Case Report: Multilevel spondylectomy for en bloc resection of an upper cervical chordoma: surgical technique and conceptualization through the CLiMR framework.

Introduction: Spinal chordomas are locally aggressive primary malignancies of bone that require en bloc surgical resection to optimize outcomes. A rare subset of spinal chordomas occur in the cervical spine, some of which involve the upper cervical spine and craniovertebral junction (CVJ). These tumors require highly complicated and risk-prone surgeries. We report the case of a high-cervical chordoma which was resected en bloc via a three-stage surgical procedure and characterize the case through the novel CLiMR (Column, Line-of-Sight, Margins, Ring) framework for en bloc spondylectomies. Case description: A 66-year-old male presented with right-sided neck and facial pain. He was found to have a chordoma originating from C2 involving both C3 and the craniovertebral junction. He underwent a posterior-anterior-posterior three-stage surgical resection under the same anesthesia, which lasted approximately 29 hours. Postoperatively, he required prolonged ventilator weaning but is recurrence free and full strength at over two years of follow-up. The CLiMR score for this case was 15.5, which is an exceptionally high score and underscores the anatomic and procedural complexities inherent to the CVJ. Conclusion: We present the successful en bloc resection of an upper-cervical chordoma as performed through a three-stage operative case. The CLiMR system can provide a standardized tool for operative characterization and risk communication, which can aid in the planning and execution of complex spinal oncology cases.