**4. Other related predisposing risk factors**

Atherosclerosis is a series of complex events that can begin in early fetal life [3, 4, 16, 26]. The onset of atherosclerosis was implied to be connected with several risk factors such as diabetes, genetics, and so on [4, 26]. Such as aorta abdominalis, bifurcation regions have been mentioned as primary locus that is prone to atherosclerosis [6, 20]. In recent studies, it has been suggested that the vessel diameter and area ratios are hypothetically important elements of plaque improvement [9, 20, 23]. With this information in mind, it earlier-published findings have been continued [6, 17], by observing the characteristics of vessel positioned in the bifurcation regions in young cadavers [6, 11, 13, 27].

**2. Structural physiognomies of the common carotid artery (CCA) and** 

have a collision on the beginning of atherosclerosis [3, 5, 6, 13].

**3. The correlation between area ratios and the histological** 

**characteristic of cerebral vessels of newborn cadavers**

been inspected in some studies.

**4. Other related predisposing risk factors**

Blood vessels and their luminal physiognomies have long been questioned as additional risk factors for atherosclerosis referring their stimulus on blood flow [9, 13–15]. Some arteries are more predisposed for the onset of the atherosclerotic plaques on the endothelial surface [2, 4, 10, 15, 16]. Current studies specified that the variations in the luminal diameter of the vessel

Carotid artery is one of the two main vessels that stream blood to brain. Obstruction in the carotid artery leads to erosion and causes some brain symptoms. The anatomical elements of the common carotid artery (CCA) and its branches receive attention from researchers and clinicians, referring their scientific and clinical results. Also, another important factor is their involvement in plaque formation [7, 8, 10, 13, 17–21]. Hence, it is essential to distinguish the anatomical topographies of the CCA and its branches. CCA divides into two branches, that is, internal carotid and external carotid arteries. Atherosclerosis progresses mainly at bends and major branches of the arterial network, such as the carotid bifurcation and its subdivisions [2, 3, 15, 17]. Alike other bifurcation of large vessels, carotid bifurcation at the neck region is more prone to the initial growth of atherosclerotic plaques [3, 6, 14–16]. Flow models suggest that vessel anatomy, in particular vessel diameter and area ratios, affects plaque formation at arterial bifurcations. The carotid bifurcation is one of the most common of atherosclerotic plaques [2, 3, 9, 20, 22]. Therefore, assessing the diameters of the CCA, internal, and external carotid arteries (ICA and ECA) is important for evaluating the pathological changes [6, 22–25].

Despite the progression of atherosclerosis with aging being widely studied, there are limited studies in newborns. Many studies evaluated the diameters of peripheral vessels in adults, but only few studies were conducted on CCA and its branches in newborns [3, 6, 12, 19, 22]. Thus, an early beginning of atherosclerosis is suggested to initiate in the early period of life. Then, the purposefulness was to scrutinize the anatomical and histological characteristics of cerebral vessels in newborn cadavers. Consequently, it has been hypothesized that variations in carotid bifurcation lumen geometry would be the self-regulating prognosticators of ICA atherosclerosis, aiming to reveal the early beginning of atherosclerosis in newborn cadavers. The relation between the endothelial destruction and the outflow to inflow area ratio was also

Atherosclerosis is a series of complex events that can begin in early fetal life [3, 4, 16, 26]. The onset of atherosclerosis was implied to be connected with several risk factors such as

**its branches**

22 Atherosclerosis - Yesterday, Today and Tomorrow

As specified in the study, a vessel diameter and area ratio (score) are approximately 1.15 [12]. Low ratios could be reflective of increased local stress and endothelial damage. As a predictable result, the endothelial reaction to the damage might be amplified permeability accompanied by monocyte adhesion and migration.

The diameters of the CCA, ECA, and ICA have again been analyzed in the recent studies. The relative vessel dimension was shown to be significant in the progress of the disease [6, 11, 13, 19, 27]. Consequently, ICA/CCA, ECA/CCA, ECA/ICA ratios as well as the outflow to inflow area ratio have been calculated. Furthermore, vessels have been histologically evaluated using histo-staining methods and scanning electron microscopy (SEM) to determine the extent to which atherosclerotic pathology exists, if any [3]. The other central aims were to calculate the mean diameters of CCA, ICA, and relationships between atherosclerosis and ECA and outflow to inflow area ratio in the newborn period group. These records can be of use in intravascular composition and also for understanding the changes in these vessels that occur in fetal life [3].

The substantial intra-individual and inter-individual alterations of the carotid artery have previously been publicized in some studies [6, 9, 11, 13, 16, 20, 27]. Recently, it has been tried to discover the answer whether these differences were present in the early period of life [3].
