PMC8769379_01
Preoperative T2-weighted magnetic resonance images showing (a) a well-defined cystic lesion (arrow) with homogeneous high signal intensity at L4/5 in left paramedian sagittal view and (b) the cystic lesion (large arrow) and lumbar disc herniation (small arrows) on the left side through the L5 endplate. The lateral recess appears to be stenotic.
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F1
MRI revealed an intraspinal extradural space-occupying cystic lesion on the left side at L4/5 that was hypointense to isointense on T1-weighted images and hyperintense on T2-weighted images (Fig. 1).
Computed tomography scans after discography shows filling of the cyst by contrast medium in-flow (arrow). The cyst is located in the left ventrolateral extradural space.
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F2
Discography and computed tomography (CT) discography confirmed flow of contrast into the cyst via connecting channels (Fig. 2).
Intraoperative transforaminal full-endoscopy findings. (a) Using a surgical bur, the superior articular process was drilled and the foramen was enlarged (foraminoplasty). (b) The cyst was exposed using a bipolar device (arrows). (c) Puncture with a bipolar device resulted in (d) discharge of serosanguinous fluid from the cyst. (e) Disc herniation (blue stain) was also completely removed. SAP: superior articular process.
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F3
First, we performed foraminoplasty to avoid irritation of the L4 exiting nerve root (Fig. 3a). We located the cyst, which had a distinct capsule consisting of whitish soft thick fibrous tissue in the left ventral aspect of the dura (Fig. 3b). The cyst ruptured easily on bipolar electrocautery (Fig. 3c), releasing a serosanguinous fluid (Fig. 4d). The disc herniation was completely removed using the outside-in technique (Fig. 3e).
Postoperative T2-weighted sagittal and axial magnetic resonance images confirm decompression and complete excision of the cyst.
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F4
MRI after surgery confirmed that the discal cyst and herniated mass had been successfully removed endoscopically (Fig. 4).