Pediatric Coronary Arteriovenous Fistula
CORONARY ARTERIOVENOUS FISTULA IN PEDIATRIC
PATIENTS: A 17-YEAR INSTITUTIONAL EXPERIENCE
Nan-Koong Wang, Li-Yin Hsieh, Ching-Tsuen Shen, and Yung-Ming Lin1
Background and Purpose: Coronary arteriovenous fistula (CAVF) is a rare congenital
anomaly in pediatric patients. Its clinical manifestations vary considerably and its
long-term outcome is not fully understood. This study sought to determine the natural
history and long-term outcome in CAVF patients treated over a 17-year period at
Cathay General Hospital in Taipei.
Materials and methods: The medical records of all 10 pediatric patients (five boys
and five girls aged between 15 days and 15 years) with CAVF treated from 1983
through 2000 at our hospital were reviewed. Data collected included symptoms and
signs, the findings of electrocardiography, echocardiography, catheterization, and
angiography, and surgical results.
Results: CAVF was diagnosed on the basis of color Doppler echocardiography in eight
patients and by cardiac catheterization and angiography in two. Congestive heart
failure was found in four patients and both myocardial ischemia and infarction were
found in two patients. Most of the affected coronary arteries were tortuous and dilated
with a mean diameter of 12.6 mm (range 5–40 mm). Under cardiopulmonary bypass,
fistulous terminations were sutured in seven patients, three of whom were found
to have multiple fistulous openings. Postoperative follow-up examinations revealed
that all of the affected coronary arteries and fistulas remained dilated and tortuous,
except in one patient. Two patients who had distal CAVF developed coronary
thrombus, calcification, and ventricular aneurysm at 2 and 10 years after operation,
respectively. Another patient developed fistulous recanalization 7 years after
operation, but this abnormal channel had disappeared again 3 years after
recanalization. One patient developed an iatrogenic CAVF 8 years after surgical repair
of tetralogy of Fallot.
Conclusions: Unlike adults, pediatric patients with CAVF tend to be symptomatic.
Ligation of the fistulous termination alone does not reduce the size of the fistula.
Our findings indicate that long-term follow-up is essential due to the possibility of
postoperative recanalization, persistent dilation of the coronary artery and ostium,
thrombus formation, calcification, and myocardial infarction. In addition, postoperative antiplatelet therapy is recommended, especially in patients with distal CAVF
and abnormally dilated coronary arteries.
Coronary arteriovenous fistula (CAVF) is a rare congenital anomaly that occurs mostly in the pediatric age
group [1]. Clinical manifestations vary and mainly
depend on the amount of arteriovenous shunt, thromboembolism of the fistulous coronary artery, and severity of myocardial ischemia and/or injury [2, 3]. The
natural course of the disease is extremely variable [1–
5]. Some fistulas disappear spontaneously, some
(J Formos Med Assoc
2002;101:177–82)
Key words:
coronary arteriovenous fistula
antiplatelet therapy
recanalize after surgery, and some develop thrombosis
and calcification, resulting in myocardial infarction.
However, detailed long-term follow-up data on the
natural course and outcome of CAVF are limited. The
purpose of this study was to delineate the natural
history and long-term outcome of CAVF. Special attention was given to the size of the coronary arteries and
coronary ostia, the possibility of size reduction of the
Departments of Pediatrics and 1Cardiac Surgery, Cathay General Hospital, Taipei.
Received: 13 April 2001.
Revised: 25 May 2001.
Accepted: 6 November 2001.
Reprint requests and correspondence to: Dr. Nan-Koong Wang, Pediatric Department, Cathay General Hospital, 280 JenAi Road, Section 4, Taipei, Taiwan.
J Formos Med Assoc 2002 • Vol 101 • No 3
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N.K. Wang, L.Y. Hsieh, C.T. Shen, et al
affected coronary arteries, and the regression of fistulas postoperatively. The importance of long-term
antiplatelet therapy in some patients who had dilated
coronary arteries and coronary ostia was also examined.
Materials and Methods
The charts of 10 pediatric patients (five boys and five
girls aged from 15 days to 15 years) with CAVF treated
during the period from 1983 through 2000 were reviewed for data on clinical symptoms and signs, the
findings of electrocardiography, echocardiography,
cardiac catheterization, and angiography, and surgical
results.
Clinical symptoms and signs of congestive heart failure
and myocardial ischemia or infarction were examined
and the results were correlated with laboratory data
including cardiac enzymes, catheterization data, and
angiographic findings.
