This video reviews techniques for clip ligation of large ICA bifurcation aneurysms, and also summarizes the tenants for dissection of the Sylvian fissure. This is a 32 or female who represented with an incidental 15 millimeter right-sided ICA bifurcation aneurysm and a very small anterior Choroidal artery aneurysm. You can see the location of the anterior choroidal artery aneurysm. The large ICA bifurcation enters and is relatively bi-loped. It is pointing straight cranially and the relationship of the neck of the aneurysm to A1 and M1 is demonstrated A right frontotemporal Craniotomy was completed. The area of the Pterion was drilled away and the latter aspect of this sphenoid wing was removed. Let's go ahead and review the basics of splitting of the Sylvian fissure. The thick, superficial arachnoid bands are first in size using a sharp arachnoid knife. Next I like to use Jeweler forceps to carefully avulse the thick, superficial arachnoid bands while protecting the in-cased or underlying superficial sylvian veins the dominant superficial Sylvian vein is left on the temporal side of the fissure. You can see that I grabbed the arachnoid bands and tear the arachnoids layers from distal to proximal direction. This is a very efficient method. Next, the vein is mobilized again, toward the temporal side. The van can be quite adherent at certain locations on the frontal operculum. Bipolar coagulation should be minimized as much as possible. Although at times this maneuver may be necessary, As the superficial arachnoid bands are dissected. The deeper bands are easier to dissect. Next. I do the inside to outside technique to dissect the fissures. You can see that more distally. I extend my splitting all the way to the surface of the insula And the M2 branches. This spreading action of the bipolar forceps is used to separate the thin arachnoid bands. Now that the surface of the insula is identified the dissection proceeds from the inside to outside technique. Occasionally one or two bridging final veins have to be sacrificed Dissection along the anterior aspect of the Cerebral fissure can be quite challenging specially in the area of temporal Polari patients and sharp dissection are the most key principles for a traumatic dissection of the Fissure. Here's the superficial sylvian vein turning anteriorly along the entry aspect of the temporal lobe. The arachnoid bands over the door of the lesser sphenoid wing are also being dissected until the internal choroidal artery is visible. Here's the artery, Optic nerve. Just a little bit more medial to that. Again, further dissection of the medial limb of the sphenoidal segment of the fissure is necessary for disconnection and.. of the frontal and temporal lobes. The superficial sylvian vein remains intact. Here's the optic nerve on the right side. The suction device is used as a vector of dynamic retraction Irrigation clears the operative field aggressive suction on the neurovascular structures is avoided. This generous mobilization of the frontal lobe prevents the use of fixed retractor plates. Here's the A1 just over the chiasm. Here's the small anterior choroidal artery as expected Before clipping the anterior choroidal artery, we'll focus our attention on the larger aneurysm, Which is the ICA bifurcation aneurysm. We want to make sure that the larger clip plates will not interfere with the smaller clip, which will be necessary to occlude the anterior choroidal artery aneurysm. Here. You can see the anterior choroidal artery. Let's go ahead and attempt to take care of the ICA bifurcation aneurysm first here's the ICA along the level of the skull base, here's the M1, Temporal clip is used proximal to the anterior choroidal artery. Here. You can see the picalm. The medial part of the sac is mobilized. Here's the M1 the ICA bifurcation. Here's the A1, You can see the A1 more clearly now. A temporal clip is also placed across the dominant A1 to allow more deflation of aneurysm SAC, and it's dissection away from the medial vital perforating arteries, Can see the M1 is tethering the bifurcation here you can see the perforating vessels I'm dissecting all the way along the pathway of the clip plates Making sure no perforating vessel such as the one, there will be compromised by the blades. blind dissection Using the clip lights is prohibited. I can see all the way to the A1 origin. I use a straight fenestrated clip on an angled clip applier To close the distal neck of this large aneurysm. I patiently advanced the clip blades while assuring preservation of all the dissected perforating arteries. The origin of A1 is also protected. The use of temporary occlusion provides the ability and safety of high-risk maneuvers to dissect the sac. and also provides an opportunity for nice reconstruction of the neck. Here, You can see good flow on the parent vessels using fluorescein angiography, Perforating vessels appearing tact. The aneurism, at least initially did not appear to be filling further. Our ICG angiography, also appeared to be confirmatory in terms of exclusion of the aneurism. However, with time you can see the aneurysm is slightly filling. Before I place a second clip on the ICA. I went ahead and clip occluded the anterior choroidal artery. You can see with time, they fluorescein also fill the aneurysm sac again, confirming the fact that the aneurism is sub optimally excluded. Here's a small clip across the neck of the anterior choroidal aneurysm. I wanted to make sure this aneurism clip will not interfere with placement of the second clip across the ICA bifurcation. Here's a straight clip closing, the more proximal neck of the aneurysm. ICG angiography demonstrated complete exclusion of the aneurysm. Without any further filling with later phases of the ICG angiogram Here. You can see that the fluorescein unfortunately remains within the vessels much longer than the ICG. And therefore these two angiography methods are more complimentary in terms of the fact that one can be done first, and if there's evidence of filling, additional clips can be applied and another mode of angiography can be used so that the dye filling their vessels from the first agent will not interfere with the results of angiogram. In this case, the post operative arteriogram demonstrated complete exclusion of both aneurysms without any compromise of the surrounding parent vessels. And this patient recovered from her surgery without any deficits. Thank you.
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