Feasibility of interlaminar lumbar discectomy through percutaneous transforaminal endoscopy and blunt perforation of the ligamentum flavum.

AIM To determine the efficacy, safety, and clinical value of a novel surgical procedure involving the blunt perforation of the ligamentum flavum (LF) during endoscopic interlaminar lumbar discectomy. MATERIAL AND METHODS This was a prospective study of 50 patients (27 males, 17-51 years of age) undergoing lumbar discectomy for single segment L4/L5 or L5/S1 disk herniation were grouped into the control (cutting of the LF; n=28) and test (blunt perforation; n=22) groups. Intraoperative injury to the LF was evaluated by electrophysiological monitoring. The time required for perforation, total surgical time, and proportion of epidural sac and nerve root injury were assessed. RESULTS Among the enrolled patients, 90% showed herniation of the L4/5 segment and 10% of the L5/S1 segment. The success rate for the perforation of the LF was 93%. The intraoperative observation showed mild self-closing injury to the LF tissue. The test group showed shorter overall surgical time (43 vs. 56 min) and shorter duration to go through the LF (1 vs. 13 min, p 0.001). No dural sac or nerve root injury resulting from blunt perforation of the LF was observed. CONCLUSION Compared to cutting, blunt perforation of the LF could reduce surgical time and injury to LF and surrounding tissues. Thus, it could be a safe and efficient surgical technique for patients undergoing intralaminar lumbar discectomy.