Surgical management of recurrent thoracolumbar spinal sarcoma with 4-level total en bloc spondylectomy: description of technique and report of two cases.

INTRODUCTION: The descriptions of total spondylectomy and further development of the technique for the treatment of vertebral sarcomas offered for the first time the opportunity to achieve oncologically sufficient resection margins, thereby improving local tumor control and overall survival. Today, single level en bloc spondylectomies are routinely performed and discussed in the literature while only few data are available for multi-level resections. However, due to the topographic vicinity of the spinal cord and large vessels, the multisegmental resections are technically demanding, represent major surgery and only few case reports are available. Surgical options are even more limited in cases of revision surgery and local recurrences when en bloc spondylectomy was considered to be not feasible due to high risk of vital complications in expanding resection margins. Deranged anatomy, implants in situ and extensive intra-/paraspinal scar tissue formation resulting from previously performed approaches and/or radiation are considered the principal complicating factors that usually hold back spine surgeons to perform revision for resection leaving the patient to palliative treatment.
METHODS: We present two patient cases with previously performed piecemeal vertebrectomy in the thoracic spine due to a solitary high-grade spinal sarcoma. After extensive re-staging, both patients underwent a multi (4)-level en bloc spondylectomy in our department (one patient with combined en bloc lung resection). Except a local wound disturbance, there was no severe intra- or postoperative complication.
RESULTS: After multilevel en bloc spondylectomy both patients showed a good functional outcome without neurological deficits, except those resulting from oncologically scheduled resection of thoracic nerve roots. After a median follow-up of 13 months, there was no local recurrence or distant metastasis. The reconstruction using a posterior screw rod system that is interconnected to an anterior vertebral body replacement with a carbon composite cage showed no implant failure or loosening. In summary, the approach of a multilevel en bloc surgery for revision and oncologically sufficient resection in cases of spinal sarcoma recurrences seems possible. However, interdisciplinary decision making in a tumor board, realistic evaluation of surgical resectability to attain tumor free margins, advanced experiences in spinal reconstructions and involvement of vascular, visceral and thoracic surgical expertise are essential preconditions for acceptable oncological and functional outcome.