Myxopapillary Ependymoma

December 09, 2015


Myxopapillary Ependymomas most frequently occur in the lumbar thecal sac in the area of the conus medullaris. These lesions are quite satisfying to remove with very positive results after surgery. This is a 62 year old male who presented with progressive low back pain, as well as bilateral L5 radicular pain. And one MRI was diagnosed with a partially cystic mass, partially solid mass, brightly enhancing on MRI within the middle aspect of the lumbar thecal sac characteristic of a myxopapillary ependymoma. On the actual images, you can see that the tumor fills most of the thecal sac with some of the nerve roots displaced more toward the left side, and also, potentially there's evidence of previous hemorrhage within the tumor mass. This patient subsequently underwent a limited lumbar laminectomy over the area of the tumor. I remove the ligament all the way up to the next boney segment, above and below the dural opening, immaculate hemostasis within the epidural space is obtained using gel foam, soaked in thrombin. The dura is open in the midline. And you can see the tumor is very involved with the nerve roots. The most difficult one is going to be this nerve root that is quite adherent to the posterior capsule of the tumor. Before we start dissecting these nerve roots, panoramic exposure of the tumor, relative to the nerve roots by opening the arachnoid membranes is critical. The cystic part of the tumor should be decompressed to provide additional space. You can see if it is not decompressed it would interfere with our dissection. It's quite patchiness and continues to get in the way. One of the assistants is mobilizing the capsule whorl microdissection at the tumor nerve root interface continues. I use a round knife to dissect the arachnoid bands on the periphery of the adherent nerve roots. The raw which is evident at the tip of my arrow. Stimulation mapping is performed to rule out any other nerve roots on the poster aspect of the tumor. This is a very important maneuver by mobilizing the tumor and using very fine forceps to grab the nerve root´s sheath and mobilized the nerve away from the tumor. This maneuver minimizes direct manipulation of the nerve root. Again, you can see another demonstration of this very important technique by using the arachnoid sheath of the nerve root as a handle to mobilize the nerve away from the tumor. Ample amount of irrigation is used to keep the operative field clear of blood, aggressive coagulation is avoided to minimize injury to the nerve roots. One of the smaller nerve root branches that was leading in the tumor was removed at this step. I continued to repeat the same steps to mobilize the arachnoid bands around the tumor, and then use defined forceps to dissect the arachnoid membranes along with the nerve away from the tumor. Here is that peeling off method, using fine forceps, to mobilize the nerve away from the tumor capsule. Some decompression of the tumor would be nice. You can see another nerve root that is somewhat adherent at this stage. Since this nerve was rapping along the poster aspect, I am attempting to completely dissect the nerve first before completing another step involving dissection of the nerves along the anterior aspect of the tumor. Now that the other nerve was dissected, we'll go ahead and start dissecting this nerve, which is also quite adherent. As before, the round knife is used to dissect the arachnoid bands at the periphery of the nerve and define forceps are used to mobilize the nerve away from the capsule. Coagulation is minimized, ample irrigation is used. The tumor is almost free. You can see two roots, both of which are quite significant in size that are being spared. Sharp the section, obviously is as important. This is the phylum that was obviously involved with the tumor. You can see the two large nerve roots that have been spared and look relatively healthy. The dura is closed in a watertight fashion. The fascia is also closed in a watertight fashion. I do not close the muscle very tight because it can lead to necrosis and post operative back pain. This patient did very well after surgery, without any complications. Thank you.

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