Biomed Imaging Interv J 2006; 2(2):e13
© 2006 Biomedical Imaging and
Spontaneous internal ilio-iliac fistula in an elderly woman
presenting as heart failure
MRad, BJJ Abdullah1,
MBBS, FRCR, S Kunanayagam2,
1 Department of Biomedical Imaging (Radiology),
Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
2 Department of Medicine, Faculty of Medicine, University of Malaya,
Kuala Lumpur, Malaysia
Acquired intra-abdominal arteriovenous fistulas (AVFs) are a
rare disorder where the communication most commonly occurs between abdominal
aorta and inferior vena cava. Ilio-iliac AVF has been reported previously, but
is exceedingly rare. We present a case of spontaneous ilio-iliac AVF in an
elderly woman who presented with symptoms of right heart failure where the
diagnosis was not considered. The computed tomographic (CT) and angiographic
features are described. The current status of management as well as a review of
the literature is also presented. � 2006 Biomedical Imaging and
Intervention Journal. All rights reserved.
Keywords: Ilio-iliac fistula; heart failure; CT;
An 81-year-old woman presented with palpitations,
breathlessness and bilateral lower limb swelling one month prior to admission.
Her symptoms had worsened five days prior to admission. She had a history of paroxysmal
supraventricular tachycardia (SVT). There is no history of previous surgery,
severe abdominal pain, penetrating or blunt trauma to the abdomen.
On admission, she was tachypnoeic. Her blood pressure was
120/80 mmHg. Her jugular venous pressure was raised with bilateral basal lung
crepitations and bilateral lower limb pitting oedema to the level of the knees.
A systolic murmur was heard at the apex of the heart. Hepatomegaly was also
found. There was also a pulsatile mass per abdomen, which was clinically
consistent with an abdominal aortic aneurysm.
Electrocardiogram (ECG) showed that the patient was in
atrial fibrillation. Chest radiograph showed cardiomegaly with fluid in the
left oblique fissure and prominent hilar vessels. A clinical diagnosis of
congestive cardiac failure secondary to atrial fibrillation was made. In view of
the pulsatile abdominal mass, an ultrasound examination of the abdomen was
performed on the same day to assess the size of the abdominal aortic aneurysm.
The right atrium, inferior vena cava and hepatic vein were enlarged along with
ascites consistent with right heart failure. The abdominal aorta was ectatic
and aneurysmal with the widest diameter measuring 3.7 cm. An echocardiogram,
performed for further assessment of the cardiac function, showed moderate
tricuspid regurgitation with enlarged right atrium and ventricle. Left
ventricular function was satisfactory, with an ejection fraction of 61%.
Two days after admission, CT angiogram of abdominal aorta
was performed (GE High-speed, Milwaukee, WI) for further assessment of the
aneurysm. The angiogram confirmed the findings of a grossly dilated right
atrium and aneurysmal abdominal aorta. Furthermore, multiple markedly dilated
vessels were noted in the pelvis, with a fistulous communication between the
right internal iliac artery and vein (Figures 1, 2 and 3). A digital
subtraction angiogram via a left branchial artery puncture of the right
internal iliac artery confirmed the presence of a large fistulous communication
between the right internal iliac artery and vein (Figure 4a). Both the right
internal iliac artery and vein were tortuous and dilated. Superselective
catheterisation of right internal iliac artery using micro-catheter (for better
assessment of the location and size of the fistula) was performed as it was not
possible to confirm the site of the fistula using the 4F Cobra catheter (Figure
4b). Embolisation of the fistula was not feasible due to its large size,
extremely tortuous vessels, short neck, and high-flow. The patient was
considered a poor candidate for surgery due to a poor premorbid status,
advancing age and her reluctance and fear. Patient was discharged following
treatment of heart failure.
[View this figure]
Contrast enhanced Axial CT at the level of the pelvis. (a) The enlarged tortuous right iliac artery (arrow) and right internal iliac veins (asterisk); (b) Axial image at a lower level shows the AV fistula (arrow) from aneurysmal right internal iliac artery into the internal iliac vein. Dilated veins on either side (asterisk).
