New surgical techniques of percutaneous endoscopic lumbar discectomy for migrated disc herniation

Abstract

Objectives: Although percutaneous endoscopic lumbar discectomy (PELD) offers a favorable outcome for protruded discs, there have been difficulties for migrated discs. The purpose of this study was to present new surgical techniques of PELD for migrated disc herniation.
Patients and methods: From April 2002 to March 2003, 116 patients (73 males, 43 females; mean age 35.5 years; range 16 to 68 years) underwent PELD for radiculopathy due to migrated discs. According to preoperative MRI findings, disc migration was classified into four zones based on the direction and distance from the disc space. Two surgical techniques were used according to this classification. Far-migrated discs (zone 1 and 4) were treated with the "epiduroscopic" technique, which involved introducing the endoscope into the epidural space directly. Near-migrated discs (zone 2 and 3) were treated with the "half-and-half" technique, which involved positioning a beveled working sheath across the disc space to the epidural space. The clinical outcome was evaluated according to the modified Macnab criteria,. The intensity of pain was measured by a visual analogue scale (VAS). The mean follow-up period was 14.5 months (range 9 to 20 months).
Results: According to the modified Macnab criteria, satisfactory (excellent or good) results were distributed as follows: 91.6% (98/107) in the down-migrated discs, 88.9% (8/9) in the up-migrated discs; 97.4% (76/78) in the near-migrated discs, and 78.9% (30/38) in the far-migrated discs. The mean VAS score significantly decreased from 7.5 preoperatively to 2.6 at the final follow-up (p<0.0001). The mean time to return to work was 12.5 days. There were no approach-related complications.
Conclusion: Using the classification proposed, the two techniques of PELD can be safely employed in the treatment of migrated disc herniation.