Thoracic Direct Lateral Corpectomy



Thoracic Direct Lateral Corpectomy


Mathew Cyriac

Keith Michael



Illustrative case

A 55-year-old male underwent previous T10-L2 percutaneous pedicle screw instrumentation stabilization without decompression for T12 pathologic burst fracture because of metastatic lung cancer. At 2 months post-op, he developed thoracic myelopathic symptoms because of further retropulsion of posterior bone fragment and tumor resulting in cord and conus medullaris compression.


Radiologic Assessment



  • Same radiographic assessment as for lumbar extreme lateral interbody fusion (XLIF). Look at anteroposterior (AP) and lateral radiographs to get a general idea of overall alignment.



    • Note number of ribs, especially where T12 is on the AP (Figure 12-1).


    • Note number of lumbar vertebral bodies on lateral and if on any transitional lumbosacral anatomy. Use both the AP and lateral x-ray to help count the appropriate vertebral body to address. Fractures are easier to localize than degenerative cases (Figure 12-1).






      Figure 12-1 ▪ Anteroposterior/lateral CT scout films showing T12 pathologic burst fracture with previous T10 to L2 percutaneous pedicle screw instrumentation.



  • Look at axial MRI to determine proximity of inferior vena cava and aorta to vertebral body (Figure 12-2). In the midthoracic spine, the vessels can be draped over the left lateral aspect of the vertebral body. Right-sided approach is warranted in that case (Figure 12-3).






Figure 12-2 ▪ A (Sagittal) and B (axial) T2 MRI showing T12 pathologic burst fracture and tumor extension with compression of conus medullaris. Note on the axial the position of aorta and inferior vena cava. For thoracolumbar lateral approach (T11-L2), will be docking the retractor on the left side.






Figure 12-3 ▪ Axial CT scan showing the descending aorta proceeding from the lateral aspect in upper thoracic to anterior aspect of vertebral body in the lower thoracic.




Special Equipment



  • Refer to lumbar XLIF chapter for full details. Reverse OR table. There is often no need to break the bed.



    • At L1-2 level, the table break can be positioned over the targeted level to move the ribs out of the way and facilitate access to the disk space. At other thoracic levels, no table break is needed. For corpectomy, part of the rib will be removed, so opening up the rib interspace is not needed (Figure 12-4).







      Figure 12-4 ▪ Typically no table break is needed. At L1-2, table break is positioned over thoracolumbar junction to move ribs out of the way. If table break is needed, it should be very small. For corpectomy, no table breaking is needed because part of the rib will be removed.


  • Single-lumen endotracheal intubation is sufficient.



    • Double-lumen intubation and ipsilateral lung deflation are not necessary.


  • Compared to lumbar XLIF, in addition to free running electromyograms (EMGs), somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) are required to monitor the thoracic spinal cord.


Positioning



  • Same setup as for a lumbar XLIF, except:



    • No need for bump under greater trochanter because iliac crest will not be in the way.


    • Usually, do not need to break the bed


    • In mid- to upper thoracic spine, right-sided approach if aorta is draped over left side of the vertebral body. Check pre-op MRI.


  • Critical to obtain perfect AP and lateral views of the involved disk space or vertebral body (Figure 12-5)






Figure 12-5 ▪ A, Anteroposterior x-ray focused at T12 showing distinct endplates and T12 spinous process centered in between the pedicles. B, Lateral x-ray showing distinct T12 endplate.



Localization



  • Similar to lumbar XLIF. Please refer to XLIF chapter.


  • Mark out the anterior, posterior, superior, and inferior margins of the targeted vertebral body including the cranial and caudal adjacent disk space on the lateral x-ray (Figure 12-6).


  • Mark the traversing rib overlying the vertebral body which will be resected.






Figure 12-6 ▪ Vertebral body margins (blue box) and overlying rib marked out (Picture from a cadaveric dissection).


Approach

T11 and above is a retropleural approach preserving the parietal pleura. T12-L1, thoracolumbar junction, is through the diaphragm, into the thoracic cavity through the retropleural space (transdiaphragmatic, retropleural). At L1-2, it is through the diaphragm and into the retroperitoneal space (transdiaphragmatic retroperitoneal). Sometimes, even L1-2 will be in retropleural/costophrenic recess.


Approach (Corpectomy): T11 and Above—Retropleural