# Transforaminal Endoscopic Lumbar Discectomy for Migrated Disc Prolapse: A Retrospective Study of 169 Patients

## TL;DR

This study shows that transforaminal endoscopic lumbar discectomy is effective for treating migrated disc prolapse, even in severe cases.

## Contribution

The study demonstrates that TELD is a viable treatment for migrated disc prolapse, challenging previous contraindications.

## Key findings

- TELD achieved significant functional improvements in 169 patients with migrated disc prolapse.
- Postoperative MRI confirmed optimal decompression in all cases with no need for reoperations.
- Minor complications occurred in 10.65% of cases but had no long-term consequences.

## Abstract

Background

The effectiveness of transforaminal endoscopic lumbar discectomy (TELD) has been questioned, but it is evolving. Although it provides acceptable, comparable, or even better results in sporadic reporting, TELD was contraindicated by many for migrated disc prolapse (MDP) and central disc prolapse (DP). This study aimed to evaluate the effectiveness of transforaminal endoscopic discectomy in MDP.

Methodology

The study was conducted at Stavya Spine Hospital and Research Institute between October 2010 and December 2023. All patients provided informed consent and underwent the procedure under local anesthesia. The inclusion criteria were lumbar degenerative DP with unilateral or bilateral symptoms at the L1-L5/S1 disc levels. Foraminal, extraforaminal, pure soft disc bulge, protrusion, extrusion, and calcified disc without craniocaudal migration were excluded. Intracanalicular-only extrusion and sequestration were included. Inside-out (IO) TELD was performed for all possible cases of low-migrated and high-migrated LDH. In cases of highly migrated LDH, the outside-out (OO) technique or transpedicular (TP) technique was also employed. If required, endoscopically visualized burr-foraminoplasty (FP) was added to the IO or OO primary techniques. The supra-facetal (SF) technique was employed when the highly migrated fragment was large, singular, and afresh (less than three weeks’ history). Carl Storz’s endoscopic system, Richard Wolf’s, Maxmore’s, or Joimax’s systems were used, along with self-designed instruments. Adequacy of decompression was confirmed by probing, fluttering dura, pulsatile dura, dural root fall-back, and MRI confirmation. Functional outcomes were assessed using the Numerical Rating Scale (NRS), Patient Satisfaction Index, return to basic work/job, and Oswestry Disability Index (ODI) scores.

Results

There were 169 patients with a minimum follow-up period of 24 months. Statistically significant (p < 0.05) ODI and NRS improvements were noted in all patients immediately and at six weeks without perioperative complications. All patients underwent daycare surgery and were able to resume their basic job activities within three weeks. Low, high, and very-high-migrated DP were 76, 62, and 31, respectively. OO was performed in 29 patients. Three patients underwent the TP approach, and 20 underwent the SF approach without foraminoplasty. The remaining patients underwent the IO technique (n = 117). Endoscopic FP was required in 27 cases of L5-S1 and at nine other spinal levels. Postoperative MRI showed adequate optimal decompression in all cases. The overall number of minor complications that had no long-term consequences was 18 (10.65%). Nine patients had residual fragments without any symptoms. Two patients with OO had a postoperative dysesthesia (POD) of the exiting nerve root. Five patients had protracted recovery of leg symptoms (POD traversing root) that took three weeks to resolve despite optimal decompression. No reoperations were required for MDP.

Conclusions

TELD decompression is an effective alternative for managing MDP. Excellent outcomes are possible even in highly migrated MDP, and TELD is no longer a contraindication.