Modified surgical techniques in total en bloc spondylectomy for thoracic and lumbar tumors with a single posterior approach

Abstract

Objective To investigate the operation key points, instrument improvement and shortterm effects in total en bloc spondylectomy （TES） via a single posterior approach for thoracic and lumbar tumors. Methods A series of modified instruments have been designed for the TES, including threadwire saw （T-saw） with a diameter of 0.81 mm, director and clamping for the saw, L shape and furcation osteotomes.The corpectomy of original TES which was defined as ＂one step dissection＂ from anteriorly to posteriorly, was modified into ＂two step dissection＂ which means that corpectomy was performed with saw cutting anteriorposteriorly and the L shape cutting posterior-anteriorly. In the cases with difficulty in pediculotomy using a T-saw, furcation osteotome was used for pediculotomy. Ten patients with thoracic or lumbar tumors were treated with the modified TES. There were 1 case of bone giant cell tumor, 1 case of bone neurilemmoma and 8 cases of metastatic tumors. All patients suffered moderate-severe pain and neurological deficit. Results The average follow-up period was 8.1（3.3-18.1） months. The average operating time was 7.8 h（6.0-10.3 h）,and average blood loss was 2100 ml （1200-3500 ml）. No disruption of dural mater, the leakage of cerebrospinal fluid, iatrogenic spinal cord injury and major vessel damage occurred. Two patients who underwent pleura disruption happened during the operation were treated with intrathoracic drain remedy. Among 7 cases with thoracic tumors, significant improvement in neurological function were achieved in 5 patients with the improvement of one grade in ASIA classification, while no change was found in 2 cases. In 3 cases with lumbar tumor, lumbar nerve root pain relieved and the muscle strength had recovered to grade 4 at least postoperatively. Conclusion Significant improvement has been achieved in the maneuverability and safety of the modified surgical techniques in TES with a single posterior approach for thoracic and lumbar tumors. Key words: Thoracic vertebrae; Lumbar vertebrae; Spinal neoplasms; Surgical procedures, operative