TES which provides the best chance of local and system control for primary spinal malignant tumors has been developed for many years. With the help of modern techniques, wide surgical margin could be expected in some patients receiving spinal tumor surgery. In a review [1] of 103 patients affected by primary spinal tumors, the rate of achieving adequate margins was 82.4%, whereas local recurrence occurrence rate was 21.4% (22 patients). Marginal and intralesional resections were independent predictors for local recurrence and tumor-related mortality (15.5%). When tumors involve more than one vertebra, multilevel TES can provide satisfactory oncological prognosis. In a study [9] including 20 patients who received multilevel (2–5 segments) en bloc spondylectomy of the thoracolumbar spine, wide and marginal surgical margins were achieved in all patients. With a mean follow-up of 25.0 months, one patient had local recurrence, whereas two patients died of systemic disease. In another study [10] of multilevel spondylectomy for spine tumors, the local recurrence rate was 8, and 81% of patients survived without evidence of the disease at the final follow-up.
In order to achieve satisfied surgical margins for spinal tumor resection, different approaches are recommended according to the scope of tumor invasion. Boriani et al. [7] have proposed four kinds of approaches (types) for en bloc resection of thoracic spine tumors: anterior approach, posterior approach, anterior approach first and posterior approach second, and posterior first and simultaneous anterior and posterior approach second. Among them, Type 4 resection is more suitable when the tumor is particularly huge and it is presumed that the resection can require complex maneuvers. Therefore, combined anterior and posterior approach should be considered in this patient. Because the upper thoracic spine remains an extremely difficult region to approach anteriorly (proximity of the mediastinal contents, the heart, and the great vessels), different approaches to the cervical thoracic junction including low cervical approach combined with sternotomy [11], unilateral or bilateral manubriotomy [12], or with clavicular dissection [13] have been reported. The anterior exposure of tumor with large diameter involving upper thoracic spine could be even more complex, and additional lateral parascapular thoracotomy may be considered. Siubba et al. [14] reported of a 5-level spondylectomy (T1–5) for en bloc resection of an extensive thoracic chordoma via a bilateral thoractomy. In our case, for the tumor which involved left thoracic cavity and chest wall had even bigger volume when compared with Siubba’s, a “Trap door” incision combined with left parascapular thoracotomy were adopted for better anterior exposure.
With aggressive multilevel TES, a large spinal column defect is created and needs effective anterior spinal column reconstructions. Widely used anterior reconstruction techniques include vascularized autograft strut, nonvascularized autograft strut, titanium cage, stackable carbon cage system, structural allograft strut, and PMMA [15]. All these methods have advantages and deficiencies. For example, mesh cages filled with granular bone grafts have a high incidence of subsidence; the expandable cage has the disadvantages of insufficient amount of bone graft and limitation of using in extensive spinal column reconstruction; vascularized autograft has shortcomings of donor site morbidity and time consumption of vascular anastomosis. Therefore, a 3D-printed modular vertebral prosthesis assembled during operation was adopted for this patient. The prosthesis has variable combinations of length, diameter, and degree of curvature to fit different needs of vertebral reconstruction.
In addition to spinal defect, this patient had also faced to the problem of large area of chest wall reconstruction. For patients with multi-level thoracic spinal tumors involving huge rib cage, large area of chest wall defects could cause severe respiratory complications, such as paradoxical chest wall movement and respiratory failure [16]. Several methods for rib cage reconstruction during operation of TES have been reported in few studies with optimal results. Czyz et al. [17] used rib plate combined with flexible polyethylene terephthalate band for chest wall reconstruction in a case of Pancoast tumor resection. Xiao et al. [18] reported five patients of multilevel TES of thoracic spine combined with large area of ribs and chest wall resection. Titanium rods used for rib reconstruction were modified accordingly to attach to the screw-rod system proximally, and the distal end of rods was dynamically inserted into the ribs. However, for the concern of complications [16] including wound infection and hardware failure, and difficulty of full length of rib rebuilding, a sandwiched bone cement plate [19] with curvature was adopted for chest wall reconstruction in our patient. It’s easily maneuvered during operation, with no complications, and allowed excellent recovery of pulmonary function.
We successfully resected a huge chondrosarcoma involving T1–5, left upper thoracic cavity, and chest wall as one piece, and the patient fully recovered his neurologic compromise eventually. Although encountered complications, en bloc tumor resection with combined surgical approach and effective reconstructions could improve oncologic and functional prognosis in carefully selected spinal tumor patients.