In vitro analysis of modular aortic stent-graft failure.
OBJECTIVE
To investigate the theoretical forces involved in and the nature of fixation between the modular components of a variety of aortic stent-grafts.


METHODS
An in vitro study of 6 aortic stent-grafts was performed using a tensometer. The modular stent-graft components were distracted until the iliac limb was completely separated from the main body. Tests were repeated at least 6 times for each stent-graft.


RESULTS
The maximum pullout force was 36.0 N using the Fortron stent-graft, which resulted in stent-graft disintegration. The maximum median forces of the other stent-grafts were 23.7 N (19.9-31.2) for the Aorfix, 7.3 N (6.9-7.6) for the AneuRx, 7.0 N (6.8-7.1) for the Zenith BiFab, 5.4 N (5.0-6.5) for the Talent, and 2.4 N (2.2-2.4) for the Vanguard II CONCLUSION: The results of this in vitro study suggest that current forms of iliac limb fixation in modular aortic stent-grafts are adequate provided the components are deployed with sufficient overlap. However, for many of the stent-grafts tested, the safety margin was small.
Hinchliffe
Robert J
RJ
Department of Vascular and Endovascular Surgery, University Hospital, Nottingham, UK. robhinchliffe@hotmail.com
Natarajan
Sukin
S
Hopkinson
Brian R
BR
D001014:Aortic Aneurysm / Q000601:surgery; D019917:Blood Vessel Prosthesis Implantation; D007083:Iliac Artery / Q000601:surgery; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D015607:Stents / Q000145:classification*; D013718:Tensile Strength