The role of the carotid sinus in the reduction of arterial wall stresses due to head movements—potential implications for cervical artery dissection

Abstract

The role of the carotid sinus in the reduction of arterial wall stresses due to head movements--potential implications for cervical artery dissection Abstract Spontaneous dissection of the cervical internal carotid artery (sICAD) is a major cause of stroke in young adults. A tear in the inner part of the vessel wall triggers sICAD as it allows the blood to enter the wall and develop a transmural hematoma. The etiology of the tear is unknown but many patients with sICAD report an initiating trivial trauma. We thus hypothesised that the site of the tear might correspond with the location of maximal stress in the carotid wall. Carotid artery geometries segmented from magnetic resonance images of a healthy subject at different static head positions were used to define a path of motion and deformation of the right cervical internal carotid artery (ICA). Maximum head rotation to the left and rotation to the left combined with hyperextension of the neck were investigated using a structural finite element model. A role of the carotid sinus as a geometrically compliant feature accommodating extension of the artery is shown. At the extreme range of the movements, the geometrical compliance of the carotid sinus is limited and significant stress concentrations appear just distal to the sinus with peak stresses at the internal wall on the posterior side of the vessel following maximum head rotation and on the anteromedial portion of the vessel wall following rotation and hyperextension. Clinically, the location of sICAD initiation is 10-30 mm distal to the origin of the cervical ICA, which corresponds with the peak stress locations observed in the model, thus supporting trivial trauma from natural head movements as a possible initiating factor in sICAD. BM-D-08-00610ROriginalThe role of the carotid sinus in the reduction of arterial wall stresses due to head movements -potential implications for cervical artery dissection

Wall stress of the cervical carotid artery in patients with carotid dissection: a case-control study

“…1A, right), after 45°rotation to the left followed by hyperextension of the neck (Fig. 1B, right), as well as at intermediate positions of the head movements (not shown) (11). Full MRA and MRI details are provided in the study of Callaghan et al (11).…”

“…1B, right), as well as at intermediate positions of the head movements (not shown) (11). Full MRA and MRI details are provided in the study of Callaghan et al (11). MRI in-plane acquisition resolution was 0.8 ϫ 0.8 mm 2 , and reconstructed resolution following zero-filled interpolation was 0.4 ϫ 0.4 mm 2 with slice spacing of 2 mm.…”

“…Thus mechanical factors such as an abnormal increase of focal wall stress may play a pathogenic role in sICAD. Recently, we have reported the wall stress changes observed in the cervical ICA of a single healthy subject assessed with a structural finite element model that used magnetic resonance imaging (MRI) data obtained at different static head positions (45°and 90°rotations, and 45°r otation followed by hyperextension of the neck) (11). We found that wall stress increased at 45°head rotation and was maximal at 90°head rotation and at 45°head rotation followed by hyperextension of the neck.…”

Congenital spine deformities: a new screening indication for blunt cerebrovascular injuries after cervical trauma?

“…As the limit to head rotation is reached, the carotid artery is less compliant and straightens at a lesser rate. This causes localized stress development on the posterior side of the vessel at the internal lumen wall and can ultimately lead to spontaneous intimal tears and arterial dissections in patients with less compliant arteries [8]. Medical conditions causing underlying vasculopathy such as fibromuscular dysplasia, cystic medical necrosis, oral contraceptive use, and recent history of infections change arterial compliance and can predispose patients to spontaneous dissections when minor traumatic force is applied to a less compliant artery [9].…”

Structural and hydrodynamic simulation of an acute stenosis-dependent thrombosis model in mice

“…Arteriole Elasticity 1 (Delfino et al, 1997;Callaghan et al, 2009) Arteriole Elasticity 2 (Gao et al, 2009) W ¼ C 10 ðĨ 1 À3ÞþC 01 ðĨ 2 À3ÞþC 20 ðĨ 3 À3ÞþC 11 ðĨ 4 À3ÞþC 02 ðĨ 5 À3Þþ Á Á Á þ 1 d ðJÀ1Þ C 10 ¼ 5.04 Â 10 4 Pa, C 01 ¼ 3.05 Â 10 4 Pa, C 20 ¼4 Â 10 4 Pa, C 11 ¼1.25 Â 10 4 , C 02 ¼1 Â 10 4 Pa, d ¼4 Â 10 À 6…”