|Year : 2017 | Volume
| Issue : 1 | Page : 68-72
Percutaneous endoscopic interlaminar lumbar discectomy for superiorly sequestrated disc L5–S1: A case report with technical review
Manish Raj1, Hyeun Sung Kim2, Kailash Kothari3, Anurag Agarwal4, Kifayat Maqsood5
1 Department of Interventional Spine and Pain, Jaypee Hospital and Yatharth Hospital, Noida, Uttar Pradesh, India
2 Department of Neurosurgery, Nanoori Suwon Hospital, Seoul, South Korea
3 Department of Interventional Spine and Pain, Pain Clinic of India, Mumbai, Maharashtra, India
4 Department of Interventional Spine and Pain, Ram Manohar Lohia Government Hospital, Lucknow, Uttar Pradesh, India
5 Department of Internal Medicine, Yatharth Hospital, Noida, Uttar Pradesh, India
|Date of Web Publication||5-May-2017|
Department of Interventional Spine And Pain, Yatharth Superspecialisty Hospital, Noida, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
L5-S1 disc has always been a difficult disc to target by rigid endoscope because of anatominal limitations .These limitation severely hampers transforaminal approach for superiorly migrated disc at L5-S1. We performed percutaneous endoscopic interlaminar lumbar decompression (PEILD) for removal of superiorly migrated sequestrated disc and preserved the functional structures. Through this approach nerve root and dural sleeve were exposed and adequate removal of migrated disc was done, which was also confirmed by immediate post operative MRI. The clinical outcome was evaluated using visual analogue scale (VAS) score and brief pain inventory (BPI) . We obtained excellent results in treating superiorly sequestrated disc at L5-S1 using endoscopic interlaminar angled approach.
Keywords: Endoscopic, interlaminar, superior migrated, sequestrated, herniated disc
|How to cite this article:|
Raj M, Kim HS, Kothari K, Agarwal A, Maqsood K. Percutaneous endoscopic interlaminar lumbar discectomy for superiorly sequestrated disc L5–S1: A case report with technical review. Indian J Pain 2017;31:68-72
|How to cite this URL:|
Raj M, Kim HS, Kothari K, Agarwal A, Maqsood K. Percutaneous endoscopic interlaminar lumbar discectomy for superiorly sequestrated disc L5–S1: A case report with technical review. Indian J Pain [serial online] 2017 [cited 2019 Oct 20];31:68-72. Available from: http://www.indianjpain.org/text.asp?2017/31/1/68/205716
| Introduction|| |
Microlumbar discectomy has been the gold standard in the treatment of discogenic low back radiating pain; however due to the development of relevant equipment such as high-resolution rigid rod lens, endoscopic forceps, drill, burr, radiofrequency probe, and laser, it has now become possible to treat most lumbar disc herniation with percutaneous endoscopic disc decompression.
In cases of L5–S1 disc herniation with superior migration, percutaneous transforaminal endoscopic disc decompression has technical difficulties due to high iliac crest, large facetal mass, and high oblique orientation of L5–S1 disc. Although few authors have published work on trans-iliac endoscopic approach for superiorly migrated disc herniation, in our view, there is a safe and less destructive interlaminar approach with technical modification to address the up-migrated disc herniation. Our case was further complicated by not only up-migration but also due to sequestration above L5–S1 level. We performed inter-laminar angled approach to reach the sequestration site and adequate decompression was done.
| Case Report|| |
A 44-year-old male presented with the complaints of severe low backache radiating to the right leg for 5 days with numbness and weakness in the right leg. The lesion of patient was sequestrated disc lying posterior of L5 vertebrae causing lumbar canal stenosis. The origin for sequestration seems to be L5–S1 disc, which was confirmed radiologically [Figure 1], [Figure 2], [Figure 3]. The patient underwent percutaneous endoscopic interlaminar lumbar decompression (PEILD) through a ipsilateral interlaminar approach. Outcomes were evaluated using visual analog scale (VAS) score and Brief Pain Inventory (BPI) scale, and adequate decompression was checked by preoperative and immediate postoperative magnetic resonance imaging (MRI).
|Figure 1: T2 Sagittal image (sequestrated disc posterior to L5 vertebrae)|
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|Figure 3: T2 axial vertebral cut( canal stenosis caused by ruptured disc in axial view)|
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Prior to the surgery, anatomical structures in the pathway of instruments were evaluated on preoperative MRI. Interlaminar distance from the lower border of L5 lamina to superior border of S1 lamina was measured and it was found to be 20 mm. With 20 mm interlaminar distance, we can easily insert 8 mm working sleeve, but we had to confirm the angle of trajectory superiorly since the disc was lying posterior to the middle of L5 vertebrae.
