Primary Spine Tumors: Diagnosis and Treatment

Michelle J. Clarke, MD; Ehud Mendel, MD; Frank D. Vrionis, MD, PhD

Disclosures

Cancer Control. 2014;21(2):114-123. 

In This Article

Surgical Staging

Once the preferred method of resection has been determined, patients must be surgically staged to determine the technical feasibility of the procedure. Invasiveness into nearby unresectable structures is the primary reason some tumors, particularly in the case of sarcomas, are unresectable in en bloc fashion and may rely on debulking with adjuvant therapy. In all other cases, other systems have been proposed,[18,25] but the determination must be whether a surgical corridor exists in order to deliver the tumor in 1 piece without disrupting vital structures. Oftentimes, the limiting factor for determining the tumor trajectory is the spinal cord, which is encircled by a bony wall composed of vertebral body, pedicles, and lamina. To remove a tumor specimen en bloc, the ring must be broken wide enough to pass around the spinal cord. Thus, if the tumor completely encircles the spinal cord, a marginal en bloc resection is not possible without violating the tumor. The break in the ring also determines the surgical corridor for tumor removal; it must be removed opposite the break in the ring. Thus, immobile vital structures beyond the spinal column may preclude removal. Nearby structures, such as the great vessels and heart, may limit the resectability of a tumor or increase the difficulty of the procedure.

Generally, location on the spinal axis predicts the technical difficulty associated with en bloc resection and reconstruction; surgery is more challenging from the sacrum to clivus. Distal sacrectomies may be accomplished using a posterior-only approach. Mid to upper sacrectomies may involve the posterior-only or the anterior and posterior approach to aid dissection and utilize rectus vascularized flaps to aid in closure. Total sacrectomies, in which S1 is removed, require instrumented reconstruction. In the lumbar spine, the great vessels, renal arteries, ureters, and digestive structures must be considered, as well as nerves involved in lower extremity function. In the thoracic spine, mediastinal structures preclude certain surgical trajectories, and chest wall reconstruction may be indicated. The subaxial cervical spine may be challenging because upper extremity and diaphragmatic innervation, the vertebral arteries, trachea, and esophagus are in close proximity. However, high cervical spine and clival lesions are challenging because transoral and transmandibular approaches may be required. In these cases, cranial nerves and vascular structures make resection difficult. Fig 4 outlines the overall surgical strategy.

Figure 4.

A diagnostic and treatment algorithm for primary tumors is illustrated, including a specific approach for malignant histologies. GTR = gross-total resection, ILR = intralesional resection, OpenBx = open biopsy.

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