Purpose

Thrombosis within an occluded coronary arterial fistula (CAF) may cause angina and myocardial infarction. This study aims to estimate how the occlusion position of CAFs with terminal aneurysm affects the risk stratification of thrombosis in the fistula in terms of hemodynamics.

Methods

Twelve CAF models were reconstructed based on patient-specific computed tomography angiogram (CTA) images. They were classified into three groups: preserved group (untreated fistula), aneurysm-reserved group (occluded at the fistula terminal: distal occlusion) and aneurysm-removed group (occluded before the aneurysm: proximal occlusion). Hemodynamics results were analyzed and compared with the clinical follow-up results.

Results

The results showed that: (1) Hemodynamic patterns within the fistula before and after treatment were significantly different among patients. (2) Aneurysm-removed occlusions showed better improvements with respect to the CAF blood-stealing phenomena. (3) Irrespective of whether aneurysms were removed or not, a disturbed flow pattern was observed. Areas having high OSI and low TAWSS were present in the post-occluded CAFs. The removal of the aneurysm, however, would alleviate the flow disturbance, and decrease the proportion of the area of OSI > 0.3. (4) The thrombosis region spotted in the follow-up patient CTAs was consistent with the computed high OSI area.

Conclusions

A proximal occlusion, namely, removing the aneurysm of the CAF, may help in reducing the risk of thrombosis after surgery. However, follow-up studies with a larger cohort should be carried out to test and verify this speculation in the future.

中文翻译：

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闭塞位置在终末动脉瘤冠状动脉瘘中的作用：血流动力学的观点。

目的

冠状动脉瘘（CAF）内的血栓形成可能导致心绞痛和心肌梗塞。这项研究旨在评估CAF闭塞位置与终末动脉瘤如何从血液动力学方面影响瘘管内血栓形成的危险分层。

方法

基于患者特定的计算机断层扫描血管造影（CTA）图像重建了十二个CAF模型。将其分为三组：保留组（未治疗的瘘管），保留动脉瘤的组（闭塞在瘘管末端：远端闭塞）和去除动脉瘤的组（闭塞在动脉瘤之前：闭塞近端）。分析血流动力学结果并将其与临床随访结果进行比较。

结果

结果表明：（1）治疗前后瘘管内的血流动力学模式明显不同。（2）相对于CAF窃血现象，去除动脉瘤的阻塞表现出更好的改善。（3）不论是否去除动脉瘤，均观察到流动模式紊乱。后阻塞CAF中存在OSI高且TAWSS低的区域。但是，去除动脉瘤将减轻血流紊乱，并降低OSI> 0.3的面积比例。（4）随访患者CTA中发现的血栓形成区域与计算出的高OSI面积一致。

结论

近端闭塞，即去除CAF的动脉瘤，可能有助于降低手术后血栓形成的风险。但是，将来应进行更大范围的随访研究，以测试和验证这种推测。