February 03, 2016
Very rarely I run into large giant and very hypervascular fibrous pituitary adenomas, that present daunting challenges in the resection. Since they often bleed profusely, and they are so fibrous, they cannot be easily removed via the very narrow endonasal corridor. Let's go ahead and discuss the case of such a patient, a 53-year-old male, with visual dysfunction who harbored this giant pituitary adenoma, relatively heterogeneous and potentially eroding through the clinoid in the area of the clivus. I use an extended transfemoral approach. Part of tuberculum was removed, the dura was opened, in a cruciate fashion and you can see the tumor is very bloody, very hypervascular and it's not really responding to the ring curettes in terms of delivering itself. It's very fleshy. The bleeding is quite profuse. We had to use Floseal to get some hemostasis with packing, but every time I remove the packing and attempted resection using various ring curettes, I faced torrential bleeding with really no obvious success to deliver the fibrous tumor. You can see the tumor in this area, actively attempting to remove this tumor and, instead I get some bleeding from the small vessels within the tumor. In this case I aborted the procedure. I felt further continuation would be, not wise. Packing was performed. Hemostasis was obtained as much as possible, and the closure was completed. Here's the extent of hemostasis. Immediately post operative, you can see the extent of my decompression however most of the tumor remains and there's really no evidence of chiasmal decompression. I returned for the second stage of the operation about four days later. I felt that the timing between the two operations would allow the tumor to devascularize itself and some of the tumor capsule will undergo necrosis, and lead to softer tumor that can be easily deliverable. Let's go ahead and review the second stage of this operation. More bone removal was deemed necessary. I unroofed the dura over the cavernous sinuses bilaterally. More of the tuberculum was also removed. This time the tumor appeared much softer as you can see, although not very soft, it's definitely much softer than the tumor I encountered during the initial operation. Once the, lateral portions of the capsule were delivered, you can see the more anterior part of the capsule also descended into the resection cavity. So the steps involved first, lateral removal of the capsule of the tumor, then posterior removal of capsule, and then, removal the capsule more anteriorly. The order of these steps, prevents early descending of the diaphragma sellae, therefore diaphragma will not interfere with removal of the tumor along the lateral aspect of the resection cavity. You can see the capsule is somewhat fibrous. It required pituitary rongeurs for its removal. The capsule had to be cut in certain points to allow its delivery, therefore, this is really not a usual pituitary adenoma resection. It required additional more aggressive techniques and the endoscope allowed a more expanded visualization of the operative space, so that these risky maneuvers can be performed relatively safely. Here's the diaphragm that is being detected and is descending into our resection cavity. Irrigation is done so that the surrounding structures are more curly identified. More of the tumor along their lateral sellae is being delivered, into our resection cavity. Again the tumor is somewhat hypervascular, but this time it's much more manageable. We can use the ENT debrider to remove the very fibrous portion of the capsule that is easily visualizable. Obviously blind use of any sharp technique is avoided. Here's the debrider or the ultrasonic aspirator that can be used to remove the very fibrous portion of the capsule, so that the diaphragm can descend further. Irrigation is completed to further clear the operative field. You can see the diaphragm is only partially descended so this means that there is some residual tumor more superiorly and posteriorly. I continue to, use the bimanual dissection technique to deliver the fibrous portion of the tumor that is keeping the diaphragm still elevated. Here is additional part of the soft tumor that is evident. Patience is quite important. Valsalva maneuvers may be used to further force the diaphragm inferiorly, leading to the delivery of the tumor into the resection cavity. Lumbar drain and injection of air is another alternative method, for making the diaphragm descend. Ultimately, patient maneuvers, careful inspection of the folds of the diaphragma sellae are both important techniques for removal of those portions of the tumors that are not easily visualizable. Using angled endoscopes, I'm able to, again dissect around the faults of the diaphragms sellae, carefully, removing the tumor without tearing the diaphragma. Here's a small part of the tumor that is very adherent to the diaphragm. Again as the diaphragm descends into the sellae, it can be quite difficult to work around it. I use the suction to hold the diaphragm up and work through the gutters, assuring myself that the gross total resection of the mass is achieved. See the diaphragm is quite patchoulis. This is expected in this very large tumor. I assure myself that there is no portion of the tumor that's left behind laterally within the blind spots and including anteriorly just underneath the tuberculum. Here's the dynamic retraction of the diaphragm and inspection via the angled endoscopes, and around the blind operative spots, that can be quite challenging to visualize under normal circumstances. No obvious tumor is evident. I'm satisfied with the extent of resection in this case. I assure myself that there no tumor especially more posteriorly. The diaphragma essentially filling the entire sellae, providing additional confirmation that the tumor is completely removed. I used a large piece of fat to buttress the herniating diaphragm. Again Occult CSF leaks are possible in these cases and, these occult leaks can only show themselves post operatively. A piece of allograft dura was also removed to reconstruct the floor in this case and due to the use of the expanded transsphenoidal technique we use a nasoseptal flap to reconstruct the floor of the sellae and minimize any risk of post operative CSF leakage. Here's use of Surgicel to further buttress and keep the nasal septal flap in place. Using some glue to further buttress the whole construct, and the post operative MRI in this case demonstrated the desirable result and gross total removal of the mass with adequate decompression of the optic apparatus and this patient's vision improved significantly post operatively, thank you.
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