Keywords
intramural hematoma - aortic dissection - intimal tear
A 78-year-old woman, hypertensive, was admitted to our hospital for acute chest pain.
An unenhanced computed tomography (CT) scan was performed, which showed an aneurysm
of the thoracic aorta (6 cm) complicated by Type A intramural hematoma (IMH) ([Fig. 1A], [B]). After contrast medium administration, a localized blood-filled pouch protruding
from the true lumen into the thrombosed false lumen of the aorta was also detected
in the ascending aorta, 1 cm before the origin of brachiocephalic artery ([Fig. 1C]–[E]; [Video 1]), configuring a so-called ulcer-like projection. The patient was referred for surgery.
During hypothermic circulatory arrest, the hematoma ([Fig. 2A]) was evacuated. A linear-shaped intimal tear, measuring 1.5 cm, was identified 1
cm before the origin of brachiocephalic artery ([Fig. 2B]). A hemiarch procedure associated to root replacement with a biological valved conduit
using two-graft technique was performed ([Fig. 2C]). The postoperative course was uneventful, and the patient was discharged home on
the 13th postoperative day.
Fig. 1 (A) Axial and (B) sagittal unenhanced CT images show a crescent-shaped thickening of the aortic wall
(arrowheads) with greater attenuation than the lumen, characteristic for intramural
hematoma (IMH). (C) Axial and (D) sagittal contrast-enhanced CT images show a localized blood-filled pouch (arrows)
protruding into the IMH from the aortic lumen through an intimal lesion, characteristic
for ulcer-like projection (ULP). (E) Volume rendering reconstruction showing ULP in the anterior wall of the ascending
aorta.
Fig. 2 (A) Intraoperative view of the IMH (arrowhead). (B) Intraoperative findings of 1.5 cm linear-shaped intimal tear (arrow). (C) Hemiarch + biological valved conduit repair procedure; arrows show distal and graft-to-graft
anastomosis.
Video 1
Axial computed tomography animation showing Type A intramural hematoma (IMH) and ulcer-like
projection (ULP) of the ascending aorta.
Since the first description, IMH was reported as a clinical entity defined as “dissection
without intimal tear due to rhexis of vasa vasorum,” but this theory has not been
scientifically validated. Some authors believe that all IMH cases are acute dissections
with thrombosis of the false lumen and that an intimal tear is always present, but
it cannot be identified; thus, IMH could not exist.[1] The newest improvements in noninvasive diagnostic imaging techniques, particularly
multidetector CT, have recently permitted to identify lesions that could be considered
as intimal tears.[2]
[3] The CT finding of an intimal lesion in the case, we present herein is intraoperatively
validated, is in agreement with the aforementioned hypothesis, suggesting that IMH
may represent a part of a disease (acute aortic dissection) and not a disease apart.
