Impact of Intrasac Thrombus and a Patent Inferior Mesenteric Artery on EVAR Outcome

Abstract

Purpose:

To assess the significance of a patent inferior mesenteric artery (IMA) and presence of intrasac thrombus on the outcome of endovascular aneurysm repair (EVAR) for infrarenal abdominal aortic aneurysm (AAA).

Methods:

Between June 2004 and June 2007, 114 AAA patients (100 men; mean age 75 years, range 56–87) treated electively with a bifurcated stent-graft were assessed with computed tomography pre- and postoperatively. Incidences of type II endoleaks and reinterventions were compared with preoperative intrasac thrombus and IMA patency.

Results:

Over a mean follow-up of 19 months (range 6–38), there was no aneurysm rupture. Eleven (11%) of 101 patients with and 7 (54%) of 13 patients without preoperative intrasac thrombus presented with a type II endoleak (p<0.01). The postoperative change in aneurysm diameter was 0 mm (220 to 16) in 18 patients with type II endoleak and 29 mm (230 to 18) in sealed aneurysms (p<0.001). Fourteen (78%) type II endoleaks originated from lumbar arteries and 4 (22%) from the IMA in spite of the fact that most patients (69%) had a patent IMA. There were 5 reinterventions for type II endoleak with expansion of the sac. The reinterventions did not seem related to intrasac thrombus or a patent IMA. Prophylactic embolization of the IMA was unsuccessful in 4 (33%) cases.

Conclusion:

In this series, type II endoleaks inhibited sac shrinkage and occurred more frequently in aneurysms without intrasac thrombus. Most type II endoleaks originated from lumbar arteries and not from the IMA. Prophylactic embolization of the IMA does not seem justified and is not always technically successful.