Foraminoplastic Ventral Epidural Approach for Removal of Extruded Herniated Fragment at the L5-S1 Level

Abstract

The 'foraminoplastic' ventral epidural approach and its advantages in the treatment of extruded disk herniation at the L5-S1 level are described. Percutaneous endoscopic lumbar discectomy is a minimally invasive procedure applicable to various types of lumbar disk herniation, but the L5-S1 disk space is still challenging to access due to anatomic limitations such as high iliac crest or severely narrowed foramen. The 'foraminoplastic' ventral epidural approach was performed in 25 patients with herniated disk radiculopathy at L5-S1 from March 2003 to May 2004. Their mean age was 39.2 years (range 20-67 years) and the mean follow-up duration was 32.5 months (range 28-42 months). During the procedure, 'foraminoplasty' was performed by undercutting the hypertrophic superior facet with the endoscopic bone cutter under C-arm guidance. The clinical result was assessed according to the visual analogue scale (VAS) and Oswestry disability index (ODI). Preoperative mean VAS score of 7.4 for leg pain fell to 1.6 postoperatively and mean preoperative ODI of 55.5% improved to 16.9% postoperatively, both showing significant improvements (p < 0.001). Mean hospital stay was 14.2 hours. Twenty-two patients had the favorable outcomes. Two patients required conversion to open microdiscectomy due to incomplete decompression and recurrent disk herniation. The 'foraminoplastic' approach is a safe and efficient surgical option for L5-S1 disk herniation even in patients with high iliac crest and narrow foramen.