Intra-aneurysm Sac Pressure – The Holy Grail of Endoluminal Grafting of AAA

AbstractObjectives: to relate intra-aneurysm sac pressure during endoluminal AAA repair to early and late endoleak, as well as to the aneurysm size upon follow-up.Design: prospective clinical investigation.Methods and patients: in 46 patients who had their AAAs treated by a stent graft (group I), intra-operative pressure measurement was performed (aorto uni-iliac stent grafts: 25 cases, bifurcated stent grafts: 21 cases). In 18 patients with open repair (group II) flow in the inferior mesenteric artery, and the pressure in the aneurysm sac was measured, before and after aortic and iliac cross clamping. Values are given in median with range.Results: in group I, complete exclusion of AAA (no endoleak on intra-operative control angiogram) resulted in a statistically significant decrease in mean sac pressure from 74 (55–101) to 47 (4–104)mmHg. Pulse pressure reduced from 67 (34–103) to 8 (0–74)mmHg. In 11 patients a proximal type I endoleak was sealed by balloon modeling, after which the mean sac pressure reduced from 63 (14–91) to 52 (4–74)mmHg (n.s. versus patients with primary seal). Intra-operative pressure did not correlate with change in AAA diameter during twelve months follow-up. In group II, cross clamping of the proximal aorta significantly reduced mean sac pressure to 32 (21–55)mmHg, and the pulse pressure to 0 (0–13)mmHg (p