Intradural disc herniation: how I do it

Intradural lumbar disc herniation: A case report and literature review

Study design and objection

Intradural disc herniation is a unusual disease associated with spinal surgery. The definitive diagnosis of intradural herniation depends on intraoperative findings.

Summary of background data

We present the case of a 63-year-old woman with backache and left sciatica radiation for more than two months. The L2/3 laminectomy and discectomy were performed after magnetic resonance imaging (MRI) study; however, no disc rupture was noted during surgery. Follow-up lumbar spine MRI revealed one large, ruptured disc. The patient underwent revision surgery with durotomy. The large intradural disc was found and removed piece by piece.

Methods Results and Conclusions

Intradural disc herniation, especially large herniation, is hard to diagnose specifically despite the progression of neuroradiologic imaging techniques. A durotomy procedure should be considered if there is a missing ruptured disc or a palpable intradural mass during surgery.

Upper Lumbar Intradural Disc Herniation: A Rare Case Report and Etiologic Analysis

Background

Intradural disc herniation (IDH) is a rare type of disc degeneration that infrequently affects the upper lumbar spine. Pre- and intraoperative diagnosis and surgical management of IDH are challenging. The present case study provides insight into these aspects of upper lumbar IDH and discusses possible mechanisms.

Case Description

A 63-year-old female with a history of chronic lower back and leg pain presented with an acute lumbar sprain that had occurred 1 month prior. The pain progressed and spread to the front of the left thigh, which affected her ability to lift her leg when ascending/descending stairs. Sagittal gadolinium-enhanced magnetic resonance imaging (MRI) revealed a disc protruding into the ventral dural sac showing a hawk-beak sign, and the posterior edge of the disc annulus and local posterior longitudinal ligament was broken. Total L2 laminectomy was performed, and the dorsal side of the dural sac was exposed and incised to enable exploration of the ventral side of the dura. We found two free fragments protruding into the inner wall of the dura through the left ventral dura mater defect. After carefully and completely removing the mass, we repaired the defect and performed internal fixation. Postoperative pathologic analysis confirmed that the mass was nucleus pulposus tissue from the degenerated disc. The patient’s pain significantly improved after surgery, and she was able to walk normally at the 1-month follow-up.

Conclusion

Upper lumbar IDH is an extremely rare type of disc degeneration. An enhanced MRI scan can provide diagnostic evidence, but the final diagnosis requires surgical exploration of the path of herniation and pathologic examination of the mass lesion.

L1/2 Intradural Disc Herniation with Compression of the Proximal Cauda Equina Nerves: A Surgical Challenge

BACKGROUND

Intradural disc herniation (IDH) in the upper lumbar spine is rare. Preoperative radiologic diagnosis can be difficult, making operative planning challenging. We report on a 74-year-old female patient who was diagnosed with an L1-L2 IDH intraoperatively. This case report aims to highlight and discuss the radiological features of IDH and operative challenges when approaching IDH.

CASE DESCRIPTION

A 74-year-old female patient presented to outpatient clinic with a 3-month history of significant intermittent neurological claudication and severe lumbar back pain. Her examination was unremarkable apart from a positive left-sided femoral stretch test. Magnetic resonance imaging (MRI) revealed a large central L1/L2 disc herniation causing significant compression of the thecal sac and proximal cauda equina nerve roots. She underwent an elective posterior L1/L2 lumbar exploration. Intraoperatively, identification of the disc was difficult, which led to inadvertent cerebrospinal fluid leak after incision of what was thought to be a disc bulge. Further exploration revealed an intradural disc that was removed via durotomy. The thecal sac was repaired with sutures and TISSEEL (Baxter, Deerfield, Illinois, USA). Postoperatively, the patient complained of weak left lower limb; MRI revealed residual disc remnants causing compression of the cauda equina. She successfully underwent an urgent revision decompression procedure. She was discharged to rehabilitation on postoperative day 14 with weakness in left knee flexion and extension (MRC grade 4/5) and left ankle plantar- and dorsiflexion (MRC grade 2/5).

CONCLUSIONS

Upper lumbar IDH represent a surgical challenge. Intraoperative considerations include identification of the disc, intentional or incidental durotomy, intradural discectomy, and anatomical restrictions of operating at the level proximal to the cauda equina.

Intradural disc herniation at the L1-L2 level: A case report and literature review

Background:

Why are intradural disc herniations (IDHs) (0.3% of all discs) so infrequent? One explanation has been the marked adherence of the posterior longitudinal ligament (PLL) to the ventral wall of the dura. Variability in symptoms and difficulty in interpreting magnetic resonance (MR) images with/without contrast make the diagnosis of an IDH difficult. Here, we reported a patient with an L1–L2 IDH and appropriately reviewed the relevant literature.

Case Description:

A 57-year-old male presented with chronic low back and 1 month’s duration of the left thigh pain. The lumbar MR with/without contrast demonstrated an IDH at the L1–L2 level, resulting in spinal cord compression. At surgery, the disc herniation was appropriately resected, the dura was closed, and an interbody fusion with pedicle screw fixation was performed. Postoperatively, the patient clinically improved.

Conclusion:

IDHs are rare, being seen in only 0.3% of all cases. MR findings, performed with/without contrast, may help signal the presence of an IDH. MR findings include a hypointense structure inside the dura; the “hawk beak” sign (e.g., beak-like mass with ring enhancement at the intervertebral disc space); the Y sign (e.g., ventral dura split into ventral dura and arachnoid by disc material); an abrupt loss of continuity of the PLL; a diffuse annular bulge with a large posterocentral extrusion; and an typical crumbled appearance of disc (e.g., “crumble disc sign”). At surgery, both the extradural and intradural components of the disc must be excised.