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ilio - iliac arteriovenous fistula ( avf ) is a rare disease that occurs in less than 1% of all common iliac artery aneurysms ( ciaas ) and in 27% of ruptured aneurysms .
surgical repair of an avf resulting from a ruptured abdominal aortic aneurysm ( aaa ) was first described by cooley in 1955 , and several similar cases have since been reported . nevertheless , perioperative mortality in patients with aaas with avfs is still as high as 67% in some series .
preoperative diagnosis of avf is difficult , and control of venous bleeding during open surgery can affect surgical outcome .
here we report a case of a contained rupture of a left ciaa with an ilio - iliac avf that was diagnosed preoperatively and successfully treated via surgery .
an 86-year - old man was admitted to a local hospital because of a temporary loss of consciousness and left leg edema . his medical history was unremarkable .
plain computed tomography ( ct ) showed enlargement of the abdominal aorta and left common iliac artery ( cia ) , and he was transferred to our institution for further evaluation and treatment . upon admission ,
the patient s blood pressure was 130/76  mmhg , and his heart rate was 88 beats / min . a pulsatile abdominal mass with vascular murmur and thrill was noted .
the left lower leg was considerably swollen compared with the lower right leg ( left : 37.0  cm , right : 34.4  cm ) .
no clinical signs of high - output heart failure , including hepatomegaly , jugular vein dilatation , and pleural effusion , were observed .
blood test results ( hemoglobin , 10.4  g / dl ; hematocrit , 30.9% ) indicated anemia .
arterial phase ct ( ge optima ct 660 , ge healthcare , tokyo , japan ) of the abdominal and pelvic vessels using a contrast agent ( omnipaque , 300  mg / ml ; daiichi sankyo pharma , tokyo , japan ) showed an infrarenal aaa ( maximum diameter , 60  mm ) and a left ciaa ( 70  mm ) complicated by a pressed left common iliac vein ( civ ) .
early appearance of contrast medium in the dilated left civ was notable and indicated the presence of an ilio - iliac avf ( fig .
1 ) . an abdominal echo revealed a mosaic flow , suggesting a shunt between the left cia and civ ( fig .
the clinical presentation and imaging findings led to the diagnosis of a contained rupture of the left ciaa exploding into the left civ .
after proximal and distal control of the aneurysm was obtained , the aneurysm was opened longitudinally , and intramural thrombi were removed . opening
venous bleeding was controlled via balloon occlusion ( tmp balloon catheter 9 fr , tokai medical products inc . ,
the avf was approximately 10  mm in diameter and was closed directly via continuous suture using 40 monofilament , non - absorbable polypropylene thread ( ethicon inc . ,
somerville , nj , usa ) . a dacron bifurcated graft [ intergard 16    8  mm , intervascular s.a .
( maquetcardiovascular , la ciotat , france ) ] was anastomosed proximally to the infrarenal aorta and distally to the right cia and the left external iliac artery .
the left internal iliac artery was closed directly , and the inferior mesenteric artery was reconstructed by anastomosing the left leg of the graft .
postoperative contrast - enhanced ct revealed a patent graft and absence of the avf ( fig .
3a ) ; however , magnetic resonance venography showed left iliac vein occlusion and significant collateral circulation ( fig .
abdominal avfs are anomalous passageways between the abdominal aorta , iliac artery , or renal artery and the inferior vena cava , iliac vein , or renal vein .
they result not only from aneurysmal diseases ( primary cause ) , but also from iatrogenesis , malignancy , and trauma such as gunshot wounds ( secondary causes ) .
although rare , abdominal avfs can be life - threatening , and intensive care management and urgent treatment consisting of open surgery or endovascular repair are occasionally required . in their review of case reports , mcauley et al . identified three symptoms consistently associated with the presence of an avf : ( 1 ) high - output cardiac failure with a precipitous onset , ( 2 ) a pulsatile abdominal mass accompanied by a thrill and a bruit , and ( 3 ) unilateral lower - extremity ischemia or venous engorgement . however
a variety of symptoms appear depending on the size and location of the avf , time after the rupture , cardiopulmonary function , and bleeding into the retroperitoneum .
several case reports recommend the use of ct or duplex ultrasound as a means of diagnosing avfs .
any combination of imaging modalities , such as contrast - enhanced ct and abdominal ultrasonography , as used in this case , are useful , especially for regional diagnosis of avf .
unresolved issues in open repair , which was performed in our study , include the control of venous bleeding and the prevention of pulmonary embolisms caused by debris or air . in the present case ,
a balloon occlusion catheter was used to minimize intraoperative bleeding from the fistula , as previously reported .
however , we suggest that the balloon technique be considered as a stand - by procedure in open repair
. it may be particularly useful when the avf is large or the vessel wall is fragile .
treatment of aneurysms with avfs via endovascular repair has become increasingly more common in recent years . compared with open repair ,
it is less invasive , and the risk of major blood loss during treatment is low .
however , its long - term performance is still unknown . in a systematic review ,
the longest follow - up time after endovascular repair was 24 months , and the mean follow - up time was only 9 months .
endovascular repair also carries the risk of type 2 endoleak due to venous bleeding through the avf and consequent expansion of the aneurysm .
conclusions regarding this procedure require long - term follow - ups and randomized controlled trials with large case numbers . in the current case , the patient s anatomy was unsuitable for endovascular treatment , and technical difficulties due to avf coil embolization were envisioned .
if his anatomy had been suitable , endovascular repair would have been considered as an initial therapy in view of his age .
notably , in the present case , there was no sign of high - output heart failure throughout the treatment course .
postoperative magnetic resonance venography indicated blood flow failure of the left iliac vein due to compression of the aneurysm .
we conclude that the main cause of the swelling in the left leg was not due to left iliac vein occlusion but to an avf , because the swelling was immediately reduced after surgery .
we report the successful surgical treatment of an ilio - iliac avf associated with a ruptured ciaa . using the balloon occlusion technique
definitive diagnosis of avf is sometimes difficult , because subjective symptoms and objective findings can be caused by various conditions .
use of multiple imaging modalities facilitates correct preoperative diagnosis in early disease stages and consequently improves surgical outcome .
written informed consent was obtained from the patient for publication of this case report and accompanying images .
a copy of the written consent is available for review by the editor - in - chief of this journal on request .
makoto iijima : study design , data collection , data analysis , and manuscript preparation .
highlightswe report the successful surgical treatment of an ilio - iliac arteriovenous fistula.although rare , this disease can be life-threatening.use of multiple imaging modalities facilitates correct preoperative diagnosis.balloon occlusion technique is used to minimize blood loss during open repair.there was no sign of high - output heart failure because of venous flow failure .