Identification of the Free Edge of the Tentorium on the Contralateral Side
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In this segment, the tentorium is further opened, tumor removal is continued, and vein of Galen is dissected free from tumor.
- Vein of Galen
- Straight sinus
About this video
- Giuseppe Cinalli
- Matteo Sacco
- First online
- 16 March 2019
- Online ISBN
- Springer, Cham
- Copyright information
- © The Author(s) 2019
Here we proceeded to further opening of the tentorium and tumor dissection and removal on the contralateral side. We identify the tumor that is on the contralateral side of the posterior fossa, hidden by the tentorium. We understand that we have to increase significantly the opening of the tentorium.
And we proceeded with the technique of the contact laser that allows to expose the tumor very nicely. And we can open the tentorium by vaporizing the dural tissue, at the same time obtaining an excellent coagulation effect. We have to be careful of not injuring lateral lacunae of the straight sinus.
And after this large tentorial opening, we continue the internal debulking of the tumor that is falling from the contralateral side. And that looks easy to dissect from the contralateral tentorium.
We explore inside the tumor in order to verify the presence of big vessels inside the tumor that could make difficult the tumor removal. And then we proceed to the internal decompression, and at the same time, a dissection of the arachnoid plan of the tumor that is attached to the neural tissue and to the veins on the contralateral side of the posterior fossa.
This internal decompression is very important in order to facilitate this further maneuver of dissection of the tumor capsule. Fortunately, there is a nice arachnoid plan that allows to identify, again, the vein of Galen at this level.
And that allows to check the absence of apparent infiltration of the tumor in the wall of the vein of Galen the presence of a nice dissection plan at this level. So we can continue the dissection posteriorly of the vein. And also inside the tumor, we can continue in the decompression strategy in order to facilitate in the following steps the activity of dissection.
We check frequently the presence of internal large vessels inside the tumor. And we understand also that the very large part of the tumor is still hidden by the tentorium. And for this reason, we decide to continue the opening of the tentorium in order to achieve the largest possible view of the contralateral side of the posterior fossa.
The anatomy is very clear. We remain quite far from the straight sinus, as you can see, in order to avoid significant bleeding from the tentorial dura. And we continue with this vaporization of the tentorial dura in order to obtain the best possible vision of the contralateral attachment of the tumor.
With very careful dissection, we arrive, finally, to the identification of the contralateral tentorium. And at this level, we are quite far from the original point of departure. And we have to achieve a better tumor internal decompression and debulking in order to facilitate the dissection maneuvers.
So at this time, we address the central core of this tumor mass. And we identify, again, a plan where we can separate the significant part of the tumor, where we can coagulate diffusely in order to shrink this large tumor mass.
And after coagulation and shrinking, we can progress to quite fast and precise aspiration with the ultrasonic aspirator in order to remove the largest possible component of the tumor from inside the capsule before attempt to further dissection of the tumor from outside this capsule.
The tumor is very heterogeneous. The capsule is very firm, as you can see in these images, but can be fragmented and aspirated by the ultrasonic aspirator with a power that remains in an average of between 50 and 70 of the cavitation power and of the sucking power.
And this is effective anyway in obtaining an excellent reduction of the internal part of the tumor. This part, of course, can be very tedious because the tumor is very big. And we do not want to proceed very quickly because of the risk of significant bleeding that, at this age, should be absolutely avoided.
We, clearly, proceeded slowly with the superficial attack to the tumor in order to avoid the risk of entering too deep inside the tumor without the control of the tip of our instrument. If we remain superficial to the tumor, and we proceed to further horizontal layer decompression, we can keep the control on the tip of our instrument.
And we create the large opening that make easier the aspiration of the blood with the sucker in the contralateral hand. And we can have under control a large area of the tumor, instead of inserting the instrument too deep into the tumor, losing the control of the tip, and losing the vision of where the tip is working and taking too many risks of vascular or a neural injury with the Cavitron.