Abstract
Rupture with fistulization of an abdominal aortic aneurysm with the vena cava is a rare complication and typically presents with congestive cardiac failure. Embolization of a thrombus from the aneurysm into the vena cava can however present in the absence of failure symptoms which can make it difficult to diagnose clinically without cross sectional imaging.
Keywords: Aortocaval fistula, Congestive heart failure, Computed tomography
Description
A 50-year-old male who was a known case of chronic kidney disease presented to the emergency with acute pain abdomen. On examination, he had a pulsatile swelling in the abdomen with a blood pressure of 110/60 and a heart rate of 100. No congestive heart failure (CCF) symptoms or respiratory distress was present. Ultrasound revealed an abdominal aortic aneurysm with free fluid in the pelvis suggesting possible rupture. An echocardiography did not reveal any abnormality. Computed tomography (CT) angiogram done on a 192 × 2 slice dual source scanner (Siemens Somatom Definition Force, Germany) showed a ruptured abdominal aortic aneurysm (AAA) with an aortocaval fistula (ACF) (Fig. 1a, b). No pulmonary emboli were noted on CT. The absence of CCF was explained by the presence of inferior vena cava (IVC) thrombus at the level of the left renal vein, which possibly prevented the development of CCF (Fig. 1c, d). The patient underwent an open repair of the AAA with over-sewing of the fistula from the aortic end.
Fig. 1.
Volume rendered (a) and coronal maximum intensity projection (b) computed tomography image showing abdominal aortic aneurysm (*) with aortocaval fistula (dashed arrow) and caval thrombus (arrow). Axial image (c) showing the ruptured abdominal aortic aneurysm with peripheral thrombus (*) and the aortocaval fistula (dashed arrow). Axial CT image (d) showing the near occlusive caval thrombus
Spontaneous ACF is rare with an estimated incidence of 1–4% [1]. ACF usually presents with a pulsatile abdominal swelling with high-output cardiac failure. Very rarely, features of hyperdynamic circulation may not be present, as in our case. Despite the advancements in the endovascular treatment, it is still associated with complications. Hence, open repair is still preferred when the patient is fit enough to undergo surgery and when endovascular treatment is available [2, 3]. The pre-operative diagnosis of ACF is important when planning AAA repair as manipulation of the aneurysm before clamping can result in further embolization of the thrombus. This case highlights the critical role of CT angiography in detecting the ACF and the thrombus, and thus, in deciding the surgical plan. CT in this case also helped to explain the reason for lack of CCF.
Authors’ contributions
All the authors contributed equally in preparation, design, and final approval of the manuscript.
Funding
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Conflict of interest
The authors declare that they have no conflict of interest.
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Exempt.
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Obtained.
Footnotes
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References
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