The diameter of each affected coronary artery,
coronary ostium, and fistula was measured using angiography or echocardiography both pre- and
postoperatively. The possibility of normalization of the
affected coronary arteries both in size and shape and
regression of fistulas was carefully evaluated.
Results
Four of the 10 patients had congestive heart failure,
which manifested as poor weight gain, tachypnea,
cardiomegaly, and hepatomegaly. In comparison to
those who did not have congestive heart failure, these
patients were younger (Table 1). Six patients had
continuous murmurs and four had systolic murmurs.
Two patients developed myocardial ischemia and
infarction.
The diagnosis in two of our patients treated before
1984 was made by cardiac catheterization and angiography because a color Doppler machine was not
available. In the remaining eight patients treated after
1984, the diagnosis of CAVF was made using color
Doppler echocardiography and confirmed using cardiac catheterization and angiography.
Cardiac catheterization and angiography were performed in each patient to identify fistulous connections (Table 1). Based on the angiographic findings,
two types of CAVF were identified, proximal and distal
(Fig. 1), corresponding to those described by Sakakibara
et al [6]. In eight of the 10 patients, the fistulas originated proximally from the affected coronary arteries.
178
The proximal segment of the affected coronary artery,
spanning from the coronary ostium to the origin of the
fistula, was dilated. The distal lumen and branches
were normal. The remaining two patients had distal or
"end arterial" fistulas. Their coronary arteries were
dilated over the entire course and finally terminated in
fistulas within the venous side of the heart.
In nine of the 10 patients, the affected coronary
arteries and fistulas were dilated and tortuous with a
mean diameter of 12.6 mm (range, 5–40 mm). The
remaining patient (Case 10) had a network plexus-like
fistula. The affected coronary ostia were also dilated in
eight of the 10 patients, with a mean diameter of 8 mm
(range, 4–14 mm). Left ventricular aneurysm was found
preoperatively in one patient (Case 6) who had neither
an obvious history of chest pain nor congestive heart
failure.
Eight patients underwent surgery, seven of whom
underwent intracardiac direct suture of the fistulous
terminations (Table 2). Only one patient underwent
external ligation of the fistula without cardiopulmonary bypass. All patients who underwent surgery survived the procedure without complications. Three of
the seven patients who underwent intracardiac repair
had multiple fistulous terminations inside the heart.
Of the two patients who did not undergo surgery, one
(Case 7) developed an iatrogenic CAVF 8 years after a
ventriculotomy for tetralogy of Fallot. His preoperative
angiogram revealed that both the right and left coronary arteries originated from the left sinus. The right
coronary artery straddled across the anterior wall of the
right ventricular outflow tract (RVOT). To avoid injury
to the right coronary artery, a modified ventriculotomy
was performed. However, a branch of the left anterior
descending coronary artery (LAD) was wounded during the operation and developed a fistula that drained
into the RVOT (Fig. 2). The amount of fistulous shunt
was small and therefore no intervention was taken. The
other patient (Case 10) also did not undergo surgery
because the fistula was of a fine plexus form and there
were no clinical symptoms.
In order to prevent coronary thrombosis, low-dose
aspirin and dipyridamole were prescribed for two
patients (Cases 6 and 9) due to markedly dilated and
tortuous coronary arteries.
Eight patients were followed up for a duration
ranging from 5 months to 14.6 years (mean, 5 yr 4 mo)
after operation. All patients underwent color Doppler
echocardiographic examination regularly and four
underwent a second catheterization and angiography.
All of the affected coronary arteries were still abnormally dilated and tortuous except in one patient (Case
5). Seven years and 5 months after the operation, the
dilated left main coronary artery of this patient was
found to be of normal size and shape.
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8 y 4 m/M
15 d/M
6 y/F
10 d/M
10 d/F
5 y 8 m/F
15 y/M
9 m/F
1 y 3 m/M
7 y 3 m/F
1
2
3
4
5
6
7
8
9
10
Gr.
Gr.
Gr.
Gr.
Gr.
Gr.
Gr.
Gr.
Gr.
Gr.
3/6 continuous
3/6 continuous
3/6 continuous
2/6 systolic
4/6 continuous
4/6 continuous
3/6 systolic
3/6 continuous
3/6 systolic
2/6 systolic
Murmur
no
yes
no
yes
yes
no
no
yes
no
no
no
no
no
no
yes
yes
no
no
no
no
CHF MI
LM
RCA
LM
LM
LM
LAD
LAD
LAD
RCA
RCA & LAD
Origin
RA
RA
RA
RA
RA
RV apex
RVOT
RV apex
RVOT
MPA
Termination
Fistula
proximal
proximal
proximal
proximal
proximal
distal
proximal
distal
proximal
proximal
Type
1.6
n.a.
