Phase I 270° single-incision percutaneous spinal endoscopy for decompression treatment of thoracic spinal stenosis

Abstract

This study aimed to explore the feasibility of Phase I percutaneous spinal endoscopy with a 270° single incision in the ventral and dorsal dura mater for decompression treatment of thoracic spinal stenosis (TSS). Phase I percutaneous spinal endoscopy with a two-path (posterior and posterolateral approaches) single incision with a 270° decompression was performed in four cases of TSS with compression in the ventral and dorsal dura mater. The affected intervertebral space was located during the surgery, and the ossified ligamentum flavum in the ventral and dorsal dura mater was removed via laminectomy, which formed a decompression space in the thoracic cord. Next, posterolateral transforaminal expansion and plasty were performed to remove the ventral intervertebral disk. The visual analogue scale (VAS) score, thoracic spinal cord function score of the Japanese Orthopaedic Association (JOA) (11-point method), and Oswestry Disability Index (ODI) scores were used to evaluate the clinical efficacy. No dura mater or thoracic nerve injury occurred during the surgery. The symptoms of weakness in the lower extremities improved after the surgery. The postoperative magnetic resonance imaging and computed tomography examinations showed compression removal and dura mater bulging. The postoperative VAS, JOA, and ODI scores improved compared with the preoperative scores. Two surgical trajectories, posterior and posterolateral approaches, were established by a single incision using thoracic spinal canal decompression with Phase I 270° single-incision percutaneous spinal endoscopy. The posterior approach was performed mainly by translaminar unilateral fenestration and bilateral decompression in the ventral and dorsal dura mater, whereas the posterolateral approach was performed by decompression in the ventral dura mater to the midline of the vertebrae. This surgical method could be applied as a safe and feasible minimally invasive treatment for TSS with compression on both the ventral and dorsal dura mater.

Figure 1

Illustration of the critical process in 270° decompression technique of spinal endoscopy. (A) The window of the posterior approach vertebral plate was opened. First, contralateral decompression was performed and then ipsilateral decompression was performed. (B) The posterolateral approach was used to remove the ventral disc and part of the vertebral bone; (C) The percutaneous spine endoscopic technique accomplished phase I compression in the ventral and dorsal dura mater using 270° decompression.

Figure 2

Typical cases. (A–C) Preoperative CT and MRI examinations showed T_10/11 disk herniation on the left side with ossification of the ligamentum flavum and thoracic spinal cord degeneration in the corresponding segment. (D) Dura mater exposure after decompression via the posterior approach. (E) Dura mater margin exposure under decompression via the posterolateral approach. (F–I) Postoperative CT and MR showed that the disc herniated, the ossified ligamentum flavum was removed, and there was no compression in the dura mater.