Los Angeles Minimally Invasive Spine Institute director, Dr. George Rappard, reported on the results of a long-term study group of 108 patients who underwent endoscopic lumbar discectomy for the treatment of a herniated disc. Long-term success was achieved in 90% of cases. In successfully treated cases back pain was reduced by 61%, sciatica, or leg pain, was reduced by 60% and disability was reduced by 50%. Rappard notes that these results are consistent with the long-term results of more invasive spine surgery.  Here is the source and additional details.