[View this figure]
Coronal reconstruction of CT scan shows tortuous atherosclerotic aneurysmal abdominal aorta (A), right common (thick arrow) and internal iliac arteries (thin arrow) and origin of the right external iliac artery (arrowhead).
[View this figure]
3D reconstruction of CT scan clearly shows markedly dilated right common and internal iliac artery (arrowhead) and normal right external iliac artery (arrow). The dilated tortuous right internal and common iliac veins are also noted (asterisk). The normal contralateral left internal iliac artery shown (thin arrow). A is aorta; V is inferior vena cava.
[View this figure]
Digital subtraction angiogram. (a) Selective catheterisation of the right internal iliac artery (thin arrow) shows enlarged tortuous vessel with rapid filling of ectatic the right internal vein (thick arrow) via the fistula (asterisk); (b) Selective catheterisation of the distal right internal iliac artery with a microcatheter (thin arrow) shows large short fistulous tract (arrowhead) with some filling of ectatic the right internal vein (asterisk).
Arteriovenous malformations (AVMs) of the female pelvis are
uncommon. These may either be congenital or acquired. Congenital pelvic AVMs
are characterised by a large number of arterial feeding branches. The arterial
feeders are considered undifferentiated vascular structures following arrested
embryonic development at various stages . Acquired pelvic AVMs on the other
hand, develop following spontaneous rupture of an atherosclerotic aneurysm into
the adjacent veins or following penetrating trauma (less than 20%), e.g.
gunshot wound or stabbings, or after lumbar disc surgery . Therefore,
acquired AVMs are most commonly arteriovenous fistulas (AVF). The AVFs are most
commonly aorto-caval fistula, followed by ilio-iliac  and aorto-iliac.
However, the aetiology, clinical features, pathophysiology, principles of
management and postoperative care for these fistulas are similar. Approximately
3 to 4% of all patients undergoing surgery for ruptured aorto-iliac aneurysm
are found to have AVF . These carry a better prognosis than intraperitoneal,
retroperitoneal or enteric rupture of aorto-iliac aneurysms . The disorder
has a marked male preponderance . Other rarer causes of acquired AVFs
include Marfan�s syndrome, Ehler-Danlos syndrome, syphilis, Takayasu�s
arteritis, invasion by malignant tumour  and in some the cause is never
Pelvic AVMs may manifest with symptoms of pain, haemorrhage,
haematuria, dyspareunia, or congestive heart failure, or symptoms secondary to
mass effect on adjacent pelvic structures. Acquired AVF, secondary to surgery
or trauma, tend to occur in younger patients as trauma or surgery tends to
affect younger patients. In contrast, spontaneous perforation of atherosclerotic
aneurysm into adjacent veins tends to occur in the older population. Two large
series report mean ages of 67.3  and 69.7 years. The time of onset of
symptoms is usually earlier, from hours to weeks . The initial diagnosis is
often that of an abdominal aortic aneurysm, AVF is often not suspected and
often the diagnosis is only made at surgery .
Iliac artery aneurysms and ilio-iliac fistulas are usually
associated with abdominal aortic aneurysm, as demonstrated in this case, though
they may occur as isolated entities. Rupture of atherosclerotic aneurysms into
the iliac vein may have three different clinical manifestations: sudden onset
of high output cardiac failure; pulsatile lower abdominal mass associated with
bruit and thrill; or unilateral intermittent claudication or venous congestion.
Our patient presented with the first two clinical manifestations and the
tricuspid regurgitation was most likely secondary to grossly dilated ventricle
from high output cardiac failure.
Ultrasound, CT or even MRI is almost always ordered for
assessment of the abdominal/iliac aneurysms. Colour Doppler ultrasound has
demonstrated the AV fistulas as areas of high velocity turbulent flow with
aliasing of colour signal and also shows any associated thrombus at the
aneurysm or fistula. Detection of ilio-iliac fistulas may however be difficult,
as demonstrated by this case, as these tortuous and aneurysmal vessels lie deep
within in the pelvis and obscured by overlying bowel gas. CT angiography is
excellent in demonstrating the aneurysm and fistulous communications ,
especially with the advent of multi-detector CT and 3D software. Early contrast
opacification of the iliac veins and inferior vena cava, and site of the
fistula are clearly visualised.
