More Videos

Highly Atherosclerotic PCoA aneurysm: Clip Deployment

January 05, 2016


I would like to emphasize a few important points regarding clip ligation of posterior communicating artery aneurysms, especially the ones that are highly atherosclerotic using this short video. This is a 54 year old female who presented with a seven millimeter incidental right-sided posterior communicating artery aneurysm. You can see the morphology of the aneurysm on the right side, it's relatively typical. There is no evidence of calcification within the walls of the aneurysm. Patient underwent through right frontotemporal craniotomy. This is one of my older videos, where I used fixed retractors. The anterior limb of the Sylvian fissure, or the sphenoidal segment, was carefully dissected. The frontal lobe was gently elevated Here you can see the sharp dissection preserving the veins, or the anterior aspect of the Sylvian fissure. Subsequently dissection was extended more medially toward the optic nerve, where the optical carotid cisterns are open, and additional CSF was released. Here is the optic nerve, carotid artery, look here, just slightly posteriorly. Here's the thick arachnoid band along the most medial aspect of the Sylvian fissure joining the optical carotid cisterns. You can see that extensive dissection of the fissure is not necessary. Next, the sub frontal area is released, or disconnected from the optic nerve and the chiasm, so that the frontal lobe can be mobilized easily, and the carotid artery exposed. A round knife is quite effective for this purpose. The carotid artery appears very atherosclerotic, is essentially yellow in its entire circumference. This means that proximal control, is most likely not available, since the temporary clips would not be closed upon their application. So here is the ICA, here's the aneurysm. Here's the portion of the ICA just, distal to the aneurysm, the aneurysm is projecting postero-laterally as expected. Next, I would like to find the origin of the anterior carotid artery, as was the origin of the Pcom. You can see the third nerve there. Here's the origin of the anterior carotid artery, the distal neck of the aneurysm. More immediately, the Pcom is apparent. This is the first configuration of clip application perpendicular to the ICA. I do not believe this is a good idea, especially in highly atherosclerotic aneurysms the clip blades may not close, and suboptimal clipping may lead to premature rupture. Therefore this is not advised. The next possible configuration is again, perpendicular to the axis of the ICA, and this method also suffers from same dangers and risks. The most ideal method for application of the clip is parallel to the long axis of the ICA, as you can see here, tilting the clip slightly so that the origin of the Pcom is protected. You can see the blades are as parallel to the axis of the ICA as possible Physiologically this is the best method to collapse the neck effectively. The Pcom appears patent based on micro doppler ultrasonography. The neck appears completely collapsed. Let's go ahead and do ICG angiogram to better confirm the findings of the micro doppler probe. The aneurysm is not enhancing. The ICA is patent. The Pcom, that you can see just medial to the carotid wall is also patent here's the final results. In a demagnified view of the operative corridor. Postoperative angiogram confirmed complete exclusion of the aneurysm without any undesirable findings, and this patient made an excellent recovery. Thank you.

Please login to post a comment.

You can make a difference: donate now. The Neurosurgical Atlas depends almost entirely on your donations: donate now.