December 22, 2015
Resection of spinal cord hemangioblastoma is quite satisfying. This video reviews the techniques for such a resection. This is a 32-year-old male who presented with six months history of progressive myelopathy. And an MRI evaluation was noted to have a relatively homogeneously enhancing mass on the posterolateral aspect of the spinal cord leading to a sizable syrinx. The nodule is located just on the surface of the syrinx on the posterior aspect of it as you can see here. It is important to know that the syrinx can lead to a false localizing sign and therefore additional neuro access imaging may be necessary to identify a nodule that is asymmetrically located along the ends of a syrinx. After a generous laminectomy, the dura was exposed facetectomy, or partial facetectomy on the left side was extended to be able to have an orthogonal operative angle toward the posterolaterally located nodule. This is the caudal or the feet area, and this is the cranial or the area leading to the location of the head of the patient. Partial facetectomy was completed on the left side, and epidural hemostasis was carefully attained. For lesions that are located on the anterior or anterolateral aspect of the spinal cord, partial pediculectomy can be quite effective to provide adequate space for reaching the anterior aspect of the spinal cord. A midline durotomy is completed and the hemangioblastoma and the associated large draining veins are exposed. The arachnoid bands over the lesion are opened. Here, you can see the nodule of the hemangioblastoma that is well demarcated from the surrounding pial membranes of the spinal cord. You can also appreciate the draining veins associated with this lesion. Obviously, these draining veins are preserved until the end of the operation. There are a number of steps involved with resection of hemangioblastomas including the initial step of arachnoidal dissection. Since this lesions are primarily epipial, therefore the parenchyma should be minimally transgressed for the removal and the dissection should be primarily left within the juxtapial space. The feeding arteries are initially transected, the draining veins are protected. The nidus is isolated, and ultimately, the draining veins are disconnected and the lesion is removed. Essentially, the dissection process is very similar to a simple arteriovenous malformation. If a portion of the hemangioblastoma enters the parenchyma, I may leave that small portion within the parenchyma to avoid injury to the surrounding neural structures within the parenchyma of the spinal cord. I do use somatosensory-evoked potentials and motor-evoked potentials during the operation. These neurophysiological monitoring techniques guide the retraction or retention sutures that may be needed to be placed on the pia and also guides the amount of retraction, in other words, dynamic retraction that may be necessary for removal of these lesions. If the dynamic retraction of the suction device leads to some changes in the neurophysiological monitoring, these maneuvers are adjusted to avoid any permanent injury to the spinal cord. Mild changes in the neurophysiological monitoring parameters may not be very useful if the lesion has to be completely resected, and it's well-defined if these neurophysiological changes are only temporary. So, I will continue my dissection, as you can see, along the periphery of the capsule using bipolar cautery. Along the ends of the resection cavity, especially at the edges of the syrinx, small myelotomy may be necessary to be able to expose the nodule with our significant retraction on the spinal cord. The nerve roots have to be also mobilized in the thoracic area, or one or two of the nerve roots may have to be sacrificed. Here is the coagulation of the pial surface adjacent to the capsule of the tumor. The margins of the lesion are coagulated and the feeding vessels are transected. The gliotic margin is identified and the dissection and circumferential isolation of the lesion remains just on the periphery of the nodule, as you can see here. Here's the discolored pial surface around the tumor capsule. Ultimately, the nodule is removed after the veins are disconnected. The dural closure is conducted using a piece of dural allograft if watertight primary closure can lead to potential pressure on this spinal cord. This patient recovered from his surgery without any complication and has since recovered also some of his functions related to his myelopathy. Thank you.
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