Nonoperative approach to endotension

The necessity of operative treatment of endotension after endovascular grafting of abdominal aortic aneurysms (endovascular aneurysm repair; EVAR) is under debate. The proposed causes of endotension and related treatment protocols are controversial. We report the outcome of a nonoperative approach to five patients with endotension after EVAR.

From February 1997 to August 2004, 160 patients who underwent EVAR of an infrarenal abdominal aortic aneurysm were evaluated for the incidence of endotension. According to the endovascular protocol, plain radiographs, spiral computed tomography, and angiography were performed before and after surgery for follow-up. To detect endotension, spiral computed tomography was performed by using a delayed imaging technique after the infusion of contrast medium. Endotension was defined as an aneurysm sac enlargement after EVAR without evidence of endoleak. Aneurysm sac rupture was defined as discontinuity of the calcific rim of the aneurysmal sac and the presence of intra-aneurysmal fluid outside the sac.

We found five (3.1%) patients with endotension. Three of these experienced aneurysmal sac rupture. Only one of the three was underwent operation on experiencing sudden intestinal occlusion due to intra-abdominal adhesions. This patient had no intra-abdominal or retroperitoneal bleeding or hematoma but died after intensive care as a result of non-aneurysm-related problems. Four patients with endotension are still being closely followed up according to our surveillance protocol, and they are doing clinically well. After rupture, clear shrinking of the aneurysm sac was seen in two patients.

Endotension after EVAR may cause subsequent aneurysm rupture. Endotension is evidently not associated with endoleak I to III provided that the endovascular graft is maintained in appropriate position and that free endovascular flow is observed. We propose to consider a nonoperative approach in the clinically asymptomatic patient with aneurysm enlargement after EVAR if endoleak is excluded by well-performed imaging techniques.