Limb kinking in supported and unsupported abdominal aortic stent-grafts

The occurrence of kinking of stent-graft limbs depends on the patient's anatomy and the device used. The purpose of this investigation was to determine the rates of limb kinking in supported and unsupported aortic stent-grafts.

The authors performed a retrospective review of patients undergoing placement of either a Guidant Ancure/EGS or Medtronic Talent aortic stent-graft for the treatment of abdominal aortic aneurysm as part of separate phase II and phase III clinical trials. The records of 91 consecutive patients with 149 limbs were reviewed. The type and configuration of each device and any procedure performed specifically relating to limb patency was recorded. An analysis was then performed comparing the rates of kinking in supported and unsupported groups. A review of the literature was also performed.

Overall, there was kinking in 18 of 149 limbs (12%). In the supported stent-graft group, 48 bifurcated and 26 aortomonoiliac grafts were placed, with a total of 122 limbs at risk. Six limbs (5%) in five patients required intervention as a result of limb kinking. Stents were placed intraoperatively in two limbs (2%) and postoperatively in four limbs (3%) for thrombosis or severe stenosis. In the unsupported group, 12 bifurcated and three aortomonoiliac grafts were placed, with a total of 27 limbs at risk. Twelve limbs (44%) in eight patients required some type of intervention as a result of limb kinking. Stents were placed intraoperatively in seven limbs (26%) and postoperatively in five limbs (19%) for thrombosis or severe stenosis. Rates of limb kinking were significantly different between the supported and unsupported groups (P < .0001).

The use of supported versus unsupported stent-grafts impacts the occurrence of limb kinking. A direct comparison of the groups suggests that an unsupported stent-graft will be more than 15 times more likely than a supported system to require intervention because of kinking.