Multidetector-row Computed Tomography in … Computed Tomography in Diagnosis of a Large Right...
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Multidetector-row Computed Tomography in
Diagnosis of a Large Right Coronary Artery
Aneurysm Resulting from Arteriovenous Fistula
Kun-Eng Lim,1 Kuei-Ton Tsai2 and Yu-Lin Ko3
Coronary artery aneurysm with arteriovenous fistula is an uncommon condition. We report a 52-year-old male with
a large right coronary artery aneurysm resulting from a coronary artery-to-right ventricle fistula. The aneurysm and
the fistula were demonstrated by an electrocardiography-gated multidetector-row computed tomography coronary
angiography. Three months after surgery, the computed tomography coronary angiography showed no fistula, and
the distal right coronary artery was bypassed with a saphenous graft. Thus, we concluded that in some instance
multidetector-row computed tomography coronary angiography may be helpful for diagnosis and demarcation of
coronary artery aneurysm with arteriovenous fistula.
Key Words: Coronary arteriovenous fistula � Computed tomography
INTRODUCTION
Coronary artery aneurysm is an uncommon disease.
Coronary artery aneurysm is defined as coronary dilata-
tion that exceeds the diameter of normal adjacent seg-
ment or the diameter of the patient’s largest coronary
vessel by 1.5-2 times.1 The incidence of this anomaly is
between 1.4% and 5%.2,3 Coronary artery aneurysm
caused by coronary arteriovenous fistula is an even more
uncommon condition.4-7 Currently, multidetector-row
computed tomography (MDCT) coronary angiography
has become a valuable method for evaluation of coro-
nary artery disease and the heart.7-9 Herein, we report
MDCT coronary angiography is helpful for demonstrat-
ing a large right coronary aneurysm resulting from a cor-
onary artery- to- right ventricle (RV) fistula.
CASE REPORT
A 52-year-old male suffered from effort-related
chest tightness and palpitation for about 2 weeks. He had
cardiac murmur and had been told he had heart disease
by her family physician a long time before. He family
history was unremarkable. He had a history of hyper-
lipidemia (at admission, triglyceride measured 211 mg/
dl) and peptic ulcer for many years. On physical exami-
nation, the patient appeared essentially well. However, a
harsh grade 2-3/6 continuous murmur was audible over
the left lower parasternal border. Chest radiography
showed widening of the right mediastinum. Electrocardi-
ography (ECG) showed left atrial enlargement and right
bundle branch block. Transthoracic 2-dimensional and
color-Doppler echocardiography showed mildly dilated
left ventricle and aortic root, thick interventricular sep-
tum, mild mitral and tricuspid regurgitations, and moder-
ate aortic regurgitation. Furthermore, there was a large
right coronary artery (RCA) orifice due to a suspected
coronary arterio-venous fistula. Transesophageal echo-
47 Acta Cardiol Sin 2008;24:47�50
CT Showed a Right Coronary Aneurysm with Arteriovenous FistulaCase Reports Acta Cardiol Sin 2008;24:47�50
Received: July 21, 2007 Accepted: September 17, 20071Departments of Radiology, 2Cardiovascular Surgery, 3Cardiology,
Buddist Tzu Chi General Hospital, Xindian City, Taipei County,
Taiwan.
Address correspondence and reprint requests to: Dr. Kun-Eng Lim,
Department of Radiology, Buddist Tzu Chi General Hospital, 289,
Jiauguo Road, Xindian City, Taipei County, Taiwan, R.O.C. Tel: 886-
2-6628-9779 ext. 1100; Fax: 886-2-2546-1665; E-mail: kevinblueski
@yahoo.com.tw
cardiography showed a dilated aortic root and a large
RCA from the right coronary sinus along the RV free
wall. In addition, the large RCA also compressed the RV
inflow tract and drained into the RV near the tricuspid
valve level. Yet, the left ventricular systolic function was
preserved. Invasive coronary angiography demonstrated
a large RCA aneurysm about 3.3 cm in diameter origi-
nating from the ostium of the RCA, with the draining
site of arteriovenous fistula not being able to be identi-
fied. The left main coronary trunk and its tributaries
were patent, and left ventricular ejection was about 66%.
For further evaluation of any additional findings as pre-
operative work-up, an ECG-gated enhanced MDCT was
acquired with a 64-slice scanner (Light Speed VCT,
General Electric, Milwaukee, Wisconsin). Contrast agent
transit time was determined using a 20-ml bolus injec-
tion of contrast agent (Ultravist 370 mg/dl, Schering,
Berlin, Germany), followed by a 40-ml saline chaser.
For acquisition of the volume data set, the patient re-
ceived a total of 65 ml contrast agent via antecubital vein
at a rate of 5 ml/s, followed by a 40-ml saline chaser.
