Abstract

Introduction: Migrated disc herniations (MDH) pose a greater challenge even for experienced endoscopic surgeons. The transforaminal window provides limited access, which although proves adequate for removal of low-MDH, may render PELD ineffective in cases of H-MDH. These herniations are hidden from the endoscopic view by anatomic barriers like hypertrophied facet, inferior pedicle and foraminal ligaments. There is difficulty encountered in obtaining an optimal working trajectory; it being significantly hindered by these barriers. Enlargement of foramen by undercutting of ventral (nonarticular) part of superior-facet, upper border of inferior pedicle along with ablation of foraminal ligament, called as foraminoplasty, can help us to address this issue. Methods: 59 patients with soft H-MDH who underwent PELD with foraminoplasty under local anesthesia between Jan 2002 to June 2006 were analyzed retrospectively. Using clinical charts and mailed questionnaires, we evaluated the patients by postoperative VAS for leg pain and ODI scores. Outcomes were graded according to modified Mac-Nab criteria. Results: Mean follow-up was 25.4 months. Mean VAS score for radicular pain improved from 8.01 to 1.56, and mean ODI improved from 61.6 to 10.76. Based on Mac-Nab criteria, 89.8% of patients experienced satisfactory outcome. Two patients had persistent leg pain postoperatively. One patient who underwent a repeat-PELD procedure after one month was relieved of symptoms. Another patient was subjected to open discectomy after 25 weeks from the first operation and showed improvement. Two patients had recurrent herniation at same level after 6 months; one patient underwent repeat PELD and the other, open discectomy. Both had good results. None of the patients suffered from dysesthesia postoperatively. There were no cases of infection, instability or further recurrence at the time of final follow-up. Conclusions: Foraminoplastic-PELD is safe and effective procedure for surgical treatment of soft H-MDH. The results are comparable to results of open surgery.