Endovascular management of the juxtarenal aortic aneurysm: can uncovered stents safely cross the renal arteries?
A short or otherwise suboptimal neck precludes the use of endovascular repair in 30% to 50% of patients with abdominal aortic aneurysms. Stent-graft fixation in an unsuitable neck carries the risk of technical failure owing to development of a proximal endoleak or stent-graft migration. Furthermore, in some patients, the neck dilates postoperatively. Endovascular healing with tissue incorporation into the graft material seems in and of itself insufficient to fixate the stent-graft adequately or to prevent neck dilation. Therefore, neck dilation is often associated with detachment of the stent-graft from the aortic wall, which is followed by the development of a proximal endoleak or stent-graft migration. Fixation of stent-grafts can be improved by placing the proximal stent above one or both of the renal artery orifices. Current experimental and clinical data suggest that renal function is not impaired by suprarenal aortic stents during the first year; however, this finding may not apply to all types of stents. Fixation of stent-grafts also may be improved by using stents with barbs that pierce the aortic wall. Additionally, the force that is exerted on the anchoring device may well be reduced by fully stented grafts with an associated increase in column strength. In the future, the risk of neck dilation and stent-graft dislodgement might also be limited by novel techniques such as laparoscopic banding of the neck or endoluminal stapling devices.
Malina
M
M
Department of Vascular Surgery, Lund University, Malmö University Hospital, Sweden.
Brunkwall
J
J
Lindblad
B
B
Resch
T
T
Ivancev
K
K
D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods*; D004108:Dilatation, Pathologic; D006801:Humans; D012077:Renal Artery / Q000601:surgery; D015607:Stents