背景:形态学上,主动脉瘤破裂的风险主要根据其类型进行评估(例如,梭形或囊状)和直径。基于有限元分析,近年来,峰值壁应力已被确定为更敏感,更具体的预测破裂。此外,在有限分析中,动脉瘤的颈部是壁应力的最高峰值,并与破裂点有关。
方法:一名74岁有红细胞增多症病史的男性患者在术前检查慢性脓胸时偶然发现了一个囊状主动脉瘤(84mm)。使用开放式支架进行主动脉弓移植物置换。
结论:形态学,这种情况与破裂的风险很高有关;尽管如此,它没有破裂。在这种情况下,动脉瘤颈部有一个壁血栓(可能是由于红细胞增多症形成的),该血栓正在经历最高的壁应力峰值,并与破裂点相关.即使对于巨大的囊状动脉瘤,壁血栓也可以降低壁应力峰值,并可以降低破裂的风险。此外,动脉瘤中的壁血栓被完全占据,例如在线圈栓塞期间。因此,红细胞增多症可以降低巨大囊状动脉瘤破裂的风险。
BACKGROUND: Morphologically, the risk of aortic aneurysm rupture is mainly evaluated based on its type (e.g., fusiform or saccular) and diameter. Based on the finite element analysis, peak wall stress has been identified as a more sensitive and specific predictor of rupture in recent years. Moreover, in finite analysis, the neck of aneurysm is the highest peak wall stress and is associated with the rupture point.
METHODS: A saccular aortic aneurysm (84 mm) was incidentally detected during preoperative examination for chronic empyema in a 74-year-old male patient with a history of polycythemia. Aortic arch graft replacement using an open stent was performed.
CONCLUSIONS: Morphologically, this case was associated with a very high risk of rupture; nevertheless, it did not rupture. In this case, a mural thrombus (likely formed due to polycythemia) covered the neck of aneurysm that is experiencing the highest peak wall stress and is associated with the rupture point. The mural thrombus decreased peak wall stress and could reduce the risk of rupture even for huge saccular aneurysms. Furthermore, the mural thrombus was fully occupied in aneurysms, such as during coil embolization. Thus, polycythemia could decrease the risk of rupture of huge saccular aneurysms.