The patient received preoperative intravenous (IV) antibiotic injection cefazolin 2 g IV 60 min before the procedure. After explaining the patient about the procedure in detail and obtaining written informed consent, he was placed in the prone position on a radiolucent table. The operative area was cleaned and draped. Discography was performed through transforaminal approach. A volume of 3 ml of methylene blue mixed with radio-opaque contrast (omnipaque) in 3:3 ml concentration was injected to stain the degenerated disc and differentiate between normal and prolapsed disc. In addition, it helps us in identifying the connection between the sequestrated segment and the L5–S1 disc. The whole procedure was performed with conscious sedation using midazolam and fentanyl. The patient received interlaminar epidural anesthesia at L2–L3, 15 ml of analgesic dose of ropivacaine 0.25% followed by continuous infusion at 5–10 ml/h with catheter in situ, and the procedure was proceeded with continuous feedback from the patient as he was fully conscious.
Fluoroscopic guidance was used to identify the L5–S1 disc space. A vertical midline was drawn on the skin, followed by horizontal line across the center of the targeted disc under c-arm. The skin was marked at the lateral most part of flavum (corresponding to the medial border of superior articular process of S1 in posteroanterior c-arm view) forming an angle with medial pedicular line and superolateral edge of the first sacral lamina (also known as V point). Skin incision was made with No. 11 knife parallel to midline for 6–7 mm. A single obturator was inserted till ligamentum flavum with maintenance of trajectory 25° in coronal plane toward posterior mid portion of L5 vertebral body [Figure 4] and confirmed in anteroposterior/lateral view of c-arm. A working channel was inserted over the obturator. The obturator was removed and then the endoscope was inserted. The ligamentum flavum was splitted with a probe, and the working channel moved toward the most upper and lateral part of ligamentum flavum [Figure 5].
|Figure 4: Angled sleeve from outside (superior angulation of sleeve to reach posterior to L5 vertebrae)|
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|Figure 5: Angled sleeve C-arm view ( tip of working sleeve at ruptured disc location)|
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Once entered into the spinal canal, neural structure and dural sleeve were identified [Figure 6] and the epidural fat was dissected with a radiofrequency electrode and forceps. Bevel of the working channel was penetrated through the splitted point of the ligamentum flavum and was rotated protecting the nerve root and surrounding structures. A partially stained sequestrated disc compressing an exiting nerve root and dural sleeve was identified. The ruptured disc was removed with an endoscopic forceps [Figure 7]. After decompression of the lesion and hemostasis, the scope was removed [Figure 8]. Decompression of the lesion was confirmed with immediate postoperative MRI [Figure 9].
|Figure 6: Endoscopic view of neural tissue [S1 nerve root (inferior) has been compressed medially to dural sleeve(superior) by ruptured disc]|
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|Figure 9: Pre- post operative MRI comparison (adequate decompression can be seen, when compared to pre op MRI)|
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| Results|| |
The average VAS score was reduced from 9 preoperatively to 2 immediately postoperatively. Postoperative dorsiflexion of foot improved from 1 to 3 immediately and up to 4 within 7 days. Ankle jerk reflex improved from 1 + to 2+. The pain severity score on BPI reduced from 9 to 2 postoperatively. Postoperative MRI showed that the ruptured disc had been successfully removed. There were no complications such as dysesthesia, hematoma, or infection. The patient did not require any additional procedure.
| Discussion|| |
Since Kambin and Sampson first introduced lumbar disc decompression through a posterolateral approach, there have been remarkable advances in percutaneous endoscopic lumbar disc procedures. With the development of various instruments related to spinal endoscopic procedures, now nearly all symptomatic lumbar disc herniation can be treated through endoscope.
