Indications
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Tumor, fracture, tuberculosis, or other pathology of the vertebral body requiring direct decompression of the spinal canal with resection of anterior pathology
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Instability of anterior spinal elements, requiring restoration of height and stability to prevent progressive deformity and kyphosis
Planning and positioning
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The focus here is on the anterolateral-retroperitoneal approach to a lumbar corpectomy and fusion. There are several options for approaching the anterior lumbar spine, including (1) anterolateral-retroperitoneal with the patient in a lateral position, (2) endoscopic anterolateral-retroperitoneal, (3) anterior-retroperitoneal with the patient supine, (4) anterior-transperitoneal with the patient supine, and (5) lateral extracavitary with the patient in a lateral position. All approaches require special consideration of the anatomy of the ribs and diaphragm for exposure of L2 and above. Lateral approaches require special consideration of the anatomy of the iliac crest for exposure of L5 and below.
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Although a left-sided approach is generally preferred, important exceptions include predominantly right-sided pathology and cases of abdominal aortic aneurysm, calcifications, or other aortic disease that impairs safe mobilization of the aorta. A right-sided approach is difficult because of retraction of the liver and the dangers of retracting the thin-walled inferior vena cava.
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The approach to the anterior spine with requisite mobilization of the great vessels is frequently performed with the aid of a general or vascular surgeon.
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Risks of this procedure include significant and brisk bleeding from the fractured vertebra, epidural veins, and major vessel injury. Ensure blood products are available, and consider use of a cell saver unless contraindicated owing to infection or tumor. Pursue a thorough preoperative medical evaluation and medical optimization for comorbid conditions.
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Consider the bony and ligamentous stability of the posterior elements of the spine, and plan appropriately for necessary adjunctive or alternative procedures for placement of instrumentation posteriorly.
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Consider preoperative embolization of particularly vascular lesions.
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Preoperative imaging should include (1) plain anteroposterior and lateral radiographs; (2) magnetic resonance imaging (MRI) for defining the neural anatomy and extent of spinal cord compression, with contrast agent to aid visualization of tumor or abscess; and (3) noncontrast computed tomography (CT) for definition of the bony anatomy for measurement and planning of instrumentation. Take care to correlate anteroposterior and lateral radiographs with other imaging modalities so that the level of pathology can be localized on intraoperative radiographs alone. Additionally, imaging of the vascular structures, such as the aorta, vena cava, and artery of Adamkiewicz, may be helpful in preoperative planning of the approach.
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Intraoperative fluoroscopy should be used, along with a compatible operating table. Ensure the fluoroscopic machines can fit around the patient in position on the table to provide anteroposterior and lateral views of the target levels.
Figure 75-1:
Left-sided approach. 1, Position the patient laterally, left side up. 2, Place beanbag or gel rolls to support the body. 3, Place an axillary roll. 4, Secure the patient with padded 3-inch tape across the shoulder and greater trochanter. 5, Flex the left hip to relax the ipsilateral psoas but not so much as to interfere with dissection. 6, Prepare and drape the patient broadly so that the anterior to posterior midline is within the field. Prepare the iliac crest if it is to be harvested.
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Plan the incision with fluoroscopy. The level of incision varies depending on the level of pathology and planned instrumentation. Fluoroscopy should be used to aid in localization and planning before incision, with the planned incision centered lateral to the vertebrae to be exposed. For levels at the thoracolumbar junction, in principle, a rib directly lateral in the midaxillary line to the pathologic vertebra is the best rib to resect for optimal exposure. In the exposure of L1, incision may extend to the level of the 10th rib.
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At the appropriate level, incise obliquely from the lateral border of the rectus muscle to the lateral border of the paravertebral musculature.
Planning and positioning
- •
The focus here is on the anterolateral-retroperitoneal approach to a lumbar corpectomy and fusion. There are several options for approaching the anterior lumbar spine, including (1) anterolateral-retroperitoneal with the patient in a lateral position, (2) endoscopic anterolateral-retroperitoneal, (3) anterior-retroperitoneal with the patient supine, (4) anterior-transperitoneal with the patient supine, and (5) lateral extracavitary with the patient in a lateral position. All approaches require special consideration of the anatomy of the ribs and diaphragm for exposure of L2 and above. Lateral approaches require special consideration of the anatomy of the iliac crest for exposure of L5 and below.
- •
Although a left-sided approach is generally preferred, important exceptions include predominantly right-sided pathology and cases of abdominal aortic aneurysm, calcifications, or other aortic disease that impairs safe mobilization of the aorta. A right-sided approach is difficult because of retraction of the liver and the dangers of retracting the thin-walled inferior vena cava.
- •
The approach to the anterior spine with requisite mobilization of the great vessels is frequently performed with the aid of a general or vascular surgeon.
- •
Risks of this procedure include significant and brisk bleeding from the fractured vertebra, epidural veins, and major vessel injury. Ensure blood products are available, and consider use of a cell saver unless contraindicated owing to infection or tumor. Pursue a thorough preoperative medical evaluation and medical optimization for comorbid conditions.
- •
Consider the bony and ligamentous stability of the posterior elements of the spine, and plan appropriately for necessary adjunctive or alternative procedures for placement of instrumentation posteriorly.
- •
Consider preoperative embolization of particularly vascular lesions.
- •
Preoperative imaging should include (1) plain anteroposterior and lateral radiographs; (2) magnetic resonance imaging (MRI) for defining the neural anatomy and extent of spinal cord compression, with contrast agent to aid visualization of tumor or abscess; and (3) noncontrast computed tomography (CT) for definition of the bony anatomy for measurement and planning of instrumentation. Take care to correlate anteroposterior and lateral radiographs with other imaging modalities so that the level of pathology can be localized on intraoperative radiographs alone. Additionally, imaging of the vascular structures, such as the aorta, vena cava, and artery of Adamkiewicz, may be helpful in preoperative planning of the approach.
- •
Intraoperative fluoroscopy should be used, along with a compatible operating table. Ensure the fluoroscopic machines can fit around the patient in position on the table to provide anteroposterior and lateral views of the target levels.
