Yuminaga et al. Journal of Medical Case Reports 2012, 6:33 http://www.jmedicalcasereports.com/content/6/1/33 Page 4 of 6 Figure 4 Selective right carotid angiogram after three-minute common carotid artery balloon angioplasty, demonstrating no further contrast extravasation. incidence of aorto- or iliovenous fistula is rare and occurs in less than 1% of abdominal aortic aneurysm and 3% to 4% of ruptured abdominal aortic aneurysm [2,3]. The pathogenesis usually involves spontaneous rup- ture of a pre-existing aneurysm into the venous system or fistula development secondary to abdominal trauma or previous abdominal surgery, including abdominal aortic aneurysm repair and lumbar disc operation [1]. Other rare causes include mycotic aneurysm, syphilitic aneurysm and those associated with connective tissue disease, such as Ehler-Danlos syndrome [4]. In this case, two previous right femoral arterial punctures had been performed for coronary angiography. These may have contributed to the development of the iliocaval fistula. The exact etiology in this case is unknown, however the development of a pseudoaneurysm from femoral arterial catheterization with subsequent erosion into the venous system, or wire perforation into the venous system whilst manipulating a wire through an iliac artery aneur- ysm, both remain possibilities. Other possibilities Figure 5 Three-dimensional volume reconstruction of a postoperative computed tomography angiogram, demonstrating an excluded right common iliac artery aneurysm with an aortoiliac stentgraft extending into the right external iliac artery and retrograde filling of the distal right internal iliac artery. include an atherosclerotic or degenerative iliac artery aneurysm that had spontaneously eroded into the IVC and subsequently caused high output cardiac failure. This is the primary and most common cause of develop- ment of large vessel fistulas. The presentation of an iliocaval fistula can vary from an incidental mass to multiorgan failure. Classically, the patient presents with a triad of hypotension, pulsatile mass and heart failure [1,5]. Sometimes, the patient can present with congestive cardiac failure, leg edema and leg ischemia [5]. Gregoric et al. [6] first described a case of an aortocaval fistula presenting as acute renal failure. Since then, there have been only three cases [7-9] where the patient has presented with multiorgan failure. This is the second reported case of an endovascular repair of such a patient. This is the first case in which an endo- vascular graft was employed as the first line of treatment