As L5–S1 level has considerable anatomical features, such as high iliac crest, facet joint hypertrophy, relatively narrow foramen, and wide interlaminar space, several approaches to ruptured disc at the L5–S1 level have been considered, such as transforaminal, ipsilateral interlaminar, and trans-iliac.,, Choi et al. compared the transforaminal approach to the interlaminar approach in detail, depending on the location of lesion, but limited the lesion to intracanal disc herniation and did not include foraminal disc lesions or sequestrated lesion. In 2016, Lee et al. in a technical case report have shown the effectiveness of contralateral interlaminar endoscopic discectomy for foraminal disc herniation at L5–S1. Lee et al. showed that a satisfactory outcome was obtained in 78.9% (30/38) of the patients with highly migrated disc herniation with the percutaneous endoscopic transforaminal lumbar discectomy technique, but it was limited to inferior migrated disc.
Using an excessive cranial-to-caudal skin entry point due to the high iliac crest increases the possibility of encountering an existing nerve root injury. It is also difficult to approach L5–S1 disc herniation with superior migration through the ipsilateral transforaminal approach due to high iliac crest. Discography was performed through transforaminal approach as it is not advisable to do discography by interlaminar approach since the exact location of dural sleeve and exiting S1 root is not known, though few authors promote interlaminar discography for shoulder-type L5–S1 herniation. We suggest the use of transforaminal approach for evocative discography with 3 ml of methylene blue mixed with radio-opaque contrast (omnipaque) in 3:3 ml concentration. Methylene blue being base stains the acidic degenerated nuclear tissue. We did discography to see whether there is any tract of sequestrated material with L5–S1 disc, since MRI was not conclusive of the same.
Cases have been reported for protruded and extruded superior migrated disc at L5–S1 through ipsilateral interlaminar approach, but addressing L5–S1 superiorly sequestrated disc with rigid endoscope has not been reported yet. The reason is due to steep cranio-caudal angle of sequestrated disc from skin entry point and overhanging lamina of L5 leading to difficulty in reaching such disc. Thus, microscopic lumbar discectomy through a paramedian transmuscular approach has been used for this type of lesion. Lee et al. recommended that open surgery should be considered for far-migrated disc herniation. However, the open discectomy, such as paramedian Wiltse approach and hemilaminotomy, needs extensive resection of the lamina, especially in the region of the pars interarticularis. This may result in iatrogenic instability and increasing postoperative morbidity. Microlumbar discectomy also requires partial facetectomy; if more than 40%–50% of facet is removed, instability may arise, inducing postoperative pain., The discs, facet joints, supraspinous ligaments, and paraspinal muscles of the lumbar spine are important structures that maintain a stability of segmental motion. Instability increases when surrounding structures are damaged., PEILD through ipsilateral interlaminar approach can maximally preserve these structures.
If the interlaminar space is relatively narrow, it might render an approach to superior migration difficult, as the laminar space would block the trajectory. In such a case, a trajectory approach can be acquired by undercutting the inferior margin of the lesion-side facet using an endoscopic drill. Fortunately, in the present case, we were able to approach the sequestration site without using an endoscopic drill. The outcomes were satisfying, however further study will be needed with more number of cases to establish the effectiveness of PEILD for superiorly sequestrated disc.
Since insertion of the working channel at a sharp angle may cause injury to the thecal sac, it is important to dock the working channel to the medial border of the inferior facet of lesions safely at an approximately 45° angle. In addition, splitting a ligamentum flavum without clarifying the boundaries of the bone and ligamentum flavum may cause exiting nerve root injury, thereby requiring attention.
The advantages of the standard open surgery over endoscopic discectomy for highly migrated disc or sequestrated disc herniation are the direct approach to the distal end of the migrated fragment and less risk of disc residue. However, compared with the conventional open surgery, PEILD offers several advantages such as normal paraspinal structure preservation, minimal postoperative pain, lower risk of postoperative epidural scar formation, and iatrogenic instability. Hence, if trajectory permits, ipsilateral PEILD is a safe option for superior migrated sequestrated disc herniation at L5–S1.
| Conclusion|| |
This study achieved good result through an interlaminar cranially angled endoscopic approach for L5–S1 sequestrated disc herniation with superior migration. This can be a considerable option for the treatment of ruptured discs that had previously been difficult to approach with a rigid endoscope.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]