I know that dural leak that occurs during a spine procedure is inclusive to the procedure; however, the defect was already present…likely due to corticosteroids. I know that you could possibly report modifier 22 for the dural repair if the repair required additional bone removal for exposure. What’s your opinion on this? (I’m not questioning the other procedures)


1. Large left L3-4 extradural cystic lesion with evidence of multiple previous hemorrhagic events, probable synovial cyst.

2. Smaller left L2-3 synovial cyst.

3. Midline dural defect at L2-3 surrounded by evidence of epidural corticosteroids, likely related to prior L2-3 epidural steroid



1. Left L3 hemilaminectomy with extensive L2-3 and L3-4 foraminotomies, decompression and partial removal of the capsule of the epidural lesion, decompression of neural elements.

2. Left L2-3 foraminotomy with removal of synovial cyst and decompression of L3 nerve root.

3. Central L2-3 laminotomies with primary repair of dural defect utilizing suture, supplemented with fibrillar and DuraSeal.

Once the self-retaining retractors were in place I did remove a significant portion of the L3 spinous process, which was almost laying sideways over the lamina on the left at L3-4. We did a left initially L3 hemilaminotomy, and this converted to an L3 hemilaminectomy since the mass extended up to the insertion of the ligamentum flavum at L2-3. I also removed the superior portion of L4. We found just above the level of the disk space, confirming the MRI scan findings, a large extradural mass that appeared to extend from the facet joint markedly compressing the entire contour of the left L4 nerve root and insinuating itself into the axilla of the L3 nerve root. This was densely adherent to the dura, though with microsurgical technique we were able to separate a fair bit of the capsule from the dura. There were areas where it appeared to be inseparable from the dura, and therefore pieces of the capsule were left attached to the dura. Inside the cystic lesion there was some oily material as we see with synovial cysts but also evidence of multiple staged of hemorrhage, with old hemosiderin-stained material, as well as more recent appearing brownish-reddish material, looking like more recent hemorrhagic events. Again, this appeared to come from the facet joint and I think was a very large synovial cyst. However, it was sent to Pathology for identification. We were able to get the capsule out laterally, but again not entirely medially since in several places it was completely inseparable from the dura. However, the L4 and L3 nerve roots were nicely decompressed, and we could confirm in the axilla of the L3 nerve root there was no further mass lesion.

We then extended up to L2-3 where on MRI scan she had a smaller synovial cyst. We did an L2-3 hemilaminotomy and foraminotomy and indeed found a small synovial cyst just underneath the ligamentum flavum. As we were removing the ligamentum flavum laterally and putting some very slight compression on the thecal sac, we noticed what looked like CSF coming from more medially. I had not any instruments in that area, having no need to do so. Once we completely decompressed the L3 nerve root, and checked both the L2-3 and L3-4 disk spaces, which were flat without evidence of disk herniation, I explored more medially at L2-3. This required removing inferior lamina of L2 and superior lamina of L3. In the midline I found a puncture hole in the dura with arachnoids herniating through, leaking a little bit of CSF. This was surrounded by the white material that we see with epidural steroid injections, so my conjecture is that this was a dural defect caused by the epidural steroid injections that she had had previously.

She had had 2 of them, and apparently each of them were quite difficult, not surprising given her stenosis and severe rotoscoliosis of her lumbar spine. This was leaking, so I had to fix it. I had to take off quite a bit of bone in order to have a good trajectory from the needle. We used 6-0 Gore-Tex on a taper needle, and I was able to get 2 good stitches into the dura. Once these were tightened down, there was complete cessation of CSF leak even with Valsalva.