Answer for BIR CoW 21 Apr 2024
Double steal phenomenon
Findings
There is partial reversal of flow in right internal carotid artery and complete reversal of flow in right vertebral artery- double steal phenomenon- indicative of a brachiocephalic occlusion- should be confirmed with a CT angiogram.
Discussion
Carotid angiogram from the arch showed dense calcified atheromatous plaque at the origin of right brachiocephalic trunk with poor opacification of right subclavian and common carotid in the first phase and normal contrast opacification in the second/venous phase. Double steal phenomenon is a rare condition where occlusion of the innominate (brachiocephalic) artery leads to hemodynamic changes in which blood flow is shunted from the intracranial circulation down the right vertebral artery and subsequently up the right carotid and subclavian circulation. This results in hypoperfusion of the right carotid, subclavian and vertebral circulation, putting patients at risk of both posterior and anterior circulation ischemic events. Therefore, early diagnosis with CTA is critical. Duplex scanning may show right vertebral artery flow reversal, diminished subclavian flow, and several patterns of right carotid flow disturbance, including slow flow, partial flow reversal during the cardiac cycle and even complete reversal of flow in the internal carotid artery.
Findings
There is partial reversal of flow in right internal carotid artery and complete reversal of flow in right vertebral artery- double steal phenomenon- indicative of a brachiocephalic occlusion- should be confirmed with a CT angiogram.
Discussion
Carotid angiogram from the arch showed dense calcified atheromatous plaque at the origin of right brachiocephalic trunk with poor opacification of right subclavian and common carotid in the first phase and normal contrast opacification in the second/venous phase. Double steal phenomenon is a rare condition where occlusion of the innominate (brachiocephalic) artery leads to hemodynamic changes in which blood flow is shunted from the intracranial circulation down the right vertebral artery and subsequently up the right carotid and subclavian circulation. This results in hypoperfusion of the right carotid, subclavian and vertebral circulation, putting patients at risk of both posterior and anterior circulation ischemic events. Therefore, early diagnosis with CTA is critical. Duplex scanning may show right vertebral artery flow reversal, diminished subclavian flow, and several patterns of right carotid flow disturbance, including slow flow, partial flow reversal during the cardiac cycle and even complete reversal of flow in the internal carotid artery.
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!