Introduction Extracranial carotid artery pseudoaneurysms are rare and have high mortality rate with rupture. There is no treatment-guideline due to rarity and heterogeneity of cases.

Aim of Study We report a man presented with neck swelling, diagnosed as infectious giant pseudoaneurysm.

Methods A 76-year-old man admitted because of fever and neck swelling . He presented high fever and CRP level, with history of Covid-19 a month ago. Neck CT showed deep neck infection with enhanced lesion around left ICA. MRA showed a large pseudoaneurysm of left ICA. Cerebral angiogram confirmed a giant pseudoaneurysm of left proximal ICA. There was no collateral flow across Circle of Willis, even when compressing left CCA.

Results Endovascular treatment was chosen over surgery considering infection. Covered stenting was attempted, but failed to pass through curvature of CCA-ICA junction due to stiff device.

Surgery could not be considered because infection was not controlled despite antibiotics. After CRP was normalized, second treatment option using flow diverter was attempted.

Angiogram revealed dramatically increased size of pseudoaneurysm and severe narrowing of ICA distal to psueodoaneurysm, thought to be a mass effect by pseudoaneurysm. The catheterization to aneurysmal outflow failed continuously due to narrowing.

As the last option, we decided surgical treatment. Bypass through CCA-artificial graft-distal ICA was performed.

Conclusion When we deciding treatment strategy, surgery could not be considered due to uncontrolled infection and suggesting inflammatory/erosive changes. Because of no collateral flow, carotid sacrifice could not be considered. Endovascular treatment is preferred option, but treatment strategy should be personalized.

Disclosure of Interest Nothing to disclose