School of Medical Technology, Beijing Institute of Technology, Beijing 100081, China.
Department of Vascular Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310000, China.
Comput Methods Programs Biomed. 2024 Oct;255:108364. doi: 10.1016/j.cmpb.2024.108364. Epub 2024 Aug 5.
The isolated superior mesenteric artery dissection (ISMAD) is a rare but potentially fatal vascular disorder. Classifications for ISMAD were previously proposed based on morphometric features. However, the classification systems were not standardized and verified yet. This study conducted computational flow analysis to validate the latest classification system of ISMAD and aid clinical decision-making based on hemodynamic parameters.
62 patients with ISMAD were included and classified into different types according to false lumen structures (five types, Type I-V) and true lumen patency (two types, Type P and Type S) according to Qiu classification system. Computational fluid dynamics and three-dimensional structural analyses were conducted on the basis of computed tomography angiography datasets. Quantitative and qualitative functional analyses were performed via parameters of interest including volume flow of each minute, pressure drop, pressure gradient, the derivative parameters of wall shear stress such as time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and the relative residence time (RRT). Statistical analyses were conducted among different ISMAD types.
TAWSS, OSI and RRT showed significant difference among different types when classified using false lumen structures. In detail, Type IV showed significantly higher TAWSS than other types (p = 0.007). OSI was obviously higher in Type II (p = 0.015). Type IV also presented the lowest RRT (p = 0.005). The pressure drop, pressure gradient, OSI and RRT showed higher value in Type S than that in Type P, demonstrating a statistical significance with p values of 0.017, 0.041, 0.001 and 0.012, respectively. While Type P had larger volume flow than Type S (p = 0.041).
The notable differences in hemodynamic features among different types demonstrated the feasibility of Qiu classification system. The evaluation based on hemodynamic simulation might also provide insights into risk identification and guide therapeutic decisions for ISMAD.
孤立性肠系膜上动脉夹层（ISMAD）是一种罕见但潜在致命的血管疾病。ISMAD 的分类以前是基于形态学特征提出的。然而，这些分类系统尚未得到标准化和验证。本研究通过计算血流动力学分析来验证最新的 ISMAD 分类系统，并基于血流动力学参数辅助临床决策。
纳入 62 例 ISMAD 患者，根据 Qiu 分类系统，根据假腔结构（五型，I-V 型）和真腔通畅性（两型，P 型和 S 型）将患者分为不同类型。在计算机断层血管造影数据集的基础上进行计算流体动力学和三维结构分析。通过感兴趣参数（包括每分钟的容积流量、压降、压力梯度、壁面切应力的导数参数，如平均壁面切应力（TAWSS）、振荡剪切指数（OSI）和相对驻留时间（RRT））进行定量和定性功能分析。对不同类型的 ISMAD 进行统计学分析。
根据假腔结构进行分类时，TAWSS、OSI 和 RRT 在不同类型之间存在显著差异。具体来说，IV 型的 TAWSS 明显高于其他类型（p = 0.007）。II 型的 OSI 明显较高（p = 0.015）。IV 型的 RRT 也最低（p = 0.005）。S 型的压降、压力梯度、OSI 和 RRT 均高于 P 型，p 值分别为 0.017、0.041、0.001 和 0.012，差异具有统计学意义。而 P 型的容积流量大于 S 型（p = 0.041）。
不同类型之间血流动力学特征的显著差异证明了 Qiu 分类系统的可行性。基于血流动力学模拟的评估也可能为识别风险提供线索，并为 ISMAD 指导治疗决策。
