Fixation of infrarenal aortic stent-grafts using laparoscopic banding -- an experimental study in pigs

PURPOSE: to test whether a laparoscopically-placed external band around the infrarenal aorta could stop vessel dilatation and prevent stent-graft detachment from the aortic wall. METHODS: in 13 growing pigs Gianturco-based stent-grafts were placed in the infrarenal aorta. In eight pigs, an external PTFE band (1 cm width) was placed laparoscopically around the infrarenal aorta. The remaining five pigs served as controls. Angiographic aortic diameters were measured: (1) at the most distal renal artery; (2) 1.5 cm further distally; (3) at the middle of the stent-graft; and (4) below the stent-graft, 1 cm above the aortic bifurcation. RESULTS: at a median follow-up of 16 weeks the pigs in the control group (n =5) and in the banded group ( n =7) increased their weight from 24 kg to 107 kg and 23 to 83 kg, respectively. In the control group, aortic dimensions increased by approximately 40% at all levels. In the banded group, aortic dimensions were unchanged at levels 2 and 3, but increased significantly at levels 1 and 4 (i.e. above and below the stent-graft). In the control group all stent-grafts detached causing a proximal perigraft leakage. No detachment or proximal perigraft leak was observed in the banded group. CONCLUSION: a laparoscopically placed external band around the infrarenal aorta of growing pigs seems to counteract the vessel dilatation and thereby provides a stable fixation of self-expandable stent-grafts.