Introduction: The full endoscopic interlaminar approach (FEILA) is a minimally invasive procedure to treat intracanal lumbar disc herniation not approachable by endoscopic transforaminal access. Disc prolapses have been classified into three categories according to their position and passing nerve root displacement: (i) type A, in which the nerve root is displaced medially; (ii) type B, in which the nerve root is displaced laterally; and (iii) type C, in which the nerve root is ventrally displaced. We focused on the FEILA technique because it was likely to involve few complications and that provided the advantages of the endoscopic approach.
Methods: We prospectively evaluated 100 consecutive cases of L5-S1 disc herniations operated on with FEILA, including 85 type A cases, 13 type B, and 2 type C. Patients were evaluated at discharge, 3 months, 6 months and 2 years.
Results: The operating time varied from 15 to 40 min. The use of drills and burrs was necessary to treat type B disc herniations; thus, it was preferable that these cases were operated on later in the learning curve. After surgery, 90% of neurological deficits improved. The Oswestry Disability Index and visual analog scale leg at last follow-up were 15 and 9, respectively. There were no major complications. There were five cases of recurrence; four of which were treated with same technique and with good results.
Conclusion: FEILA is a safe procedure for the removal of intracanal L5-S1 disc herniations. The late follow-up confirms the stability of the results. We suggest treating type A prolapse at the beginning of the learning curve and type B herniations after sufficient experience in the use of the burrs has been achieved.
Keywords: Disc herniation; endoscopic lumbar surgery; interlaminar approach.
© 2015 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and Wiley Publishing Asia Pty Ltd.