1.7
3.3
2.4
1.5
1
1.6
1.4
n.a.
0.2
n.a.
0.3
0.7
0.5
0.3
0.2
0.2
0.2
n.a.
Qp/Qs Pp/Ps
14
1.5
5
13
6
22
9
6
diameter (mm)
Max. fistula
LM, 13
RCA, 6
LM, 14
LM, 5
LM, 6
LAD, 40
LAD, 5
LAD, 9
RCA, 14
LAD, 2.5
artery (mm)
Aff. coronary
9
6
14
5
6
14
4
6
14
1.5
ostium (mm)
Aff. coronary
Intracardiac repair
External ligation
Intracardiac repair
Intracardiac repair
Intracardiac repair
Intracardiac repair
None
Intracardiac repair
Intracardiac repair
None
1
2
3
4
5
6
7
8
9
10
n.a.
n.a.
1
2
1
n.a.
1
2
2
1
No. of fistula
terminations
Lost
1y9m
3y7m
14 y 8 m
5m
2y
Lost
2y
7y5m
12 y
Follow-up period
LM still dilated
RCA still dilated
Lost to follow-up
LM still dilated. Fistula became smaller with irregular shape. A tiny residual shunt present
No more dilation of LM
LAD aneurysm, thrombus, calcification, coronary to aorta regurgitation, ventricular aneurysm
and mitral regurgitation developed
An iatrogenic fistula found 8 years 5 months after TOF Op
Proximal LAD still dilated, mid and distal thrombosed, ventricular aneurysm developed
RCA still dilated. Fistula recanalized 7 years after operation and then closed again 3 years later
spontaneously
Lost to follow-up
Follow-up result & remark
m = months; LM = left main coronary artery; n.a. = not available; y = years; RCA = right coronary artery; LAD = left anterior descending coronary artery; TOF Op = operation for tetralogy
of Fallot.
Operation
Patient
Table 2. Operations and follow-up results
CHF = congestive heart failure; MI = myocardial infarction; Qp/Qs = pulmonary blood flow / systemic blood flow; Pp/Ps = pulmonary blood pressure / systemic blood pressure;
Max. = maximal; Aff = affected; y = years; m = months; M = male; Gr. = grade; LM = left main coronary artery; RA = right atrium; d = days; RCA = right coronary artery; n.a. = not available;
F = female; LAD = left anterior descending coronary artery; RV = right ventricle; RVOT = right ventricular outflow tract; MPA = main pulmonary artery.
Age/Sex
Patient
Table 1. Clinical symptoms, signs, fistula type, catheterization, and angiographic findings of patients with coronary arteriovenous fistula
Pediatric Coronary Arteriovenous Fistula
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N.K. Wang, L.Y. Hsieh, C.T. Shen, et al
A
B
Fig. 1. A) Case 2: The fistula originates from the proximal part of the right coronary artery (RCA) and drains into the right atrium in a patient
with proximal coronary arteriovenous fistula (CAVF). B) Case 8: The full length of the left anterior descending coronary artery (LAD) is dilated
and tortuous and drains into the right ventricular apex in a patient with distal CAVF.
A color Doppler echocardiogram performed 6
months after operation revealed a tiny residual shunt
in one patient (Case 4), who originally had a diagnosis
of two fistulous terminations. Another patient (Case 6)
underwent a second angiography 12 years after surgery.
The angiogram revealed persistence of aneurysmal
dilatation of the left main coronary artery, LAD, and
coronary ostium. Thrombi and calcifications were found
at the mid and distal portion of the LAD in this patient
(Fig. 3). The contrast medium was regurgitated into
A
the aortic root from the left coronary artery during
each ventricular systole. Her ventriculogram revealed
ventricular aneurysm and a moderate degree of mitral
regurgitation. The angiogram of another patient (Case
8), who had distal CAVF, revealed thrombosis and
complete occlusion of the mid and distal portion of the
LAD 2 years after operation. The proximal portion of
the LAD was still abnormally dilated. Her left ventriculogram showed apical aneurysm, although she had no
clinical history of chest discomfort. One patient (Case
B
Fig. 2. A) Frontal and B) left lateral projections of the aortogram in case 7 show that both the right and left coronary arteries originate from
the left sinus. The right coronary artery straddles across the anterior wall of the right ventricular outflow tract. The diameter of the proximal
left anterior descending coronary artery (LAD) is enlarged, and a dilated branch terminates abruptly (arrow) and shunts into the right ventricle.
