Dorsal internal carotid artery (ICA) blister aneurysms are an uncommon aneurysm variant constituting 0.3% to 1% of intracranial aneurysms and can be due to ulceration, atherosclerosis, or dissection.1-3 Despite its rarity, it carries a high risk of rupture with an estimation of 0.9% to 6.5% among intracranial aneurysms.1,2 Blister aneurysms are small in size, have no distinguishable neck, and have a friable wall that can easily rupture if manipulated, hence the difficulty in its treatment utilizing both microsurgical and endovascular techniques.1,2,4-6 Endovascular coiling of these lesions may not be adequate due to the broad-based size; stenting requires the use of antiplatelet medications, which could lead to rebleeding; flow diversion takes longer to exert its treatment effect.1,4 Conversely, microsurgical management carries a higher intraoperative rupture rate.2 Microsurgical options include clipping, clip reconstruction, trapping with bypass, and wrapping.4,7 We present a case of a 38-yr-old man who presented with a ruptured right dorsal ICA blister aneurysm treated with microsurgical trapping with intraoperative flow measurements. We demonstrate how the use of quantitative intraoperative flow measurements allows confident sacrifice of the supraclinoid ICA. We also demonstrate in contrast another case example of utilizing a clip-graft repair. The patient remained unchanged with an intact neurological exam, and postoperative imaging showed no aneurysm remnant and patent anterior choroidal artery. We review the literature and management of dorsal ICA aneurysms.8-15 We also review the technical nuances and different endovascular and microsurgical treatments that can be used for this condition.
The patient gave informed consent for the procedure and verbal consent to the publication.