Endotension: An Explanation for Continued AAA Growth after Successful Endoluminal Repair

Abstract

Purpose: To present and analyze several cases that illustrate persistent sac pressurization following endovascular abdominal aortic aneurysm (AAA) repair. Methods and Results: Four patients with successful endovascular AAA exclusion presented in follow-up with an expanding aneurysm. Two had initial sac diameter decrease, but by 18 and 24 months, respectively, the AAA had enlarged and become pulsatile. There was no endoleak evident, but the proximal attachment stents had migrated distally in both cases. One patient developed endoleak with aneurysm expansion at 6 months; contained rupture occurred at 12 months. The last case had slowly evolving aneurysm expansion over 36 months but no endoleak. All endografts were removed and successfully replaced with conventional grafts. Intrasac thrombus was implicated as the means of pressure transmission that precipitated AAA expansion in these cases. Conclusions: Excluded AAAs can increase in size owing to persistent or recurrent pressurization (endotension) of the sac even when there is no evidence of endoleak. One proposed mechanism is pressure transmission via thrombus that lines the attachment site. Endotension may also represent an indiscernible, very low flow endoleak that allows blood to clot at the source of leakage.

Aneurysmal sizing after endovascular repair in patients with abdominal aortic aneurysm: interobserver variability of various measurement protocols and its clinical relevance

“…As rupture is believed to result from systemic pressure in the aneurysmal sac, the most widely accepted criterion of clinical success is reduction of the size of the aneurysm. It is thought to be impossible to reduce the sac in cases of persistent pressurization of the aneurysmal sac [11]; therefore, for most series dealing with stentgraft placement to treat AAA, the results are presented according to the size of the aneurysm (i.e. the diameter of the AAA) [1,2,3].…”

Endoleakage after endovascular treatment of abdominal aortic aneurysms: diagnosis, significance and treatment

“…Type IV endoleak seal spontaneously. Type V endoleak or endotension Endotension (or Type V endoleak) corresponds to continued aneurysm expansion in the absence of a confirmed endoleak [12,13]. Type V endoleak may be due to undiagnosed endoleak, presumably with very slow flow and suboptimal imaging (e.g., no delayed helical CT acquisition).…”

Aortoenteric Fistula After Endovascular Stent Grafting for an Abdominal Aortic Aneurysm: Report of a Case

“…[10][11][12][13] The EVSG for this patient appeared to be successful since there was shrinkage of the AAA and no endoleak. However, continuous endotension, caused by an undetected endoleak or the transmission of pressure through a sealed thrombus, may have accelerated pressure necrosis.…”