1. 2016;19;E1161-E1166Long-term Follow-up Results of Percutaneous Endoscopic Lumbar Discectomy
   Retrospective Evaluation
   Sang Soo Eun, MD, Sang-Ho Lee, MD, PhD, and Luigi Andrew Sabal, MD.

BACKGROUND: Open lumbar microdiscectomy (OLM) has been considered the gold standard in the management of lumbar disc herniation (LDH) for its favorable outcomes in long-term follow-up. Nowadays, percutaneous endoscopic lumbar discectomy (PELD) is gaining recognition. However, greatest limitation of studies of PELD is the lack of long-term follow-up outcomes.

OBJECTIVE: To investigate the long-term outcomes of PELD in terms of clinical and radiographic findings and revision surgery rate.

STUDY DESIGN: Retrospective study.

SETTING: Spine hospital.

METHODS: Sixty-two patients who underwent PELD 10 years previously were contacted for follow-up. Clinical parameters such as the visual analog scale scores for the back and legs (VAS-B and VAS-L, respectively), the Oswestry disability index (ODI), and radiographic findings such as the disc-height ratio and change in the difference between flexion and extension were recorded and compared to the preoperative values.

RESULTS: For 62 followed patients, 38 met our inclusion criteria (35 transforaminal, 3 interlaminar). Excluded were 6 patients (9.4%) who underwent revision OLM at same level and 17 patients (26.6%) who underwent lumbar spine surgery at other levels. The average follow-up period was 11.22 (± 0.83) years. For the remaining 38 patients who had no further surgery, the postoperative VAS-B (2.53 ± 1.98), VAS-L (1.82 ± 1.92), and ODI (12.69 ± 11.26) were significantly different from the pre-operative values (8.45 ± 1.52, 7.40 ± 3.04, and 55.33 ± 24.63, respectively; all P = 0.01). The average disc-height ratio was 81.54% of the original disc height. There was no evidence of instability after long-term postoperative follow-up.

LIMITATION: Retrospective nature of data collection.

CONCLUSION: PELD has favorable long-term outcomes.

Key words: Long-term, PELD, endoscopic lumbar discectomy, revision rate, disc height, instability