Courtesy F.T. Charbel, MD, Associate Professor, Dept. of Neurosurgery,
University of IL at Chicago
Case Summary
A patient with a giant
anterior communicating aneurysm was referred for treatment. The patient had been operated on at another hospital, but after exposure of the aneurysm, clipping was not
attempted due to the high risk of compromising the left A2. The surgeon used a fenestrated clip on the aneurysm neck which incorporated the left A2 and then placed 2
straight clips directly above it to completely secure the aneurysm. By measuring flow before and after aneurysm clipping, he was able to insure that flow was fully
preserved in the A2 outlet vessels. Multiple clip re-applications coupled with flow measurements, were required to obtain the optimal result and fully preserve left A2
flow.
Step 1. Aneurysm Exposure: the anterior communicating artery aneurysm is exposed. The left
internal carotid artery is the vertical structure on the left. Baseline flows are measured in the left A1.
Step 2. About 1 hour later: baseline flows are measured in the left A2, right A2 and right A1.
Step 3. Dr. Charbel points out the four vessels associated with the aneurysm; he sizes the fenestrated clip against the neck of
the aneurysm. Places temporary clips.
Step 4. Further dissection; the aneurysm is punctured and decompressed.
Step 5. The aneurysm is clipped and the temporary clips are removed.
Step 6.
Post clip flow is measured in the right A2 and left A2. Flow in the left A2 has decreased from a baseline of 29 ml/min to only 2-3 ml/min.
Step 7. The clip is adjusted and left A2 flow is rechecked. After the first clip adjustment left A2 flow is 7-8 ml/min.
Step 8. The clip is taken off. Left A2 flow is rechecked and is 29 ml/min. This measurement confirms that the fenestrated clip
was compromising the left A2.
Step 9.
The clip is reapplied and left A2 flow is rechecked. After the second clip adjustment left A2 flow is 15 ml/min, only 50% of baseline.
Step 10.
The clip is adjusted and left A2 flow is rechecked. After the third clip adjustment left A2 is 33 ml/min, fully restored to baseline. Flow in the right A2 is checked and is 15 ml/min, the same as baseline.
