[Clinical efficacy of resection of extramedullary subdural tumor in thoracic spinal canal via muscle-pedicle open-door laminoplasty approach].

In order to evaluate the efficacy of resecting extramedullary subdural tumors, located in the thoracic spinal canal, via the muscle-pedicle open-door laminoplasty approach, clinical data of fifteen patients with thoracic spinal tumors admitted to the Department of Spinal Surgery in the Affiliated Hospital of Qingdao University from December 2018 to June 2021 were analyzed retrospectively. All patients received surgical treatment to remove the tumors via the muscle-pedicle open-door laminoplasty approach. The clinical data of the patient was recorded. The Japanese Orthopedic Association (JOA) score, the thoracic kyphosis angle in the standing position before and after the operation, and the visual analog score (VAS) of thoracic back incision pain before and after the operation were compared. CT scan was performed three months after the surgery and at the last follow-up to measure the healing of the lamina. In addition, MRI was used to detect the healing of the posterior ligament at the last follow-up. The tumors of all fifteen patients were completely removed, the operating time was (91±15) minutes, blood loss was (117±56) ml. Cerebral spinal fluid leakage occurred in three patients, but the incisions healed smoothly following compression and no complication was observed. All patients were followed-ups for more than 6 months. The VAS score of thoracic back incision pain was (3±1.3) points at three days post operation and it dropped to (1.3±0.9) points three months post-operation. The JOA score improved significantly after the operation, it was (11.9±2.4) points before operation, and it was (14.0±1.6) points three months post operation and increased to (16.1±0.7) points at the last follow-up (both P <0.001). The Cobb angle was 10.1°±5.3° before the operation and it was 10.4°±6.2° at the last follow-up ( P =0.420). Three months after operation, partial callus formation or even complete healing on the muscle pedicle side was observed on the CT scans of all patients. At the last follow-up, CT scans showed complete healing on the muscle pedicle side. There were different degrees of sclerosis and healing on the open-door side. There was no necrosis, displacement, or secondary spinal canal stenosis in any vertebral lamina. It indicated that the muscle-pedicle open-door laminoplasty approach is an effective way to resection extramedullary subdural tumors located in the thoracic spinal canal.