Key Words
Ascending aorta - Saccular aneurysm - Multimodality imaging
Introduction
A 26-yr-old male presented with exertional dyspnea for six months. There was no history
of chest trauma or angina, chronic fever, night sweats, generalized muscle aches,
malaise, or rash. There was no history of intravenous drug abuse or unprotected sexual
intercourse. There was no family history of aortic diseases. Clinical examination
revealed an early diastolic murmur without any marfanoid habitus. A prominent right
upper cardiac border was seen on the X-ray, suggesting a dilated ascending aorta ([Fig. 1]). On transthoracic echocardiography, a mildly dilated left ventricle with moderate
aortic regurgitation was noted; in addition, a large saccular structure, compressing
the left atrium (LA), was visualized ([Fig. 1]). Transesophageal echocardiography delineated a defect in the ascending aorta, with
a flap-like opening (3.5 × 4.5 mm) just above the sino-tubular junction, communicating
with a huge sac-like aneurysm ([Fig. 1]). A 64-slice multidetector cardiac computerized tomography (MDCT) apparatus with
virtual intra-aortic endoscopic reconstruction confirmed a large (59 × 66 mm) saccular
ascending aortic aneurysm, extending into the middle mediastinum ([Fig. 1D–1G]). While no dissection flap was visible, a defect in the ascending aorta communicating
with the aneurysm was clearly demonstrable.
Figure 1. A. Chest X-ray showing prominent mid and upper right cardiac border suggestive of
a dilated ascending aorta. B. Transthoracic echocardiography revealed a large saccular
mass (S) arising close to the ascending aorta and compressing the LA to almost a sliver.
C. Transesophageal echocardiography (marked arrow) delineated a rent in the ascending
aorta just above the sino-tubular junction. The saccular mass was connected with the
ascending aorta via a flap-like communication with demonstrable color flow across
it. D and E. A 64-slice multidetector cardiac CT imaging confirmed the presence of
the saccular mass (S) arising from the ascending aorta. F and G. Intra-aortic virtual
endosocpic reconstruction of the multidetector CT images clearly outlined the rent
in the proximal portion of ascending aorta, above the sino-tubular junction, leading
into the large sac like aneurysm.
Use of the 64-slice MDCT demonstrated the dimensions of saccular aneurysm along with
the presence and size of communication between aorta and aneurysm and their relationship
with surrounding structures, including the compressive effects on the LA and aorta.
Importantly, it CT also delineated that no dissection flap or false lumen was visible.
In view of the absence of any obvious trauma or dissection, these findings suggested
that possible chronic insidious degeneration with weakening of the aortic media and
resultant rupture caused this pseudoaneurysm.
The patient underwent urgent surgery with repair of the ascending aorta after excision
of the saccular aneurysm and placement of a Dacron graft. Aortic valve was tricuspid
and mildly thickened and replaced with a size 22 SJM bileaflet mechanical prosthesis.
The aortic tissue at the site of defect was grayish white in appearance and histopathologic
examination revealed degenerative changes in the form of myxoid changes with fibrinoid
necrosis and mixed inflammatory infiltrates ([Fig. 2]).
Figure 2. A. Histopathologic examination revealed degenerative changes in the form of myxoid
changes with fibrinoid necrosis and (B) mixed inflammatory infiltrates.
