Video-assisted thoracoscopic surgery versus open thoracotomy for anterior thoracic spinal fusion -: A comparative radiographic, biomechanical, and histologic analysis in a sheep model

Study Design. In this in vivo investigation, a sheep model was used to compare the efficacy of a video-assisted thoracoscopic approach and a traditional thoracotomy in promoting a successful interbody spinal arthrodesis. Objectives. To compare the incidence of successful anterior spinal arthrodesis among three stabilization techniques-iliac crest, Bagby and Kuslich device, and Z-Plate-performed using a video-assisted thoracoscopic approach and conventional open thoracotomy approaches. Summary of Background Data. A clinical outcome study on open versus endoscopic spinal fusion is not yet available. Moreover, no basic scientific investigations have been conducted to determine whether the success of an endoscopic arthrodesis is comparable to that of a conventional open procedure. Methods. Fourteen Western Crossbred sheep underwent three identical destabilization procedures at T5-T6, T7-T8, and T9-T10, in which the anterior and middle osteoligamentous columns of the spine were resected, followed by three randomized reconstruction procedures using iliac autograft alone, Bagby and Kuslich device packed with iliac autograft, and Z-plate stabilization with iliac autograft. In seven sheep, the entire destabilization-reconstruction procedure was performed using a video-assisted thoracoscopic surgical approach. In the remaining seven, the procedure was performed by conventional open thoracotomy. Results. Histomorphometric and biomechanical evaluation demonstrated that the video-assisted thoracoscopic approach and open thoracotomy arthrodesis had comparable bone formation and biomechanical properties (P > 0.05), However, the Z-plate fusions, as a group, demonstrated increased flexion-extension stiffness properties and trabecular bone formation compared with the autograft and Bagby and Kuslich device fusions (P < 0.05). Conclusions. Thoracic interbody spinal fusions performed by thoracoscopy have demonstrated histologic, biomechanical, and radiographic equivalence to those performed by a thoracotomy approach. However, in the endoscopy group, intraoperative complications causing longer operative times, higher estimated blood toss, and increased animal morbidity indicated a substantial learning curve associated with the adoption of this surgical technique.