Endoscopic Ventral Decompression for Spinal Stenosis with Degenerative Spondylolisthesis by Partially Removing Posterosuperior Margin Underneath the Slipping Vertebral Body: Technical Note and Outcome Evaluation

BACKGROUND: Decompression alone is a treatment option in patients with lumbar spinal stenosis (LSS) and degenerative lumbar spondylolisthesis (DLS). This study aims to describe the procedure of percutaneous transforaminal endoscopic ventral decompression technique and to demonstrate the clinical outcomes. METHODS: Two years of retrospective data were collected from 26 patients with predominant unilateral leg pain caused by LSS and low-grade DLS (Meyerding grades I and II). All patients underwent endoscopic ventral decompression by removing the posterosuperior margin underneath the slipping vertebral body, combined with dorsal decompression without excessive resection of facet joints. The surgical outcomes were assessed using the visual analog scale (VAS), Oswestry Disability Index (ODI), modified MacNab criteria, and walking distance improvement evaluation. RESULTS: The mean age of the 18 women and 8 men was 69.2 years. The mean preoperative ODI and VAS of the leg and the back scores were 64.7 +/- 8.1, 7.0 +/- 1.4, and 3.0 +/- 1.2, respectively. All mean scores improved postoperatively to 31.4 +/- 5.6, 2.4 +/- 1.1, and 1.7 +/- 1.1 at the final follow-up. In 88.5% of cases, patients' estimated walking distance improved. The outcomes of the modified MacNab criteria showed that 81.3% of patients obtained good-to-excellent rate. There were no statistically significant differences between the percent slip of spondylolisthesis before surgery and at the end of follow-up. CONCLUSIONS: Based on the initial short-term follow-up results, transforaminal endoscopic ventral decompression by partially removing the posterosuperior margin underneath the slipping vertebral body, combined with dorsal decompression, might be an efficient alternative treatment for leg dominant symptoms in patients with LSS and low-grade DLS.