Supplementary Material for: Persistence of Intraluminal Thrombus Makes Saccular Aneurysm More Biologically Active than Fusiform in an Experimental Rat Model

Introduction: Saccular aneurysms are thought to have a worse prognosis than fusiform aneurysms in humans, due to hemodynamic reasons. However, data comparing hemodynamic and biology in saccular and fusiform aneurysms are lacking. The main objective was to evaluate the impact of aneurysm morphology on intra-luminal thrombus (ILT) formation and activity. Methods: Forty Lewis rats were ran­domly divided into 2 groups of 20: “saccular” (Group A) and “fusiform” (Group B) aneurysms. Decellularized thoracic aortas from guinea pigs were xenografted to create saccular or fusiform aneurysms. Final imaging evaluation of the aneurysms was carried out during the third week, by quantitative Doppler ultrasound and magnetic resonance imaging. Assays of myeloperoxidase (MPO), platelet factor 4 (PF4), advanced oxidation protein products (AOPPs) iron and matrix metallopeptidase-9 (MMP-9) were performed as biological criteria. Results: Quantitatively, saccular aneurysms are characterized by a more thicker ILT, lower inflow velocities and more important relative backflow velocities as compared to fusiform aneurysms. Compared to fusiform, saccular aneurysms released significantly more MPO (p = 0.004), PF4 (p = 0.02), AOPPs (p p p Conclusion: Experimental saccular and fusiform aneurysms show differential specific hemodynamics, which seem to impact the histology and the biology of the ILT in each type of aneurysm.

引言：学界普遍认为，人类囊状动脉瘤（saccular aneurysms）的预后较梭形动脉瘤（fusiform aneurysms）更差，其机制与血流动力学（hemodynamic）因素相关。然而，目前尚无针对囊状与梭形动脉瘤血流动力学及生物学特性的对比研究数据。本研究的核心目的为评估动脉瘤形态对管腔内血栓（intra-luminal thrombus, ILT）形成与活性的影响。
方法：将40只Lewis大鼠随机分为两组，每组20只，分别构建囊状动脉瘤模型（A组）与梭形动脉瘤模型（B组）。采用脱细胞豚鼠胸主动脉进行异种移植，以制备囊状或梭形动脉瘤模型。于造模后第3周，通过定量多普勒超声与磁共振成像对动脉瘤完成最终影像学评估。同时以髓过氧化物酶（myeloperoxidase, MPO）、血小板因子4（platelet factor 4, PF4）、晚期氧化蛋白产物（advanced oxidation protein products, AOPPs）、铁离子及基质金属蛋白酶-9（matrix metallopeptidase-9, MMP-9）作为生物学检测指标开展相关实验。
结果：定量分析结果显示，相较于梭形动脉瘤，囊状动脉瘤的管腔内血栓更厚，流入流速更低，相对反流流速更高。与梭形动脉瘤组相比，囊状动脉瘤组的MPO（p=0.004）、PF4（p=0.02）及AOPPs（p p p）水平均显著升高。
结论：实验性囊状与梭形动脉瘤存在特异性的血流动力学差异，该差异似乎可影响不同类型动脉瘤管腔内血栓的组织学与生物学特性。