Significance of perioperative intrasac pressure in sac shrinkage after endovascular abdominal aneurysm repair.

Although systolic intrasac pressure, described as systolic PI, was an independent risk factor for aneurysm sac shrinkage, contrary to our expectation, it was significantly higher in patients with aneurysm sac shrinkage than those without. This seemingly contradictory result may be explained by the properties of an aneurysm sac, which influence the change of intrasac pressure.