Full-endoscopy with intraoperative O-arm navigation for cervicothoracic gas-containing hemorrhagic synovial cyst: A case report

Background: Synovial cysts are benign fluid-filled sacs commonly found in the degenerative lumbar spine. Few studies have reported the detailed epidemiology and standardized therapy for this disease. Conservative treatment is recommended if synovial cysts are asymptomatic or show mild clinical symptoms. If percutaneous facet joint steroid injections are ineffective or neurologic symptoms are aggravated, the open decompression with additional fusion is the reasonable surgical strategy to remove the pain generator. Furthermore, the synovial cysts that occur at the cervicothoracic spine are infrequently, especially accompanied by hemorrhagic radiographic evidence. Therefore, we describe the efficacy and safety of the full-endoscopy surgical procedure assisted by intraoperative O-arm navigation guidance to manage C7/T1 spinal synovial cysts. Case description: We describe a 71-year-old male patient diagnosed with cervicothoracic hemorrhagic synovial cysts. The pathologic site is located at the posterior side of the C7 vertebral body to the medial side of the C7-T1 left facet joint. Herein is described a step-by-step protocol for the full-endoscopic procedure via the posterior approach to remove the lesions under intraoperative O-arm navigation guidance. Outcome: The patient was successfully treated via full-endoscopic removal of the synovial cysts guided by intraoperative O-arm navigation. Intraoperative bleeding of 30 mL occurred, and the operative time was 150 minutes. The patient's sensory strength improved, and no opioid medicine was required with no complications postoperatively. One-year follow-up magnetic resonance imaging (MRI) and computed tomography (CT) scans showed no synovial cyst recurrence. Conclusions: Full-endoscopy assisted with intraoperative O-arm navigation guidance improves precision and safety in treating patients with synovial cysts of the cervicothoracic spine. The O-arm navigation system improves the efficiency and safety of intraoperative positioning at the cervicothoracic lesion and reduces radiation exposure to the surgeons. Meanwhile, this technique preserves the range of cervicothoracic motion and facilitates the patient return to normal life.