The scan parameters were: 64 � 0.625-mm collimation,
caudocranial scan direction, 350-ms rotation time,
120-kV tube voltage, and 600-mA tube current. Images
were reconstructed with ECG gating to obtain optimal
motion-free image quality. All reconstructed images
were transferred to dedicated workstation for postpro-
cessing and evaluation (Advantage 4.2, General Electric,
Milwaukee, Wisconsin). Volume-rendered images of
MDCT coronary angiography showed a large RCA aneu-
rysm, without any luminal stenosis (Figures 1A and 1B).
There was no evidence of wall calcification of the RCA
aneurysm. The distal portion of RCA aneurysm draining
directly into the posterior wall of the RV was demon-
strated on thick-slab maximum intensity projection
image (Figure 2).
The patient underwent surgical intervention with
closure of the fistula using a hemashield patch; the RCA
aneurysm was excluded from the right coronary circula-
tion to avoid late rupture and thromboembolism compli-
cation by closure of both the proximal and distal ends of
this lesion. Direct aneurysmorrhaphy was done, and the
distal RCA was bypassed with a saphenous vein graft.
Post operation recovery was uneventful, and the patient
was discharged from hospital 18 days after operation.
Post-operative echocardiography revealed thickened
posterior left ventricular wall, abnormal septal wall mo-
tion, adequate left ventricle and RV systolic function,
and dilated aortic root with mild to moderate aortic re-
gurgitation. Three months after surgery, the computed
tomography coronary angiography showed no fistula,
and the distal right coronary was bypassed with a patent
saphenous graft (Figure 3).
Acta Cardiol Sin 2008;24:47�50 48
Kun-Eng Lim et al.
(A)
(B)
Figure 1. Three-dimensional volume-rendered images of computed
tomography coronary angiography showed a large right coronary
artery aneurysm and its distal portion directed to the right ventricle. Ao,
RA, RCA, LV, RV, LAD, and LCX indicate aorta, right atrium, right
coronary artery, left ventricle, right ventricle, left anterior descending
coronary artery, and left circumflex artery, respectively.
DISCUSSION
Coronary artery aneurysm is a rare coronary artery
disease in adult patients.1-3 It may be a congenital
anomaly, or secondary to other diseases, such as athe-
rosclerosis, post coronary intervention, infection, Ka-
wasaki’s disease, trauma, systemic degenerative dis-
ease, or other inflammatory diseases.1,2,10,11 In our pa-
tient, no aforementioned causes were found, so we
thought this patient might suffer from a congenital fis-
tula. The majority of fistulae terminate in the right
side of the heart. The most frequent sites of termina-
tion, in descending order, are the RV, right atrium, cor-
onary sinus, pulmonary trunk, left ventricle, and supe-
rior vena cava.
Coronary angiography, currently the reference stan-
dard for imaging of coronary artery disease and anat-
omy, is an invasive procedure that requires highly trained
personnel, with significant cost and low, but not negligi-
ble, procedure-related morbidity and mortality.12 In addi-
tion, there is a radiation dose to the operator. Owing to
the complex three-dimensional nature of coronary artery
fistula combined with a large coronary artery aneurysm,
invasive angiography usually cannot fully delineate the
complete outline of the large coronary artery aneurysm,
side branches, and the fistula, as in our case.
Magnetic resonance (MR) imaging is a suitable
non-invasive imaging tool for evaluation of coronary ar-
tery anomalies and their courses, yet it requires longer
time, is more expensive, and is limited with regard to de-
termination of the distal coronary arterial course.13 Also,
the spatial resolution achieved with this imaging is mar-
ginal for coronary artery imaging. MR imaging is used
for evaluation of coronary artery anomalies only when
the patient has contraindication for CT because of a se-
vere allergic reaction to iodinated contrast agent or due
to impaired renal function (creatinine level of > 1.5
mg/dl).
MDCT coronary angiography is a faster, safer, more
convenient, and non-invasive diagnostic modality to de-
tect the presence of coronary artery anomalies.9,14 In this
case, the entire examination was completed within 5
minutes and was performed as an outpatient procedure.
MDCT combines the advantages of coronary angio-
graphy and intravascular ultrasound in one noninvasive
modality, which allows full demonstration of the course
of the coronary artery aneurysm, side branches, and
other important information like diameter, lumen, and
wall of the coronary artery, any presence or absence of
calcification, and the myocardium.6,9 In addition, MDCT
also can identify other significant non-cardiac findings
during the same examination. All these data are crucial
49 Acta Cardiol Sin 2008;24:47�50
CT Showed a Right Coronary Aneurysm with Arteriovenous Fistula
Figure 2. Axial thin-slab maximal intensity projection reconstructed
image showed a large right coronary aneurysm (long arrow) with its
distal portions draining into the RV. A, F, and RV indicate aneurysm,
fistula, and right ventricle, respectively.
