Surgical Outcome of Extreme Lateral Transforaminal Endoscopic Discectomy in the Herniated Lumbar Disc

ABSTRACT

OBJECTIVE: This retrospective study of 101 patients with symptomatic lumbar disc herniation (LDH) treated via percutaneous endoscopic surgery using the extreme lateral transforaminal approach (ELTFA) was performed to assess the clinical results and to determine the relationship between the location of the herniated disc fragment and surgical success. METHODS: The operated levels were distributed as one case of L2-3, ten cases of L3-4, 83 cases of L4-5 and seven cases of L5-6. The clinical outcomes were assessed using visual analogue pain (VAS), Oswestry disability index (ODI) and MacNab's criteria. All assessments were performed one day prior to the operation, as well as three days and one month after the operation. RESULTS: Mean preoperative back VAS (4.33+/-1.48) and leg VAS (6.29+/-2.72) were significantly decreased three days (1.43+/-1.48, 2.03+/-1.98, respectively) and one month (1.23+/-1.25, 1.89+/-1.72, respectively) postoperatively. Mean preoperative ODI score was improved from 45.86+/-20.44% to 18.92+/-12.98% after three days and to 16.34+/-9.86% one month after operation. Twenty-three patients showed a vertical migration of the herniated disc of greater than 4 mm. There was no statistically significant difference between the extents of improvement in VAS or ODI score or between the degrees of vertical migration. According to MacNab's criteria assessment, the overall surgical success rate, as measured by surgeries classified as "excellent" and "good," was 89.8%. Surgical complications included seven patients with transient leg paresthesia, one patient with transient motor weakness and one patient with postoperative discitis. CONCLUSION: This study demonstrates that percutaneous endoscopic surgery using ELTFA is an effective surgical endoscopic approach for selected LDH patients. This procedure is safe and could expand indications to vertically migrated discs.