Introduction

Quantitative magnetic resonance angiography and non-invasive optimal vessel analysis serve as powerful tools to collect and analyze hemodynamic data from pipeline embolization patients. At our institution, patients receive post-embolization quantitative magnetic resonance angiography within 24 h of treatment and within 6 months for follow-up to evaluate pipeline patency. Here, we aim to elucidate the long-term hemodynamic changes following pipeline embolization device placement and report two cases in which in-stent stenosis was detected.

Methods

Medical records of patients who underwent pipeline embolization device placement for an internal carotid artery aneurysm between 2017 and 2019 were reviewed. Patients who received post-procedure NOVA and follow-up NOVA were included in the study (n = 32). Location and size of aneurysm, number of pipeline embolization device deployed, and complications were collected along with the non-invasive optimal vessel analysis report (flow volume rate (ml/min), mean, systolic, and diastolic flow velocities (cm/s), and vessel diameter (mm)). Internal carotid artery vessel flow rate was measured proximal to the pipeline embolization device. Derivations of hemodynamic parameters (pulsatility index, Lindegaard ratio, and wall shear stress) were calculated.

Results

The middle cerebral artery mean and diastolic flow velocities were significantly lower on the follow-up NOVA compared to the post-procedure NOVA. Moreover, follow-up NOVA demonstrated lower middle cerebral artery wall shear stress on the side with flow diversion compared to the post-procedure NOVA. In-stent stenosis, requiring intervention, was detected in two patients on follow-up NOVA. One patient had a successful balloon angioplasty of the stented internal carotid artery that resolved her stenosis. However, the second patient developed progressive stenosis and expired despite intervention.

Conclusion

Long-term hemodynamic adaptations post-pipeline embolization device demonstrate decreased wall shear stress and decreased mean and diastolic flow velocities in the distal middle cerebral artery, which suggest decreasing velocity of blood flow with endothelialization of the device. Furthermore, follow-up NOVA is a useful tool for detecting potential flow-related complications such as in-stent stenosis.

中文翻译：

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定量磁共振血管造影和无创最佳血管分析用于识别管道栓塞术后患者的并发症和长期血流动力学变化

介绍

定量磁共振血管造影和非侵入性最佳血管分析是收集和分析管道栓塞患者血流动力学数据的强大工具。在我们的机构，患者在治疗后 24 小时内接受栓塞后定量磁共振血管造影，并在随访 6 个月内进行评估管道通畅性。在这里，我们的目的是阐明管道栓塞装置放置后的长期血流动力学变化，并报告两例检测到支架内狭窄的病例。

方法

对 2017 年至 2019 年间因颈内动脉瘤接受管道栓塞装置植入的患者的医疗记录进行了审查。接受术后 NOVA 和随访 NOVA 的患者被纳入研究 ( n  = 32)。收集动脉瘤的位置和大小、部署的管道栓塞装置的数量和并发症，以及无创最佳血管分析报告（流量（ml/min）、平均、收缩和舒张流速（cm/s）和容器直径 (mm))。在管道栓塞装置附近测量颈内动脉血管流速。计算了血流动力学参数（搏动指数、Lindegaard 比和壁剪切应力）的导数。

结果

与术后 NOVA 相比，后续 NOVA 的大脑中动脉平均血流速度和舒张期血流速度显着降低。此外，后续 NOVA 表明，与术后 NOVA 相比，血流改道一侧的大脑中动脉壁剪切应力较低。在后续 NOVA 中发现两名患者存在支架内狭窄，需要干预。一名患者成功进行了颈内动脉支架球囊血管成形术，解决了狭窄问题。然而，第二名患者出现进行性狭窄，尽管进行了干预，但还是去世了。

结论

管道栓塞装置后的长期血流动力学适应表明，远端大脑中动脉的壁剪切应力降低，平均流速和舒张流速降低，这表明随着装置的内皮化，血流速度降低。此外，后续 NOVA 是检测潜在的血流相关并发症（例如支架内狭窄）的有用工具。