Percutaneous Endoscopic Lumbar Discectomy as an Alternative to Open Lumbar Microdiscectomy for Large Lumbar Disc Herniation

Background: Remarkable advancements in endoscopic spinal surgery have led to successfuloutcomes comparable to those of conventional open surgery. Large lumbar disc herniation (LLDH)is a serious condition, resulting in higher surgical failure when accessing the herniated disc.Objectives: This study compared the outcomes of LLDH treated with percutaneous endoscopiclumbar discectomy (PELD) and open lumbar microdiscectomy (OLM).Study Design: Retrospective assessment.Methods: This retrospective observational study was conducted from January 2011 to June2012. Forty-four consecutive patients diagnosed with LLDH without cauda equina syndrome whowere scheduled to undergo spinal surgery were included. LLDH was defined as herniated discfragment occupying > 50% of the spinal canal. Clinical outcomes were evaluated using a visualanalogue scale (VAS, 0 – 10), functional status was assessed using the Oswestry Disability Index(ODI, 0 – 100%) at 1, 6, and 24 months postoperatively and surgical satisfaction rate (0 – 100%)at final follow up. Radiological variables were assessed by plain radiography.Results: Forty-three patients were included; 20 and 23 patients underwent PELD and OLM,respectively. Both groups exhibited significant improvements in leg and back pain postoperatively(P < 0.001). Although there was no significant difference in leg pain improvement between thegroups, improvement in back pain was significantly higher in the PELD group than in the OLMgroup (4.9 ± 1.5 vs. 2.5 ± 1.0, P < 0.001). The surgical satisfaction rate of the PELD group wassignificantly higher than that of the OLM group (91.3% ± 6.5 vs. 84.3% ± 5.2, P < 0.001). Meanoperating time, hospital stay, and time until return to work were significantly shorter in the PELDgroup than in the OLM group (67.8 vs. 136.7 minutes, 1.5 vs. 7.2 days, and 4.2 vs. 8.6 weeks;P < 0.001). Disc height (%) decreased significantly from 23.7 ± 3.3 to 19.1 ± 3.7 after OLM (P< 0.001), but did not change significantly after PELD (23.6 ± 3.2 to 23.4 ± 4.2; P = 0.703). Thesegmental angle of the operated level increased from 10.3° to 15.4° in the PELD group, which wassignificantly higher than that in the OLM group (9.6° to 11.6°; P = 0.038). In the OLM group, therewas one case of fusion due to instability. In the PELD group, one case required revision surgery andanother case experienced recurrence. There were no perioperative complications in either group.Limitation: The study was retrospective with a small sample size and short follow-up period.Conclusion: PELD can be an effective treatment for LLDH, and it is associated with potentialadvantages, including a rapid recovery, improvements in back pain, and disc height preservation.Key words: Large lumbar disc herniation, percutaneous endoscopic lumbar discectomy,microdiscectomy, back pain, disc height