Suprapedicular Retrocorporeal Technique of Transforaminal Full-Endoscopic Lumbar Discectomy for Highly Downward-Migrated Disc Herniation

OBJECTIVE: Anatomical barriers (e.g., pedicles, narrow foramina) can hinder direct access to, and removal of, disc fragments that have migrated far downward. Using transforaminal full-endoscopic lumbar discectomy (FELD), we devised a modified technique, the suprapedicular retrocorporeal approach, for herniations in which the disc has migrated to the axilla of the traversing nerve roots. In the present report, we have described our preliminary results. METHODS: Soft, highly downward-migrated disc herniation was treated with transforaminal FELD through the suprapedicular retrocorporeal approach in 22 patients from June 2017 to May 2019. The clinical outcomes were evaluated, including the preoperative and postoperative visual analog scale scores for the back and leg, Oswestry disability index, and MacNab criteria for surgical success. RESULTS: The affected discs were at L4-L5 in 14 patients, L3-L4 in 6 patients, and L5-S1 in 2 patients. In each case, the affected disc was successfully removed using the suprapedicular retrocorporeal approach. The mean follow-up was 18.1 +/- 5.7 months. The mean visual analog scale scores for back and leg pain improved significantly (P < 0.05 for both). The mean Oswestry disability index had decreased from 62.5 +/- 14.2 preoperatively to 10.5 +/- 5.9 postoperatively (P < 0.05). Using the MacNab criteria, 13 patients reported excellent outcomes and 9, good outcomes. No complications or recurrence developed during follow-up. CONCLUSIONS: The suprapedicular retrocorporeal technique is a feasible and effective surgical option in transforaminal FELD for the treatment of herniation in which the disc has migrated to the axilla of the traversing nerve roots.