Fenestrated and branched endografts: assessment of proximal aortic neck fixation.
OBJECTIVE
To investigate proximal fixation characteristics of different aortic endograft designs: a suprarenally placed fenestrated endograft, a modular branched endograft, an infrarenal endograft with suprarenal bare stent fixation, and the gold standard, a conventional hand-sewn anastomosis.


METHODS
Ten human cadaveric aortas were obtained at autopsy and transected 20 mm below the renal arteries to mimic an infrarenal aneurysm neck. In random order, the infrarenal, fenestrated, and branched endografts were deployed into the aorta. Using a hydraulic material testing machine, longitudinal load was applied to the distal end of each endograft until migration occurred, thus defining the displacement force (DF). Subsequently, a hand-sewn infrarenal anastomosis was tested in a similar manner.


RESULTS
The median DF was 4.67 N (3.82-6.37) for the infrarenal endograft, 9.17 N (8.03- 10.81) for the fenestrated endograft, and 16.95 N (14.78-19.67) for the branched endograft. The differences in DF between the infrarenal and fenestrated endografts and between the fenestrated and branched designs were statistically significant (both p=0.005). The median force to dislodge the graft from the conventional anastomosis was 89.16 N (71.24-105.23).


CONCLUSIONS
Suprarenally placed endografts, especially with additional branch grafts, provide improved proximal fixation compared to an infrarenal endograft with suprarenal bare stent fixation. However, none of the tested endografts approached the optimal, time-proven fixation, the hand-sewn anastomosis.
Linsen
Matteus A M
MA
Department of Surgery, VU University Medical Center, Amsterdam, The Netherlands.
Vos
A W Floris
AW
Diks
Jeroen
J
Rauwerda
Jan A
JA
Wisselink
Willem
W
D001012:Aorta, Abdominal / Q000601:surgery; D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods*; D002102:Cadaver; D006801:Humans; D011474:Prosthesis Design; D018709:Statistics, Nonparametric; D015607:Stents; D013314:Stress, Mechanical; D016896:Treatment Outcome