"U" route transforaminal percutaneous endoscopic thoracic discectomy as a new treatment for thoracic spinal stenosis

To describe the rationale, surgical technique, and short-term follow-up results of a new minimally invasive treatment for thoracic spinal stenosis (TSS) caused by herniation, ossification of the ligamentum flavum (OLF), and/or ossification of the posterior longitudinal ligament (OPLL) with a "U" route transforaminal percutaneous endoscopic thoracic discectomy (PETD).

Fourteen patients, including seven males and seven females, underwent "U" route PETD. Myelopathy was caused by OLF in 14 patients, OPLL in one, combined OLF-OPLL in ten, and intervertebral disc herniation (IDH) in five. Decompression was performed in one segment in 12 patients, and in two segments in two patients. The Japanese Orthopedic Association (JOA) scores, visual analog scale (VAS) scores, and complications were documented.

The JOA scores improved from 4.64 ± 2.31 pre-operatively to 7.07 ± 1.59 one day post-operatively and 11.79 ± 1.85 at final follow-up. The difference between pre-operation and post-operation was statistically significant (P < 0.05). Moreover, the VAS score was 6.07 ± 2.06 points pre-operatively, decreasing to 3.00 ± 1.24 points at one day post-operatively, and 1.14 ± 0.86 points at last follow-up (P < 0.05). Dural tear was observed in two cases during the intervention. No patient had transient worsening of pre-operative paralysis.

This retrospective analysis shows that "U" route PETD for decompression may be a feasible alternative to treat thoracic spinal stenosis.