Figure 3. Three months after surgery, follow-up computed tomography
coronary angiography with volume-rendered technique showed no more
fistula, and the distal right coronary was bypassed with a patent
saphenous vein graft.
in planning possible surgical or therapeutic interven-
tions. In this case, the morphological findings of fistula
and the RCA aneurysm were adequately provided by
MDCT. Although MDCT has many aforementioned ad-
vantages when assessing coronary artery anomalies, ra-
diation exposures are relatively high in using this tech-
nique, ranging from 5-18 mSV, as compare with those
for invasive coronary angiography (5-7 mSv).15,16 There-
fore, appropriate use of this technique is needed, espe-
cially for pediatric patients.
In contrast transesophageal echocardiography is a
practical and diagnostic test for assessing the coronary
artery anomalies, yet it is not totally non-invasive, is
operator-dependent, and may fail to completely delin-
eate the complex anatomy of the coronary anomalies.
Furthermore, this test requires full cooperation of the
patient. As MDCT is a fast, accurate, and non-invasive
technique that can delineate the complex coronary ano-
malies and extracardiac findings, we advocate that
MDCT may be very helpful in some instance for inves-
tigating the adult patients suspected of having coronary
anomalies.
In summary, we have reported a large coronary ar-
tery aneurysm resulting from coronary artery fistula to
the RV, which was demonstrated by MDCT coronary
angiography. When patient refuses coronary angio-
graphy or for whatever reasons coronary angiography
cannot be performed, MDCT angiography may serve as
an alternative diagnostic tool for assessing coronary ar-
tery anomalies.
REFERENCES
1. Syed M, Lesch M. Coronary artery aneurysm: a review. Prog
Cardiovascular Dis 1997;40:77-84.
2. Daoud AS, Pankin D, Tulgan H, Florentin RA. Aneurysms of the
coronary artery: report of ten cases and review of literature. Am J
Cardiol 1963;11:228-37.
3. Gottesfeld S, Makaryus AN, Singh B. Thrombosed right coronary
aneurysm presenting as a myocardial mass. J Am Soc Echocar-
diogr. 2004;17:1319-22.
4. Nakamura Y, Yutani C, Imakita M, Ischibaschi-Ueda H, Nishida
N, Iida K, Hisaki R, Isobe F. A huge coronary aneurysm resulting
from a coronary artery-to-left ventricle fistula. Intern Med
1998;37:366-9.
5. Hobbs RF, Millir HD, Raghavan PV, Moodie DS, Sheldon WC.
Coronary artery fistulae: a 10-year review. Cleve Clin Q 1982:49:
191.
6. Funabaschi N, Asano M, Komuro Issei. Right coronary artery an-
eurysm with fistula to left ventricle. J Thorac Imaging 2006;
21:63-5.
7. Herzog C, Zangos S, Zwerner P, et al. CT of coronary artery dis-
ease. J Thorac Imaging 2007;22:40-8.
8. Hoffmann MH, Lessick J. Multidetector-row computed tomogra-
phy for noninvasive coronary imaging. Expert Rev Cardiovasc
Ther 2006;4:583-94.
9. Manghat NE, Morgan-Hughes GJ, Marshall AJ, et al. Multi-
detector row computed tomography: imaging congenital coronary
artery anomalies in adults. Heart 2005;91:1515-22.
10. Doi YL, Hamashige N, Odawara H, Kuzume O, Chikamori T,
Ozawa T. Ring calcification of coronary aneurysms in an adoles-
cent. Chest 1987;92:1118.
11. Di Mario C, Zanchetta M, Maiolino P. Coronary aneurysms in a
case of Ehlers-Danlos syndrome. Jpn Heart J 1988;29:491.
12. Smith SCJ, Dave JT, Jacobs AK, et al. ACC/AHA guidelines for
percutaneous coronary intervention (revision of the 1993 PTCA
guidelines) executive summary: a report of the American College
of Cardiology/American Heart Association task force on practical
guidelines endorsed by the Society for Cardiac Angiography and
Interventions. Circulation 2001;103:2051-4.
13. Dewey M, Teige F, Schnapauff D, et al. Noninvasive detection of
coronary artery stenoses with multislice computed tomography or
magnetic resonance imaging. Ann Intern Med 2006;145:466-7.
14. Raff GL, Gallagher MJ, O’Neill WW, et at. Diagnostic accuracy
of noninvasive coronary angiography using 64-slice spiral com-
puted tomography. J Am Coll Cardiol 2005;46:552-7.
15. Marin RL, Gerber TC, Macollough CH. Radiation dose in com-
puted tomography of the heart. Circulation 2003;107:917-22.
16. Cheng YV, Lepor NE, Madyoon H, et al. Presence and severity of
noncalcified coronary plaque on 64-slice computed tomography
coronary angiography in patients with zero and low coronary ar-
tery calcium. Am J Cardiol 2007;99:1183-6.
Acta Cardiol Sin 2008;24:47�50 50
Kun-Eng Lim et al.