Although the best chance for cure (local recurrence, disease-free survival) of aggressive benign and malignant tumors of the spine is realized through a wide en bloc resection, the surgical technique is demanding and not yet standardized. Usually the surgical procedure includes a staged removal of the tumor with a healthy soft-tissue cover as a barrier and an adequate reconstruction. Three different types of en bloc resection of the spine can be identified: en bloc resection of the dorsal elements, a sagittal en bloc resection, and a total spondylectomy. To perform these resections, careful planning is mandatory and consists of an adequate oncologic and surgical staging of the tumor, choosing of appropriate surgical approaches and techniques, and the use of optimal reconstruction materials and spinal-fixation systems. Principles of wide en bloc surgical resection should be applied to primary aggressive benign and malignant spinal tumors, and some selected secondary malignant tumors of the spine with anticipated acceptable morbidity and satisfactory survival.

To date, adequate surgical intervention in combination with multimodal therapy are the cornerstones for the treatment of primary aggressive benign and malignant tumors, some secondary malignant tumors arising in the extremities and the pelvis, and also in the spine. However, the topographic vicinity of vital organs, vessels, and neural structures to the vertebral column profoundly complicates the management of these tumors with respect to planning, surgical procedure, and reconstruction. To reduce the tumor spillage and spread during surgery, the chance of local recurrence, and to improve the survival time, an algorithm has been developed to map the tumor adequately, to choose the optimal surgical approach and surgical techniques, and to perform a sound reconstruction. Equally important is the careful pre- and postoperative care and choice of adjuvant treatment.

Usually the investigation starts with a thorough anamnesis: pain (skeletal and/or caused by nerve root irritation) constitutes the most frequent complaint with which vertebral neoplasm is presented (1). At the onset, it is usually mild and then becomes subcontinuous and continuous, finally not depending on posture or rest. Much less frequently (less than 5%), the clinical onset is characterized by the occurrence of disorders
due to myeloradicular compression (paresthesia, hypesthesia, sphincter disorders) that are frequent in advanced stages of disease.

After conventional radiographs (at the onset often negative) and persistence of pain and/or possible occurrence of myeloradicular symptoms, additional imaging investigations [CT, magnetic resonance imaging (MRI), and/or positron emission tomography (PET) or bone scans] are initiated, which usually identifies a lesion and establishes its topographic features. Once the radiologic features of the lesion have been defined, biopsy is performed, either image-guided (CT or C-arm guided) or open.

Anamnesis, imaging, and biopsy allow appropriate terminology, classification, and choice of surgical techniques and materials to perform an en bloc resection of spinal tumors. For example, sophisticated imaging methods allow both an appropriate oncologic staging, introduced by Enneking, and the now widely used surgical staging system for the spine, the WBB system (2,5). According to the oncologic classification system of Enneking, an en bloc resection is an attempt to remove the whole tumor in one piece, together with a layer of healthy tissue (5). The specimen can be subjected to histologic analysis, and the margins can be categorized as “intralesional,” “marginal,” or “wide.” In 1997, Weinstein-Boriani-Biagini described a surgical staging system for the spine, the WBB system. It is a standardized simple aid: a vertebra is divided into 12 radiating zones, which can be used for the optimal selection of any spinal column tumor (4). In addition, sophisticated anesthesiologic, surgical techniques, and modern spinal-fixation techniques allow challenging procedures, restoring stability and avoiding severe neurologic injury.

Indications for en bloc resection of spinal tumors include aggressive benign tumors, primary malignant tumors, and isolated spinal metastases in the setting of controlled systemic disease, although the latter is controversial (2,3,17,18). Recurrent tumors previously treated unsuccessfully with surgery are also suitable for an attempt at an en bloc resection. One or more consecutive vertebrae can be removed as a single en bloc specimen. Contraindications include distant metastases, uncontrolled systemic disease, and encasement of adjacent or vascular structures that cannot be excised.

Various surgical procedures and spinal materials have been developed to perform not only multilevel posterior and/or anterior fixation but also to replace vertebral bodies (4,6,7,8,10,11,17). Based on these reports, several other surgical techniques have been described, encompassing variable indications, approaches, stabilization techniques, and yielding promising results in view of local control and overall prognosis (2,10,16,17,19). Before surgery, an outline of the surgery should be made and discussed with the participating disciplines. Quite often an interdisciplinary team consisting of general or vascular surgeons, neurosurgeons, and plastic surgeons is needed to perform the surgery. Appropriate reconstruction materials should be ordered. When a vascularized graft is used to reconstruct the osseous defect, the type of graft and the acceptor and donor vessels for anastomosis should be discussed. The same applies to free or pedunculated muscle flaps to reconstruct soft-tissue defects.

The three types of en bloc resection are a one-stage posterior resection and reconstruction when only the dorsal elements are involved; a staged surgical procedure for both a sagittal resection when the tumor occupies one side of the vertebra; and a spondylectomy or vertebrectomy when the tumor involves the vertebral body.