20 Vertebral Corpectomy for Thoracic Tumor or Infection 1. To decompress the spinal cord, reduce tumor bulk, stabilize the spine, and confirm diagnosis and staging in unresectable tumors 2. To achieve curative, en bloc excision in isolated resectable tumors Pain and weakness are the most common presenting complaints in both thoracic tumors and infection. Pain is usually constant and unremitting, worse at night, and segmental in location. Radicular symptoms may result in “girdle” pain in the thoracic spine or mimic herniated nucleus pulposus in the lumbar segments. Neurologic deficits are rarely the first symptoms to present, but are common by the time the diagnosis is made. Examination occasionally reveals spinal deformity or mass. Plain films show bone destruction, including the classic “winking-owl” sign, when bone loss of 30 to 50 % is present. Technetium-99 m bone scans are very sensitive, but not specific. Computed tomography (CT) scans and CT myelograms offer improved sensitivity and accuracy. When CT scans show destruction of more than 40 % of the vertebral body, there is an 80 to 90 % chance of vertebral collapse. Magnetic resonance imaging (MRI) is the gold standard imaging study for detecting spinal neoplasms and for evaluating neural compromise and soft tissue mass. Sclerotic tumors give low-intensity signals on T1- and T2-weighted images, whereas lytic lesions give lowintensity signals on T1- and high-intensity signals on T2-weighted images. MRI also provides the most definitive imaging of vertebral osteomyelitis or abscess. Biopsy is the last step in preoperative diagnosis and staging. Although some posterior lesions may be amenable to excisional biopsy, most lesions require either needle or an incisional biopsy. Biopsies should be performed by the surgeon who will do the definitive excision, and should take into account future incisions needed for definitive surgery. Transverse incisions must be avoided. Surgery is considered in those with at least 6 weeks‘ life expectancy with the following: 1. Severe, unremitting pain 2. Progressive neurodeficits in the face of, or following, appropriate radiation therapy 3. Instability or progressive deformity of the spine 4. Unknown histologic diagnosis 5. Pathologic fracture of the spine, with bony compression of neural elements 6. Isolated lesion or solitary site of relapse offering hope of extended survival 1. Very limited life expectancy (i.e., less than 6 weeks) 2. Diffuse spinal involvement 3. Compromised medical status 4. Lack of facilities/resources for definitive management Choice of procedure is determined by location of tumor or lesion (Fig. 20–1) (McLain and Weinstein, 1990, 1999). Zone I lesions are best approached posteriorly; zone II lesions can be approached either posteriorly or posterolaterally; zone III lesions should be approached anteriorly; and zone IV lesions require a combined anterior and posterior approach for complete excision. The video-assisted transpedicular approach is indicated for: 1. Intralesional resection of thoracic spinal metastasis causing cord compromise and instability 2. Debridement and stabilization of radiosensitive tumors 3. Decompression and stabilization of spine infections This approach is particularly useful for tumors of the upper thoracic spine (T1-T4), and for patients with established pulmonary disease who cannot tolerate thoracotomy (McLain, 1998). It provides extrapleural access to the thoracic vertebral body for intralesional vertebrectomy. Position the patient prone, and make a midline longitudinal incision centered over the spinous processes at the appropriate level. Dissect the paraspinal muscles off the spine and transverse processes and retract them laterally. The costotransverse ligaments are divided, the rib excised lateral to the vertebral body, and the transverse process resected close to its junction with the lamina. The pedicle lies anterior to the stump of the resected transverse process, with the neural foramina above and below. Below the transverse process and medial to superior costotransverse ligaments are vessels that should be cauterized or tied. After costotranversectomy the pedicle is taken down flush with the vertebral body using a bur and rongeurs. Progressively debulk the anterior tumor under direct vision to create a cavity within the vertebral body. Introduce the 30-degree, 4-mm endoscope into the cavity to help visualize the posterior vertebral cortex, posterior longitudinal ligament, and dura, thereby ensuring safe and complete decompression (Fig. 20–2
Goals of Surgical Treatment
Diagnosis
Indications for Surgery
Contraindications to Surgery
Procedure
Video-Assisted Posterolateral Approach
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
