MATERIAL and METHODS: This retrospective single-center study included 60 patients. Among them, 36 who previously had microdiscectomy underwent revisional FEID (MD group), and 24 who previously had FEID underwent revisional FEID (FEID group). In addition to general parameters, the following measurement tools were used: visual analog scale (VAS) and Oswestry disability index (ODI) questionnaire.

RESULTS: No statistically significant difference was observed in length of hospitalization, time to return to work, complications, and recurrences between the two groups. Both the FEID and MD groups had a significant decrease in postoperative VAS and ODI scores. The mean operation time was shorter in the FEID group than in the MD group, and the result was significantly different (p < 0.05). During the 36-month follow-up, no significant differences were observed in postoperative VAS and ODI scores between the two groups. Moreover, none of the patients developed complications correlated to surgery. However, three patients with a previous history of microdiscectomy or endoscopic discectomy had recurrence despite revisional endoscopic surgery.

CONCLUSION: Percutaneous revisional full endoscopic lumbar disc surgery is a safe and effective procedure that does not cause additional structural damage. Full endoscopic technique can be used safely for recurrent disc herniations regardless if a patient underwent microscopic or endoscopic surgery. Keywords : Endoscopic discectomy, Interlaminar discectomy, Recurrent lumbar disc herniation, Lumbar microdiscectomy, Minimally invasive spine surgery