Carbon dioxide-enhanced CT-guided placement of aortic stent-grafts: feasibility in an animal model.

Purpose: To test the feasibility of carbon dioxide (CO(2))-enhanced computed tomography (CT)-guided placement of infrarenal abdominal aortic stent-grafts in an animal model.
Methods: Appearance of a stent-graft mounted on its deployment system and the feasibility of CT fluoroscopy-guided placement were analyzed in an in vitro setting. Five domestic pigs weighing 70 to 80 kg underwent CO(2)-enhanced 64-slice CT arteriography (CTA). After surgical exposure of the right iliac artery, an 18-mm stent-graft was advanced into the abdominal aorta. Infrarenal position of the graft was monitored using CT fluoroscopy with CO(2) administered intermittently in a flow-regulated manner using a computer-controlled injection system. After the final position of the stent-graft was determined, the graft was deployed under CT fluoroscopy guidance. Graft position was confirmed by contrast enhanced 64-slice CTA and conventional catheter angiography. To quantitatively assess the position of the stent-graft, the distance between the proximal stent struts and the radiopaque marker was determined using an electronic caliper.
Results: CT-guided placement of infrarenal aortic stent-grafts was feasible in all animals without complications. CO(2)-enhanced CTA allowed for the identification of the renal arteries in all animals. CT fluoroscopy permitted the continuous online monitoring of stent deployment. In all animals, the grafts were placed without impairment of renal artery flow or stent-graft dislocation. The mean distance between the stent-graft and origin of the more caudal renal artery was 0.9+/-0.3 mm.
Conclusion: CO(2)-enhanced CT fluoroscopy permits the precise placement of infrarenal aortic stent-grafts in an animal model.