The Impact of Optimal Fish-Mouth Fixation with an AORFIX AAA Endograft Combined with the AORFIX Technique: an Experimental Study

Abstract

Objective: The presence of a short, angulated neck in endovascular aneurysm repair remains challenging. The fish-mouth shape of the AORFIX AAA endograft enables trans-renal fixation, which can be advantageous in such cases. However, it is difficult to align the bottom line of the fish-mouth in a renal artery with an angulated neck. Here we devised a breakthrough technique to facilitate accurate fish-mouth positioning and achieved positive results. We then observed the ex vivo behavior of fish-mouth fixation of the AORFIX AAA endograft using this technique. Methods: A model of an abdominal aorta with a renal artery was created of porcine aortic vessels. Typical proximal touch-up ballooning was performed for reference. Kissing touch-up ballooning, which we named the Aligning Orifice of the Renal artery with fish-mouth FIXation (AORFIX) technique, between the aorta and the renal artery was performed as an interventional model. Results: In the reference model in which the endograft was deployed just below the renal artery, the bottom line of the fish-mouth was raised to cover the renal artery via touch-up ballooning. Unfortunately, its position did not improve with balloon angioplasty of the renal artery because the ring stents returned to the covered position after balloon deflation. In another reference model in which the endograft was deployed far enough below the renal artery, the bottom line of fish-mouth wasn't raised beyond that. In the interventional model with the AORFIX technique, the bottom line of the fish-mouth was anchored at the lower end of the renal artery orifice. The ring stents were shaped to fit the orifice, and clearance of the renal artery was secured. Conclusion: This ex vivo observations of fish-mouth behavior support our surgical experiences. The AORFIX technique effectively affixed the fish-mouth to the renal artery orifice and created a longer-lasting effect. These results suggest that the AORFIX technique can be a good option in cases of challenging endovascular aneurysm repair with a short, angulated neck.