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Pediatric Coronary Arteriovenous Fistula
A
B
C
Fig. 3. Case 6: A) Preoperative aortogram reveals that the left anterior descending coronary artery (LAD) is markedly dilated and aneurysmally
transformed with a maximal caliber of 40 mm. The fistula drains into the right ventricular (RV) apex. B) Postoperative follow-up coronary
angiogram 12 years after operation reveals that the aneurysmal LAD remains the same; however, thrombi (Th) inside the mid portion of the
LAD and calcification (Ca) along the distal arterial wall are also seen. In addition, blood is regurgitated from the left main coronary artery
via a dilated coronary ostium to the aortic root during each ventricular systole (arrow). C) Left ventriculogram shows an apical aneurysm (An)
present both before and after fistula surgery.
9) experienced recanalization 7 years after a fistula
operation. This abnormal connection had disappeared
without surgical intervention 3 years after the appearance of recanalization.
Discussion
Most CAVFs found accidentally in adult patients during
routine cardiac catheterization are murmurless and symptom free. The amount of fistulous shunt is usually limited.
However, among our 10 pediatric patients, six had continuous murmur and four had systolic murmur. The Qp/
Qs ratio was greater than 1.5 in six of the eight patients for
whom data were available. In our series, newborns and
small infants with congenital CAVF tended to develop
congestive heart failure, as was previously reported by
Schumacher et al [2]. The fact that older children and
adults with CAVF have a much lower incidence of heart
failure suggests that the small amount of their shunts
enables them to survive to an older age.
In our series, color Doppler echocardiography was
shown to be a sensitive and excellent tool to detect CAVF,
as was previously reported by Ke et al [7]. Color Doppler
echocardiography can clearly delineate the origin,
termination, and course of CAVF. All eight diagnoses of
CAVF based on color Doppler echocardiography were
subsequently confirmed by cardiac catheterization and
angiography. However, the resolution of color Doppler
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echocardiography could not identify multiple fistulous
terminations in the three patients who underwent intracardiac repair. Nor could the subsequent angiography
identify multiple terminations. Therefore, we suggest
that surgeons must check the possible terminations carefully and make sutures complete [8–10]. The finding of
residual shunts immediately after surgery would suggest
an undiscovered and unsutured termination.
Whether regression of abnormally dilated vessels occurs after surgery is a major concern [1, 8, 11]. Abnormally dilated vessels became smaller in only one of the six
patients with proximal CAVF, while the other patients
had persistently dilated and tortuous coronary arteries
and fistulas. None of these six patients experienced coronary thrombosis and myocardial injury after surgery. In
contrast, both patients (Cases 6 and 8) who had distal
CAVF developed coronary thrombosis, calcification, and
ventricular aneurysm postoperatively. Their affected coronary arteries were still aneurysmally dilated.
Our findings suggest that distal CAVF has a greater
tendency to develop coronary thrombosis and ensuing
myocardial injury after operation compared with proximal CAVF. This is because the cessation of shunting
after ligation of the fistula terminals results in a decrease in the amount of blood flow in the affected
coronary arteries. This causes a dramatic decrease in
blood velocity in the abnormally dilated vessels, which
is an ideal condition for thrombus formation. Thrombi
may dislodge, drain to distal coronary arteries, and
cause myocardial injury. In contrast, ligation of proximal fistulas eliminates the steal phenomenon.
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N.K. Wang, L.Y. Hsieh, C.T. Shen, et al
Therefore, the amount of blood flow and velocity in the
distal coronary arteries increase.
In addition to the persistence of coronary dilatation
and the development of coronary thrombosis, blood
regurgitation from the dilated coronary artery to the
ascending aorta observed in Case 6 was an unusual finding.
The clinical significance of this abnormal regurgitation is
not clear. However, it may have enabled the blood clot
inside the coronary artery to be carried out and drained
into the systemic circulation. This finding suggests that
antiplatelet therapy should be taken into consideration.
Further observation for the regurgitation phenomenon
and its complications is needed.
In conclusion, in comparison to adults, pediatric
patients with CAVF tend to be symptomatic. Ligation of
the fistulous termination alone does not restore the
affected vessels to their normal size and shape. Longterm follow-up of CAVF patients is essential because
the clinical course and outcome are extremely variable.
Postoperative antiplatelet therapy is recommended,
especially in patients with distal CAVF and abnormally
dilated coronary arteries.
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