Bilateral internal carotid artery agenesis: a case report

Abstract

Agenesis of the internal carotid artery (ICA) is defined as a congenital absence of the carotid canal and occurs in less than 0.01% of the population. This anomaly is usually diagnosed as an incidental finding or after a cerebrovascular event. We present the case of a 36-year-old woman, with bilateral agenesis of the ICA who had suffered a subarachnoid hemorrhage due to ruptured aneurysm of the basilar artery. Therefore, agenesis of the ICA is a condition that, although rare, should be considered since there is a risk of coexistence with other life-threatening conditions such as aneurysms.Keywords: internal carotid artery; carotid artery diseases; intracranial aneurysm. ResumoAgenesia da artéria carótida interna (ACI) é definida como uma ausência congênita do canal carotídeo e ocorre em menos de 0,01% da população. O diagnóstico dessa anomalia ocorre geralmente como um achado incidental ou depois de um evento cerebrovascular. Apresentamos o caso de uma mulher de 36 anos, hipertensa e tabagista, com agenesia bilateral de ACI, que abriu quadro com hemorragia subaracnoide decorrente de rotura de aneurisma de artéria de basilar. A agenesia da ACI é, portanto, uma condição que, embora rara, deve ser lembrada por estar associada a outras más formações potencialmente fatais, como os aneurismas cerebrais.Palavras-chave: artéria carótida interna; doenças das artérias carótidas; aneurisma intracraniano.

Symmetry, asymmetry and hypoplasia of the intracranial internal carotid artery on magnetic resonance angiography

“…The absence of the ICA occurs in less than 0.01% of the population (4,13). In 2014, Ulger et al (14) stated that 35 cases of agenesis of the ICA had been reported in literature, while Oliveira et al (15) found only 26 cases agenesis of the ICA in literature. In the study conducted by Taşar et al (1) the prevalence of aplasia and hypoplasia of the ICA was 0.13%.…”

Bilateral Agenesis of Internal carotid artery: A case report with emphasis on neuroimaging features

“…Mechanical and hemodynamic stresses placed on the embryo along with comprising effects related to exaggerated folding of the embryo toward one side as well as constriction by amniotic bands are accounted. No explanation for bilateral absence has been rendered in the literature yet [6][7][8].…”

“…Padgett's has proposed that the internal carotid artery originates from the dorsal aorta and the 3rd aortic arch during the early embryonic stage, with the full development of the ICA by 6 weeks [7,8].…”

“…Nevertheless, some controversy regarding the origin of the CCA and ECA is found, some investigators argue that both the proximal ICA and the ECA arise jointly from the 3rd aortic arch and thus agenesis of the ICA is accompanied by absence of the ipsilateral ECA. While others argue that the ECA and CCA can develop normally in the setting of ICA agenesis, as the ECA arises independently from the aortic arch, evidenced by numerous cases of ICA agenesis in the literature with normally developed ECA systems [7,8].…”

“…Less frequently, collateral flow is provided via persistent embryonic vessels or from transcranial collaterals originating from the External carotid artery system [3,4,8].…”