Thoracoscopic Corpectomy and Reconstruction

Advantages and Disadvantages

Several advantages are offered by the minimally invasive thoracoscopic approach over an open thoracotomy. Multiple vertebral levels and the ventral spinal canal can be visualized and treated, without increasing surgical exposure, when access ports are properly placed. The surgical field can be imaged with excellent resolution, using modern high-definition endoscopic technology. The small intercostal incisions negate the need for rib resection and retraction, unlike open thoracotomy approaches, which necessitate large incisions, extensive dissection of intercostal muscles, rib resection, and retraction of the chest wall. The thoracoscopic approach is associated with reduced blood loss, need for blood transfusion, days of mechanical ventilation, perioperative wound pain, incidence of pulmonary and shoulder dysfunction, length of hospital stay, and days to rehabilitation. ^,

For most spine surgeons, the largest obstacle to using the thoracoscopic approach is unfamiliarity with the technique and high technical demand. The operation is performed distant from the surgical site in two dimensions, based solely on thoracoscopic image guidance, which requires most spine surgeons to acquire a new set of skills. Before operating on a patient, the surgeon must gain familiarity with the new technique in practical and didactic training sessions. The surgeon and operating room staff must overcome a steep learning curve while gaining familiarity with the approach, and this can initially increase operative times by several hours. Anesthesia monitoring and double-lumen ventilation may also increase operative times. Conversion to an open thoracotomy may be required with difficult cases or when intraoperative complications cannot be resolved with the thoracoscopic technique. Finally, extensive intrathoracic disease, whether pulmonary or spinal, may be difficult to address with the thoracoscopic approach and may require open minithoracotomy.

Indications and Contraindications

The thoracoscopic approach for corpectomy is best suited to patients with thoracolumbar disease limited to one vertebral body between T5 and L1. The most common indication for thoracoscopic spine surgery is in the setting of trauma. Among patients with traumatic spinal injury, ventral spinal reconstruction for biomechanical instability is the most common surgical indication. Traumatic spinal instability may be secondary to fracture, injury to the intervertebral discs, or significant ligamentous disruption. The mainstay of treatment for thoracolumbar fractures is rigid fixation with transpedicular screw and rod constructs. The decision to add anterior column reconstruction is based on the loadbearing capacity of the injured spinal segment. The load-sharing classification system developed by McCormack and colleagues established a correlation between failure of posterior short segment fixation and the characteristics of the most significantly injured vertebrae. Fractures with a high degree of vertebral body comminution, fragment apposition, and postoperative deformity correction were found to be at high risk for posterior instrumentation failure. Thoracoscopic surgery for reconstruction of the anterior loadbearing elements is indicated in these patients. Although patients with neurological deficits from fracture intrusion into the spinal canal comprise a minor subgroup of patients with traumatic spine injury, they are also indicated for spinal canal decompression and stabilization.

For metastatic spine disease, thoracolumbar surgery is indicated for treatment of spinal instability, radiation treatment failures, anterior spinal cord compression secondary to epidural tumor causing neural compression, and pain intractable to conservative measures, or to obtain a histological diagnosis. ^, The thoracoscopic approach is useful for minimally invasive resection of vertebral body metastasis with or without ventral spinal canal involvement and for anterior column reconstruction with interbody placement and ventrolateral instrumentation. ^,

The thoracoscopic approach is contraindicated in patients unable to tolerate single-lung ventilation because of severe cardiopulmonary disease, such as acute posttraumatic lung failure, significant pulmonary contusions, advanced chronic obstructive pulmonary disease or asthma, or hemodynamic instability. This approach is also contraindicated in patients with significant medical diseases, disturbances in hemostasis, or terminal illnesses precluding surgical treatment. The surgery may be technically challenging in patients with a history of trauma, prior surgery, or infection, because of the development of dense pleural adhesions. In cases with substantial posterior column disruption or involvement, stand-alone anterior surgery may be insufficient to achieve spinal stability, and supplemental posterior fixation should be considered.

Preoperative Assessment and Planning