A 57-year-old man was diagnosed with Stanford type A acute aortic
dissection (AAD) by computed tomography (CT) (Figure 1). Although he had
no fever and no symptoms of pneumonia, remarkable infiltration shadows
around the right hilum mimicking coronavirus-associated pneumonia were
observed on the lung window setting CT (Figure 2). Since novel
coronavirus infection (Covid-19) was just expanding, the possibility of
coronavirus pneumonia could not be ruled out. After careful
consideration of the surgical indication, lifesaving was prioritized,
and an urgent total arch replacement was eventually performed.
Intraoperative findings showed that large subadventitial hematomas had
spread from the dorsal aspect of the ascending aorta to the right
pulmonary artery (PA). The infiltration shadows of the lung were
considered to be subadventitial hematomas that spread along the right PA
into the right lung. Polymerase chain reaction examination for
coronavirus was negative.
Because the ascending aorta and the main PA trunk share the adventitia,
hematomas may spread along the PA when the ascending aorta penetrates.
In very rare cases, the hematomas may extend beyond the hilum to the
lung1, and more rarely, penetrated hematomas may cause
obstruction of the right PA2. Regardless of whether
the hematomas stay around the main PA or spread toward the hilum, large
hematomas are usually observed behind the ascending aorta in such cases.
In our case, it was difficult to preoperatively confirm whether the
infiltration shadows were related to AAD because only a few hematomas
were observed around the ascending aorta. If CT findings similar to
those shown here are found in AAD, the possibility of subadventitial
hematomas spreading along the PA should be considered.
Reference
- Sueyoshi E, Sakamoto I, Uetani M, Matsuoka Y, Suenaga E. CT
findings of ruptured intramural hematoma of the aorta extending along
the pulmonary artery. Cardiovasc Intervent Radiol 2007;30:321-323.
- Sheu JJ, Fu M, Lee FY, Ng SH, Wan YL, Ko SF. Ascending aortic
dissecting aneurysm with isolated right pulmonary arterial medial
intramural hematoma. Ann Thorac Surg 2008;85:2127-2128.
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