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[Bilateral agenesis of internal carotid arteries]
Insights
Bilateral agenesis of internal carotid arteries is a rare condition where both internal carotid arteries are absent. This case highlights the complex compensatory blood flow patterns in the brain.
Area of Science:
- Neurology
- Radiology
- Embryology
Background:
- Internal carotid arteries (ICAs) are crucial for cerebral blood supply.
- Agenesis of ICAs is a rare congenital anomaly with few reported cases.
- Understanding variations in cerebral vasculature is vital for diagnosing and managing neurological conditions.
Observation:
- A 76-year-old male presented with right hemiparesis and disorientation.
- Computed angiotomography revealed a left chronic subdural hematoma, dilated basilar artery, and dilated posterior communicating arteries.
- Bilateral internal carotid arteries and their corresponding carotid canals were absent on imaging.
Findings:
- Aortography and brachial angiograms demonstrated collateral circulation via dilated posterior communicating arteries, vertebral arteries, and external carotid artery branches.
- The right common carotid artery and vertebral artery originated from the innominate artery.
- The left common carotid artery and vertebral artery originated from a dilated left subclavian artery.
- Bilateral ophthalmic arteries were supplied by the middle meningeal artery.
Implications:
- This case underscores the importance of recognizing rare vascular anomalies in patients with neurological deficits.
- The findings provide insights into cerebral hemodynamics and embryological development of the Circle of Willis.
- Such anomalies can significantly impact stroke risk and diagnostic interpretation.
Abstract:
The authors present angiographic and computed tomographic demonstration of bilateral agenesis of internal carotid arteries. The patient was a seventy-six years old man who had been admitted to our hospital because of right hemisparesis and disorientation. In addition to the left chronic subdural hematoma, computed angiotomography showed the dilated basilar artery and dilated posterior communicating arteries. However, the bilateral internal carotid arteries were not recognized. Burr hole and irrigation were performed, then neurological deficits and symptoms were disappeared. Hematoma was 150 ml. Though axial transverse computed tomograms of base of skull demonstrated the absence of bilateral carotid canals. On aortography, the right common carotid artery and vertebral artery were supplied from the innominate artery and the left common carotid artery and vertebral artery were supplied from the left dilated subclavian artery. Bilateral retrograde brachial angiograms demonstrated the internal carotid circulation, which was supplied through bilateral dilated posterior communicating arteries. Basilar artery was also in a large caliber. Bilateral ophthalmic arteries were opacified from external carotid artery via the middle meningeal artery. Ten cases of bilateral agenesis of internal carotid arteries have been reported previously. The findings of angiograms and computed tomograms on the agenesis of bilateral internal carotid arteries were discussed. This anomaly is important on cerebral hemodynamics and embryology.