Surgical Outcome of Percutaneous Endoscopic Interlaminar Lumbar Discectomy for Highly Migrated Disk Herniation

Study Design: Technical report. Objective: To present a detailed surgical technique for percutaneous endoscopic interlaminar discectomy (PEID) for highly migrated disk herniation. Summary of Background Data: Percutaneous lumbar endoscopic discectomy for highly migrated disk herniation is still challenging even for an experienced surgeon. Because of the risk of failure and technical difficulty, open discectomy is recommended for a high-grade migration. However, past reports focused on the transforaminal approach (percutaneous endoscopic transforaminal discectomy) and may give a biased impression. We may overlook the merit of PEID. The surgical procedure for PEID is similar to a traditional open discectomy and the range of approach could be widened by the inclined introduction and pivoting motion of an endoscope. Methods: Eighteen consecutive patients (M:F = 12:6; age, 56 +/- 15 y) with highly migrated disk herniation were enrolled for the present study. The disk material was migrated superiorly in 7 patients (L4-5, 4; L5-S1, 2; L2-3, 1) and inferiorly in 11 patients (L4-5, 6; L3-4, 4; L5-S1, 1). PEID was applied in 17 patients and PETD was performed for L2-3 disk herniation. The follow-up period was 16 +/- 12 months. The outcome was graded using the MacNab criteria. Results: Complete removal of the disk material was confirmed with magnetic resonance imaging in 16 patients (success rate 89%). Revision operation was necessary in 2 patients with inferior migration from L4-5. The residual disk was removed through the L5-S1 laminar window 2 days after surgery with excellent outcome at the last follow-up. The outcome at the last follow-up was excellent in 12 patients, good in 3, fair in 2, and poor in 1. Dural tear was suspected in 1 patient without any further problems and there was no recurrence during follow-up. Conclusions: PEID may be applied comfortably even for less-experienced surgeons because of the familiar anatomy with open surgery.