Study design: Twenty-nine patients with primary bone tumors and solitary metastases of the thoracolumbar spine treated with en bloc resection are reviewed retrospectively.
Objective: To demonstrate the possibility to apply in the spine the same principles of surgical oncology adopted for primary bone tumors of the limbs.
Summary of background data: The surgical oncologic staging systems currently applied in limb tumor surgery are difficult to apply to spinal tumors. The anatomic conditions make extralesional surgery difficult or impossible, which has restrained a more common use of resection surgery in the spine. Focus is put on a new surgical staging system and en bloc vertebral resection.
Methods: Twenty-five primary malignant and aggressive benign bone tumors and four solitary metastases were treated. The patients were submitted to oncologic and surgical staging for surgical planning. The primary tumors were classified according to Enneking system: three Stage IA, six Stage IB, eight Stage IIB, eight Stage 3 benign. Staging according to the Weinstein-Boriani-Biagini system was also done. Thirteen lesions involved the vertebral body; nine lesions developed in the posterior arch, or part of it, and seven lesions occupied part of the body and part of the arch. A careful anesthesiologic evaluation was performed as well as a continuous intraoperative on-line monitoring of the vital parameters. The en bloc resections (multisegmental in five patients) were performed in 10 thoracic, in 16 lumbar, in two thoracolumbar lesions, and in one lumbosacral lesion. Reconstruction was performed, aiming to replace the resected columns. The specimens were submitted to histologic study of the margins. All the patients were followed, and their status was defined on clinical and imaging studies.
Results: In 20 patients, a wide margin was achieved, in eight a marginal margin, in one an intralesional margin. The margin was contaminated in seven patients. Surgical time was 3-21 hours (average, 12 hours). No patient died during surgery or from surgical complications. Three mechanical failures of the implants required additional surgery. One deep infection arose. The only neurologic problems observed were related to the nerve roots sectioned for oncologic purpose. No local recurrence was found at follow-up evaluation after 6-134 months (average, 30 months).
Conclusions: En bloc resection can be performed in selected tumors of the spine; the indication to such major surgery must be based on the oncologic stage, and the procedure must be carefully planned. For this purpose, the Weinstein-Boriani-Biagini system could be a helpful tool. Long-term results must be weighed before a definitive statement of the indications can be made.