PMC8242161_01
Volumetric and multiplanar reconstructions of the aorta, left and right internal mammary artery (IMA) of a Marfan syndrome patient after Bentall procedure. 256-slice CT angiography of the chest was performed at three different timepoints. (A) In 2013, left and right IMA-s were intact without any signs of aneurysms. (B) In 2015, both arteries demonstrated a small dilatation (~0.5 cm) in the mid-section. (C) Follow-up scans after 3 years revealed a saccular pearl-string-like aneurysm of the right IMA with thrombus on the walls, an aneurysm of the left IMA and increase in diameter of the aortic arch. (D) Follow-up CT done in 2019 shows no progression of the aneurysms.
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F1
The patient had been followed-up regularly with echocardiography and as part of his evaluation, he had a contrast enhanced chest computed tomography (CT) scan in February 2013 (Figure 1A), which showed that the aortic arch expanded distally to the conduit. On the subsequent CT in June 2015 (Figure 1B) the intimal flap and the degree of aortic dilation did not change significantly compared to the condition in 2013. In February 2018 a control CT (Figure 1C) revealed the progression of the aortic dilatation and four sequential saccular pearl-string-like aneurysms could be observed on the right IMA (RIMA) in the level of the body of the sternum with a growing diameter of 10-19 mm. Due to the lack of guidelines on the management of IMA aneurysms, given the asymptomatic state of the patient, the increased tortuosity of the affected vessels seen on the CT scans (Figure 1) and the expected difficult anatomic situation after the prior cardiac surgery, we decided to apply a close follow-up with blood pressure control to avoid the probable complications of an intervention.
The timeline demonstrates the main episodes of patient care. The key steps of surveillance CT scans are shown, the last one was done in October 2020. The two surgeries and the emergency care were also important aspects in the patient's case.
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F2
(A) A progression of the tortuosity of the right internal mammary artery (RIMA) and the left internal mammary artery (LIMA) demonstrated by an increase in the Distance Metric (DM) value can be observed. The other parameters used to assess the tortuosity of a vessel are Inflection count metric (ICM), which is sensitive to higher amplitude structures, Sum of angles metric (SOAM), which is increased in case of higher frequency structures and ICM/SOAM. In this case, they are less conclusive as they all show a decreasing tendency. (B) The thoracic aorta shows an increasing tortuosity with increasing amplitude and frequency of the curves demonstrated by the overall rise of the ICM, SOAM, and ICM/SOAM parameters.
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F3
Parallel to the progression of the aneurysms, an increase in the DM can be observed in case of the RIMA and the LIMA, which demonstrates a progression of the tortuosity of these vessels (Figure 3A). At the same time the thoracic aorta demonstrates an overall rise in the ICM, SOAM and ICM/SOAM parameters, meaning an increasing tortuosity with increasing amplitude and frequency of the curves, dominated by the rise in amplitude as suggested by ICM/SOAM (Figure 3B).