Transforaminal Endoscopic Lumbar Discectomy With Bone Drill-Assisted Foraminoplasty in Recurrent Disc Herniation

0:00 Title

We will discuss our experience with transforaminal endoscopic lumbar discectomy (TELD) using bone drill-assisted foraminoplasty in recurrent disc herniation.

0:20 Recurrent disc herniation

Recurrent disc herniation presents a significant challenge, but TELD is both effective and feasible, reducing surgery-related complications and operative time. After discectomy, issues such as disc height reduction, facet arthropathy, and foraminal narrowing can make endoscopic access difficult and increase the risk of exiting nerve injury.

0:42 Endoscopic foraminoplasty

Foraminoplasty is a technique to widen the foramen, allowing better access to the cannula near the herniated disc and removing the superior articular process (SAP). Endoscopic foraminoplasty was first introduced by Knight et al. [1] in 2001 using a Holmium:YAG side-firing laser undercutting of facet joint, discectomy, mobilization of exiting and traversing nerve roots, and ablation of osteophytes.

1:13 Summary of literature

Here's a summary of key studies on foraminoplasty:

In foraminal stenosis, Knight et al. [1] reported a 73% success rate using a laser, with a 5% revision rate. Ahn et al. [2] achieved an 82% success rate using endoscopic drill, laser, and micropunch, with a 3% revision rate. In disc herniation, Schubert and Hoogland [3] reported a 95% success rate using a reamer, with a 3.6% revision rate. Choi and Park [4] also reported high success rates using endoscopic drills and reamers, with low revision rates.

1:52 Target of Foraminoplasty

The targets of foraminoplasty vary depending on the type of disc herniation [5]. L5–S1 disc herniation involves the cranial tip of SAP. Central disc herniation and recurrent disc herniation involve the mid-part of SAP. Down-migrated disc herniation involves the base of SAP and partial upper pedicle.

2:13 Indication

Endoscopic lumbar foraminoplasty is indicated for: high-grade down migration, downward sequestration, decreased disc height, recurrent disc herniation, central disc herniation with a wide lamina angle, L5-S1 disc herniation with a high iliac crest [6]. For these conditions, foraminoplasty may be required to facilitate TELD.

2:38 Equipment

We use the transforaminal system for these procedures. The bone drill is an essential tool in our foraminoplasty procedures. Patients are positioned prone and the procedure is performed under local anesthesia.

2:51 Case 1 Presentation

Case 1 involves a 79-year-old male with right leg radiating pain and a history of microscopic discectomy at L4–5 6 months ago. Physical examinations reveal right great-toe dorsiflexion weakness. Preoperative magnetic resonance imaging (MRI) showed downward migrated disc herniation with previous laminectomy. X-ray showed foraminal stenosis.

3:15 Surgical Procedure - Foraminoplasty

Foraminoplasty was performed using a bone drill. First, perform a discography. Then, place the needle in the craniocaudal direction at the base part of the SAP. Insert the smallest bone drill and ream the area. Gradually increase the diameter of the drill for reaming. After removing the final bone drill, insert the working cannula.

3:40 Surgical Procedure - Discectomy

When the endoscope is inserted, the right side will be cranial, the left side will be caudal, the lower part will be the disc space, and the upper part will be the epidural space. The ruptured disc fragment will be immediately visible, and the disc fragment is removed.

Once several pieces of the disc are removed, the nerve root and dural sac will be visible, and pulsation will be noticeable. This indicates that sufficient decompression has been achieved.

4:25 Postoperative Course

Postoperative MRI shows successful decompression with no complications. Yellow arrows indicate foraminoplasty sites.

4:33 Case 2 Presentation

Case 2 involves a 69-year-old female with left leg radiating pain and a history of microscopic discectomy at L4–5 twelve years ago. Physical examinations reveal left great-toe dorsiflexion weakness and decrease of sensory as L5 dermatome. Preoperative MRI showed tiny recurrent disc herniation compressing L5 nerve root.

5:00 Surgical Procedure - Foraminoplasty

First, perform a discography. Then, place the needle in the craniocaudal direction at the base part of SAP. Insert the smallest bone drill and ream the area. Gradually increase the diameter of the drill for reaming. After removing the final bone drill, insert the working cannula.

5:21 Surgical Procedure - Discectomy

In the endoscope view, the left side is cranial, the right side is caudal, the lower part is the disc space, and the upper part is the epidural space. Remove the ruptured disc fragments from the disc space and feel the pulsation in the epidural space. Use a probe to confirm decompression around the nerve root.

6:06 Surgical Photo

The photo shows multiple disc fragments. Blood-tinged disc means ruptured disc fragment.

6:12 Postoperative Course

Postoperative MRI shows successful decompression with no complications. Both patients had no intraoperative complications and were discharged on postoperative day 1 with immediate pain relief. Incisions were closed with glue.

6:27 Surgical Tips

Some surgical tips include – a more caudal approach along the superior border of the inferior pedicle may be safer. Serial dilation and sequential reaming can reduce injury to the exiting nerve root [7]. Avoid reaming with too steep an angle to prevent violation of the disc space. The bone drill should not go beyond the medial pedicular line.

6:49 Conclusion

In conclusion, TELD with foraminoplasty using a bone drill is an effective and feasible technique for addressing recurrent disc herniation with even foraminal stenosis. This method takes a short time and improves surgical outcomes.

7:05 References

References for this presentation include works by Knight, Choi, Schubert, Ahn, and others.