Comparison Between Standard and High Density Resilient AneuRx in Reducing Aneurysm Sac Pressure in a Canine Model

[Object]Low Intra-Aneurysm Sac pressure has been shown to correlate with sac shrinkage following endovascular aneurysm repair(EVAR) whereas high pressure results in sac enlargement. The Resilient AneuRx (RSA) has higher density Dacron compared with the standard AneuRx (STA) and was developed in an attempt to reduce type 4 and 5 endoleaks thereby more effectively reducing sac pressure. The purpose of this study is to compare the ability of RSA and STA in reducing sac pressure in a chronic canine aneurysm model.
[Materials and Methods]Artificial (PTFE) aneurysm with a wireless pressure sensor attached to the inner surface was implanted in the abdominal aorta of ten hounds dogs. Two weeks after creation of the aneurysm, each animal underwent EVAR with either STA (n=5) or RSA (n=5). Following EVAR, intra-sac pressure was measured with the wireless sensor up to 3 months postoperatively.
[Results]EVAR was successful with no signs of an Endoleak in all ten dogs. Intra-sac pressure remained at a high level in the STA group whereas it gradually lowered over time in the RSA group.. This difference reached statistical significance at 2months and lasted to 3months. No Endoleak was detected in either group at the time of sacrifice.
[Conclusions]Despite absence of an endoleak, intra-sac pressure remained high in the STA group. RSA effectively reduced sac pressure over time. Wireless pressure sensor was reliable and worked well in this model. Graft porosity appears to be an important factor that may determine the outcome of EVAR. These findings may be useful in designing improved endograft.