ICA+Occlusion+with+Collateral+Pathways

Which posterior coursing ECA branch may supply blood to the posterior circulation? Explain: Emily: The Occipital branch of the ECA would supply blood to the posterior circulation. Blood would flow from the ECA to the Occipital Artery, to the vertebral artery, which would bring blood into the Basilar Artery and to the PCA's.

Madeline: One of the first branches that comes to mind is the occipital branch of the ECA. The occipital branch originates off of the ECA and courses posteriorly to the back of the head. In order for this to be a collateral, blood would flow into the ECA, into the occipital artery, vertebrals, basilar and then into the posterior cerebral artery.

What is missing? How could a complete circle of Willis help this patient? Describe: Jess: The left CCA is missing. It would fill from the right side via the anterior communicating artery to the ACA/MCA retrograde to the left ICA. From there, the left ICA can supply blood to the brain.

Ashley: The Left CCA is missing in this scan. The full circle of willis would help provide blood to the left side of the circle of willis through the anterior communicating artery to the left anterior cerebral artery and to the middle cerebral artery and then can flow retrograde into the left distal ICA potentially all the way down to the left ECA to even help feed the face, depending on the extent of the occlusion in the CCA.

An occluded ICA on the right side could create and internalized ECA. How does the ECA waveform change? What is the new direction of the opthalmic artery, relative to the eye? Jess: The ECA takes on some of the ICA characteristics by becoming more low resistive. The opthalmic artery is now retrograde flow that is being filling by the frontal artery via the facial artery due to the ICA occlusion. Picture B Danielle: When the ECA is internalized it takes on the waveform of the ICA because the ICA is occluded so the ECA is acting as the pathway for blood to get to the brain. The waveform would be low resistive instead of its normal high resistive characteristics. The opthalmic artery would now be retrograde, away from the eye to feed the brain. Ashley: The ECA waveform that is internalized because of the ICA occlusion is more low resistive instead of high resistive like the normal ECA. It takes on the waveform of the ICA so it can help feed the vital structure in the head, the brain. The new direction of the opthalmic artery will be away from the transducer or retrograde. This is fed by the facial artery branching from the ECA when this collateral is formed.

Tatyana: If the ECA becomes internalized in case of ICA occlusion, sonographically it would show more low-resistive pattern with more diastolic flow. The blood flow in the ophthalmic artery in this case would be changed to retrograde direction.

Here the superficial temporal artery is connecting to the? to retro fill the?

Michayla: The superficial temporal artery is connecting to the supraorbital artery to retro fill the opthalmic artery in order to feed the ICA and the brain.

Jen: Usually, blood is supplied to the opthalamic artery from the ICA. Because of the aneurysm at the opthalamic artery orgin, the blood is going CCA>ECA>Superficial Temporal>Supraorbital and flowing retrotrade. If a transorbital Doppler was performed, the blood would be going away from the transducer, instead of the normal antegrade flow.