Cardiovascular Engineering and Atherosclerosis Laboratory, 1st Cardiology Department, AHEPA University General Hospital, Aristotle University Medical School, 1 St. Kyriakidi Street, Thessaloniki, Greece.
EuroIntervention. 2010 Dec;6 Suppl J:J16-23. doi: 10.4244/EIJV6SUPJA4.
Coronary bifurcations are among the most frequent sites affected by atherosclerosis. In these regions, complex haemodynamic conditions prevail and local flow disturbances dictate the localisation and progression of atheroma. Endothelial shear stress (ESS) is the main flow-related factor affecting the distribution of atherosclerosis in a bifurcation. Plaques are more prevalent in low ESS areas, such as the lateral walls of the main vessel and side branches, while they are less common in the flow divider or carina, which is characterised by high ESS. However, the carina is not free of atheroma and is affected in up to one third of cases, but never in isolation. Lesions in the carina are likely to develop at a later stage of atherosclerosis, as result of circumferential expansion of plaques from the lateral wall. Pulsatile flow augments the local atherogenic environment by inducing low and oscillatory ESS. The geometrical configuration is also important as increased curvature and wide angles between the side branches of the bifurcation intensify flow perturbations, and highly curved segments show low ESS in the inner aspect of curvatures. Further research on the flow conditions which determine the initiation and progression of atherosclerosis in bifurcations will allow for more efficient prevention and management strategies.
冠状动脉分叉是动脉粥样硬化最常发生的部位之一。在这些区域，复杂的血液动力学条件占主导地位，局部流动干扰决定了动脉粥样硬化的定位和进展。壁切应力（ESS）是影响分叉处动脉粥样硬化分布的主要血流相关因素。斑块更常见于低 ESS 区域，如主血管的侧壁和侧支，而在分流器或嵴处则不太常见，该处的 ESS 较高。然而，嵴并非没有动脉粥样硬化，在多达三分之一的病例中受到影响，但从未孤立存在。由于斑块从侧壁向周围扩张，嵴处的病变可能在动脉粥样硬化的晚期发展。脉动流通过诱导低和振荡 ESS 来增加局部致动脉粥样硬化环境。几何形状也很重要，因为分叉处侧支之间的曲率增加和角度增大加剧了流动干扰，而高度弯曲的部分在曲率的内侧面显示出低 ESS。对决定分叉处动脉粥样硬化起始和进展的血流条件的进一步研究，将有助于制定更有效的预防和管理策略。
