April 28, 2016
This is a short video describing technical tenons for clip ligation of a small proximal PICA aneurysm. This is a 52 year old female who previously underwent endovascular coiling of her ruptured basilar bifurcation aneurysm. And it was also noted to Harbor and incidental, small right PICA aneurysm. You can see the location of the aneurysm, primarily at the level of the vertebral PICA junction. The aneurysm is slightly multilobulated. Patient underwent a right-sided, lateral suboccipital craniotomy. You can see the use of a hockey stick incision. The extent of bony removal, as well as dual exposure, and condylectomy non-necessary in this case. The dura can be opened in a slightly S shaped fashion. Only a small dural exposure or incision is necessary for completion of this procedure. The hockey stick incision effectively mobilizes the myocutaneous flap out of our working zone. And I prefer this skull flap for this advantage. After dura is opened, the edges of dura are mobilized. You can see the area of the cranial cervical junction. Arachnoidal dissection continues to dissect the arachnoid bands. Release additional CSF and find the entry point of the vertebral artery into the posterior fossa. After the Irie is identified, I continue dissection along the artery until more of the lower cranial nerves and additional anatomical landmarks are under vision. Gentle mobilization of the cerebellum will expose the PICA. Here you can see the PICA the vertebral artery. The aneurysm would be located at this Junction. I would expect the hypoglossal nerve to be just straight over the aneurysm. In this case, here is the nerve itself. Here's the neck of the aneurysm. Generous dissection of the arachnoid bands or mandatory. So all the neurovascular anatomy is carefully recognized. Identification of the distal part of the vertebral artery can be challenging, because it is turning medially and away from us. You can see the hypoglossal nerve is carefully mobilized. And the distal part of the artery is carefully recognized. Here's a more demagnified view of our operative corridor. Again, the XII cranial nerve. PICA proximal vertebral, distal vertebral. It is just the bottom view. As you can see here as these arachnoid bands are released. Premature placement of the clip can lead to occlusion of any of these vessels. Here is the distal part of the vertebral artery. Again, moving away from us medially toward the ventral brainstem. Here's the multiloculated aneurysm. One more time vertebral artery. Distal vertebral artery, origin of the PICA. The artery is carefully mobilized. Aggressive retraction on the brain stem is avoided. Now we have a nice view of the aneurysm and all its lobules. Here is further exposure of the neck and the belly of the aneurysm. Aneurysm itself. It's medial neck, the origin of PICA, as you can see, ample amount of time is spent to recognize the anatomy. Carefully understand where the clip plates will be placed. Blind dissection, using the tip of the clip plates is prohibited. Temporary clip on the vertebral artery may be used. If necessary, here is an angled fenestrated clip. A right angled fenestrated clip. You can see the PICA placed within the fenestration. And the blades closed, the neck enters and very effectively. In this case, the blades are closing and collapsing the neck parallel to the parent vessel. And this is a very physiologic and effective vector or methodology to close the neck. Doppler ultrasonography confirms adequate flow. Here's the neck of the aneurysm that was excluded. Here's the proximal vertebral artery. Distal vertebral artery, origin of the PICA. fluorescein and ICG angiography, both reveal excellent exclusion of the aneurysm without any complicating features in very narrow operative corridors under high magnification. Fluorescein angiography provides certain advantage, over ICG angiography. Again, a more demagnified view, placement of the clip. Basically the aneurysm that is excluded distal part of the vertebral artery. You can see a more, demagnified view of our final operative corridor. A closure is performed standard fashion. And the intraoperative angiogram demonstrated complete exclusion of the aneurysm with patency of the surrounding vessels and the postoperative imaging revealed similar findings. Thank you.
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