Geometrical modelling of abdominal aortic aneurysms

Abstract

Stent graft combination devices have been developed as a new alternative for treating abdominal aortic aneurysms. The major risk using this new technique with standard devices is the perigraft leak. In order to choose a suitable graft for each patient, and thus avoid such a risk, we have developed a program which provides three-dimensional representations of such aneurysms.

Images of abdominal regions are obtained by spiral C.T. These images are then transferred to a graphics workstation and processed to provide sets of contours which represent the shape of the aorta and other vessels. Then, a surface joining all these contours is computed; we obtain a treelike structure represented as a set of generalized cylinders which are joined by means of free-form surfaces. Such geometrical models provide an efficient mathematical support for further developments involving diagnosis, surgery and endoprostheses design.