatment of thoracolumbar burst fractures using novel and conventional approaches.

SUMMARY OF BACKGROUND DATA: The anterior retroperitoneal lumbar approach is well established for anterior lumbar surgical procedures in both humans and animal models. However, potential concerns include the increased risk of complications such as soft tissue trauma, and extended periods of rehabilitation postoperatively.

METHODS: A less-invasive retroperitoneal approach was designed in a sheep model with minimal soft tissue dissection to keep the abdominal and paravertebral muscles intact. Eight sheep underwent anterior lumbar interbody fusion (ALIF) using this approach. In the clinical study, 48 patients with thoracolumbar burst fractures underwent anterior decompression and reconstruction. The less-invasive approach and conventional approach were applied in 12 cases and 36 cases, respectively. The clinical outcomes during the minimum 12-month follow-up of the two groups were compared.

RESULTS: With the less-invasive approach, ALIF was accomplished in all sheep, and no surgical complications were observed. In the clinical study, operation time, blood loss, and duration of hospitalization were comparable between two groups. Using the less-invasive approach decreased the length of incision, 3-day postoperative visual analogue scale (VAS) score, postoperative independent standing, and narcotic-dependent duration. No surgical complications were observed in either group.

CONCLUSION: Our results and early experience suggests that the less-invasive retroperitoneal approach is safe and effective for anterior lumbar surgery. Compared to the conventional approach, significantly better postoperative rehabilitation and abdominal muscle preservation were seen with this novel approach.