Conventional angiography still remains the �gold standard�
for assessment of AVMs as well as assisting in assessing options for
endovascular management. Endovascular treatment has gained considerable favour
in the management of arteriovenous fistula especially for those with
significant high-risk comorbid factors.� Options available include percutaneous
endovascular treatment with covered self-expanding stent graft to cover the mouth
of the fistula. However, this is not always feasible due to the tortuous iliac
vessels. Transcatheter embolisation with coils or detachable balloons  is
generally not recommended due to the large size of the fistula, high flow and
short neck. Surgical options for AVF consist of endo-aneurysmal repair of the
fistula and prosthetic graft replacement of the aortoiliac aneurysm but these
are associated with high morbidity and mortality (approaching 60%) due to the
emergent nature of the procedure . Thus early diagnosis and appropriate
management is of paramount importance.
Unlike acquired AVFs, surgical treatment of congenital AVMs
is difficult due to the extensive nature and the large number of dysplastic
feeder vessels with the potential for exsanguinating haemorrhage and damage to
surrounding structures . Accordingly, transcatheter embolisation has become
the treatment of choice . Preoperative embolisation of AVMs has also been
used as an adjunct to decrease intraoperative blood loss. Small asymptomatic
AVMs that do not increase in size may be safely observed.
AVFs between major abdominal vessels are uncommon
complication of aortoiliac aneurysm. Ilio-iliac fistula in a female patient is
even rarer and associated with high morbidity and mortality especially if the
diagnosis is not suspected. In this patient, in the absence of history of
trauma or surgery and the presence of extensive aneurysmal disease involving
the aorta and iliac arteries, it is reasonable to believe that the AV fistula
was secondary to perforation of the aneurysmal right iliac artery into the
right iliac vein. In addition to the rapid onset, the presence of a single
communication and older age group lend more support to this diagnosis. There
has only been a single reported case in the literature with an ilio-ilial
fistula secondary to atherosclerotic disease . In addition the CT
angiographic appearances of ilio-ilial AVF have not been described.
Diwan RV, Brennan JN, Selim MA, et al. Sonographic diagnosis of arteriovenous malformation of the uterus and pelvis. J Clin Ultrasound 1983;11(5):295-8.
Farid A, Sullivan TM. Aortocaval fistula in ruptured inflammatory abdominal aortic aneurysm. A report of two cases and literature review. J Cardiovasc Surg (Torino) 1996;37(6):561-5.
Kazmier FJ, Harrison CE Jr. Acquired aortocaval fistulas. Am J Med 1973;55(2):175-83.
Ghilardi G, Scorza R, Bortolani E, et al. Rupture of abdominal aortic aneurysms into the major abdominal veins. J Cardiovasc Surg (Torino) 1993;34(1):39-47.
Davis PM, Gloviczki P, Cherry KJ Jr, et al. Aorto-caval and ilio-iliac arteriovenous fistulae. Am J Surg 1998;176(2):115-8.
Adili F, Balzer JO, Ritter RG, et al. Ruptured abdominal aortic aneurysm with aorto-caval fistula. J Vasc Surg 2004;40(3):582.
Yilmaz S, Erdogan A, Luleci E. Transvenous embolization and stent placement for an internal iliac arteriovenous fistula with central iliac vein occlusion. J Vasc Interv Radiol 2004;15(4):399-404.
Jacobowitz GR, Rosen RJ, Rockman CB, et al. Transcatheter embolization of complex pelvic vascular malformations: results and long-term follow-up. J Vasc Surg 2001;33(1):51-5.
Received 9 July 2005; received in revised form 29 September 2005; accepted 14 February 2006
Department of Biomedical Imaging (Radiology), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia. Tel.: +603-79502069; Fax.: +603-79581973; E-mail: email@example.com (Basri J.J. Abdullah).
Please cite as:
Tan GP, Abdullah BJJ, Kunanayagam S,
Spontaneous internal ilio-iliac fistula in an elderly woman presenting as heart failure,
Biomed Imaging Interv J 2006;2(2):e13
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