Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Department of Mechanical Engineering, Texas A&M University, College Station, TX, USA.
J Int Med Res. 2020 Nov;48(11):300060520968449. doi: 10.1177/0300060520968449.
To investigate the relationship between the characteristics of intraluminal thrombus (ILT) with abdominal aortic aneurysm (AAA) expansion.
This retrospective clinical study applied homogeneous multistate continuous-time Markov chain models to longitudinal computed tomography (CT) data from Korean patients with AAA. Four AAA states were considered (early, mild, severe, fatal) and the maximal thickness of the ILT (max), the fraction of the wall area covered by the ILT (area) and the fraction of ILT volume (vol) were used as covariates.
The analysis reviewed longitudinal CT images from 26 patients. Based on likelihood-ratio statistics, the area was the most significant biomarker and max was the second most significant. In addition, within AAAs that developed an ILT layer, the analysis found that the AAA expands relatively quickly during the early stage but the rate of expansion reduces once the AAA has reached a larger size.
The results recommend surgical intervention when a patient has an area more than 60%. Although this recommendation should be considered with caution given the limited sample size, physicians can use the proposed model as a tool to find such recommendations with their own data.
探讨腹主动脉瘤（AAA）扩张过程中瘤腔内血栓（ILT）特征与AAA 扩张之间的关系。
本回顾性临床研究采用同质多状态连续时间马尔可夫链模型对韩国 AAA 患者的纵向 CT 数据进行分析。考虑了 4 种 AAA 状态（早期、轻度、重度、致命），并将 ILT 的最大厚度（max）、ILT 覆盖的管壁面积分数（area）和 ILT 体积分数（vol）作为协变量。
该分析共回顾了 26 例患者的纵向 CT 图像。基于似然比统计，area 是最显著的生物标志物，max 是第二显著的生物标志物。此外，在形成 ILT 层的 AAA 中，分析发现，AAA 在早期阶段扩张速度相对较快，但一旦 AAA 达到较大尺寸，扩张速度就会降低。
当患者的 area 超过 60%时，建议进行手术干预。虽然考虑到样本量有限，该建议应谨慎使用，但医生可以使用所提出的模型作为工具，根据自己的数据找到此类建议。
