I know this thread is a bit outdated but i was also born with my right internal carotid artery. This was found when I was 8 years old after I walked into a mailbox and had an MRI. Nothing really came of it until I was 19, when I was diagnosed with 2 brain aneurysms. The doctors say that I was more at risk for brain aneurysms because of the increased flow in the other arteries. I had brain surgery to clip and coil those two brain aneurysms. I am now 26, have been diagnosed with 2 more small aneurysm that have not been treated yet. I am 8 months pregnant with my first child and hope to have surgery on the two untreated aneurysms soon after my baby girl is born. It is very interesting to me to find other people with this same defect!