Creation of individual ideally shaped stents using multi-slice CT: in vitro results from the semi-automatic virtual stent (SAVS) designer

Abstract

To plan stent-grafting for thoracic aortic aneurysm with complicated morphology, we created a virtual stent-grafting program [Semi Automatic Virtual Stent (SAVS) designer] using three-dimensional CT data. The usefulness of the SAVS designer was evaluated by measurement of transformed anatomical and straight stents. Curved model images (source, multi-planer reconstruction and volume rendering) were created, and a hollow virtual stent was produced by the SAVS designer. A straight Nitinol stent was transformed to match the curved configuration of the virtual stent. The accuracy of the anatomical stent was evaluated by experimental strain phantom studies in comparison with the straight stent. Mean separation length was 0 mm in the anatomical stent [22 mm outer diameter (OD)] and 5 mm in the straight stent (22 mm OD). The straight stent strain voltage was four times that of the anatomical stent at the stent end. The anatomical stent is useful because it fits the curved structure of the aorta and reduces the strain force compared to the straight stent. The SAVS designer can help to design and produce the anatomical stent.

A device for stent designing in emodynamic surgery room

“…In [8] the ability to assess the coronary artery lumen is measured in the presence of coronary artery stents in multislice spiral computed tomography. In [9] a computer program called Semi Automatic Virtual Stent (SAVS) designer is exploited to plan stent-grafting for thoracic aortic aneurysm with complicated morphology in order to guide the real stent implantation. Most of the times the angiographer generates planar images, which means that the physician has to choose the most reliable planar projection of the vessel in order to perform reliable measurements.…”

Cartesio: A Software Tool for Pre-implant Stent Analyses

“…In [7] the accuracy of 16-row multidetector computed tomography is measured when used to visualize peripheral artery stents and to the appraise instent stenoses. In [12] a computer program is exploited to plan stent-grafting for thoracic aortic aneurysm with complicated morphology. The program, called Semi Automatic Virtual Stent (SAVS) designer, uses three-dimensional computed tomography data to allow the design of a virtual stent which can be used as a guide to shape a real straight stent to be implanted.…”

Thoracic stent-graft

“…Some stent-grafts are manufactured in a curved shape in an attempt to accommodate the aortic curvature. A computeraided design system for creating the ideal curvature is under investigation 5 .…”

“…In a tortuous aorta, it is difficult to insert the stent-graft and fix the distal end to the vessel wall. A straight region of the aortic wall should be chosen for the stent-graft landing site, or an anatomically pre-shaped stent-graft should be used 5 .…”