Bilateral Internal Carotid Artery Aneurysms at the Subpetrosal Portion with Unilateral Lower Cranial Nerve Palsies: Review and Consideration of Surgical Strategy.

BACKGROUND

Symptomatic bilateral extracranial internal carotid artery (ICA) aneurysms at the subpetrosal portion are extremely rare, and their treatment strategy remains unknown.

CLINICAL PRESENTATION: A 42-year-old man presented to our hospital with a 2-month history of sudden onset of hoarseness, dysarthria, and dysphagia. Magnetic resonance imaging, magnetic resonance angiography, and computed tomography angiography revealed extracranial bilateral ICA aneurysms at the subpetrosal portion. The left-sided aneurysm compressed the left-sided lower cranial nerves (IX, X, XI, and XII), whereas the right-sided aneurysm was asymptomatic. We prioritized the treatment of the right-sided aneurysm to prevent bilateral lower cranial nerve deficits. This strategy was used because aneurysm treatment is not guaranteed to cure the left-sided cranial nerve palsies that lasted for 2 months. The right-sided ICA aneurysm was treated with ICA ligation and high-flow extracranial-intracranial bypass using the radial artery as bypass graft. Stent-assisted coil embolization was performed to the left-sided ICA aneurysm after 17 days. The patient showed no right-sided symptoms, and his left-sided symptoms remarkably improved 1 year after surgery.

CONCLUSION

Our unique surgical strategy of prioritizing the aneurysm on the "asymptomatic" side may be one of the best treatment approaches in an extremely rare bilateral aneurysm case.