Full endoscopic contralateral transforaminal discectomy for distally migrated lumbar disc herniation

Discectomy of distally, inferiorly migrated disc herniations below midpedicle level of the vertebral body in the lower lumbar spine is known to be very difficult by endoscopy. The purpose of this study was to introduce the technical possibility of percutaneous endoscopic lumbar discectomy using a contralateral transforaminal approach for distally migrated disc herniation. We reviewed 12 patients who underwent percutaneous endoscopic lumbar discectomy using the contralateral transforaminal approach for distally migrated disc herniation. Complete removal was verified through postoperative magnetic resonance imaging (MRI) follow-up in all patients. Mean follow-up was 25 months. Clinical results according to MacNab criteria were excellent in ten patients and good in two. Average visual analogue scale for lower back pain and radicular pain improved from 6.8 and 8.2 preoperatively to 1.5 and 1.4, postoperatively (p < 0.01, respectively). Percutaneous endoscopic lumbar discectomy using contralateral transforaminal approach can be a useful method in patients with distally migrated disc herniation, and endoscopic navigation of anterior epidural space from the contralateral foramen in the lower lumbar spine is technically possible.