Impending rupture of abdominal aortic aneurysm due to spontaneous obstruction of aortocaval fistula after endovascular abdominal aortic aneurysm repair

Abstract

Endovascular aortic aneurysm repair (EVAR) is a valid treatment for patients with abdominal aortic aneurysm with aortocaval fistula. However, an endoleak can be caused by persistent communication between the aneurysm and the inferior vena cava. We present a case of impending rupture due to spontaneous obstruction of an aortocaval fistula after EVAR. Spontaneous obstruction of an aortocaval fistula is rare; however, when occurs, it will cause an endoleak, followed by dilatation or impending rupture of the abdominal aortic aneurysm. EVAR alone for aortocaval fistula will sometimes not be adequate if the type II endoleak is patent.

Keywords: Abdominal aortic aneurysm; Aortocaval fistula; Endovascular aortic aneurysm repair.

Fig 1

Computed tomography (CT) angiogram at the first operation. A, Preoperative CT scan showing abdominal aortic aneurysm (AAA) and aortocaval fistula (ACF; arrow). B, Postoperative CT scan showing a type II endoleak and persistent communication between the AAA and inferior vena cava (IVC); however, the aneurysm sac had shrunk. C, Three-dimensional CT angiogram showing persistent communication (arrow) via a meandering mesenteric artery (open arrow).

Fig 2

Computed tomography (CT) angiogram at the present admission (4 months after the first operation). CT scan revealing type II endoleak (arrow; A), rapid dilatation of the aneurysm sac (maximum transverse diameter had increased by 15 mm after first operation) and spontaneous obstruction of the aortocaval fistula (ACF; B). C, Three-dimensional CT angiogram showing disappearance of ACF (open arrowhead indicates type II endoleak via a meandering mesenteric artery).

Fig 3

Postoperative computed tomography angiogram showing disappearance of type II endoleak (A) and shrinkage of aneurysm sac (maximum transverse diameter decreased by 9 mm; B). C, Three-dimensional CT scan showing disappearance of type II endoleak.